1875 lines
84 KiB
Plaintext
1875 lines
84 KiB
Plaintext
处理第 1/821 条数据...
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处理第 2/821 条数据...
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处理第 3/821 条数据...
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\(6.69 \times 10^{21}\) atoms
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处理第 4/821 条数据...
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(i) in lead: \(3.3 \times 10^{22}\) atoms/cm\(^3\).
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(ii) in lithium: \(4.63 \times 10^{22}\) atoms/cm\(^3\).
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处理第 5/821 条数据...
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\(9.79 \times 10^{27}\) atoms/ton
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处理第 6/821 条数据...
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4.7 \mathrm{~cm}^{3}
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处理第 7/821 条数据...
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(a) \(5.98 \times 10^{23}\) atoms
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(b) \(0.994\) mol ni required
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处理第 8/821 条数据...
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there must be 7 electrons in the \(3 d\) energy level.
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处理第 9/821 条数据...
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the fraction of bonding of \(\mathrm{mgo}\) that is ionic is \(0.734\). so bonding is mostly ionic.
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处理第 10/821 条数据...
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处理第 11/821 条数据...
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(a) the atomic radius is \(1.426 \times 10^{-8}\) cm.
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(b) the atomic radius is \(1.4447 \times 10^{-8}\) cm.
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处理第 12/821 条数据...
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(a) the crystal structure is fcc.
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(b) the crystal structure is bcc.
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处理第 13/821 条数据...
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(a) the lattice parameter is \(5.3355 \times 10^{-8} \text{cm}\).
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(b) the atomic radius of potassium is \(2.3103 \times 10^{-8} \text{cm}\).
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处理第 14/821 条数据...
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(a) the lattice parameter is \(5.0856 \times 10^{-8} \text{cm}\).
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(b) the atomic radius of thorium is \(1.7980 \times 10^{-8} \text{cm}\).
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处理第 15/821 条数据...
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the crystal structure of the metal is fcc.
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处理第 16/821 条数据...
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the crystal structure of the metal is bcc.
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处理第 17/821 条数据...
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indium has a body-centered tetragonal (bct) structure.
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处理第 18/821 条数据...
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(a) the volume of the unit cell is \(0.21226 \mathrm{~nm}^{3}\) or \(2.1226 \times 10^{-22} \mathrm{~cm}^{3}\).
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(b) the number of atoms in each unit cell is 6.
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处理第 19/821 条数据...
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(a) the number of atoms in each unit cell is \(8\) atoms/cell.
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(b) the packing factor in the unit cell is \(0.387\).
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处理第 20/821 条数据...
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(a) the number of atoms in each unit cell is 2 atoms/cell.
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(b) the packing factor in the unit cell is 0.77.
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处理第 21/821 条数据...
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(a) \(3.185 \times 10^{21}\) cells
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(b) \(6.37 \times 10^{21}\) atoms
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处理第 22/821 条数据...
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for (100):
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planar density \(= 0.0812 \times 10^{16}\) points/cm\(^2\)
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packing fraction \(= 0.589\)
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for (110):
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planar density \(= 0.1149 \times 10^{16}\) points/cm\(^2\)
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packing fraction \(= 0.833\)
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for (111):
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planar density \(= 0.0469 \times 10^{16}\) points/cm\(^2\)
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packing fraction \(= \frac{1/2}{0.866 a_{0}^{2}} \sqrt{3} a_{0} / 4\)
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there is no close-packed plane in bcc structures.
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处理第 23/821 条数据...
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the sheet is \(4.563 \times 10^{6} d_{111}\) spacings thick.
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处理第 24/821 条数据...
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the number of \(d_{111}\) spacings is 3.
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处理第 25/821 条数据...
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(a) the minimum radius of an atom that will fit into the tetrahedral interstitial site in fcc nickel is \(0.2797 \aa\).
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(b) the minimum radius of an atom that will fit into the octahedral interstitial site in bcc lithium is \(0.629 \aa\).
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处理第 26/821 条数据...
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the radius of the atom that will just fit into the octahedral site in fcc copper is \(0.529 \aa\).
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处理第 27/821 条数据...
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(a) \(\mathrm{y}_{2} \mathrm{o}_{3}\): cn=6
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(b) \(\mathrm{uo}_{2}\): cn=6
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(c) \(\mathrm{bao}\): cn=8
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(d) \(\mathrm{si}_{4} \mathrm{n}_{4}\): cn=4
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(e) \(\mathrm{geo}_{2}\): cn=4
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(f) \(\mathrm{mno}\): cn=6
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(g) \(\mathrm{mgs}\): cn=6
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(h) \(\mathrm{kbr}\): cn=6
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处理第 28/821 条数据...
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\(\mathrm{nio}\) is expected to have the sodium chloride structure.
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(a) the lattice parameter is \(4.02 \aa\).
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(b) the density is \(7.64 \mathrm{g/cm}^3\).
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(c) the packing factor is \(0.678\).
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处理第 29/821 条数据...
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\(\mathrm{uo}_{2}\) is expected to have the fluorite structure.
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(a) the lattice parameter is \(a_{0} = 5.2885 \, \aa\).
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(b) the density is \(\rho = 12.13 \, \text{g/cm}^{3}\).
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(c) the packing factor is \(\text{pf} = 0.624\).
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处理第 30/821 条数据...
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1. \(\mathrm{beo}\) has the zinc blende structure.
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2. (a) the lattice parameter is \(3.8567 \, \text{\aa}\).
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(b) the density is \(2.897 \, \text{g/cm}^3\).
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(c) the packing factor is \(0.684\).
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处理第 31/821 条数据...
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1. csbr is expected to have the cesium chloride structure.
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2. (a) the lattice parameter \( a_0 = 4.1916 \, \aa \).
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3. (b) the density \( \rho = 4.8 \, \text{g/cm}^3 \).
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4. (c) the packing factor \( \text{pf} = 0.693 \).
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处理第 32/821 条数据...
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for \(\mathrm{zns}\) on the (110) plane, the planar packing fraction (ppf) is \(0.492\).
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for \(\mathrm{caf}_{2}\) on the (110) plane, the planar packing fraction (ppf) is \(0.699\).
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处理第 33/821 条数据...
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(111) plane:
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- planar density (p.d.): \(0.1473 \times 10^{16}\) points/cm\(^2\)
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- planar packing fraction (ppf): 0.202
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- ions present: mg\(^{2+}\) and o\(^{2-}\)
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(222) plane:
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- planar density (p.d.): \(0.1473 \times 10^{16}\) points/cm\(^2\)
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- planar packing fraction (ppf): 0.806
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- ions present: mg\(^{2+}\) and o\(^{2-}\)
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处理第 34/821 条数据...
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the lattice parameter of the iron is \(0.2865 \mathrm{~nm}\).
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处理第 35/821 条数据...
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\(4.97 \times 10^{19}\) vacancies/cm\(^3\)
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处理第 36/821 条数据...
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the activation energy required to create vacancies in aluminum is \(12800 \text{ cal/mol}\).
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处理第 37/821 条数据...
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(a) the fraction of the lattice points that contain vacancies is \(0.0008\).
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(b) the total number of vacancies in a cubic centimeter is \(0.986 \times 10^{20} \text{ vacancies/cm}^{3}\).
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处理第 38/821 条数据...
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(a) \(1.157 \times 10^{20}\) vacancies/cm³
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(b) \(0.532\) g/cm³
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处理第 39/821 条数据...
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(a) the density is \(11.335 \mathrm{~g/cm^3}\).
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(b) the number of vacancies per gram of \(\mathrm{pb}\) is \(5.82 \times 10^{18} \text{ vacancies/g}\).
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处理第 40/821 条数据...
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the fraction of the atoms in the alloy that are tungsten is \(0.345\).
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处理第 41/821 条数据...
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the atomic percentage of tin present in the alloy is \(11.95\%\).
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处理第 42/821 条数据...
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\(8.265 \mathrm{~g} / \mathrm{cm}^{3}\)
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处理第 43/821 条数据...
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(a) the density is \(7.89 \mathrm{~g/cm}^{3}\).
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(b) the packing factor is \(0.681\).
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处理第 44/821 条数据...
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(a) the atomic fraction of hydrogen atoms is \(0.004\).
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(b) the number of unit cells required on average that contain hydrogen atoms is 123.5.
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处理第 45/821 条数据...
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(a) the number of anion vacancies per \(\mathrm{cm}^{3}\) is \(1.61 \times 10^{21}\) vacancies/cm\(^3\).
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(b) the density of the ceramic is \(4.205 \mathrm{~g/cm}^{3}\).
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处理第 46/821 条数据...
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(a) \(0.0535\) defects per unit cell.
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(b) \(2.517 \times 10^{20}\) defects per \(\text{cm}^3\).
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处理第 47/821 条数据...
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(a) \( b = 2.853 \, \text{\aa} \)
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(b) \( b = 2.889 \, \text{\aa} \)
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(c) \( b = 3.840 \, \text{\aa} \)
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处理第 48/821 条数据...
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the resolved shear stress acting on the (111) slip plane in the [t] and [t] slip directions is:
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1. for \(\lambda_{110}\): \(\tau = 0\)
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2. for \(\lambda_{011}\): \(\tau = 2040 \text{ psi}\) (active)
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3. for \(\lambda_{101}\): \(\tau = 2040 \text{ psi}\) (active)
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the slip systems that will become active first are \(\lambda_{011}\) and \(\lambda_{101}\).
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处理第 49/821 条数据...
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the magnitude of the applied stress required to cause slip to begin in the [1,-1,1] direction is:
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- on the (110) slip plane: \(\sigma = \infty\)
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- on the (011) slip plane: \(\sigma = 29,412\) psi
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- on the (101) slip plane: \(\sigma = 29,412\) psi
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处理第 50/821 条数据...
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(a) the constants in the hall-petch equation are \( k = 19.4 \, \text{psi}/\sqrt{d} \) and \( \sigma_o = 60,290 \, \text{psi} \).
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(b) the strength of the titanium when the grain size is reduced to \( 0.2 \times 10^{-6} \, \text{m} \) is \( 103,670 \, \text{psi} \).
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处理第 51/821 条数据...
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(a) 128 grains/in.\(^2\)
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(b) \(1.28 \times 10^{6}\) grains/in.\(^2\)
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处理第 52/821 条数据...
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the astm grain size number is 9.3.
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处理第 53/821 条数据...
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the astm grain size number is \( n = 3.6 \).
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处理第 54/821 条数据...
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\(\theta = 0.0328^{\circ}\)
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处理第 55/821 条数据...
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the jump rate at \(750^{\circ} \mathrm{c}\) is \(1.08 \times 10^{9}\) jumps/s.
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处理第 56/821 条数据...
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the fraction at \(1000^{\circ} \mathrm{c}\) is \(0.00155\).
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处理第 57/821 条数据...
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(a) the activation energy \(q\) is \(59,230 \text{ cal/mol}\).
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(b) the constant \(d_{0}\) is \(0.055 \text{ cm}^{2}/\text{s}\).
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处理第 58/821 条数据...
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(a) \(-0.02495\) at\% sb/cm
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(b) \(-1.246 \times 10^{19}\) sb atoms/cm\(^3 \cdot\) cm
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处理第 59/821 条数据...
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(a) \(-2000\) at\% zn/cm
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(b) \(-2032\) wt\% zn/cm
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处理第 60/821 条数据...
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(a) \(-1969 \times 10^{8}\) h atoms/cm\(^3 \cdot\)cm
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(b) \(0.33 \times 10^{8}\) h atoms/cm\(^2 \cdot\)s
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处理第 61/821 条数据...
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the flux of nitrogen through the foil is \(7.57 \times 10^{12}\) n atoms/cm\(^2 \cdot\) s.
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处理第 62/821 条数据...
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the nitrogen lost from the container per hour is \(1.245 \times 10^{-3} \, \text{g/h}\).
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处理第 63/821 条数据...
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the minimum thickness of the iron is \(0.179 \mathrm{~cm}\).
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处理第 64/821 条数据...
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the maximum allowable temperature is \(75 \mathrm{~k}\) (\(-198^{\circ} \mathrm{c}\)).
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处理第 65/821 条数据...
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the diffusion rate of oxygen ions in \(\mathrm{al}_{2}\mathrm{o}_{3}\) at \(1500^{\circ}\mathrm{c}\) is \(3.47 \times 10^{-16} \mathrm{cm}^{2}/\mathrm{s}\), while the diffusion rate of aluminum ions is \(2.48 \times 10^{-13} \mathrm{cm}^{2}/\mathrm{s}\).
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the difference in diffusion rates is due to the ionic radii: the oxygen ion has a larger radius (\(1.32 \aa\)) compared to the aluminum ion (\(0.51 \aa\)), making it easier for the smaller aluminum ion to diffuse in the ceramic.
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处理第 66/821 条数据...
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the diffusion coefficient of carbon in bcc iron at \(912^{\circ} \mathrm{c}\) is \(1.51 \times 10^{-6} \mathrm{~cm}^{2} / \mathrm{s}\), while in fcc iron it is \(1.92 \times 10^{-7} \mathrm{~cm}^{2} / \mathrm{s}\).
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the packing factor of the bcc lattice (0.68) is less than that of the fcc lattice; consequently, atoms are expected to be able to diffuse more rapidly in the bcc iron.
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处理第 67/821 条数据...
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(a) for bcc iron, the carbon content at \(0.05 \mathrm{~cm}\) beneath the surface is \(0.95 \% \mathrm{c}\).
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(b) for fcc iron, the carbon content at \(0.05 \mathrm{~cm}\) beneath the surface is \(0.95 \% \mathrm{c}\).
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faster diffusion occurs in the looser packed bcc structure, leading to the higher carbon content at point "x".
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处理第 68/821 条数据...
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the required temperature is \(1180 \mathrm{~k}\) or \(907^{\circ} \mathrm{c}\).
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处理第 69/821 条数据...
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the required time is \(51 \mathrm{min}\).
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处理第 70/821 条数据...
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the carbon content required at the surface of the steel is \(0.53 \% \mathrm{c}\).
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处理第 71/821 条数据...
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0.177 cm
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处理第 72/821 条数据...
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the maximum time that the steel part can operate is \(2.9 \text{ min}\).
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处理第 73/821 条数据...
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the nitrogen content at \(0.25 \mathrm{~mm}\) from the surface is \(0.049\% \mathrm{~n}\).
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处理第 74/821 条数据...
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12.8 min
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处理第 75/821 条数据...
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9.95 h
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处理第 76/821 条数据...
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667°c
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处理第 77/821 条数据...
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diffusion of oxygen is the slower of the two, due to the larger ionic radius of the oxygen.
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the time required at the lower temperature is \(955 \text{ min}\) or \(15.9 \text{ h}\).
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处理第 78/821 条数据...
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(a) the wire will plastically deform (48,100 psi).
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(b) no necking will occur (48,100 psi).
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处理第 79/821 条数据...
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the bar will plastically deform because the applied stress of \(500 \mathrm{mpa}\) exceeds the yield strength of \(400 \mathrm{mpa}\).
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the bar will experience necking because the applied stress of \(500 \mathrm{mpa}\) exceeds the tensile strength of \(480 \mathrm{mpa}\).
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处理第 80/821 条数据...
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the maximum force the rod can withstand is 1100 lb or 4891 n.
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处理第 81/821 条数据...
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the modulus of elasticity is \(44.4 \ \mathrm{gpa}\).
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the modulus of elasticity is \(6.44 \times 10^{6} \ \mathrm{psi}\).
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处理第 82/821 条数据...
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the force required is \(200,000 \mathrm{lb}\).
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处理第 83/821 条数据...
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the minimum width of the plate is \(8 \mathrm{~cm}\).
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处理第 84/821 条数据...
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the diameter of the opening should be \(1.995\) in.
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处理第 85/821 条数据...
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the final length of the bar is \(12.00298\) in.
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the final diameter of the bar is \(0.39997\) in.
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处理第 86/821 条数据...
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(a) flexural strength \(= 76,800 \, \text{psi}\)
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(b) flexural modulus \(= 22.14 \times 10^{6} \, \text{psi}\)
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处理第 87/821 条数据...
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(a) the force that caused the fracture is \(1327 \mathrm{~n}\).
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(b) the flexural strength is \(276 \mathrm{mpa}\).
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处理第 88/821 条数据...
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(a) the minimum distance between the supports is \(41 \mathrm{mm}\).
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the applied stress is \(61.5 \mathrm{mpa}\), which is less than the flexural strength of \(85 \mathrm{mpa}\); the polymer is not expected to fracture.
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处理第 89/821 条数据...
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the deflection at the moment the bar breaks is \(0.0278 \text{ in.}\).
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处理第 90/821 条数据...
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\( hb = 29.8 \)
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处理第 91/821 条数据...
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the tensile strength of the steel is \(194,000 \mathrm{psi}\).
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处理第 92/821 条数据...
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the applied stress required for the crack to cause failure is \(11,354 \mathrm{mpa}\).
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the tensile strength of the composite is \(550 \mathrm{mpa}\). any failure of the ceramic should be expected due to the massive overload, not because of the presence of the flaws.
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处理第 93/821 条数据...
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the size of the flaw that initiated fracture is \(0.093 \text{ in}\).
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处理第 94/821 条数据...
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the plane strain fracture toughness of the polymer is \(0.99 \text{mpa} \sqrt{\text{m}}\).
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处理第 95/821 条数据...
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the length of internal flaws is \(2a = 0.013\) in.
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our nondestructive test can detect flaws as small as 0.05 in. long, which is not smaller than the critical flaw size required for failure. thus our ndt test is not satisfactory.
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处理第 96/821 条数据...
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the fatigue strength at one million cycles is \(22 \text{mpa}\).
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the maximum stress is \(+22 \text{mpa}\), the minimum stress is \(-22 \text{mpa}\), and the mean stress is \(0 \text{mpa}\).
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a high frequency will cause heating of the polymer. as the temperature of the polymer increases, the fatigue strength will decrease. if the applied stress is not reduced, then the polymer will fail in a shorter time.
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处理第 97/821 条数据...
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the creep rate is \(0.4 \, \mathrm{n} / \mathrm{in} \cdot \mathrm{h}\).
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处理第 98/821 条数据...
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the rupture time at \(800^{\circ} \mathrm{c}\) is \(101660 \mathrm{~h}\).
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处理第 99/821 条数据...
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the activation energy \(q_{r}\) is \(117,000 \text{ cal/mol}\).
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the constant \(m\) for rupture is \(3.9\).
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处理第 100/821 条数据...
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\( t_{f} = 0.0925 \) in.
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处理第 101/821 条数据...
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the final diameter is \(0.152\) in.
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处理第 102/821 条数据...
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75% in both cases.
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处理第 103/821 条数据...
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(a) the critical radius of the nucleus required is \(6.65 \times 10^{-8} \mathrm{~cm}\).
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(b) the number of nickel atoms in the nucleus is 109 atoms.
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处理第 104/821 条数据...
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(a) the critical radius of the nucleus required is \(10.128 \times 10^{-8} \mathrm{~cm}\).
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(b) the number of iron atoms in the nucleus is 350 atoms.
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处理第 105/821 条数据...
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the number of atoms that would have to group together spontaneously for homogeneous nucleation of solid nickel is \(1.136 \times 10^{6}\).
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处理第 106/821 条数据...
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the number of atoms that would have to group together spontaneously for homogeneous nucleation of solid iron with an undercooling of \(15^{\circ} \mathrm{c}\) is \(7.676 \times 10^{6}\) atoms.
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处理第 107/821 条数据...
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(a) \(0.0333\)
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||
(b) \(0.333\)
|
||
|
||
(c) all dendritically.
|
||
处理第 108/821 条数据...
|
||
(a) \(0.0237\)
|
||
|
||
(b) \(0.337\)
|
||
|
||
(c) \(0.842\)
|
||
处理第 109/821 条数据...
|
||
(a) the mold constant in chvorinov's rule is \(41.48 \text{ min/in}^2\).
|
||
|
||
(b) the solidification time for the bar is \(0.60 \text{ min}\).
|
||
处理第 110/821 条数据...
|
||
the solidification time for the plate is \(31.15 \mathrm{~s}\).
|
||
处理第 111/821 条数据...
|
||
the diameter of the riser \( d \geq 6.67 \) in.
|
||
|
||
the height of the riser \( h \geq 10 \) in.
|
||
|
||
the volume of the riser \( v \geq 349 \) in.\(^3\)
|
||
处理第 112/821 条数据...
|
||
the diameter of the riser must be at least \(2.25\) in.
|
||
|
||
the height of the riser must be at least \(2.25\) in.
|
||
|
||
the volume of the riser must be at least \(8.95\) in\(^3\).
|
||
处理第 113/821 条数据...
|
||
for copper:
|
||
- shrinkage volume: \(1.709\) in.\(^{3}\)
|
||
- diameter of shrinkage cavity: \(1.30\) in.
|
||
|
||
for iron:
|
||
- shrinkage volume: \(1.139\) in.\(^{3}\)
|
||
- diameter of shrinkage cavity: \(1.30\) in.
|
||
处理第 114/821 条数据...
|
||
the percent volume change that occurs during solidification is \(2.7\%\).
|
||
处理第 115/821 条数据...
|
||
(a) the volume of the shrinkage cavity at the center of the casting is \(46.03 \mathrm{~cm}^3\).
|
||
|
||
(b) the percent shrinkage that must have occurred during solidification is \(4.1\%\).
|
||
处理第 116/821 条数据...
|
||
(a) the percent shrinkage that must have occurred during solidification is \(3.4\%\).
|
||
|
||
(b) the number of shrinkage pores in the casting is \(83,\!354\) pores.
|
||
处理第 117/821 条数据...
|
||
the length of the casting immediately after solidification is completed is \(23.04 \mathrm{~cm}\).
|
||
处理第 118/821 条数据...
|
||
the percent volume change during solidification is \(0.77\%\).
|
||
|
||
the cast iron contracts during solidification.
|
||
处理第 119/821 条数据...
|
||
2.699%
|
||
处理第 120/821 条数据...
|
||
处理第 121/821 条数据...
|
||
处理第 122/821 条数据...
|
||
处理第 123/821 条数据...
|
||
处理第 124/821 条数据...
|
||
\(\mathrm{cr}_{2} \mathrm{o}_{3}\) is expected to have the largest solid solubility in \(\mathrm{al}_{2} \mathrm{o}_{3}\); in fact, they are completely soluble in one another.
|
||
处理第 125/821 条数据...
|
||
541.7 g ni
|
||
处理第 126/821 条数据...
|
||
332 g of \(\mathrm{mgo}\)
|
||
处理第 127/821 条数据...
|
||
56.9 wt\% feo
|
||
处理第 128/821 条数据...
|
||
(a) l: \(49\% \text{w}\); \(\alpha: 70\% \text{w}\)
|
||
|
||
(b) not possible unless we know the original composition of the alloy.
|
||
处理第 129/821 条数据...
|
||
(a) l: 22% w; α: 42% w
|
||
|
||
(b) 33% w
|
||
处理第 130/821 条数据...
|
||
212 additional pounds of w must be added before any solid forms.
|
||
|
||
1200 additional pounds of w must be added to cause the entire bath to be solid.
|
||
处理第 131/821 条数据...
|
||
cu dissolves ni until the cu contains enough ni that it solidifies completely. when 10% ni is dissolved, freezing begins with \(x = 55.5 \text{ g ni}\). when 18% ni is dissolved, the bath is completely solid with \(x = 109.8 \text{ g ni}\).
|
||
处理第 132/821 条数据...
|
||
(a) \(80\% \text{mgo}\)
|
||
|
||
(b) \(35\% \text{mgo}\)
|
||
处理第 133/821 条数据...
|
||
(a) \(55\% w\)
|
||
|
||
(b) \(18\% w\)
|
||
处理第 134/821 条数据...
|
||
\(\mathrm{sicu}_{4}\)
|
||
处理第 135/821 条数据...
|
||
(a) \(8\% \text{sn}\)
|
||
|
||
(b) liquidus temperature \(=290^{\circ} \text{c}\), solidus temperature \(=240^{\circ} \text{c}\), solvus temperature \(=170^{\circ} \text{c}\), freezing range \(=50^{\circ} \text{c}\)
|
||
|
||
(c) \(l: 30\% \text{sn}\), \(\alpha: 12\% \text{sn}\); \(\% l=17\%\), \(\% \alpha=83\%\)
|
||
|
||
(d) \(\alpha: 15\% \text{sn}\); \(100\% \alpha\)
|
||
|
||
(e) \(\alpha: 2\% \text{pb}\), \(\beta: 100\% \text{sn}\); \(\% \alpha=87\%\), \(\% \beta=13\%\)
|
||
处理第 136/821 条数据...
|
||
(a) hypoeutectic
|
||
|
||
(b) \(14 \% \text{sn}\)
|
||
|
||
(c) \(\alpha: 19 \% \text{sn}\), \(l: 61.9 \% \text{sn}\)
|
||
\(\% \alpha = 63 \%\), \(\% l = 37 \%\)
|
||
|
||
(d) \(\alpha: 19 \% \text{sn}\), \(\beta: 97.5 \% \text{sn}\)
|
||
\(\% \alpha = 80 \%\), \(\% \beta = 20 \%\)
|
||
|
||
(e) primary \(\alpha: 19 \% \text{sn}\), \(\%\) primary \(\alpha = 63 \%\)
|
||
eutectic: \(61.9 \% \text{sn}\), \(\%\) eutectic \(= 37 \%\)
|
||
|
||
(f) \(\alpha: 2 \% \text{sn}\), \(\beta: 100 \% \text{sn}\)
|
||
\(\% \alpha = 66 \%\), \(\% \beta = 34 \%\)
|
||
处理第 137/821 条数据...
|
||
(a) hypereutectic
|
||
|
||
(b) \(98 \% \mathrm{sn}\)
|
||
|
||
(c) \(\beta: 97.5 \% \mathrm{sn}\), \(l: 61.9 \% \mathrm{sn}\)
|
||
\(\% \beta = 22.8 \%\), \(\% l = 77.2 \%\)
|
||
|
||
(d) \(\alpha: 19 \% \mathrm{sn}\), \(\beta: 97.5 \% \mathrm{sn}\)
|
||
\(\% \alpha = 35 \%\), \(\% \beta = 65 \%\)
|
||
|
||
(e) primary \(\beta: 97.5 \% \mathrm{sn}\), \(\%\) primary \(\beta = 22.8 \%\)
|
||
eutectic: \(61.9 \% \mathrm{sn}\), \(\%\) eutectic \(= 77.2 \%\)
|
||
|
||
(f) \(\alpha: 2 \% \mathrm{sn}\), \(\beta: 100 \% \mathrm{sn}\)
|
||
\(\% \alpha = 30 \%\), \(\% \beta = 70 \%\)
|
||
处理第 138/821 条数据...
|
||
(a) hypo eutectic
|
||
|
||
(b) \(1 \% \text{si}\)
|
||
|
||
(c) \(\alpha: 1.65 \% \text{si}, \quad l: 12.6 \% \text{si}, \quad \% \alpha=78.5 \%, \quad \% l=21.5 \%\)
|
||
|
||
(d) \(\alpha: 1.65 \% \text{si}, \quad \beta: 99.83 \% \text{si}, \quad \% \alpha=97.6 \%, \quad \% \beta=2.4 \%\)
|
||
primary \(\alpha: 1.65 \% \text{si}, \quad \%\) primary \(\alpha=78.5 \%\)
|
||
eutectic: \(12.6 \% \text{si}, \quad \%\) eutectic \(=21.5 \%\)
|
||
|
||
(e) \(\alpha: 0 \% \text{si}, \quad \beta: 100 \% \text{si}, \quad \% \alpha=96 \%, \quad \% \beta=4 \%\)
|
||
处理第 139/821 条数据...
|
||
(a) hyper eutectic
|
||
|
||
(b) 100% si
|
||
|
||
(c) β: 99.83% si, l: 12.6% si, %l: 85.8%, %β: 14.2%
|
||
|
||
(d) α: 1.65% si, β: 99.83% si, %α: 76.2%, %β: 23.8%
|
||
|
||
(e) primary β: 99.83% si, % primary β: 14.2%; eutectic: 12.6% si, % eutectic: 85.8%
|
||
|
||
(f) α: 0% si, β: 100% si, %α: 75%, %β: 25%
|
||
处理第 140/821 条数据...
|
||
56.15% sn
|
||
|
||
hypoeutectic
|
||
处理第 141/821 条数据...
|
||
15.85% si
|
||
|
||
hypereutectic
|
||
处理第 142/821 条数据...
|
||
\(x = 52\% \mathrm{sn}\)
|
||
处理第 143/821 条数据...
|
||
\(25.71 \% \text{si}\)
|
||
处理第 144/821 条数据...
|
||
(a) \(17.46\% \mathrm{li}\), hypereutectic
|
||
|
||
(b) \(\% \alpha_{\text{est}} = 64\%\) and \(\% \beta_{\text{est}} = 36\%\)
|
||
处理第 145/821 条数据...
|
||
1. total amount of \(\alpha = 60.5\%\), \(\beta = 39.5\%\).
|
||
|
||
2. microconstituents: primary \(\alpha = 27.7\%\), eutectic = 72.3\%.
|
||
|
||
3. fraction of total \(\alpha\) in the eutectic microconstituent \(f = 0.54\).
|
||
处理第 146/821 条数据...
|
||
(a) for the \(\mathrm{cu}-1.2 \%\) be alloy, solution treat between \(530^{\circ} \mathrm{c}\) and \(870^{\circ} \mathrm{c}\) (typical at \(780^{\circ} \mathrm{c}\)), quench, and age below \(530^{\circ} \mathrm{c}\) (typical at \(330^{\circ} \mathrm{c}\)).
|
||
|
||
(b) the amount of \(\gamma_{2}\) precipitate at \(400^{\circ} \mathrm{c}\) is \(5.4 \%\), and at room temperature, it is \(8.5 \%\).
|
||
处理第 147/821 条数据...
|
||
(a) \(795^\circ c\)
|
||
|
||
(b) primary \(\alpha\)-ferrite
|
||
|
||
(c)
|
||
\(\alpha: 0.0218\% c\), \(56.1\%\)
|
||
\(\gamma: 0.77\% c\), \(43.9\%\)
|
||
|
||
(d)
|
||
\(\alpha: 0.0218\% c\), \(93.3\%\)
|
||
\(\mathrm{fe}_3 \mathrm{c}: 6.67\% c\), \(4.9\%\)
|
||
|
||
(e)
|
||
primary \(\alpha: 0.0218\% c\), \(56.1\%\)
|
||
pearlite: \(0.77\% c\), \(43.9\%\)
|
||
处理第 148/821 条数据...
|
||
(a) \(880^{\circ} \text{c}\)
|
||
|
||
(b) primary \(\text{fe}_3 \text{c}\)
|
||
|
||
(c) \(\text{fe}_3 \text{c}: 6.67\% \text{c}, 6.4\%\); \(\gamma: 0.77\% \text{c}, 93.6\%\)
|
||
|
||
(d) \(\alpha: 0.0218\% \text{c}, 83\%\); \(\text{fe}_3 \text{c}: 6.67\% \text{c}, 17\%\)
|
||
|
||
(e) primary \(\text{fe}_3 \text{c}: 6.67\% \text{c}, 6.4\%\); pearlite: \(0.77\% \text{c}, 93.6\%\)
|
||
处理第 149/821 条数据...
|
||
the carbon content of the steel is \(0.53 \% \mathrm{c}\).
|
||
|
||
the steel is hypoeutectoid.
|
||
处理第 150/821 条数据...
|
||
the carbon content of the steel is \(1.20 \% \mathrm{c}\).
|
||
|
||
the steel is hypereutectoid.
|
||
处理第 151/821 条数据...
|
||
the carbon content of the steel is \(0.156 \% \text{c}\).
|
||
|
||
the steel is hypoeutectoid.
|
||
处理第 152/821 条数据...
|
||
the carbon content of the steel is \(1.124 \% \mathrm{c}\).
|
||
|
||
the steel is hypereutectoid.
|
||
处理第 153/821 条数据...
|
||
the carbon content of the steel is \(0.281 \% \mathrm{c}\).
|
||
处理第 154/821 条数据...
|
||
the carbon content of the steel is \(1.15 \% \mathrm{c}\).
|
||
处理第 155/821 条数据...
|
||
the temperature is about \(760^{\circ} \mathrm{c}\).
|
||
|
||
the overall carbon content of the steel is \(0.212 \% \mathrm{c}\).
|
||
处理第 156/821 条数据...
|
||
处理第 157/821 条数据...
|
||
处理第 158/821 条数据...
|
||
处理第 159/821 条数据...
|
||
处理第 160/821 条数据...
|
||
处理第 161/821 条数据...
|
||
处理第 162/821 条数据...
|
||
处理第 163/821 条数据...
|
||
处理第 164/821 条数据...
|
||
处理第 165/821 条数据...
|
||
处理第 166/821 条数据...
|
||
处理第 167/821 条数据...
|
||
处理第 168/821 条数据...
|
||
the variation in density for metals is about 1.3 orders of magnitude.
|
||
处理第 169/821 条数据...
|
||
处理第 170/821 条数据...
|
||
处理第 171/821 条数据...
|
||
处理第 172/821 条数据...
|
||
the average atomic weight of \(\mathrm{hf}\) is \(178.485 \mathrm{amu}\).
|
||
处理第 173/821 条数据...
|
||
the fraction-of-occurrence of \({ }^{79}\mathrm{br}\) is 0.507, and the fraction-of-occurrence of \({ }^{81}\mathrm{br}\) is 0.493.
|
||
处理第 174/821 条数据...
|
||
9
|
||
处理第 175/821 条数据...
|
||
处理第 176/821 条数据...
|
||
处理第 177/821 条数据...
|
||
处理第 178/821 条数据...
|
||
处理第 179/821 条数据...
|
||
the energy of attraction is \(-2.5 \times 10^{-19} \mathrm{j}\).
|
||
处理第 180/821 条数据...
|
||
处理第 181/821 条数据...
|
||
(a) the percent ionic character is \(0 \%\).
|
||
|
||
(b) because the percent ionic character is zero and this intermetallic compound is composed of two metals, the bonding is completely metallic.
|
||
处理第 182/821 条数据...
|
||
处理第 183/821 条数据...
|
||
the atomic radius is \(0.122 \mathrm{~nm}\).
|
||
处理第 184/821 条数据...
|
||
the metal with these characteristics is metal c, which has an atomic radius of \(0.155 \mathrm{~nm}\) and an fcc crystal structure.
|
||
处理第 185/821 条数据...
|
||
the volume of the unit cell is \(0.0271 \text{ nm}^3\).
|
||
处理第 186/821 条数据...
|
||
\[
|
||
v_{c}=0.258 \mathrm{~nm}^{3}
|
||
\]
|
||
处理第 187/821 条数据...
|
||
the crystal structure for rhodium is \(\mathrm{fcc}\).
|
||
处理第 188/821 条数据...
|
||
the theoretical density for \(\mathrm{nb}\) is \(8.48 \mathrm{~g} / \mathrm{cm}^{3}\).
|
||
|
||
the experimental density for \(\mathrm{nb}\) is \(8.57 \mathrm{~g} / \mathrm{cm}^{3}\).
|
||
处理第 189/821 条数据...
|
||
处理第 190/821 条数据...
|
||
处理第 191/821 条数据...
|
||
处理第 192/821 条数据...
|
||
处理第 193/821 条数据...
|
||
处理第 194/821 条数据...
|
||
处理第 195/821 条数据...
|
||
处理第 196/821 条数据...
|
||
处理第 197/821 条数据...
|
||
处理第 198/821 条数据...
|
||
处理第 199/821 条数据...
|
||
(a) the concentration of \(\mathrm{f}\) that must be added is \(18.0 \, \text{wt} \%\).
|
||
|
||
(b) the concentration of \(\mathrm{f}\) required to completely fluorinate the material is \(76.0 \, \text{wt} \%\).
|
||
处理第 200/821 条数据...
|
||
处理第 201/821 条数据...
|
||
处理第 202/821 条数据...
|
||
处理第 203/821 条数据...
|
||
处理第 204/821 条数据...
|
||
the energy for vacancy formation is \(115 \mathrm{kj/mol}\).
|
||
处理第 205/821 条数据...
|
||
the number of vacancies at \(463^{\circ} \mathrm{c}\) is \(5.45 \times 10^{22} \mathrm{~m}^{-3}\).
|
||
处理第 206/821 条数据...
|
||
处理第 207/821 条数据...
|
||
处理第 208/821 条数据...
|
||
处理第 209/821 条数据...
|
||
the concentration of carbon is \(11.8 \mathrm{kg} / \mathrm{m}^{3}\).
|
||
处理第 210/821 条数据...
|
||
the crystal structure is body-centered cubic.
|
||
处理第 211/821 条数据...
|
||
the concentration of \(\mathrm{v}\) that must be added to iron to yield a unit cell edge length of \(0.289 \mathrm{~nm}\) is \(12.9 \mathrm{wt} \%\).
|
||
处理第 212/821 条数据...
|
||
处理第 213/821 条数据...
|
||
the specimen's astm grain size number is \(4.9\).
|
||
处理第 214/821 条数据...
|
||
处理第 215/821 条数据...
|
||
处理第 216/821 条数据...
|
||
\[
|
||
j = \frac{[m]}{[a] \times [t] \times 3600} \text{ atoms per square meter per second}
|
||
\]
|
||
处理第 217/821 条数据...
|
||
\[
|
||
t = \frac{[m] \times 1000 \times 24}{[a] \times [j] \times 18 \times 10000} \text{ hours}
|
||
\]
|
||
处理第 218/821 条数据...
|
||
处理第 219/821 条数据...
|
||
the time necessary to achieve the same concentration at a \(8 \mathrm{~mm}\) position for an identical steel and at a carburizing temperature of \(1130^{\circ} \mathrm{c}\) is \(17.9 \mathrm{~h}\).
|
||
处理第 220/821 条数据...
|
||
处理第 221/821 条数据...
|
||
the resulting strain is \(2.92 \times 10^{-3}\).
|
||
处理第 222/821 条数据...
|
||
(a) the maximum load that may be applied without plastic deformation is \(86,700 \mathrm{n}\).
|
||
|
||
(b) the maximum length to which the specimen may be stretched without causing plastic deformation is \(131.30 \mathrm{mm}\).
|
||
处理第 223/821 条数据...
|
||
the elastic modulus of the steel is \(223 \text{ gpa}\) (\(31.3 \times 10^6 \text{ psi}\)).
|
||
处理第 224/821 条数据...
|
||
the relationship between elastic and shear moduli for most metals is approximately \(g=0.4 e\).
|
||
处理第 225/821 条数据...
|
||
the only candidate material that satisfies both conditions is the **steel alloy**, with an elongation of \(0.57 \mathrm{~mm}\).
|
||
处理第 226/821 条数据...
|
||
the true plastic strain expected for a total true plastic stress of \(330 \text{mpa}\) is \(0.383\).
|
||
处理第 227/821 条数据...
|
||
390 \(\mathrm{mpa}\)
|
||
处理第 228/821 条数据...
|
||
the flexural strength for this test is \(379 \text{mpa} (53,500 \text{psi})\).
|
||
|
||
since this value is less than the reported flexural strength of \(390 \text{mpa}\), fracture is not predicted. however, there is some chance of fracture due to variability in material strength.
|
||
处理第 229/821 条数据...
|
||
(a) the flexural strength for a completely nonporous specimen of this material is \(126 \text{ mpa}\).
|
||
|
||
(b) the flexural strength for a 0.10 volume fraction porosity is \(79.4 \text{ mpa}\).
|
||
处理第 230/821 条数据...
|
||
处理第 231/821 条数据...
|
||
处理第 232/821 条数据...
|
||
处理第 233/821 条数据...
|
||
处理第 234/821 条数据...
|
||
处理第 235/821 条数据...
|
||
处理第 236/821 条数据...
|
||
处理第 237/821 条数据...
|
||
处理第 238/821 条数据...
|
||
处理第 239/821 条数据...
|
||
处理第 240/821 条数据...
|
||
the time required for the specimen to achieve a grain diameter of \(5.5 \times 10^{-2} \mathrm{mm}\) is \(246 \mathrm{~min}\).
|
||
处理第 241/821 条数据...
|
||
the tensile strength for a number-average molecular weight of \(51500 \mathrm{~g/mol}\) is \(95.2 \mathrm{mpa}\).
|
||
处理第 242/821 条数据...
|
||
the estimated number average molecular weight at a tensile strength of \(141 \, \mathrm{mpa}\) is \(14600 \, \mathrm{g/mol}\).
|
||
处理第 243/821 条数据...
|
||
处理第 244/821 条数据...
|
||
处理第 245/821 条数据...
|
||
处理第 246/821 条数据...
|
||
处理第 247/821 条数据...
|
||
处理第 248/821 条数据...
|
||
处理第 249/821 条数据...
|
||
the ratio of the etched and original crack tip radii is:
|
||
|
||
\[
|
||
\frac{\rho_{t}^{\prime}}{\rho_{t}} = 32
|
||
\]
|
||
处理第 250/821 条数据...
|
||
the critical length of a surface flaw is \(2.0 \mathrm{mm}\).
|
||
处理第 251/821 条数据...
|
||
处理第 252/821 条数据...
|
||
处理第 253/821 条数据...
|
||
the plate will definitely fracture.
|
||
处理第 254/821 条数据...
|
||
处理第 255/821 条数据...
|
||
the maximum allowable surface crack length without fracture is \(1.55 \mathrm{mm}\).
|
||
处理第 256/821 条数据...
|
||
approximately \(815^\circ \mathrm{c}\).
|
||
处理第 257/821 条数据...
|
||
处理第 258/821 条数据...
|
||
处理第 259/821 条数据...
|
||
处理第 260/821 条数据...
|
||
处理第 261/821 条数据...
|
||
处理第 262/821 条数据...
|
||
处理第 263/821 条数据...
|
||
处理第 264/821 条数据...
|
||
处理第 265/821 条数据...
|
||
处理第 266/821 条数据...
|
||
the formula for this intermetallic compound is \(\mathrm{mg}_{2} \mathrm{ga}\).
|
||
处理第 267/821 条数据...
|
||
处理第 268/821 条数据...
|
||
处理第 269/821 条数据...
|
||
处理第 270/821 条数据...
|
||
处理第 271/821 条数据...
|
||
处理第 272/821 条数据...
|
||
3.29 electron/atom
|
||
处理第 273/821 条数据...
|
||
the number of free electrons donated by each atom, on average, is:
|
||
|
||
\[
|
||
\frac{[w]}{\left([r]\left(1.6 \times 10^{-19}\right)[m]\right)\left([d]\left(6.022 \times 10^{23}\right)\right)}
|
||
\]
|
||
处理第 274/821 条数据...
|
||
处理第 275/821 条数据...
|
||
处理第 276/821 条数据...
|
||
处理第 277/821 条数据...
|
||
处理第 278/821 条数据...
|
||
处理第 279/821 条数据...
|
||
处理第 280/821 条数据...
|
||
处理第 281/821 条数据...
|
||
处理第 282/821 条数据...
|
||
处理第 283/821 条数据...
|
||
处理第 284/821 条数据...
|
||
处理第 285/821 条数据...
|
||
处理第 286/821 条数据...
|
||
\(\mu_{\mathrm{e}} = 0.50 \, \mathrm{m}^{2} / \mathrm{v} \cdot \mathrm{s}\)
|
||
|
||
\(\mu_{\mathrm{h}} = 0.02 \, \mathrm{m}^{2} / \mathrm{v} \cdot \mathrm{s}\)
|
||
处理第 287/821 条数据...
|
||
处理第 288/821 条数据...
|
||
处理第 289/821 条数据...
|
||
处理第 290/821 条数据...
|
||
处理第 291/821 条数据...
|
||
处理第 292/821 条数据...
|
||
处理第 293/821 条数据...
|
||
处理第 294/821 条数据...
|
||
处理第 295/821 条数据...
|
||
处理第 296/821 条数据...
|
||
处理第 297/821 条数据...
|
||
处理第 298/821 条数据...
|
||
处理第 299/821 条数据...
|
||
处理第 300/821 条数据...
|
||
处理第 301/821 条数据...
|
||
处理第 302/821 条数据...
|
||
the minimum fiber length to guarantee that the fibers are conveying an optimum fraction of force that is applied to the composite is \(\frac{[f][d]}{2[s] \times 1000}\) millimeters.
|
||
处理第 303/821 条数据...
|
||
处理第 304/821 条数据...
|
||
处理第 305/821 条数据...
|
||
处理第 306/821 条数据...
|
||
处理第 307/821 条数据...
|
||
处理第 308/821 条数据...
|
||
处理第 309/821 条数据...
|
||
处理第 310/821 条数据...
|
||
处理第 311/821 条数据...
|
||
处理第 312/821 条数据...
|
||
处理第 313/821 条数据...
|
||
处理第 314/821 条数据...
|
||
处理第 315/821 条数据...
|
||
处理第 316/821 条数据...
|
||
处理第 317/821 条数据...
|
||
处理第 318/821 条数据...
|
||
处理第 319/821 条数据...
|
||
处理第 320/821 条数据...
|
||
处理第 321/821 条数据...
|
||
处理第 322/821 条数据...
|
||
处理第 323/821 条数据...
|
||
处理第 324/821 条数据...
|
||
处理第 325/821 条数据...
|
||
处理第 326/821 条数据...
|
||
处理第 327/821 条数据...
|
||
the final temperature is \(126^{\circ} \mathrm{c}\), which corresponds to answer \(\mathrm{c}\).
|
||
处理第 328/821 条数据...
|
||
the linear coefficient of thermal expansion for this material is \(7.92 \times 10^{-6} \left(^{\circ}c\right)^{-1}\), which is answer b.
|
||
处理第 329/821 条数据...
|
||
\[
|
||
\sigma_{th} = (193,000)(16 \times 10^{-6})([i] - [f]) \mathrm{mpa}
|
||
\]
|
||
处理第 330/821 条数据...
|
||
polystyrene will experience the smallest temperature change.
|
||
处理第 331/821 条数据...
|
||
处理第 332/821 条数据...
|
||
处理第 333/821 条数据...
|
||
处理第 334/821 条数据...
|
||
处理第 335/821 条数据...
|
||
处理第 336/821 条数据...
|
||
the number of bohr magnetons associated with each \(\mathrm{y}^{3+}\) ion is \(1.75 \mathrm{bm}\).
|
||
处理第 337/821 条数据...
|
||
处理第 338/821 条数据...
|
||
处理第 339/821 条数据...
|
||
处理第 340/821 条数据...
|
||
处理第 341/821 条数据...
|
||
处理第 342/821 条数据...
|
||
处理第 343/821 条数据...
|
||
处理第 344/821 条数据...
|
||
处理第 345/821 条数据...
|
||
处理第 346/821 条数据...
|
||
处理第 347/821 条数据...
|
||
处理第 348/821 条数据...
|
||
处理第 349/821 条数据...
|
||
处理第 350/821 条数据...
|
||
处理第 351/821 条数据...
|
||
处理第 352/821 条数据...
|
||
处理第 353/821 条数据...
|
||
the band gap of the material is \(4.135 \times 10^{-3} [f]\) ev.
|
||
处理第 354/821 条数据...
|
||
处理第 355/821 条数据...
|
||
处理第 356/821 条数据...
|
||
处理第 357/821 条数据...
|
||
处理第 358/821 条数据...
|
||
the average atomic weight of \(\mathrm{cr}\) is \(51.9963 \, \mathrm{amu}\).
|
||
处理第 359/821 条数据...
|
||
(a) \(1.66 \times 10^{-24}\) g/amu
|
||
|
||
(b) \(2.73 \times 10^{26}\) atoms/lb-mol
|
||
处理第 360/821 条数据...
|
||
处理第 361/821 条数据...
|
||
处理第 362/821 条数据...
|
||
处理第 363/821 条数据...
|
||
处理第 364/821 条数据...
|
||
处理第 365/821 条数据...
|
||
处理第 366/821 条数据...
|
||
处理第 367/821 条数据...
|
||
处理第 368/821 条数据...
|
||
处理第 369/821 条数据...
|
||
the force of attraction between the \(\mathrm{k}^{+}\) and \(\mathrm{o}^{2-}\) ions is \(2.05 \times 10^{-10} \mathrm{n}\).
|
||
处理第 370/821 条数据...
|
||
处理第 371/821 条数据...
|
||
处理第 372/821 条数据...
|
||
处理第 373/821 条数据...
|
||
the volume of the unit cell is \(6.62 \times 10^{-29} \mathrm{m}^{3}\).
|
||
处理第 374/821 条数据...
|
||
the atomic packing factor for bcc is 0.68.
|
||
处理第 375/821 条数据...
|
||
the theoretical density of iron is \(7.90 \mathrm{~g} / \mathrm{cm}^{3}\).
|
||
|
||
the experimental value given inside the front cover is \(7.87 \mathrm{~g} / \mathrm{cm}^{3}\).
|
||
处理第 376/821 条数据...
|
||
the radius of an iridium atom is \(0.136 \mathrm{~nm}\).
|
||
处理第 377/821 条数据...
|
||
the radius of a vanadium atom is \(0.132 \mathrm{nm}\).
|
||
处理第 378/821 条数据...
|
||
for alloy a, its crystal structure is simple cubic.
|
||
|
||
for alloy b, its crystal structure is fcc.
|
||
|
||
for alloy c, its crystal structure is simple cubic.
|
||
处理第 379/821 条数据...
|
||
the atomic packing factor (apf) for tin is \(0.534\).
|
||
处理第 380/821 条数据...
|
||
处理第 381/821 条数据...
|
||
处理第 382/821 条数据...
|
||
处理第 383/821 条数据...
|
||
the (010) plane in the four-index miller-bravais scheme is \(\left(01 \overline{-1} 0\right)\).
|
||
|
||
the (101) plane in the four-index miller-bravais scheme is \(\left(10 \overline{-1} 1\right)\).
|
||
处理第 384/821 条数据...
|
||
(a) the planar density expression for the hcp (0001) plane in terms of the atomic radius \(r\) is:
|
||
|
||
\[
|
||
\text{pd}_{0001} = \frac{1}{2 r^{2} \sqrt{3}}
|
||
\]
|
||
|
||
(b) the planar density value for the (0001) plane for magnesium is:
|
||
|
||
\[
|
||
\text{pd}_{0001}(\text{mg}) = 1.128 \times 10^{19} \text{m}^{-2}
|
||
\]
|
||
处理第 385/821 条数据...
|
||
处理第 386/821 条数据...
|
||
(a) the interplanar spacing for the (220) set of planes for iridium is \(0.1357 \text{ nm}\).
|
||
|
||
(b) the atomic radius for an iridium atom is \(0.1357 \text{ nm}\).
|
||
处理第 387/821 条数据...
|
||
处理第 388/821 条数据...
|
||
the composition of the alloy is \(29.4 \, \text{at} \% \, \mathrm{zn}\) and \(70.6 \, \text{at} \% \, \mathrm{cu}\).
|
||
处理第 389/821 条数据...
|
||
the composition of the alloy is:
|
||
|
||
1. \(10.0 \, \text{wt\% pb}\)
|
||
|
||
2. \(90.0 \, \text{wt\% sn}\)
|
||
处理第 390/821 条数据...
|
||
the composition of the alloy in atom percent is:
|
||
|
||
\[
|
||
c_{\mathrm{cu}} = 50.0 \, \text{at} \%
|
||
\]
|
||
|
||
\[
|
||
c_{\mathrm{zn}} = 49.7 \, \text{at} \%
|
||
\]
|
||
|
||
\[
|
||
c_{\mathrm{pb}} = 0.3 \, \text{at} \%
|
||
\]
|
||
处理第 391/821 条数据...
|
||
the composition of the alloy is 94.2 at\% fe and 5.8 at\% si.
|
||
处理第 392/821 条数据...
|
||
\(6.05 \times 10^{28}\) atoms/m\(^3\)
|
||
处理第 393/821 条数据...
|
||
the concentration of carbon in the alloy is \(11.8 \mathrm{kg/m^{3}}\).
|
||
处理第 394/821 条数据...
|
||
处理第 395/821 条数据...
|
||
处理第 396/821 条数据...
|
||
处理第 397/821 条数据...
|
||
处理第 398/821 条数据...
|
||
处理第 399/821 条数据...
|
||
处理第 400/821 条数据...
|
||
处理第 401/821 条数据...
|
||
the time necessary to achieve a carbon concentration of \(0.45 \text{wt}\%\) at a \(5.0 \text{mm}\) position is \(40 \text{h}\).
|
||
处理第 402/821 条数据...
|
||
the temperature at which the diffusion coefficient has a value of \(2.1 \times 10^{-14} \mathrm{m}^{2}/\mathrm{s}\) is \(1518 \mathrm{k}\) (\(1245^{\circ} \mathrm{c}\)).
|
||
|
||
alternatively, using the vmse software, the temperature is found to be \(1519 \mathrm{k}\).
|
||
处理第 403/821 条数据...
|
||
the diffusion coefficient at \(1100 \mathrm{~k}\) is \(4.6 \times 10^{-12} \mathrm{~m}^{2} / \mathrm{s}\).
|
||
处理第 404/821 条数据...
|
||
(a) the values are \(d_{0} = 2.2 \times 10^{-5} \, \text{m}^2/\text{s}\) and the activation energy \(q_{d} = 252,400 \, \text{j/mol}\).
|
||
|
||
(b) the magnitude of \(d\) at \(1100^{\circ} \text{c} (1373 \, \text{k})\) is \(5.4 \times 10^{-15} \, \text{m}^2/\text{s}\).
|
||
处理第 405/821 条数据...
|
||
(a) the values are \(d_{0} = 7.5 \times 10^{-5} \, \text{m}^2/\text{s}\) and \(q_{d} = 196,700 \, \text{j/mol}\).
|
||
|
||
(b) the magnitude of \(d\) at \(875^{\circ} \text{c}\) is \(8.3 \times 10^{-14} \, \text{m}^2/\text{s}\).
|
||
处理第 406/821 条数据...
|
||
the temperature at which the diffusion flux is \(1.43 \times 10^{-9} \mathrm{~kg} / \mathrm{m}^{2}\)-s is \(1044 \mathrm{~k}\) or \(771^{\circ} \mathrm{c}\).
|
||
处理第 407/821 条数据...
|
||
the diffusion flux at \(1027^{\circ} \mathrm{c} (1300 \mathrm{k})\) is \(1.74 \times 10^{-8} \mathrm{kg/m^{2}-s}\).
|
||
处理第 408/821 条数据...
|
||
(a) the maximum load that may be applied without plastic deformation is \(89,375 \mathrm{n}\) (20,000 \(\mathrm{lb}_{\mathrm{f}}\)).
|
||
|
||
(b) the maximum length to which the specimen may be stretched without causing plastic deformation is \(115.28 \mathrm{mm}\) (4.51 \(\mathrm{in}\)).
|
||
处理第 409/821 条数据...
|
||
the diameter must be \(7.65 \mathrm{~mm}\) (0.30 \(\mathrm{in}\)).
|
||
处理第 410/821 条数据...
|
||
(a) the elastic modulus for titanium is \(106.4 \mathrm{gpa}\), which is in very good agreement with the value of \(107 \mathrm{gpa}\) from table 6.1.
|
||
|
||
(b) the elastic modulus for tempered steel is \(204.7 \mathrm{gpa}\), which is in reasonably good agreement with the value of \(207 \mathrm{gpa}\) from table 6.1.
|
||
|
||
(c) the elastic modulus for aluminum is \(69.1 \mathrm{gpa}\), which is in excellent agreement with the value of \(69 \mathrm{gpa}\) from table 6.1.
|
||
|
||
(d) the elastic modulus for carbon steel is \(215 \mathrm{gpa}\), which is in reasonable agreement with the value of \(207 \mathrm{gpa}\) from table 6.1.
|
||
处理第 411/821 条数据...
|
||
the modulus of elasticity for this alloy is \(1.705 \times 10^{11}\) pa or 170.5 gpa.
|
||
处理第 412/821 条数据...
|
||
of the alloys listed, the steel alloy is a possible candidate because it meets both criteria.
|
||
|
||
the titanium alloy is not a candidate as it fails the second criterion regarding diameter reduction.
|
||
处理第 413/821 条数据...
|
||
the ductility in terms of percent reduction in area is \(73.4\%\).
|
||
|
||
the ductility in terms of percent elongation is \(42\%\).
|
||
处理第 414/821 条数据...
|
||
the specimen will elongate by \(58.8 \text{ mm}\) (\(2.31 \text{ in}\)).
|
||
处理第 415/821 条数据...
|
||
处理第 416/821 条数据...
|
||
for a dislocation density of \(10^{4} \mathrm{mm}^{-2}\), the chain would extend \(6.2\) miles.
|
||
|
||
for a dislocation density of \(10^{10} \mathrm{mm}^{-2}\), the chain would extend \(6.2 \times 10^{6}\) miles.
|
||
处理第 417/821 条数据...
|
||
处理第 418/821 条数据...
|
||
处理第 419/821 条数据...
|
||
the resolved shear stress is \(22.0 \mathrm{mpa}\) (3181 psi). since this is greater than the critical resolved shear stress of \(20.7 \mathrm{mpa}\) (3000 psi), the single crystal will yield.
|
||
处理第 420/821 条数据...
|
||
(a) the most favored slip direction is at an angle of \(62.4^{\circ}\) with the tensile axis.
|
||
|
||
(b) the critical resolved shear stress for aluminum is \(0.80 \mathrm{mpa}\) (114 psi).
|
||
处理第 421/821 条数据...
|
||
the maximum possible yield strength for a single crystal of \(\mathrm{fe}\) pulled in tension is \(54 \mathrm{mpa}\) (8000 \(\mathrm{psi}\)).
|
||
处理第 422/821 条数据...
|
||
处理第 423/821 条数据...
|
||
处理第 424/821 条数据...
|
||
处理第 425/821 条数据...
|
||
the second specimen's radius after deformation is \(8.25 \mathrm{~mm}\).
|
||
处理第 426/821 条数据...
|
||
the hardest specimen will be the deformed circular one with a cold work percentage of \(43.8\%\).
|
||
处理第 427/821 条数据...
|
||
the radius before deformation was \(10.6 \mathrm{~mm}\) (0.424 in.).
|
||
处理第 428/821 条数据...
|
||
处理第 429/821 条数据...
|
||
the magnitude of the maximum stress at the tip of the internal crack is \(2404 \text{ mpa}\) (\(354,000 \text{ psi}\)).
|
||
处理第 430/821 条数据...
|
||
the theoretical fracture strength is \(3.5 \times 10^{4} \mathrm{mpa}\) (\(5.1 \times 10^{6} \mathrm{psi}\)).
|
||
处理第 431/821 条数据...
|
||
the critical stress required for the propagation of a surface crack of length \(0.05 \mathrm{mm}\) is \(16.2 \mathrm{mpa}\).
|
||
处理第 432/821 条数据...
|
||
the maximum allowable surface crack length is \(6.1 \times 10^{-4} \, \text{m}\) (0.61 mm or 0.024 in.).
|
||
处理第 433/821 条数据...
|
||
the specimen will experience fracture because it can only tolerate a stress of \(927 \text{mpa} (133,500 \text{psi})\) before fracture, which is less than the applied stress of \(1000 \text{mpa} (145,000 \text{psi})\).
|
||
处理第 434/821 条数据...
|
||
fracture will not occur since the value \(32.2 \mathrm{mpa} \sqrt{\mathrm{m}}\) is less than the fracture toughness \(k_{ic}\) of the material, \(35 \mathrm{mpa} \sqrt{\mathrm{m}}\).
|
||
处理第 435/821 条数据...
|
||
the stress level at which fracture will occur for a critical internal crack length of \(4.0 \mathrm{~mm}\) is \(288 \mathrm{mpa}\) (41,500 \(\mathrm{psi}\)).
|
||
处理第 436/821 条数据...
|
||
the minimum length of a surface crack that will lead to fracture is \(0.024 \, \text{m}\) (24 mm).
|
||
处理第 437/821 条数据...
|
||
the maximum internal crack length allowable is \(0.0033 \, \text{m}\) (3.3 mm).
|
||
处理第 438/821 条数据...
|
||
the critical flaw size \(a_c\) is \(3.9 \mathrm{mm}\). therefore, the critical flaw is not subject to detection since it is less than the \(4.0 \mathrm{mm}\) resolution limit.
|
||
处理第 439/821 条数据...
|
||
处理第 440/821 条数据...
|
||
处理第 441/821 条数据...
|
||
处理第 442/821 条数据...
|
||
for ni: \(418^{\circ} \mathrm{c}\) (\(785^{\circ} \mathrm{f}\))
|
||
|
||
for cu: \(270^{\circ} \mathrm{c}\) (\(518^{\circ} \mathrm{f}\))
|
||
|
||
for fe: \(450^{\circ} \mathrm{c}\) (\(845^{\circ} \mathrm{f}\))
|
||
|
||
for w: \(1200^{\circ} \mathrm{c}\) (\(2190^{\circ} \mathrm{f}\))
|
||
|
||
for pb: \(-33^{\circ} \mathrm{c}\) (\(-27^{\circ} \mathrm{f}\))
|
||
|
||
for al: \(100^{\circ} \mathrm{c}\) (\(212^{\circ} \mathrm{f}\))
|
||
处理第 443/821 条数据...
|
||
处理第 444/821 条数据...
|
||
处理第 445/821 条数据...
|
||
the composition of the phase boundary for the \(\alpha\) phase is \(90 \text{ wt\% a-10 wt\% b}\).
|
||
|
||
the composition of the phase boundary for the \(\beta\) phase is \(20.2 \text{ wt\% a-79.8 wt\% b}\).
|
||
处理第 446/821 条数据...
|
||
the composition of the \(\alpha\) phase is \(20 \text{ wt}\% \text{ b- } 80 \text{ wt}\% \text{ a}\).
|
||
处理第 447/821 条数据...
|
||
yes, it is possible to have a \(30 \text{wt} \% \text{pb}-70 \text{wt} \% \text{mg}\) alloy with masses of \(7.39 \text{kg}\) and \(3.81 \text{kg}\) for the \(\alpha\) and \(\text{mg}_2 \text{pb}\) phases, respectively.
|
||
|
||
the approximate temperature of the alloy is \(190^\circ \text{c}\).
|
||
处理第 448/821 条数据...
|
||
处理第 449/821 条数据...
|
||
处理第 450/821 条数据...
|
||
处理第 451/821 条数据...
|
||
element \( b \) is arsenic (as), with an atomic weight of \( 74.92 \, \text{g/mol} \). the two intermetallic compounds are \( \text{kas} \) and \( \text{kas}_2 \).
|
||
处理第 452/821 条数据...
|
||
处理第 453/821 条数据...
|
||
the mass fraction of \(\alpha\) ferrite in pearlite is \(0.89\).
|
||
|
||
the mass fraction of cementite in pearlite is \(0.11\).
|
||
处理第 454/821 条数据...
|
||
处理第 455/821 条数据...
|
||
the carbon concentration of the iron-carbon alloy is \(0.42 \text{ wt\% c}\).
|
||
处理第 456/821 条数据...
|
||
the proeutectoid phase is \(\alpha\) ferrite because the alloy composition \(c_{0}\) is less than \(0.76 \mathrm{wt} \% \mathrm{c}\).
|
||
处理第 457/821 条数据...
|
||
(a) the proeutectoid phase is \(\mathrm{fe}_{3} \mathrm{c}\).
|
||
|
||
(b) the total ferrite formed is 0.83 kg, and the total cementite formed is 0.17 kg.
|
||
|
||
(c) the pearlite formed is 0.93 kg, and the proeutectoid phase (cementite) formed is 0.07 kg.
|
||
处理第 458/821 条数据...
|
||
(a) ferrite is the proeutectoid phase.
|
||
|
||
(b) the total ferrite formed is \(2.27 \mathrm{~kg}\), and the total cementite formed is \(0.23 \mathrm{~kg}\).
|
||
|
||
(c) the pearlite formed is \(2.12 \mathrm{~kg}\), and the proeutectoid ferrite formed is \(0.38 \mathrm{~kg}\).
|
||
处理第 459/821 条数据...
|
||
the mass fraction of proeutectoid ferrite is \(0.69\).
|
||
|
||
the mass fraction of pearlite is \(0.31\).
|
||
处理第 460/821 条数据...
|
||
\(0.55 \% \text{c}\)
|
||
处理第 461/821 条数据...
|
||
the alloy is hypereutectoid since \(c_0\) is greater than \(0.76 \, \text{wt\% c}\).
|
||
处理第 462/821 条数据...
|
||
the concentration of carbon in this alloy is \(0.61 \% \text{c}\).
|
||
处理第 463/821 条数据...
|
||
(a) \(0.98 \mathrm{~kg}\) of proeutectoid ferrite forms.
|
||
|
||
(b) \(0.90 \mathrm{~kg}\) of eutectoid ferrite forms.
|
||
|
||
(c) \(0.114 \mathrm{~kg}\) of cementite forms.
|
||
处理第 464/821 条数据...
|
||
the maximum mass fraction of proeutectoid cementite possible for a hypereutectoid iron-carbon alloy is \(0.232\).
|
||
处理第 465/821 条数据...
|
||
yes, it is possible to have an iron-carbon alloy with mass fractions of total ferrite \(w_{\alpha}=0.846\) and proeutectoid cementite \(w_{\mathrm{fe}_{3} \mathrm{c}^{\prime}}=0.049\).
|
||
|
||
the alloy composition for both conditions is \(1.05 \mathrm{wt} \% \mathrm{c}\). since the composition values are equal, such an alloy exists.
|
||
处理第 466/821 条数据...
|
||
no, such an iron-carbon alloy is not possible because the required carbon compositions for the given mass fractions of total cementite (\(0.28 \mathrm{wt} \% \mathrm{c}\)) and pearlite (\(0.33 \mathrm{wt} \% \mathrm{c}\)) are different.
|
||
处理第 467/821 条数据...
|
||
the mass fraction of eutectoid ferrite in the iron-carbon alloy is \(0.493\).
|
||
处理第 468/821 条数据...
|
||
yes, it is possible to determine the alloy composition, and there are two possible answers:
|
||
|
||
1. for the case where eutectoid cementite exists in addition to proeutectoid cementite, the alloy composition is \( c_0 = 1.11 \, \text{wt\% c} \).
|
||
|
||
2. for a hypoeutectoid alloy where all cementite is eutectoid cementite, the mass fraction of total cementite is set to 0.104. the composition can be determined using the lever rule.
|
||
处理第 469/821 条数据...
|
||
yes, it is possible to determine the alloy composition; and, in fact, there are two possible answers.
|
||
|
||
for the first case, the composition is \( c_0 = 0.70 \, \text{wt} \% \, \text{c} \).
|
||
|
||
for the second case, the composition is \( c_0 = 1.22 \, \text{wt} \% \, \text{c} \).
|
||
处理第 470/821 条数据...
|
||
处理第 471/821 条数据...
|
||
the critical radius is \(1.30 \mathrm{~nm}\).
|
||
处理第 472/821 条数据...
|
||
the total time required for \(95 \%\) of the austenite to transform to pearlite is \(35.7 \, \text{s}\).
|
||
处理第 473/821 条数据...
|
||
the fraction recrystallized after a total time of \(22.8 \mathrm{min}\) is \(0.51\).
|
||
处理第 474/821 条数据...
|
||
处理第 475/821 条数据...
|
||
处理第 476/821 条数据...
|
||
处理第 477/821 条数据...
|
||
处理第 478/821 条数据...
|
||
处理第 479/821 条数据...
|
||
处理第 480/821 条数据...
|
||
处理第 481/821 条数据...
|
||
处理第 482/821 条数据...
|
||
处理第 483/821 条数据...
|
||
处理第 484/821 条数据...
|
||
处理第 485/821 条数据...
|
||
处理第 486/821 条数据...
|
||
处理第 487/821 条数据...
|
||
处理第 488/821 条数据...
|
||
处理第 489/821 条数据...
|
||
处理第 490/821 条数据...
|
||
处理第 491/821 条数据...
|
||
处理第 492/821 条数据...
|
||
处理第 493/821 条数据...
|
||
处理第 494/821 条数据...
|
||
处理第 495/821 条数据...
|
||
处理第 496/821 条数据...
|
||
处理第 497/821 条数据...
|
||
处理第 498/821 条数据...
|
||
处理第 499/821 条数据...
|
||
处理第 500/821 条数据...
|
||
处理第 501/821 条数据...
|
||
处理第 502/821 条数据...
|
||
处理第 503/821 条数据...
|
||
处理第 504/821 条数据...
|
||
处理第 505/821 条数据...
|
||
处理第 506/821 条数据...
|
||
处理第 507/821 条数据...
|
||
处理第 508/821 条数据...
|
||
处理第 509/821 条数据...
|
||
处理第 510/821 条数据...
|
||
处理第 511/821 条数据...
|
||
there are four \(\mathrm{cd}^{2+}\) and four \(\mathrm{s}^{2-}\) ions per unit cell.
|
||
处理第 512/821 条数据...
|
||
the only possible crystal structure for this material is cesium chloride, which has one formula unit per unit cell.
|
||
处理第 513/821 条数据...
|
||
处理第 514/821 条数据...
|
||
处理第 515/821 条数据...
|
||
the fraction of lattice sites that are schottky defects for sodium chloride at its melting temperature is \(4.03 \times 10^{-6}\).
|
||
处理第 516/821 条数据...
|
||
处理第 517/821 条数据...
|
||
处理第 518/821 条数据...
|
||
(a) the composition of the remaining product is \(45.9 \%\) \(\mathrm{al}_{2}\mathrm{o}_{3}\) by weight.
|
||
|
||
(b) the liquidus and solidus temperatures of this material are \(1825^{\circ} \mathrm{c}\) and \(1587^{\circ} \mathrm{c}\), respectively.
|
||
处理第 519/821 条数据...
|
||
处理第 520/821 条数据...
|
||
the ratio of the original and etched crack tip radii is \(21.3\).
|
||
处理第 521/821 条数据...
|
||
the minimum possible radius of the specimen without fracture is \(4.0 \mathrm{~mm}\) (0.16 \(\mathrm{in}\)).
|
||
处理第 522/821 条数据...
|
||
(a) the calculated stress is \(379 \text{ mpa} (53,500 \text{ psi})\), which is less than the flexural strength of \(390 \text{ mpa}\). therefore, fracture is not predicted.
|
||
|
||
(b) the certainty of this prediction is not \(100\%\) because there is always some variability in the flexural strength for ceramic materials. since the calculated stress \(379 \text{ mpa}\) is relatively close to the flexural strength \(390 \text{ mpa}\), there is some chance that fracture will occur.
|
||
处理第 523/821 条数据...
|
||
处理第 524/821 条数据...
|
||
(a) the modulus of elasticity for the nonporous material is \(342 \text{gpa}\) (\(49.6 \times 10^{6} \text{psi}\)).
|
||
|
||
(b) the modulus of elasticity for 10 vol\% porosity is \(280 \text{gpa}\) (\(40.6 \times 10^{6} \text{psi}\)).
|
||
处理第 525/821 条数据...
|
||
(a) the modulus of elasticity for the nonporous material is \(320 \mathrm{gpa}\) (\(46.3 \times 10^{6} \mathrm{psi}\)).
|
||
|
||
(b) the modulus of elasticity will be \(235 \mathrm{gpa}\) (\(34 \times 10^{6} \mathrm{psi}\)) at a porosity of \(15.1 \mathrm{vol}\%\).
|
||
处理第 526/821 条数据...
|
||
处理第 527/821 条数据...
|
||
处理第 528/821 条数据...
|
||
处理第 529/821 条数据...
|
||
处理第 530/821 条数据...
|
||
处理第 531/821 条数据...
|
||
处理第 532/821 条数据...
|
||
处理第 533/821 条数据...
|
||
处理第 534/821 条数据...
|
||
处理第 535/821 条数据...
|
||
处理第 536/821 条数据...
|
||
处理第 537/821 条数据...
|
||
处理第 538/821 条数据...
|
||
处理第 539/821 条数据...
|
||
处理第 540/821 条数据...
|
||
处理第 541/821 条数据...
|
||
处理第 542/821 条数据...
|
||
处理第 543/821 条数据...
|
||
(a) \(62.49 \text{ g/mol}\)
|
||
|
||
(b) \(192.16 \text{ g/mol}\)
|
||
|
||
(c) \(254.27 \text{ g/mol}\)
|
||
|
||
(d) \(74.16 \text{ g/mol}\)
|
||
处理第 544/821 条数据...
|
||
the degree of polymerization is \(23,760\).
|
||
处理第 545/821 条数据...
|
||
(a) the repeat unit molecular weight of polystyrene is \(104.14 \text{ g/mol}\).
|
||
|
||
(b) the number-average molecular weight for a polystyrene with a degree of polymerization of 25,000 is \(2.60 \times 10^6 \text{ g/mol}\).
|
||
处理第 546/821 条数据...
|
||
(a) the concentration of \(\mathrm{cl}\) that must be added is \(20.3 \, \text{wt\%}\).
|
||
|
||
(b) chlorinated polyethylene differs from poly(vinyl chloride) in that, for pvc, (1) \(25 \%\) of the side-bonding sites are substituted with \(\mathrm{cl}\), and (2) the substitution is probably much less random.
|
||
处理第 547/821 条数据...
|
||
处理第 548/821 条数据...
|
||
处理第 549/821 条数据...
|
||
the average number of styrene and butadiene repeat units per molecule is 8530.
|
||
处理第 550/821 条数据...
|
||
the number-average molecular weight of the nitrile rubber copolymer is \(\bar{m}_{n} = 106740 \, \text{g/mol}\).
|
||
处理第 551/821 条数据...
|
||
the other repeat unit in the alternating copolymer is propylene, with a molecular weight of \(42.08 \mathrm{~g/mol}\). this matches the calculated repeat unit weight of \(42.06 \mathrm{~g/mol}\) for the unknown unit.
|
||
|
||
the molecular weights of the other possible repeat units are:
|
||
- ethylene: \(28.05 \mathrm{~g/mol}\)
|
||
- tetrafluoroethylene: \(100.02 \mathrm{~g/mol}\)
|
||
- vinyl chloride: \(62.49 \mathrm{~g/mol}\)
|
||
|
||
thus, propylene is the correct choice.
|
||
处理第 552/821 条数据...
|
||
(a) the ratio of butadiene to styrene repeat units is \(\frac{f_{b}}{f_{s}} = \frac{0.50}{0.50} = 1.0\).
|
||
|
||
(b) the copolymer can be alternating, random, graft, or block. the alternating copolymer requires a 1:1 ratio, which is satisfied here, but the other types (random, graft, and block) are also possible without any ratio restrictions.
|
||
处理第 553/821 条数据...
|
||
the fraction of the ethylene repeat unit is \( f(\text{ethylene}) = 0.69 \).
|
||
|
||
the fraction of the propylene repeat unit is \( f(\text{propylene}) = 0.31 \).
|
||
处理第 554/821 条数据...
|
||
处理第 555/821 条数据...
|
||
处理第 556/821 条数据...
|
||
the diffusion flux is \(1.71 \times 10^{-7} \ \text{cm}^{3}\text{stp}/\text{cm}^{2}-\text{s}\).
|
||
处理第 557/821 条数据...
|
||
the permeability coefficient of ar through hdpe at \(325 \mathrm{~k}\) is \(4.57 \times 10^{-13} \frac{\mathrm{cm}^{3} \mathrm{stp} \cdot \mathrm{cm}}{\mathrm{cm}^{2}-\mathrm{s}-\mathrm{pa}}\).
|
||
处理第 558/821 条数据...
|
||
the diffusion flux is \(5.90 \times 10^{-7} \frac{\text{cm}^{3} \text{stp}}{\text{cm}^{2} \cdot \text{s}}\).
|
||
处理第 559/821 条数据...
|
||
\(e_{\tau}(10) = 4.25 \text{ mpa (616 psi)}\)
|
||
处理第 560/821 条数据...
|
||
处理第 561/821 条数据...
|
||
处理第 562/821 条数据...
|
||
处理第 563/821 条数据...
|
||
处理第 564/821 条数据...
|
||
处理第 565/821 条数据...
|
||
处理第 566/821 条数据...
|
||
处理第 567/821 条数据...
|
||
处理第 568/821 条数据...
|
||
处理第 569/821 条数据...
|
||
处理第 570/821 条数据...
|
||
处理第 571/821 条数据...
|
||
the maximum thermal conductivity \(k_{\max}\) is \(33.3 \mathrm{w/m-k}\).
|
||
|
||
the minimum thermal conductivity \(k_{\min}\) is \(29.7 \mathrm{w/m-k}\).
|
||
处理第 572/821 条数据...
|
||
the upper limit for the specific stiffness of this composite is \(19.0 \text{ gpa}\).
|
||
|
||
an alternate approach yields a specific stiffness of \(17.6 \text{ gpa}\).
|
||
处理第 573/821 条数据...
|
||
处理第 574/821 条数据...
|
||
处理第 575/821 条数据...
|
||
(a) the longitudinal tensile strength is \(1100 \mathrm{mpa}\) (\(160,000 \mathrm{psi}\)).
|
||
|
||
(b) the longitudinal modulus of elasticity is \(41 \mathrm{gpa}\) (\(5.95 \times 10^{6} \mathrm{psi}\)).
|
||
处理第 576/821 条数据...
|
||
the modulus of elasticity of the matrix phase \(e_{m}\) is \(2.79 \mathrm{gpa}\) (\(4.04 \times 10^{5} \mathrm{psi}\)).
|
||
|
||
the modulus of elasticity of the fiber phase \(e_{f}\) is \(70.4 \mathrm{gpa}\) (\(10.2 \times 10^{6} \mathrm{psi}\)).
|
||
处理第 577/821 条数据...
|
||
(a) the required volume fraction of fibers is \(0.393\).
|
||
|
||
(b) the tensile strength of this composite is \(1354 \ \mathrm{mpa}\) (\(196,400 \ \mathrm{psi}\)).
|
||
处理第 578/821 条数据...
|
||
处理第 579/821 条数据...
|
||
处理第 580/821 条数据...
|
||
处理第 581/821 条数据...
|
||
处理第 582/821 条数据...
|
||
(a) the faraday constant \(\mathscr{f}\) is \(96,500 \mathrm{c} / \mathrm{mol}\).
|
||
|
||
(b) at \(25^{\circ} \mathrm{c}(298 \mathrm{~k})\),
|
||
\[
|
||
\frac{r t}{n f} \ln x = \frac{0.0592}{n} \log x
|
||
\]
|
||
this gives units in volts since a volt is a j/c.
|
||
处理第 583/821 条数据...
|
||
a voltage of \(0.0592 \mathrm{v}\) is generated when oxidation occurs in the cell having the \(\mathrm{zn}^{2+}\) concentration of \(10^{-2} m\).
|
||
处理第 584/821 条数据...
|
||
the time of submersion is \(10 \mathrm{yr}\).
|
||
处理第 585/821 条数据...
|
||
the corrosion rate is \(1.2 \mathrm{~mm} / \mathrm{yr}\).
|
||
|
||
the corrosion rate is \(46.7 \mathrm{mpy}\).
|
||
处理第 586/821 条数据...
|
||
处理第 587/821 条数据...
|
||
(a) the rate of corrosion of metal \(m\) is \(2.64 \times 10^{-13}\) mol/cm\(^2\)-s.
|
||
|
||
(b) the corrosion potential for this reaction is \(-0.169\) v.
|
||
处理第 588/821 条数据...
|
||
处理第 589/821 条数据...
|
||
处理第 590/821 条数据...
|
||
处理第 591/821 条数据...
|
||
处理第 592/821 条数据...
|
||
处理第 593/821 条数据...
|
||
处理第 594/821 条数据...
|
||
(a) the electrical conductivity is \(\sigma = 14.9 \, (\omega \cdot \mathrm{m})^{-1}\).
|
||
|
||
(b) the resistance is \(r = 168 \, \omega\).
|
||
处理第 595/821 条数据...
|
||
(a) the drift velocity of electrons in germanium is \(380 \mathrm{~m/s}\).
|
||
|
||
(b) the time required for an electron to traverse a 25-mm length of crystal is \(6.6 \times 10^{-5} \mathrm{~s}\).
|
||
处理第 596/821 条数据...
|
||
(a) the number of free electrons per cubic meter for copper at room temperature is \(1.25 \times 10^{29} \, \text{m}^{-3}\).
|
||
|
||
(b) the number of free electrons per copper atom is 1.48.
|
||
处理第 597/821 条数据...
|
||
the intrinsic carrier concentration for \(\mathrm{pbte}\) at room temperature is \(1.33 \times 10^{22} \mathrm{~m}^{-3}\).
|
||
处理第 598/821 条数据...
|
||
处理第 599/821 条数据...
|
||
处理第 600/821 条数据...
|
||
(a) this germanium material to which has been added \(5 \times 10^{22} \mathrm{~m}^{-3}\) sb atoms is \(n\)-type since \(\mathrm{sb}\) is a donor in ge.
|
||
|
||
(b) the electrical conductivity of this material is \(800 (\omega \cdot \mathrm{m})^{-1}\).
|
||
处理第 601/821 条数据...
|
||
the electron and hole mobilities for \(\mathrm{inp}\) are \(\mu_{e} = 0.50 \, \mathrm{m}^{2}/\mathrm{v}\cdot\mathrm{s}\) and \(\mu_{h} = 0.02 \, \mathrm{m}^{2}/\mathrm{v}\cdot\mathrm{s}\).
|
||
处理第 602/821 条数据...
|
||
the required magnetic field is \(0.58 \mathrm{tesla}\).
|
||
处理第 603/821 条数据...
|
||
处理第 604/821 条数据...
|
||
the mobility for an \(\mathrm{fe}^{2+}\) ion at \(1000^{\circ} \mathrm{c}\) (1273 k) is \(8.64 \times 10^{-11} \mathrm{~m}^{2} / \mathrm{v} \cdot \mathrm{s}\).
|
||
处理第 605/821 条数据...
|
||
the new spacing between the plates must be \(1.6 \mathrm{mm}\).
|
||
处理第 606/821 条数据...
|
||
处理第 607/821 条数据...
|
||
(a) the specific heat at \(50 \mathrm{~k}\) is \(139 \mathrm{~j} / \mathrm{kg}-\mathrm{k}\).
|
||
|
||
(b) the specific heat at \(425 \mathrm{~k}\) is \(923 \mathrm{~j} / \mathrm{kg}-\mathrm{k}\).
|
||
处理第 608/821 条数据...
|
||
处理第 609/821 条数据...
|
||
the linear coefficient of thermal expansion for this material is \(25.0 \times 10^{-6} \, (\degree c)^{-1}\).
|
||
处理第 610/821 条数据...
|
||
处理第 611/821 条数据...
|
||
处理第 612/821 条数据...
|
||
处理第 613/821 条数据...
|
||
处理第 614/821 条数据...
|
||
处理第 615/821 条数据...
|
||
处理第 616/821 条数据...
|
||
2.16 bohr magnetons/atom
|
||
处理第 617/821 条数据...
|
||
处理第 618/821 条数据...
|
||
the number of bohr magnetons associated with each \(y^{3+}\) ion is \(1.75 \, \text{bm}\).
|
||
处理第 619/821 条数据...
|
||
处理第 620/821 条数据...
|
||
the required electric current is \(6 \mathrm{a}\).
|
||
处理第 621/821 条数据...
|
||
the frequency of the photon is \(5 \times 10^{14} \, \text{s}^{-1}\).
|
||
|
||
the energy of the photon is \(3.31 \times 10^{-19} \, \text{j}\) (2.07 ev).
|
||
处理第 622/821 条数据...
|
||
处理第 623/821 条数据...
|
||
处理第 624/821 条数据...
|
||
处理第 625/821 条数据...
|
||
处理第 626/821 条数据...
|
||
处理第 627/821 条数据...
|
||
the reflectivity at the boundary is \(3.87 \times 10^{-5}\).
|
||
处理第 628/821 条数据...
|
||
处理第 629/821 条数据...
|
||
处理第 630/821 条数据...
|
||
处理第 631/821 条数据...
|
||
the average atomic weight of \(\mathrm{zn}\) is \(65.400 \mathrm{amu}\).
|
||
处理第 632/821 条数据...
|
||
the fraction-of-occurrence of \({ }^{113}\)in is 0.043.
|
||
|
||
the fraction-of-occurrence of \({ }^{115}\)in is 0.957.
|
||
处理第 633/821 条数据...
|
||
处理第 634/821 条数据...
|
||
处理第 635/821 条数据...
|
||
处理第 636/821 条数据...
|
||
处理第 637/821 条数据...
|
||
the bonding energy \(e_{0}\) is given by:
|
||
\[
|
||
e_{0}=-\frac{a}{\left(\frac{a}{nb}\right)^{1 /(1-n)}}+\frac{b}{\left(\frac{a}{nb}\right)^{n /(1-n)}}
|
||
\]
|
||
处理第 638/821 条数据...
|
||
处理第 639/821 条数据...
|
||
处理第 640/821 条数据...
|
||
处理第 641/821 条数据...
|
||
处理第 642/821 条数据...
|
||
处理第 643/821 条数据...
|
||
the volume of the unit cell is \(1.213 \times 10^{-28} \mathrm{m}^{3}\).
|
||
处理第 644/821 条数据...
|
||
the radius of a palladium \((pd)\) atom is \(0.138 \mathrm{~nm}\).
|
||
处理第 645/821 条数据...
|
||
the radius of a tantalum (ta) atom is \(0.143 \, \text{nm}\).
|
||
处理第 646/821 条数据...
|
||
(a) the volume of the ti unit cell is \(1.058 \times 10^{-28} \mathrm{~m}^{3}\).
|
||
|
||
(b) the values of \(a\) and \(c\) are \(0.296 \mathrm{~nm}\) and \(0.468 \mathrm{~nm}\), respectively.
|
||
处理第 647/821 条数据...
|
||
(a) the volume of the unit cell is \(1.39 \times 10^{-22} \mathrm{~cm}^{3}\).
|
||
|
||
(b) the values of \(a\) and \(c\) are \(0.321 \mathrm{~nm}\) and \(0.521 \mathrm{~nm}\), respectively.
|
||
处理第 648/821 条数据...
|
||
the atomic packing factor (apf) for uranium is \(0.536\).
|
||
处理第 649/821 条数据...
|
||
(a) 4.0 atoms/unit cell
|
||
|
||
(b) \(7.31 \mathrm{~g/cm}^{3}\)
|
||
处理第 650/821 条数据...
|
||
(a) the unit cell volume for be is \(4.87 \times 10^{-23} \mathrm{~cm}^{3}\).
|
||
|
||
(b) the theoretical density of be is \(1.84 \mathrm{~g/cm}^3\), and the literature value is \(1.85 \mathrm{~g/cm}^{3}\).
|
||
处理第 651/821 条数据...
|
||
the atomic radius for \(\mathrm{mg}\) is \(0.160\;\mathrm{nm}\).
|
||
处理第 652/821 条数据...
|
||
the volume of the unit cell for co is \(6.64 \times 10^{-23} \mathrm{cm}^3\) or \(6.64 \times 10^{-2} \mathrm{nm}^3\).
|
||
处理第 653/821 条数据...
|
||
there are \(8 \mathrm{si}^{4+}\) ions and \(16 \mathrm{o}^{2-}\) ions per \(\mathrm{sio}_{2}\) unit cell.
|
||
处理第 654/821 条数据...
|
||
of the three possible crystal structures, only sodium chloride and zinc blende have four formula units per unit cell, and therefore, are possibilities.
|
||
处理第 655/821 条数据...
|
||
处理第 656/821 条数据...
|
||
处理第 657/821 条数据...
|
||
the degree of polymerization is \(4800\).
|
||
处理第 658/821 条数据...
|
||
(a) the concentration of \(\mathrm{cl}\) that must be added is \(29.0 \text{ wt\%}\).
|
||
|
||
(b) chlorinated polyethylene differs from poly(vinyl chloride) in that, for pvc, (1) \(25 \%\) of the side-bonding sites are substituted with \(\mathrm{cl}\), and (2) the substitution is probably much less random.
|
||
处理第 659/821 条数据...
|
||
处理第 660/821 条数据...
|
||
the average number of acrylonitrile and butadiene repeat units per molecule is 9333.
|
||
处理第 661/821 条数据...
|
||
the number-average molecular weight of the poly(isobutylene-isoprene) copolymer is \(\bar{m}_{n} = 97,700 \mathrm{~g/mol}\).
|
||
处理第 662/821 条数据...
|
||
the other repeat unit is vinyl chloride, with a molecular weight of \(62.49 \mathrm{g/mol}\). this matches the calculated value of \(62.45 \mathrm{g/mol}\) for the unknown repeat unit.
|
||
处理第 663/821 条数据...
|
||
(a) the ratio of butadiene to acrylonitrile repeat units in the copolymer is \( \frac{f_b}{f_a} = 4.0 \).
|
||
|
||
(b) of the possible copolymers, the only one for which there is a restriction on the ratio of repeat unit types is alternating; the ratio must be 1:1. therefore, on the basis of the result in part (a), the possibilities for this copolymer are random, graft, and block.
|
||
处理第 664/821 条数据...
|
||
the fraction of the ethylene repeat unit is \(0.45\).
|
||
|
||
the fraction of the propylene repeat unit is \(0.55\).
|
||
处理第 665/821 条数据...
|
||
处理第 666/821 条数据...
|
||
the fraction of vacancies for this metal at \(900^{\circ} \mathrm{c}\) is \(4.41 \times 10^{-4}\).
|
||
处理第 667/821 条数据...
|
||
(a) the fraction of atom sites that are vacant for copper at \(1357 \mathrm{k}\) is \(4.56 \times 10^{-4}\).
|
||
|
||
(b) the fraction of atom sites that are vacant for copper at \(298 \mathrm{k}\) is \(6.08 \times 10^{-16}\).
|
||
|
||
(c) the ratio of \(\frac{n_{v}}{n}(1357 \mathrm{k})\) to \(\frac{n_{v}}{n}(298 \mathrm{k})\) is \(7.5 \times 10^{11}\).
|
||
处理第 668/821 条数据...
|
||
the number of vacancies per cubic meter in gold at \(900^{\circ} \mathrm{c}\) is \(3.52 \times 10^{24} \mathrm{~m}^{-3}\).
|
||
处理第 669/821 条数据...
|
||
the fraction of lattice sites that are schottky defects for cesium chloride at its melting temperature is \(7.87 \times 10^{-6}\).
|
||
处理第 670/821 条数据...
|
||
处理第 671/821 条数据...
|
||
处理第 672/821 条数据...
|
||
处理第 673/821 条数据...
|
||
处理第 674/821 条数据...
|
||
处理第 675/821 条数据...
|
||
the composition of the alloy is \(87.9 \text{ at}\% \text{ ag}\) and \(12.1 \text{ at}\% \text{ cu}\).
|
||
处理第 676/821 条数据...
|
||
the composition of the alloy is \(3.23 \text{ at\% pb}\) and \(96.77 \text{ at\% sn}\).
|
||
处理第 677/821 条数据...
|
||
the composition in weight percent is:
|
||
|
||
1.68 wt\% cu
|
||
98.32 wt\% pt
|
||
处理第 678/821 条数据...
|
||
the composition, in weight percent, of the alloy is:
|
||
|
||
\(c_{\mathrm{fe}} = 98.87 \, \text{wt}\%\)
|
||
|
||
\(c_{\mathrm{c}} = 0.19 \, \text{wt}\%\)
|
||
|
||
\(c_{\mathrm{cr}} = 0.94 \, \text{wt}\%\)
|
||
处理第 679/821 条数据...
|
||
the composition of the alloy in atom percent is:
|
||
|
||
\( c_{\mathrm{ag}} = 44.8 \, \text{at} \% \)
|
||
|
||
\( c_{\mathrm{au}} = 46.2 \, \text{at} \% \)
|
||
|
||
\( c_{\mathrm{cu}} = 9.0 \, \text{at} \% \)
|
||
处理第 680/821 条数据...
|
||
\(3.30 \times 10^{28}\) atoms/m\(^3\)
|
||
处理第 681/821 条数据...
|
||
the number of atoms per cubic meter in chromium is \(8.33 \times 10^{28} \ \text{atoms/m}^3\).
|
||
处理第 682/821 条数据...
|
||
the concentration of \(\mathrm{si}\) is \(19.6 \mathrm{~kg} / \mathrm{m}^{3}\).
|
||
处理第 683/821 条数据...
|
||
the approximate density of the ti-6al-4v titanium alloy is \(4.38 \mathrm{g/cm}^3\).
|
||
处理第 684/821 条数据...
|
||
the unit cell edge length for an \(80 \mathrm{wt} \% \mathrm{ag}-20 \mathrm{wt} \% \mathrm{pd}\) alloy is \(0.4050 \mathrm{~nm}\).
|
||
处理第 685/821 条数据...
|
||
the crystal structure is simple cubic with \(1.00\) atom per unit cell.
|
||
处理第 686/821 条数据...
|
||
\(1.73 \times 10^{22} \text{ atoms/cm}^3\)
|
||
处理第 687/821 条数据...
|
||
the number of niobium atoms per cubic centimeter is \(1.02 \times 10^{22} \text{atoms/cm}^3\).
|
||
处理第 688/821 条数据...
|
||
the fraction of unit cells that contain carbon atoms is \(9.31 \times 10^{-3}\) atoms/unit cell.
|
||
|
||
there is one carbon atom per 107.5 unit cells.
|
||
处理第 689/821 条数据...
|
||
15.9 wt%
|
||
处理第 690/821 条数据...
|
||
11.7 wt%
|
||
处理第 691/821 条数据...
|
||
(a) 32 grains/in.\(^2\)
|
||
|
||
(b) 320,000 grains/in.\(^2\)
|
||
处理第 692/821 条数据...
|
||
the astm grain size number is \(8.6\).
|
||
处理第 693/821 条数据...
|
||
the astm grain size number is \(4.8\).
|
||
处理第 694/821 条数据...
|
||
处理第 695/821 条数据...
|
||
处理第 696/821 条数据...
|
||
处理第 697/821 条数据...
|
||
the concentration will be \(0.5 \mathrm{kg/m}^{3}\) at a distance of \(2.78 \mathrm{mm}\) from the high-pressure side.
|
||
处理第 698/821 条数据...
|
||
the time necessary to achieve the same concentration at a 6.0-mm position is \(135 \mathrm{h}\).
|
||
处理第 699/821 条数据...
|
||
the temperature at which the diffusion coefficient has a value of \(1.2 \times 10^{-14} \mathrm{m}^{2} / \mathrm{s}\) is \(1427 \mathrm{k}\) or \(1154^{\circ} \mathrm{c}\).
|
||
|
||
alternatively, using the vmse software, the temperature is found to be \(1430 \mathrm{k}\).
|
||
处理第 700/821 条数据...
|
||
the diffusion coefficient at \(1200 \mathrm{~k}\) is \(4.8 \times 10^{-13} \mathrm{~m}^{2} / \mathrm{s}\).
|
||
处理第 701/821 条数据...
|
||
the temperature at which the diffusion flux is \(6.3 \times 10^{-10} \mathrm{kg/m^2 \cdot s}\) is \(884 \mathrm{k}\) or \(611^{\circ} \mathrm{c}\).
|
||
处理第 702/821 条数据...
|
||
the diffusion flux at \(1000^{\circ} \mathrm{c}(1273 \mathrm{~k})\) is \(1.21 \times 10^{-8} \mathrm{~kg} / \mathrm{m}^{2} \cdot \mathrm{s}\).
|
||
处理第 703/821 条数据...
|
||
the position will be \(0.66 \mathrm{~mm}\).
|
||
处理第 704/821 条数据...
|
||
the permeability coefficient at \(325 \mathrm{~k}\) is \(0.73 \times 10^{-13} \frac{\mathrm{cm}^{3} \mathrm{stp} \cdot \mathrm{cm}}{\mathrm{cm}^{2} \cdot \mathrm{s} \cdot \mathrm{pa}}\).
|
||
处理第 705/821 条数据...
|
||
the maximum length of the specimen before deformation is \(0.475 \mathrm{~m}\) (475 mm or 18.7 in.).
|
||
处理第 706/821 条数据...
|
||
the modulus of elasticity of the aluminum is \(71.2 \mathrm{gpa}\) (\(10.4 \times 10^{6} \mathrm{psi}\)).
|
||
处理第 707/821 条数据...
|
||
the elongation of the nickel wire is \(13.8 \mathrm{~mm}\) (0.53 in.).
|
||
处理第 708/821 条数据...
|
||
(a) the maximum load that can be applied without plastic deformation is \(44,850 \mathrm{~n}\) (10,000 \(\mathrm{lb}_f\)).
|
||
|
||
(b) the maximum length to which the specimen can be stretched without causing plastic deformation is \(76.25 \mathrm{~mm}\) (3.01 \(\mathrm{in.}\)).
|
||
处理第 709/821 条数据...
|
||
the diameter must be \(9.5 \text{ mm} (0.376 \text{ in})\).
|
||
处理第 710/821 条数据...
|
||
poisson's ratio for the material is \( v = 0.367 \).
|
||
处理第 711/821 条数据...
|
||
the elastic modulus of the alloy is \(100 \text{ gpa}\).
|
||
处理第 712/821 条数据...
|
||
of the four metal alloys listed, only brass and steel satisfy the stipulated criteria.
|
||
|
||
brass has an elongation of \(1.15 \mathrm{~mm}\), and steel has an elongation of \(0.56 \mathrm{~mm}\), both of which are less than the maximum allowed elongation of \(1.3 \mathrm{~mm}\).
|
||
|
||
aluminum alloy is not a candidate because its elongation of \(1.64 \mathrm{~mm}\) exceeds the limit, and copper is not considered due to its lower yield strength.
|
||
处理第 713/821 条数据...
|
||
the ductility in terms of percent reduction in area is \(60\%\).
|
||
|
||
the ductility in terms of percent elongation is \(46\%\).
|
||
处理第 714/821 条数据...
|
||
the true stress necessary to produce a true plastic strain of 0.21 is \(66,400 \, \text{psi}\) (460 mpa).
|
||
处理第 715/821 条数据...
|
||
the minimum allowable specimen radius is \(9.1 \mathrm{~mm}\) \((0.36 \mathrm{in})\).
|
||
处理第 716/821 条数据...
|
||
the specimen with a square cross section would be expected to fracture at a load of \(17,200 \mathrm{~n}\) (3870 \(\mathrm{lb} f\)).
|
||
处理第 717/821 条数据...
|
||
(a) the flexural stress is \(286.5 \text{ mpa}\). since this value is less than the flexural strength of \(300 \text{ mpa}\), fracture is not predicted.
|
||
|
||
(b) the certainty of this prediction is not \(100\%\) because there is always some variability in the flexural strength for ceramic materials, and the calculated stress is relatively close to the flexural strength, so there is some chance that fracture will occur.
|
||
处理第 718/821 条数据...
|
||
(a) the modulus of elasticity for the nonporous material is \(265 \mathrm{gpa}\) (\(38.6 \times 10^{6} \mathrm{psi}\)).
|
||
|
||
(b) the modulus of elasticity for \(15 \mathrm{vol} \%\) porosity is \(195 \mathrm{gpa}\) (\(28.4 \times 10^{6} \mathrm{psi}\)).
|
||
处理第 719/821 条数据...
|
||
(a) the modulus of elasticity for the nonporous material is \(342 \text{gpa}\) \((49.6 \times 10^6 \text{psi})\).
|
||
|
||
(b) the volume percent porosity at which the modulus of elasticity is \(240 \text{gpa}\) \((35 \times 10^6 \text{psi})\) is \(17.1 \text{vol}\%\).
|
||
处理第 720/821 条数据...
|
||
(a) the flexural strength for a completely nonporous specimen of this material is \(95.3 \, \text{mpa}\).
|
||
|
||
(b) the flexural strength for a 0.20 volume fraction porosity is \(51.5 \, \text{mpa}\).
|
||
处理第 721/821 条数据...
|
||
\(e_{f}(10) = 3.66 \text{mpa} \quad (522 \text{psi})\)
|
||
处理第 722/821 条数据...
|
||
the average hardness value is \(48.4\) hrg.
|
||
|
||
the standard deviation of the hardness values is \(1.95\) hrg.
|
||
处理第 723/821 条数据...
|
||
the average yield strength is \(265.9 \text{ mpa}\).
|
||
|
||
the standard deviation of the yield strength is \(7.34 \text{ mpa}\).
|
||
处理第 724/821 条数据...
|
||
处理第 725/821 条数据...
|
||
the applied stress of \(12 \mathrm{mpa}\) will not cause the single crystal to yield.
|
||
|
||
the necessary stress for yielding to occur is \(15.1 \mathrm{mpa}\) (2200 psi).
|
||
处理第 726/821 条数据...
|
||
(a) the most favored slip direction is at an angle of \(30^{\circ}\) with the tensile axis.
|
||
|
||
(b) the critical resolved shear stress for zinc is \(0.91 \mathrm{mpa}\) (\(130 \mathrm{psi}\)).
|
||
处理第 727/821 条数据...
|
||
the maximum possible yield strength for a single crystal of \(\mathrm{cu}\) pulled in tension is \(\sigma_{y} = 0.96 \mathrm{mpa}\) (140 psi).
|
||
处理第 728/821 条数据...
|
||
the grain diameter at which the lower yield point is \(310 \mathrm{mpa}\) is \(4.34 \times 10^{-3} \mathrm{mm}\).
|
||
处理第 729/821 条数据...
|
||
the deformed rectangular specimen will be harder since it has the greater \(\% \text{cw}\) (24.5\% compared to 22.0\% for the circular specimen).
|
||
处理第 730/821 条数据...
|
||
the critical resolved shear stress \(\tau_{\text{crss}}\) at a dislocation density of \(10^{6} \mathrm{mm}^{-2}\) is \(6.28 \mathrm{mpa}\) (910 \(\mathrm{psi}\)).
|
||
处理第 731/821 条数据...
|
||
处理第 732/821 条数据...
|
||
处理第 733/821 条数据...
|
||
(a) the original grain diameter was \(0.031 \, \text{mm}\).
|
||
|
||
(b) the predicted grain diameter after \(200 \, \text{min}\) at \(650^{\circ} \mathrm{c}\) is \(0.109 \, \text{mm}\).
|
||
处理第 734/821 条数据...
|
||
处理第 735/821 条数据...
|
||
the yield strength of the brass alloy after heating to \(500^{\circ} \mathrm{c}\) for \(1000 \mathrm{~s}\) is \(124 \mathrm{mpa}\) (\(18,000 \mathrm{psi}\)).
|
||
处理第 736/821 条数据...
|
||
处理第 737/821 条数据...
|
||
the estimated tensile strength at a number-average molecular weight of 40,000 g/mol is \(112.5 \text{ mpa}\).
|
||
处理第 738/821 条数据...
|
||
the required number-average molecular weight is \(27,700 \text{ g/mol}\).
|
||
处理第 739/821 条数据...
|
||
处理第 740/821 条数据...
|
||
处理第 741/821 条数据...
|
||
the magnitude of the maximum stress is \(2800 \text{ mpa} (400,000 \text{ psi})\).
|
||
处理第 742/821 条数据...
|
||
the theoretical fracture strength of the material is \(20.7 \mathrm{gpa}\) (\(3 \times 10^{6} \mathrm{psi}\)).
|
||
处理第 743/821 条数据...
|
||
the specimen will not experience fracture because it can tolerate a critical stress of \(1380 \text{ mpa}\) before fracture, which is greater than the applied stress of \(1030 \text{ mpa}\).
|
||
处理第 744/821 条数据...
|
||
fracture will occur since the value \(42.4 \text{mpa} \sqrt{\text{m}}\) is greater than the fracture toughness \(k_{ic}\) of the material, \(40 \text{mpa} \sqrt{\text{m}}\).
|
||
处理第 745/821 条数据...
|
||
the stress level at which fracture will occur for a critical internal crack length of \(6.0 \mathrm{~mm}\) is \(134 \mathrm{mpa} (19,300 \mathrm{psi})\).
|
||
处理第 746/821 条数据...
|
||
the maximum allowable surface crack length without fracture is \(1.08 \mathrm{mm}\).
|
||
处理第 747/821 条数据...
|
||
the minimum length of a surface crack that will lead to fracture is \(0.0182 \text{ m}\) (18.2 mm).
|
||
处理第 748/821 条数据...
|
||
the critical flaw size \(a_c\) is \(16.8 \mathrm{mm}\). therefore, the critical flaw is subject to detection since it exceeds the \(3.0 \mathrm{mm}\) resolution limit.
|
||
处理第 749/821 条数据...
|
||
处理第 750/821 条数据...
|
||
the ratio of the etched and original crack-tip radii is \(8\).
|
||
处理第 751/821 条数据...
|
||
the maximum carbon concentration is \(0.11 \% \mathrm{c}\).
|
||
处理第 752/821 条数据...
|
||
for sn, \(-71^\circ c\) or \(-96^\circ f\).
|
||
for mo, \(776^\circ c\) or \(1429^\circ f\).
|
||
for fe, \(451^\circ c\) or \(845^\circ f\).
|
||
for au, \(262^\circ c\) or \(504^\circ f\).
|
||
for zn, \(4^\circ c\) or \(39^\circ f\).
|
||
for cr, \(586^\circ c\) or \(1087^\circ f\).
|
||
处理第 753/821 条数据...
|
||
the temperature would be approximately \(775^\circ c\).
|
||
处理第 754/821 条数据...
|
||
the stress at which the steady-state creep is \(10^{-5} \mathrm{~h}^{-1}\) is \(59.4 \mathrm{mpa}\).
|
||
处理第 755/821 条数据...
|
||
the steady-state creep rate at \(250^{\circ} \mathrm{c}\) and \(48 \mathrm{mpa}\) is \(1.94 \times 10^{-2} \mathrm{h}^{-1}\).
|
||
处理第 756/821 条数据...
|
||
the steady-state creep rate at \(1300 \mathrm{~k}\) and a stress level of \(83 \mathrm{mpa}\) is \(4.31 \times 10^{-2} \mathrm{~h}^{-1}\).
|
||
处理第 757/821 条数据...
|
||
the critical radius is \(1.10 \text{ nm}\).
|
||
处理第 758/821 条数据...
|
||
the rate of recrystallization at this temperature is \(8.76 \times 10^{-3} \, \text{min}^{-1}\).
|
||
处理第 759/821 条数据...
|
||
the total time required for \(95 \%\) of the austenite to transform to pearlite is \(603 \, \text{s}\).
|
||
处理第 760/821 条数据...
|
||
the fraction recrystallized after a total time of \(116.8 \mathrm{~min}\) is \(0.65\).
|
||
处理第 761/821 条数据...
|
||
处理第 762/821 条数据...
|
||
处理第 763/821 条数据...
|
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处理第 764/821 条数据...
|
||
处理第 765/821 条数据...
|
||
(a) the electrical conductivity of the silicon specimen is \(12.2 \, (\omega \cdot \mathrm{m})^{-1}\).
|
||
|
||
(b) the resistance over the entire specimen length is \(121.4 \, \omega\).
|
||
处理第 766/821 条数据...
|
||
处理第 767/821 条数据...
|
||
处理第 768/821 条数据...
|
||
处理第 769/821 条数据...
|
||
处理第 770/821 条数据...
|
||
(a) the drift velocity of electrons in silicon at room temperature and when the magnitude of the electric field is \(500 \mathrm{v/m}\) is \(72.5 \mathrm{m/s}\).
|
||
|
||
(b) under these circumstances, it takes an electron \(3.45 \times 10^{-4} \mathrm{s}\) to traverse a \(25-\mathrm{mm}\) length of crystal.
|
||
处理第 771/821 条数据...
|
||
(a) the number of free electrons per cubic meter for aluminum at room temperature is \(1.98 \times 10^{29} \, \text{m}^{-3}\).
|
||
|
||
(b) the number of free electrons per aluminum atom is \(3.28 \, \text{electrons/al atom}\).
|
||
处理第 772/821 条数据...
|
||
the intrinsic carrier concentration for \(\mathrm{pbs}\) at room temperature is \(1.95 \times 10^{21} \mathrm{~m}^{-3}\).
|
||
处理第 773/821 条数据...
|
||
the conductivity of the material is \(0.028 \, (\omega \cdot \mathrm{m})^{-1}\).
|
||
处理第 774/821 条数据...
|
||
处理第 775/821 条数据...
|
||
(a) this germanium material to which has been added \(10^{24} \mathrm{~m}^{-3}\) as atoms is \(n\)-type since as is a donor in ge.
|
||
|
||
(b) the conductivity is equal to \(1.60 \times 10^{4} (\omega \cdot \mathrm{m})^{-1}\).
|
||
处理第 776/821 条数据...
|
||
the required magnetic field is \(0.735 \, \text{tesla}\).
|
||
处理第 777/821 条数据...
|
||
the mobility for a \(\mathrm{na}^{+}\) ion at \(600^{\circ} \mathrm{c}\) (873 k) is \(2.34 \times 10^{-13} \mathrm{m}^{2}/\mathrm{v}-\mathrm{s}\).
|
||
处理第 778/821 条数据...
|
||
the new spacing between the plates must be \(3.36 \mathrm{~mm}\).
|
||
处理第 779/821 条数据...
|
||
(a) the capacitance of this capacitor is \(100 \text{ pf}\).
|
||
|
||
(b) the electric field that must be applied is \(2.0 \times 10^{5} \text{ v/m}\).
|
||
处理第 780/821 条数据...
|
||
(a) the dielectric constant \(\varepsilon_{r}\) must be \(5.52\).
|
||
|
||
(b) the dielectric displacement \(d\) will be \(4.89 \times 10^{-6} \, \text{c/m}^{2}\).
|
||
处理第 781/821 条数据...
|
||
处理第 782/821 条数据...
|
||
处理第 783/821 条数据...
|
||
处理第 784/821 条数据...
|
||
处理第 785/821 条数据...
|
||
处理第 786/821 条数据...
|
||
处理第 787/821 条数据...
|
||
处理第 788/821 条数据...
|
||
处理第 789/821 条数据...
|
||
处理第 790/821 条数据...
|
||
处理第 791/821 条数据...
|
||
the maximum thermal conductivity \(k_{\max}\) is \(31.0 \mathrm{~w} / \mathrm{m} \cdot \mathrm{k}\).
|
||
|
||
the minimum thermal conductivity \(k_{\min}\) is \(28.7 \mathrm{~w} / \mathrm{m} \cdot \mathrm{k}\).
|
||
处理第 792/821 条数据...
|
||
the upper limit for the specific stiffness of this composite is \(19.65 \text{ gpa}\).
|
||
|
||
alternatively, the specific stiffness can be estimated as \(18.47 \text{ gpa}\).
|
||
处理第 793/821 条数据...
|
||
the moduli of elasticity of the matrix and fiber phases are:
|
||
|
||
\[
|
||
e_{m} = 2.6 \, \text{gpa} \quad (3.77 \times 10^{5} \, \text{psi})
|
||
\]
|
||
|
||
\[
|
||
e_{f} = 104 \, \text{gpa} \quad (15 \times 10^{6} \, \text{psi})
|
||
\]
|
||
处理第 794/821 条数据...
|
||
(a) the volume fraction of fibers required is \(0.258\).
|
||
|
||
(b) the tensile strength of this composite is \(1070 \, \text{mpa}\) (\(155,000 \, \text{psi}\)).
|
||
处理第 795/821 条数据...
|
||
处理第 796/821 条数据...
|
||
处理第 797/821 条数据...
|
||
(a) the expression for the modulus of elasticity for a hybrid composite with all fibers aligned in the same direction is:
|
||
\[
|
||
e_{cl} = e_m v_m + e_{f1} v_{f1} + e_{f2} v_{f2}
|
||
\]
|
||
|
||
(b) the longitudinal modulus of elasticity of the hybrid composite is:
|
||
\[
|
||
e_{cl} = 59.7 \, \text{gpa} \, (8.67 \times 10^6 \, \text{psi})
|
||
\]
|
||
处理第 798/821 条数据...
|
||
处理第 799/821 条数据...
|
||
a voltage of \(0.0414 \mathrm{v}\) is generated.
|
||
|
||
oxidation occurs in the cell half with the lower \(\mathrm{fe}^{2+}\) concentration (\(2 \times 10^{-2} \mathrm{m}\)).
|
||
处理第 800/821 条数据...
|
||
处理第 801/821 条数据...
|
||
the time of submersion is \(5.27 \mathrm{yr}\).
|
||
处理第 802/821 条数据...
|
||
(a) the rate of corrosion of metal \(m\) is \(3.27 \times 10^{-13}\) mol/cm\(^2\)-s.
|
||
|
||
(b) the corrosion potential for this reaction is \(-0.420\) v.
|
||
处理第 803/821 条数据...
|
||
处理第 804/821 条数据...
|
||
处理第 805/821 条数据...
|
||
(a) the specific heat for copper at \(40 \mathrm{~k}\) is \(47.8 \mathrm{~j} / \mathrm{kg}-\mathrm{k}\).
|
||
|
||
(b) the specific heat for copper at \(400 \mathrm{~k}\) is \(392 \mathrm{~j} / \mathrm{kg}-\mathrm{k}\).
|
||
处理第 806/821 条数据...
|
||
the linear coefficient of thermal expansion for this material is \(15.0 \times 10^{-6} \, ({}^{\circ} \mathrm{c})^{-1}\) \([8.40 \times 10^{-6} \, ({}^{\circ} \mathrm{f})^{-1}]\).
|
||
处理第 807/821 条数据...
|
||
处理第 808/821 条数据...
|
||
处理第 809/821 条数据...
|
||
(a) the magnetic permeability is \(1.260 \times 10^{-6} \, \text{h/m}\).
|
||
|
||
(b) the magnetic susceptibility is \(2.387 \times 10^{-3}\).
|
||
|
||
(c) this material would display both diamagnetic and paramagnetic behavior. all materials are diamagnetic, and since \(\chi_{m}\) is positive and on the order of \(10^{-3}\), there would also be a paramagnetic contribution.
|
||
处理第 810/821 条数据...
|
||
处理第 811/821 条数据...
|
||
1.07 bohr magnetons/cu\(^{2+}\) ion
|
||
处理第 812/821 条数据...
|
||
the number of bohr magnetons associated with each \(\mathrm{sm}^{3+}\) ion is \(2.86\) bm.
|
||
处理第 813/821 条数据...
|
||
the required electric current is \(11.7 \text{ a}\).
|
||
处理第 814/821 条数据...
|
||
处理第 815/821 条数据...
|
||
处理第 816/821 条数据...
|
||
处理第 817/821 条数据...
|
||
the frequency of the photon is \(6 \times 10^{14} \, \text{s}^{-1}\).
|
||
|
||
the energy of the photon is \(3.98 \times 10^{-19} \, \text{j}\) (2.48 ev).
|
||
处理第 818/821 条数据...
|
||
处理第 819/821 条数据...
|
||
处理第 820/821 条数据...
|
||
the reflectivity at the boundary is \(8.45 \times 10^{-6}\).
|
||
处理第 821/821 条数据...
|
||
pure \(\mathrm{znse}\) is transparent to visible light having wavelengths between 0.48 and \(0.7 \mu \mathrm{m}\).
|
||
处理完成，结果已保存到 only_answer.json
|