"Physical Properties of Materials" test questions (closed volume A) 1, fill-in-the-blank questions (1 point per space, a total of 30 points): 1, the use of thermal expansion curve to determine the critical point of tissue transformation Usually take two methods are: , 2, list three thermal analysis methods that you know: , , 3, magnetic anisotropy generally includes , , , and so on. 4, thermoelectric effect includes effect, effect, effect, semiconductor refrigeration is the use of effect. 5, the three conditions for the production of nonlinear optical phenomena are , , , . 6, the laser material consists of and , the main role of the former is to provide a suitable lattice field for the latter. 7, piezoelectric functional materials generally use the function, function, function, function or function of piezoelectric material. 8, the calculation formula of elastic specific work when stretching is, from this formula, there are two ways to improve elastic specific work: or, as a vibration damping or energy storage element, it should have elastic specific work. 9. The morphological characteristics of adhesive wear are, and the morphological characteristics of abrasive wear are. 10. Under the condition of constant deformation of the material, with the prolongation of time, the phenomenon of gradual elastic stress is called stress relaxation, and the ability of the material to resist stress relaxation is called . Second, the right and wrong questions (1 point per question, a total of 10 points): 1, the conductivity coefficient reflects the ability of the temperature of the various parts of the material to be consistent in the process of temperature change. ( ) 2, only at high temperatures and the material is transparent and translucent, it is necessary to consider the contribution of photon thermal conductivity. ( ) 3, the atomic magnetic distance is not zero, the necessary condition is the existence of an unfilled layer of electrons. ( ) 4. Both quantum free electron theory and energy band theory believe that the distribution of electrons with energy follows the FD distribution. ( ) 5. Due to the intensification of lattice thermal vibration, the resistivity of metals and semiconductors increases with the increase of temperature. （ ）
6. The DC potential difference meter method and the four-point probe method can measure the resistivity to eliminate the influence of contact resistance. （ ）
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7. Due to the strict correspondence, the emission spectrum of the material is equal to its absorption spectrum. （ ）
8. All ferroelectric bodies must have both piezoelectric effect and pyroelectric effect. （ ）
9. The physical significance of the hardness value depends on the hardness experimental method used. （ ）
10. For high temperature mechanical properties, the so-called temperature level has only relative significance. （ ）
3. Single choice (2 points per question, a total of 20 points):
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1. Regarding the influencing factors of the material's heat capacity, the following statements are incorrect ( )
A Heat capacity is a temperature-dependent physical quantity and therefore needs to be precisely defined by differentiation.
B Experiments have proved that the heat capacity of a compound at high temperatures can be described by Cope's law.
C The Debye heat capacity model has been able to accurately describe the change of material heat capacity with temperature.
The exact relationship between heat capacity and temperature of D materials is generally determined by experiments.
2. Regarding thermal expansion, the following statements are incorrect ( )
A The coefficient of bulk expansion of an isotropic material is three times the coefficient of linear expansion.
B The coefficient of bulk expansion of an anisotropic material is equal to the sum of the coefficients of thermal expansion in the direction of the three crystal axes.
The microscopic mechanism of thermal expansion is due to the expansion of the lattice due to increased temperature and increased density of point defects.
D Since the essence is the same, the thermal expansion and heat capacity have the same tendency with temperature.
3. Among the magnetic properties listed below, the strong magnetism is ( )
A paramagnetism B Ferromagnetism C Antiferromagnetic D Antimagneticity
4. Regarding the factors affecting the ferromagnetism of materials, the following statements are correct ( )
The increase in A temperature reduces MS, BR, and HC. B The temperature increase makes MS and BR decrease, and HC increase.
C Cold plastic deformation makes
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D Cold plastic deformation makes
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5. Which of the following effects is not a semiconductor sensitive effect. （ ）
A Magnetic effect B Thermal effect C Barkhausen effect D pressure sensitive effect
6. Regarding the factors affecting the conductivity of materials, the correct ones in the following statements are ( )
A Due to the increase in scattering due to the increase in lattice vibration, the resistivity of both metals and semiconductors increases with increasing temperature.
B There is no law on the effect of cold plastic deformation on metal resistivity.
C The resistivity of "Thermoplastic deformation + resistivity of annealing state" is higher than that of "thermoplastic deformation + quenching state"
D In general, the resistivity of the solid solution is higher than the resistivity of the components.
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7. Which of the following devices makes use of the pyroelectric function of piezoelectric materials ( )
A electronically controlled flashlock B infrared detector C ferroelectric display device D crystal oscillator
8, the following about ferromagnetism and ferroelectricity, the following statement is not correct is ( )
A is necessary for the existence of a domain structure B is a correction field
C is sufficiently conditioned on the presence of a domain structure D is the presence of a curie point
9. The following hardness experimental methods that do not belong to the static load pressing method are ( )
A Brinell hardness B Shore hardness C Rockwell hardness D Microhardness
10. Regarding the high temperature creep performance, the following statement is incorrect ( )
A The mechanism by which creep occurs is independent of stress levels. B coarse grain is one of the ways to improve the lasting strength of steel.
C Relaxation stability can evaluate the high temperature preload ability of the material. The thermal activation energy of the D creep is related to the chemical composition of the material.
4. Short Answer Questions (6 points per question, a total of 30 points):
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1. Take the Duron-Perti law as an example, and briefly answer the derivation steps of the heat capacity model.
2. How does direct exchange explain the phenomenon of spontaneous magnetization?
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3, what is the Hall effect, briefly answer its application in electrical properties.
4. How to understand the relationship between reflection coefficient and refractive index?
5. Take BaTiO3 crystal as an example, briefly explain the spontaneous polarization caused by thermal motion.
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V. Essay Questions (10 points per question, a total of 10 points):
The technical magnetization process of ferromagnetic materials is divided into several stages, please use a simple diagram to represent and use text to briefly explain the meaning of each stage, indicating how to obtain spontaneous magnetization strength from the diagram.