# 2023知到答案 Math model of metal heating under action by laser beam（1） 最新智慧树满分章节测试答案

## 第一章 单元测试

1、单选题：
Steps at the math modeling are（ ）。

A:Derivation of the conservation laws (integrals of motions) for the problem under consideration.
B:Introducing dimensionless variables and writing similarity parameters (π - parameters).
C:Analysis of the physical and chemical processes occurring in process under consideration.
D:Analysis of physical units of each terms involving in the equations.
E:Developing finite-difference schemes (finite-elements scheme) for numerical solution of the problem under consideration.
F:Quality’s analysis of uniqueness solution or multiplicity of the problem solution. For this aim, as a rule, the pointwise model is derived from PDEs.
G:Writing of the differential (and other) equations describing the process under consideration.

2、单选题：
Which of the following options is the requirement for the numerical method?（ ）。

A:High order of approximation of the differential equations by numerical solution.
B:The numerical method must be tested by using the well-known solutions of the problem under consideration.
C:FDS must be economical one. It means that 3D or 2D difference equations must be solved as sequence of 1D difference equations.
D:All of the above

3、多选题：
The following are applications of laser radiation in the field of physics?（ ）。

A:Optical data storage(CD, SVD, 5D optical memory)
B:Photochemistry
C:Astrophysics
D:Nanophotonics

Astrophysics;
Nanophotonics

4、多选题：
What fields can laser radiation be used in?（ ）。

A:Laser Chemistry
B:Physics
C:LaserMedicine
D:LaserBiology

Physics;
LaserMedicine;
LaserBiology

5、多选题：
What are the properties of laser radiation?（ ）。

A:Stimulated emission.
B:Divergence of laser beam is small.
C:Polarization.
D:Coherence (spatial, temporal).
E:Laser emits monochromatic wave. Usually laser emits single wavelength.

Divergence of laser beam is small.;
Polarization.;
Coherence (spatial, temporal).;
Laser emits monochromatic wave. Usually laser emits single wavelength.

6、单选题：
The one that can explain the experimental curve of blackbody radiation perfectly is （ ）

A:the Riley-Pierce equation
B:Einstein's formula
C:Planck's formula
D:Wien's formula

7、单选题：
A concave cavity with a concave mirror of radius R equal to the cavity length L is a （ ）.

B:Stabilizing cavity
C:Uncertain
D:Critical cavity

8、单选题：
The wavelength of the CO2 laser is（ ）

A:10.6μm
B:1064nm
C:335nm
D:810nm

9、单选题：
The basic structure of the laser consists of electrical working matter, pump source and （ ） three parts.

A:Reflector
B:Affected pole
C:Optical resonant cavity
D:Window mirror

10、单选题：
Carbon dioxide lasers commonly used gas mixture composition is composed of （ ）, helium, argon, nitrogen.

A:Oxygen
B:Carbon monoxide
C:Carbon dioxide
D:Neon gas

## 第二章 单元测试

1、单选题：
What type of laser does the carbon dioxide laser belong to?（ ）

A:Gas laser
B:Solid-state laser
C:Semiconductor laser
D:Fiber laser

2、单选题：
When the pulse energy is certain, the narrower the pulse width, it means the time energy density with time as the denominator （ ）.

A:Uncertain
B:Constant
C:The greater
D:the smaller

3、单选题：
For a uniformly broadened medium, the small-signal gain coefficient at the center center frequency is G0(v0), and when I=Is, saturation is significant, and the non-small-signal center-frequency gain coefficient is: （ ）.

A: B: C: D: 4、单选题：
The following statement about the electric field induction formula is correct （ ）。 A:all
B:P (z,x,y,t ) is polarization of a medium
C:ε (z,x,y,t ) is dielectric permittivity
D:E (z,x,y,t ) is electric field strength

5、单选题：
What is the Duffing’s equation used to calculate electron displacement? （ ）

A: B: C: D: 6、单选题：
The threshold condition is the formation of laser（ ）。

A:sufficient condition.
B:necessary condition.
C:Indeterminate.
D:sufficient necessary condition.

7、单选题：
When a laser propagates from one medium to another with a different refractive index, a (C) will appear at the interface between the media（ ）。

A:Reflections
B:Reflection and refraction
C:Neither
D:Refraction

8、单选题：
The collisional broadening spectral line is（ ）。

A:Lorentzian linear
B:Gaussian line type
C:Parabolic type
D:Hyperbolic type

9、单选题：
Particle number reversal distribution state microscopic particles satisfy （ ）

A:Negative temperature distribution
B:Gaussian distribution
C:Fermi distribution
D:Bormanz distribution

10、单选题：
At a certain temperature, the odds of spontaneous radiation are （ ） times greater than the odds of excited radiation

A: B: C: D: 