In the field of low temperature，cryostat is the most commonly used experimental device to measure the performance of samples at low temperature．Samples often need to carry out basic experiments on electrical，optical，magnetic and thermal properties under the condition of low temperature and constant temperature．It analyzes and explores the concept，composition，classification and structure of cryostat，describes the progress of cryostat，and puts forward the development trend of cryostat in the future．

The influence of a perfect cloaking device on light and the basic principle of geometric optical cloaking are discussed．The feasibility of four-lens cloaking device and the requirements of structural parameters are proved by geometric optical transmission matrix．The optical cloaking performance of the four-lens system is verified by experiments，and the influence of the lens focal length，diameter and object shape on the cloaking effect is discussed．

Based on the traditional falling ball method to measure the liquid viscosity coefficient，combined with Millikan oil drop experiment，the oil drop in the air is simulated as a small ball moving in the liquid，so that the idea of measuring the liquid viscosity coefficient by falling ball method can be applied to the measurement of air viscosity coefficient．The CCD imaging system is used to capture the state of oil droplets and use intelligent phones to record their movement process．The“ Tracker ”software is used to collect relevant physical quantities，and finally the air viscosity coefficient is calculated．

Using FB805-type rotating liquid experimental instrument，a simple measuring method is designed to explore the law of refractive index of laser light in the same medium changing with temperature．This method can intuitively and real-time obtain the refractive index of liquid at different temperatures，and then obtain the relationship between temperature and refractive index(temperature range is 27．5 ℃ to 80 ℃)．Through the experimental operation，experimental data collection and processing and error analysis．it will provides ideas for the improvement and further exploration of the instrument．

When a certain wavelength of light passes through the liquid，some of the light intensity will be absorbed by the liquid，and the absorption ability of different concentrations of liquid to the light intensity will be different．The remaining light intensity after liquid absorption will still cause photocurrent to be generated in the phototube．Based on the experimental principle of photoelectric effect，the corresponding photocurrent of the same liquid at different concentrations was measured．The calibration curve of the two is drawn，and the linear equation of the two is fitted by computer．That is，the corresponding concentration of the liquid can be calculated only by measuring the photocurrent of the liquid after light blocking through the photoelectric effect tester．

With alcohol solution，NaCl solution and sucrose solution as research objects and Michelson interferometer as carrier，the relationship between refractive index and concentration of these solutions at 20 ℃ was studied by titration．By fitting the variable relationship between the concentration and the refractive index， the functional relationship n(c)of the refractive index n with the concentration c is obtained by integral operation，and then the refractive index of the solution at any concentration is given．This experiment can not only be used as a design experiment or an extension experiment of college physics to cultivate students’ practical ability and innovative ability，but also can be used to measure the refractive index of solutions at different concentrations．It would have a good prospect in application．

In order to study the influence of the positions of KTiOPO 4 (KTP)crystal in the cavity for the output power of green laser，the inquiry experiments of intracavity and extra cavity frequency doubling green light with Laser Diodes(LD)pumped solid－state laser experiment instrument were designed．The relationship of the frequency doubling efficiency of green light，the power density and the spot radius of the fundamental frequency beam were analyzed． When KTP was at different positions of intracavity and extracavity，output powers of 532 nm frequency doubled green light were measured，respectively．In the experiment of extracavity frequency doubling，two experimental schemes were designed，namely，KTP was at different positions of extra cavity which whether or not have lens．By guiding students to calculate corresponding beam radius of 1 064 nm fundamental frequency light with the theory of cavity and gaussian beam，the reason for the difference of 3532 nm frequency doubling output power of KTP crystal at different positions，and the method of improving frequency doubling efficiency through improving laser power density with lens focusing were analyzed．

Porous silicon carbide ceramics with high porosity were prepared at low temperature by using ternary system Al 2 O 3 -Y 2 O 3 -SiO 2 as sintering aids of SiC powder，graphene，starch and flake graphite as pore forming agents．The effects of pore forming agents on the bulk density，porosity and bending strength of porous silicon carbide ceramics were discussed．The phase composition and microstructure of porous silicon carbide ceramics were analyzed．The results show that:(1)The pore forming effect of graphene in this system is better than that of starch and flake graphite，and the bending strength of porous SiC ceramics with graphene as pore forming agent is higher than that of porous SiC ceramics with flake graphite as pore forming agent，and lower than that of porous SiC ceramics with starch as pore forming agent．(2)Porous SiC ceramics sintered with different pore forming agents at 1 400 ℃ have a porosity of 53．34%～56．82% and a flexural strength of 14．86～17．47 MPa． (3)The use of different pore forming agents did not change the phase composition of silicon carbide ceramics．

The experiment is based on the improved Jolly’s scale，and a device for measuring stiffness coefficient using Hooke’s law is designed by using the principle of optical lever．The device obtains the rotation angle of the lever by recording the distance between the initial and final positions of light movement，calculates the extension length of the measured spring．The experiment overcomes the influence of the deadweight of the spring，reduces the measurement error，makes the experimental phenomenon more intuitive，and enhances the experimental measurement accuracy．

With the continuous development of China’s construction industry and the continuous adjustment of energy structure，the photovoltaic curtain wall using new energy has achieved initial results in energy conservation and emission reduction，but when the photovoltaic system works，there is still a rise in the temperature of the back plate of the photovoltaic panel and affect its work efficiency，which in turn leads to the problem of increased energy consumption． Therefore，it proposes a new type of energy-saving and environmentally friendly air-cavity structure photovoltaic curtain wall，on the one hand，to study the influence of the external surface of the wall and the air cavity between the photovoltaic backsheet on the heat dissipation efficiency．On the other hand，the principle of Seebeck effect is used to study the relationship between heat absorption and the efficiency of photovoltaic panels by the copper－constantan thermocouple thermoelectric conversion device on the back of photovoltaic panels．Finally，through the analysis of the experimental data，it is concluded that the heat dissipation efficiency of the photovoltaic building wall based on the Seebeck effect increases with the increase of the width of the air cavity，and the utilization of the heat of the photovoltaic backsheet by thermocouples can promote the improvement of the efficiency of the photovoltaic panel．

The traditional method can effectively improve the magnification，but additional devices are needed to determine the reflection times．Through the combination of a large plane mirror placed in a slant to the mirror of the optical lever，the number of reflections is accurately controlled to 2 levels，and the optical path is increased while an angle change is increased．Finally，the magnification is increased to 4 times of the traditional lever method．Theoretical analysis and experimental results show that the oblique double mirror method is used to measure the Young’s modulus of metal wire． The experimental results are in good agreement with the theoretical analysis，which verifies the effectiveness of the method and theory．In addition，the amplification factor is as high as 84．36 times in the limited space not more than 80 cm．

The influence of the grating on the spectrometer table which rotated a certain angle on the change of diffraction angle is analgzed theoretically，and through the Matlab software to make surface chart which can visually observe the change of diffraction angle as you increase the rotation angle and the diffraction angle． Compared the experimental measurements with theoretical derivation，found that the grating rotated a certain angle，the change of diffraction angle used in the calculation increases with the increase of the diffraction angle，and it will cause some errors in the calculation of wavelength．

In order to cultivate innovative talents，a research experiment of “preparation and interface effect study of van der Waals heterostructure”was designed．The two-dimensional heterostructure MoS 2 /WTe 2 was prepared by dry transfer method． The heterostructure was characterized by Ｒaman spectroscopy． Photoluminescence spectroscopy was utilized to explore the coupling effect and mechanism of the heterostructure interface． Integrating scientific research with experiment teaching increases the interest and exploration of the experimental content，which is beneficial to enhance students’comprehensive practical ability，innovative thinking，and teamwork consciousness．

It takes the experimental project“Growth and Physical Properties Characterization of Solid Material Samples”as an example to explore the introduction of experimental content combining basic knowledge and cutting-edge research content into undergraduate experimental teaching，and to carry out research-based experimental courses．The development of such courses will provide undergraduates with the opportunity to know frontier research，cultivate students’scientific literacy，help student establish awareness of breaking through scientific problems，improve students’ability to solve comprehensive and complex problems，and help student adapt to the rapid development of society．It presents the whole process of scientific research from the investigation and selection of SrPd 2 Ge 2 superconducting materials，to the single crystal sample growth，crystal structure measurements and electrical transport measurements of SrPd 2 Ge 2 ．

Ｒainbow and secondary rainbow are magical natural phenomena in the atmosphere． In order to visually observe the rainbow and secondary rainbow and explore their optical phenomena and influencing factors，we designed two demonstration devices for reproducing the rainbow and secondary rainbow，which can reproduce the phenomenon of the rainbow and secondary rainbow at the same time，measure the observation position and the incidence of the rainbow and secondary rainbow．The angle of light，explore the reasons and conditions of the formation of rainbow and secondary rainbow phenomenon． Through the observation and analysis of the rainbow and secondary rainbow produced by transparent glass balls with different diameters，it is indirectly proved that the larger the raindrop，the more significant the rainbow and secondary rainbow phenomenon，and the exit angle of the rainbow and secondary rainbow has nothing to do with the diameter of the water drop．The rainbow and secondary rainbow demonstration device has simple operation，clear phenomenon and low cost．It is very suitable to extend to classrooms or science and technology museums to help understand the rainbow phenomenon and its optical principles．

The traditional stroboscopic photography experiments are usually carried out in a dark room with strict environment requirements．It designs and develops a mono-pendulum stroboscopic photography system based on USB camera，which can be used in bright classrooms conveniently and efficiently．The motion of mono- pendulum is captured by USB camera in real time，then the relative position of the ball is acquired by inter-frame difference method and the stroboscopic photograph is generated by one click to display the motion track of the ball，and the period of the ball is calculated by Fourier transform．Experimental results show that the system can meet the requirements of experimental teaching well with high accuracy and intuitive demonstration．

The non-invasive nature of ultrasonic flow-meters is prominent among many flow-meters．It does not need to destroy the internal structure of the pipe to know the liquid condition inside the pipe．The ultrasonic “V-shaped”time difference method is used to measure the condition of the liquid inside the pipeline，and the multiple pulse method is used to achieve the demand of high precision．The 52 single-chip microcomputer is used to carry out micro control and calculation，and the relevant results are displayed by LCD display screen． The device can be used to measure the liquid flow rate and flow direction change in non-transparent pipes．

The core of random numbers is the unpredictability and non-repeatability of numbers．It is a key issue in the field of cryptography research and an important guarantee for information security．Based on the randomness of Brownian motion，a device for generating random numbers is designed and fabricated．The device is mainly used as a source for generating random numbers by tracking the trajectory changes of particles doing Brownian motion．using the experimental device to sample 537 sets of data to analyze the generation of random numbers，it is found that the probability of the generated decimal random numbers is basically equal，and the maximum error is only 0．017，which can meet the needs of unpredictability and non-repeatability of true random numbers．

In view of the disadvantages of the viscosity coefficient measurement experiment by the falling ball method:it is difficult to ensure that the ball is released from the center，and the manual timing error is large， the viscosity coefficient measuring instrument is improved．With the help of the automatic lifting ball release device，it is convenient to adjust the initial position of the ball and ensure that the ball is released from the center of the liquid surface;the metal detector can monitor the falling displacement of the ball in real time．The design of the sealing plate and the discharge pipe can achieve the collection effect of the liquid． The experimental results show that the measured value of viscosity coefficient by the modified device has less error，higher reliability and more accurate experimental results．

The experimental instrument and method for measuring thermal conductivity of materials were introduced in this work．The instrument，which is based on the steady-state plate principle，uses electric energy and solar energy as dual energy sources to measure the thermal conductivity of various materials such as metals，nonmetals，liquids，and gases etc．The experimental instrument has the characteristics of rail plug-in structure，stable，safe，easy to operate，wide measurement content，accurate measurement data，and can be used in scientific research and physics experimental teaching field．

A method of determining the material of prism by using simple optical experimental instrument is proposed．Taking sodium lamp as light source and using spectrometer to measure the minimum deflection angle，the types of prisms can be distinguished，however the material of prism cannot be determined．Taking mercury lamp as the light source，because the chromatic light will produce dispersion phenomenon after being refracted by the prism，the refractive index can be calculated by using the spectrometer to measure the minimum deflection angle，and the dispersion curve can be obtained． After fitting the dispersion curve with different dispersion formulas and comparing it with the standard dispersion curve of common materials in the same band，the glass composition of the prism can be determined． This method of practical significance is economical，simple，and accurate．

In the current literature，the planar transmitting coil and planar receiving coil are mostly used in the market to achieve magnetic coupling resonant radio energy transmission，but the disadvantage is that the transmission efficiency is not high．To solve this problem，a new concave transmitting coil was designed and made.The magnetic field distribution was measured by fluxgate sensor．The results show that the magnetic field distribution of the concave transmitting coil is more convergent to the central axis than that of the planar transmitting coil．The experimental circuit was set up for comparison experiment．The results show that for the same planar receiving coil，the transmission efficiency of the concave transmitting coil is significantly improved by 10% compared with that of the planar transmitting coil．

LabVIEW language is used to combine the magnetic field acquisition device and the motion control platform to develop a system that can automatically scan and reproduce magnetic fields in real time.The system includes a three-dimensional motion platform，a multi-channel Gauss meter，and host computer software．The collected data is stored in the file in real time，and is displayed in real time on the control interface in various forms such as graphs，two-dimensional intensity maps，three-dimensional vector arrow charts，etc．，to help users understand the magnetic field information in time． Finally，the external magnetic field distribution of the cylindrical magnet array used in the magnetic levitation experiment was actually measured using this system，and the external magnetic field distribution characteristics of the magnet array were clearly displayed，which proved the feasibility and reliability of the system．

In order to improve college students’ information literacy and practical ability，based on Mathstudio，the application of Mathstudio in data processing of three thermal experiments is introduced．Meanwhile，the processing results are compared with those of other data processing software，demonstrating the feasibility，necessity，efficiency and convenience of using Mathstudio to improve students’ability of data processing and analysing．The thermal experiment data processing method based on Mathstudio presented in this paper enriches the application of smart phones in physics experiment data processing，which is of great significance for accelerating the research and practice of teaching informatization reform and enhancing the deep integration of students’information literacy and practical ability．

The factors of Michelson interference are briefly analysed when the moving mirror and the fixed mirror are not perpendicular，and a simulation platform for the Michelson interference based on MATLAB GUI is designed．By observing the changes of the interference pattern with the influence parameters when the two mirrors are not perpendicular，it is expected to help students deepen their understanding of the Michelson interference phenomenon，enhance their interest in learning，and improve teaching efficiency．

The effective processing and analysis of experimental data by using scientific software is one of the goals for the teaching of“College Physics Experiment”．Taking Newton’s ring experiment as an example，we introduce that the use of Igor Pro can efficiently complete the processing of experimental data，the data collection and the data analysis of experimental images，which is of great benefit to cultivating students’ scientific literacy and innovation ability．Moreover，it can also lay a good foundation for students’follow-up course study．In addition，due to the current epidemic，the importance of online experimental courses has become more and more prominent．using variable program software，such as Igor Pro，can better show the key points of College Physics Experiment and improve the effect of online learning．

The significance of the undergraduate physics experiment competition and the basic situation of the 8th china undergraduate physics experiment competition are introduced．It focuses on how to maximize the role of undergraduate physics experiment competition in the cultivation of innovative talents．The exploration paths of improving the status of college physics experiments in teaching，strengthening the construction of experimental teachers，strengthening the exchanges of various science and engineering disciplines，and promoting university- industry collaborative education program．

“Curriculum ideological and political education” is an important measure for colleges and universities to realize the fundamental task of values establishment and people cultivation． College physics experiment course is a good carrier of “curriculum ideological and political education”．The infiltration of ideological and political education into the teaching of college physics experiment course can make the ideological and political education contained in college physics experiments present vividly in the minds of students，which is favour of cultivating the students’scientific literacy．In order to find an effective way to combine curriculum teaching with ideological and political teaching，the overall teaching design of “college

physics experiment”for“Ideological and Political Course”has been carried out．Taking Newton’s ring as an example，how to integrate the ideological and political elements of the course into all aspects of college physics

experiment teaching has been discussed，in addition，student evaluation and teaching summary are given．

“Curriculum design of lithium-ion battery”is an important practical course for the major of new energy materials and devices．It is set up to cooperate with“lithium-ion battery principle and structure”．Based on the curriculum training goal of“curriculum design of lithium-ion battery”，it analyzes the current situation of curriculum design，and then proposes a construction scheme of the staged training system．The curriculum design is divided into three stages:preparation，learning，practice and achievement display，the students’ learning enthusiasm，innovation ability，ability to apply theory to practice and teamwork ability are comprehensively improved．Finally，the effect of teaching reform are consolidated and further improved through

the evaluation system reform and after-class feedback，and the experience is offered to practical engineering courses．

In view of the practicality of the college physics experiment course，according to the professional characteristics of our university and relying on the current college physics experiment content，an online open course is established to comprehensively solve the students’learning problems in the three main links of preview before class，classroom experiment operation and experiment report after class，break through the traditional experimental teaching mode，actively explore the hybrid teaching mode combining online and offline，and improve the teaching effect of college physics experiment course for science and engineering students in our university．

In order to fully implement the party’s educational policy in the new era，according to the basic requirements of national higher education personnel training，the ideological and political work of College Physics Experiment course has been carried out． On the premise of understanding the basic spirit and requirements of the documents of the Ministry of Education，we have formed a correct understanding of ideological and political work in the curriculum，defined the connotation requirements of ideological and political work in College Physics Experiment，and established the implementation strategies of ideological and political work in the curriculum，namely，etting the curriculum ideological and political goal，establishing the principles of ideological and political construction，clarifying the path of ideological and political construction and designing the implementation plan．After one year’s construction and practice，some achievements have been made and valuable practical experience has been accumulated．

The resource advandge of physics experiment laboratory was further developed by introducing scientific research training experiment projects，set up extracurricular experimental exploration groups and organizing various discipline competitions．The teaching content was enriched and a exploration and innovation practice environment for students to integrate inside and outside class was created．It improved the interest and challenge of the physics experiment course，and effectively promoted the reform of physics experiment teaching and the cultivation of top-notch talents．

Under the drive of engineering education professional certification，the teaching reform of college physics is imperative．It analyzes the current teaching situation of college physics，through revising the teaching programme，stimulating students’interest in learning，changing teaching methods，and cultivating students’ autonomous learning ability，in order to meet the requirements of engineering education professional certification for the engineering students．