The processing of data in the University Physies Experiment is particularly crucial.The radius ofcurvature of Newton's rings is measured by interferometry of equal thickness of light as an example : Firstly.different experimental data processing methods were simulated using MATLAB, and the data processing anderror analysis of the three data processing methods of successional difference, least squares and weightedaverage are compared, and the uncertainty of each method is caleulated.lt is found that the least squares method exhibits the optimal fiting results with small errors.Secondly ,the visualization image of Newton's ringsis successfully generated by MA'TLAB, and the experimental results under different wavelengths of light andNewton ring radius are displayed.Comparing the advantages and disadvantages of data processing methods andexperimental visualization can help to intuitively understand and display experimental phenomena and providean effective auxiliary tool for the analysis of experimental results.
Concentration is one of the important parameters of the solution.An on-line measurement system of the solution concentration/refractive index was designed based on the rotating cuvette and Michelson interferometer.Adding the resolution in the cuvette and rotating the cuvette 5°,the number of moving fringes was measured by the intensity curve imaged by CCD and the counting program,and the refractive index and concentration of the solution could be measured,respectively.Taking the NaCl solution with concentration of 0,10% and 20% into consideration,the relative error as compared with the theoretical value is only 0.61%,0.63% and 2.2%,respectively. Meanwhile,the glucose solution curve between the refractive index and concentration presents good linearity and high reliability. The online system measurement of solution concentration/refractive index based on Michelson interferometer has the characteristics of simple design,reliable results,high efficiency and practicality.
The purpose is to discuss the influence of the value of the power supply voltage on the measurement of the internal resistance of the modified meter when the replacement method is used to measure the internal resistance of the meter in the experiment of the meter modification. Through theoretical calculation and experimental research,we found that the essential reason for the increase in measurement error caused by large power supply voltage is that the protection resistance accounts for too high a proportion of the resistance of the whole circuit.The research results of this paper provide an improvement direction for improving the accuracy of resistance measurement by substitution method.
The measurement of gravitational acceleration by a single pendulum is a basic content in the physicsexperiment of the university ,and it is also a conventional method to measure the aeceleration of gravity , in the experiment ,three measurement tools are usually used to measure the period,such as a smart phone ,a multi-funetion timer and 'Tracker software."'he experimental results show that the accuracy of the three measurementtools is in descending order: 'Tracker software , multi-funetion timer, and smart phone. In the experiment , thesingle pendulum period is often affected by the movement of the conic pendulum and produces errors ,and the analysis of Tracker software shows that the movement of the single pendulum will lead to the small gravitation alacceleration of the measured gravity.
In the literature on solar cells , the relationship curve of output current versus output voltage and therelationship curve of output power versus output voltage are generally given. However, it is rare to see therelationship curve of output voltage versus load resistance ,the relationship curve of output current versus loadresistance , and the relationship curve of output power versus load resistanee. These curves are studiedexperimentally and theoretically here.The results of experimental tests and theoretical calculations are quiteeonsistent.Both of them show that , for a determined solar cell circuit, with the increase of load resistanee , theoutput voltage monotonically inereases and the output current monotonically decreases. However, the outputpower does not change monotonically ,there is an optimal power value.'This optimal power value corresponds toan optimal load resistanee value.In addition , we have also studied the impact of incident light intensity on theoutput voltage ,output current and output power of solar cells, and found that all these outputs increase with theinerease of light intensity.The results of this work are of great significance in the design and application of solarcell circuits.
The equivalent cireuit model ( ECM)is an important means to study the complex physical andchemical process of the electrochemical impedance measurement of solution, and it has important application inthe engineering technology research and development of the equipment such as the solution conductivitymeasurement instrument,The potassium chloride solution ( KCl) was selected as the research object , and theimpedanee spectrum of 0.01 mol/l, to 1 mol/L, KCl was measured using electrochemical work station andplatinum black parallel double electrodes, The Lima and Randles ECM were used to fit the measurement resultsrespectively and the accuracy of the two models were compared. Based on the fact that the physical andchemical mechanism of the solution is diflerent at different AC excitation signal frequencies ,the measurementresults are simulated at high and low frequencies respectively, to further improve the simulation accuracy , andthe high-frequeney ECM is raised based on the Lima ECM and Randles ECM. High frequency ECM was used tosimulate the conductivity of KCl solution with different concentrations at high frequeney , and the differences of ohysical and chemical processes in solution caused by different coneentrations were compared and analyzed.
Milligan's oil drop experiment is an important course in university physics experiments. In theexperiment , students study the quantum nature of the microscopic world through macroscopic mechanies , whichcan cultivate students’ hands-on ability , independent learning ability ,ability to comprehensively apply existingknowledge,and ability to organize and coordinate. However, there are problems in teaching such as smalexperimental samples , long experimental procedures, and “ trial and error" selective screening results. lanalyzes the teaching results , discusses the defects in the teaching process, and proposes a plan to improveteaching equipment : using machine vision to improve the process of Millikan's oil drop experiment , real-timeimage processing and automated data collection ,so that students can be more focused on experimental theoryand result analysis , rather than cumbersome operating procedures,Such a system can also make experimentaresults easier to share and discuss, inereasing interactivity , thus improving students' learning motivation andabsorption. lt can not only improve the quality of teaching, but also stimulate students’interest and cultivatetheir scientific literacy and innovation ability,This is an important direction in the development of education altechnology and is worthy of exploration and implementation.
Driven by the “ability to solve complex engineering problems” of engineering education certification,the content and mode of the topic selection of electronic science integrated design course in universities are constantly reformed and innovated.Lithium-ion battery technology is the representative of the current new energy scientific and technological revolution.It has multiple characteristics of interdisciplinary and comprehensive,and meets complex engineering problems. It discusses the feasibility and effectiveness of including lithium-ion battery technology into the comprehensive design course of electronic of science,and
summarizes the specific implementation plan of comprehensive experimental design of lithium-ion battery,which lays a foundation for improving students’ability to solve complex engineering problems and training composite innovative college students.
The characteristic experiment of silicon solar cells is the study of the volt-ampere properties ofsilicon solar cell by means of circuit experiments.Conventional experiments do not fully take into account theelfect of the connection of the measurement apparatus on the measurement results , leading to anomalous datacurves and low elfieiency in practical operational experiments.We present three circuit connection methods forsilicon solar cell load testing and analyze the impact of different meter connection methods on the measurementresults.Students can understand the main points of photovoltaic measurement through the data processinganalysis and discussion of the experimental results. This experiment has cultivated the students ' ability toanalyze and solve problems.
The magnetic domain is the fundamental structure in magnetic materials, which dictates theimagnetic properties. By conducting in-depth investigations into magnetic domains, we can enhanee ourunderstanding of the characteristics of magnetic materials , optimize their performanee, and further advancerelated applications,The Lorentz transmission Electron Microseope( LTEM),as a device based on transmissionelectron microscopy ,enables the observation and analysis of the magnetic domain structures of these materialslts operational principle relies on utilizing the Lorentz force to deflect the electron beam , resulting in patternswith alternating brightness that reflect diferent orientations of magnetic moments within the plane. With itsultrahigh detection sensitivity and nanometer-level resolution , LTEM finds extensive application in studyingmagnetic materials, Introducing L'TEM into undergraduate teaching holds significant importanee as it allowsstudents to gain practical skills and research methods through hands-on experience.Simultaneously ,it cultivatesscientific research literacy and capabilities among students while laying a solid foundation for their future scientific endeavors. Therefore, applying LTEM in undergraduate teaching is not only feasible but also
necessary.