This paper presents an experiment based on the optical fiber Fabry-Perot (F-P)interferenceprinciple．A high-precision weak-pressure measurement system was designed and constructed． The systemconsists of a spring-based pressure-deformation module，an F-P optical fiber displacement measurementmodule，and an algorithmic processing system based on a PC-end LabVIEW platform． The displacementmeasurement module calculates the cavity length variation by demodulating the wavelength difference betweenadjacent valleys in the interference spectrum．Spring’s elastic coefficient is then derived from the applied massof calibration weights．This calibrated coefficient enables the system to measure the mass of arbitrarily smallobjects．Experimental results indicate that the system exhibits good linearity within the 0 ～ 500 mg range．For
objects heavier than 20 mg，the maximum measurement error is approximately 5%，and the error decreases as
the mass increases．The proposed system features a simple structure，low cost，and high measurement accuracy，
offering a feasible optical method for high-precision weak-pressure measurement．

This study developed an experimental methodology for measuring convective heat transfercoefficients using infrared thermography．The experiment employed 6061 aluminium alloy specimens，with high-emissivity black adhesive tape applied to the surface to mitigate infrared temperature measurement errors．By integrating steady-state and unsteady-state temperature field measurement techniques，the convective heat transfer coefficients under three flow conditions—natural convection (no wind)，forced convection (1．5 m/s，and 2．5 m/s wind speeds)—were quantitatively analysed． The experimental results demonstrated that:1)Surface treatment effect:The black adhesive tape increased surface emissivity from 0．856 to 0．987，significantly improving the measurement accuracy of the infrared thermal imager;2)Convective intensity influence:The convective heat transfer coefficient increased markedly with forced convection strength． Under natural convection，1．5 m/s，and 2．5 m/s wind speeds，the coefficients were 17．67 W/(m 2 ·K)，20．69 W/(m 2 ·K)，107．65 W/(m 2 ·K)，respectively，aligning with Newton＇s law of cooling．This experimental framework provides
an intuitive and advanced observational tool for heat transfer education．Through systematic analysis of heat
transfer mechanisms and engineering problem-solving，students gain a deeper understanding of convective heat
transfer principles，strengthen the application of theoretical knowledge to practical engineering scenarios，and
enhance their scientific research literacy and innovation capabilities．

The efficient use of solar photovoltaic power generation is of great significance to the realization of
the " dual carbon" goal in the future，and this paper proposes an experimental scheme to reduce the
temperature of photovoltaic cells by using a spray cooling system with pressure-swirl atomizers as the main
body，so as to improve the power generation performance of photovoltaic cells．A set of spray-cooled photovoltaic
cell test benches was built to explore the effects of nozzles on spray cone angle，flow rate，droplet size and
velocity under different pore sizes and pressures，and the spray characteristics of the nozzles were clarified．The
spray cooling technology is used to cool the photovoltaic cells，improve the efficiency of power generation，and
reduce the net cost of photovoltaic power generation． This comprehensive experiment creates a practical
application platform，which effectively helps students enhance their understanding of fluid mechanics，heat
transfer and photovoltaic cell thermal management，and promotes the construction of disciplines．

The traditional method for measuring the linear expansion of metals usually involves using an FD-
LEA type linear expansion coefficient tester in combination with a dial indicator．However，due to the fact that
the response rate of the instrument to temperature is higher than that of the dial indicator to deformation，the
measurement results have relatively large errors． This experiment improved the traditional instrument by
replacing the dial indicator with a self-built Michelson interference device and conducted measurements based
on the principle of optical interference．After the improvement the relative error score of the linear expansion
coefficient of the copper rod decreased from 10．77% to 4．61%，and accordingly the uncertainty also decreased
from 0．41 × 10－6℃－1 to 0．18 × 10－6℃－1，achieving a significant improvement in measurement accuracy． In
addition，the surface of the copper rods was ground and polished in this experiment，further reducing the
relative measurement error to 1．20%．The above experimental results show that the use of optical interferometry
can significantly improve the measurement accuracy of the linear expansion coefficient of metals，and at the
same time，surface treatment can eliminate the negative impact of surface oxidation of metal rods． This
experiment not only presents a highly precise device for measuring the linear expansion coefficient of metals，
but also provides a useful reference for its high-precision measurement．

A new scheme for measuring liquid density based on the electric field force effect of parallel plate
capacitors is proposed．By theoretically analyzing the phenomenon of the liquid level rising under the action of
electric field force when the capacitor is partially immersed in the liquid，the quantitative relationship between
the liquid density and the liquid level equilibrium height is derived．The method uses the virtual work principle
to establish the relationship between the electric field force and the energy change of the system，and realizes
the indirect measurement of liquid density through electrical parameters．This method has unique advantages in
specific application scenarios，especially in non-contact density measurement of high-purity or highly corrosive
insulating liquids，and provides a new technical idea for liquid density measurement．

A three-dimensional automated magnetic field measurement experimental device was developed
based on the Hall effect．Its 3D Hall probe can simultaneously measure the three-dimensional components of
magnetic flux density at any spatial position．Different 3D spatial magnetic field distributions can be generated
by adjusting the center-to-center distance of the Helmholtz coils and the excitation current，and one-key
automated 3D magnetic field distribution measurement can be realized．Experimentally，the magnitude of the
magnetic flux density at the center of the Helmholtz coils under different excitation currents was measured，
verifying its linear relationship with the excitation current，and the relative error between the experimentally
measured average value and the theoretically calculated value was calculated．The distribution laws of the three-
dimensional magnetic flux density along different axes in various regions between the Helmholtz coils were
further investigated，providing experimental support for an in-depth understanding of the magnetic field
distribution of Helmholtz coils．

To address issues such as hysteresis errors and complex operation in traditional magnetic field
measurement based on magnetically induced rotation angle，an improved magnetic field measurement method
based on the Faraday magneto-optical effect is proposed．This method realizes the measurement of magnetic
induction intensity by utilizing the power change of light passing through a magneto-optical crystal under the
action of a magnetic field． In the experiment，a magnetic field measurement device based on magnetically
induced optical power variation was constructed using a laser，polarizer，magneto-optical crystal，and optical
power meter．The relationship between the magnetic field and the optical power of light passing through the
magneto-optical crystal was analyzed theoretically．Additionally，measurements of the internal magnetic field of a
solenoid and error analysis were conducted．When the excitation voltages were 1．5，3．0 and 4．5 V respectively，
the measured magnetic induction intensities inside the solenoid were 0．727，1．372，and 2．068 mT．The relative
errors compared with the actual values were 2．1%，2．4% and 1．8% respectively，and the total combined
uncertainties were 0．230，0．216 and 0．161 mT respectively．Compared with other magnetic field measurement
methods based on the magneto-optical effect，this method offers the advantages of small error，simple optical
path structure，and easy operation．

Lead sulfide colloidal quantum dots have emerged as a significant research focus in short-wave
infrared (SWIＲ)detection due to their tunable bandgaps and solution-processing advantages． However，
professional experimental teaching frequently faces challenges such as a lack of cutting-edge content and
fragmented practical training modules．Leveraging the research group＇s established expertise，this paper presents
a comprehensive，full-process experimental project spanning from material synthesis to device architecture and
terminal imaging applications．Central to this design is a two-step passivation strategy，which guides students to
comparatively explore the impact of different ligand exchange processes on surface defects and the resulting
photoelectric performance of SWIＲ detectors． The results demonstrate that the two-step passivated devices
achieve an external quantum efficiency exceeding 40% at 1 350 nm and facilitate successful perspective fusion
imaging of objects concealed within opaque capsules．By bridging abstract semiconductor physics with hands-on
device fabrication，this project utilizes visualized imaging to stimulate student engagement，effectively enhancing
their engineering proficiency and innovative capacity．

A method for measuring weak magnetic fields using the Lissajous figure technique was proposed，and
a relationship between magnetic field intensity and frequency was derived．A homemade weak magnetic field
measurement device was designed and fabricated，comprising a TGG magnetic field sensing system，a
transimpedance amplification and acquisition system，a signal " voltage-frequency" conversion system，and a
frequency measurement system．The transimpedance amplification and acquisition system amplified the signal
by a factor of 10 11 ．The experimental instrument achieved a measurement resolution of 10 Hz，with a minimum
measurable magnetic field strength of 11 μT and a measurement error of less than 3 μT，which decreases as the
measured magnetic field intensity increases．The instrument can accurately measure the Earth＇s magnetic field
and eliminate its influence in other magnetic field measurements．Finally，the error conditions of the homemade
instrument system were analyzed．

It is well known that there is a tunneling effect in quantum mechanics．A particle can pass through
regions where its energy is lower than potential energy．In such a barrier region，the kinetic energy of the
particle is negative．The calculated transmission coefficient of the one-dimensional square barrier in quantum
mechanics textbooks have not yet been quantitatively verified experimentally．According to previous theoretical
analysis，in the barrier region，particles should follow the Schrdinger equation for negative kinetic energy，and
the expression of the negative kinetic energy of a particle is the usual expression of positive kinetic energy plus
a negative sign．In the barrier region，the momentum of the particle is still real rather than imaginary． We
propose an experimental scheme in which photons collide electrons in the barrier region to determine whether
the momenta of the electrons with negative kinetic energies in the barrier region are imaginary or real．

By knowing the electron charge，calculate the standard uncertainty of the charge and its relationship
with the falling time and equilibrium voltage to determine the optimal measurement interval． Based on
experimental data from 6637 Millikan oil droplet experiments and simulated data generated by random
numbers，this study systematically analyzes the errors in Millikan oil droplet experiments and identifies issues to
be aware of in experimental teaching．

This work designed a new experimental scheme to study the chaotic phenomenon of ink droplet
diffusion in water．The experiment captured a video of ink droplet diffusion and measured the motion status and
trajectory of ink droplets in water by tracking them．By observing and recording the time and distance intervals
of ink ring grading during ink droplet diffusion in water，and combining the chaos constant calculation model，
the chaotic phenomenon of ink droplets in water was analyzed，and with the help of Tracker software，the ability
to track a single point can be used to track the trajectory of a specific ink droplet and construct a mathematical
model of the ink droplet trajectory．Finally，calculate the specific value of the chaotic constant and compare it
with existing chaotic constant values．

Liquid crystal，as a special state of matter between liquid and crystal，has extensive applications in
fields such as display technology due to its electro-optic effect．The experiment on the electro-optic effect of
liquid crystals is an important part of university physics experiments，which can help students deeply
understand the physical properties of liquid crystals and the mechanism of electro-optic conversion．This paper
takes TN-type liquid crystal as the research object，measures the electro-optic data of liquid crystal
corresponding to the different positions of the analyzer，and obtains the changes of threshold voltage，saturation
voltage，contrast and slope with the position of the analyzer by drawing the electro-optic curve．It provides a
practical reference for the teaching and research of liquid crystal-related knowledge and is conducive to
cultivating students＇ scientific inquiry ability．

In response to the urgent need for three-dimensional measurement of weak magnetic fields，this
study presents the design and development of a three-dimensional weak magnetic field measurement device
based on the Hall effect．The instrument integrates the high-precision BMM150 magnetic sensor and VL6180
distance sensor，combined with a spatial positioning module and signal processing circuitry，enabling precise
and real-time measurement of weak magnetic field vectors in three-dimensional space．Through bidirectional
iteration of theoretical modeling and experimental calibration，the sensitivity and stability of the sensor have
been significantly enhanced．The test results indicate that the device achieves a measurement range of ±1300 μT
for the x and y axes，and ±2047 μT for the z axis．The results of this study not only provide a portable and cost-
effective solution for weak magnetic field measurement，but also offer robust technical support and an
experimental platform for related teaching and research activities． Future work will further broaden the
application scenarios and functionalities．

To address issues such as cumbersome operation and limited experimental variables in traditional
illuminance teaching experiments，an integrated illuminance characteristic research instrument was designed．
This device consists of a light source module，detection module，signal processing and display module，and
power supply module．It supports independent control of key variables such as light source distance，power，and
wavelength，enabling comparative experiments to verify the impact patterns of single variables on illuminance．
The experimental results align with theoretical predictions．Teaching practice demonstrates that this instrument
is easy to operate，significantly enhances experimental teaching efficiency，and effectively fosters undergraduate
students＇ scientific inquiry skills and innovative thinking．

To solve the low precision，poor stability and complex operation of traditional setups，this study
designs a novel string vibration device based on Ampere force drive and the standing wave method．By replacing
mechanical vibration sources with electromagnetic drive and integrating high-precision tension sensors and
automatic data acquisition systems，the device realizes continuous tension adjustment，wide-range frequency
control and accurate force-positioning．Experiments verify the quantitative relationships between string vibration
frequency and tension square root，string length reciprocal as well as linear density reciprocal square root，with
low-frequency fundamental frequency and wave velocity errors generally ＜1% and high-frequency resonance
recognition errors controlled within 2% via SPL burst criteria and spectrum analysis． With a user-friendly
interactive interface，the device is suitable for university physics teaching and provides an extensible platform
for engineering vibration analysis．

Introducing simulation systems into physics laboratory teaching can overcome the limitations of
traditional experiments in terms of time，space，and equipment，improve experimental efficiency，help students
deepen their understanding of principles，and enhance the quality of teaching． This study addresses the
pedagogical requirements for understanding Fraunhofer diffraction and creates a MATLAB GUI-based
integrated simulation training software that incorporates phenomenon simulation，parameter manipulation，and
theoretical explanations．The curriculum focuses on diffraction theory and develops physical models for single-
slit，circular aperture，and rectangular aperture (diffraction grating)diffraction．Users can modify parameters
such as incoming wavelength，aperture size，and lens focal length in real time via an interactive interface while
presenting the curves of diffraction intensity distribution and multi-dimensional patterns． It facilitates
demonstrations of both monochromatic and white-light diffraction．The program provides still images and moving
graphics that clearly explain diffraction phenomena and how different factors affect them，helping students grasp
difficult physical ideas and encouraging their interest in science．

A virtual simulation platform for Bragg grating spectral characteristics was established based on MATLAB，employing a computational model combining the transfer matrix method and coupled-mode theory to systematically investigate the effects of parameters including chirp，grating length，modulation depth，and apodization type on reflection spectra．Simulation results demonstrate that when chirp increases from 0 nm/cm to 1．0 nm/cm，the 3 dB bandwidth of the reflection spectrum expands from 0．80 nm to 2．60 nm，representing abroadening ratio of 3．25 times．When grating length increases from 1 mm to 15 mm，peak reflectivity rises from25% to 100%，with bandwidth narrowing from 1．60 nm to 0．50 nm．As modulation depth increases from 2．0×10－4 to 2．0×10－3，peak reflectivity improves from 40% to 100%，while bandwidth extends from 0．15 nm to 1．25 nm．Apodization analysis reveals that hyperbolic tangent apodization optimizes sidelobe levels from －14 dB in uniform gratings to －32 dB． The simulation program achieves spectral calculation，depth reflection distribution，and energy accumulation visualization，quantitatively revealing that the front 30% of the grating contributes over 60% of reflection energy，with the maximum reflection rate gradient occurring at the initial section．This platform exhibits high computational accuracy and clear physical mechanisms，providing robust
technical support for Bragg grating design optimization and experimental teaching．

Fourier-domain mode-locked (FDML) lasers，a novel laser technology，exhibit unique time-
frequency characteristics． This paper presents a comprehensive overview of the principles，research
applications，and pedagogical implementations of FDML lasers．Specifically，through classroom instruction and
hands-on experiments，educators leverage FDML lasers as an integrated experimental platform to facilitate
students’in-depth understanding of core concepts，including mode-locking mechanisms and resonant cavity
design．The study further analyzes the technology’s advantages in fostering students’innovative thinking and
practical skills． Incorporating FDML lasers into teaching not only enhances instructional quality but also
promotes the deep integration of scientific research and pedagogy，offering novel insights for the training of
optical engineering professionals．

Under the guidance of the "ideological and political education in courses" concept，natural science
courses need to organically integrate ideological and political education into the entire teaching process．This
paper takes the " Millikan Oil-Drop Experiment" in college physics experiments as the research object，and
systematically explores the ideological and political elements contained in the experimental teaching process
and their integration paths．By constructing an ideological and political education model combining the pre-
experiment，in-experiment and post-experiment stages，the organic unity of knowledge impartment，ability
cultivation and value guidance is realized．The research shows that by deeply exploring the scientific spirit，
humanistic care and value paradigm in the experimental content，the educational effect of physics experiment
courses can be effectively improved．At the same time，corresponding countermeasures are proposed for the
possible challenges in the practice process，providing references for the ideological and political construction of
similar experimental courses．