NetWork
Development of an experimental system for superresolution structured illumination microscopy
LI Meiqi;ZHANG Haojia;[Objective] Superresolution microscopy is a key advancement in optical imaging， allowing researchers to visualize biological structures at the nanometer scale. However， integrating it into practical curricula is challenging due to its high cost， operational complexity， and limited flexibility of commercial systems. This work aims to develop a multimodal superresolution fluorescence microscopy platform that is accessible， reconfigurable， and suitable for education and research， addressing the critical need for hands-on training in advanced imaging techniques within undergraduate and graduate programs. [Methods] To balance system integration and modularity， we employed an optical cage system with structural supports featuring through-holes at different heights， enabling a multiaxis three-dimensional (3D) optical design. This design uses standardized cage-compatible optical components with quick-release interfaces to allow rapid switching among various imaging modalities. The system supports four imaging modes: widefield microscopy (WFM)， total internal reflection fluorescence microscopy (TIRFM)， two-dimensional structured illumination microscopy (2D-SIM)， and 3D-SIM. Each mode can be configured by adjusting the illumination path without disassembling the main structure. The platform includes a laser source， a high numerical aperture objective lens， a precision motorized stage， a sensitive complementary metal-oxide-semiconductor camera， and many basic optomechanical components. All control and image reconstruction workflows are implemented in open-source software， allowing customization and algorithm development. Students can perform experiments ranging from fundamental operations (WFM and TIRFM) to advanced functional challenges (2D-SIM and 3D-SIM) within a single system. Performance validation was carried out using various biological samples， including subcellular structures such as actin filaments and fluorescent beads. [Results] Students successfully performed multimodal imaging of subcellular structures， with the system maintaining stability over repeated reconfigurations. The total cost remained below 100，000 RMB， representing an order-of-magnitude reduction compared to commercial alternatives. The superresolution capability was validated through imaging fluorescent bead samples， where adjacent beads that appeared as a single diffraction-limited spot under conventional widefield microscopy were clearly distinguished using SIM. This resolution enhancement directly demonstrates the system’s ability to surpass the diffraction limit. Additionally， the system succeeded in resolving two adjacent actin filaments within a distance less than the optical resolution limit of conventional microscopy. The system also supports potential upgrades of key components for research applications; for instance， when equipped with higher-performance cameras and objectives， the platform can be used effectively for research in cell biology， materials science， and other fields. [Conclusions] We developed a flexible， low-cost， multimodal fluorescence microscopy platform that effectively bridges the gap between theoretical education and practical application in advanced imaging. Its modular design enables seamless switching between imaging modes， providing students with comprehensive training in optical principles and instrumentation while maintaining research capabilities. This integrated approach not only increases access to superresolution techniques but also fosters innovation through hardware and software extensibility. The platform makes incorporating superresolution microscopy into undergraduate curricula easier， with standardized equipment ensuring instructional consistency and better guidance. It also encourages sharing teaching outcomes and provides a solid foundation for students as they transition into scientific research， effectively combining educational development with research preparation in the field of optical microscopy.
Development and application of an intelligent experimental device with series-parallel double towers for absorption and desorption
YING Huijuan;LI Yang;JI Dengxiang;YU Yunliang;YANG Hui;GAO Ling;[Objective] As a core device for teaching experimental chemical engineering principles， absorption and desorption towers are irreplaceable for helping students understand mass transfer theories and master engineering operations. This study addresses the main problems facing traditional experimental absorption and desorption devices， including potential safety hazards caused by the use of toxic gas mixtures such as acetone and ammonia， single-experiment application owing to the single-tower design， low academic value that lags behind the needs of modern industry， and cognitive obstacles resulting from the non-transparency of stainless steel tower bodies. This research aims to develop a new type of multi-functional， intelligent experimental device that supports the training of future engineers capable of addressing complex engineering challenges within the context of emerging engineering education and to provide innovative methods for teaching experimental chemical engineering principles. [Methods] A university-enterprise joint research and development (R&D) model was used to construct a device structure with stainless steel as the frame and transparent organic glass as the tower body. The core design steps include selecting the carbon dioxide–air mixture as the non-toxic and environmentally friendly system to be absorbed， which conforms to green chemical engineering and the “carbon peaking and carbon neutrality” strategy; designing a water circulation system to realize the recycling of water resources and reduce experimental consumption; innovatively building two same-size tower bodies filled with Raschig rings and Pall rings， respectively， which can realize flexible switching between series and parallel connections through valve control; integrating the system with Internet of Things (IoT) and PID intelligent control technology， and matching it with equipment such as infrared detectors and electromagnetic flowmeters to realize part-process touch operation， real-time data display， and remote operation. [Results] The device achieved breakthroughs in multiple dimensions: the transparent tower body resolves the non-transparency problem of traditional devices， enabling visualization of the internal structure and allowing students to observe the gas–liquid flow state; the series-parallel structure facilitates multi-scenario tasks such as parallel measurement of the packing performance and series mass transfer experiments， enriching the teaching content and improving the experimental efficiency; the non-toxic system and intelligent control eliminate potential safety hazards， conform to the characteristics of modern industrial technology， facilitate digital empowerment in experimental teaching， and provide possibilities for cross-regional teaching. This device has been operating stably at Zhejiang University of Technology for three years， with remarkable teaching effectiveness and recognition from certain universities and peers， and has been successfully promoted to six universities. This year， it also became the designated experimental operation device for the National Final and Northwest Division of the 8th National College Students’ Chemical Engineering Experiment Competition. [Conclusions] The intelligent experimental device with series-parallel double towers for absorption and desorption effectively overcomes the limitations of traditional devices. Through visual presentation， multi-process design， safety upgrade， and intelligent control， it helps students deepen the cognitive connection between mass transfer theories and engineering applications， expands the breadth and depth of experimental teaching， and effectively cultivates students’ comprehensive experimental design and data analysis ability， innovative engineering thinking， and ability to solve complex engineering problems. This device provides effective support for reforming the experimental teaching of chemical engineering principles against the background of emerging engineering education and provides a reference for optimizing and upgrading similar teaching equipment.
Process selection and life cycle assessment of waste gas treatment for university laboratories
ZHANG Junjun;ZHONG Ya;[Objective] Volatile organic compounds (VOCs) are key precursors of particulate matter 2.5 and ozone. Although industrial emissions have significantly decreased under the ongoing Blue Sky Protection Campaign， exhaust gases from university laboratories near residential areas have become a critical concern for environmental quality and public health management. University labs typically use many volatile organic and inorganic reagents and feature numerous exhaust-collection points. This results in characteristics such as high total emissions， complex chemical composition， large air volumes， and low concentrations of laboratory exhaust gases. Currently， research on the effectiveness of treatment methods for university laboratory exhaust gases and the assessment of their full life cycle environmental impacts is lacking， limiting evidence-based guidance for selecting appropriate treatment strategies. [Methods] This study focuses on university laboratory exhaust gases and their treatment processes， evaluating treatment efficiency through pilot-scale and bench-scale tests. For bench-scale tests， xylene with varying humidity levels was used as the simulated exhaust gas， while for pilot-scale tests， a mixture of xylene， ethanol， and hydrochloric acid heated in a water bath inside a fume hood served as the simulated exhaust. Three combined treatment processes—“alkali washing + activated carbon adsorption，” “activated carbon adsorption + alkali washing，” and “SDG (acidic exhaust adsorbent) adsorption + activated carbon adsorption”—were examined to thoroughly assess resource and energy consumption and environmental impacts throughout their entire life cycle. [Results] Under dry conditions with an inlet xylene concentration of 400 mg/m3， the saturated adsorption capacity of activated carbon for xylene was 226 mg/g. At 50% relative humidity (RH)， capacity decreased to 114 mg/g， and at 90% RH， it dropped further to 89 mg/g. The “SDG adsorption + activated carbon adsorption” system showed the highest removal efficiency for mixed VOCs (xylene and ethanol)， reaching 83%， along with 91% efficiency for hydrochloric acid mist. Although the “activated carbon adsorption + alkali washing” setup performed slightly lower， both systems significantly outperformed the “alkali wash + activated carbon adsorption” process in VOC removal. This difference is largely due to the high humidity (～100% RH) introduced by front-stage alkali washing， which promotes competitive water vapor adsorption and reduces activated carbon effectiveness. Life cycle assessment indicated that the “SDG adsorption + activated carbon adsorption” method has the lowest overall environmental impact. Additionally， performing alkali washing after adsorption resulted in better environmental outcomes regarding global warming potential and photochemical ozone creation potential compared to front-stage alkali washing. [Conclusions] Environmental impact analysis showed that moving alkaline washing to after the adsorption stage， which increases exhaust humidity， reduced global warming potential by 1.4% and photochemical ozone creation potential by 41.2%. Moreover， replacing wet alkaline washing with dry acidic exhaust adsorbent decreased global warming potential， photochemical ozone creation potential， acidification potential， and human health hazards by 4.5%， 41.3%， 9.9%， and 2.2%， respectively.
Integrated experimental platform for identifying control parameters of doubly fed induction generators based on hardware-in-the-loop impedance testing
ZHANG Xu;WANG Qun;XU Xin;WANG Jiangtao;WANG Jiyu;XIE Yuhan;FANG Xiaoyu;ZHOU Zhimei;XIE Xiaorong;[Objective] This study aims to enhance the teaching quality of electrical engineering courses and address students’ challenges in traditional laboratory instruction， specifically， difficulties in bridging theory with practice and insufficient hands-on experience with cutting-edge engineering problems. It considers two critical industry trends: increasing penetration of doubly fed induction generators (DFIGs) in power systems and the growing prominence of DFIG-related grid stability issues. Commercial wind turbines typically utilize encapsulated controllers with opaque parameters， which pose considerable challenges for power system stability analyses and controller optimization. To tackle these interconnected issues， this paper designs and develops an experimental platform dedicated to the parameter identification of DFIG controllers. [Methods] The platform leverages an improved particle swarm optimization (PSO) algorithm， and its operation is driven by impedance scanning data obtained from a hardware-in-the-loop (HIL) system. First， the study derives an analytical equivalent impedance model for DFIGs that explicitly considers rotor-side converter (RSC) and grid-side converter (GSC) control loops and phase-locked loop coupling effects. Building upon this model， the study establishes a clear mapping relationship between key controller parameters and the system’s frequency-domain impedance response. The model focuses on four critical controller parameters: for the rotor side， the d-axis current loop proportional gain (KP， d， RSC) and integral time constant (TI， d， RSC)， and for the grid side， the d-axis current loop proportional gain (KP， d， GSC) and integral time constant (TI， d， GSC). The core of parameter identification relies on the enhanced PSO algorithm， which employs Latin hypercube sampling combined with Gaussian perturbations for population initialization to effectively enhance population diversity. During the iterative process， the algorithm adopts a dynamic frequency weighting approach， assigning distinct weights to impedance errors across different frequency bands. This weighting prioritizes frequency ranges that are critical for system stability analysis， thereby ensuring more targeted optimization. Concurrently， the algorithm integrates a dynamic parameter management module， which successfully prevents the algorithm from being trapped in local optima by implementing particle perturbations based on boundary expansion and clustering detection. To ensure that the identification results are comprehensive and accurate， the fitness function integrates three key components: impedance magnitude-frequency error， phase-frequency error， and parameter grouping error. The experimental platform， constructed using the OP4510 real-time simulation system and National Instruments data acquisition boards， can perform standard impedance scans and collect high-precision frequency response data. Experimental tests were conducted on three double-fed wind turbines under varying active power output conditions (1.0， 0.5， and 0.1 per unit). For each test condition， the proposed improved PSO parameter identification method was applied to identify the four key controller parameters. [Results] The results indicate that the improved PSO algorithm effectively fits the measured impedance curves， demonstrating strong approximation capabilities. To enhance the reliability of parameter estimates， identification results across multiple operating conditions were weighted and averaged， yielding robust parameter values. These weighted parameters were then substituted back into the DFIG impedance model for validation. This step revealed significant reductions in impedance fitting errors， confirming the effectiveness of the proposed method and its engineering feasibility. Beyond its research applications， the developed experimental platform serves as a cutting-edge engineering practice tool， addressing a notable gap in current experimental teaching protocols for new energy power systems. By employing a visual， hands-on approach， the platform enables students to develop a deeper understanding of the intrinsic relationships between system impedance， controller parameter identification techniques， and system stability. This enriches electrical engineering students’ practical knowledge and holds significant value for cultivating innovative thinking and the ability to solve complex engineering problems. [Conclusions] The methodological framework and experimental validation presented herein provide a concrete contribution to the field of wind turbine controller analysis and pedagogical development in practical engineering education. By synthesizing advanced algorithmic optimization with real-time HIL experimentation， this study establishes a reproducible and effective paradigm to tackle similar black-box identification challenges in modern power electronic systems while serving as an invaluable resource to bridge the gap between theory and industrial practice.
Design of a high-power-density dual-active-bridge converter experimental platform
ZHANG Zhixiong;KUANG Weiyou;QIAN Zhong;TIAN Dawei;HE Dingxin;[Objective] The dual active bridge (DAB) converter has become widely used in power electronics education and research because of its advantages of low current stress， broad soft-switching range， and bidirectional power transfer. However， traditional teaching platforms often face limitations such as visualization of control strategies， high-frequency operational stability， and attainable power density. To overcome these issues， this study develops a digital signal processor (DSP)–based high-power-density DAB converter experimental platform that provides students with a deeper understanding of the DAB topology and its control principles， thereby improving experimental teaching and practical engineering outcomes in power electronics. [Methods] Through theoretical analysis， this study establishes systematic models and waveform derivations for single- and dual-pulse-width modulations (PWMs) combined with phase-shift control strategies. The inductor current expressions under various operating conditions， along with normalized power relationships， are analytically derived. These foundations support the implementation of modulation strategies on the experimental platform. Hardware-wise， the platform integrates the power conversion stage， isolated sensing and gate-drive circuits， and comprehensive protection mechanisms. Silicon carbide (SiC) MOSFETs and a planar transformer are used in the power conversion stage to achieve high-frequency， high-efficiency operation and meet high-power-density requirements. The sensing subsystem employs AMC1302， AMC1311， and Hall-effect sensors to enhance isolation accuracy and noise immunity， while the gate-drive subsystem utilizes the UCC21710QDWQ1 to ensure fast， reliable， and safe switching of SiC devices. The software framework revolves around Texas Instruments’ DSP280039 as the main control unit. The integrated advanced PWM， comparator subsystem， and analog-to-digital converter， along with other peripherals， enable duty-cycle regulation， phase-shift synchronization， overcurrent protection， and real-time system monitoring. Using this setup， a hardware prototype is built and tested under various control strategies to verify voltage and current waveforms. A comparative analysis highlights differences in current stress and energy transfer characteristics across the modulation strategies. [Results] Experimental findings show that PWM plus phase-shift modulation significantly reduces current stress during high-frequency operation. Under traditional single phase-shift control， the measured current stress is about 29.3 A. After applying duty-cycle regulation， the current stress drops to 23.0 A with the single-PWM plus phase-shift technique， and to 23.6 A with the dual-PWM plus phase-shift method. These results confirm that PWM-assisted control effectively optimizes current stress and enhances energy transfer， while also demonstrating the platform’s ability to verify various advanced modulation techniques. The high-power-density DAB platform operates stably at high frequencies， features compact system integration， and shows improved conversion efficiency and thermal performance. Furthermore， its complete sensing， driving， and protection mechanisms provide strong immunity to interference and robust fault response， ensuring reliable operation during laboratory teaching and research. [Conclusions] The DSP280039-based high-power-density DAB converter platform is compact， flexible， well-protected， and capable of stable high-frequency operation. It supports fundamental DAB control strategies and the validation of advanced modulation techniques， offering a solid experimental foundation for understanding energy transfer， modulation principles， and soft-switching characteristics. The platform’s excellent dynamic response and thermal stability make it a valuable platform for future developments in multiloop control， multimode modulation， and high-frequency converter research and education.
Design and application of a direct shear testing apparatus for cylindrical rock specimens
CHENG Xiaobing;ZHANG Zhilong;ZHANG Zhaopeng;ZHANG Ru;LIU Yang;CHEN Hongwei;LI Jianqiang;CAO Zian;[Objective] The ongoing advancements of large-scale water conservancy projects， deep ultralong tunnels， and deep geological storage facilities in geotechnical engineering present severe challenges to the safety of rock mass engineering. The shear strength of rock masses is crucial for engineering construction， as numerous instability incidents stem from shear-failure mechanisms. Therefore， the experimental studies of the shear mechanical properties of rock masses are highly necessary. However， traditional rock shear testing machines are only suitable for square specimens， suffering from uneven stress distribution caused by a rigid contact between the loading indenter and specimen pads. To address this problem， this study optimizes the performance of an existing laboratory rock shear testing machine. The modification simultaneously enables direct shear testing on cylindrical specimens and incorporates acoustic emission monitoring. It also improves the uneven distribution of normal stress on the rock specimens. This optimization is crucial for expanding specimen specifications， enhancing rock shear testing accuracy and scalability， and maintaining the long-term stability of rock engineering structures. [Methods] This study focuses on optimizing the TEST60 rock shear testing machine. The main body of the device comprises an operating box equipped with horizontal load bars on both sides to apply shear loads and a vertical load bar at the top to apply vertical loads. The front end of the horizontal load bar connects to upper and lower pads featuring arc-shaped grooves. These pads are secured via mounting holes and incorporate dedicated holes for acoustic emission sensors. The indenter of the vertical load bar is modified into a spherical shape， and springs are uniformly distributed along its lower edge， connecting to the outer wall of the pressure base to ensure uniform pressure distribution. Using this optimized shear testing machine， shear tests are conducted on cylindrical rock specimens with real-time acoustic emission monitoring. During shear testing， the vertical load rod and spherical indenter are manually lowered. Fine adjustments to the spherical indenter are possible throughout this process to ensure uniform vertical loading. [Results] The shear stress displacement curve exhibits typical prepeak and postpeak mechanical characteristics， effectively illustrating the shear failure mechanism of the specimen. Acoustic emission monitoring reveals minimal activity during the initial loading， followed by a highly active phase after the peak. Combined with the spatial localization of acoustic emissions based on phase segmentation， this clearly reveals the damage evolution mechanism in the specimen， from microcrack initiation to macroscopic fracture. The peak values of the shear stress displacement curve and acoustic emission precisely correlate with the test results， consistent with actual rock mechanical properties. This validates the effectiveness and applicability of the optimized rock shear testing machine. The spherical indenter ensures the uniform distribution of normal stress across the rock specimen， and the concealed acoustic emission sensors enable multimethod collaborative monitoring. [Conclusions] The optimized rock shear testing machine overcomes the limitations of traditional machines， notably their applicability to only square specimens， by incorporating cylindrical pads with holes for acoustic emission sensors， thereby expanding the range of suitable specimen dimensions. The vertical loading head is upgraded to a spherical design， resolving the issues of uneven normal stress distribution and enhancing the accuracy of rock mechanical parameter testing. The optimized direct shear testing apparatus， when combined with techniques such as digital image correlation， enables further investigation into shear failure mechanisms， enabling the execution of a broader range of rock mechanical tests.
Experimental Study on Dynamic Performance of Tunnel Damping Measures Considering Initial Support
QI Bing;XU Haibin;JIANG Chenchen;ZHANG Guangkui;WEI Hong;MA Zhigang;[Objective] Tunnels in high-intensity seismic regions are prone to severe earthquake-induced damage， such as lining cracking， spalling， invert uplift， and progressive plastic deformation， which threaten structural safety and serviceability. Although seismic isolation layers have been widely applied to mitigate tunnel seismic responses， most existing studies focus on the interaction between the secondary lining and isolation layer， while the role of primary support—an essential component in practical tunnel construction—has rarely been explicitly considered. This study aims to clarify the dynamic response characteristics and damage evolution of tunnel linings when seismic mitigation measures are implemented under realistic primary-support conditions. By incorporating primary support into the mitigation system， the effectiveness of a composite “secondary lining-seismic isolation layer-primary support-surrounding rock” configuration is experimentally evaluated， providing guidance for resilience-oriented tunnel seismic design. [Methods] The Jiedexiu No. 2 Tunnel on the Lasa–Linzhi Railway was selected as a representative case， and a series of shaking-table model tests were conducted. A gravity-distorted similarity model was designed based on the Buckingham π theorem， with a geometric similarity ratio of 1:40 and appropriate scaling of elastic modulus， density， displacement， and acceleration. The surrounding rock and overburden were simulated to represent Grade V phyllite and gravelly-breccia soils， respectively. The secondary lining was modeled using gypsum to simulate C30 concrete， while a sponge rubber material was adopted as the seismic isolation layer. Basalt fiber-reinforced polymer anchors were employed to simulate rock bolts in the primary support. Horizontal excitation was applied using the EL Centro earthquake wave with peak ground accelerations of 0.1 g， 0.2 g， 0.3 g， and 0.4 g. Acceleration sensors and strain gauges were symmetrically arranged to compare a conventional section and a mitigated section incorporating the isolation layer and primary support. Dynamic responses were analyzed in both time and frequency domains， including acceleration time histories， Fourier spectra， and acceleration response spectra. To quantify cumulative damage， a Plastic Deformation Index (PDI)， defined as the ratio of residual strain to peak dynamic strain， was introduced to classify damage evolution into elastic， elasto-plastic， and plastic stages. [Results] The results show that the seismic isolation layer significantly reduces the peak amplitudes of acceleration response spectra and Fourier spectra without altering their overall spectral shape. Under low-intensity excitation (0.1 g)， the response spectra exhibit multi-peak characteristics with a predominant period of approximately 0.06 s. With increasing ground-motion intensity， the spectra gradually evolve into a single-peak pattern， accompanied by a lengthening of the predominant period to about 0.08 s， indicating enhanced system nonlinearity and amplification of low-frequency components. Dynamic strain measurements reveal that the mitigated section consistently experiences lower strain peaks and slower strain accumulation， particularly at the crown and invert. In contrast， the haunch exhibits the weakest mitigation effect due to strong boundary constraints. PDI analysis indicates that the conventional section enters a plastic-dominated state when excitation exceeds 0.3 g， whereas the mitigated section remains predominantly in the elasto-plastic stage with substantially lower PDI values. Post-test observations confirm that damage in the mitigated section is markedly reduced compared with the conventional section. [Conclusions] The experimental results demonstrate that a seismic mitigation configuration explicitly considering primary support and incorporating a seismic isolation layer can effectively improve tunnel seismic performance under high-intensity earthquake loading. The composite system reduces spectral amplitudes and plastic deformation demand while preserving the fundamental spectral characteristics of the lining response. The mitigation effect is most pronounced at the invert and crown， whereas the haunch remains a critical zone requiring enhanced design attention. The proposed approach provides a practical experimental basis for energy-dissipation-oriented seismic design and retrofit of tunnels in earthquake-prone regions.
Study on the road performance of basalt fiber reinforced asphalt mixture by test and discrete element simulation
Wu Kun;HE Wanping;Xiong Liwei;Ma Jie;Chen Yu;Huang Xin;Li Changhui;Qi Lin;Sun Bowei;Erwin Oh;Asphalt mixture is a widely used pavement material in road engineering and airport engineering， and fibers can significantly enhance its road performance. However， research on the uniaxial compressive performance of fiber-reinforced asphalt mixtures and the microscopic enhancement mechanism of fibers remains limited. The basalt fiber reinforced asphalt mixture is taken as the research object. The basalt fiber reinforced asphalt mixture material tests， such as Marshall test and uniaxial compressive tests， are carried out to study the effect of basalt fiber content on the physical and mechanical properties of asphalt mixture， such as bulk density， stability， flow value， and compressive strength. Based on the discrete element simulation， a numerical model for basalt fiber reinforced asphalt mixture is established， where the fibers are modeled as clumps， aggregates with diameter larger than 2.36 mm are represented as balls， and the asphalt mortar， composed of aggregates smaller than 2.36 mm and base asphalt， is simulated using a contact model. The discrete element model is verified with the test results and the contact parameters are calibrated. The whole process of crack formation， development and failure of asphalt mixture under uniaxial compression is studied. The results show that (1) With the increase of fiber content， the bulk density and voids filled with asphalt gradually decrease， the void content of asphalt mixture， the optimum asphalt binder content and mineral aggregate voidage of asphalt mixture increase; (2) the incorporation of basalt fibers significantly enhances the mechanical properties of asphalt mixtures， including Marshall stability， flow value， and compressive strength. Compared to asphalt mixtures without fiber， the uniaxial compressive strength increased by 13.2%， 43.3%， and 8.3% at fiber content of 0.2%， 0.3%， and 0.4% by weight， respectively; (3) Fiber content significantly influences the axial compressive performance of asphalt mixtures. The peak value of compressive strength arises at 0.3% fiber content for the asphalt mixtures in the study. When the basalt fiber content is below 0.6%， the compressive strength initially increases then decreases with rising fiber content， yet remains higher than that of mixtures without fiber. Conversely， when fiber content exceeds 0.6%， the compressive strength falls below that of mixtures without fibers; (4) The discrete element model of basalt fiber reinforced asphalt mixtures established accurately simulates the uniaxial compression process. Microstructural analysis reveals that with increasing basalt fiber content， edge fragmentation phenomena and crack propagation in asphalt mixture specimens are significantly reduced， while the number of interparticle contacts markedly increases. Analysis indicates that the discrete element model of asphalt mixtures developed using discrete element modeling software can accurately simulate the internal microscopic mechanisms during uniaxial compression， revealing the influence of basalt fibers on contact evolution and crack propagation within the mixture. Adding an appropriate amount of basalt fibers can enhance the physical and mechanical properties of asphalt mixtures. However， excessive fiber content may lead to fiber aggregation phenomena， resulting in performance degradation. Therefore， for practical engineering applications， the optimal fiber dosage should be determined through experimental testing and theoretical analysis based on specific conditions. The research results have significant reference value for the design of fiber asphalt mixture pavement or airport runway.
Experimental platform for the visual display of the Pockels effect in electro-optic crystals: design and pedagogical application
WENG Yunqi;WU Jiawei;HUANG Yifan;[Objective] The Pockels effect is a foundational principle in the interdisciplinary field of optics and electromagnetism. However， existing experimental methods are incapable of directly measuring the electro-optic phase delay. These methods present several limitations， including dependence on optical power， a high threshold for experimental comprehension， and a disconnect between theoretical principles and concrete cognition. This paper proposes a visualized measurement platform for the Pockels effect that intuitively presents the dynamic variation of electro-optic phase delay under voltage modulation. The platform exhibits core performance characteristics of a wide measurement range and high linearity. The integration of simulation modeling with physical experiments in the teaching process is shown to facilitate the establishment of a concrete correlation between the electric field and phase delay for students. This approach also enhances comprehension of the Pockels effect and improves the quality and efficiency of experimental instruction. [Methods] The visualization platform for measuring the Pockels effect is based on a linear demodulation mode of electro-optic phase delay， implemented through both simulation and experimentation. The specific technical route is as follows. A laser generates linearly polarized light using a polarizer， which then passes through a BGO crystal and a quarter-wave plate. The application of an electric field modulation induces rotation of the polarization plane of the linearly polarized light. The emerging light subsequently passes through an S-wave plate and a polarizer， where the S-wave plate converts linear polarization into radial polarization. When combined with a polarizing filter， the linearly polarized light is transformed into a light and dark gradient ring. The ring rotates in response to changes in the polarization plane angle. Accordingly， real-time detection of the electro-optic phase delay is achieved by observing the rotation of the ring. An image-processing system is proposed to determine the rotation angle of the ring， incorporating image preprocessing， edge detection， and circular positioning. The rotation angle and the corresponding electro-optic phase delay are obtained by plotting the radial gray-value distribution of the ring and calculating the horizontal displacement of the gray-value characteristic curve. [Results] Simulation results show that the proposed measurement system produces a ring spot that rotates with changes in the applied voltage. The electro-optic phase delay angle is found to be twice the rotation angle of the ring. Physical experimental results demonstrate that the system can achieve a dynamic measurement range of 0 to 360° of electro-optic phase delay. The observed phase delay varies linearly with the applied modulation voltage. The measured linearity is 0.47%， with a maximum error not exceeding 1.5%. [Conclusions] This paper provides a comprehensive evaluation of the feasibility of a visual display platform for demonstrating the Pockels effect in electro-optic crystals from three perspectives: theoretical derivation， simulation modeling， and experimental verification. The use of simulation models enhances students’ understanding of the underlying principles of the Pockels effect， while the incorporation of physical experiments strengthens their practical skills. Overall， the platform transforms the abstract principle of the Pockels effect into an intuitive rotation of a light pattern， thereby establishing a direct visual connection between the electric field and phase delay and enabling students to apply theoretical knowledge more effectively.
Research on the Pathways for Universities’ Large-Scale Scientific Facilities to Promote Integrated Development of Education， Science， and Talent
WU Jian;QIU Aici;LI Xingwen;ZANG Zhonghua;Education， science， and talent constitute the foundational and strategic supports for Chinese modernization. Identifying the pathways and mechanisms for their integrated development is essential to achieving high-quality growth. As key components of the national innovation system， large-scale scientific facilities - featuring high investment， sophisticated technology， and long-term operation - play an irreplaceable role in advancing frontier science and fostering talent for national strategic needs. When hosted by universities， these facilities become important platforms for promoting the synergistic development of education， science， and talent. In recent years， Chinese universities have increasingly assumed a leading role in the construction and operation of large scientific facilities. Compared with national research institutes， universities have unique advantages in disciplinary comprehensiveness， human resources， and the integration of research and education. These university-based facilities embed frontier scientific resources into academic training， enabling real-time alignment between teaching and cutting-edge research. They also serve as interdisciplinary hubs， promoting collaboration across physics， materials science， engineering， and information science， thereby contributing to breakthroughs in key scientific and technological frontiers. However， the integration of large scientific facilities within universities still faces multiple challenges. Structurally， universities are constrained by discipline-based administrative systems， resulting in a mismatch between the cross-domain nature of large facilities and the segmented management structure. Institutionally， short-term evaluation mechanisms hinder long-term scientific accumulation， and the insufficient linkage between academia and industry restricts the transformation of research outcomes into educational and technological innovation. Using Xi’an Jiaotong University as a case study， this paper analyzes how institutional innovation can mitigate these challenges. Centering on the construction of the “Electromagnetic-Driven Fusion” large scientific facility， the university established an interdisciplinary framework connecting electrical engineering， plasma physics， nuclear science， and materials disciplines. It developed integrated programs that embed experimental research into curricula， allowing students to engage in the full cycle of scientific practice—from project design and experiment implementation to data analysis and result dissemination. Long-term talent development mechanisms， such as the “Everest Plan” and “Outstanding Undergraduate Program，” were implemented to form a coherent cultivation chain across education levels. Meanwhile， initiatives like “6352” and “1121” promoted deep collaboration among universities， research institutes， and industries， translating scientific progress into educational reform and technological innovation. This study concludes that large scientific facilities in universities are not only key infrastructures for major scientific breakthroughs but also strategic platforms for the coordinated advancement of education， science， and talent. By optimizing organizational structures， improving long-term evaluation systems， and enhancing openness and collaboration， universities can build integrated ecosystems that simultaneously serve national scientific goals and educational innovation， thereby supporting China’s pursuit of high-level scientific self-reliance and educational modernization.