NetWork
Construction and photocatalytic tetracycline degradation performance of a bismuth vanadate–copper oxide heterojunction
DANG Mingming;[Objective] To address the high carrier recombination rate and low degradation efficiency of traditional single-component photocatalysts， this study aims to construct efficient bismuth vanadate–copper oxide (BiVO4–CuO) heterojunction photocatalysts and investigate their performance in tetracycline degradation. [Methods] BiVO4–CuO heterojunction photocatalysts with different component ratios were prepared via a hydrothermal method and characterized using various analytical techniques to analyze their structural properties. The photocatalytic performance was evaluated using tetracycline as the target pollutant under visible light irradiation (λ > 420 nm). The degradation mechanism was elucidated through kinetic analysis， active species trapping experiments， and electrochemical measurements. The effects of reaction temperature， pH， catalyst dosage， and initial tetracycline concentration on degradation efficiency were systematically investigated. [Results] The experimental results showed that 1) X-ray diffraction and high-resolution transmission electron microscopy confirmed the successful construction of a heterojunction structure with intimate contact between BiVO4(121) and CuO(-111) facets; 2) under optimal conditions (catalyst dosage of 0.5 g/L; tetracycline concentration of 20 mg/L; pH 7.0)， the BC-1 sample achieved an apparent rate constant of 0.021 6 min-1， with 90.3% degradation and 85.6% mineralization rates within 120 min; 3) Mott–Schottky and X-ray photoelectron spectroscopy analyses verified the formation of a Z-scheme band structure favorable for carrier migration， extending the carrier lifetime to 15.6 ns; 4) electron spin resonance and electrochemical tests revealed ·O2- and ·OH as the primary active species， achieving degradation through C—N and amide bond cleavage; 5) after five cycles， the catalyst maintained 91.8% of its initial activity. [Conclusions] Through facet control and interface engineering， an efficient BiVO4–CuO heterojunction photocatalyst was successfully constructed. The Z-scheme band structure significantly enhanced the separation efficiency of photogenerated carriers， achieving effective degradation and mineralization of tetracycline. This work provides valuable insights for the development of high-performance composite photocatalytic materials.
Analysis of the Degradation of Safety Barriers and Organizational Reliability for University Laboratories under the Bowtie-HRO Integrated Model
Yang Fuqiang;Li Ao;Huang Zonghou;Zhang Hong;[Objective] University laboratories are the core base for talent cultivation and scientific and technological innovation， and their inherent safety level directly impacts the high-quality development of higher education. With the expansion of laboratory scale and the increasing complexity of experiments， traditional management models focusing on static hardware compliance checks are insufficient to address the systemic degradation of safety barrier systems caused by organizational vulnerabilities. This study aims to construct a Bowtie-HRO integrated analysis framework to systematically identify the evolution paths of laboratory accidents and analyze the degradation factors of safety barriers from the perspective of organizational reliability. The research findings will provide scientific methodological support for building a highly resilient laboratory safety system， ensuring the long-term safety and stability of the research environment.[Methods] This study adopts a structured multi-stage integrated analysis framework. First， the Bowtie model is used to construct a visualized "threat-barrier-consequence" risk path for laboratory accidents. This model is based on statistical analysis of 176 typical domestic laboratory accident cases， ensuring the objectivity of risk identification data. Second， the 4M1E theory (Man， Machine， Material， Method， Environment) is introduced as an analytical dimension to scan the potential degradation factors of the 19 key safety barriers identified in the dynamic operating environment. Finally， High Reliability Organization (HRO) theory is introduced to map the degradation factors to the five characteristics of HRO (preoccupation with failure， reluctance to simplify interpretations， sensitivity to operations， commitment to resilience， and deference to expertise)， diagnosing system-level organizational reliability failure points， and formulating corresponding countermeasures.[Results] The research results based on the Bowtie-HRO model show: 1) Risk statistical characteristics: The main safety threats in university laboratories originate from hazardous chemicals (62.5%) and equipment failures (21.59%)， with fires (47.73%) and explosions (30.68%) being the most serious types of accidents. 2) Barrier effectiveness diagnosis: The 19 key safety barriers identified in the study (such as centralized procurement of hazardous chemicals and emergency drills) show a tendency towards dynamic degradation due to personnel violations and management deficiencies. 3) Organizational attribution analysis: The HRO mapping confirms that technical-level barrier failures can often be traced back to organizational defects. For example， delayed information transmission reflects the lack of the "preoccupation with failure" principle， while the perfunctory implementation of dual-person， dual-lock management exposes serious deficiencies in the "deference to expertise" dimension. 4) Case Study and Empirical Review: Through the reconstruction of typical explosion accidents， it was verified that the failure of multiple barriers can be traced back to specific organizational reliability deficiencies， including the use of non-explosion-proof equipment， lack of prior risk assessment， and unauthorized changes to experimental procedures. [Conclusions] The integration of the Bowtie and HRO models constructs a closed-loop management framework for laboratory safety， achieving a shift in safety focus from "static compliance" to "dynamic organizational reliability building." To prevent barrier degradation， the study proposes five safeguard strategies based on HRO characteristics: establishing a deviation reporting and learning mechanism to capture accident precursors; conducting multi-dimensional risk analysis to avoid oversimplification of risk interpretation; implementing real-time monitoring based on sensing technology to enhance operational sensitivity; improving system resilience through redundant design and scenario-based drills; and empowering frontline professionals to ensure that professional judgment guides technical decisions. These measures can ensure that critical barriers remain stable in complex environments， comprehensively improving the safety level of university laboratories.
Experimental system for airtightness testing based on computer vision
FAN Zheyi;TIAN Hongdong;WANG Chenyang;XIAO Muzheng;[Objective] Airtightness， the ability of a product to prevent gas leakage， is a critical performance indicator for high-performance equipment in industries such as aerospace， shipping， and chemical engineering. During the manufacturing process， airtightness testing of key components is essential. The liquid application method is widely used in batch manufacturing due to its low cost and operational simplicity. Traditional manual inspection， although a common method， is highly subjective， difficult to quantify， and inefficient. It also carries a high risk of missed or incorrect judgments due to inspector fatigue. To address these limitations， this study proposes a quantitative airtightness testing system based on the liquid application method and computer vision technology to transition from manual observation to objective， automated detection. [Methods] The proposed system， developed using the PyQt5 framework， integrates image acquisition， parameter configuration， camera calibration， intelligent soap-bubble detection， bubble size measurement， and result visualization. It runs on a platform equipped with a GTX1050Ti graphics card and supports up to six cameras simultaneously for comprehensive multi-view surface coverage. For accurate physical measurement， a camera calibration method using standard spheres is employed. By placing 5 mm standard spheres on the product surface， the system applies Canny edge detection and Hough circle transform to extract sphere contours and compute local pixel-to-millimeter ratios. To compensate for surface curvature and lens distortion， a cubic spline interpolation algorithm is used to establish a global mapping across the detection area. For bubble detection and segmentation， particularly for bubbles with irregular shapes， varying sizes， and complex backgrounds， a lightweight YOLOv11 instance segmentation network is adopted. A dataset of more than 1，200 images collected from real experimental environments is constructed for training. Through transfer learning and iterative optimization， model parameters are reduced to approximately 40% of the standard version while maintaining high detection accuracy. Following segmentation， the maximum chord length method calculates the equivalent diameter of each bubble， avoiding inaccuracies associated with traditional equivalent circle assumptions. [Results] Experimental validation was conducted on real product components with known airtightness defects. A total of 627 images were collected from six viewing angles. The system demonstrates stable detection and tracking of soap-bubble generation and evolution. It achieves a detection accuracy of 95.3% for bubbles exceeding a predefined threshold， with average and maximum measurement errors of 0.19 mm and 0.3 mm， respectively. The optimized YOLOv11 model maintained high segmentation accuracy while achieving an inference speed of over 15 frames/s. The multi-camera configuration and calibration method ensure reliable measurement consistency across the detection area， effectively supporting quantitative leakage analysis. [Conclusions] The proposed system transforms the traditional subjective soap-bubble inspection method into an objective， quantitative， and automated approach for airtightness testing. By integrating multi-camera imaging， precise calibration， deep learning-based bubble segmentation， and the maximum chord length method， the system substantially improves detection reliability.
The Evaluation Model for the Utilization Efficiency of Valuable Instruments and Equipment in Universities
LIU Yanqiang;HE Pan;WANG Tianrui;YAN Bing;WANG Yimin;[Objective] The issue of utilization efficiency of valuable instruments and equipment in universities has become an important research topic in the field of higher education governance in recent years， attracting high attention from all sectors of society and universities themselves. A scientific and reasonable assessment and evaluation system plays a crucial role in effectively evaluating and improving the utilization efficiency of valuable instruments and equipment. Given the equivalent relationship between investment cost and utilization efficiency， this study aims to construct a dynamic evaluation standard system model based on equipment value， providing an operable quantitative framework for the performance governance of valuable instruments in universities. [Methods] The principle of cost-benefit equivalence is introduced into the evaluation of utilization efficiency of valuable instruments and equipment， which means that the higher the equipment value， the greater the expected efficiency， and vice versa. Based on the statistical data of laboratory information from local universities， ten evaluation indicators are selected as specific research objects， including unit price， operating hours， sample testing， trained personnel， teaching experiment projects， scientific research projects， social service projects， awards， patents， and papers. SPSS software is used to conduct correlation analysis on the evaluation indicators to identify the correlations between them. For the evaluation indicators with large correlation coefficients， SPSS software is used for curve fitting to find the intrinsic functional relationship between the relevant indicators. The CRITIC objective weighting method is introduced to assign weights to the evaluation indicators. An evaluation system is constructed， and its applicability and effectiveness in practical management scenarios are verified through empirical application. [Results] SPSS software is used to analyze the correlations among the evaluation indicators， and nine relationships are selected， including unit price and operating hours， social service projects and unit price， patents and papers， operating hours and papers， scientific research projects and social service projects， sample testing and operating hours， awards and unit price， trained personnel and awards， and teaching experiment projects and awards. The relationship models between the evaluation indicators are identified， and a dynamic assessment and evaluation system with equipment value as the core is constructed. Based on the statistical data of laboratory information from local universities， three universities are selected as sample cases for empirical analysis， and the evaluation results of the sample universities are obtained. According to the evaluation results， the analysis is conducted from five aspects: the comprehensive scores of valuable instruments and equipment in the sample universities， significant differences in the comprehensive scores of valuable instruments and equipment in different price ranges， significant price threshold effects of valuable instruments and equipment， the advantages and disadvantages of internal evaluation indicators in universities， and differences in performance evaluation models for different types of valuable instruments and equipment. [Conclusions] The dynamic evaluation system for valuable instruments and equipment based on equipment value proposed in this paper has certain practical application value， which is mainly reflected in deriving a generation mechanism for indicator benchmark values， promoting the matching of equipment value with efficiency， forming an automatic output mechanism for evaluation results， and facilitating universities in improving their open-sharing mechanisms. This evaluation system provides a useful reference for further improving the equipment performance assessment mechanism and enhancing the level of asset and equipment management in universities.
Comprehensive experimental design for the effects of asymmetric rolling on the microstructure and properties of pure tantalum
HAN Zhenhua;PANG Hailong;MENG Qingnan;LIU Gang;TANG Yufei;[Objective] Tantalum (Ta) is a refractory metal with a body-centered cubic crystal structure. It exhibits outstanding physical and chemical properties， including a high melting point， high density， excellent ductility， superior corrosion resistance， and favorable biocompatibility. In recent years， it has been widely applied in the aerospace， chemical engineering， and medical device industries， and is a common sputtering target in the electronics industry. Ta targets are typically fabricated by plastic deformation followed by annealing of high-purity Ta ingots. A fine and uniform grain structure， together with a preferred crystallographic orientation， is critical for achieving high sputtering efficiency and improved film uniformity. However， due to inherent microstructural inhomogeneities in the initial ingot and nonuniform plastic deformation during processing， obtaining a refined and homogeneous microstructure—especially one with consistent crystallographic texture—remains a substantial challenge using conventional processing techniques. To address this issue， this study systematically investigates the influence of various rolling processes on the microstructure of high-purity Ta and proposes a novel processing strategy that integrates asymmetric rolling (AR) with subsequent recrystallization treatment. [Methods] High-purity Ta ingots are prepared by vacuum arc-melting in a Ti-gettered argon atmosphere. The ingots are processed by AR for a total thickness reduction of 90%， achieved by setting the speed ratio of the top and bottom rollers to 1.2∶1. To ensure homogeneous deformation， samples are rotated 135° in the normal direction and flipped between consecutive rolling passes. For comparison， synchronous rolling (SR) is also conducted under the same total reduction， with the upper and lower rolls operating at a speed ratio of 1∶1. The rolled specimens are then annealed at 1 000 ℃， 1 100 ℃， and 1 200 ℃ for 1 h. Prior to all heat treatments， samples are sealed in vacuum quartz tubes to prevent oxidation. The microstructures and mechanical properties of the annealed specimens are characterized using electron backscatter diffraction， microhardness testing， and room-temperature tensile testing， respectively. [Results] AR greatly enhances the equivalent strain by introducing additional shear deformation， thereby promoting more uniform deformation penetration through the sheet thickness and forming a distinct shear zone. This results in more pronounced grain fragmentation compared to SR. Furthermore， the AR sample exhibits a markedly lower maximum texture intensity (24.76?mud) than the SR sample (74.12?mud)， along with a correspondingly reduced total texture fraction (54.2% vs. 74.8%). After annealing at 1 200 ℃， both samples achieved nearly complete recrystallization. The average grain size of the AR sample (50.70?μm) is finer than that of the SR sample (64.90?μm). As the annealing temperature increases， the texture intensity decreases for both samples， with the AR samples consistently exhibiting lower texture intensity than the SR samples. Rolling induced notable hardening， increasing the microhardness to 201.9?HV in the AR sample and 196.3?HV in the SR sample. The yield strength of the AR sample reached 378?MPa， which is 63?MPa higher than that of the SR sample (315?MPa). Although the mechanical properties of both rolled specimens exhibited decreasing trends with increasing annealing temperature， the strength and hardness of the AR samples remained consistently higher than those of the SR samples. [Conclusions] AR is an effective technique for refining the grain size of Ta， weakening its texture， and enhancing its mechanical properties. This experiment involves the preparation， characterization， and application of pure Ta， thereby not only improving students' experimental design skills but also promoting their scientific thinking and innovative awareness.
Instructional experimental design and operation for integrating curriculum ideology and politics into the outdoor education program “Safe Wilderness Classroom”
GONG Zhikai;SHEN Gang;ZHOU Zhuang;[Objective] Guided by the fundamental task of fostering virtue through education， the need to address the contradiction between talent supply and demand in China’s outdoor industry， as well as the disconnect between safety skill training and value guidance in traditional teaching， has made exploring effective pathways for integrating Curriculum Ideology and Politics an urgent priority. Relying on the “Safe Wilderness Classroom” instructional experiment at Changzhou University， this paper deeply analyzes the coupling mechanism between outdoor risk management and ideological educational elements. The study aims to reconstruct the three-dimensional objective system of knowledge， ability， and ideology. By embedding themes of life-safety orientation， patriotism， mountaineering spirit， and ecological civilization throughout the entire risk-response process， it explores a synergistic educational pathway to achieve the bidirectional enhancement of professional skill transfer and value internalization. This approach meets the industry’s urgent demand for compound talents with high safety literacy. [Methods] This study designed and operated a full-process outdoor instructional experiment system that transforms the student role from a passive learner to an active decision-making Outdoor Team Leader. The experiment used Maoshan in Jurong， Jiangsu， as the field site， requiring students to lead a two-day， one-night hiking and camping mission. The implementation was divided into three core phases. 1) Prepractice Phase: Following a process of mobilization， theoretical study， team building， and plan formulation， students used digital platforms to identify four risk categories: environmental， human， equipment， and compound risks. Student groups used tools such as risk matrices to formulate refined plans containing graded assessments and emergency contingency plans for specific routes， ensuring material readiness through multiple rounds of plan optimization. 2) In-practice Phase: Relying on the team leader responsibility system and a refined division of labor， groups executed their plans in authentic wilderness contexts. The instruction focused on reinforcing on-site decision-making capabilities and team synergy from the leader's perspective， employing daily structured debriefings to achieve dynamic calibration of outdoor risk management. Simultaneously， ideological elements were organically integrated with risk types: the life-safety orientation was integrated throughout the risk control process; patriotism was cultivated through red resources and role fulfillment; the mountaineering spirit was tempered during the 18-kilometer load-bearing hike; and ecological behavior was regulated by the Two Mountains theory and Leave No Trace principles. 3) Postpractice Phase: A mechanism for intragroup self-examination and intergroup cross-feedback was constructed to deeply analyze deviations in plan execution and the effectiveness of role fulfillment. Finally， relying on a comprehensive evaluation that included ideological dimensions， the study extracted risk checklists and a library of typical cases with promotion value， realizing the transformation from experiential reflection to the consolidation of educational outcomes. [Results] The experimental results had three main dimensions. 1) Risk Perception and Response Dimension: Students' outdoor safety literacy was markedly enhanced， achieving a transformation to active， systematic environmental screening and risk mitigation concepts. 2) Decision-making and Execution Dimension: When facing compound risk situations， the organizational resilience and collaborative decision-making capabilities of the teams were strengthened， enabling rational judgments based on evidence chains. 3) Value Internalization Dimension: The organic fusion of professional teaching and Curriculum Ideology and Politics was achieved， where abstract values were concretized into behavioral norms and responsibilities within the wilderness environment. [Conclusions] This study deeply coupled outdoor risk management skills and ideological educational values by constructing a systematic management framework covering prepractice， in practice， and postpractice. The research proves that integrating life-safety orientation， patriotism， mountaineering spirit， and ecological civilization into real tasks of risk identification， assessment， and response greatly enhances students' practical abilities to solve complex problems and their sense of social responsibility. This model effectively resolves the disconnect between safety education and ideological education in traditional outdoor teaching， providing a replicable paradigm and empirical reference for safety education and curriculum reform in university outdoor education.
Design of a Visual Test Platform for Sealing Performance Testing of Gas Lift Plungers
YU Yanqun;SUN Xiaoyu;HUANG Xiaoguang;TIAN Jiaoshen;WANG Longting;ZHONG Haiquan;JI Renjie;[Objective] As gas wells enter the mid-to-late stages of development， reservoir energy depletion leads to increasingly severe liquid loading in the wellbore， which markedly restricts gas production efficiency and may even result in well shut-in. Plunger gas lift is widely applied as an economical and effective deliquification technology; however， its overall performance is strongly governed by the sealing behavior formed within the annular clearance between the plunger and tubing. Because the downhole environment is inaccessible and conventional monitoring techniques provide only indirect information， the actual motion characteristics of plungers and the associated dynamic gas–liquid sealing processes during lifting remain insufficiently understood. Consequently， reliable experimental evidence for elucidating sealing mechanisms and comparing different plunger structures is still lacking. The objective of this study is to develop a visualized experimental platform for gas lift plunger sealing performance testing， to enable direct observation and quantitative characterization of plunger motion and gas–liquid distribution， to establish a comprehensive sealing performance evaluation method， and to provide experimental support for plunger structure optimization as well as experimental teaching and research training in oil and gas equipment engineering. [Methods] A full-scale visual experimental platform simulating a tubing–casing wellbore configuration was designed and constructed with an overall height of 11 m. Transparent tubing sections were adopted to realize direct visualization of plunger motion， liquid film development， and gas–liquid interface evolution throughout the lifting process. The platform integrates a gas supply system， liquid injection system， wellbore simulation system， safety protection system， and a multi-parameter measurement system. Compressed air is used to simulate formation gas supply， while a controllable water injection unit establishes different initial liquid loading conditions. High-speed imaging， displacement and velocity measurement units， and pressure sensors installed at the wellhead and bottomhole enable synchronous acquisition of plunger kinematics， pressure variations， and liquid production during each lifting cycle. Based on these measurements， a multi-dimensional sealing performance evaluation method is proposed by integrating pressure-loss characteristics and liquid leakage behavior. The average pressure loss during stable upward motion is used to characterize flow resistance induced by the sealing structure， whereas liquid leakage volume and liquid carrying ratio are determined using a volumetric approach. [Results] Visualized observations show that， during plunger ascent， a liquid film is formed in the annulus between the plunger outer surface and the tubing inner wall， while intermittent liquid backflow occurs owing to the formation and rupture of leakage channels in the sealing zone. Distinct differences in gas–liquid interface morphology， leakage patterns， and flow stability are observed among different plunger structures. Quantitative analysis demonstrates that the rotary fishbone plunger consistently exhibits a higher liquid carrying ratio and a more stable pressure-loss response across a wide range of operating conditions compared with the solid fishbone plunger. In particular， under medium-to-low gas injection rates and relatively high liquid loading conditions， the rotary fishbone plunger shows significantly enhanced liquid lifting capability and a lower leakage tendency. By contrast， the solid fishbone plunger is more prone to liquid backflow and displays larger fluctuations in pressure loss， especially under high liquid loading conditions. These results indicate that plunger structural configuration plays a decisive role in determining sealing behavior. [Conclusions] A visualized experimental platform for gas lift plunger sealing performance testing has been successfully developed， enabling direct observation of plunger motion and gas–liquid distribution together with synchronous measurement of key operational parameters. A multi-index sealing performance evaluation method integrating pressure-loss characteristics and liquid leakage behavior has been established and experimentally validated. The results confirm that plunger structural configuration exerts a strong influence on sealing performance and liquid lifting efficiency， and that the rotary fishbone plunger provides superior overall performance under most tested conditions. The proposed platform and evaluation methodology provide a reliable experimental foundation for plunger structure optimization and performance verification. In addition， the platform offers an effective tool for experimental teaching， graduate training， and research-oriented education in oil and gas equipment engineering and unconventional energy development.
Design of piezoelectric energy harvester based on liquid-solid-magnetic multi-field coupling effect
MA Wenjiang;ZENG Peng;LIU Donghuan;[Objective] With the development and application of micro electro mechanical systems (MEMS)， their need for environmentally friendly and reliable energy supply is becoming increasingly prominent. Environmental vibration as a common energy source in life， is very consistent with the energy supply needs of MEMS. Among them， the piezoelectric vibration energy harvester has been studied by a large number of scholars because of its simple conversion structure， high efficiency， low heat generation， easy processing and easy integration. At present， how to make piezoelectric vibration energy harvesters having higher energy harvesting efficiency and wider energy harvesting frequency band is one of the research hotspots of scholars. [Methods] In this paper， we take the liquid-solid-magnetic multi-field coupled piezoelectric vibration energy harvester as the research object， and establish the mechanical model of the energy harvester. And the experimental test and parameter analysis of the energy harvester to obtain the output of the energy harvester and the influence of each parameter on the harvesting efficiency of the energy harvester， to verify the feasibility of the captor， and to provide a reference for the design of a new type of captor， the main research content and research results of this paper are as follows. [Results] A new type of liquid-solid-magnetic multi-field coupled piezoelectric vibration energy harvesting structure is proposed， in which the proof mass of the traditional cantilever energy harvester is replaced by a liquid-filled container with ferromagnetic fluid and permanent magnets of different positions and distances are arranged around it. Based on the energy method， the lumped parameter model of the liquid-solid-magnetic multi-field coupled piezoelectric vibration energy harvester is established; subsequently， the expressions for the nonlinear magnetic force and the sloshing force are deduced by the magnetic dipole method and the potential flow method， and the mechanical model of the liquid-solid-magnetic multi-field coupled piezoelectric vibration energy harvester is obtained. A liquid-solid-magnetic multi-field coupled piezoelectric vibration energy harvester is designed and manufactured， and the related experimental test system is built， and the output of the energy harvester is tested under harmonic excitation and random excitation for sloshing and magnetic force variables. The experimental results show that the sloshing can make the energy harvester exhibit a multi-peak response， and the addition of nonlinear magnetic force changes the resonant frequency of the energy harvester on the one hand， and on the other hand， the magnetic force will have an effect on the sloshing in the container energy harvester， which will change the output characteristics of the energy harvester. By choosing the appropriate type of liquid， height-to-diameter ratio， and the appropriate magnet position and distance， the energy harvesting efficiency of the energy harvester will be effectively enhanced， and the feasibility of the liquid-solid-magnetic multi-field coupled energy harvester is verified. [Conclusions] Based on the theoretical model and experimental tests， the parameters of the liquid-solid-magnetic multi-field coupled piezoelectric vibration energy harvester are investigated. The effects of the structural parameters of the energy harvester， sloshing parameters， and magnetic parameters on the output characteristics of the energy harvester are further investigated， which provides a reference for the design optimization of the liquid-solid-magnetically coupled piezoelectric vibration energy harvester.
Design and Application of an Experimental Teaching Platform for Attitude Inversion of Magnetofluid Robots
ZHANG Jiameng;LIU Yanfang;CHEN Zhe;YANG Wenrong;[Objective] Posture inversion of magnetic liquid robots is a core research direction for their precise manipulation. Conducting relevant experiments helps students master key technologies such as magnetic field sensor array design and posture inversion methods， deepens their understanding of theories including medical-engineering integration and electromagnetic control， and cultivates students’ engineering practice and scientific research innovation abilities， laying a solid foundation for cultivating interdisciplinary talents.[Methods] In this paper， an experimental teaching platform for magnetic liquid robot posture inversion is constructed. Firstly， a magnetic liquid robot suitable for the human aortic environment is designed and fabricated by silicone 3D printing. The posture inversion problem of the magnetic liquid robot is transformed into the minimization problem of an objective error function， and an improved differential evolution algorithm with an adaptive operator is proposed for posture inversion. Meanwhile， to achieve economical and lightweight design， the magnetic field sensor array is optimized according to the contribution value of each sensor and spatial uniformity constraint. Based on this experimental teaching platform， a three-level experimental scheme consisting of basic， advanced and innovative experiments is designed. The basic experiment “Data acquisition and processing of magnetic liquid robot posture” enables students to master the knowledge of medical magnetic liquid robot posture inversion， the measurement method of magnetic field sensor arrays， and the processing of position information. The advanced experiment “Posture inversion experiments of magnetic liquid robot under different bending deflections” helps students master the improved differential evolution algorithm model based on neural network， verify the basic response relationship between position information and posture， and realize simple posture inversion. The innovative experiment “Posture inversion of magnetic liquid robot in simulated blood vessel environment” establishes a static aortic model， optimizes the posture inversion algorithm， and improves the inversion accuracy under complex structures. Relying on this platform， theoretical knowledge is integrated with practical applications to evaluate students’ mastery of knowledge related to magnetic liquid robots， magnetic sensor arrays and posture inversion methods. [Results] In the posture inversion experiments with deflection angles ranging from 0° to 40°， the actual posture of the magnetic liquid robot is basically consistent with the inverted posture. The maximum error is 3.2 mm， and the average prediction error of measurement points is less than 2 mm. In the posture inversion experiments in a simulated blood vessel environment， the maximum error of measurement points is 3.5 mm， and the average prediction error is less than 2 mm. The above results verify the effectiveness of the model in three-dimensional spatial posture inversion and realize the posture inversion of the magnetic liquid robot. [Conclusions] This platform provides strong support for cultivating practical ability and innovative thinking of students majoring in electrical engineering， biomedical engineering and robotics under the background of emerging engineering education. It conforms to the interdisciplinary and innovative education concept and provides a high-quality environment for students’ practice and innovation. It is expected that the platform can play a greater role in wider application scenarios and make greater contributions to cultivating high-quality application-oriented talents in the fields of magnetic liquid robot control and intelligent algorithm application.
Exploration and Implementation of Integrated Wastewater Treatment Facilities in Old Campus Laboratories
HUANG Xiaoyong;LU Kuan;[Objective] The treatment of wastewater from university laboratories is receiving increasing attention. However， due to constraints on campus land use， wastewater facilities in many old campuses are hampered by existing municipal pipelines， building layouts， and budgetary limitations， thereby becoming a bottleneck for the development of university laboratories and academic disciplines. Enhancing wastewater management in old campus laboratories is conducive to preventing environmental pollution， controlling disease transmission， safeguarding the health of staff and students， and promoting high-quality scientific research development within higher education institutions. [Methods] This article conducted sampling tests on wastewater discharged from laboratories in the old campus. Based on the water quality test results and flow characteristics， the effluent quality targets for the new wastewater treatment facility were determined. The wastewater treatment process selected is an integrated advanced oxidation， flocculation sedimentation， Anaerobic-Anoxic-Oxic(A/O) process. The main facilities adopt an underground configuration， positioned beneath the existing roadway. The main materials of the equipment utilise integrated stainless steel to ensure sealing integrity. The project team modified the existing drainage network， surveyed and compared the piping materials of the existing building's water supply and drainage systems， and selected reliable old pipes for reuse.The project utilises existing drainage wells as wastewater collection chambers. Following disinfection in the treatment tank， the effluent is discharged through a Parshall flume flow meter into the original drainage outlet. This project incorporates baffle plates within the flocculation sedimentation tank to enhance reaction efficiency. These plates create agitation and flow guidance， minimising vortex formation and ensuring complete sedimentation of deposits within the tank. The system employs microcomputer control to automate pump operation. Simultaneously， it issues control commands for each independent anaerobic， anoxic， and aerobic reaction zone， regulating influent flow， recirculation ratios， and carbon source distribution. This achieves varying degrees of denitrification and phosphorus removal. Finally， The article evaluates the project's effectiveness from three aspects: effluent quality， investment costs， and operational costs. [Results] The operational results of the wastewater treatment facilities indicate: 1. All effluent quality parameters meet the Grade II standards of the Guangzhou Wastewater Discharge Standards， with suspended solids (SS) at 35 mg/L and heavy metal chromium at 0.12 mg/L， achieving removal rates of 83.3% and 70% respectively. 2. The total investment for the renovation project amounted to approximately ￥1，585，700. With a daily wastewater treatment capacity of 80 tonnes， the unit investment per tonne treated stands at ￥19，800. This represents a higher investment efficiency compared to the ‘micro-electrolysis – flocculation sedimentation – contact oxidation’ small-scale treatment station. 3. The comprehensive operating cost is approximately ￥0.9 per cubic metre. Compared to other renovation projects， this project achieves over 20% savings in operational and maintenance expenses. 4. Compared to other above-ground wastewater treatment stations， this project reduces the land area requirement by 50%. [Conclusions] University laboratory wastewater is characterised by low volume and dispersed sources. Compared to conventional methods， the integrated wastewater treatment unit employing the advanced oxidation-flocculation sedimentation-A/O process demonstrates advantages including reduced footprint， lower initial investment， high automation levels， and minimal operational costs. Constrained by the limited space of the old campus， the selection of an integrated， underground wastewater treatment facility balances campus aesthetics with equipment durability. By refining sludge digestion technology， secondary pollution is reduced， minimising the environmental impact throughout the facility's entire lifecycle. This approach supports the national ‘dual carbon’ goals， offering a novel solution for laboratory refurbishment and wastewater management in the old campus.