NetWork
ROS-based experimental platform for network attack and detection in networked multi-robots
MA Lei;GUO Tilei;WANG Guoqing;DAI Wei;YANG Chunyu;[Objective]Networked robot cooperative control systems operating over open networks are vulnerable to cyber-attacks such as false data injection， replay， and denial-of-service， which can undermine leader–follower formation stability and control performance and complicate systematic security experiments. To address this issue， this paper designs and implements a ROS-based experimental platform for network attacks and threat detection in networked robots， integrating cooperative control， attack injection， and intelligent detection into a unified framework for teaching and research. [Methods]Built on the ROS communication framework and the Gazebo simulation environment， this platform includes a leader–follower formation control subsystem， a network attack injection subsystem， and a network attack detection subsystem. The leader–follower formation control subsystem facilitates the exchange of position and velocity information between a leader robot and multiple followers through ROS topics， supports common motion tasks like straight-line and circular trajectory tracking and various formation patterns， and offers a visualization interface that displays robot poses， inter-robot distances， and formation errors in real time. This provides an intuitive way to observe how cooperative behavior degrades under malicious interference. The network attack injection subsystem utilizes standard network analysis tools to identify host and traffic characteristics， creates a man-in-the-middle environment between the control workstation and the robots， and employs script-based configuration of packet payloads， sending rates， and target ports to simulate representative attack scenarios， including falsified state information， replay of historical data， and flooding-based denial-of-service， with adjustable intensity and duration. On the defense side， the detection subsystem constructs temporal samples by jointly analyzing network traffic statistics and the physical states of the robots， aligns and segments these heterogeneous data streams using timestamps and sliding time windows， and performs deep multimodal data fusion through feature-level concatenation and normalization before inputting them into a proposed CNN–BiLSTM–Attention model. In this model， convolutional layers extract local spatiotemporal patterns from the fused features， the bidirectional LSTM captures long-term dependencies between network conditions and cooperative movement， and an attention mechanism highlights time segments more indicative of abnormal behavior. The system then classifies attacks through a softmax output layer. Training involves weighted loss functions and regularization to address class imbalance and enhance generalization. [Results]Experimental results from datasets collected under normal operation and multiple attack scenarios demonstrate that the platform can reliably support multi-robot leader–follower formation simulations and accurately reproduce phenomena such as formation divergence， follower lag， increased communication delay， and higher packet loss. Compared to baseline models that only use network traffic or physical states as inputs， the proposed CNN–BiLSTM–Attention detector with deep multimodal data fusion achieves higher overall accuracy， precision， and F1-scores， and exhibits more balanced performance across attack types， especially those that are hard to distinguish using a single modality. These results show that combining attack injection experiments with multimodal learning significantly improves attack detection sensitivity and robustness. [Conclusions]Overall， the platform provides a comprehensive experimental chain—from theoretical explanation and attack simulation to intelligent defense—for network security education in cooperative robotic systems. Additionally， it offers a scalable and easily extendable testbed for investigating complex attack scenarios and developing cyber-physical defense strategies in realistic networked robot environments.
Design and implementation of virtual simulation-based experimental teaching for quarantine forest diseases
LIN Sixi;DING Xiaolei;CHEN Wei;ZHU Lihua;YE Jianren;[Objective] Forest pathology is a fundamental and compulsory course widely offered in forestry colleges and universities in China. However， due to the epidemic characteristics of forest diseases， experimental teaching in forest pathology has long faced several challenges. Firstly， it is challenging to systematically execute the teaching within a limited time， as it is not feasible to comprehensively demonstrate the entire disease process and development patterns. Secondly， it is difficult to accurately depict the real situation， as the existing experimental conditions cannot fully simulate the wild environment. Thirdly， the teaching style is constrained due to the irreversible nature of inoculation experiments. Moreover， major forest diseases involve quarantine pathogens， making it inappropriate to conduct such experiments in open environments. The introduction of virtual simulation experiments provides a viable technical solution to address these challenges. [Methods] This project has been initiated to address a pressing national concern: the control of pine wilt disease， a highly significant quarantine disease in China. It focuses on the most critical prevention step (disease diagnosis) of this disease to carry out the experiment design. The project is supported by extensive teaching and research achievements accomplished by our research group over the past two decades. In addition， the project leveraged virtual simulation technology to introduce classic disease diagnosis experiments into a virtual laboratory， thereby enabling full reproduction of the entire process of pine wilt disease diagnosis and pathogenicity determination. The system recreates highly realistic virtual environments， including wild forests， laboratories， and greenhouses. The diagnostic process is meticulously structured into three primary modules: disease cognition， disease diagnosis， and pathogenicity determination， comprising 14 interactive steps corresponding to 24 assessment points. The multilevel assessment method enables comprehensive evaluation of the experimental outcomes and students’ abilities to analyze and solve problems in error-tolerant scenarios， while also helping optimize the curriculum system and experimental teaching content. [Results] The experiment successfully addressed several issues， such as the prolonged duration of pine wilt disease diagnosis experiments， the irreversibility of destructive experiments， the stringent requirements for experimental environments， and the lack of suitable conditions in non-infected areas. It has effectively compensated for the disadvantages of traditional forest pathology experiments. The experimental background data are derived from long-term scientific achievements obtained by top national research teams， providing substantial data support for the establishment of experimental projects， facilitating the transfer of recent advances into teaching， and ensuring the validity of contents and the accuracy of results while also reflecting innovation and cutting-edge techniques. The virtual experiment begins with a distressing depiction of pine wilt disease， which has led to a substantial mortality of pine trees and a consequent ecological crisis. The sequence of events commences with a simulation request from the National Forestry and Grassland Administration. This configuration will help users in dedicating themselves to experiments in disease diagnosis and pathogen identification. The program enables students to engage in experimental simulation， online interaction， and experimental assessment， thereby achieving closed-loop verification of Koch’s postulates within constrained teaching time， satisfying the systematic integrity of experimental teaching content. [Conclusions] This virtual simulation experiment underscores the importance of innovation in experimental teaching models and the advantages of virtual simulation technology. It expands the breadth and depth of experimental teaching in forest pathology， achieving a profound integration of modern information technology with experimental teaching methodologies. Additionally， it incorporates political elements to enhance students’ identification with their major. Through a dual-dimensional training model of “technical ability + political literacy，” it effectively cultivates students’ sense of social and professional mission， stimulates their patriotic sentiments of being a tree doctor， and provides strong support for cultivating high-quality agricultural and forestry talents in the new era.
Optimization of Critical Parameters for Cryo-Focused Ion Beam Milling
LI Xiaomin;LEI Jianlin;[Objective] Although cryo-electron microscopy (cryo-EM) is widely used for determining three-dimensional structures of isolated and purified biomacromolecules， high-resolution structural studies of cells and tissues in their native context still depend on the preparation of high-quality ultrathin sections. Focused ion beam (FIB) milling has emerged as a key technique for producing ultrathin cryo-lamellae from in situ samples， due to its minimal artifacts and precise targeting capability. This study systematically investigates critical factors influencing the quality of cryo-lamellae prepared by FIB milling， including sample vitrification quality， accurate temperature control of the cryo-system， ice deposition and contamination. [Methods] We studied the entire process from sample preparation to lamella assessment using an Aquilos 2 cryo-FIB/SEM microscope. Diverse biological samples—yeast cells， 293T cells and isolated muscle fibers—were prepared. Cells were vitrified by plunge freezing， while muscle fibers were pre-treated with glycerol before vitrification in an ethane/propane mixture for homogeneous vitrification. A systematic FIB milling protocol was established: initial coarse milling (1-3 nA beam current) created trenches and stress relief cuts， followed by sequential thinning with beam current reduced stepwise from 1 nA to 50 pA， and final polishing at beam currents as low as 10 pA to produce 100–200 nm lamellae. With this protocol， key operating parameters were meticulously optimized based on experimental results: (1) Sample vitrification quality was first assessed during FIB-SEM milling and then correlated with cryo-ET outcomes to identify failure signatures. (2) A temperature sensor was directly instrumented on the shuttle to measure the true thermal conditions at the sample， guiding the optimal waiting period before loading according to the cooling kinetics profile. (3) Ice deposition inside the microscope chamber was evaluated by imaging the lamella at regular intervals after coarse milling. Rapid ice accumulation led to a significant increase in lamella thickness-nearly doubling within 1.5 hours， for example-and caused edge curling， both of which degraded sample quality. (4) Based on a study of ice contamination mechanisms， a custom integrated loading device with an anti-contamination lid was specifically designed to reduce ice formation during sample package and transfer procedure and fully tested against standard methods. [Results] Primary challenge in cryo-sample preparation stems from inherent limitations of plunge-freezing. Effective vitrification requires a coordinated strategy of sample pre-treatment and freezing medium optimization， while for larger biological specimens， high-pressure freezing is essential to achieve uniform vitrification. A consistent measurement bias was observed， with the system temperature underreported relative to the actual grid temperature， necessitating direct temperature calibration. A major finding was the detrimental impact of rapid ice deposition on lamella integrity. Enhancing the chamber vacuum via system upgrades effectively mitigated this issue， maintaining stable lamella thickness throughout extended chamber sessions. An integrated loading device was developed to reduce ice contamination during package and transfer. Additionally， key technical parameters—platinum coating uniformity， ion beam milling settings， and machining precision—were also identified as critical factors for producing high-quality lamellae. [Conclusions] By integrating systematic analysis with experimental data， we demonstrate that complete vitrification is prerequisite for successful milling， reveal the critical discrepancy and its practical implications between the displayed system temperature and the actual sample temperature， and confirm that enhancing chamber vacuum is vital for controlling ice deposition， thereby providing an effective solution to reduce ice contamination. This work presents a reliable workflow and optimized strategies， offering concrete guidance to improve the robustness and reproducibility of FIB-based thinning for in situ structural biology.
Research on the architecture design and operational mechanism of an intelligent safety management system for university laboratories
LIU Daijun;LU Yi;[Objective] University laboratories， as critical hubs for scientific innovation， face escalating safety management challenges. Traditional paradigms， reliant on periodic manual inspections and static compliance checklists， are increasingly inadequate， suffering from inherent deficiencies: static risk perception， fragmented management elements， and a reactive response mode. The misalignment between safety management and the dynamic life cycle of experimental activities makes it difficult to adequately address the coupled and complex risks in modern research， transforming safety from an enabler of research into a heavy operational and administrative burden.Therefore， this study aims to transcend these deep-seated limitations by proposing a systematic， integrated framework to drive a fundamental paradigm shift in laboratory safety management from static， passive compliance to proactive， dynamic， and intelligent governance， thereby unifying safety assurance with scientific development.[Methods] This research constructs a comprehensive solution comprising a novel theoretical model， a supporting technological architecture， and a defined operational mechanism. First， the core innovation is the WSR-T dynamic safety management model. It integrates the Time/Process (T) dimension-operationalized into three sequential phases: Pre-experiment (T1: Prevention and Preparation)， During-experiment (T2: Monitoring and Execution)， and Post-experiment (T3: Restoration and Learning)-orthogonally with the Wuli (Physical)， Shili (Procedural)， and Renli (Human) dimensions of the WSR systems methodology. This integration forms a dynamic management matrix that reframes safety as continuous control over the entire experimental life-cycle trajectory. Second， to enable this model， a Multi-Agent collaborative Digital Twin-enabled Cyber-Physical System (MA-DT-CPS) architecture is designed. Its foundation is a high-fidelity digital twin， which integrates five core computational models: a Geometric model for spatial semantics， a Physical model for real-time monitoring and simulation， a Rule model that formalizes regulations and procedures， a Behavior model for quantifying human actions and states， and a Process model that creates intelligent digital threads for each experiment's life-cycle. Within this digital environment， a collaborative multi-agent system operates， featuring specialized agents for Situational Awareness， dynamic Risk Assessment， Compliance Execution， Emergency Decision-making， and system Learning & Optimization. This system is designed to operate in a three-tier hybrid-intelligence mode: full automation for routine tasks， suggestion mode for uncertain scenarios， and co-creation for novel situations. Finally， the study details the "Perception-Mapping-Analysis-Decision-Execution-Learning" event-driven closed-loop operational mechanism， specifying how the architecture implements the logic of the WSR-T model for dynamic， intelligent control. [Results] The study yields a holistic and actionable framework. Theoretically， the WSR-T model provides a novel， structured lens， making complex laboratory safety events analyzable as specific spatio-temporal couplings of W， S， and R elements， thereby moving beyond static checklist compliance. Technologically， the designed MA-DT-CPS architecture translates this theoretical model into a concrete， actionable implementation path. The key results include: 1) A systematic methodology that re-contextualizes safety as a process of dynamic control; 2) A sophisticated technological blueprint enabling high-fidelity digital representation， autonomous agent collaboration， and human-machine synergy; and 3) A well-defined operational mechanism that transforms management from a periodic， plan-driven activity to an event-driven， intelligent closed-loop process. This integrated "theoretical model-technical architecture-operational mechanism" framework systematically addresses the root causes of static， fragmented， and passive management， providing a clear pathway for the intelligent transformation of laboratory safety systems. The framework enables proactive risk inference， virtual strategy testing via the digital twin sandbox， and a system capable of self-learning and continuous improvement based on operational feedback. [Conclusions] This research presents a systematic， end-to-end solution designed to overcome the fundamental challenges in modern university laboratory safety management. By integrating the time dimension into the WSR methodology， the WSR-T model establishes a robust theoretical foundation for life-cycle-encompassing， dynamic safety governance. The MA-DT-CPS architecture provides the necessary technological enablers， fusing digital twin and multi-agent system concepts to create a platform for realizing the model's logic. Together， they form a coherent framework that paves the way for the development of intelligent management systems that seamlessly embed safety requirements into the entire scientific workflow. This paradigm aims to unify the goals of safety assurance and scientific innovation at a higher level. Future work should focus on developing prototypes and conducting long-term empirical studies in real laboratory environments to validate， optimize， and iteratively improve the proposed system， with particular attention to the quantitative modeling of complex human factors and ensuring cost-effectiveness for widespread adoption.
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.
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.
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.