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Microwave over-the-horizon high-speed communication technology for offshore facilities in the South China Sea
WANG Jipeng;YI Jianbo;JIN Yunzhi;ZHENG Yangboyin;SU Ting;CNOOC China Limited Hainan Branch;[Objective] Offshore assets in the South China Sea, such as oil and gas platforms, offshore wind farms, maritime supervision nodes, and emergency response bases, are increasingly moving toward deep-water, far-offshore, and long-duty operations, which require backhaul links with high throughput, low latency, and high availability. Conventional line-of-sight microwave is limited by range, and geostationary Earth orbit satellites suffer from high latency. Therefore, this study develops and validates a practical, over-the-horizon(OTH) microwave communication solution that leverages evaporation ducts within the marine atmospheric boundary layer. The objectives are threefold:(i) establish a predict-then-deploy workflow that integrates a parabolic-equation(PE) propagation model with environmental data and engineering constraints;(ii) quantify capacity-stability co-design via polarization multiplexing and link aggregation for capacity and spatial diversity for stability; and(iii) verify engineering applicability using long-range field measurements from representative South China Sea links. [Methods] We develop a PE-based maritime radio channel model that incorporates refractivity profiles of the marine boundary layer, rough-sea impedance boundary conditions, and coastal/terrain data to predict transmission loss along candidate paths. The modeling follows a forward-propagating, narrow-angle PE with split-step fast Fourier transform marching, using antenna patterns as initial conditions and an absorbing layer aloft to mitigate spurious reflections. The transmission loss is referenced to free space at 1 m and sampled at the transmitter/receiver heights, adhering to standard engineering link-budgeting conventions. On the system side, we design a “microwave-primary, scatter/satellite-assisted” architecture for offshore production networks. Capacity enhancement is achieved through dual-polarization multiplexing and physical-layer link aggregation, and stability is improved using spatial diversity with combined reception to counteract sea-surface multipath, evaporation-duct variability, and platform motion. We instrument a typical land-to-platform link(135.3 km; land site altitude ≈420 m) for one month, recording adaptive modulation/coding states, received signal level(RSL), transmit power, bandwidth occupancy, and antenna-combining modes. End-to-end user datagram protocol(UDP) tests(iperf) are conducted to validate whether the configured capacity is realized at the service layer. [Results] The PE model accurately reproduces long-range evaporation-duct propagation. For the 135.3 km link, the measured maximum path loss is 209.89 dB, and the PE-predicted maximum is 208.59 dB, resulting in a difference of 1.30 dB under synchronized environmental conditions, confirming the model's predictability and applicability for planning and operations. Long-term statistics indicate that combined reception(spatial diversity) is the predominant mode during most periods, enhancing link availability and maintaining the decision margin required for higher-order adaptive modulation. Time-occupancy analysis indicates that high-order modes(16/32/64 QAM) dominate, whereas low-order modes(QPSK/4/8 QAM) only appear briefly during adverse channel conditions. Consistent with these distributions, daily RSL ranges remain high on most days, with occasional troughs attributable to boundary-layer changes, sea-surface multipath, or weather transitions. The system's capacity envelope shows a stable lower bound(≈26.355 Mb/s under conservative ACM settings) and a peak near 184.079 Mb/s at 64 QAM. When aggregating three links with a 1∶1 split between uplink and downlink, the configured aggregate capacity reaches ≈1.1 Gbps, which is verified at the service layer: end-to-end UDP throughput achieves ～557 Mb/s uplink and ～551 Mb/s downlink(total ～1.108 Gb/s) under 40 MHz channels, 64 QAM, and combined reception as the normal operating mode. These results confirm that the “capacity via polarization/aggregation + stability via spatial diversity” co-design achieves high spectral efficiency and availability on long OTH paths in realistic sea states. [Conclusions] By integrating a PE-based, environment-coupled propagation model with an engineering architecture that optimizes capacity and stability, we link propagation predictability to operational utility for OTH microwave communication in the South China Sea. The modeling-measurement agreement( ≤1.30 dB on maximum path loss at 135.3 km) provides a foundation for scenario-specific planning and parameter selection. In continuous operation, spatial-diversity combining emerges as the default mode, significantly enhancing availability and sustaining higher-order modulation over extended periods, whereas polarization multiplexing and link aggregation yield near-linear capacity scaling up to the tested ～1.1 Gb/s aggregate. The proposed workflow and parameter baselines are reproducible for deep-water, far-offshore facilities requiring low-latency, high-availability backhaul, offering a transferable template for the deployment and evolution of microwave-centric offshore networks in evaporation-duct-prone maritime environments.
Electromagnetic spectrum sensing experiments and prediction models in the marine environment
LIU Yanlong;CHEN Zhenjia;[Objective] There is growing demand for accurate ocean environmental monitoring and spectrum sensing technology, and traditional single-sensor systems are no longer enough to meet the technical needs of multidimensional parameter collection and analysis. To address this challenge, we developed a custom maritime monitoring system designed to achieve efficient, stable, and continuous observations of both oceanic meteorological conditions and electromagnetic spectrum distribution. [Methods] This intelligent platform with multimodal sensing capabilities integrates five main functional modules: a positioning and attitude sensing unit, a meteorological parameter collection unit, a data storage and management unit, a remote communication module, and an electromagnetic spectrum reception module. It allows for the synchronized collection and local processing of more than ten key parameters, including wind speed, wind direction, attitude angles, power supply data, and electromagnetic signal strength. Structurally, the platform features a modular, low-power design, making it suitable for long-distance deployment and mid-to long-term operation, greatly enhancing deployment flexibility and data continuity on the ocean surface. The principles and procedures of electromagnetic signal reception are described in detail here. Regarding the field measurement process, sensor attitude was examined, and a preliminary analysis was performed on how platform orientation and meteorological factors(such as wind speed and direction) influence signal strength. A compensation model for platform attitude was then proposed. To evaluate the platform's performance, it was deployed in a typical dynamic maritime environment to continuously record the received signal strength indicator(RSSI) within a target frequency band. Real-time attitude data(pitch, roll, and yaw) and meteorological variables(wind speed and direction) were recorded simultaneously. Using the collected data, both linear and nonlinear multivariate regression models were developed to analyze how platform motion and environmental disturbances impact signal reception. Linear models proved insufficient to capture the complexity of attitude and meteorological influences on signal strength, leading to the adoption of a random forest regression algorithm, which demonstrated strong performance in handling nonlinear and multivariable interactions. [Results] Results reveal a significant negative correlation between yaw angle and RSSI, with wind direction deviation also exerting a moderate influence on signal strength. When compared to the XGBoost and SVR algorithms, the random forest model showed superior accuracy and stability, achieving an R2 value greater than 0.84, indicating a high explanatory power of platform attitude and environmental factors on signal strength variations. [Conclusions] This study is the first to incorporate multi-source heterogeneous environmental sensing data into signal strength modeling. It introduces a novel analytical framework tailored for dynamic marine environments that improves spectrum sensing accuracy and stability on mobile platforms. Both theoretical insights and experimental validation are provided. The proposed system and methodology demonstrate strong scalability and broad applicability, suitable for uses such as marine meteorological monitoring, maritime electromagnetic interference detection, and wireless communication link assessment. Additionally, this system will serve as a valuable educational tool in universities, supporting both teaching and practical training.
International experience and reference in the management of funds for national research institutions: A case study of the United States, the United Kingdom, Germany, and Japan
DING Xiaoxia;GONG Yukai;Yazhouwan Laboratory;[Objective] National research institutions are strategic scientific and technological organizations that exemplify national will, fulfill national missions, and represent national standards. Moreover, the management of funds is the fundamental guarantee for their efficient operation and the enhancement of their innovation capabilities. This article aims to provide theoretical and practical guidance to enhance the funding guarantees and management levels of national research institutions in China, thereby achieving the goal of becoming a strong country in science and technology. [Methods] This article reviews and summarizes the fund management experience of national research institutions in the United States(US), the United Kingdom(UK), Germany, and Japan. This study combines the data characteristics of typical laboratories in these four countries to extract the key mechanisms of internationally mature fund management: fund allocation, fund structure, fund supply, and evaluation feedback. [Results] First, drawing on the financial management experience of the US Department of Energy's national laboratories and focusing on national strategic tasks, a financial allocation method centered on strategic priorities should be established, with differentiated support for various scientific research activities. Second, informed by the financial management experience of the UK National Physical Laboratory and the German Fraunhofer Society, a diversified financial support structure should be explored that fully demonstrates the institutional advantages of China's “national system” of concentrating resources to achieve significant goals. Third, building on the financial management experience of the German Max Planck Society and the Japanese Industrial Technology Comprehensive Research Institute, funds should be allocated with the goal of “talent” cultivation, so as to conduct research on the innovation of scientific research systems and mechanisms, maximize the release of research vitality, and innovate the system of financial supply and use. Fourth, with reference to the financial management experience of the US national laboratories, the German Fraunhofer Society, and the German Max Planck Society, the performance evaluation system, evaluation indicators, and result feedback should be further improved to strengthen the effectiveness of financial performance evaluation and result feedback. [Conclusions] This study compares international experiences and proposes the establishment of a “task-resources-talent-performance” funding management model to develop a scientific, standardized, and dynamically optimized funding management system in China's national-level research institutions. First, in the “task” aspect, institutions should establish the funding allocation principle of “prioritizing national strategies” and allocate funds accordingly. They should ensure that the funding is highly aligned with the mission of the tasks, and improve the strategic supporting effectiveness and classified support functions of fiscal funds. Second, in the “resources” aspect, institutions should coordinate central appropriations, local investments, and social capital. They should also explore a diversified funding structure based on central fiscal resources, supplemented by local and industry resources, and flexible expansion through industry-university-research cooperation. Third, in the “talent” aspect, institutions should grant project leaders a specific scope of authority for budget coordination and resource allocation. They should also explore a package-based funding system, along with other funding models focused on the capabilities and strategic contributions of scientific research teams, and promote a funding environment that attracts top talent and stimulates innovation. Finally, in the “performance” aspect, institutions should improve the funding evaluation and feedback mechanism, and perfect the evaluation system, evaluation indicators, and feedback on funding use. They should also strengthen the link between performance evaluation feedback and dynamic allocation of funds and form a virtuous cycle of “promoting use through evaluation and promoting effectiveness through use.”
Continuous learning-based few-shot synthetic aperture radar ground target recognition
ZHOU Yun;LI Junyi;REN Haohao;MIAO Lei;FAN Liwei;[Objective] This study aims to address critical challenges in open-environment synthetic aperture radar(SAR) applications, where high-value targets continuously emerge but labeled samples remain scarce. The study proposes an orthogonality-constrained distribution-calibrated replay method for continuous learning in SAR target recognition. Unlike traditional deep learning models, which assume closed environments with abundant data, this method targets the stability–plasticity dilemma, aiming to resolve the dual problems of catastrophic forgetting of old knowledge and overfitting on limited new data. [Methods] First, during the initial base class training phase, the proposed method establishes a highly structured embedding space to reserve non-overlapping geometric regions for future classes. It optimizes the feature space by utilizing a combined orthogonal prototype distribution and intra-class compactness loss. Specifically, the method employs an iterative process to construct an orthogonal basis space by selecting prototype vectors with the lowest cosine similarity to existing bases and projecting them into the orthogonal complement space. This approach ensures that the embedding space is inter-class separable and intra-class compact, leaving adequate room for future incremental classes. When new classes are accommodated, a dual knowledge preservation method is proposed to mitigate catastrophic forgetting of old knowledge during incremental updates by integrating orthogonal gradient projection and distribution-calibrated replay. Orthogonal gradient projection minimizes interference with established knowledge by constraining the update direction. It projects gradient updates into the orthogonal space of the base class feature matrix, such that the model's response to old classes remains invariant. However, achieving a strictly orthogonal space is challenging, and gradual drift still occurs. To further recall old class knowledge from the feature distribution of previous classes, we employ distribution-calibrated replay to reinforce historical knowledge by generating and rehearsing high-fidelity pseudo-features. This strategy utilizes a Gaussian sampler based on the statistics of old classes and introduces a learnable recursive calibrator to correct deviations between the sampled Gaussian distribution and the complex real feature distribution. By minimizing the Kullback–Leibler(KL) divergence between the generated and real distributions, this module replays high-quality pseudo-features that effectively consolidate memory. To enhance the model's robust generalization on scarce new classes, a self-supervised progressive learning strategy is proposed that advances from easy to hard tasks, ensuring effective feature mining from limited samples. This includes a rotation-based self-supervised branch optimized with an uncertainty-weighted focal loss, which effectively optimizes the feature extractor. The self-supervised branch encourages the model to learn azimuth-invariant features, thereby mitigating overfitting. In addition, the uncertainty-weighted focal loss dynamically assigns higher weights to hard-to-classify samples based on prediction probabilities, encouraging the model to focus on mining discriminative features. [Results] Experiment results on the moving and stationary target acquisition and recognition, and SAR AIRcraft-1.0 datasets validate the effectiveness of the proposed method. It significantly outperforms state-of-the-art methods, demonstrating superior efficiency and stability by achieving the highest recognition accuracy with minimal accuracy drop across various scenarios, including different numbers of incremental classes, varying incremental sample sizes, and distinct datasets. Ablation studies confirm that the proposed stability and plasticity modules enhance target recognition performance. [Conclusions] By integrating orthogonal gradient projection, distribution calibration replay, and self-supervised progressive learning, this paper successfully addresses the inherent challenges in continuous learning, providing a robust solution for dynamic SAR automatic target recognition.
Effect of soaking time on the physicochemical properties and mineralization efficiency of low-calcium fly ash–CO_2
LI Qian;PENG Jiansong;XIA Binwei;[Objective] The global greenhouse effect is escalating, leading to the progressive deterioration of ecosystems and climate worldwide. As the primary greenhouse gas, reducing CO2 emissions is crucial for effectively mitigating this effect. Fly ash–CO2 mineralization and sequestration technology represents a promising approach for carbon fixation and emission reduction. However, the low carbonation efficiency of fly ash–CO2 remains the central constraint hindering effective CO2 mineralization and sequestration. Thus, elucidating the microscopic mechanisms and key influencing factors of fly ash–CO2 carbonation is essential toward addressing this limitation. [Methods] To investigate these issues, a custom-designed setup was used to conduct experiments, including conventional immersion, immersion–carbonation, and microstructural characterization tests to examine the effects of immersion time on alkaline metal ion leaching and diffusion, as well as the impact of the microstructures of fly ash and CO2 on the carbonation efficiency. [Results] Results show that the p H increase rate exhibited a negative exponential decay relative to immersion time. After 24 hours of immersion, the carbonation efficiency and sequestration capacity reached peak values of 12.855% and 12.91 kg/t, respectively, representing a 0.25-fold increase over non-immersed fly ash. Raw, unmineralized fly ash contains amorphous silica(SiO2), mullite(Al2 Si O5), and amorphous silica hydrate(SiO2·x H_2O). No diffraction peaks were detected for calcium carbonate, calcium hydroxide, or magnesium hydroxide, confirming the absence of calcium carbonate in the original sample. Conversely, the mineralized sample contained phases such as amorphous silica hydrate(SiO2·x H_2O), quartz(SiO2), mullite(Al2 Si O5), calcium carbonate(CaCO3), and hydroxides(Ca(OH)2 and Mg(OH)2). The absence of the magnesite diffraction peak indicated that magnesium did not participate in the mineralization reaction. Furthermore, the observed low-intensity diffraction peaks were broad, indicating low sample purity and small crystal size, confirming the predominantly amorphous composition of the matrix. The diffraction-peak intensity of calcium carbonate initially increased and then decreased with increasing immersion time, with the maximum mass fraction(1.10%) observed at the 24-hour mark. Raw fly ash particles were spherical and dispersed. By comparison, the carbonated samples exhibited agglomeration and cementation, peaking at the 24-hour mark, with amorphous calcium carbonate deposited on the particle surface. Additionally, the carbon content of the carbonated fly ash increased with immersion time(within 24 hours), indicating a higher carbonation degree. The frequencies of larger and smaller particles increased and decreased, respectively, with the immersion time(≤ 24 h), suggesting positive and negative correlations between larger and smaller particles and the carbonation degree, respectively. [Conclusions] This study investigated the leaching and diffusion characteristics of fly ash–derived alkaline metal ions and their impacts on the microphysicochemical properties of fly ash, as well as their relationship with CO2 mineralization efficiency. Through a series of experiments involving fly ash immersion across different durations, followed by mineralization tests and microstructural characterization of the mineralized fly ash, the influences of soaking time on the leaching and diffusion behavior of alkaline metal ions were evaluated. Additionally, the effects of leaching on the microstructure of fly ash, as well as the efficiency of CO2 mineralization, were examined. Overall, these findings provide theoretical guidance for optimizing reaction parameters and enhancing mineralization efficiency in fly ash–CO2 mineralization processes.
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.
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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.
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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.
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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.
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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.
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Study on the design and analysis methods of orthogonal experiment
Liu Ruijiang,Zhang Yewang,Wen Chongwei,Tang Jian(School of Pharmaceutics,Jiangsu University,Zhenjiang 212013,China)The importance of orthogonal experimental design and analysis is introduced briefly.The principle and characteristic are expounded.The design methods of orthogonal experiment and analysis methods of orthogonal experimental results are analyzed in detail,which afford fully systemic methods for orthogonal experimental design and analysis.Problems in orthogonal experimental design and analysis and development of software for orthogonal experimental design and analysis are also pointed out in the end.
[Downloads: 55,855 ] [Citations: 3,448 ] [Reads: 1044 ] HTML PDF Cite this article
Research on statistical analyses and countermeasures of 100 laboratory accidents
Li Zhihong;Training Department,Kunming Fire Command School;This paper summarizes 100typical cases of laboratory accidents from 2001and analyzes the cases in fields of accident type,accident link,accident cause,dangerous substance category,etc.The result shows as follows:the fire disasters and explosive accidents are the main types of laboratory accidents;the dangerous chemicals,instruments and equipment,and pressure vessels are main dangerous substances;the instruments and equipment and reagent application processes are the main links of accidents;the violation of rules,improper operation,carelessness,wire short circuit and aging are the main reasons of accidents.It also puts forward the countermeasures and suggestions for the prevention and control of laboratory accidents in the following aspects:establishing complete safety management system,actively promoting standard construction of laboratory safety,strengthening laboratory safety education and training,and formulating and improving emergency plans for laboratory accidents.
[Downloads: 10,651 ] [Citations: 568 ] [Reads: 130 ] HTML PDF Cite this article
Promotion of reform and innovation on integration of theory teaching and experimental teaching by virtual simulation experiment teaching
XIONG Hongqi;Based on the concept of experimental teaching and its importance, the connotation of virtual simulation experimental teaching is expounded upon. On this basis, this paper puts forward six balance principles that virtual simulation experimental teaching should follow to promote the upgrading and reconstruction of traditional experimental teaching and elaborates the reform idea of virtual simulation experiment teaching for the overall optimization and innovation of theory teaching. The brief analysis is carried out on that the introduction of virtual simulation experimental teaching is conducive to promoting innovation and entrepreneurship education into the whole process of professional education.
[Downloads: 4,967 ] [Citations: 319 ] [Reads: 89 ] HTML PDF Cite this article
Research and application of BOPPPS teaching method in MOOC teaching design
WU Changdong;JIANG Hua;CHEN Yongqiang;School of Electrical Engineering and Electronic Information,Xihua University;School of Information Science and Technology,Southwest Jiaotong University;On the basis of introducing the connotation of BOPPPS(bridge-in,objective,pre-assessment,participatory learning,post-assessment and summary)model,this paper explores upon the guiding role of the BOPPPS teaching model in MOOC teaching design.Based on the BOPPPS model,MOOC teaching design of"Series feedback voltage stabilization circuit"is carried out.This provides some reference for improving the quality of MOOC teaching design,stimulating students' learning interest and motivation,and promoting teachers' reform of teaching content design.
[Downloads: 3,873 ] [Citations: 272 ] [Reads: 75 ] HTML PDF Cite this article
The application of studying fluorescence spectroscopy on protein
Yin Yanxia,Xiang Benqiong,Tong Li(College of Life Science,Beijing Normal University,Beijing 100875,China)Fluorescence spectroscopy is very important for studying protein structure and conformation changes.The concept and principle of fluorescence spectroscopy are introduced at first,then the application of studying fluorescence spectroscopy on protein is explained.
[Downloads: 5,407 ] [Citations: 270 ] [Reads: 1096 ] HTML PDF Cite this article
The CNC machine tool with systematic work process and its application of teaching design
Li Yanxian(Department of Mechanical and Electronic Engineering,Nanjing Communications Institute of Technology,Nanjing 211188,China)According to professional training objectives and the main jobs of the structure of vocational skills and knowledge required to "CNC machine tools and spare parts" for the carrier,taking the CNC programming and operation of capacity-building as the center,this paper shows the design of the "knowledge of CNC machine tools,observation and analysis of CNC lathes,CNC milling machine to observe and analyze the processing center,programming and processing stepped shaft,threaded shaft of the programming and processing,hand wheel slot programming and processing,convex programming and processing of the template,the base of the programming and processing"of 9 items,25 learning environment,67 tasks,and one of the "convex template programming and processing" learning environment for the teaching unit design.
[Downloads: 383,514 ] [Citations: 7 ] [Reads: 140 ] HTML PDF Cite this article
Study on the design and analysis methods of orthogonal experiment
Liu Ruijiang,Zhang Yewang,Wen Chongwei,Tang Jian(School of Pharmaceutics,Jiangsu University,Zhenjiang 212013,China)The importance of orthogonal experimental design and analysis is introduced briefly.The principle and characteristic are expounded.The design methods of orthogonal experiment and analysis methods of orthogonal experimental results are analyzed in detail,which afford fully systemic methods for orthogonal experimental design and analysis.Problems in orthogonal experimental design and analysis and development of software for orthogonal experimental design and analysis are also pointed out in the end.
[Downloads: 55,855 ] [Citations: 3,448 ] [Reads: 1044 ] HTML PDF Cite this article
Construction and actualization of new experimental teaching system for chemical specialty
YANG Jin-tian(Institute of Life Science,Huzhou Normal College,Huzhou 313000,China)The new system of chemical experiment teaching is constructed,and the comprehensive experiments,open experiments and research-oriented experiments are set up to improve the degree of source sharing,the efficiency of using equipment and the quality of experimental teaching,hence efficiently optimizing the practical abilities and fostering innovative spirit for the undergraduates are achieved.
[Downloads: 24,313 ] [Citations: 11 ] [Reads: 1082 ] HTML PDF Cite this article
Research on statistical analyses and countermeasures of 100 laboratory accidents
Li Zhihong;Training Department,Kunming Fire Command School;This paper summarizes 100typical cases of laboratory accidents from 2001and analyzes the cases in fields of accident type,accident link,accident cause,dangerous substance category,etc.The result shows as follows:the fire disasters and explosive accidents are the main types of laboratory accidents;the dangerous chemicals,instruments and equipment,and pressure vessels are main dangerous substances;the instruments and equipment and reagent application processes are the main links of accidents;the violation of rules,improper operation,carelessness,wire short circuit and aging are the main reasons of accidents.It also puts forward the countermeasures and suggestions for the prevention and control of laboratory accidents in the following aspects:establishing complete safety management system,actively promoting standard construction of laboratory safety,strengthening laboratory safety education and training,and formulating and improving emergency plans for laboratory accidents.
[Downloads: 10,651 ] [Citations: 568 ] [Reads: 130 ] HTML PDF Cite this article
Practice and thinking of education of“College Students' Innovative and Entrepreneurial Training Program”based on tutor system
Qian Xiaoming;Rong Huawei;Qian Jingzhu;Office of Academic Affairs,Nanjing University of Technology;The innovation and entrepreneurship education has been included in the teaching and education program of college schools."College Students' Innovative and Entrepreneurship Training Program "has become an"Excellent Program"as one of the most important reform tasks in Ministry of Education.The tutor system is an effective way of innovative education and pilot training for both college schools and students.Students learn the method of innovation researches and technique of entrepreneurial process through the program.In the meanwhile,teachers in college schools find a new stage to improve their teaching ability.This article focuses on the project,practice and feasibility of the"College Students' Innovative and Entrepreneurial Training Program "under the tutor system.
[Downloads: 10,109 ] [Citations: 225 ] [Reads: 1072 ] HTML PDF Cite this article