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research on rock crack contact model considering linked substances based on particle flow method

International Journal of Mining science and Technology 2025年第4期35卷 553-571页

作者： Fukun Xiao Kai Xie Lei Shan Gang Liu Lianchong Li Fedotova Iuliia Heilongjiang Ground Pressure&Gas Control in Deep Mining Key Lab Heilongjiang University of Science and TechnologyHarbin 150022China School of Safety Engineering Heilongjiang University of Science and TechnologyHarbin 150022China School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China Khabarovsk Federal Research Center of the Far Eastern Branch of the Russian Academy of Sciences Khabarovsk 68000Russia

The models constructed by particle flow simulation method can effectively simulate the heterogeneous substance characteristics and failure behaviors of ***,existing contact models overlook the rock cracks,and the various simulation methods that do consider cracks still exhibit certain *** this paper,based on Flat-Joint model and Linear Parallel Bond model,a crack contact model considering linked substance in the crack is proposed by splitting the crack contact into two portions:linked portion and unlinked portion for *** new contact model considers the influence of crack closure on the contact force-displacement *** a better compressive tensile strength ratio(UCS/T)was obtained by limiting the failure of the contact bond to be solely controlled by the contact force and moment of the linked ***,by employing the FISH Model tool within the Particle Flow Code,the contact model was constructed and verified through contact force–displacement experiments and loading-unloading tests with cracked ***,the contact model was tested through simulations of rock mechanics *** results indicate that the contact model can effectively simulate the axial and lateral strain laws of rocks simultaneously and has a relatively good reproduction of the bi-modularity of rocks.

关键词： Crack closure Contact model Compaction stage Initial effective modulus Lateral strain

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Effect of Free-End Torsion on the Corrosion and Mechanical Properties for Mg-3Zn-0.2Ca Alloy

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Acta Metallurgica Sinica(English Letters) 2025年第1期38卷 59-70页

作者： Li-Lan Gao Jiang Ma Yan-Song Tan Xiao-Hao Sun Qi-Jun Gao De-Bao Liu Chun-Qiu Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin300384China School of Materials Science and Engineering Tianjin University of TechnologyTianjin300384China

Magnesium alloys with excellent degradability and biocompatibility are promising materials for biomedical implants,saving patients the burden of second ***,their mechanical properties and corrosion resistance are significantly below the requirements for implant *** study aims to improve the mechanical and corrosion resistance properties of Mg-3Zn-0.2Ca alloy by pre-torsion treatment,and find out the optimal shear *** rod-shaped Mg-3Zn-0.2Ca alloy specimens were pre-torsion treated at different torsion *** effect of free-end torsion on Mg-3Zn-0.2Ca alloy was characterized through microstructure analysis,mechanical testing,and corrosion ***-torsion treatment can refine grain and induce twins and dislocations in Mg-3Zn-0.2Ca *** surface hardness increases with the increase in torsion *** yield strength and ultimate strength initially increase and then decrease with increasing torsion angle,while ductility decreases with increasing torsion *** with a shear strain of 30%exhibit the highest tensile strength,reaching 284.78±10.62 MPa,with an elongation of 19.37±1.66%.Furthermore,they show a significant improvement in fatigue lives both before and after *** the stress amplitude is 120 MPa,the fatigue lives for specimens without pre-torsion treatment are 54,275 cycles and 4324 cycles before and after pre-corrosion,while they increased significantly to 92,015 cycles and 5050 cycles with the 30%shear strain,***,the 30%shear strain specimens show a significant reduction in corrosion *** conclusion,pre-torsion treatment can effectively modify the microstructure of Mg-3Zn-0.2Ca alloy,enhancing both mechanical properties and corrosion *** optimal shear strain for this improvement is 30%.This study provides a practical method to enhance the mechanical properties and corrosion resistance of Mg-3Zn-0.2Ca alloy,making it more suitable for biomedical implan

关键词： Magnesium alloy Pre-torsion Microstructure Mechanical property Corrosion resistance

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Energy-Free Sensing and Context Recognition Using Photovoltaic Cells

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IEEE Sensors Journal 2025年第9期25卷 15598-15611页

作者： Shintani, Kaede Rizk, Hamada Yamaguchi, Hirozumi Osaka University Graduate School of Information Science and Technology Department of Information Networking Suita565-0871 Japan Tanta University Tanta31733 Egypt RIKEN Center for Computational Science Kobe650-0047 Japan RIKEN Center for Computational Science Department of Computer and Control Engineering Kobe650-0047 Japan

The field of energy-free sensing and context recognition has recently gained significant attention as it allows operating systems without external power sources. Photovoltaic cells can convert light energy into electrical energy to power sensing devices, but their power may not be sufficient to ensure energy-free sensing due to the varying power needs of sensors and high computational demands. In this article, we propose the use of photovoltaic cells as a standalone sensor for the recognition of different contexts, including user identification, step counting, and location tracking. The system utilizes the photocurrent readings generated by the photovoltaic cells to capture the unique mobility patterns of different users. By analyzing these patterns, the system can accurately identify the user, count the number of steps taken, and track the user’s location. We propose a computationally efficient dynamic time warping (DTW) to match the variable length sequences of photocurrent readings to a database of known patterns and identify the closest subject and location matches. The system was rigorously evaluated in a realistic environment, and the results indicate that it can accurately estimate step count, identify subjects, and localize them with an accuracy of 88%, 90%, and 43 cm, respectively. This is achieved while the proposed system is nonintrusive and can operate without external power sources, making it a promising technology for energy-free sensing and context recognition. © 2001-2012 IEEE.

关键词： Photovoltaics

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P-tuned FeN_(2)binuclear sites for boosted CO_(2)electro-reduction

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Journal of Energy Chemistry 2025年第2期101卷 816-824,I0018页

作者： Cao Guo Sanshuang Gao Jun Li Menglin Zhou Abdukader Abdukayum Qingquan Kong Yingtang Zhou Guangzhi Hu School of Materials and Energy Institute for Ecological Research and Pollution Control of Plateau LakesSchool of Ecology and Environmental ScienceYunnan UniversityKunming 650504YunnanChina Xinjiang Key Laboratory of Novel Functional Materials Chemistry College of Chemistry and Environmental SciencesKashi UniversityKashi 844000XinjiangChina School of Mechanical Engineering Chengdu UniversityChengdu 610106SichuanChina National Engineering Research Center for Marine Aquaculture Marine Science and Technology CollegeZhejiang Ocean UniversityZhoushan 316004ZhejiangChina

The recycling of CO_(2)through electrochemical processes offers a promising solution for alleviating the greenhouse effect;however,the activation of CO_(2)and desorption of^(*)CO in electrocatalytic CO_(2)reduction(ECR)frequently encounter high energy barriers and competitive hydrogen evolution reactions(HERs),which are urgent problems that need to be *** this study,a catalyst(P100-Fe-N/C)with homogeneous P-tuned FeN_(2)binuclear sites(N_(2)PFe-FePN_(2))was successfully synthesised,demonstrating satisfactory performance in the ECR to CO.P100-Fe-N/C attains a peak FECOof 98.01%and a normalized TOF of 664.7 h-1at-0.7 VRHE,surpassing the performance of the Fe binuclear catalyst without P and singleatoms *** the MEA cell,a FECOexceeding 90%can still be *** functional theory analysis indicates that the asymmetric coordination configuration induced by the incorporation of P facilitates a reduction in the system's *** modulation of P results in the d-band centre of the catalyst being positioned closer to the Fermi level,which facilitates the interaction of the catalyst with CO_(2),allowing more electrons to be injected into the CO_(2)molecule at the Fe binuclear sites and inhibiting the *** P-tuned FeN_(2)binuclear sites effectively lower the^(*)CO desorption barrier.

关键词： Electrocatalysis Diatomic catalyst Heteroatom doping CO_(2)reduction reaction DFT calculation

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A synchronous spatiotemporal graph neural network for short-term traffic flow prediction

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Soft Computing 2025年第6期29卷 2983-2997页

作者： Zhang, Zhao Jiao, Xiaohong Engineering Research Center of the Ministry of Education for Intelligent Control System and Intelligent Equipment Yanshan University Qinhuangdao066004 China School of Electrical Engineering Yanshan University Qinhuangdao066004 China

Traffic flow prediction is a vital part of an intelligent traffic management system. The critical challenge of the traffic flow prediction task is to fully use observable historical information to extract the hidden spatiotemporal dependence. For this reason, a synchronous spatiotemporal grammar graph attention network is proposed based on multi-dimensional edge information (MDEI-SSTGGAT) to achieve short-term traffic flow prediction tasks. In the designed model, the spatial nodes are first clustered. Then, a local spatiotemporal graph is established for each category for extracting synchronous spatiotemporal features. In the feature extraction module, the graph attention network with multi-dimensional edge information captures the spatiotemporal features dynamically, and the grammar graph structure fuses the hidden features of three observable traffic parameters. The model fully uses observable traffic parameter features to improve the prediction accuracy while keeping the computation time short. Simulation results on real data sets show that the prediction performance of this model is better than the existing prediction methods. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Traffic control

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Fluorescence sensor based on IFE between AEP@UCNPs and oxTMB for the determination of Cd^(2+)in paddy rice combined with HRP enzyme inhibition mechanism

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Food science and Human Wellness 2025年第1期14卷 154-160页

作者： Haizhen Ding Shuai Hou Siqi Zhao Liping Guo Ao Sun Qiuhui Hu Leiqing Pan Qiang Liu Chao Ding Collaborative Innovation Center for Modern Grain Circulation and Safety Key Laboratory of Grains and Oils Quality Control and ProcessingCollege of Food Science and EngineeringNanjing University of Finance and EconomicsNanjing 210023China College of Food Science and Technology Nanjing Agricultural UniversityNanjing 210095China

Cadmium ion(Cd^(2+))detection technology plays a prominent role in food safety and human ***,we designed and constructed an 2-aminoethyl dihydrogen phosphate(AEP)@upconversion nanoparticles(UCNPs)fluorescence sensor for quantitative detection of Cd^(2+)in paddy rice based on inner filter effect(IFE)combined with enzyme inhibition *** AEP modification UCNPs can offer a stable fluorescence donor at 658 nm and be quenched by the oxidized tetramethylbenzidine(oxTMB)catalyzed by horseradish peroxidase(HRP)*** addition of Cd^(2+),the fluorescence of AEP@UCNPs fluorescence sensor was weaken due to the IFE between AEP@UCNPs and *** addition of Cd^(2+),HRP enzyme activity was inhibited by Cd^(2+),leading to the decreased oxTMB,resulting in the enhance upconversion fluorescence *** a result,the fluorescence intensity signal at 658 nm of the IFE-based AEP@UCNPs fluorescence sensor increased linearly with the increase in Cd^(2+)in a wide range from 0.5μmol/L to 6μmol/L and the limit of detection(LOD)was 24.6 n mol/*** addition,our proposed IFE-based AEP@UCNPs fluorescence sensor can achieve Cd^(2+)detection in paddy rice in 30 min.

关键词： Paddy rice Cd^(2+) Enzyme inhibition Upconversion nanoparticles(UCNPs) Inner filter effect(IFE)

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research on Low-Temperature Pull and Deflection Characteristics of Aerospace Power Supply 11th

Research on Low-Temperature Pull and Deflection Characterist...

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11th Frontier Academic Forum of Electrical engineering, FAFEE 2024

作者： Zhang, Yuhuan Liu, Mi Guo, Chuanwei Ma, Tao zhao, Chuang Li, Xinxin Chen, Yonggang Li, Yan Beijing Spacecrafts Beijing100094 China Beijing Space Power Conversion and Control Engineering and Technology Research Center Beijing100094 China

ISBN: (纸本)9789819788316

Deep space exploration is an important field of space exploration and astronautical activities in today's world, which is of great significance to the development of human civilization. Aerospace power supply system is an important part of the power supply system for deep space exploration, so research on its low-temperature pull and deflection characteristics is particularly important. In this paper, the low-temperature pull-off characteristics of the Aerospace Power Supply are verified and enhanced. Firstly, the application circuit of VDMOS, which is the core component of aerospace power supply, is analyzed, and two different working modes, namely, single switching application and high frequency switching application, are summarized. Secondly, the low-temperature pull-off test of aerospace power supply is carried out to compare and analyze with the normal temperature pull-off test to identify the reasons for poor low-temperature pull-off characteristics.. Finally, the low-temperature pull-off control link is analyzed, and the solution is given and verified through the test, which improves the low-temperature pull-off characteristics of the astronautical power supply, and contributes to the development of high reliability of the power supply system for deep space exploration. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Space research

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Simultaneous immobilization of multiple heavy metal(loid)s in contaminated water and alkaline soil inoculated Fe/Mn oxidizing bacterium

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Journal of Environmental sciences 2025年第1期147卷 370-381页

作者： Yi Wu Shengli Wang Jun Xu Fei Zang Song Long Yining Wu Yuqing Wang Zhongren Nan Technology Research Center for Pollution Control and Remediation of Northwest Soil and Groundwater College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China State Key Laboratory of Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730000China

Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were *** surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II)and Mn(II)by Pseudomonas taiwanensis(marked as P4)and Pseudomonas plecoglossicida(marked as G1)contains rich reactive oxygen functional groups,which play critical roles in the removal efficiency and immobilization of heavymetal(loid)s in co-contamination *** isolated strains P4 and G1 can growwell in the following environments:pH 5-9,NaCl 0-4%,and temperature 20-30℃.The removal efficiencies of Fe,Pb,As,Zn,Cd,Cu,and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system(the initial concentrations of heavy metal(loid)were 1 mg/L),approximately reaching 96%,92%,85%,67%,70%,54%and 15%,*** exchangeable and carbonate bound As,Cd,Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil,thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)*** research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s.

关键词： Bio-Fe/Mn oxides Pseudomonas Heavy metal(loid)s Removal and immobilization

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High potential in synergizing the reduction of dissolved organic carbon concentration and carbon dioxide emissions for submerged-vegetationcovered river networks

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Journal of Environmental sciences 2025年第5期151卷 298-309页

作者： Qingqian Li Ruixia Liu Zhangmu Jing Yanjie Wei Shengqiang Tu Huibin Yu Hongjie Gao Peng Yuan State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental ScienceBeijing 100012China State Environmental Protection Key Laboratory of Estuarine and Coastal Environment Chinese Research Academy of Environmental ScienceBeijing 100012China State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China College of Municipal and Environmental Engineering Shenyang Jianzhu UniversityShenyang 110168China

Various technologies and projects have been explored and developed for the synergetic control of environmental pollution and carbon emissions in aquatic *** submerged vegetation in shallow waters was also expected to achieve this ***,the magnitude and mechanism of carbon dioxide(CO_(2))emission affected by submerged vegetation is not clear enough in complex aquatic *** study investigated the influences of submerged plants on CO_(2)emission,ecosystem metabolism features,and microbial community traits based on observations in river networks on the Changjiang River *** results showed that CO_(2)emission from planted waters accounted for 73%of unplanted ***,planted waters had higher dissolved organic carbon removal capacity in overlying water and higher potential of carbon sequestration in sediment at the same *** distinctions between the two habitats were attributed to(1)improved CO_(2)and bicarbonate consumption in water columns via enhancing photosynthesis and(2)inhibited CO_(2)production by reconstructing the benthic microbial *** eco-advantages were found in planted sediments,such as a high potential of methane oxidation and xenobiotics biodegradation and a low risk of becoming black and *** brief,submerged vegetation is beneficial in promoting pollution removal and carbon retention *** study advances our understanding of the feedback between aquatic metabolism and CO_(2)emission.

关键词： Mitigated CO_(2)emission Submerged vegetation Paired O_(2)-CO_(2)departure Carbon uptake velocity Microbial metabolism pathways The Changjiang River

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Construction of nitrogen and phosphorus flux of land-based pond mariculture: Taking the Xiangshan Bay as an example

HydroResearch

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Hydroresearch 2025年 8卷 286-293页

作者： Du, Yiwei Li, Xiaoguang Liu, Siru Lin, Tian College of Oceanography and Ecological Science Shanghai Ocean University Shanghai 201306 China Basin Research Center for Water Pollution Control Chinese Research Academy of Environmental Sciences Beijing 100012 China

The construction of nutrient flux can provide a scientific basis for understanding the fate in the aquaculture systems to facilitate sustainable coastal environment management. In this study, the tailwater of the mariculture pond from 65 sampling points in the Xiangshan Bay were measured. The average concentrations of total nitrogen and total phosphorus of the samples were 2.16 mg/L and 0.11 mg/L, which were lower than Category I of Mariculture Tailwater Discharge Standards of Zhejiang Province. Two methods were applied to estimate the discharge flux of the total nitrogen and total phosphorus from mariculture ponds in the Xiangshan Bay. The application of chemical analysis method was technically optimized by means of area data obtained by high-density sampling campaign and GIS method. It was estimated that the annual discharge flux of total nitrogen and total phosphorus via chemical analysis method were 271.2–338.9 tones and 7.6–9.5 tones, respectively. Potential environmental effects were further assessed according to monthly discharge flux combined with seasonal variations of hydrodynamic environment. In comparison, the estimated annual fluxes of chemical analysis method were much lower than the ones of pollution discharging coefficient method which were 357.56 tones/year and 22.00 tones/year, respectively. It is considered that part of nitrogen and phosphorus nutrients deposited into the bottom sediment of the ponds or coastal environment. The continuous loading of nitrogen and phosphorus nutrients into sediment can increase the risk of secondary release, especially in such semi-enclosed bay. © 2025

关键词： Chemical analysis method Environmental impact Fluxes The Xiangshan Bay Total nitrogen and total phosphorus

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