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Dynamics Analysis of a Parallel Mill-turn Tool Spindle Head Driven by Dual-linear Motors Using Extended Transfer Matrix Method

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Chinese Journal of Mechanical Engineering 2011年第5期24卷 859-869页

作者： wu wenjing liu qiang School of Mechanical Engineering and Automation Beihang University Beijing 100191

The hybrid dynamics of multi-rigid-body and multi-flexible-body system becomes the mainstream of multi-body *** there lacks a compact approach to model the hybrid dynamics,especially in modern machine tool application,due to the difficulty of solving the hybrid equations or the limitation of current software when dealing with the hybrid *** extended transfer matrix method（E-TMM）,which extends elements in three-dimensional space with higher matrixes,is proposed to simplify the modeling process of the hybrid *** E-TMM modeling approaches of 3 basic elements including 3D vibrant rigid body,joint and flexible body are studied in details.A parallel mill-turn tool spindle head unit driven by dual-linear motors is chosen as a plant to demonstrate the E-TMM modeling *** using E-TMM,the spindle head unit is simplified as a topological network consisting of the three types of element,i.e.,3D vibrant rigid body,joint and flexible body,including 11 rigid bodies,14 joints and 1 3D-Timoshenko *** the dynamic model of the system can be easily obtained by deducing the element-network by means of state vector *** dynamic characteristics of the spindle head,such as natural frequencies,dynamic flexibility,*** be predicted by solving the obtained *** verification indicates that the E-TMM is valid with enough accuracy in the dynamic analysis of the parallel mill-turn tool spindle *** E-TMM is capable of modeling the dynamics of machine tool structure with no requirements of deducing and solving the sophisticated differential ***,the E-TMM provides a simple and elegant tool for hybrid dynamic analysis in future dynamic design of machine tools.

关键词： NC machine tools dynamics modeling transfer matrix method(TMM)

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Improving Multi-task GNNs for Molecular Property Prediction via Missing Label Imputation

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Machine Intelligence Research 2025年第1期22卷 131-144页

作者： Fenyu Hu Dingshuo Chen qiang liu Shu wu University of Chinese Academy of Sciences Beijing100190China Center for Research on Intelligent Perception and Computing State Key Laboratory of Multimodal Artificial Intelligence SystemsInstitute of AutomationChinese Academy of SciencesBeijing100190China

The prediction of molecular properties is a fundamental task in the field of drug ***,graph neural networks(GNNs)have been gaining prominence in this *** a molecule tends to have multiple correlated properties,there is a great need to develop the multi-task learning ability of ***,limited by expensive and time-consuming human annotations,collecting complete labels for each task is *** a result,most existing benchmarks involve many missing labels in training data,and the performance of GNNs is impaired due to the lack of sufficient supervision *** overcome this obstacle,we propose to improve multi-task molecular property prediction by missing label ***,a bipartite graph is first introduced to model the molecule-task co-occurrence ***,the imputation of missing labels is transformed into predicting missing edges on this bipartite *** predict the missing edges,a graph neural network is devised,which can learn the complex molecule-task co-occurrence *** that,we select reliable pseudo labels according to the uncertainty of the prediction *** with enough and reliable supervision information,our approach achieves state-of-the-art performance on a variety of real-world datasets.

关键词： Graph classification imbalance learning prediction bias mixture of experts multiview representations

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Droughts and windstorms due to climate change increase variability in species and trait composition of a subtropical monsoon evergreen broadleaf forest in China

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FOREST ECOSYSTEMS 2025年第1期12卷 11-19页

作者： Chen, wenjing liu, Lei liu, Daijun Penuelas, Josep Zhou, Guoyi Yu, Zhen wu, Anchi wu, Zhurong Hua, Langqin Nanjing Univ Informat Sci & Technol Sch Ecol & Appl Meteorol Nanjing 210044 Peoples R China Univ Vienna Dept Bot & Biodivers Res Rennweg 14 A-1030 Vienna Austria CSIC Global Ecol Unit CREAF UAB Barcelona 08193 Catalonia Spain CREAF Barcelona 08193 Catalonia Spain Nanjing Univ Informat Sci & Technol Inst Ecol Sch Ecol & Appl Meteorol Nanjing 210044 Peoples R China Nanjing Univ Informat Sci & Technol Key Lab Ecosyst Carbon Source & Sink China Meteorol Adm ECSS CMA Nanjing 210044 Peoples R China Hubei Minzu Univ Hubei Key Lab Biol Resources Protect & Utilizat Enshi 445000 Peoples R China

Background Climate change is accelerating alterations in forest species and community composition worldwide, especially following extreme events like severe droughts and windstorms. Understanding these effects on subtropical forests is crucial for conservation and forest management, but it remains unclear whether the impacts are stochastic or deterministic. Methods We analyzed a unique dataset from a 1-ha permanent plot in a subtropical monsoon broadleaf evergreen forest in China, monitored over 26 years with six surveys from 1994 to 2020. The forest has been free from anthropogenic disturbances for over 400 years. In each survey, we measured all trees with a diameter at breast height (DBH) >= 1 cm, and recorded 11 plant functional traits relating to photosynthesis, wood properties, water use, and nutrient dynamics. Using this data, we calculated species and trait dispersion, assessing short-term (similar to 5 years) and long-term (26 years) trends in species and trait composition following severe droughts and windstorm events. Results Severe droughts, and subsequent droughts, increased both species and trait dispersion, while species composition converged, and trait dispersion remained relatively stable throughout the recovery period. Windstorm events led to increased species dispersion but decreased trait dispersion. We observed a clear directional shift in both species and trait composition under these climatic stressors, with a more pronounced increase in trait dispersion compared to species dispersion. Conclusion In the short term (similar to 5 years), severe droughts and windstorms increased species composition divergence, while trait composition responses varied. Over 26 years, deterministic processes mainly drove community composition changes, especially for trait composition, although stochastic processes also played a role. These findings suggest enhancing forest resilience to climatic stressors by protecting adaptive species or increasing species diversit

关键词： Community dynamics Functional traits Community composition Deterministic processes Climate change

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A review of over-discharge protection through prelithiation in working lithium-ion batteries

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Journal of Energy Chemistry 2025年第2期101卷 437-452页

作者： Hanchen Wang Yingtian liu Mingze Jiang qiang Zhang School of Aerospace Engineering National Engineering Research Center of Neuromodulation Tsinghua University Tsinghua Center for Green Chemical Engineering Electrification Department of Chemical Engineering Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Tsinghua University

The demand for high safety and high reliability lithium-ion batteries(LIBs) is strongly considered for practical ***,due to their inherent self-discharge properties or abuse,LIBs face the threat of over-discharge,which induces premature end of life and increased risk of thermal *** addition,a strong demand for batteries with zero-volt storage is strongly considered for aerospace and implantable medical *** this review,we firstly introduce the necessity and the importance of over-discharge and zero-volt protection for *** mechanism of damage to the Cu current collectors and SEI induced by potential changes during over-discharge is *** current over-discharge protection strategies based on whether the zero-crossing potential of the electrodes is ***,the fresh insights into the material design of cathode prelithiation additives are presented from the perspective of over-discharge protection.

关键词： Electrode potential regulation Electrode prelithiation Li-ion batteries Over-discharge protection Zero-volt storage

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A vascular endothelial growth factor–loaded chitosan-hyaluronic acid hydrogel scaffold enhances the therapeutic effect of adipose-derived stem cells in the context of stroke

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Neural Regeneration Research 2025年第12期20卷 3591-3605页

作者： Zhijian Zheng Xiaohui Lin Zijun Zhao qiang Lin Ji liu Manli Chen Wenwen wu Zhiyun wu Nan liu Hongbin Chen Department of Neurology Fujian Medical University Union HospitalFuzhouFujian ProvinceChina Department of Rehabilitation Fujian Medical University Union HospitalFuzhouFujian ProvinceChina Fujian Key Laboratory of Molecular Neurology Fujian Medical UniversityFuzhouFujian ProvinceChina Institute of Clinical Neurology Fujian Medical UniversityFuzhouFujian ProvinceChina

Adipose-derived stem cell,one type of mesenchymal stem cells,is a promising approach in treating ischemia-reperfusion injury caused by occlusion of the middle cerebral ***,its application has been limited by the complexities of the ischemic *** scaffolds,which are composed of hyaluronic acid and chitosan,exhibit excellent biocompatibility and biodegradability,making them promising candidates as cell *** endothelial growth factor is a crucial regulatory factor for stem *** hyaluronic acid and chitosan have the potential to make the microenvironment more hospitable to transplanted stem cells,thereby enhancing the therapeutic effect of mesenchymal stem cell transplantation in the context of ***,we found that vascular endothelial growth factor significantly improved the activity and paracrine function of adipose-derived stem ***,we developed a chitosan-hyaluronic acid hydrogel scaffold that incorporated vascular endothelial growth factor and first injected the scaffold into an animal model of cerebral ischemiareperfusion *** loaded with adipose-derived stem cells,this vascular endothelial growth factor–loaded scaffold markedly reduced neuronal apoptosis caused by oxygen-glucose deprivation/reoxygenation and substantially restored mitochondrial membrane potential and axon *** in vivo experiments revealed that this vascular endothelial growth factor–loaded hydrogel scaffold facilitated the transplantation of adipose-derived stem cells,leading to a reduction in infarct volume and neuronal apoptosis in a rat model of stroke induced by transient middle cerebral artery *** also helped maintain mitochondrial integrity and axonal morphology,greatly improving rat motor function and ***,utilizing a hydrogel scaffold loaded with vascular endothelial growth factor as a stem cell delivery system can mitigate the adverse effects of ischemic microenvironment

关键词： adipose-derived stem cells chitosan hyaluronic acid hydrogel ischemia-reperfusion oxygen-glucose deprivation/reoxygenation stroke transient middle cerebral artery occlusion transplantation vascular endothelial growth factor

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Distributions and risk assessment of heavy metals in solid waste in lead-zinc mining areas and across the soil, water body, sediment and agricultural product ecosystem in their surrounding areas

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China Geology 2025年第1期8卷 92-106页

作者： Zhi-qiang wu Hai-ying Li liu-yan Lü Guo-jun Liang Ting-ting wu Jiang-xia Zhu No.117 Geological Team Bureau of Geology and Mineral Exploration and Development of Guizhou ProvinceGuiyang 550023China Ecological Environment Monitoring Center of Guizhou Province Guiyang 550023China Guizhou Institute of Geological Survey Guiyang 550081China Environmental Engineering Assessment Center of Anshun City Anshun 561000China Environmental Emergency Center of Anshun City Anshun 561000China

To identify the root causes of heavy metal contamination in soils as well as prevent and control such contamination from its sources,this study explored the accumulation patterns and ecological risks of heavy metals like Cd and Pb in solid waste in mining areas and across the water body,sediment,soil and agricultural product ecosystem surrounding the mining *** on the residual solid waste samples in lead-zinc deposits in a certain area of Guizhou Province,along with samples of topsoils,irrigation water,river sediments,and crops from surrounding *** study analyzed the distributions of eight heavy metals,i.e.,Cd,As,Cr,Hg,Pb,Zn,Cu,and Ni,in the samples through field surveys and sample ***,this study assessed the contamination levels and ecological risks of heavy metals in soils,sediments,and agricultural products using methods such as the single-factor index,Nemerow composite index,and potential ecological risk *** results indicate that heavy metals in the solid waste samples all exhibited concentrations exceeding their risk screening values,with 60%greater than their risk intervention *** soils and sediments demonstrate slight and moderate comprehensive ecological risks of heavy *** single-factor potential ecological risks of heavy metals in both the soil and sediment samples decreased in the order of Hg,Cd,Pb,As,Cu,Zn,Cr,and Ni,suggesting the same sources of heavy metals in the soils and *** of the agricultural product samples exhibited over-limit concentrations of heavy metals dominated by Cd,Pb,Ni,and Cr,excluding Hg and *** agricultural product assessment using the Nemerow composite index reveals that 35%of the agricultural product samples reached the heavy metal contamination level,implying that the agricultural products from farmland around the solid waste dumps have been contaminated with heavy *** eight heavy metals in the soil,sediment,and agricultural product samples manifested hig

关键词： Lead-zinc mining area Solid waste Soil Water body Sediment Agricultural product Nemerow composite index Cd,Pb,Ni,Cr elements Heavy metal contamination Ecological risk assessment Coefficients of variation(CVs) Environmental restoration engineering

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Obesogenic effects of six classes of emerging contaminants

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Journal of Environmental Sciences 2025年第5期151卷 252-272页

作者： Siying wu Chaoyu Tong Jing liu MOE Key Laboratory of Environmental Remediation and Ecosystem Health College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China

There is growing concern about the concept that exposure to environmental chemicals may be contributing to the obesity ***,there is no consensus on the obesogenic effects of emerging contaminants from a toxicological and environmental *** potential human exposure and experimental evidence for obesogenic effects of emerging contaminants need to be systematically *** main objective of this review is to provide recommendations for further subsequent policy development following a critical analysis of the literature for humans and experimental animals exposed to emerging *** article reviews human exposure to emerging contaminants(with a focus on antimicrobials,preservatives,water and oil repellents,flame retardants,antibiotics and bisphenols)and the impact of emerging contaminants on *** emerging contaminants have been widely detected in human biological *** studies provide evidence linking exposure to emerging contaminants to the risks of obesity in *** based on animalmodels and adipose cells show the obesogenic effects of emerging contaminants and identify modes of action by which contaminants may induce changes in body fat accumulation and lipid metabolic *** knowledge gaps in this area and future directions for further investigation are discussed.

关键词： Emerging contaminants Obesity Human exposure Preservatives Flame retardants Plasticizers Antibiotics

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Investigation of bubbles escape behavior from low basicity mold flux for high-Mn high-Al steels using 3D X-ray microscope

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 102-110页

作者： qiang liu Xiang Li Shen Du Ming Gao Yanbin Yin Jiongming Zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the *** which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid *** contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive ***,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding *** results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles *** addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually *** one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the *** findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.

关键词： mold flux low basicity bubbles three-dimensional X-ray microscope viscosity

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Characterization of petrophysical and seismic properties for CO2 storage with sensitivity analysis

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Petroleum Science 2025年第1期22卷 193-209页

作者： Yan-Jiao Dong Yi Shen Kai Guo Xiao-Qin wu qiang Mao Wen-Yue Sun Zhi-qiang Wang State Key Laboratory of Offshore Oil and Gas Exploitation Geosciences Department China University of Petroleum (East China) CNOOC Research Institute Ltd. School of Petroleum Engineering China University of Petroleum (East China)

Saline aquifers are considered as highly favored reservoirs for CO2sequestration due to their favorable properties. Understanding the impact of saline aquifer properties on the migration and distribution of CO2plume is crucial. This study focuses on four key parameters—permeability, porosity, formation pressure, and temperature—to characterize the reservoir and analyse the petrophysical and elastic response of CO2. First, we performed reservoir simulations to simulate CO2saturation, using multiple sets of these four parameters to examine their significance on CO2saturation and the plume migration ***, the effect of these parameters on the elastic properties is tested using rock physics *** established a relationship of compressional wave velocity（Vp） and quality factor（Qp） with the four key parameters, and conducted a sensitivity analysis to test their sensitivity to Vpand Qp. Finally, we utilized visco-acoustic wave equation simulated time-lapse seismic data based on the computed Vpand Qpmodels, and analysed the impact of CO2saturation changes on seismic data. As for the above numerical simulations and analysis, we conducted sensitivity analysis using both homogeneous and heterogeneous models. Consistent results are found between homogeneous and heterogeneous models. The permeability is the most sensitive parameter to the CO2saturation, while porosity emerges as the primary factor affecting both Qpand Vp. Both Qpand Vpincrease with the porosity, which contradicts the observations in gas reservoirs. The seismic simulations highlight significant variations in the seismic response to different parameters. We provided analysis for these observations, which serves as a valuable reference for comprehensive CO2integrity analysis, time-lapse monitoring, injection planning and site selection.

关键词： CO2 storage Time-lapse seismic CO2 plume Sensitivity analysis Rock physics Reservoir simulation Saline aquifer

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Recent development in electrode design for wide-temperature supercapacitors

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Science China Chemistry 2025年第1期68卷 96-117页

作者： Jianhong liu qiang Zhou Yuxiao Lin Xinsheng Zhao Guangmin Zhou Xiaoxiao Li School of Physics and Electronic Engineering Jiangsu Normal UniversityXuzhou 221116China Tsinghua-Berkeley Shenzhen Institute&Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China

An ever-increasing market demand has stimulated the soaring enthusiasm of researchers to develop wide-temperature supercapacitors(SCs).The active electrode is one of the most important parts of SC,which is directly related to the energy density,power transmission and long-term cyclability of the device in the wide-temperature *** with the SC electrodes aimed for room-temperature application,the SC electrodes for operating at wide-temperature scene often face greater *** this review,the main challenges of SC electrodes under various temperature conditions,including low,high and cross-fade temperatures,are *** relevant performance decay and failure mechanisms of wide-temperature SC electrodes are *** addition,this review deals with the recent studies and developments in robust wide-temperature SC electrodes with respect to the rational design of electrode structures and the exploitation of advanced active ***,the future directions for exploring reliable wide-temperature SCs are also proposed.

关键词： supercapacitor wide-temperature electrode design active materials

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