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Self-reinforced Calcium Phosphate Cement Inspired by Sea Cucumber Dermis

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 682-688页

作者：吴治文 WANG Zihao CAI Zepeng qu Liting 于涛 College of Chemistry and Materials Science Jinan UniversityGuangzhou 510632China Guangdong Provincial Key Laboratory of Spine and Spinal Cord Reconstruction The Fifth Affiliated Hospital(Heyuan Shenhe People’s Hospital)Jinan UniversityHeyuan 517000China

A composite bone cement based onα-TCP with self-reinforcing characteristics is prepared by compounding cellulose whiskers and polyvinyl alcohol in different *** this system,we are inspired by the sea cucumber,which can alter the stiffness of their inner dermis *** the formation of hydrogen bonds between the hydroxyl groups on the cellulose whiskers and PVA,the bone cement matrix can be strengthened during the curing process of *** the process of bone cement blending,there is more water,the hydrogen bond connection is destroyed,so the slurry has better fluidity at this *** the hydration of the bone cement progresses,the reduction of the water phase leads to the formation of a permeable network structure of hydrogen bond connections between the *** dual-phase action of PVA and whiskers greatly increases the mechanical strength of the bone cement system(5.5 to 23.8 MPa),while the presence of polyvinyl alcohol improves the toughness of the bone cement *** work was supposed to explore whether the chemoresponsive materials can be adapted to biomedical materials,for example,bone repair.

关键词： bone repair self-reinforce chemoresponsive hydrogen bond

An object detection approach with residual feature fusion and second-order term attention mechanism

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 411-424页

作者： Cuijin Li Zhong qu Shengye Wang College of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqingChina College of Electronic Information Chongqing Institute of EngineeringChongqingChina

Automatically detecting and locating remote occlusion small objects from the images of complex traffic environments is a valuable and challenging *** the boundary box location is not sufficiently accurate and it is difficult to distinguish overlapping and occluded objects,the authors propose a network model with a second-order term attention mechanism and occlusion ***,the backbone network is built on *** a method is designed for the feature extraction network based on an item-wise attention mechanism,which uses the filtered weighted feature vector to replace the original residual fusion and adds a second-order term to reduce the information loss in the process of fusion and accelerate the convergence of the ***,an objected occlusion regression loss function is studied to reduce the problems of missed detections caused by dense *** experimental results demonstrate that the authors’method achieved state-of-the-art performance without reducing the detection *** mAP@.5 of the method is 85.8%on the Foggy_cityscapes dataset and the mAP@.5 of the method is 97.8%on the KITTI dataset.

关键词： artificial intelligence computer vision image processing machine learning neural network object recognition

A refined deviatoric hardening plastic model for sand

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2813-2821页

作者： Min Wang Tongming qu Yuntian Feng Teng Liang Liangtong Zhan MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou310058China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyKowloon999077Hong KongChina Zienkiewicz Centre for Computational Engineering College of EngineeringSwansea UniversitySwanseaWalesSA18EPUK Center for Hypergravity Experimental and Interdisciplinary Research Zhejiang UniversityHangzhou310058China

The classical deviatoric hardening models are capable of characterizing the mechanical response of granular materials for a broad range of degrees of *** work finds that it has limitations in accurately predicting the volumetric deformation characteristics under a wide range of confining/consolidation *** issue stems from the pressure independent hardening law in the classical deviatoric hardening *** overcome this problem,we propose a refined deviatoric hardening model in which a pressure-dependent hardening law is developed based on experimental *** between numerical results and laboratory triaxial tests indicate that the improved model succeeds in capturing the volumetric deformation behavior under various confining/consolidation pressure conditions for both dense and loose ***,to examine the importance of the improved deviatoric hardening model,it is combined with the bounding surface plasticity theory to investigate the mechanical response of loose sand under complex cyclic loadings and different initial consolidation *** is proved that the proposed pressure-dependent deviatoric hardening law is capable of predicting the volumetric deformation characteristics to a satisfactory degree and plays an important role in the simulation of complex deformations for granular geomaterials.

关键词： Elasto-plastic deformation Isotropic hardening Deviatoric plastic strain Granular material Kinematic hardening Bounding surface

Analysis of Extended Fisher-Kolmogorov Equation in 2D Utilizing the Generalized Finite Difference Method with Supplementary Nodes

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CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES 2024年第1期141卷 267-280页

作者： Ju, Bingrui Sun, Wenxiang qu, Wenzhen Gu, Yan Changan Univ Key Lab Rd Construct Technol & Equipment MOE Xian 710018 Peoples R China Qingdao Univ Sch Math & Stat Qingdao 266071 Peoples R China

In this study, we propose an efficient numerical framework to attain the solution of the extended Fisher-Kolmogorov (EFK) problem. The temporal derivative in the EFK equation is approximated by utilizing the Crank-Nicolson scheme. Following temporal discretization, the generalized finite difference method (GFDM) with supplementary nodes is utilized to address the nonlinear boundary value problems at each time node. These supplementary nodes are distributed along the boundary to match the number of boundary nodes. By incorporating supplementary nodes, the resulting nonlinear algebraic equations can effectively satisfy the governing equation and boundary conditions of the EFK equation. To demonstrate the efficacy of our approach, we present three numerical examples showcasing its performance in solving this nonlinear problem.

关键词： Generalized finite difference method nonlinear extended Fisher-Kolmogorov equation Crank-Nicolson scheme HEAT-CONDUCTION FUNDAMENTAL-SOLUTIONS LOCALIZED METHOD ELEMENT-METHOD SCHEME DIFFUSION

Mobility of rhenium and selenium during chemical weathering and their implication for petrogenic organic carbon oxidation

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Science China Earth Sciences 2024年第3期67卷 740-750页

作者： Yuhong ZHANG Jin WANG Yuanxin qu Chao ZHU Zhangdong JIN State Key Laboratory of Loess and quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China University of Chinese Academy of Sciences Beijing 100049China Xi'an Institute for Innovative Earth Environment Research Xi'an 710061China Institute of Global Environmental Change Xi'an Jiaotong UniversityXi'an 710049China

The oxidative weathering of petrogenic organic carbon(OC_(petro)) is an important source of carbon dioxide(CO_(2)) into the atmosphere on geological timescales and significantly influences the carbon cycle and global climate change. However, at present, a robust proxy to assess OC_(petro)oxidation is lacking. Riverine rhenium(Re) has emerged as a potential proxy to trace OC_(petro)oxidation, but little is known about Re sources and its relationship with OC_(petro)oxidation. To better understand the robustness of this proxy, we analyzed a shale weathering profile from the early Cambrian Shuijingtuo Formation in Chengkou County, Chongqing City, to address the mobility of Re and selenium(Se) and their relationship with the oxidation of OC_(petro)by analyses of the elemental variation and sequential extraction. The results showed that the chemical index of alteration(CIA)increases from the fresh bedrock to the weathered sections, indicating enhanced weathering intensity. Based on the sequential extraction and mass transfer coefficients(τ), Re and Se mainly exist in the organic phase of shale and are paired lost with OC_(petro) during weathering, with no obvious correlation with sulfide minerals. Furthermore, the different proportions of Re and Se loss with OC_(petro) loss can be attributed to their different geochemical behaviors during weathering. Our study supports Re as a robust proxy to trace OC_(petro) oxidation, whereas Se is the potential one. In the future, combined studies on various sedimentary rock profiles with catchment basins are needed to determine the sources of riverine Re and Se and their relationships with OC_(petro) oxidation.

关键词： Rhenium and selenium Shale Mobility OC_(petro) Chemical weathering

Earthquake potential across the North–South seismic belt of China

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Science Bulletin 2024年第2期69卷 179-182页

作者： Yanchuan Li Xinjian Shan Chunyan qu Guohong Zhang Xiaogang Song State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

The elastic rebound theory,which frames our understanding of earthquakes,suggests that the accumulated elastic strain on faults will ultimately be released through earthquakes[1].As such,identifying the location,rate,and accumulation of slip deficit on faults constitutes a basis for seismic potential assessment[2].Interseismic coupling(ISC)refers to the ratio of the slip deficit rate on a fault to the far-field loading rate,where full and no coupling correspond to 100%and 0%slip deficits,respectively.

关键词： seismic belt fault

Comparison of life cycle assessment of large-scale biogas projects with different raw materials in China

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 268-279页

作者： Jiazheng Sun Youpei qu Xiaoyi Lyu Xinjie Ding Xinying Miao Mukesh Kumar Awasthi Jingbo qu School of Energy and Environment City University of Hong KongHong Kong 999077China College of Engineering Northeast Agricultural UniversityHarbin 150030China Key Laboratory of Agricultural Renewable Resources Utilization Technology and Equipment in Cold Areas of Heilongjiang Province Harbin 150030China College of Natural Resources and Environment Northwest A&F UniversityYangling 712100Shaanxi China

The anaerobic digestion(AD)disposal of stover and cattle manure is of great significance to the development of low-carbon economy and green energy in China,but it will also have an impact on the environment,and the degree of influence is different for various raw *** this study,life cycle assessment(LCA)methods were applied to analyze and compare the impact of corn stovers biogas projects(CSBP)and dairy manure biogas projects(DMBP)on the environment during the whole operation *** results of inventory analysis were evaluated by ReCiPe2016 Hierarchy(H)mid-point(problem-oriented)and end-point(destruction-oriented)method,*** results showed that the net energy efficiency of CSBP was higher(763.903 kW·h/FU)and the greenhouse gas(GHG)emission reduction of DMBP was more(5541.418 kg CO_(2)-eq/FU).The anaerobic digestion(AD)units have the greatest environmental impacts,and human carcinogenic toxicity is the largest environmental impact category(1.16-1.43 PE).The key to reducing environmental impact is reducing the input of chemical substances and the waste of electric *** CSBP and DMBP have a favorable impact on ecosystem quality and resources,and CSBP is more beneficial to the environment(-10.297 Pt).Co-digestion is an important measure to reduce the environmental damage from biogas *** research results provide theoretical support for the selection of raw materials for large-scale biogas projects in China,provide technical basis for reducing the impact of actual operation on the environment,and promote the resource utilization of agricultural waste and carbon dioxide emission reduction and sequestration.

关键词： life cycle assessment environmental impact assessment large-scale biogas projects bioenergy carbon dioxide emission reduction

Fault Analysis on AES:A Property-Based Verification Perspective

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Tsinghua Science and Technology 2024年第2期29卷 576-588页

作者： Xiaojie Dai Xingxin Wang Xue qu Baolei Mao Wei Hu School of Cybersecurity Northwestern Polytechnical UniversityXi’an 710072China School of Cyber Science and Engineering Zhengzhou UniversityZhengzhou 450001China

Fault analysis is a frequently used side-channel attack for ***,existing fault attack methods usually involve complex fault fusion analysis or computation-intensive statistical analysis of massive fault *** this work,we take a property-based formal verification approach to fault *** derive fine-grained formal models for automatic fault propagation and fusion,which establish a mathematical foundation for precise measurement and formal reasoning of fault *** extract the correlations in fault effects in order to create properties for fault *** further propose a method for key recovery,by formally checking when the extracted properties can be satisfied with partial keys as the search *** results using both unprotected and masked advanced encryption standard(AES)implementations show that our method has a key search complexity of 216,which only requires two correct and faulty ciphertext pairs to determine the secret key,and does not assume knowledge about fault location or pattern.

关键词： side-channel attack fault analysis fault propagation model property extraction fault verification

Digitalizing river aquatic ecosystems

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Journal of Environmental Sciences 2024年第3期137卷 677-680页

作者： Yaohui Bai Hui Lin Chenchen Wang Qiaojuan Wang Jiuhui qu Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China School of Environmental and Municipal Engineering Tianjin Chengjian UniversityTianjin 300384China Center for Water and Ecology Tsinghua UniversityBeijing 100084China

Traditional river health assessment relies on limited water quality indices and representative organism activity,but does not comprehensively obtain biotic and abiotic information of the ***,we propose a new approach to evaluate the ecological and health risks of river aquatic ***,detailed physicochemical and biological characterization of a river ecosystem can be obtained through pollutant determination(especially emerging pollutants)and DNA/RNA ***,supervised machine learning can be applied to perform classification analysis of characterization data and ascertain river ecosystem ecology and *** proposed methodology transforms river ecosystem health assessment and can be applied in river management.

关键词： Digitalizing River ecosystem health Emerging pollutants High throughput sequencing Machine learning