检索结果-南通市图书馆

Crack mechanism of ground fissures in loess layer of Fenwei Basin, China

Journal of Mountain Science 2024年第5期21卷 1683-1696页

作者： li Cong LU Quanzhong WANG Feiyong luo Wenchao XU Qiang School of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of EducationXi’an 710054China Observation and Research Station of Ground Fissure and Land Subsidence Ministry of Natural ResourcesXi’an 710054China School of Engineering and Technology China University of GeosciencesBeijing 100083China

The Fenwei Basin, covered by loess, experiences severe ground fissure disasters. These disasters disrupt the continuity of the loess and pose significant threats to engineering construction safety along transportation routes. Nevertheless, the crack characteristics and the influence zone of ground fissures in the loess layer remain inadequately investigated. To effectively prevent and control ground fissure disasters, physical model tests and the PFC(particle flow code) numerical simulation method are used to investigate the crack mechanism of buried ground fissures in the loess layer. The results show that there are two main cracks in the layer profile, which have a Y-shape morphology. As the dip angle of the preset cracks increased from 60° to 90°, the main deformation zone at the surface gradually shifted towards the footwall. The process of crack propagation from depth to surface is divided into five stages. Additionally, the results confirm the accuracy of the width of the rupture zone d2in the footwall calculated by the cantilever beam theory. These findings can offer theoretical guidance for determining the avoidance distance of ground fissures in loess regions, as well as for implementing disaster prevention and corresponding control measures for various stages of buried ground fissure propagation.

关键词： Ground fissure Fenwei Basin Physical model test Particle flow code Crack propagation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pannexins in the musculoskeletal system:new targets for development and disease progression

引用

Bone Research 2024年第2期12卷 255-269页

作者： Yan luo Shengyuan Zheng Wenfeng Xiao Hang Zhang Yusheng li Department of Orthopedics Xiangya HospitalCentral South UniversityChangshaHunan 410008China National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan 410008China Department of Clinical Medicine Xiangya Medicine SchoolCentral South UniversityChangshaHunan 410008China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

During cell differentiation,growth,and development,cells can respond to extracellular stimuli through communication ***(Panx)family and connexin(Cx)family are two important types of channel-forming *** family contains three members(Panx1-3)and is expressed widely in bone,cartilage and *** there is no sequence homology between Panx family and Cx family,they exhibit similar configurations and *** to Cxs,the key roles of Panxs in the maintenance of physiological functions of the musculoskeletal system and disease progression were gradually revealed ***,we seek to elucidate the structure of Panxs and their roles in regulating processes such as osteogenesis,chondrogenesis,and muscle *** also focus on the comparison between Cx and *** a new key target,Panxs expression imbalance and dysfunction in muscle and the therapeutic potentials of Panxs in joint diseases are also discussed.

关键词： skeletal diseases system

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental Study on the Electrochemical Performance of PEMFC under Different Assembly Forces

引用

Chinese Journal of Mechanical Engineering 2024年第3期37卷 265-274页

作者： Tongze Su Jiaran liu Yanqiang Wei Yihuizi li Weichao luo Jinzhu Tan Nanjing Tech University Nanjing 211816China

Proton exchange membrane fuel cell(PEMFC)is of paramount significance to the development of clean *** components of PEMFC are assembled using many pairs of nuts and *** assembly champing bolt torque is critical to the electrochemical performance and mechanical stability of *** this paper,a PEMFC with the threechannel serpentine flow field was used and *** different assembly clamping bolt torques were applied to the PEMFC in three uniform assembly bolt torque and six non-uniform assembly bolt torque conditions,*** then,the electrochemical performance experiments were performed to study the effect of the assembly bolt torque on the electrochemical *** test results show that the assembly bolt torque significantly affected the electrochemical performance of the *** uniform assembly bolt torque conditions,the maximal power density increased initially as the assembly bolt torque increased,and then decreased on further increasing the assembly *** existed the optimum assembly torque which was found to be 3.0 N·m in this *** non-uniform assembly clamping bolt torque conditions,the optimum electrochemical performance appeared in the condition where the assembly torque of each bolt was closer to be 3.0 N·*** could be due to the change of the contact resistance between the gas diffusion layer and bipolar plate and mass transport resistance for the hydrogen and oxygen towards the catalyst *** work could optimize the assembly force conditions and provide useful information for the practical PEMFC stack assembly.

关键词： Proton exchange membrane fuel cell Assembly force Experiment Electrochemical performance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Energy-saving design and optimization of pressure-swing-assisted ternary heterogenous azeotropic distillations

引用

Chinese Journal of Chemical Engineering 2024年第4期68卷 1-7页

作者： lianjie Wu Kun Lu Qirui li lianghua Xu Yiqing luo Xigang Yuan Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion College of Chemical and Chemical EngineeringTianjin University of TechnologyTianjin 300384China State Key Laboratory of Chemical Engineering Tianjin UniversityTianjin 300072China

A huge amount of energy is always consumed to separate the ternary azeotropic mixtures by *** heterogeneous azeotropic distillation and the pressure-swing distillation are two kinds of effective technologies to separate heterogeneous azeotropes without entrainer *** give better play to the synergistic energy-saving effect of these two processes,a novel pressure-swing-assisted ternary heterogeneous azeotropic distillation(THAD)process is proposed *** this process,the ternary heterogeneous azeotrope is decanted into two liquid phases before being refluxed into the azeotropic distillation column to avoid the aqueous phase remixing,and three columns'pressures are modified to decrease the flowrates of the recycle *** the dividing wall column and heat integration technologies are introduced to further reduce its energy consumption,and the pressureswing-assisted ternary heterogeneous azeotropic dividing-wall column and its heat integration structure are achieved.A genetic algorithm procedure is used to optimize the proposed *** design results show that the proposed processes have higher energy efficiencies and lower CO_(2)emissions than the published THAD process.

关键词： Distillation Separation Process control Process systems

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Injection of a Self-propelled Polymer into a Small Circular Cavity

引用

Chinese Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang Yan-li Zhou Xiao Yang Fan Wu Meng-Bo luo Department of Physics Taizhou UniversityTaizhou318000China Department of Physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An improved positioning model of deep-seafloor datum point at large incidence angle

引用

Journal of Oceanology and limnology 2024年第1期42卷 90-100页

作者： Qianqian li Shoulian CAO Fanlin YANG Yu luo Qian TONG College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150000China College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Ocean Geomatics Ministry of Natural ResourcesQingdao 266590China

The inhomogeneous sound speed in seawater causes refraction of sound waves,and the elimination of the refraction effect is essential to the accuracy of underwater acoustic *** raytracing method is an indispensable tool for effectively handling ***,this method has a conflict between localization accuracy and computational *** equivalent sound speed profile(ESSP)method uses a simple sound speed profile(SSP)instead of the actual complex SSP,which can improve positioning precision but with residual *** residual error is especially non-negligible in deep water and at large beam incidence *** analyzing the residual error of the ESSP method through a simulation,an empirical formula of error is *** data collected in the sailing circle mode(large incidence angle)of the South China Sea are used for *** experiments show that compared to the ESSP method,the improved algorithm has higher positioning precision and is more efficient than the ray-tracing method.

关键词： underwater acoustic positioning seafloor datum points large incident angle equivalent sound speed profile(ESSP) deep water

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Robust multi-sensor image matching based on normalized self-similarity region descriptor

引用

Chinese Journal of Aeronautics 2024年第1期37卷 271-286页

作者： Xuecong liU Xichao TENG Jing luo Zhang li Qifeng YU Yijie BIAN College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China High-Tech Institute Qingzhou 262500China

Multi-modal image matching is crucial in aerospace applications because it can fully exploit the complementary and valuable information contained in the amount and diversity of remote sensing ***,it remains a challenging task due to significant non-linear radiometric,geometric differences,and noise across different *** improve the performance of heterologous image matching,this paper proposes a normalized self-similarity region descriptor to extract consistent structural *** first construct the pointwise self-similarity region descriptor based on the Euclidean distance between adjacent image blocks to reflect the structural properties of multi-modal ***,a linear normalization approach is used to form Modality Independent Region Descriptor(MIRD),which can effectively distinguish structural features such as points,lines,corners,and flat between multi-modal *** further improve the matching accuracy,the included angle cosine similarity metric is adopted to exploit the directional vector information of multi-dimensional feature *** experimental results show that the proposed MIRD has better matching accuracy and robustness for various multi-modal image matching than the state-of-the-art *** can effectively extract consistent geometric structure features and suppress the influence of SAR speckle noise using non-local neighboring image blocks operation,effectively applied to various multi-modal image matching.

关键词： Remote sensing Multi-modal image matching Template matching Feature descriptor Similarity metric Synthetic Aperture Radar(SAR)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Causal temporal graph attention network for fault diagnosis of chemical processes

引用

Chinese Journal of Chemical Engineering 2024年第6期70卷 20-32页

作者： Jiaojiao luo Zhehao Jin Heping Jin Qian li Xu Ji Yiyang Dai School of Chemical Engineering Sichuan UniversityChengdu 610065China China Three Gorges Corporation Beijing 100038China

Fault detection and diagnosis(FDD)plays a significant role in ensuring the safety and stability of chemical *** the development of artificial intelligence(AI)and big data technologies,data-driven approaches with excellent performance are widely used for FDD in chemical ***,improved predictive accuracy has often been achieved through increased model complexity,which turns models into black-box methods and causes uncertainty regarding their *** this study,a causal temporal graph attention network(CTGAN)is proposed for fault diagnosis of chemical processes.A chemical causal graph is built by causal inference to represent the propagation path of *** attention mechanism and chemical causal graph were combined to help us notice the key variables relating to fault *** in the Tennessee Eastman(TE)process and the green ammonia(GA)process showed that CTGAN achieved high performance and good explainability.

关键词： Chemical processes Safety Fault diagnosis Causal discovery Attention mechanism Explainability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prediction of the thermal conductivity of Mg–Al–La alloys by CALPHAD method

引用

International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 129-137页

作者： Hongxia li Wenjun Xu Yufei Zhang Shenglan Yang lijun Zhang Bin liu Qun luo Qian li State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al *** accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high thermal ***,databases for predicting temperature-and composition-dependent thermal conductivities must be *** this study,Mg-Al-La alloys with different contents of Al2La,Al3La,and Al11La3phases and solid solubility of Al in the α-Mg phase were *** influence of the second phase(s) and Al solid solubility on thermal conductivity was *** results revealed a second phase transformation from Al_(2)La to Al_(3)La and further to Al_(11)La_(3)with the increasing Al content at a constant La *** degree of the negative effect of the second phase(s) on thermal diffusivity followed the sequence of Al2La>Al3La>Al_(11)La_(3).Compared with the second phase,an increase in the solid solubility of Al in α-Mg remarkably reduced the thermal *** the basis of the experimental data,a database of the reciprocal thermal diffusivity of the Mg-Al-La system was established by calculation of the phase diagram (CALPHAD)*** a standard error of±1.2 W/(m·K),the predicted results were in good agreement with the experimental *** established database can be used to design Mg-Al alloys with high thermal conductivity and provide valuable guidance for expanding their application prospects.

关键词： magnesium alloy thermal conductivity thermodynamic calculations materials computation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of Local Climate Zones on the Urban Heat and Dry Islands in Beijing:Spatial Heterogeneity and Relative Contributions

引用

Journal of Meteorological Research 2024年第1期38卷 126-137页

作者： Zuofang ZHENG Fu luo Nana li Hua GAO Yuanjian YANG Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089 School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Key Laboratory of Urban Meteorology China Meteorological AdministrationBeijing 100089

Based on the building height and density data on a 100-m resolution,hourly 2-m temperature and humidity data at83 automatic weather stations,and gridded local climate zone(LCZ)data on a 120-m resolution in urban Beijing in2020,this study first employs the semivariogram combined with building parameters to calculate spatial correlations and has identified an LCZ grid resolution of 500 m suitable for best usage of the available observation ***,how the spatially heterogeneous LCZs affect and contribute to the canopy urban heat island intensity(UHII)and urban dry island intensity(UDII)are quantitatively *** is found that UHII is high in winter and low in summer with a unimodal diurnal variation while UDI is low in winter but high in summer with a bimodal diurnal *** LCZ with compact mid-rise(open high-rise)buildings exhibits the highest UHII(UDII),followed by the compact high-rise(compact low-rise),while the LCZ of scattered trees presents both the lowest UHII and the lowest *** most significant difference in the UHII(UDII)among the nine LCZ types in the urban area of Beijing is2.62℃(1.1 g kg^(-1)).Area-weighted averaging analysis reveals that the open mid-rise LCZ is the most significant contributor to the UHII(UDII),immediately followed by compact mid-rise(open low-rise),with the least contribution from bare rock or paved(scattered trees).The results also indicate that beyond the intrinsic physical properties of the LCZs of a city,their area proportions cannot be overlooked in evaluating their impact on the UHI and *** quantitatively findings could help urban planners to create a livable urban climate and environment by adjusting the relevant land use.

关键词： local climate zone(LCZ) urban heat island(UHI) urban dry island(UDI) distribution pattern contribution rate Beijing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：