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Journal of Hydrodynamics 2024年第5期36卷 803-816页

作者： Wen-xin huai Xiao-hua Zhang Dan Li zhong-hua Yang Yi-dan Ai State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China

A coastal forest combined with a backward-facing step is an efficient facility to reduce tsunami damage to residential areas behind sea *** study establishes a generalized model,and experimentally explores the water level changes upstream of the vegetation-step mitigation model as well as its energy dissipation effect under different initial Froude numbers,step heights,and vegetation *** results show that the relative backwater rise increases with the growth of vegetation density,patch length and initial Froude number,representing a slowing down of the tsunami *** for energy dissipation,it is mainly caused by the additional resistance of the vegetation and the hydraulic *** the vegetation condition not only affects the energy dissipation due to stem-scale turbulence within the patch,but also changes the hydraulic jump process of water falling from the step in cooperation with the step *** a result,the energy dissipation efficiency always increases with the growth of vegetation density,vegetation patch length and step *** the criterion that the energy dissipation efficiency and its growth rate can hardly change with vegetation parameters,this study innovatively defines the threshold slope and gives the principle of judging the most cost-effective vegetation conditions at different step *** results are expected to provide an important reference for the design of composite tsunami mitigation facilities.

关键词： Vegetation-step model step height backwater rise energy dissipation

LARGE EDDY SIMULATION OF OPEN CHANNEL FLOWS WITH NONSUBMERGED VEGETATION

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Journal of Hydrodynamics 2011年第2期23卷 258-264页

作者： huai Wen-xin WU Zhen-lei QIAN zhong-dong GENG Chuan State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China

Results of several Large Eddy Simulations （LES） this article. It is shown that the vegetation can make the flow of open channel flows with non-submerged vegetation are presented in structure in the mainstream direction uniform for both supercritical and subcritical flows. For subcritical flows, the LES results of the ensemble-average of time-averaged velocity distributions at four vertical sections around a single plant are in good agreement with measurements. The velocity sees double peaks at the upper and lower positions of flows. For supercritical flows, the ensemble-average velocities see some discrepancy between LES and measurement results. Some secondary flow eddies appear near the single plant, and they just locate in the positions of the double peaks in stream-wise velocity profiles. It is also found that the vegetation drag coefficient deceases as the Froude number increases.

关键词： non-submerged sub/supercritical flow peak value Large Eddy Simulation (LES) secondary flow drag coefficient

典型交叉连接形式的承插式埋地管线地震响应分析

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岩土工程学报 2025年第2期47卷 407-416页

作者：侯本伟刘嘉伟张亚波韩俊艳钟紫蓝杜修力北京工业大学城市与工程安全减灾教育部重点实验室北京100124

埋地管线的接口类型以及管线交叉连接形式,对管线结构地震响应造成较大影响。由于管线交叉处的受力和变形特征受到各分肢管线结构类型的影响,首先建立分肢直线型管线有限元模型,分析了地震波作用下柔性接口球墨铸铁管线(DIP)和刚性接口... 详细信息

埋地管线的接口类型以及管线交叉连接形式,对管线结构地震响应造成较大影响。由于管线交叉处的受力和变形特征受到各分肢管线结构类型的影响,首先建立分肢直线型管线有限元模型,分析了地震波作用下柔性接口球墨铸铁管线(DIP)和刚性接口灰口铸铁管线(CIP)的接口张开量以及管土相对变位;然后分析了采用十字型、T型、L型和双T型交叉管件连接的管线地震响应特征,其中交叉管件与各分肢管线分别采用承插式和法兰式两种连接口,并比较了接口类型对各类交叉管件地震响应的影响规律。结果表明:对于地震波作用下不同接口类型的直线型管线,DIP柔性接口峰值张开量大于CIP刚性接口,CIP刚性接口管线轴力远大于DIP柔性接口管线。管线交叉处采用承插式接口时,双T型交叉管件连接的管线接口峰值张开量略小于十字型、T型连接。管线交叉处采用法兰接口时,与法兰口邻接的DIP柔性接口张开量较大、易发生拉伸破坏,与法兰口邻接的CIP刚性接口轴向压力较大、易发生受压破坏;在双T型交叉处,与法兰口邻接的承插接口响应显著大于十字型、T型连接。

关键词：埋地管线交叉管线地震波动承插式接口法兰接口接口变形

Data-driven Nonparametric Model Adaptive Precision Control for Linear Servo Systems

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International Journal of Automation and computing 2014年第5期11卷 517-526页

作者： Rong-Min Cao zhong-Sheng hou Hui-Xing Zhou School of Automation Beijing Information Science & Technology University Advanced Control Systems Laboratory Beijing Jiaotong University College of Engineering China Agricultural University

Nowadays, high-precision motion controls are needed in modern manufacturing industry. A data-driven nonparametric model adaptive control(NMAC) method is proposed in this paper to control the position of a linear servo system. The controller design requires no information about the structure of linear servo system, and it is based on the estimation and forecasting of the pseudo-partial derivatives(PPD) which are estimated according to the voltage input and position output of the linear motor. The characteristics and operational mechanism of the permanent magnet synchronous linear motor(PMSLM) are introduced, and the proposed nonparametric model control strategy has been compared with the classic proportional-integral-derivative(PID) control algorithm. Several real-time experiments on the motion control system incorporating a permanent magnet synchronous linear motor showed that the nonparametric model adaptive control method improved the system s response to disturbances and its position-tracking precision, even for a nonlinear system with incompletely known dynamic characteristics.

关键词： Data-driven control nonparametric model adaptive control precision motion control permanent magnet synchronous linear motor robustness

PC12 cell integrated biosensing neuron devices for evaluating neuronal exocytosis function upon silver nanoparticles exposure

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Science China Chemistry 2015年第10期58卷 1600-1604页

作者： Pratikkumar Shah Qiaoli Yue Xuena Zhu Fangcheng Xu huai-Sheng Wang Chen-zhong Li College of Chemistry and Chemical Engineering Liaocheng University Nanobioengineering/Bioelectronics Laboratory Department of Biomedical Engineering Florida International University Department of Chemical and Biochemical Engineering College of Chemical Engineering Xiamen University

In this research, we explored a rapid assessment of silver nanoparticles(Ag-NPs) neurotoxicity at a single-cell level. Traditional nanotoxicity assays on large cell-populations may hide the important heterogeneity of individual cells often found in neuronal cells. The development in the area of new nanomaterial discoveries is far ahead of the development of advanced tools to measure these materials' toxicity. Development of alternative approaches to assess nanomaterials toxicity rapidly, reliably, and accurately is desirable. Here, we present a chip-based, cell-integrated microwell-array device for rapid assessment of neurotoxicity of Ag-NPs by monitoring the exocytosis function of a PC12 cell. Results presented here confirm the dose-dependent toxicity of Ag-NPs and the immediate alteration of their exocytosis function when exposed to NPs.

关键词： neuron devices nanotoxicity amperometry exocytosis PC12 silver nanoparticle

Study on the influence mechanism of ambient humidity on the temperature rise of decay-like composite insulators

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High Voltage 2022年第5期7卷 916-924页

作者： Zheng zhong Yuan Chen Yunpeng Liu Sizu hou Jianghai Geng Hebei Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power UniversityBaodingChina High Voltage Technology Institute North China Electric Power Research InstituteBeijingChina Hebei Key Laboratory of Power Internet of Things Technology North China Electric Power UniversityBaodingChina

At present,observing the temperature rise of composite insulators is an effective method for the detection of decay-like ***,ambient humidity will affect the temperature rise of composite insulators,which will cause problems in screening the decaylike composite ***,it is urgent to study the temperature rise principle of decay-like insulators and find out the influence mechanism of humidity on temperature *** this study,a four-electrode system is designed to measure the surface current,volume current and interface current of the decay-like short sample and the intact short sample under different *** the equivalent circuit models of short samples and the 500 kV full-size decay-like composite insulator are built to analyse the contribution rates of leakage conductance loss and polarisation loss to temperature *** results show that the contribution rates of the polarisation loss to the temperature rise of two samples are 35.8%and 23.6%in low humidity,while they are 98.3%and 64.4%in high *** the full-size decay-like composite insulator,the contribution rates of polarisation loss to its temperature rise in high or low humidity are more than 99%.In addition,the proportion of polarisation loss increases at first and then decreases with the increase of the length of the decay-like *** conclusions of this study provide a theoretical basis for further understanding the corresponding relationship between decaylike defects and temperature rise and improve the detection rate of decay-like insulators.

关键词： composite ambient humidity

A present-day tectonic stress map for eastern Asia region

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Acta Seismologica Sinica(English Edition) 2001年第5期14卷 524-533页

作者： XU zhong-huai 1. Institute of Geophysics China Seismological Bureau 100081 Beijing China

Based on the data of earthquake centroid moment tensor (CMT) solution, P-wave first motion focal mechanism solution and deep hole breakouts, a present-day tectonic stress map for eastern Asia region is compiled. The original stress data are smoothed for every 200 km × 200 km area by taking the average of all stress indicators within each sub-region. The stress map shows the spatial distribution of the orientation of principal stress axes and the stress regimes. An earthquake focal mechanism map for the eastern Asia is also given. The maps of orientation of principal stress axes show that, apart from the strong influence of the collision between the Indian Ocean plate and Eurasian plate, the present-day tectonic stress in eastern Asia is significantly affected by the back-arc extension of the subduction zones. The joint effect of the continental collision at the Himalaya arc and back-arc extension in the Burma arc region may be responsible for the remarkable rotation of the principal stress orientations in southeastern part of the Tibet plateau. The joint action of the collision between the Philippine Sea plate and Eurasian plate at Taiwan Island and the back-arc extension of the Ryukyu arc affect the stress field in eastern part of China. There are no strong earthquakes in the present day in the vast back-arc region of the Java trench subduction zone. The back-arc extension there may create a condition favorable to the southward flow of the lithosphere material in southeastern Asia. In the inner part of the Tibet plateau region, roughly demarcated by the Kunlun mountain, the northern and northeastern part is a broad intracontinental compressive zone, while the southern and southwestern part is generally in a normal-faulting stress state.

关键词： tectonic stress eastern Asia stress map

PermissibleWind Conditions for Optimal Dynamic Soaring with a Small Unmanned Aerial Vehicle

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Computer Modeling in Engineering & Sciences 2016年第6期111卷 531-565页

作者： Liu Duo-Neng hou zhong-Xi Guo Zheng Yang Xi-Xiang Gao Xian-zhong College of Aerospace Sciences and Engineering National University of Defense TechnologyChangshaHunan410073China

Dynamic soaring is a flight maneuver to exploit gradient wind field to extend endurance and traveling *** trajectories for permissible wind conditions are generated for loitering dynamic soaring as well as for traveling patterns with a small unmanned aerial *** efficient direct collection approach based on the Runge-Kutta integrator is used to solve the optimization *** fast convergence of the optimization process leads to the potential for real-time *** on the results of trajectory optimizations,the general permissible wind conditions which involve the allowable power law exponents and feasible reference wind strengths supporting dynamic soaring are *** the smallest allowable wingtip clearance to trade for robustness and safety of the vehicle system and improving the maximum traveling speed results in shrunken permissible domain of wind conditions for loitering and traveling dynamic soaring *** analyses of vehicle model parameters show that properly reducing the wingspan and increasing the maximum lift-to-drag ratio and the wing loading can enlarge the permissible *** domains for different traveling directions show that the downwind dynamic soaring benefitting from the drift is more efficient than the upwind traveling pattern in terms of permissible domain size and net traveling speed.

关键词： Dynamic soaring Permissible wind conditions Trajectory optimization Unmanned aerial vehicle(UAV)

Diet,food availability,and climatic factors drive ranging behavior in white-headed langurs in the limestone forests of Guangxi,southwest China

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Zoological Research 2021年第4期42卷 406-411页

作者： Ke-Chu Zhang Qi-Hai Zhou huai-Liang Xu zhong-Hao Huang College of Life Science Sichuan Agricultural UniversityYa’anSichuan 625014China Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection(Guangxi Normal University) Ministry of EducationGuilinGuangxi 541004China Guangxi Key Laboratory of Rare and Endangered Animal Ecology Guangxi Normal UniversityGuilinGuangxi 541004China

Changes in abiotic and biotic factors can affect the efficiency of biological systems in animals,forcing them to adjust their behaviors in response to daily and seasonal *** September 2016 to August 2017,we collected ranging behavior data on four groups of white-headed langurs(Trachypithecus leucocephalus)in the Guangxi Chongzuo White-Headed Langur National Nature Reserve,Guangxi,southwest *** simultaneously analyzed how multiple ecological factors affect langur ranging behavior,which should facilitate our understanding of the potential mechanisms underlying their adaptation to limestone *** showed that langur ranging behavior was significantly affected by diet composition,food availability,and climatic ***,moving time and daily path length increased with the increase in dietary ***,moving time and daily path length were positively associated with the availability of fruit and relative humidity of the forest,and moderately associated with temperature and relative humidity of bare *** study demonstrated that langurs maintain stable moving and feeding times and exhibit a short daily travel distance,likely adopting an energy-conserving behavioral strategy in response to food shortages and high temperatures in the fragmented karst *** results highlight the importance of food availability and temperature in shaping the ranging behavior of these karst-dwelling primates.

关键词： behavior white karst

Effect of lower bainite/martensite/retained austenite triplex microstructure on the mechanical properties of a low-carbon steel with quenching and partitioning process

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 303-313页

作者： Wan-song Li Hong-ye Gao zhong-yi Li Hideharu Nakashima Satoshi Hata Wen-huai Tian School of Materials Science and Engineering University of Science and Technology Beijing Interdisciplinary Graduate School of Engineering Sciences Kyushu University

We present a study concerning Fe-0. 176C-1.31Si-1.58Mn-0.26Al-0.3Cr （wt%） steel subjected to a quenching and partitioning （Q＆P） process. The results of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and tensile tests demon- strate that the microstructures primarily consist of lath martensite, retained austenite, lower bainite （LB）, and a small amount of tempered martensite; moreover, few twin austenite grains were observed. In the microstrucmre, three types of retained austenite with different sizes and morphologies were observed： blocky retained austenite （-300 nm in width）, film-like retained austenite （80-120 nm in width）, and ul- tra-fine film-like retained austenite （30-40 nm in width）. Because of the effect of the retained austenite/martensite/LB triplex microstructure, the specimens prepared using different quenching temperatures exhibit high ultimate tensile strength and yield strength. Furthermore, the strength effect of LB can partially counteract the decreasing strength effect of martensite. The formation of LB substantially reduces the amount of retained austenite. Analyses of the retained austenite and the amount of blocky retained austenite indicated that the carbon content is critical to the total elongation of Q＆P steel.

关键词： low-carbon steel quenching partitioning retained austenite rnicrostructure mechanical properties