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云多租数据库资源规划调度技术综述

软件学报 2025年第1期36卷 446-468页

作者：刘海龙王硕侯舒峰徐海洋李战怀西北工业大学计算机学院大数据存储与管理工业和信息化部重点实验室(西北工业大学)

云多租数据库具有按需付费、按需扩展、免部署、高可用、自带运维能力、资源共享等诸多优势,可以大大降低用户使用数据库服务的成本.现在越来越多的企业和个人开始在数据库即服务(DaaS)平台托管他们的数据库服务. DaaS平台需要按照用户... 详细信息

云多租数据库具有按需付费、按需扩展、免部署、高可用、自带运维能力、资源共享等诸多优势,可以大大降低用户使用数据库服务的成本.现在越来越多的企业和个人开始在数据库即服务(DaaS)平台托管他们的数据库服务. DaaS平台需要按照用户服务水平协议(SLA)为诸多租户提供服务,同时也需要保障平台收益.但是,由于租户及其负载具有动态性、异构性和竞争性等特点,如何在遵循SLA的同时根据负载自适应规划调度资源同时兼顾平台收益对于DaaS平台来说是一件极具挑战性的工作.针对云多租数据库中比较常见的类型,如关系型数据库,详细分析了当前云多租数据库资源规划调度技术所面临的挑战,提炼了关键科学问题,给出了技术框架,然后从资源规划调度技术、资源预估技术、资源弹性伸缩技术以及数据库资源规划调度工具等4个方面对现有研究工作进行了总结和分析,并且展望了未来的研究方向.

关键词：多租户云数据库资源规划调度资源预估资源弹性伸缩关系数据库云原生多模数据库

A Method Based on Multi-Body Dynamic Analysis for A Floating Two-Stage Buffer Collision-Prevention System Under Ship Collision Loads

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China Ocean Engineering 2021年第6期35卷 828-840页

作者： LU Kai CHEN xu-jun YUAN Hui HUANG Heng WU Guang-huai College of Field Engineering Army Engineering University of PLANanjing 210007China School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing 211800China Nanjing Guangbo Engineering Technology Co.LTD Nanjing 210046China People’s Liberation Army of China 32184 Nanjing 211100China

The collision of ships poses a great threat to the piers in navigable *** kinetic energy of the moving ship can be consumed not only with the structural deformation,but also with tensile force from the proposed Floating Two-stage Buffer Collision-Prevention System(FTBCPS).The actual anti-collision effect of the current designed FTBCPS can be evaluated by the dynamic *** construction method of 3D model is introduced,and the system initial state is *** transformation matrix and the basic kinematics vector are given,and the system basic dynamics equation is then *** mechanical analysis on each component is carried out,and the detailed process of numerical simulation is also *** simulation results indicate that collision direction and collision position have a great influence on the system kinematic *** pier faces the greatest threat when a ship hits the floater on the front beam in a nearly vertical direction,or on the side beam in a larger course *** study shows that the current designed FTBCPS can make full use of the fracture tensile property of polyester ropes and keep the tensile force acted on pier within its bearable range at the same *** collision direction has a significant effect on the dynamic response of the colliding bodies,but no failure appeared in the simulations,which indicates that the current designed FTBCPS can protect bridge piers of all cases for the 5000-t ship with a velocity smaller than 5 m/s in navigable waters.

关键词： bridge engineering Floating Two-stage Buffer Collision-Prevention System dynamics response compression force anti-collision tensile force anti-collision

Study of Kinetic Characteristics for Drying Rice Husk

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Journal of Harbin Institute of Technology(New Series) 2013年第3期20卷 56-62页

作者： xu-Dong Chen huai-Bin Wang Ming Xie School of Energy Science and Engineering Harbin Institute of Technology

Rice husk (biomass fuel) samples have been dried in drying oven and a series of drying curve for illustrating moisture migration of rice husk have been obtained. It is first research for rice husk drying,and it can provide reference of fuel processing for different boilers which require rice husk with various water contents. In this paper,we apply Page equation to reflect the drying process and obtain drying characteristic curve,then analyze the drying law. Kinetic analysis of the results of moisture migration test has been done,after which, effective moisture diffusion coefficient,activation energy and drying kinetic equation of rice husk samples are obtained in test temperature range (80 - 130 ℃) . And these results show specific influence law of temperature for effective moisture diffusion coefficient.

关键词： rice husk drying characteristic curve effective moisture diffusion coefficient activation energy kinetic analysis

Rate Function of Large Deviation for a Class of Nonhomogeneous Markov Chains on Supercritical Percolation Network

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Acta Mathematica Sinica,English Series 2011年第9期27卷 1813-1830页

作者： zhong Hao xu Dong HAN School of Finance and Statistics East China Normal University Shanghai 200241 P. R. China Department of Mathematics Shanghai Jiao Tong University Shanghai 200240 P. R. China

We model an epidemic with a class of nonhomogeneous Markov chains on the supercritical percolation network on Zd. The large deviations law for the Markov chain is given. Explicit expression of the rate function for la... 详细信息

关键词： Nonhomogeneous Markov chain large deviation rate function percolation network

The Parabrachial Nucleus as a Key Regulator of Neuropathic Pain

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Neuroscience Bulletin 2021年第7期37卷 1079-1081页

作者： Zilong Wang Zhen-zhong xu Department of Anesthesiology Center for Translational Pain MedicineDuke University Medical CenterDurhamNC 27710USA SUSTech Center for Pain Medicine School of MedicineSouthern University of Science and TechnologyShenzhen 518055China Department of Neurobiology and Department of Anesthesiology of the First Affiliated Hospital NHC and CAMS Key Laboratory of Medical NeurobiologyZhejiang University School of MedicineHangzhou 310058ZhejiangChina

Neuropathic pain is a chronic pain caused by peripheral or central nervous system injury or diseases that affect the somatosensory nervous *** is usually associated with abnormal sensations called dysesthesia and exaggerated pain from normally innocuous stimuli(allodynia)or noxious stimuli(hyperalgesia),and also aversive emotional responses[1,2].Neuropathic pain can be very difficult to treat,as classical analgesics like opioids produce inadequate pain relief and may cause tolerance and hyperalgesia,and even addiction after long-term use[3].Thus,it is of critical importance to study the mechanisms of development,maintenance,and resolution of neuropathic *** study from ***’s research team at Zhejiang University reveals a critical regulatory mechanism for neuropathic pain[4].

关键词： sensation diseases opioid

One-Dimensional ZnO Nanostructures： Solution Growth and Functional Properties

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Nano Research 2011年第11期4卷 1013-1098页

作者： Sheng xu zhong Lin Wang School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia 30332-0245 USA

One-dimensional （1D） ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and future technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and the corresponding growth mechanisms, various nanostructures grown, their doping and alloying, and position-controlled growth on substrates. Finally, we will review their functional properties in catalysis, hydrophobic surface modification, sensing, and electronic, optical, optoelectronic, and energy harvesting devices.

关键词： ZnO one dimensional nanostructures solution growth electronic optical optoelectronic energy harvesting devices

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

SOME n-RECTANGLE NONCONFORMING ELEMENTS FOR FOURTH ORDER ELLIPTIC EQUATIONS

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Journal of Computational Mathematics 2007年第4期25卷 408-420页

作者： Ming Wang zhong-Ci Shi Jinchao xu LMAM School of Mathematical Sciences Peking University Beijing 100080 China LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China School of Mathematical Sciences Peking University Beijing 100080 China and Department of Mathematics Pennsylvania State University USA

In this paper, three n-rectangle nonconforming elements are proposed with n ≥ 3. They are the extensions of well-known Morley element, Adini element and Bogner-Fox-Schmit element in two spatial dimensions to any higher dimensions respectively. These elements are all proved to be convergent for a model biharmonic equation in n dimensions.

关键词： Nonconforming finite element Forth order elliptic equation Biharmonic.

Simulation Study of Passive Rod Diffusion in Active Bath:Nonmonotonic Length Dependence and Abnormal Translation-Rotation Coupling

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Chinese Journal of Chemical Physics 2021年第2期34卷 157-164,I0001页

作者： Rui-kai xu Hui-jun Jiang zhong-huai Hou Department of Chemical Physics&Hefei National Laboratory for Physical Sciences at the Microscale iChEMUniversity of Science and Technology of ChinaHefei 230026China

Diffusion of tracer particles in active bath has attracted extensive attention in recent *** far,most studies have considered isotropic spherical tracer particles,while the diffusion of anisotropic particles has rarely been *** we investigate the diffusion dynamics of a rigid rod tracer in a bath of active particles by using Langevin dynamics simulations in a two-dimensional *** attention is paid to how the translation(rotation)diffusion coefficient D_(T)(D_(R))change with the length of rod L and active strength *** all cases,we find that rod exhibits superdiffusion behavior in a short time scale and returns to normal diffusion in the long time *** D_(T) and D_(R) increase with Fa,but interestingly,a nonmonotonic dependence of D_(T)(D_(R))on the rod length has been *** have also studied the translation-rotation coupling of rod,and interestingly,a negative translation-rotation coupling is observed,indicating that rod diffuses more slowly in the parallel direction compared to that in the perpendicular direction,a counterintuitive phenomenon that would not exist in an equilibrium counterpart ***,this anomalous(diffusion)behavior is reentrant with the increase of Fa,suggesting two competitive roles played by the active feature of bath particles.

关键词： Active particle Translation-rotation coupling Anomalous diffusion