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Manipulating a micro-cantilever between its optomechanical bistable states in a lever-based Fabry-Pérot cavity

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Science China(Physics,Mechanics & Astronomy) 2015年第5期58卷 41-45页

作者： fu Hao DING JiangFang LI Yong cao GengYu State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of Sciences University of Chinese Academy of Sciences Beijing Computational Science Research Center

In this paper, we demonstrate experimentally switching a cantilever between its optomechanical bistable states in a low finesse optical cavity. Our experiment shows that the deformation of cantilever can be manipulated by tuning the cavity resonance. When the laser power increases across the threshold value of 110 ?W, optomechanical bistability is induced by strong static photothermal backaction at room temperature. Numerical calculation revealed that the bistable effect originates from the multi-well potential created via the optomechanical interaction. Switching of the cantilever between the bistable states was achieved by tuning the cavity to the corresponding boundaries of the bistable region, where the barrier between the bistable states vanishes.

关键词： optomechanical bistability static deformation control optomechanical switch photothermal backaction micro-cantilever

Discrete Numerical Study on Type II Fracture of Partially Detached Concrete Panels in Cold Region

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Structural Durability & Health Monitoring 2025年第1期19卷 167-191页

作者： Huayi Zhang Maobin Song Lei Shen Nizar Faisal Alkayem Maosen cao College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210024China Haihe River Huaihe River and Xiaoqinghe River Basin Water Conservancy Management and Service Center of Shandong ProvinceJinan250100China College of Mechanics and Engineering Science Hohai UniversityNanjing211100China

When the upper chord beam of the beam-string structure(BSS)is made of concrete-ﬁlled steel tube(CFST),its overall stiffness will change greatly with the construction of concrete placement,which will have an impact on the design of the tensioning plans and selection of control measures for the *** order to accurately obtain the bending stiffness of CFST beam and clarify its impact on the mechanical properties of composite BSS during con-struction,the inﬂuence of some factors such as height-width ratio,wall thickness of steel tube,elasticity modulus of concrete,and friction coefﬁcient on the bending stiffness are analyzed parametrically by the numerical simula-tion technology based on an actual *** calculation formula of the equivalent bending stiffness of CFST is also established through mathematical statistical ***,the equivalent bending stiffness is introduced into the construction and use stages of the composite BSS,respectively,and the mechanical properties such as prestress-tensioning control value,structural deformation,and internal force of key members are comparatively analyzed when adopting two different construction ***,the optimal construction plan of concrete placementﬁrst and then prestress-tensioning is proposed.

关键词： Beam-string structure(BSS) concrete-ﬁlled steel tube(CFST) bending stiffness timing of concrete placement prestress-tensioning

MHD and kinetic analysis of flow bursts in the Earth's plasma sheet

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Science China(Technological Sciences) 2014年第1期57卷 55-66页

作者： MA YuDuan cao JinBin fu HuiShan REME H. DANDOURAS I. yang JunYing WANG ZhiQiang TAO Dan yang Jian School of Astronautics Beihang University SOA Key Laboratory for Polar Science Polar Research Institute of China University of Toulouse UPS-OMP IRAP Toulouse 31028 France The French National Centre for Scientific Research The Research Institute in Astrophysics and Planetology BP 44346F-31028 Toulouse cedex 4 France Nanjing University of Aeronautics and Astronautics

In an attempt to study the flow bursts in the Earth＇s plasma sheet we select an event that took place on August 7, 2004 in the expansion phase of a substorm, using data from the geomagnetic index, solar wind data, plasma and magnetic field observa- tions from C1 Cluster satellite （the Cluster mission has 4 satellites） and from Double Star TC-1 satellite. In MHD approach, TC-1 firstly observed the tailward flow, then the earthward, and finally the flow altemated in two directions. C1 firstly ob- served the earthward plasma flow, and then the tailward plasma flow. Before flow bursts are observed by TC-1 and C1, there are disturbances in local entropy with their tailward local entropy larger than those of the earthward. The kinetic features of the plasma flow observed by C1 are similar to those in MHD. However, kinetic characteristics of the plasma flow observed by TC-1 are far more than the description in MHD. The inadequacy mainly exists in two cases：（i） the firstly enhanced tailward flows given in MHD are found without significant increase of the energetic tailward flux; （ii） the almost stagnant flow in MHD is composed of the enhanced energetic ion flux in both earthward and tailward directions. The earthward flow burst observed by TC-1 might be multiple overshoots and rebounds. The earthward flow burst observed by C1 might be simply rebounded in the near-Earth. The pulsation observed by C1 is earlier than that observed by TC-1 with the former intensity less than that of the latter. After the energetic ion flux in the tailward direction is significantly enhanced, the power spectrum intensity of the ULF wave commences to increase obviously, which may suggest that the stream instability is closely correlated with ULF pulsations.

关键词： MHD kinetic flux entropy

MODIFIED PARALLEL ROSENBROCK METHODS FOR STIFF DIFFERENTIAL EQUATIONS

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Journal of Computational Mathematics 2002年第1期20卷 23-34页

作者： Xue-nian cao Shou-fu Li De-gui Liu Institute for Computational and Applied Mathematics Xiangtan UniversityXiangtan 411105China Beijing Institute of Computer Application and Simulation Technology Beijing 100854China

Presents a class of modified parallel Rosenbrock methods (MPROW) which possesses more free parameters to improve further the various properties of the methods and will be similarly written as MPROW. Information on par... 详细信息

关键词： numerical analysis stiff ordinary differential equations Rosenbrock methods parallel algorithms

Cryo-EM Studies of Virus-Antibody Immune Complexes

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Virologica Sinica 2020年第1期35卷 1-13页

作者： Na Li Zhiqiang Li Yan fu Sheng cao CAS Key Laboratory of Special Pathogens and Biosafety Wuhan Institute of VirologyWuhan 430071China Center for Biosafety Mega-Science Chinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China

Antibodies play critical roles in neutralizing viral infections and are increasingly used as therapeutic drugs and diagnostic tools. Structural studies on virus-antibody immune complexes are important for better understanding the molecular mechanisms of antibody-mediated neutralization and also provide valuable information for structure-based vaccine ***-electron microscopy(cryo-EM) has recently matured as a powerful structural technique for studying bio-macromolecular complexes. When combined with X-ray crystallography, cryo-EM provides a routine approach for structurally characterizing the immune complexes formed between icosahedral viruses and their antibodies. In this review, recent advances in the structural understanding of virus-antibody interactions are outlined for whole virions with icosahedral T = pseudo 3(picornaviruses) and T = 3(flaviviruses) architectures, focusing on the dynamic nature of viral shells in different functional states. Glycoprotein complexes from pleomorphic enveloped viruses are also discussed as immune complex antigens. Improving our understanding of viral epitope structures using virus-based platforms would provide a fundamental road map for future vaccine development.

关键词： Cryo-electron microscopy(Cryo-EM) Icosahedral Antigen Virion Immune complex

Weighted Composition Operators between Bergman Spaces with Exponential Weights

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Acta Mathematica Sinica,English Series 2022年第12期38卷 2231-2252页

作者： Guang fu cao Li HE Yi Yuan ZHANG School of Mathematics and Information Science Guangzhou UniversityGuangzhou 510006P.R.China

In this paper,we study some properties of weighted composition operators on a class of weighted Bergman spaces Ap with O 详细信息

In this paper,we study some properties of weighted composition operators on a class of weighted Bergman spaces Ap with Ofunction and the generalized Berezin transform with 0

关键词： Weighted composition operator boundedness compactness Schatten class Bergman spaces

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A Configurable Circuit for Cross-Correlation in Real-Time Image Matching

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Journal of Computer Science & Technology 2017年第6期32卷 1305-1318页

作者： Quan Zhou Liang yang Hui cao Department of Integrated Circuit Design Xi'an Microelectronics Technology Institute Xi'an 710065 China

Cross-correlation （CC） is the most time-consuming in the implementation of image matching algorithms based on the correlation method. Therefore, how to calculate CC fast is crucial to real-time image matching. This work reveals that the single cascading multiply-accumulate （CAMAC） and concurrent multiply-accumulate （COMAC） architectures which have been widely used in the past, actually, do not necessarily bring about a satisfactory time performance for CC. To obtain better time performance and higher resource efficiency, this paper proposes a configurable circuit involving the advantages of CAMAC and COMAC for a large amount of multiply-accumulate （MAC） operations of CC in exhaustive search. The proposed circuit works in an array manner and can better adapt to changing size image matching in real-time processing. Experimental results demonstrate that this novel circuit which involves the two structures can complete vast MAC calculations at a very high speed. Compared with existing related work, it improves the computation density further and is more flexible to use.

关键词： cross-correlation image matching multiply-accumulate speed-up ratio template matching

Flow resistance and its prediction methods in compound channels

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Acta Mechanica Sinica 2007年第1期23卷 23-31页

作者： Kejun yang Shuyou cao Xingnian Liu State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065 China

A series of experiments was carried out in a large symmetric compound channel composed of a rough main channel and rough floodplains to investigate the resistance characteristics of inbank and overbank flows. The effective Manning, Darcy-Weisbach, Chezy coefficients and the relative Nikuradse roughness height were analyzed. Many different representative methods for predicting the composite roughness were systematically summarized. Besides the measured data, a vast number of laboratory data and field data for compound channels were collected and used to check the validity of these methods for different subsection divisions including the vertical, horizontal, diagonal and bisectional divisions. The computation showed that these methods resulted in big errors in assessing the composite roughness in compound channels, and the reasons were analyzed in detail. The error magnitude is related to the subsection divisions.

关键词： Flow resistance Compound channels Bed roughness Inbank and overbank flows Subsection division

Study on resistance coefficient in compound channels

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Acta Mechanica Sinica 2005年第4期21卷 353-361页

作者： Kejun yang Shuyou cao Xingnian Liu State Key Laboratory of Hydraulics on High Speed Flows Sichuan University Chengdu 610065 China

This paper presents a further study of the Manning and Darcy-Weisbach resistance coefficients, as they play a significant role in assessing the cross-sectional mean velocity, conveyance capacity and determining the lateral distribution of depth mean velocity and local boundary shear stress in compound channels. The relationships between the local, zonal and overall resistance coefficients, and a wide range of geometries and different roughness between the main channel and the flood plain are established by analyzing a vast amount of experimental data from a British Science and Engineering Research Council Flood Channel Facility （SERC-FCF）. And the experimental results also show that the overall Darcy-Weisbach resistance coefficient for a compound channel is the function of Reynolds number, but the function relationship is different from that for a single channel. By comparing and analyzing the conventional methods with the experimental data to predict composite roughness in compound channels, it is found that these methods are not suitable for compound channels. Moreover, the reason why the conventional methods cannot assess correctly the conveyance capacity of compound channels is also analyzed in this paper.

关键词： Resistance coefficient ,Compound channels,Geometries Roughness Reynolds number Computational methods for composite roughness