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WAVE MOTION OVER TWO SUBMERGED LAYERS OF HORIZONTAL THICK PLATES

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Journal of Hydrodynamics 2009年第4期21卷 453-462页

作者： LIU Yong LI Yu-cheng TENG Bin key laboratory of Ocean Engineering Shandong Province Ocean University of China Qingdao 266100 China key laboratory of Water and Sediment Science and Water Hazard Prevention Hunan Province Changsha 410076 China State key laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

This study investigates the hydrodynamic performance of a submerged two layer horizontal plate breakwater. The plate thickness is considered as non-zero in the study. In the context of linear potential theory, an analytical solution for interaction of water waves with the plates is obtained using the matched eigenfunction expansion method. The solution consists of a symmetric part and an antisymmetric part. Its validity is confirmed by comparing the numerical results of reflection and transmission coefficients for limiting cases with previous predictions. Numerical examples are given to examine the major factors that affect the reflection and transmission coefficients of the plates. Some useful results are presented for engineering design.

关键词： submerged breakwater horizontal thick plate reflection coefficient transmission coefficient

Anisotropic characteristics of electrical responses of fractured reservoir with multiple sets of fractures

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Petroleum Science 2009年第2期6卷 127-138页

作者： Shen Jinsong Su Benyu Guo Naichuan Department of Geophysics School of Resource and Information Technology China University of Petroleum Beijing 102249 China key laboratory of CNPC Geophysical Exploration China University of Petroleum Beijing 102249 China State key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China

In fractured reservoirs, the fractures not but also form the main flow channels which connect productivity of reservoirs. However, because of the only provide the storage space for hydrocarbons, the pores of the matrix, so fractures dominate the heterogeneity and randomness of the distribution of fractures, exploration and evaluation of fractured reservoirs is still one of the most difficult problems in the oil industry. In recent years, seismic anisotropy has been applied to the assessment of fractured formations, whereas electrical anisotropy which is more intense in fractured formations than seismic anisotropy has not been studied or used so extensively. In this study, fractured reservoir models which considered multiple sets of fractures with smooth and partly closed, rough surfaces were established based on the fractures and pore network, and the vertical and horizontal electrical resistivities were derived as a function of the matrix and fracture porosities according to Ohm＇s law. By using the anisotropic resistivity equations, variations of the electrical anisotropy of three types of fractured models under the conditions of free pressure and confining pressure were analyzed through the variations of the exerted pressure, matrix porosity, fracture aperture and formation water resistivity. The differences of the vertical and horizontal resistivities and the anisotropy between the connected and non-connected fractures were also analyzed. It is known from the simulated results that an increase of the confining pressure causes a decrease of electrical anisotropy because of the elasticity of the closed fractures and the decrease of the fracture aperture. For a fixed fracture porosity, the higher the matrix porosity, the weaker the electrical anisotropy in the rock formation.

关键词： Fractured reservoir partly closed fracture electrical anisotropy fracture roughness

A first-principles study of dihydroazulene as a possible optical molecular switch

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Science china(Physics,Mechanics & Astronomy) 2011年第3期Mechanics & Astronomy) .卷 437-441页

作者： XIA CaiJuan1, LIU DeSheng2,3 & LIU HanChen1 1 School of Science, Xi’an Polytechnic University, Xi’an 710048, china 2 School of Physics, State key laboratory of Crystal Materials, Shandong University, Jinan 250100, china 3 Department of Physics, Jining University, Qufu 273155, china 1. School of Science Xi’an Polytechnic University Xi’an 710048 China2. School of Physics State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China3. Department of Physics Jining University Qufu 273155 China

By applying nonequilibrium Green's function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of the dihydroazulene optical molecular switch. Three kinds of adsorption sites including the hollow, bridge and top sites are studied. The two forms of this molecule, namely the open form and the closed form, can reversibly switch from each other upon photoexcitation. Their transmission spectra are remarkably distinctive. Theoretical results show that the current of the closed form is always significantly larger than that of the open form for all three adsorption sites, which promises this system as possibly one of the good candidates for optical switches due to its unique advantage, and which may have some potential applications in the future molecular circuit.

关键词： molecular switch nonequilibrium Green’s function electronic transport density functional theory

Computational RNomics:Structure identification and functional prediction of non-coding RNAs in silico

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Science china(Life Sciences) 2010年第5期53卷 548-562页

作者： ZHENG LingLing & QU LiangHu key laboratory of Gene Engineering of the Ministry of Education,State key laboratory for Biocontrol,Sun Yat-sen University,Guangzhou 510275,china 1. key laboratory of Gene Engineering of the Ministry of Education State Key Laboratory for Biocontrol Sun Yat-sen University Guangzhou 510275 China

The eukaryotic genome contains varying numbers of non-coding RNA(ncRNA) genes."Computational RNomics" takes a multidisciplinary approach,like information science,to resolve the structure and function of ***,we review the main issues in "Computational RNomics" of data storage and management,ncRNA gene identification and characterization,ncRNA target identification and functional prediction,and we summarize the main methods and current content of "computational RNomics".

关键词： non-coding RNA eukaryote computational RNomics

Mechanical decision for a class of integral inequalities

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Science china(Information Sciences) 2010年第9期53卷 1800-1815页

作者： YANG Lu1,3,YU WenSheng1,2* & YUAN RuYi2 1Shanghai key laboratory of Trustworthy Computing,Software Engineering Institute,East china Normal University,Shanghai 200062,china 2The key laboratory of Complex Systems and Intelligence Science,Institute of Automation,Chinese Academy of Sciences,Beijing 100190,china 3laboratory for Automated Reasoning and Programming,Chengdu Institute of Computer Applications,Chinese Academy of Sciences,Chengdu 610041,china 1. Shanghai key laboratory of Trustworthy Computing Software Engineering Institute East China Normal University Shanghai 200062 China3. Laboratory for Automated Reasoning and Programming Chengdu Institute of Computer Applications Chinese Academy of Sciences Chengdu 610041 China2. The Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing 100190 China

A class of integral inequalities is transformed into homogeneous symmetric polynomial inequalities beyond Tarski model,where the number of elements of the polynomial,say n,is also a variable and the coefficients are functions of *** is closely associated with some open problems formulated recently by Yang et *** Timofte's dimension-decreasing method for symmetric polynomial inequalities,combined with the inequality-proving package BOTTEMA and a program of implementing the method known as successive difference substitution,we provide a procedure for deciding the nonnegativity of the corresponding polynomial inequality such that the original integral inequality is mechanically decidable;otherwise,a counterexample will be *** effectiveness of the algorithm is illustrated by some more examples.

关键词： integral inequality symmetric polynomial inequality Timofte’s dimension-decreasing method successive difference substitution mechanical decision inequality-proving package BOTTEMA

ADAPTIVE VARIABLE STRUCTURE CONTROLLERS AND APPLICATION TO ENGINE IDLE SPEED CONTROL SIMULATION

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Chinese Journal of Mechanical Engineering 2003年第2期16卷 171-174页

作者： Hui Qing Quyang MinggaoState key laboratory of AutomotiveSafety and Energy,Tsinghua University,Beijing 100084, china State key laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China

A neural-network-based adaptive variable structure control methodology isproposed for the tracking problem of nonlinear discrete-time input-output systems. The unknowndynamics of the system are approximated via radial basis function neural networks. The control lawis based on sliding modes and simple to implement. The discrete-time adaptive law for tuning theweight of neural networks is presented using the adaptive filtering algorithm with residueupper-bound compensation. The application of the proposed controller to engine idle speed controldesign is discussed. The results indicate the validation and effectiveness of this approach.

关键词： variable structure control adaptive control neural networks nonlineardiscrete-time systems idle speed control

New insight into the role of miRNAs in leukemia

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Science china(Life Sciences) 2009年第3期52卷 224-231页

作者： ZHANG Hua & CHEN YueQin key laboratory of Genetic Engineering of the Ministry of Education,State key laboratory of Biocontrol,Sun Yan-Sen University,Guangzhou 510275,china 1. key laboratory of Genetic Engineering of the Ministry of Education State Key Laboratory of Biocontrol Sun Yan-Sen University Guangzhou 510275 China

Recent studies have shown that microRNAs(miRNAs) play an important role in cell differentiation,growth,and death,including the functional study of miRNAs in *** date,miRNA expression profiles in many types of cancers have been identified and miRNA expression signatures associated with types and cytogenetics of leukemia have also been *** evidence has shown that miRNAs could function as either tumor suppressors or oncogenes in cancers such as leukemia,while other miRNAs might be benefitcial for diagnosis and prognosis,predicted to be newly developed *** this review,we summarize the recent progress about miRNAs in leukemia and present a miRNA-mediated network involved in differentiation,proliferation and apoptosis predicted to be the roles of miRNAs in the pathogenesis of leukemia.

关键词： miRNA leukemia regulation network clinical implication

An integrated turbocharger design approach to improve engine performance

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Science china(Technological Sciences) 2010年第1期53卷 69-74页

作者： ZHANG YangJun1,CHEN Tao1,ZHUGE WeiLin1,ZHANG ShuYong2 & XU JianZhong3 1 State key laboratory of Automotive Safety and Energy,Tsinghua University,Beijing 100084,china 2 National key laboratory of Diesel Engine Turbocharging Technology,P.O.B.22,Datong 037036,china 3 Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,china 1. State key laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China2. National Key Laboratory of Diesel Engine Turbocharging Technology P.O.B. 22 Datong 037036 China3. Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China

Turbocharging technology is today considered as a promising way for internal combustion engine energy saving and CO2 *** design is a major challenge for turbocharged engine performance *** turbocharger designer must draw upon the information of engine operation conditions,and an appropriate link between the engine requirements and design features must be carefully developed to generate the most suitable design *** objective of this research is to develop a turbocharger design approach for better turbocharger matching to an internal combustion *** development of the approach is based on the concept of turbocharger design and interaction links between engine cycle requirements and design parameter values.A turbocharger through flow model is then used to generate the design *** integrated method has been applied with success to a gasoline engine turbocharger assembly.

关键词： turbocharger design internal combustion engine integrated method through flow model

DYNAMICAL BALANCE STUDY OF RING REDUCER

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Chinese Journal of Mechanical Engineering 2003年第1期16卷 87-90页

作者： Zhu Caichao Qin DatongState key laboratory ofMechanical Transmission,Chongqing University,Chongqing 400044, china State key laboratory of Mechanical Transmission Chongqing University Chongqing 400044 China

The basic structure of epicyclical gear transmission with inner teeth ofsingle-ring, double-ring, three-ring and four-ring reducer are analyzed. The force analysis model ofring reducer is built. Following this, it is concluded that the present ring reducer~ have theproblem that the inertia force or the inertia moment is lopsided. On the base of analysis andcalculation the balanced ring reducer which can realize the balance of inertia force and inertiamoment is brought forward, and so is its concrete realizing step. The specimen of the balanced ringreducer is designed and manufactured; the experiment is carried out on the gear transmission testbench. Compared with other ring reducer of the same power, the balanced ring reducer has manyadvantages, such as low vibration noise, low cost and less production difficulty and less heat. Itis the substitute of other ring reducer of the same kind. Therefore, it has important theoreticsignificance and highly practical engineering value.

关键词： Dynamical balance Reducer Vibration Noise