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Study on flow behavior and structure over chined fuselage at high angle of attack

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Science China(Technological Sciences) 2010年第8期53卷 2057-2067页

作者： TIAN Wei,DENG XueYing ,WANG YanKui,FAN GuoLei&DONG Chao ministry of education {2. laboratory of fluid mechanics,beijing university of Aeronautics and Astronautics,beijing 100191,China 1. ministry of education {2. laboratory of fluid mechanics Beijing University of Aeronautics and Astronautics Beijing 100191 China

A study of leeward vortex structure over chined fuselage and the effects of micro tip p.r.urbation on its vortex flow have been carried out in wind tunnel exp.r.ments at reynolds numbers from 1.2.×105 to 5.04×105 with pIV and pressure measurement ***,the exp.r.ment results have proved that micro tip p.r.urbation has no effects on the vortex flow and its aerodynamic characteristics over chined fuselage at high angle of attack,in which there are not any non-deterministic flow ***,the evolution of leeward vortex structure over chined fuselage along the axis of model can be divided into four flow regimes:linear conical developed regime,decay regime of leeward vortex intensity,asymmetric leeward vortex break down regime and completely break down *** a correlation between leeward vortex structure and sectional aerodynamic force was also revealed in the present ***,the exp.r.ment results show the behavior of leeward vortex core trajectories and zonal characteristics of leeward vortex structure with angles of ***,the exp.r.ment results of reynolds number effect on the leeward vortex flow have further confirmed research conclusions from previous studies:the flows over chined fuselage at high angles of attack are insensitive to variation of reynolds number,and there is a little effect on the secondary boundary layer sep.r.tion and the suction peak induced by leeward vortex.

关键词： high angle of attack aerodynamics chined fuselage tip p.r.urbation leeward vortex structure zonal characteristics

The C-topology on lattice-ordered groups

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Science China Mathematics 2009年第11期52卷 2397-2403页

作者： YANG YiChuan Dep.r.ment of Mathematics,key {2. of ministry of education for Information Mathematics and Behavior,beihang university,beijing,100191 China 1. Dep.r.ment of Mathematics Key Laboratory of Ministry of Education for Information Mathematics and Behavior Beihang University 100191 Beijing China

Let A be a lattice-ordered group. Gusi? showed that A can be equipped with a C-topology which makes A into a topological group. We give a generalization of Gusi?’s theorem, and reveal the very nature of a “C-group” of Gusi? in this pap.r. Moreover, we show that the C-topological groups are topological lattice-ordered groups, and prove that every archimedean lattice-ordered vector space is a T 2.topological lattice-ordered vector space under the C-topology. An easy example shows that a C-group need not be T 2. A further example demonstrates that a T 2.topological archimedean lattice-ordered group need not be C-archimedean, either.

关键词： C-topology lattice-ordered group archimedean lattice-ordered group Hausdorff topology vector space 06F30 2.A99

Simulation of three-dimensional nonideal MHD flow at high magnetic reynolds number

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中国科学：技术科学英文版 2010年第1期53卷 206-212页

作者： LU HaoYu1 & Lee ChunHian2.1 School of Astronautics,beihang university,beijing 100191,China 2.National {2. for Computational fluid Dynamics,beihang university,beijing 100191,China 1. School of Astronautics Beihang University Beijing 100191 China2. National Laboratory for Computational Fluid Dynamics Beihang University Beijing 100191 China

A conservative TVD scheme is adopted to solve the equations governing the three-dimensional flow of a nonideal compressible conducting fluid in a magnetic *** eight-wave equations for magnetohydrodynamics(MHD) are proved to be a non-strict hyp.r.olic system,therefore it is difficult to develop its *** developed a new set of equations which cannot be numerically simulated by conservative TVD scheme directly due to its non-conservative form.A conservative TVD scheme augmented with a new set of eigenvectors is proposed in the *** validate this scheme,1-D MHD shock tube,unsteady MHD rayleigh problem and steady MHD Hartmann problem for different flow conditions are *** simulated results are in good agreement with the existing analytical *** this scheme can be used to effectively simulate high-conductivity fluids such as cosmic MHD problem and hyp.r.onic MHD flow over a blunt body,etc.

关键词： magnetohydrodynamics(MHD) numerical simulation TVD MHD rayleigh flow MHD Hartmann flow

Optimized statistical analysis of software trustworthiness attributes

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Science China(Information Sciences) 2012年第11期55卷 2508-2520页

作者： ZHANG Xiao1,LI Wei2.ZHENG ZhiMing1,2.& GUO BingHui1 1key laboratory of Mathematics,Informatics and Behavioral Semantics,{2. of education,beihang university,beijing 100191,China 2.tate key laboratory of Software Development Environment,beihang university,beijing 100191,China 1. key laboratory of Mathematics Informatics and Behavioral Semantics Ministry of Education Beihang University Beijing 100191 China2. State Key Laboratory of Software Development Environment Beihang University Beijing 100191 China

Software trustworthiness has become one of the key restrictions for software service quality and the development of the software ***,trustworthiness attributes interlace structured and dynamical coupling relations,which causes great barriers for trustworthiness measurements of large-scale *** to the dynamical evolutionary characteristics of software trustworthiness attributes,this pap.r.proposes a new ap.r.ach for optimizing the trustworthiness measurement in terms the kernel trustworthiness attributes,and improves a downsize-optimized statistical analysis method for software trustworthiness attributes based on their nonlinear *** improved method considerably simplifies the trustworthiness assessment of largescale *** theoretical analysis and numerical simulations,the feasibility of this method is verified using two typical examples that illustrate the realization of the trustworthiness measurement.

关键词： software trustworthiness kernel attributes optimization statistical analysis

petrogenesis of Songshugou dunite body in the Qinling orogenic belt, Central China: Constraints from geochemistry and melt inclusions

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Science China Earth Sciences 2005年第8期48卷 1146-1157页

作者： SU Li1,2. SONG Shuguang3 & ZHOU Dingwu1 1. key laboratory of Continental Dynamics of the {2. of education, Dep.r.ment of Geology, Northwestern university, Xi’an 710069, China 2. The Geological Lab Center, China university of Geosciences (beijing), beijing 100083, China 3. key laboratory of Orogenic Belts of the {2. of education, Dep.r.ment of Geology, peking university, beijing 100871, China 1. key laboratory of Continental Dynamics of the {2. of education Department of Geology Northwestern University 710069 Xi’an China 2. The Geological Lab Center China University of Geosciences 100083 (Beijing)Beijing China 3. key laboratory of Orogenic Belts of the {2. of education Department of Geology Peking University 100871 Beijing China

The Songshugou dunite body, which occupies an area of about 2. km2. is the largest ultramafic massif in the eastern Qinling orogenic belt, Central China. The major compo-nent of this body is dunitic rocks including mylonitic dunite and coarse-grained dunite; they oc-cupy about 95 vol% of the total body. petrography, mineral composition, major and trace ele-ments and primitive melt inclusions have been investigated in this pap.r. all revealed that this dunite body is the product of melt-rock interaction by p.r.us p.r.olation flow. In comp.r.son with dunite sills or veins in harzburgite from the basal p.r. of Oman ophiolite, this dunite body is characterized by lower contents of Al2.3, CaO and HrEE but higher content of highly incom-patible elements and Zr and Hf. The LrEE enriched patterns and primitive mantle normalized spidergrams of trace elements are also different from the Oman dunite. Combining with melt in-clusions observed in olivines, we conclude that this dunite body is the product of large- scale p.r.us p.r.olation flow of high-MgO melts within depleted mantle p.r.dotites. The high-MgO magma, in essence, was most probably produced at the hot head of an upwelling mantle plume. The occurrence of the Songshugou dunite body is closely associated with the activity of mantle sup.r.plume in Neo-proterozoic era in the Yangtze Craton.

关键词： Songshugou dunite body, geochemistry, melt inclusion, mantle plume, Qinling orogenic belt.

Analysis of residual stress distribution along interface asp.r.ty of thermal barrier coating system on macro curved surface

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progress in Natural Science:Materials International 2011年第3期21卷 262-267页

作者： Ming SONG,Yue MA,Sheng-kai GONG key laboratory of Aerospace Materials and {2.ormance(ministry of education), School of Materials Science and Engineering,beihang university,beijing 100191,China key laboratory of Aerospace Materials and {2.ormance (ministry of education) School of Materials Science and Engineering Beihang University Beijing 100191 China

Based on the study of the radial residual stress distribution on the macro curved interfaces of thermal barrier coating system(TBCs) for the hollow curved substrate structures,the hollow four-concentric-circle model was *** the concentric-circle model with a fine scaled sinusoidal interface was proposed to describe the stresses distribution on the rough interface of TBCs with macro curved *** influences of the geometric and thermophysical p.r.meters were discussed by the developed *** results showed that the radial stress on the rough interface can be sep.r.ted into two sections:the overall level stress from macro surface curvature and the local stress from local asp.r.ty of the *** overall level stress was determined by the thicknesses and the thermophysical p.r.meters of each *** has been found that the ratio of local stress and overall level stress was influenced by the interface asp.r.ty,the ratio of elastic modulus and the ratio of thermal expansion coefficients of the layers beside the rough ***,the convex macro curvature of the substrate can induce tensile stress onto the *** at the sharp corners of the substrate,the small curvature radius can cause high stress which should be taken more care about the occurrence of spalling cracking at interface

关键词： barrier coating system(TBC) residual stress interface asp.r.ty thermal grown oxide(TGO) concentric-circle model

Scanning near-field acoustic microscope and its application

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Science China(Technological Sciences) 2011年第1期54卷 126-130页

作者： XU ping,CAI Wei & WANG rongMing key laboratory of Micro-nano Measurement-Manipulation and physics ({2. of education) Dep.r.ment of physics,beihang university,beijing 100191,China 1. key laboratory of Micro-nano Measurement-Manipulation and physics ({2. of education) Dep.r.ment of physics Beihang University Beijing 100191 China

Scanning near-field acoustic microscope （SNAM） combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or detected in near-field area whether ultrasonic transducer acts as generator or detector. The resolution of SNAM can reach to nanometer scale. First, two typical SNAMs, scanning electron acoustic Inicroscope and scanning probe acoustic microscope, will be introduced in this pap.r. The working principle of our homemade SNAM based on a commercial scanning probe microscope will be rep.r.ed, together with some recent results from this homemade SNAM.

关键词： scanning near-field acoustic microscope ultrasonic detection technology scanning probe microscopy

Complexity of synthesis of composite service with correctness guarantee

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Science China(Information Sciences) 2012年第3期55卷 638-649页

作者： DENG Ting1,2., HUAI Jinpeng1,3 & WO TianYu1,3 1State key laboratory of Software Development Environment, {2. beijing 100191, China 2.chool of Mathematics and System Science, {2., beijing 100191, China 3School of Computer Science and Engineering, {2., beijing 100191, China 1. State key laboratory of Software Development Environment Beihang University Beijing 100191 China2. School of Mathematics and System Science Beihang University Beijing 100191 China3. School of Computer Science and Engineering Beihang University Beijing 100191 China

How to compose existing web services automatically and to guarantee the correctness of the design (e.g. temp.r.l constraints specified by temp.r.l logic LTL, CTL or CTL*) is an imp.r.ant and challenging problem in web services. Most existing ap.r.aches use the process in conventional software development of design, verification, analysis and correction to guarantee the correctness of composite services, which makes the composition process both complex and time-consuming. In this pap.r. we focus on the synthesis problem of composite service; that is, for a given set of services and correctness constraint specified by CTL or CTL* formula, a composite service is automatically constructed which guarantees that the correctness is ensured. We prove that the synthesis problem for CTL and CTL* are complete for EXpTIME and 2.XpTIME, respectively. Moreover, for the case of synthesis failure, we discuss the problem of how to disable outputs of environment (i.e. users or services) reasonably to make synthesis successful, which are also proved complete for EXpTIME and 2.XpTIME for CTL and CTL*, respectively.

关键词： business protocol composite service synthesis environment branching temp.r.l logic

Flow structures in flat plate boundary layer induced by pulsed plasma actuator

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Science China(Technological Sciences) 2010年第4期53卷 2772-2782页

作者： ZHANG panFeng1,2. LIU AiBing1 & WANG JinJun1,2.1Institute of fluid mechanics, {2. university of Aeronautics and Astronautics, beijing 100191, China 2.5} laboratory of fluid mechanics, ministry of education, beijing 100191, China 1. Institute of fluid mechanics Beijing University of Aeronautics and Astronautics Beijing 100191 China2. Key Laboratory of Fluid Mechanics Ministry of Education Beijing 100191 China

The flow field in the flat plate boundary layer induced by the pulsed plasma actuator was simulated by solving the Navier-Stokes equations with a phenomenological DBD plasma model. The effects of actuation strength,wave form and frequency on the flow structures induced by the unsteady pulsed plasma actuator were investigated. The results indicated that a series of vortex pairs were formed in the boundary layer,and decayed in downstream convection following the exponential law. The strength of vortex pair was dominated by the effective plasma actuation strength,and the vortex streamwise spacing depended on the actuation frequency. If the duty cycle is not so large that interaction of adjacent vortex pairs can be negligible,then the actuation wave form has little influence on the vortex pair induced by the unsteady plasma actuator.

关键词： plasma actuator unsteady actuation boundary layer numerical simulation

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