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TRANSIENT EFFECT OF A BOGER FLUID FLOWING AROUND A CONFINED CYLINDER

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chinese Journal of Polymer Science 2001年第4期19卷 377-384页

作者： Xian-feng Li Huai-tian Bu De-lu Zhao State Key Laboratory of Polymer Physics and chemistry Center for Molecular Science,institute of chemistry, chinese academy of sciences, beijing 100080, china chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China

This paper is concerned with the numerical simulation of the transient effect of an inertialess Boger flow past a confined circular cylinder and the comparison of predictions with particle image velocimetry (PIV) measurements given by shiang et al.. Dynamic simulation based on the Oldroyd-B constitutive model was carried out using a Lagrangian-Eulerian algorithm. The evolution of velocity field was obtained for the flow at two Deborah (De) numbers, i.e. De = 1.2 and 3.0. At low De, the flow reached steady state rapidly, and showed a symmetric flow regime. However, at high De, the time required to reach steady flow behind the cylinder increased significantly, and the distribution of the velocity field appears to be asymmetric with respect to the stagnation line. Fairly good agreement between the numerical results and the experimental observations is reported. It can be concluded that both the experimental measurements and the present simulations indicate that the elasticity of the polymeric flow strongly affect the flow regime of viscoelastic flow around a confined cylinder.

关键词： transient effect flow around a cylinder Lagrangian-Eulerian algorithm Oldroyd-B model

One-dimensional unsteady general solution for Wang bioheat transfer equation with heat source proportional to temperature

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Progress in Natural Science:Materials International 2006年第7期16卷 766-768页

作者： GOU Chenhua and CAI Ruixian ( institute of Engineering Thermophysics, chinese academy of sciences, beijing 100080, china Graduate School, chinese academy of sciences, beijing 100080, china) [a]institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China [b]Graduate School Chinese Academy of Sciences Beijing China

An analytical general solution is derived for the non-Fourier Wang bioheat transfer model with special internal heat production. It is valuable for finding the special solutions with specified conditions and for expanding the understanding of the non-Fourier heat conduction phenomena in living tissues, for example, the controversial temperature fluctuation effects. This analytical solution can also be used as the benchmark solution to check the numerical calculations and to develop various numerical computational approaches. Because there is an arbitrary function in the expression of internal heat production, this solution can actually be applied to many types of internal heat production distributions.

关键词： bioheat transfer model non-fourier effect analytical solution

Modeling and verifying Web services driven by requirements:An ontology-based approach

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Science in china(Series F) 2006年第6期49卷 792-820页

作者： HOU Lishan1,3,JIN ZHi1,2 & WU Budan1,4 1. academy of Mathematics and Systems Science, chinese academy of sciences, beijing 100080, china 2. institute of Computing Technology, chinese academy of sciences, beijing 100080, china 3. institute of Software, chinese academy of sciences, beijing 100080, china 4. Graduate University of chinese academy of sciences, beijing 100049, china 1. academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China 3. institute of Software Chinese Academy of Sciences Beijing 100080 China 2. institute of Computing Technology Chinese Academy of Sciences Bejing 100080 China 4. Graduate University of chinese academy of sciences Beijing 100049 China

Automatic discovery and composition of Web services is an important research area in Web service technology, in which the specification of Web services is a key issue. This paper presents a Web service capability description framework based on the environment ontology. This framework depicts Web services capability in two aspects： the operable environment and the environment changes resulting from behaviors of the Web service. On the basis of the framework, a requirement-driven Web service composition model has been constructed. This paper brings forward the formalization of Web service interactions with π calculus. And an automatic mechanism converting conceptual capability description to the formal process expression has been built. This kind of formal specification assists in verifying whether the composite Web service model matches the requirement.

关键词： Web service environment ontology automatic composition π calculus formal verification.

LARGE-EDDY SIMULATION OF THREE-DIMENSIONAL TURBULENT FLOW AROUND A CIRCULAR PIER

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Journal of Hydrodynamics 2006年第6期18卷 765-772页

作者： Huhe Aode institute of Mechanics Chinese Academy of SciencesBeijing 100080China

ABSTRACT： In this article, the turbulent flow field and the scouring mechanism around a circular pier were numerically investigated using the Large Eddy Simulation （LES） method for three scouring holes. The effects of the bottom topographies on the flow structure were studied in detail. The results show that at the downstream of the pier, as the scouring depth increases, the bed shear stress decreases and approaches to the undisturbed shear stress, however, the turbulent intensity, the fluctuating pressure, and the vertical pressure gradient increase gradually.

关键词： scouring mechanism Large Eddy Simulation (LES) bed shear stress fluctuating pressure turbulent intensity

STABILITY ANALYSIS OF FINITE ELEMENT METHODS FORTHE ACOUSTIC WAVE EQUATION WITH ABSORBINGBOUNDARY CONDITIONS (PART I)

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Journal of Computational Mathematics 1999年第3期17卷 293-306页

作者： Xiu-min Shao Zhi-ling Lan(institute of Mathematics, academy of sciences, beijing 100080, china) 中科院数学所北京

In Part I and Part II of this paper initial-boundary value problems of the acoustic wave equation with absorbing boundary conditions are considered. Their finite element-finite difference computational schemes are proposed. The stability of the schemes is discussed and the corresponding stability conditions are given. Part I and Part II concern the first- and the second-order absorbing boundary conditions, respectively. Finally, numerical results are presented in Part II to show the correctness of theoretical analysis. (Author abstract) 7 Refs.

关键词： stability finite element methods wave equation absorbing boundary conditions

On factorizable solution of the differential equation(f')~2-a_0(z)(f-a)1(z))~2f

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chinese Science Bulletin 1997年第21期42卷 1779-1782页

作者： YUAN Wenjun and HE Yuzaninstitute of Mathematics, chinese academy of sciences, beijing 100080, china institute of Mathematics Chinese Academy of Sciences Beijing 100080 China

If the coefficients are transcendental, Bergweiler et al. proved that in all possible non-trivialfactorization f(z)=h(g(z)), the growth of the right factor g(z) can be controlled by thegrowth of the coefficients. In ref. [2], He and Laine proved a similar conclusion for two othertypical kinds of nonlinear differential equations. But for the following equation:

关键词： factorization growth order meromorphic function ordinary differential equation.

A New Chromogenic Diester-calix[4]crown Receptor for Ca^(2+)

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chinese Chemical Letters 1998年第11期9卷 993-996页

作者： Chuan Feng CHEN Qi Yu ZHENG Zhi Tang HUANG (institute of chemistry, chinese academy of sciences, beijing,100080) institute of chemistry Chinese Academy of Sciences Beijing 100080 China

A diester-calix[4]crown-4-ether bearing mono (azophenol) moiety shows a larger spectral change toward Ca2+ than other alkali and alkaline eafth cations.

关键词： Chromogenic receptor diester-calixcrown-4-ether, Ca^(2+)-selective.

Novel gaseous transient species:generation and characterization

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Science china chemistry 2007年第2期50卷 145-169页

作者： ZENG xiaoQing1,2 & WANG DianXun11 State Key Laboratory for Structural chemistry of Unstable and Stable Species,institute of chemistry,chinese academy of Sci-ences,beijing 100080,china 2 Graduate School of chinese academy of sciences,beijing 100039,china 1. State Key Laboratory for Structural chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China 2. Graduate School of chinese academy of sciences Beijing 100039 China

Due to special properties of transient species, such as short-lived, unstable, reactive, and even explosive, the generation and subsequent characterization is a great challenge for experimental chemists. In our laboratory, systematic researches have been carried out to investigate novel transient species: reactive halogen species (RHS), short-lived free radicals, and metastable pseudohalogen compounds, based on the successive technical improvements on the Hel Photoelectron spectroscopy (PES). In this review, the topic mainly focuses on innovative methods of generating novel transient species, and subsequent geometric and electronic structure characterizations of these species combined with quantum chemical calculations.

关键词： reactive halogen species radicals pseudohalogen compounds Hel Photoelectron Spectroscopy (PES) quantum chemical calculations

Quantitative Analysis of Seeing with Height and Time at Muztagh-Ata Site Based on ERA5 Database

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Research in Astronomy and Astrophysics 2024年第1期24卷 87-95页

作者： xiao-Qi Wu Cun-Ying xiao Ali Esamdin jing Xu Ze-Wei Wang Luo xiao institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Department of Astronomy Beijing Normal UniversityBeijing 100875China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of chinese academy of sciences Beijing 100049China

Seeing is an important index to evaluate the quality of an astronomical *** estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanalysis database(ERA5)is *** calculated from ERA5 is compared consistently with the Differential Image Motion Monitor seeing at the height of 12 *** show that seeing decays exponentially with height at the Muztagh-Ata *** decays the fastest in fall in 2021 and most slowly with height in *** seeing condition is better in fall than in *** median value of seeing at 12 m is 0.89 arcsec,the maximum value is1.21 arcsec in August and the minimum is 0.66 arcsec in *** median value of seeing at 12 m is 0.72arcsec in the nighttime and 1.08 arcsec in the *** is a combination of annual and about biannual variations with the same phase as temperature and wind speed indicating that seeing variation with time is influenced by temperature and wind *** Richardson number Ri is used to analyze the atmospheric stability and the variations of seeing are consistent with Ri between *** quantitative results can provide an important reference for a telescopic observation strategy.

关键词： site testing atmospheric effects methods:data analysis telescopes Earth