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ANALYSING THE EFFICIENCY OF SOLVING DENSE LINEAR EQUATIONS ON DWNING1000

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Journal of Computational Mathematics 1996年第4期14卷 383-386页

作者： X.B. Chi(institute of Software, chinese academy of sciences, Beijing, china) 中科院软件所北京

In this paper, we consider solving dense linear equations on Dawning1000 byusing matrix partitioning technique. Based on this partitioning of matrix, we give aparallel block LU decomposition method. The efficiency of solving linear equationsby different ways is analysed. The numerical results are given on *** running our parallel program, the best speed up on 3. processors is over 25.

关键词： ANALYSING THE EFFICIENCY OF SOLVING DENSE LINEAR EQUATIONS ON DWNING1000

Transformations and non-degenerate maps

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Science china Mathematics 2005年第Z1期48卷 195-205页

作者： LI Baokui & WANG Yuefei institute of Mathematics, academy of Mathematics and System sciences,{3., Beijing 100080, china Graduate School,{3., Beijing 100080, china institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China

We shall prove the equivalences of a non-degenerate circle-preserving map and a M(o)bius transformation in ^Rn, of a non-degenerate geodesic-preserving map and an isometry in Hn of a non-degenerate line-preserving map and an affine transformation in Rn. That a map is non-degenerate means that the image of the whole space under the map is not a circle, or geodesic or line respectively. These results hold without either injective or surjective, or even continuous assumptions, which are new and of a fundamental nature in geometry.

关键词： M(o)bius transformation, circle-preserving map, non-degenerate map.

ELTA-WAVE IN A SIMPLE 1-D 2 x 2 HYPERBOLIC PROBLEM

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Journal of Computational Mathematics 1996年第4期14卷 311-318页

作者： S.L. Yang(institute of Applied Mathematics, chinese academy of sciences, Beijing, china) institute of Applied Mathematics Chinese Academy of Sciences Beijing China

A simple one-dimensional 2 x 2 hyperbolic system is considered in the *** model contains a linear hyperbolic equation, as well as a hyperbolic equation ofwhich the coefficients are about the solution of the linear one. The exact solution ispresented and discussed, then numerical experiments are given by TVD (or MmB)type schemes for Riemann problems. From the results, we know that the solutionsdo have δ-waves for some suitable initial data.

关键词： Zhang Figure DELTA-WAVE IN A SIMPLE 1-D 2 HYPERBOLIC PROBLEM

δ-WAVE FOR 1-D AND 2-D HYPERBOLIC SYSTEMS

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Journal of Computational Mathematics 1996年第3期14卷 256-262页

作者： S.L. Yang(institute of Applied Mathematics, chinese academy of sciences, Beijing, china) 中科院应用数学所北京

Here a new kind of nonlinear wave, which is called δ-wave, is described by some high resolution difference solutions for Riemann problems of one-dimensional (1-D) and two-dimensional (2-D) nonlinear hyperbolic systems in conservation laws. Some phenomena are numerically shown for the solutions of Riemann problems for 2-D gas dynamics systems

关键词： Zhang WAVE FOR 1-D AND 2-D HYPERBOLIC SYSTEMS

Application of the moist vorticity vector in the analysis of a heavy rainfall event in North china

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Progress in Natural Science:Materials International 2007年第12期17卷 1457-1465页

作者： Zhao Yu1,2,3. Wang Jianguo4 and Xue Deqiang2(1. Laboratory of Cloud-Precipitation physics and Severe Storms, institute of Atmospheric physics,{3., Beijing 100029, china 2. Shandong Provincial Meteorological Observatory, Jinan 25003., china 3. Graduate University of{3., Beijing 10003., china 4. Shandong Provincial Meteorological Bureau, Jinan 25003., china) Laboratory of Cloud-Precipitation physics and Severe Storms Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Shandong Provincial Meteorological Observatory Jinan 250031 China Graduate University Chinese Academy of Sciences Beijing 100039 China Shandong Provincial Meteorological Bureau Jinan 250031 China

The moist vorticity vector (MVV), defined as (ζa×▽qv)/ρ introduced by Gao et al. is used to study a heavy rainfall event in North china. The MVV has zonal, meridional and vertical components in a three-dimensional framework. Analysis of domain-mean and mass-integrated quantities shows that the variation of the vertical component of the MVV closely follows the variation of the cloud hydrometeors, with a linear correlation coefficient of 0.95, indicating that the vertical component of the MVV is strongly associated with midlatitude convection. Further analysis shows that the vertical component of the MVV reflects the interaction between the horizontal vorticity and the horizontal specific humidity gradient, which can associate dynamic and thermodynamic processes with cloud microphysical processes. Thus, this study can help to understand how the interaction between circulations and clouds aids the development of convection, and the MVV can be used to trace the development and evolution of heavy rainfall.

关键词： moist vorticity vector heavy rainfall modeling study.

Applications of URANS on predicting unsteady turbulent separated flows

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Acta Mechanica Sinica 2009年第3期25卷 319-324页

作者： Jinglei Xu Huiyang Ma Department of physics, Graduate University of the chinese academy of sciences, 100049 Beijing, china Department of physics Graduate University of the Chinese Academy of Sciences Beijing China

Accurate prediction of unsteady separated turbulent flows remains one of the toughest tasks and a practi cal challenge for turbulence modeling. In this paper, a 2D flow past a circular cylinder at Reynolds number 3.900 is numerically investigated by using the technique of unsteady RANS （URANS）. Some typical linear and nonlinear eddy viscosity turbulence models （LEVM and NLEVM） and a quadratic explicit algebraic stress model （EASM） are evaluated. Numerical results have shown that a high-performance cubic NLEVM, such as CLS, are superior to the others in simulating turbulent separated flows with unsteady vortex shedding.

关键词： URANS Nonlinear eddy viscosity turbulencemodel ,Separated flows Circular cylinder

An improved δ-Eddington approximation

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chinese Science Bulletin 1999年第4期44卷 304-309页

作者： QIU Jinhuaninstitute of Atmospheric physics , chinese academy of sciences , Beijing 100029,{3. institute of Atmospheric physics Chinese Academy of Sciences Beijing China

Based on an accuracy analysis of two-stream approximations, an improved δ-Eddington ap-proximation is developed. The approximation has much better accuracy than all exiting two-stream ap-proximations as the optical depth is less than unity. As the surface reflectance is zero and the opticaldepth is less than unity, errors in both transmission and reflection calculated by the present approxima-tion are more one time less than those by other two-stream approximations. In the case of aerosol opti-cal depth of3.5% and 2.6%, respectively. The errors are over 41% and one times lessthan those by Eddington or δ-Eddington.

关键词： radiation flux fractional factor of δ-function Eddington approximation.

Mass Spectrometric Evidence of Heparin Disaccharides for the Catalytic Characterization of A Novel Endolytic Heparinase

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Acta Biochimica et Biophysica Sinica 2004年第12期36卷 840-844页

作者： Yapeng CHAO1,3. Shaoxiang XIONG2, Xiulan CHENG1, and Shijun QIAN1* 1institute of Microbiology, chinese academy of sciences, Beijing 100080, china 2Center of Mass Spectrometry, institute of Chemistry, chinese academy of sciences, Beijing 100080, china 3.raduate School of the chinese academy of sciences, Beijing 10003., china institute of Microbiology Chinese Academy of SciencesBeijing 100080 China Graduate School of the chinese academy of sciencesBeijing 10003. China Center of Mass Spectrometry Institute of Chemistry Chinese Academy of SciencesBeijing 100080 China

Heparinase from different sources can eliminate heparin or/and heparan sulfate into various low-molecular weight heparins with different characteristics. Porcine intestinal mucosa heparin was de- graded into a series of oligosaccharides by a novel heparinase from the species Sphingobacterium. Disaccha- ride components from the digests were separated and purified by ultrafiltration and HPLC. Five major peaks appeared as three types according to their retention time. The mass spectrometry of peak I mainly gave the non-sulfated disaccharide with the mass of 3.9 Da. Peak II and III were indicated as two major monosulfated disaccharides with molecular mass of 417 and 459 Da respectively. Moreover, the peak III represented an N- acetyl disaccharide. Both peak IV and V showed the same mass of 496 Da, hinting that they were disulfate- substituted disaccharides. No trisulfate-substituted disaccharides were detected in the mixture of the heparin digest though they were abundant in the heparin structure. The results revealed that the heparinase might specifically cut the sites with low sulfated domain in heparin.

关键词： electrospray ionization-mass spectrometry heparin disaccharides heparinase high perfor- mance liquid chromatography Sphingobacterium sp.

Morphological characteristics of leaf epidermis and size variation of leaf,flower and fruit in different ploidy levels in Buddleja macrostachya (Buddlejaceae)

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Journal of Systematics and Evolution 2009年第3期47卷 231-236页

作者： 1,2Gao CHEN 1Wei-Bang SUN 3.ang SUN 1(Kunming Botanical Garden, Kunming institute of Botany, chinese academy of sciences, Kunming 650204, china) 2(Graduate School of chinese academy of sciences, Beijing 100049, china) 3.Key Laboratory of Biodiversity and Biogeography, Kunming institute of Botany, chinese academy of sciences, Kunming 650204, china) (Kunming Botanical Garden Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 China) (Graduate School of chinese academy of sciences Beijing 100049 China) (Key Laboratory of Biodiversity and Biogeography Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 China)

Buddleja macrostachya (Buddlejaceae) is a widespread shrub native to the Sino-Himalayan mountains and beyond. It has been found to occur at two ploidy levels, hexaploid, 2n=6x=114 and dodecaploid, 2n=12.=228. To determine if morphological characters might be used as indicators of ploidy levels, we measured floral and fruit length, relative and absolute leaf size, trichome density on both leaf surfaces, and stomatal density and length in different populations of B. macrostachya. In general, flower and fruit length, absolute leaf size, and stomatal length increased with an increase at ploidy level (P0.05) in different populations. Other characters studied such as trichome type, cuticular membrane and ornamentation of stomata, cell and stomatal shape, and anticlinal wall pattern were quite constant in this species. Thus it appears that flower and fruit length, absolute leaf size, and stomatal frequency and length can be used to distinguish hexaploid from dodecaploid cytotypes either in the fleld or in herbarium specimens.

关键词： Buddleja macrostachya dodecaploid hexaploid leaf epidermis ploidy level stomata.