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CONSTRUCTION OF A PRECONDITIONER FOR DOMAIN DECOMPOSITION METHODS WITH POLYNOMIAL LAGRANGIAN MULTIPLIERS

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Journal of Computational Mathematics 2001年第2期19卷 213-224页

作者： Qi-ya Hu (Institute of Computational Mathematics, academy of Mathematics and Systems sciences, Chinese academy of sciences, Beijing 100080, China) Guo-ping Liang Jin-zhao Liu (Institute of Mathematics, academy of Mathematics and Systems sciences, Chinese 中科院计算数学与工程计算数学所北京 100080 中科院数学所北京 100080

In this paper we consider domain decomposition methods with polynomial Lagrangian multipliers to two-dimentional elliptic problems, and construct a kind of simple preconditioners for the corresponding interface equation. It will be shown that condition number of the resulting preconditioned interface matrix is almost optimal (namelys it has only logarithmic growth with dimension of the local interface space).

关键词： Domain Decomposition Non-matching grids Lagrangian multipliers Preconditioner Condition number.

THE L^2-NORM ERROR ESTIMATE OF NONCONFORMING FINITE ELEMENT METHOD FOR THE 2ND ORDER ELLIPTIC PROBLEM WITH THE LOWEST REGULARITY

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Journal of Computational Mathematics 2000年第3期18卷 277-282页

作者： Lie-heng Wang (LSEC, Institute of Computational Mathematics and Scientific/Engineering Computing, academy of Mathematics and System sciences, Chinese academy of sciences, Beijing, 100080, China) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京 100080

Presents the abstract L...-norm error estimate of nonconforming finite element method. Use of the Aubin Nitsche Lemma in estimating nonconforming finite element methods; Details on the equations.

关键词： L-2-norm error estimate nonconforming f.e.m. lowest regularity

ON THE CENTRAL RELAXING SCHEMES I:SINGLE CONSERVATION LAWS

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Journal of Computational Mathematics 2000年第3期18卷 313-324页

作者： Hua-zhong Tang (LSEC, Institute of Computational Mathematics and Scientific /Engineering Computing, academy of Mathematics and System sciences, Chinese academy of sciences, Beijing, 100080, China) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京 100080

Presents a central relaxing scheme for scalar conservation laws. Details on the preliminary equations; Properties of the relaxed schemes; Conclusions.

关键词： hyperbolic conservation laws the relaxing scheme TVD cell entropy inequality

Projection Effects on Physical Parameters Obtained from Solar Vector Magnetograms

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Chinese Journal of Astronomy and Astrophysics 2002年第2期2卷 174-182页

作者： Hui Li Purple Mountain Observatory, Chinese academy of sciences, Nanjing 210008 National Astronomical Observatories, Chinese academy of sciences, Beijing 100012 Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

Projection effects in Huairou solar vector magnetograms are corrected by transferring or mapping the observed vector magnetogram in the image plane to the heliographic plane (planar correction) and to the heliospheric coordinate system (spherical correction). The magnetograms after the correction are considerably dif- ferent. The planar correction and the spherical correction lead to slightly different magnetic configurations, especially when the active region involved is far from the disk center. We also discuss the effects of the corrections on magnetic activity pa- rameters, such as magnetic shear, current helicity, etc. It is shown that the neutral line is obviously distorted after the mapping. The mapping generally decreases the average shear angle on the neutral line by several degrees when the active region is in the eastern hemisphere, and increases it when in the western hemisphere. In most of the cases studied, the correction reduces the current helicity imbalance, and sometimes even changes its sign. It is found that the current helicity imbalance may change its sign in its evolution when there are apparent fluxes emerging from the lower photosphere. The corrections increase the noise level of Bz greatly, and decrease the noise level of B~ slightly. The accuracy of the magnetic field measure- ment at Huairou is estimated to be better than 20 G and 150 G for the longitudinal and the transverse component, respectively.

关键词： Sun: magnetic fields ─Sun: activity ─Sun: photosphere

The first cohomology group of trivial extensions of special biserial algebras

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Science China Mathematics 2004年第4期47卷 578-592页

作者： XU YungeDepartment of Mathematics & Computer sciences, hubei University, Wuhan 430062, China Department of Mathematics & Computer sciences Hubei University Wuhan China Institute of Mathematics Chinese Academy of Sciences Beijing China

Given a finite dimensional special biserial algebra A with normed basis we obtain the dimension formulae of the first Hochschild homology groups of A and the vector space Alt(DA). As a consequence, an explicit dimension formula of the first Hochschild cohomology group of trivial extension TA = A × DA in terms of the combinatorics of the quiver and relations is determined.

关键词： Hochschild (co)homology, trivial extension, special biserial algebra.

Vilnius Photometry and Reddening of the Young Open Cluster NGC 6913

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Chinese Journal of Astronomy and Astrophysics 2001年第4期1卷 333-343页

作者： Jun-Jie Wang and Jing-Yao Hu (National Astronomical Observatories, Chinese academy of sciences, Beijing 100012 Beijing Astronomical Observatory, Chinese academy of sciences, Beijing 100012 Chinese academy of sciences-Peking University Joint Beijing As National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Beijing Astronomical Observatory Chinese Academy of Sciences Beijing 100012 Chinese academy of sciences-Peking University Joint Beijing Astrophysical Center Beijing 100871

stars in the NGC 6913 field with both UBV and Vilnius photometry are selected to be the sample. The membership probability of the stars is greater than 50%. The correlation among Vilnius photometry, UBV photometry and reddening in the cluster is reviewed. It is found that the photometry in the Vilnius X, Y and Z bands can be used to make rough spectral classification. The values of E(B - V) are well correlated with the Vilnius colors of X - Y, Y - Z, Z - V and V - S in NGC 6913. The ratio of (V - S)/(Y - Z) of the MPCM (Most Possible Cluster Members) is a constant (1.30 -±0.06), and has no effect on the values of E(B - V), (B - V)0 and V0. Comparing with the observational data of all the stars of NGC 6913 region, we propose that the value of (V - S)/(Y - Z) can probably be used to select the preliminary candidates of one open cluster. In addition, 12 variable stars are discovered in the NGC 6913 region, in which star #155 has a variation with an amplitude of 4.25 mag.

关键词： Galaxy: open clusters and associations - ISM: dust extinction

Cloning of fatty acid elongase1 gene and molecular identification of A and C genome in Brassica species

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Science China(Life sciences) 2007年第3期50卷 343-349页

作者： WU YuHua, XIAO Ling, WU Gang & LU ChangMing Oil Crops Research Institute, Chinese academy of agricultural sciences, Wuhan 430062, China Oil Crops Research Institute Chinese Academy of Agricultural Sciences Wuhan China

The fatty acid elongase 1 (FAE1) genes of Brassic napus were cloned from two cultivars, i.e. Zhong- shuan No. 9 with low erucic acid content, and Zhongyou 821 with high erucic acid content, using the degenerate PCR primers. The sequence analysis showed that there was no intron within the FAE1 genes. The FAE1 genes from Zhongyou 821 contained a coding sequence of 1521 nucleotides, and those cloned from Zhongshuan No. 9 contained a 1517 bp coding sequence. Alignment of the FAE1 sequences from Brassica rapa, B. oleracea and B. napus detected 31 single nucleotide polymorphic sites (2.03%), which resulted in 7 amino-acid substitutions. Further analysis indicated that 19 SNPs were genome-specific, of which, 95% were synonymous mutations. The nucleotide substitution at po- sition 1217 in the FAE1 genes led to a specific site of restricted cleavage. An AvrII cleavage site was present only in the C genome genes and absent in the A genome FAE1 genes. Digestion profile of the FAE1 sequences from B. rapa, B. oleracea and B. napus produced with AvrII confirmed that the FAE1 genes of B. oleracea origin was recognized and digested, while that of B. rapa origin could not. The results indicated that by AvrII cleavage it was possible to distinguish B. rapa from B. oleracea and be- tween the A and C genome of B. napus. In addition, the FAE1 genes could be used as marker genes to detect the pollen flow of B. napus, thus providing an alternative method for risk assessment of gene flow.

关键词： FAE acid Cloning of fatty acid elongase1 gene and molecular identification of A and C genome in Brassica species gene

Molecular Diversity of the 5S rRNA Gene in Cultivated and Wild Rice Species

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Wuhan University Journal of Natural sciences 1998年第1期3卷 119-122页

作者： Yi Qingming,Xia Zongping,Yuan Pingrong(College of Life sciences,Wuhan University, Wuhan 430072,China)(Yunnan academy of agricultural sciences,Kunmin 650221,China) College of Life sciences Wuhan University Wuhan China Yunnan academy of agricultural sciences Kunmin China

We have used the polymerase chain reaction to analyze variation in the size of 5S ribosomal gene spacer sequence. Eighty accessions, including 65 cultivated rice and 15 wild rice, were analyzed. Among them seven size classes of 5S DNA spacer were observed. Classification asindica orjaponica on the basis of 5S DNA spacer patterns generally agrees with classification based on morphological studies, indicating that the length polymorphism of 5S DNA spacer could be used as a molecular marker for taxonomic and phylogenetic analysis.

关键词： rice 5S DNA PCR

Novel alleles among soybean Bowman-Birk proteinase inhibitor gene families

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Science China(Life sciences) 2008年第8期51卷 687-692页

作者： WANG YuePing1,2, CHEN XiongTing2 & QIU LiJuan1 1 National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Crop Germplasm & Biotechnology(MOA)/Institute of Crop Science, Chinese academy of agricultural sciences, Beijing 10008, China 2 Institute of Tropical Biotechnology, Chinese academy of Tropical agricultural sciences, Haikou 571101, China National Key Facility for Crop Gene Resources and Genetic Improvement Key Laboratory of Crop Germplasm & Biotechnology (MOA)/Institute of Crop Science Chinese Academy of Agricultural Sciences Beijing China Institute of Tropical Biotechnology Chinese Academy of Tropical Agricultural Sciences Haikou China

Trypsin inhibitors have been found in various animals, plants and *** were two types of trypsin inhibitors in soybean including Bowman-Birk protease inhibitors(BBI) and Kunitz in-hibitors(KTI).The different BBI genes from wild soybean(***) and cultivated soybean(***) formed a multigene *** constructed a cDNA library of cultivar 'SuiNong 14' seed at the R7 growth stage using the SMART *** contigs or singletons were highly homologous to soy-bean protease *** of 5, 35, 8 and 9 were highly homologous to BBI family members BBI-A1, BBI-A2, BBI-C and BBI-D, *** analyses showed there were novel allelic varia-tions among the 4 BBI members in SuiNong *** on the comparison of soybean seed cDNA li-braries from different developmental stages, it was apparent that the expression of trypsin inhibitors increased during seed development in *** analysis of BBI gene sequences among dicotyledonous and monocotyledonous plants demonstrated that these genes shared a common pro-genitor.

关键词： soybean trypsin inhibitor Bowman-Birk proteinase inhibitor Kunitz trypsin inhibitor allelic variation