检索结果-南通市图书馆

Phylogeny and species delimitation of the C-genome diploid species in Oryza

Journal of Systematics and Evolution 2011年第5期49卷 386-395页

作者： 1,2~Li-Li ZANG 1~Xin-Hui ZOU 1~Fu-Min ZHANG 3.4~Ziheng YANG 1,2~Song GE 1(State Key Laboratory of Systematic and Evolutionary Botany,Institute of Botany,chinese academy of sciences,{3. 100093.china) 2(Graduate University of the chinese academy of sciences,{3. 100049,china) 3.Department of Biology,University College London,London WC1E 6BT,United Kingdom) 4(center for Computational and Evolutionary Biology,Institute of Zoology,chinese academy of sciences,{3. 100101,china) (State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of the chinese academy of sciences Beijing 100049 China) (Department of Biology University College London London WC1E 6BT United Kingdom) (center for Computational and Evolutionary Biology Institute of Zoology Chinese Academy of Sciences Beijing 100101 China)

The diploid Oryza species with C-genome type possesses abundant genes useful for rice improvement and provides parental donors of many tetraploid species with the C-genome(BBCC,CCDD).Despite extensive studies,the phylogenetic relationship among the C-genome species and the taxonomic status of some taxa remain *** this study,we reconstructed the phylogeny of three diploid species with C-genome(Oryza officinalis,***,and ***) based on sequences of 68 nuclear single-copy *** obtained a fully resolved phylogenetic tree,clearly indicating the sister relationship of *** and ***,with *** being the more divergent *** phylogenies of the C-genome species found in previous studies might result from lineage sorting,introgression/hybridization and limited number of genetic markers *** further applied a recently developed Bayesian species delimitation method to investigate the species status of the Sri Lankan and African *** of two datasets(68 genes with a single sample,and 10 genes with multiple samples) support the distinct species status of the Sri Lankan and African *** addition,we evaluated the impact of the number of sampled individuals and loci on species *** simulation suggests that sampling multiple individuals is critically important for species delimitation,particularly for closely related species.

关键词： Bayesian species delimitation Oryza phylogeny taxonomy.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Approximation Theorem of Convolution Operator in △~p Set-valued Function space

引用

Acta Mathematicae Applicatae Sinica 2002年第3期18卷 495-500页

作者： Pei-xin YeInstitute of Mathematics, academy of Mathematics and System sciences, chinese academy of science, beijing Institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Science Beijing 100080 China

The paper is a contribution to the problem of approximating random set with values in a separable Banach space. This class of set-valued function is widely used in many *** investigate the properties of p-bounded integrable random set. Based on this we endow it with △p metric which can be viewed as a integral type hausdorff metric and present some approximation theorem of a class of convolution operators with respect to △p metric. Moreover we also can establish analogous theorem for other integral type operator in △p space.

关键词： Set-valued function random set convolution operator △~p space approximation theorem

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

space MATERIALS science

引用

空间科学学报 1998年第S1期18卷 104-111页

作者： CHEN Wan-chun Wei B.(Institute of Physics, The chinese academy of sciences,{3.)(Department of applied Physics in Northwestern Polytechnical Univerity)

The main studying activities and results on space materials science during 1996-1997 in china were summarized. The typical {3. subjects are crystal growth from melt, crystal growth from solution, nucleation, undercooling,solidification of alloys and space experimental hardware. They are carried out by the ground-based studies, the short duration microgravity missions and orbital experiments.

关键词： space materials science Crystal growth Solidification Microgravity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Two new types of bounded waves of CH-γ equation

引用

science china Mathematics 2005年第12期48卷 1618-1630页

作者： GUO Boling & LIU Zhengrong Institute of applied Physics and Computational Mathematics, beijing 100088, china School of Mathematical {3.s and center for Nonlinear {3. Studies, South china University of Technology, Guangzhou 510640, china Institute of applied Physics and Computational Mathematics Beijing China School of Mathematical sciences and center for Nonlinear science Studies South China University of Technology Guangzhou China

In this paper, the bifurcation method of dynamical systems and numerical approach of differential equations are employed to study CH-γ equation. Two new types of bounded waves are found. One of them is called the compacton. The other is called the generalized kink wave. Their planar graphs are simulated and their implicit expressions are given. The identity of theoretical derivation and numerical simulation is displayed.

关键词： CH-γ equation,compactons,generalized kink waves.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Determination of Young's modulus by nanoindentation

引用

science china(Technological sciences) 2004年第4期47卷 398-408页

作者： MA Dejun1, Chung Wo Ong2, LIU Jianmin1 & HE Jiawen3.1. Surface Engineering research Institute, CMES, beijing 100072, china 2. Department of {3. Physics and Materials research center, The Hong Kong Polytechnic University, Hong Kong, china 3. State Key Laboratory for Mechanical Behavior of Materials, Xian Jiaotong University, Xian 710049, china Surface Engineering research Institute CMES Beijing China Department of applied Physics and Materials research center The Hong Kong Polytechnic University Hong Kong China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University Xi’an China

A methodology for determining Youngs modulus of materials by non-ideally sharp indentation has been developed. According to the principle of the same area-to-depth ratio, a non-ideally pyramidal indenter like a Berkovich one can be approximated by a non-ideally conical indenter with a spherical cap at the tip. By applying dimensional and finite element analysis to the non-ideally conical indentation, a set of approximate one-to-one relationships between the ratio of nominal hardness/reduced Youngs modulus and the ratio of elastic work/total work, which correspond to different tip bluntness, have been revealed. The nominal hardness is defined as the maximum indentation load divided by the cross-section area of the conical indenter specified at the maximum indentation depth. As a consequence, Youngs modulus can be determined from a nanoindentation test only using the maximum indentation load and depth, and the work done during loading and unloading processes. The new method for determining Youngs modulus is referred to as pure energy method. The validity of the method was examined by performing indentation tests on five materials. The experimental results and the standard reference values are in good agreement, indicating that the proposed pure energy method is a promising substitution for the most widely used analysis models at present.

关键词： Young's modulus, nanoindentation, nominal hardness, indentation work.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application and Comparison of SST Model in Numerical Simulation of the Axial Compressors

引用

Journal of Thermal science 2010年第4期19卷 300-309页

作者： YIN Song~1,JIN Donghai~2,GUI Xingmin~3.and ZHU Fang Aero-Engines Simulation research center,School of Jet Propulsion,beijing University of Aeronautics and Astronautics, beijing,100191,china Aero-Engines Simulation research center School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing China

The shear-stress transport(SST)turbulence model is incorporated into Navier-Stokes equations to simulate a turbomachinery flowfield.A staggered finite volume method is used to make the mean flow equations and turbulence model equations strongly coupled and enhance the stability of the numerical *** implicit treatment of the source terms is applied to the SST model.A steady state solution is obtained using five-stage Runge-Kutta time-stepping scheme with local time stepping and residual smoothing to accelerate convergence. The wall distance d,a key parameter in the SST model,is solved by a partial differential *** validations of the code are conducted on rotor 3.,wp11 at design and off-design conditions by comparison with measurements and the Spalart-Allmaras(SA)turbulence *** flow within the tip is calculated with a multi-block grid.

关键词： SST model staggered finite volume method turbomachinery simulation multi-block grid

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Uniform design over a convex polyhedron

引用

chinese science Bulletin 1999年第2期44卷 112-114页

作者： FANG Kaitai , TIAN Guoliang XIE Minyu Hong Kong Baptist University, Kowloon, Hong Kong, china Institute of applied Mathematics, chinese {3. of sciences, beijing 100080, china Central china Normal University, Wuhan 43.070, chinaCorresponding author: Present address: Department of Probability and Statistics, Peking University, beijing 100871, china Hong Kong Baptist University Hong Kong China Institute of applied Mathematics Chinese Academy of Sciences Beijing China Central china Normal University Wuhan China

A new method, called the simplex method, is proposed to generate the uniform design over a convex polyhedron in n-dimensional Euclidean

关键词： convex polyhedron experimental design uniform design.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Crystallization Mechanism of Na_2O-CaO-Al_2O_3.SiO_2-F Glass Containing Cr_2O_3

引用

International Journal of Minerals,Metallurgy and Materials 1999年第3期13卷 214-218页

作者： Lidong Teng Fuming Wang Wenchao Li(Department of inorganic Materials, Shandong Institute of Light Industry, Jinan 250100, china)(applied science School, University of science and Technology beijing, beijing 100083. china) Department of Inorganic Materials Shandong Institute of Light Industry Jinan 250100 China applied science School University of Science and Technology Beijing Beijing 100083 China

The effect of Cr2O3.on the nucleation and crystallization of Na2O-CaO-Al2O3.SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specrometer) and so on. Computer pattern recognition is applied to optimize the heat-treatment schedules. The experimental results show that the base glass containing more than 1 .5 % (mass fraction) Cr2O3.can be nucleated internally and converted to spheroidal crystal glass materials. The spheroidal crystal consisted of fibrous wollastonite crystals radiating from a center. The residual glass phase filled in the interstices between the fibers and between the spherulites. During heat treatment process, the valence states ofchromium changed from Cr6- to Cr3., and the Cr-spinel solidsolution [CaCr2O4] precipitated followed this valence change. At the primary stage of crystallization, the Cr-spinel could act as a nucleating center on which the principal or}stalline phase β-CaSiO3.grew epitaxially.

关键词： crystallized glass Na_2O-CaO-Al_2O_3.SiO_2 Cr_2O_3 pattern recognition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Novel synergic combinatorial photoelectrochemical technology for degradation of trace of 2-chlorophenol in drinking water

引用

chinese science Bulletin 2003年第8期48卷 751-757页

作者： SONG Qiang & QU Jiuhui State Key Lab. of Environmental Aquatic Chemistry, research center for Eco-environmental science, {3. academy of sciences, beijing 100085, china Correspondence should be addressed to Qu Jiuhui (e-mail: jhqu@ ***) State Key Lab. of Environmental Aquatic Chemistry Research Center for Eco-environmental Science Chinese Academy of Sciences Beijing 100085 China

A novel combinatorial photoelectrochemical (CPE) technology with combination of ultraviolet (UV)- photolysis and direct current (DC) electrolysis is studied and discussed for drinking water purification. In the self-made compositive photo-electrolysis incorporate reactor, removal rate of the 2-chlorophenol as model environmental pollutants has been investigated experimentally in terms of applied voltage, pH value, flow velocity, temperature, and aeration conditions. A primary analysis of the combinatorial photo-electric synergic effect on the degradation of organic pollut-ants has been carried out. It is found that the best perform-ance of CPE oxidation is achieved by the following condi-tions: DC voltage of 5.0 V combined with UV-254-raidation, near neutral of pH 8 with aeration of pure oxygen. The in-fluences of circular velocity, temperature, and initial concen-tration of the pollutant are minor. Under the optimal condi-tions, removal ratio of 2-CP is higher than 50% in 3. min, and 100% removal ratio of 2-CP (5 10-6) can be reached and TOC removal ratio reached above 90% in 2.5 h. Com-plete mineralization is achieved eventually. It shows in our investigation that under the studied conditions the synergic effect of UV photolysis and DC electrolysis on the degrada-tion of the model pollutant is remarkable and validated, which may be derived from the coexistence of mutual com-plementary mechanisms of photoelectrochemical action, and the radicals chain reactions resulted from photo activation and electrolysis excitation in the process of CPE oxidation.

关键词： 2-氯酚饮用水处理组合光电化学技术 CPE 紫外线

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

卫星网络仿真系统建模的研究

引用

计算机工程与应用 2004年第23期40卷 142-144,208页

作者：王曦爽孟新中国科学院空间科学与应用研究中心北京100080

提出了建立一个卫星网络仿真模型的基本架构,分析了如何构造卫星网络仿真模型的卫星拓扑结构、如何仿真空间环境下卫星网络通信链路、如何表现空间环境特点对卫星网络的影响等问题,并通过对一个小卫星网络与地面终端的通信过程的仿真实... 详细信息

提出了建立一个卫星网络仿真模型的基本架构,分析了如何构造卫星网络仿真模型的卫星拓扑结构、如何仿真空间环境下卫星网络通信链路、如何表现空间环境特点对卫星网络的影响等问题,并通过对一个小卫星网络与地面终端的通信过程的仿真实现验证了架构方案的可靠性。

关键词：卫星网络网络仿真仿真架构 NS 卫星拓扑结构

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：