检索结果-南通市图书馆

Resolution of α-cyclohexyl-mandelic acid enantiomers by two-phase (O/W) recognition chiral extraction

science china Chemistry 2007年第6期50卷 764-769页

作者： TANG KeWen1,2, ZHANG GuoLi2, HUANG KeLong2, LI Yuanjian3 & YI JianMin1,2 1 Department of Chemistry and Chemical Engineering, Hunan Institute of science and Technology, Yueyang 414000, china 2 college of Chemistry and Chemical Engineering, central south university, changsha 410083, china 3.college of pharmaceutical science, central south university, changsha 410078, china Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414000China college of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China

This paper presents a new chiral separation technology:two-phase(O/W)recognition chiral *** behavior of alpha-cyclohexyl-mandelic acid enantiomers was studied in the extraction system with D(L)-isobutyl tartrate in 1,2-dichloroethane organic phase and beta-CD derivatives in aqueous phase,and the influence of the kind and concentration of extractant and pH on extraction performance was *** experimental results indicate that two-phase(O/W)recognition chiral extraction is of strong chiral separation ***-^-CD,HE-beta-CD and Me-beta-CD have higher recognition ability for S-CHMA than that for R-CHMA,among which HP-beta-CD has the strongest ability;whereas,D-isobutyl tartrate has reversed recognition ability for *** the extraction system containing HP-beta-CD and D-isobutyl tartrate,e.e.% of S-CHMA in aqueous phase reached 27.6% by one stage extraction,and the distribution ratio for R-CHMA(k_R)and for S-CHMA(k_S)and separation factor(alpha)are 2.44,0.89 and 2.49,***,pH and concentration of extractant have great effects on chiral separation ***-phase(O/W)recognition chiral extraction has great significance for preparative separation of racemic compounds.

关键词： two-phase(W/0)recognition chiral extraction alpha-cyclohexyl-mandelic acid enantiomers

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

Survival probability and ruin probability of a risk model

引用

Applied Mathematics(A Journal of Chinese Universities) 2008年第3期23卷 256-264页

作者： LUO Jian-hua college of science,central south university of Forestry and Technology,changsha 410004,china Institute of Statistics,central south university of Forestry and Technology,changsha 410004,china. college of science Central South University of Forestry and Technology Changsha 410004 China Institute of Statistics Central South University of Forestry and Technology Changsha 410004 China

In this paper, a new risk model is studied in which the rate of premium income is regarded as a random variable, the arrival of insurance policies is a Poisson process and the process of claim occurring is p-thinning process. The integral representations of the survival probability are gotten. The explicit formula of the survival probability on the infinite interval is obtained in the special casc cxponential *** Lundberg inequality and the common formula of the ruin probability are gotten in terms of some techniques from martingale theory.

关键词： risk model thinning process survival probability martingale ruin probability integral representation

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

Drag reduction of flow boiling with polymer additives

引用

Journal of central south university of Technology 2001年第2期8卷 143-146页

作者： QIU Yun ren 1,CHEN Wei ping 2,SI Qin 3 (1.college of Chemistry and Chemical Engineering, central south university, changsha 410083, china 2.Editorial Office of Journal of central south university, changsha 410083, china 3.college of Chemical E 1. college of Chemistry and Chemical Engineering Central South University 410083 Changsha China 2. Editorial Office of Journal of central south university 410083 Changsha China 3. college of Chemical Engineering Tianjin University 300072 Tianjin China

The drag reducing effect of polymer additive aqueous solution was investigated in flow boiling, and the polymer additives were two kinds of polyacrylamide (PAM) with relative molecular mass about 2.56×10 6 and 8.55×10 6. The frictional pressure drop was calculated according to the measured total pressure drop. The results show that the flow drag of flow boiling is reduced by adding a small amount of PAM to water when heat flux is in the range of 15.1 kW·m -2 to 47.0 kW·m -2 , when the mass fraction of PAM is higher than 2.0×10 -5 , the drag reducing effect is obvious. Drag reducing effect of PAM, whose relative molecular mass is 8.55×10 6, is slightly better than that of 2.56×10 6 at the same mass fraction, and the greater the flow rate of the additive solution, the better the effect of the drag reduction.

关键词： polymer additive flow boiling drag reduction pressure drop

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

Characteristic atom arranging crystallogphy of alloy phases for Au-Cu system

引用

science china(Technological sciences) 2011年第6期54卷 1560-1567页

作者： XIE YouQing1,2,3,LIU XinBi1,2,3,PENG HongJian4,NIE YaoZhuang5,LI XiaoBo6 & LI YanFen1,2,3 1 School of Materials science and Engineering,central south university,changsha 410083,china 2 Powder Metallurgy Research Institute,central south university,changsha 410083 china 3 State Key Laboratory of Powder Metallurgy,central south university,changsha 410083,china 4 School of Chemistry and Chemical Engineering,central south university,changsha 410083,china 5 School of Physical science and Technique,central south university,changsha,410083,china 6 college of Mechanical Engineering,Xiangtan university,Xiangtan 411105,china 1. School of Materials science and Engineering Central South University Changsha 410083 China2. Powder Metallurgy Research Institute Central South University Changsha 410083 China3. State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China4. School of Chemistry and Chemical Engineering Central South University Changsha 410083 China5. School of Physical Science and Technique Central South University Changsha 410083 China6. College of Mechanical Engineering Xiangtan University Xiangtan 411105 China

In this paper,it is pointed out that the descriptions of alloy phase structures are dependent on structural unit *** the systematic science of alloys(SSA),the alloy phase structures are described by means of the symmetry element sequence combining with characteristic atom *** is named the characteristic atom arranging structure,which can display the characteristic atoms at the lattice sites and the micro-inhomogeneity,besides the *** characteristic atom has its own characters:neighboring configuration,potential energy,volume and electronic *** micro-inhomogeneity of alloy phases can be described by concentrations and short-range ordered parameters of characteristic *** differences between the electronic structures of alloy phases and electronic structures of characteristic atoms in the alloy phases are also discussed.

关键词： systematic science of alloys Au-Cu system alloy phase structure micro-inhomogeneity

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

Training, simulation, restoration expert system for power grid

引用

Journal of central south university of Technology 2001年第1期8卷 69-73页

作者： LUO An,CHEN Qian (college of Information Engineering, central south university, changsha 410083, china) 1. college of Information Engineering Central South University 410083 Changsha China

The paper introduces some technology for training, simulation, restoration expert system of power grid, the structure of the system including function composition, hardware and software composition are discussed, knowledge representation and the method to establish device graphical library for expert system are given, the fault setting and diagnosis for training and simulation as well as restoration technology with deep first searching arithmetic and heuristic inference are presented. The research provides a good base for developing the training, simulation, restoration system of power companies.

关键词： training simulation restoration expert system power 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

Synthesis and purification of trialkyl compounds of gallium and indium

引用

Rare Metals 2002年第1期21卷 1-6页

作者： SHU Wangen, ZHOU Zhongcheng and LI Xiong Chemistry and Chemical Engineering college, central south university, changsha 410083, china Chemistry and Chemistry Engineering college Central South University Changsha 410083 Chemistry and Chemical Engineering college Central South University Changsha 410083

The The research progress in trialkyl compounds of gallium andindium was discussed from two aspect, one was the chemical synthesisof the compounds and the other was the purification of them. Thereare three synthesis routes be- ing reported in the first aspect, *** route staring form pure metal, the route starting from the puremetal trihalides, and the electrochemical route. In the secondaspect, the purifying methods of decomposition-distillation and zonerefining were reviewed.

关键词： trialkyl compounds gallium nd indium synthesis purification

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

The Influence of Some Key Parameters on Fatigue Life of Common Metallic Components

引用

Journal of central south university 2000年第3期12卷 159-161页

作者： LIU Yi lun (college of Mechanical and Electrical Engineering, central south university, changsha 410083, china) 1. college of Mechanical and Electrical Engineering Central South University 410083 Changsha China

The effect of key parameters on fatigue life of common metallic components, e.g. steel, aluminium alloy, has been analysed quantitatively. The influential coverage and degree of these parameters have been investigated systematically, some phenomena which can′t be discovered with qualitative analysis method have been revealed, a series of valuable conclusions has been obtained, which would be very beneficial to fatigue resistant design and improvement of anti fatigue ability of metallic components.

关键词： metallic material component fatigue life key parameter effect

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

Practical stabilization of receding-horizon control

引用

Journal of central south university of Technology 2001年第4期8卷 268-271页

作者： LIU Bi yu,GUI Wei hua,MU Min (college of Information science and Engineering, central south university, changsha 410083, china) 1. college of Information science and Engineering Central South University 410083 Changsha China

The purpose of this work is to propose a scheme to stabilize the predictive control systems in the practical stability sense. In the paper, the authors dealt with a general discrete predictive control system x j+1|t =f(x j|t , u j|t ) by using the Lyapunov direct method combining with receding horizon control technique, and presented a new condition to guarantee the practical stabilization of the systems. With the proposed results, one can design the optimal controllers easily to practically stabilize the predictive control systems.

关键词： receding-horizon control practical stability Lyapunov function nonlinear system optimization

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

Anycast service model and its QoS routing algorithm

引用

Journal of central south university 2001年第2期8卷 135-139页

作者： WANG Jian xin, CHEN Song qiao, CHEN Jian er (college of Information science and Engineering, central south university, changsha 410083, china) 1. college of Information science and Engineering Central South University 410083 Changsha China

In the Internet, a group of replicated servers is commonly used in order to improve the scalability of network service. Anycast service is a new network service that can improve network load distribution and simplify certain applications. In this paper, the authors described a simple anycast service model in the Internet without significant affecting the routing and protocol processing infrastructure that was already in place, and proposed an anycast QoS routing algorithm for this model. The algorithm used randomized method to balance network load and improve its performance. Several new techniques are proposed in the algorithm, first, theminimum hops for each node are used in the algorithm, which are used as metric for computing the probability of possible out links. The metric is pre computed for each node in the network, which can simplify the network complexity and provide the routing process with useful information. Second, randomness is used at the link level and depends dynamically on the routing configuration. This provides great flexibility for the routing process, prevents the routing process from overusing certain fixed routing paths, and adequately balances the delay of the routing path. the authors assess the quality of QoS algorithm in terms of the acceptance ratio on anycast QoS requests, and the simulation results on a variety of network topologies and on various parameters show that the algorithm has good performances and can balance network load effectively.

关键词： QoS anycast service network routing randomized algorithm

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

Hyers-Ulam-Rassias stability of approximate isometries on restricted domains

引用

Journal of central south university of Technology 2002年第4期9卷 289-292页

作者： XIANG Shu huang college of Mathematical science and Computational Technology, central south university, changsha 410083, china 1. college of Mathematical science and Computational Technology Central South University 410083 Changsha China

Let X and Y be real Banach spaces. The stability of Hyers Ulam Rassias approximate isometries on restricted domains S (unbounded or bounded) for into mapping f: S→Y satisfying ‖ f(x)-f(y)‖-‖x-y‖≤ε(x,y) for all x,y∈S is studied in case that the target space Y is uniformly convex Banach space of the modulus of convexity of power type q ≥2 or Y is the L q(Ω,,μ) (1

关键词： Hyers-Ulam-Rassias stability isometry uniformly convex space Hilbert space

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：