检索结果-南通市图书馆

Stability of core-annular flow of power-law fluids in the presence of interfacial surfactant

Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 933-943页

作者： SUN XueWei,PENG Jie & ZHU KeQin department of Engineering Mechanics,tsinghua {2.,beijing 100084,china 1. department of Engineering Mechanics Tsinghua University Beijing 100084 China

The shear-thinning influence on the core-annular flow stability of two immiscible power-law fluids is considered by making a linear stability *** flow is driven by an axial pressure gradient in a straight pipe with the interface between the two fluids occupied by an insoluble *** the basic flow for this core-annular arrangement,the analytical solution is obtained with respect to the power-law fluid *** linearized equations for the evolution of infinitesimal disturbances are derived and the stability problem is formulated as a generalized matrix eigenvalue problem,which is solved by using the software package Matlab based on the QZ *** shear-thinning property is found to have marked influence on the power-law fluid core-annular flow stability,which is reflected in various ***,the capillary instability is magnified by the shear-thinning property,which may lead to an essential difference between power-law and Newtonian fluid *** when the interface is close to the pipe wall,the power-law fluid flow may be unstable while the Newtonian fluid flow is ***,under disturbances to the interface a velocity discontinuity at the interface appears which is destabilizing to the *** magnitude of this velocity discontinuity is affected by the power-law index and the flow stability is influenced ***,the shear-thinning property may induce new stability modes which do not appear in the Newtonian fluid *** flow stability shows much dependence on the interface location,the role of which was neglected in most previous *** shear-thinning fluid flow is more unstable to long wave disturbances when the interface is close to the pipe wall,while the Newtonian fluid flow is more unstable when the interface is close to the pipe *** this trend is changed by the addition of interfacial surfactant,for which the power-law fluid flow is more stable no matter where the interface is loca

关键词： core-annular flow power-law fluid interfacial surfactant linear stability analysis

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

QUASI-STATIONARY DISTRIBUTIONS FOR THE RADIAL ORNSTEIN-UHLENBECK PROCESSES

引用

Acta Mathematica Scientia 2008年第3期28卷 513-522页

作者：叶俊 department of Mathematical Sciences Tsinghua University

The purpose of this article is to obtain the quasi-stationary distributions of the δ（δ 〈 2.-dimensional radial Ornstein-Uhlenbeck process with parameter -λ by using the methods of Martinez and San Martin （2.01）. It is described that the law of this process conditioned on first hitting 0 is just the probability measure induced by a （4 - δ）- dimensional radial Ornstein-Uhlenbeck process with parameter -λ. Moreover, it is shown that the law of the conditioned process associated with the left eigenfunction of the process conditioned on first hitting 0 is induced by a one-parameter diffusion.

关键词： Radial Ornstein-Uhlenbeck process quasi-stationary distribution quasiinvariant

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

Reduced analysis and confirmatory research on co-adaptability theoretical solution to conflicting events in construction engineering projects

引用

Science china(Technological Sciences) 2010年第2期53卷 480-485页

作者： HOU XueLiang1 , LU Mei2.& WANG Kai3 1 School of Business Administration, North china Electric Power university, {2. 102.06, china 2.department of Construction Management, tsinghua university, beijing 100084, china 3 College of Management, {2. Jiaotong university, beijing 100084, china 1. School of Business Administration North China Electric Power University Beijing 102206 China2. Department of Construction Management Tsinghua University Beijing 100084 China3. College of Management Beijing Jiaotong University Beijing 100084 China

The co-adaptability theoretical solution to conflicting events in construction engineering projects has three problems. First, the transformation of constraint conditions of theoretical solution is very difficult in practical engineering applications; second, some coefficients are difficult to be determined; third, there are overfull circular arithmetic operations involved in it. To resolve these problems, a new method to reduce the theoretical solution complications is proposed. By analyzing the operating mechanism of theoretical solution model, redundancies in the theoretical solution can be eliminated, and the ISM mapping with the co-adaptability solution can be set up. Based on this approach, a procedure to solve practical conflicting events in construction projects is established by replacing characteristic variables with mathematic variables. The research results show that the procedure can replace the co-adaptability theoretical solution effectively and solve practical conflicting events in construction projects.

关键词： construction project conflict theoretical solution reduced analysis ISM confirmatory research

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

A Novel CAPP System Based on SML for Variant Design of Process Planning

引用

武汉理工大学学报 2006年第S3期28卷 820-823页

作者： ZHAO Haibin~1 WANG Junying~1 ZHANG Min~2.(1.department of precision {2. & mechanology,tsinghua university,beijing 100084,china, 2.department of Mechanical Equipment & Control Engineering,beijing university of Science and Technology,Bejing 100083,china) department of precision {2. & mechanology Tsinghua UniversityBeijing 100084China department of Mechanical Equipment & Control Engineering Beijing University of Science and TechnologyBejing 100083 China

The production model of“multi-specification and low-quantity”is becoming the main trend of manufacturing *** a key activity in the manufacturing chain,traditional computer aided process planning(CAPP)system fails to adapt to the production model of ***,a novel method for variant design of process planning was proposed to develop CAPP system based on Tabular Layouts of Article Characteristics(Sach-Merk Leisten in German and SML for short). With the support of standard database of master process planning documents which are developed by parameterization technique, and instance process planning for special product(instance product)can be generated automatically by the sub-system of variant de- sign of process ***,a CAPP system was developed for process design of rotor of steam turbine to validate the feasibil- ity and applicability of the method.

关键词： CAPP variant design SML master process planning documents(DocMPP) parameterization

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

A Remark on the Symplectic Blow-up in Dimension 4

引用

Acta Mathematica Sinica,English Series 1996年第4期12卷 379-384页

作者： Ma Renyi department of Applied Mathematics tsinghua university {2., 100084 china department of Applied Mathematics Tsinghua University Beijing China

In this note, we prove that the symplectic blow-up or blow-down in the dimension 4 is rigid, i.e. the symplectic area of the divisor does not exceed the symplectic radius of the neighbourhood on which we do the blow-u... 详细信息

关键词： J-Holomorphic disc Contact manifold Symplectic blow-up

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

Centralizers and Iterate Radicals of Morse-Smale Diffeomorphisms of the Circle

引用

Acta Mathematica Sinica,English Series 1995年第1期11卷 1-11页

作者： Zhang Meirong department of Applied Mathematics tsinghua university {2.,100084 china department of Applied Mathematics Tsinghua University Beijing People's Republic of China

In this paper,we will use the embedding flows in[1],[2.to give a complete descrip- tion of the smooth centralizers and iterate radicals of all C^r(r≥2.Morse-Smale diffeomorphisms of the circle S^*** a result,we prove... 详细信息

关键词： Centralizers and Iterate Radicals of Morse-Smale Diffeomorphisms of the Circle TDFs

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

Gas kinetic algorithm for flows in Poiseuille-like microchannels using Boltzmann model equation

引用

Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 496-512页

作者： LI Zhihui1,2. ZHANG Hanxin1 & FU Song2.⒈ National Laboratory for CFD, Hypervelocity Aerodynamics Institute,china Aerodynamics Research and Development Center,Mianyang 62.000,china 2.{2. of Engineering Mechanics,tsinghua university,beijing 100084,china 1. National Laboratory for CFD Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development Center 621000 Mianyang China 2. department of Engineering Mechanics Tsinghua University 100084 Beijing China

The gas-kinetic unified algorithm using Boltzmann model equation have been extended and developed to solve the micro-scale gas flows in Poiseuille-like micro-channels from Micro-Electro-Mechanical Systems (MEMS). The numerical modeling of the gas kinetic boundary conditions suitable for micro-scale gas flows is presented. To test the present method, the classical Couette flows with various Knudsen numbers, the gas flows from short microchannels like plane Poiseuille and the pressure-driven gas flows in two-dimensional short microchannels have been simulated and compared with the approximate solutions of the Boltzmann equation, the related DSMC results, the modified N-S solutions with slip-flow boundary theory, the gas-kinetic BGK-Burnett solutions and the experimental data. The comparisons show that the present gas-kinetic numerical algorithm using the mesoscopic Boltzmann simplified velocity distribution function equation can effectively simulate and reveal the gas flows in microchannels. The numerical experience indicates that this method may be a powerful tool in the numerical simulation of micro-scale gas flows from MEMS.

关键词： Boltzmann model equation, discrete velocity ordinate method, finite-difference scheme, Couette flow, Poiseuille flow, gas flow in short-microchannel.

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

DYNAMIC AND KINEMATIC WAVE MODELSFOR 1-D RILL FLOW: A COMPARISON

引用

International Journal of Sediment Research 1999年第2期14卷 95-105页

作者： SHAO Xuejun (department of Hydraulic Engineering, tsinghua university,{2., china)

Overland flows on hillslopes due to rainfall excess are numerically simulated with a simplified strip microtopography which has one single straight rill, and comparisons are made between predictions of a dynamic wave model (DWM) and a kinematic wave model (KWM). Overland flow on the strip is treated as one-dimensional and interrill flow is not simulated. The DWM is based on the Saint-Venant equation, and the KWM is derived using the Chezy formula. A numerical scheme is developed which solves the non-linear DWM equations in a similar way to that of solving the KWM equations, *** the basis of the method of characteristics. This scheme greatly reduces the complexity of the solution procedure and therefore allows the use of DWM in process-based catchment models involving a large number of topographical elements, i.e., hillslopes. Simulation result shows that. in terms of the predicted flow velocity V and depth h, the *** model is an accurate approximation to the dynamic one for broad sheet overland flows resulted from normal rainfall excess rates (1-3 mm/min). However. for small rill width, e.g. B2.cm. or if the rainfal excess rate is extremely large (e.g.. 2. mm/min). differences of V and h between the two models will be significant. In general, the KWM tends to underestimate rill flow depth but overestimate its velocity, especially for small rill width. though it does give the same steady discharge per unit width, q =V h, as that predicted by DWM for steady rainfall excess rate. At the rising stage of the hydrograph, KWM predicts higher unit width discharge q, which leads to overestimation of rill detachment as a stream power function method is used.

关键词： Overland flow Rill flow Kinematic wave model Method of characteristics

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

Local Gromov-Witten invariants of canonical line bundles of toric surfaces

引用

Science china Mathematics 2010年第6期53卷 1571-1582页

作者： YANG Fei & ZHOU Jian department of Mathematical Sciences,tsinghua {2.,beijing 100084,china 1. department of Mathematical Sciences Tsinghua University Beijing 100084 China

We define and compute by localizating the local equivariant Gromov-Witten invariants of the canonical line bundles of toric surfaces,not necessarily Fano.

关键词： local Gromov-Witten invariants localization partition function geometric engineering

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

Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

引用

Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 706-715页

作者： ZHANG Jingfu1, XIE Jingyi2. WANG Chuan1, DENG Zhiwei3, LU Zhiheng4, & LONG Guilu1,5 1. Key Laboratory For Quantum Information and Measurements of MOE, department of Physics, tsinghua university,{2.,china 2. department of Materials Science and Engineering, beijing Normal university, beijing 100875, china 3. Testing and Analytical Center, beijing Normal university, beijing 100875,china 4. department of Physics, beijing Normal university, beijing 100875, china 5. Key Laboratory For atomic and Molecular Nanosciences, tsinghua university,{2.,china 1. Key Laboratory For Quantum Information and Measurements of MOE Department of Physics Tsinghua University 100084 Beijing China 2. department of Materials science and Engineering Beijing Normal University 100875 Beijing China 3. Testing and Analytical Center Beijing Normal University 100875 Beijing China 4. department of Physics Beijing Normal University 100875 Beijing China 5. Key Laboratory For Atomic and Molecular Nanosciences Tsinghua University 100084 Beijing China

A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2.+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

关键词： quantum dense coding, multiple round, nuclear magnetic resorance

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：