检索结果-南通市图书馆

Study on the two and three-parameter working stability regions of 3.-TZP suspension

Science china(Technological sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1, 2, ZHANG Xinni3. CHEN Sha’ou3.& QI Ping3.1. Department of Chemistry, Qingdao university, Qingdao 266071, china 2. Department of Chemistry, Tsinghua university, Beijing 100084, china 3. Department of Physics, Qingdao university, Qingdao 266071, china 1. Department of Chemistry Qingdao University Qingdao 266071 China 2. Department of Chemistry Tsinghua University Beijing 100084 China 3. Department of Physics Qingdao University Qingdao 266071 China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3.-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3.-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3.-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3.-TZP, suspension, stability, DLVO theory, interparticle potential energy.

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 steady-state solution of dendritic growth from the undercooled binary alloy melt with the far field flow

引用

Science china(Technological sciences) 2009年第8期52卷 2280-2287页

作者： CHEN MingWen1,2, WANG ZiDong2 & XU JianJun2,3.4 1 School of Applied sciences, university of Science and Technology Beijing, Beijing 100083. china 2 School of Materials Science and Engineering, university of Science and Technology Beijing, Beijing 100083. china 3.School of mathematical sciences, Nankai university, Tianjin 3.0071, china 4 Department of Mathematics and Statistics, McGill university, Montreal H3. 2K6, Canada School of Applied sciences University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of mathematical sciences Nankai University Tianjin 300071 China Department of Mathematics and Statistics McGill University Montreal H3A 2K6 Canada

The steady-state dendritic growth from the undercooled binary alloy melt with the far field flow is considered. By neglecting the interface energy, interface kinetics and buoyancy effects in the system, we obtaine the steady-state solution for the case of the large Schmidt number, in terms of the multiple variable expansion method. The changes of the temperature and concentration fields, the morphology of the interface, the normalization parameter and the Peclet number of the system induced by uniform external flow are derived. The results show that, compared with the system of dendritic growth from undercooled pure melt, the convective flow in the system of growth from undercooled binary alloy has stronger effects on the morphology of the interface. Nevertheless, the shape of the interface still remains nearly a paraboloid.

关键词： binary alloy melt convection dendritic growth interfaces steady-state solution multiple variable expansion method

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

Geochemical simulation of the formation of brine and salt minerals based on Pitzer model in Caka Salt Lake

引用

Science china Earth sciences 2004年第8期47卷 720-726页

作者： LIU Xingqi1, CAI Keqin2 & YU Shengsong3.1. Nanjing Institute of Geography and Limnology, Chinese Academy of sciences, Nanjing 210008, china 2. china {3. of Geosciences, Beijing 100083. china 3. Institute of Salt Lakes, Chinese Academy of sciences, Xining 810008, china 1. Nanjing Institute of Geography and Limnology Chinese Academy of Sciences 210008 Nanjing China 2. china university of Geosciences 100083 Beijing China 3. Institute of Salt Lakes Chinese Academy of Sciences 810008 Xining China

The geochemical simulation of the formation of brine and salt minerals based on Pitzer model was made in Caka Salt Lake. The evolution of the mixed surface-water and the mineral sequences were calculated and compared with the hydrochemical compositions of the brine and the salt minerals of the deposit in Caka Salt Lake. The results show that the formation temperature of the lake is between 0°C and 5°C, which is well identical with other studies. The mixing of salt-karst water with the surface waters, neglected by the former researchers, is very important to the formation of the lake, indicating that the initial waters resulting in the formation of the lake are multi-source. It is the first time to use Pitzer model in china for making geochemical simulation of the formation and evolution of inland salt lake and satisfactory results have been achieved.

关键词： Pitzer model,Caka Salt Lake,geochemical simulation,salt-karst water.

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

MDV-1 VP22 conjugated VP2 enhancing immune response against infectious bursal disease virus by DNA vaccination in mice

引用

Science china(Life sciences) 2008年第11期51卷 981-986页

作者： CHEN HongJun1,2, ZHANG ChenFei1, SONG CuiPing1,2, DENG XuFang1 & QIN AiJian1 1 Key lab of Jiangsu Preventive Veterinary Medicine, yangzhou university, yangzhou 225009, china 2 Shanghai Veterinary Research Institute, Chinese Academy of Agricultural {3., Shanghai 20023., china Key lab of Jiangsu Preventive Veterinary Medicine Yangzhou University Yangzhou 225009 China Shanghai Veterinary Research Institute Chinese Academy of Agricultural Sciences Shanghai 200232 China

VP22 of Marek’s disease virus serotype 1 (MDV-1) could function in protein transduction. In this study, an infectious bursal disease virus VP2 gene was fused to the carboxyl termini of VP22. It showed that the fusion protein did not spread into the bystander cells from the cells transfected with pVP22-VP2, as the VP22 alone could. The VP22 proteins were found to be translocated into all the nuclei in the neighboring COS-1 cells, as analyzed by a fluorescence assay. Although mice were immunized with the recombinant DNAs mixed with polyethylenimine (PEI) at a dose of 1:2, it failed to enhance the antibody response against IBDV VP2, as measured by the indirect ELISA assay, yet the cell mediated immune response was significantly increased. The ratio of CD8+/CD4+ T cells was significantly increased in the immunized group with the fusion genes, compared with the group immunized with VP2 (P22 indeed enhances the cell-mediated response in the fused VP2 in a mice model system, possibly due to the fact that the IBDV VP2 could be carried into the surrounding cells at a limited level under pressure from MDV VP22.

关键词： Marek’s disease virus serotype 1 VP22 infectious bursal disease virus VP2 DNA immunization

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

基于交通预测信息的电动汽车充电路径规划

引用

北京工业大学学报 2024年第8期50卷 974-984页

作者：师泽宇陈阳舟安树科北京工业大学交通工程北京市重点实验室北京100124 北京工业大学信息学部人工智能与自动化学院北京100124 云南警官学院治安管理学院昆明650223

针对电动汽车充电路径规划问题,以行程时间为优化目标,以荷电状态作为硬性约束,基于预测交通状态标定的动态异构交通网及车辆动力学模型,构建最优控制问题。为了在线求解,基于模型预测控制和强化学习方法,构建混合学习优化算法(hybrid l... 详细信息

针对电动汽车充电路径规划问题,以行程时间为优化目标,以荷电状态作为硬性约束,基于预测交通状态标定的动态异构交通网及车辆动力学模型,构建最优控制问题。为了在线求解,基于模型预测控制和强化学习方法,构建混合学习优化算法(hybrid learning optimization algorithm, HLOA),依托竞争深度Q网络(Dueling deep Q-networks, Dueling DQN),设计离线、在线模块,来实现参数的混合多步训练,并结合预测交通状态、网络拓扑及车辆动力学模型,输出在线行驶策略。采用某市局部路网构建交通仿真实验,分析预测交通信息的价值、HLOA算法可行性及结构必要性。结果表明,预测信息存在价值,HLOA在线结果可拟合最优策略且较其他算法精度提高3..65%。该研究可协助电动汽车用户导航,为自动驾驶电动汽车提供技术支撑。

关键词：智能交通系统车辆路径规划电动汽车充电路径规划强化学习在线寻优混合学习优化算法

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

Dimensions of a class of high-dimensional homogeneous Moran sets and Moran classes

引用

Progress in Natural Science:Materials International 2002年第9期12卷 17-22页

作者： YAN Ping(Department of mathematical sciences, Tsinghua university, Beijing 100084,{3.) Tsing Hua Univ Dept Math Sci Beijing 100084 Peoples R China

A class of high-dimensional homogeneous Moran sets and Moran classes are introduced and some dimensional properties are studied. The Hausdorff dimension, modified lower box-counting dimension, lower and upper box-counting dimension, and packing dimension of high-dimensional homogeneous and partial homogeneous Cantor sets are determined. Moreover, a kind of fractal E is obtained, which is not regular but with the property Dimw(Ed) = dDimw(E), where w denotes any of the dimensions mentioned above.

关键词： Moran set Moran class homogeneous Cantor set partial homogeneous Cantor set dimension.

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

EXACT NONREFLECTING BOUNDARY CONDITIONS FOR AN ACOUSTIC PROBLEM IN THREE DIMENSIONS

引用

Journal of Computational Mathematics 2003年第1期21卷 15-24页

作者： Houde Han Chunxiong Zheng (Department of mathematical sciences, Tsinghua university, Beijing 100084,{3.) Department of mathematical sciences Tsinghua University 北京 100084

In this paper, nonreflecting artificial boundary conditions are considered for an acoustic problem in three dimensions. With the technique of Fourier decomposition under the orthogonal basis of spherical harmonics, three kinds of equivalent exact artificial boundary conditions are obtained on a spherical artificial boundary. A numerical test is presented to show the performance of the method.

关键词： Exterior problem Nonreflecting artificial boundary condition Acoustic equa-tion Three-dimensions.

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

Γ-CONVERGENCE OF INTEGRAL FUNCTIONALS DEPENDING ON VECTOR-VALUED FUNCTIONS OVER PARABOLIC DOMAINS

引用

Chinese Annals of Mathematics,Series B 2000年第2期21卷 249-258页

作者： JIAN HUAIYU(Department of mathematical sciences, Tsinghua university, Beijing 100084,{3..) Department of mathematical sciences Tsinghua University Beijing 100084 China

This paper studies Γ-convergence for a sequence of parabolic functionals, where the integrand f is nonconvex, and periodic on the first variable. The author obtains the representation formula of the Γ-limit. The results in this paper support a conclusion which relates Γ-convergence of parabolic functionals to the associated gradiend flows and confirms one of De Giorgi’s conjectures partially.

关键词： Γ-convergence Parabolic-minima Nonconvex functionals Parabolic equations

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 airspace configuration method based on a weighted graph model

引用

Chinese Journal of Aeronautics 2014年第4期27卷 903-912页

作者： Chen yangzhou Zhang Defu School of Electronic Information and Control Engineering Beijing University of Technology

This paper proposes a new method for dynamic airspace configuration based on a weighted graph model. The method begins with the construction of an undirected graph for the given airspace, where the vertices represent those key points such as airports, waypoints, and the edges represent those air routes. Those vertices are used as the sites of Voronoi diagram, which divides the airspace into units called as cells. Then, aircraft counts of both each cell and of each air-route are computed. Thus, by assigning both the vertices and the edges with those aircraft counts, a weighted graph model comes into being. Accordingly the airspace configuration problem is described as a weighted graph partitioning problem. Then, the problem is solved by a graph partitioning algorithm, which is a mixture of general weighted graph cuts algorithm, an optimal dynamic load balancing algorithm and a heuristic algorithm. After the cuts algorithm partitions the model into sub-graphs, the load balancing algorithm together with the heuristic algorithm transfers aircraft counts to balance workload among sub-graphs. Lastly, airspace configuration is completed by determining the sector boundaries. The simulation result shows that the designed sectors satisfy not only workload balancing condition, but also the constraints such as convexity, connectivity, as well as minimum distance constraint.

关键词： Airspace sector Air traffic control Dynamic airspace configuration Graph partitioning Graph theory Weighted graph Workload

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

Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

引用

Science china Earth sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2, ZHAO Zhidan1,2, ZHANG Hongfei3. ZHANG Benren3.& CHEN Yuelong2 1. State Key Laboratory of Geological Processes and Mineral Resources, china university of Geosciences, Beijing 100083. china 2. School of Earth Science and Mineral Resources, china university of Geosciences, Beijing 100083. china 3. Faculty of Earth sciences, china university of Geosciences, Wuhan 43.074, china 1. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China 2. School of Earth Science and Mineral Resources China University of Geosciences Beijing 100083 China 3. Faculty of Earth sciences China University of Geosciences Wuhan 430074 China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.27). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2Nb-Zr/4-Y and Ti/100-Zr-YX3.tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143.Nd/^(144)Nd (0.512955-0.512978). Pb isotopes are in the rangeof ^(206)Pb/^(204)Pb (18.054-20.562), ^(207)Pb/^(204)Pb (15.53.-15.743. and ^(208)Pb/^(204)Pb(3..068-3..53.). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.

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：