检索结果-南通市图书馆

Design and Implementation of Visual Simulation System for Shipborne Crane control

在线全文

学校读者我要写书评

暂无评论

Design and Implementation of Visual Simulation System for Sh...

Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2.molecule

2.09中国控制与决策会议

作者： Peng Li~(1,2.,Cungang Wang~2.1.harbin Institute of Technology,harbin {2.,china 2.college of Automation,harbin engineering University,harbin {2.,china

＜正＞The shipborne crane studied in this paper is a complex system made up of the foldaway and controlled arms, which has the important function for ships working on sea.A visual simulation system for this shipborne crane with virtual reality is designed and realized by OpenGL on VC++（Visual C++） *** present system can realize the visual simulation for trajectory-planning and joint control along track at the certain *** main characteristics of structure and function of the visual simulation system are *** software scheme is brought ***’s essential for virtual simulation software to apply in the studies of kinematics and dynamics simulation for this kind of shipborne *** results of visual simulation show that this system is workable and *** is an important simulation environment for the study of the crane’s operation on the sea and offers a very effective,economical means or approach for the research and development of other similar systems.

关键词： Shipborne Crane Visual Simulation System OpenGL Design and Implementation

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 385-398页

作者： REN Weiyi1,2. SUN Weiguo1, HOU Shilin3 & FENG Hao4 1. Institute of Physics, college of chemical {2., Sichuan University, Chengdu 610065, china 2. Institute of Theoretical Physics, Xihua Normal University, Nanchong 637002. china 3. Department of Physics, china Oceanography University, Qingdao 2.6003, china 4. college of Physics, Sichuan University, Chengdu 610065, china 1. Institute of Physics College of Chemical Engineering Sichuan University 610065 Chengdu China 2. Institute of Theoretical Physics Xihua Normal University 637002 Nanchong China 3. Department of Physics China Oceanography University 266003 Qingdao China 4. college of Physics Sichuan University 610065 Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2.molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

Adsorption and Desorption of Thiophene Vapor on NaY/NiY Zeolites

在线全文

学校读者我要写书评

暂无评论

china Petroleum Processing & Petrochemical Technology 2010年第2期12卷 45-50页

作者： Liu Daosheng~(1,2. Song Lijuan~2.Ju Xiufang~2.Duan Linhai~2.Sun Zhaolin~(1,2. (1.college of Chemistry & chemical {2.,china University of Petroleum(East china),Dongying 2.7061 2.Liaoning Key Laboratory of Petrochemical {2.,Liaoning Shihua University) china Univ Petr E china Coll Chem & Chem Engn Dongying 257061 Peoples R China Liaoning Shihua Univ Liaoning Key Lab Petrochem Engn Liaoning Peoples R China

FT-IR spectrometry, TPD and adsorption isotherms of thiophene on NaY/NiY zeolites were carried out and the diffusion coefficient was obtained by means of its real-time dynamic curves. The loading of thiophene adsorbed on the NaY zeolite decreased with an increasing temperature, which was ascribed to the patterns of physical adsorption. Both physical and chemical adsorption phenomena were detected on the NiY zeolite, with the 0 complexation and S-M interaction existing during the chemical adsorption. The loading of thiophene adsorbed on the NiY zeolite at 302.K and 335 K was equal, but it decreased at 373 K. The diffusion coefficient of thiophene on the NaY zeolite decreased when the loading increased to more than 0.02.mmol/g, and on the contrary that of thiophene on the NiY zeolite did not change obviously with the loading adsorbed.

关键词： adsorption diffusion coefficient temperature-programmed desorption (TPD)

Nanocrystalline TiO2.thin film electrodes prepared by common pressure hydrothermal method at low temperature

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2005年第14期 43-46页

作者： LI Chengyu1,2. LIN Yuan1, LI Xueping1, WANG Zhengping2. MA Yutao1, ZHOU Xiaowen1, FENG Shujing1 & XIAO Xurui1 1. Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, china 2. chemical {2. of harbin engineering University, harbin 150001, china

Nanocrystalline TiO2.thin film electrodes have been prepared from mixed pastes of tetrabutyl titanate and nanocrystalline TiO2.particles by common pressure hydro- thermal method at low temperature. The tetrabutyl titanate was hydrolyzed and crystallized into anatase TiO2.to inter- connect nanocrystalline TiO2.particles and adhere them to conductive substrates, obtaining highly porous and me- chanically stable TiO2.nanocrystalline film. The conversion efficiencies of the dye-sensitized solar cells based on prepared electrodes on conductive glass substrates and flexible sub- strates were 4.8% and 1.9% under illumination of 100 mW/cm2. respectively.

关键词： nanocrystalline TiO2.thin film electrode tetrabutyl titan- ate common pressure hydrothermal method low-temperature preparation dye-sensitized solar cell.

Preparation of well-defined polystyrene/silica hybrid nanoparticles by ATRP

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Chemistry 2008年第1期51卷 51-57页

作者： OU BaoLi1,2.LI DuXin2.1 college of Chemistry and chemical {2.,Hunan University of Science and Technology,Xiangtan 4112.1, china 2.State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083, china 1. college of Chemistry and chemical {2. Hunan University of Science and Technology Xiangtan 411201 China 2. State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China

Immobilization of the atom transfer radical polymerization (ATRP) macroinitiators at the silica nanoparticle surfaces was achieved through surface modification with excess toluene-2.4-diisocynate (TDI), after which the residual isocyanate groups were converted into ATRP macroinitiators. Structurally well-defined polystyrene chains were grown from the nanoparticle surfaces to yield individual particles composed of a silica core and a well-defined, densely grafted outer polystyrene by ATRP, which was initiated by the as-synthesized silica-based macroinitiator. FTIR, NMR and gel permeation chro-matography (GPC) were used to characterize the polystyrene/silica hybrid particles.

关键词： silica nanoparticles surface modification atom transfer radical polymerization polystyrene hybrid particle

An Investigation of Laser Assisted Machining of Al_2._3 Particle Reinforced Aluminum Matrix Composite

在线全文

学校读者我要写书评

暂无评论

厦门大学学报（自然科学版） 2002年第S1期41卷 7-8页

作者： WANG Yang, YANG Li-jun, WANG Na-jun (Department of Mechanical engineering, harbin Institute of Technology,{2., china)

The Al 2. 3 particles reinforced aluminum matrix composite (Al 2. 3p/Al) are more and more widely used for their excellent physical and chemical properties. However, their poor machinability leads to severe tool wear and bad machined surface. In this paper laser assisted machining is adopted in machining Al 2. 3p/Al composite and good result was obtained. The result of experiment shows in machining Al 2. 3p/Al composites the cutting force is reduced in 30%～50%, the tool wear is reduced in 2.%～30% and machined surface quality is improved in laser assisted machining as compared with conventional cutting. The physical model of the cutting process is set up and explains the reason why the cutting forced are reduced. The state of the particles is the main influence of the change. When the material of cutting zone is heating by laser, the aluminum matrix becomes softer and easier in plastic deformation, which leads to the reduction of the pushing force from the tool to the machined surface. The soften aluminum matrix is more easy to be squeezed out from the machined surface, and it leads the concentration of the Al 2. 3 particles in the surface layer of machined surface. The softening effect of laser heating on aluminum matrix reduces the pushing forces of the Al 2. 3 particles on the clearance face of cutting tool, which is just the reason for the severe cutting tool wear in conventional machining of Al 2. 3p/Al composite. Because the Al 2. 3 particles were pushed in during the cutting process, the particles increased in the surface layer. Because of the difference in thermal conductivity and thermal expansion between the Al-matrix and Al 2. 3 particle, residual stress is changed in the matrix after machining due to the extrusion of the tool, deformation of the matrix and displacement of the Al 2. 3 particle in the matrix. Temperature gradient comes into the cutting zone and the work-piece surface layer, it will lead to the increase of thermal stress and misfit dislocati

关键词： cutting composite materials laser-assisted machining

基因启动子甲基化对转录因子结合的抑制作用分析方法

在线全文

学校读者我要写书评

暂无评论

生物化学与生物物理进展 2011年第2期38卷 177-184页

作者：冯伟兴王科俊贺波李霞哈尔滨医科大学生物信息科学与技术学院哈尔滨150081 哈尔滨工程大学自动化学院哈尔滨150001

基因启动子甲基化对转录因子结合的抑制作用是一种有效的基因转录调控机制.尽管基因启动子甲基化水平已经可以通过实验测量,但仍未有有效的方法利用这些数据定量分析甲基化对转录因子结合的影响.设计一个通用模型来描述基因启动子甲基... 详细信息

基因启动子甲基化对转录因子结合的抑制作用是一种有效的基因转录调控机制.尽管基因启动子甲基化水平已经可以通过实验测量,但仍未有有效的方法利用这些数据定量分析甲基化对转录因子结合的影响.设计一个通用模型来描述基因启动子甲基化对转录因子结合的抑制作用.在特定细胞环境下,通过基因表达与转录因子在基因启动子上结合值之间的相关性分析,实现模型参数求取,并基于该模型进行甲基化对转录因子结合的抑制作用分析.神经细胞生物实验数据测试证明了该方法的有效性.

关键词：基因启动子转录因子 DNA甲基化分析方法

Preparation of polystyrene/silica nanocomposites by radical copolymerization of styrene with silica macromonomer

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2007年第3期50卷 385-391页

作者： OU BaoLi1,2.& LI DuXin2.1 college of Chemistry and chemical {2., Hunan University of Science and Technology, Xiangtan 4112.1, china 2.State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, china 1. college of Chemistry and chemical {2. Hunan University of Science and Technology Xiangtan 411201 China 2. State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China

A two-stage process has been developed to generate the silica-based macromonomer through surface-modification of silica with polymerizable vinyl groups. The silica surfaces were treated with excess 2.4-toluene diisocynate (TDI), after which the residual isocyanate groups were converted into polymerizable vinyl groups by reaction with hydroxypropylacrylate (HPA). Thus, polystyrene/silica nanocomposites were prepared by conventional radical copolymerization of styrene with silica macromonomer. The main effecting factors, such as ratios of styrene to the macromonomer, together with polymerization time on the copolymerization were studied in detail. FTIR, DSC and TGA were utilized to characterize the nanocomposites. Experimental results revealed that the silica nanoparticles act as cross-linking points in the polystytene/silica nanocomposites, and the glass transition temperatures of the nanocomposites are higher than that of the corresponding pure polystyrene. The glass transition temperatures of nanocomposites increased with the increasing of silica contents, which were further ascertained by DSC.

关键词： silica nanoparticles surface modification styrene radical copolymerization nanocomposites

MATHEMATICAL MODEL OF MILLING TEMPERATURE AND TEMPERATURE FIELD ANALYSIS FOR THREE-DIMEN-SIONAL COMPLEX GROOVE MILLING INSERT

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical engineering 2003年第4期16卷 340-343页

作者： Li ZhenjiaDong LihuaTan GuangyuGuo QiangCheng Yaonancollege of Mechanical engineering,{2. University of Scienceand Technology,{2. 150080, china college of Mechanical engineering Harbin University of Science and Technology Harbin 150080 China

The mathematical model on the temperature of the waved-edge is constructedaccording to Jaeger's theory of moving solid and based on the used temperature model of the flatinsert. It is possible to forecast the milling temperature through programming. The comparableexperiments have been done between the two new three-dimension groove inserts (waved-edge insert,great edge insert) and flat fake insert. The theoretic forecast is in good agreement with theexperimental result. According to the cutting conditions, the boundary condition of finite elementanalysis on cutting temperature field is established, and the three-dimensional temperature fieldsof inserts with grooves are analyzed by FEM, so as to offer a reference basis for the design andoptimization of insert grooves.

关键词： Three-dimensional groove milling insert Cutting temperature mathematicalmodel Temperature field Finite element analysis