检索结果-南通市图书馆

Research progress in gecko locomotion and biomimetic gecko-robots

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第1期17卷 1-5页

作者： DAI Zhendong and SUN Jiurong ( institute of Bio-inspired Structure and Surface Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 2.0016, china College of Life Sciences, Peking University, {2. 100871, china) institute of Bio-inspired Structure and Surface Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Life Sciences Peking University Beijing 100871 China

Geckos are known for their excellent ability to climb walls and run on ceilings. Previous studies of the gecko's locomotive and adhesive mechanisms, its neuro-sensory and neuro-modulatory systems, its fabrication of artificial setae array, and other related developments, have inspired further research on gecko-based and gecko-like robots. Key research findings in this area are reviewed in the present paper.

关键词： gecko locomotion biomimetic modulation gecko-like robot.

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国城市化模式的选择问题研究

学习与探索 2003年第1期 90-94页

作者：王树春王玉婧刘学敏天津商学院天津300400 北京师范大学资源科学研究所北京100875

中国过去在城市化问题上存在着认识误区 ,制约了城市化进程 ,致使中国现阶段的城市化水平还比较低。经过 2.0多年的改革开放 ,中国城市化水平目前正处于一个由低水平向中等水平过渡的快速发展时期。中国的城市化应该由控制大城市、积极... 详细信息

中国过去在城市化问题上存在着认识误区 ,制约了城市化进程 ,致使中国现阶段的城市化水平还比较低。经过 2.0多年的改革开放 ,中国城市化水平目前正处于一个由低水平向中等水平过渡的快速发展时期。中国的城市化应该由控制大城市、积极发展中小城市和小城镇的模式。

关键词：城市化城镇发展中国家

PREPARATION AND PROPERTIES OF THE NEW ORGANIC CONDUCTOR （BEDT-TTF）₃Cu_2./sub>Cl₄

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1994年第1期5卷 89-92页

作者： Pei Ji WU Xue Yong YANG and Dao Ben ZHU (institute of Chemistry, Academia Sinica,beijing {2.)

In this communication we report the preparation and some electronic properties of (BEDT-TTF)3Lu2.l4.

关键词： Cl BEDT-TTF PREPARATION AND PROPERTIES OF THE NEW ORGANIC CONDUCTOR Cu

Water Security Problem in North china: Research and Perspective

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2005年第5期15卷 563-575页

作者： XIA Jun LIU Meng-Yu JIA Shao-Feng Key Laboratory of Water Cycle ＆Related Land Surface Processes Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 （China） State Key Laboratory of Water Resources ＆ Hydropower Engineering Sciences Wuhan University Wuhan 430072（China） Center for Agricultural Resources Research Institute of Genetic and Developmental Biology Chinese Academy of Sciences Shijiazhuang 050021 （China）

This paper addresses the emergence of water security problems in North china with the aim of highlighting key waterresources management and water security issues for the long-term development of North china. Three key problemsrelated to water resources and security issues in North china in the 2.st century are addressed, namely 1) the watercycle under environmental change, 2. agricultural water saving, and 3) water security. Development of internationalresearch related to these issues is also reviewed. The research plan developed recently by the Chinese Academy of Sciences(CAS) is discussed and suggestions on research and development of water resources science in North china are *** to focus on experimental catchments and dedicated research stations, a detailed knowledge of the water cycle onNorth china farmland has been compiled. A range of techniques that include isotope tracers has been used to acquirehydrologic data. Much research has been devoted to developing distributed hydrological models at different scales. In thewell irrigation district, five different water saving irrigation regimes have been investigated, and these regimes have hadwidespread application, and reduced water use 60-150 mm while they increased water use efficiency (WUE) by 2.%-30%.Furthermore, preventing water pollution is the most essential step to ensure North china’s water security.

关键词： environmental change North china water cycle water resources water security

在线全文

学校读者我要写书评

暂无评论

液相色谱荧光衍生法在糖类物质分析中的应用

色谱 2003年第2期21卷 115-120页

作者：徐瑾张庆合张维冰王风云李彤南京理工大学江苏南京210094 中国科学院大连化学物理研究所国家色谱研究分析中心大连依利特分析仪器有限公司辽宁大连116011

介绍了目前在液相色谱荧光衍生法分析糖类物质中常用的几类荧光衍生试剂及相应的衍生方法,对近期糖类物质分离分析中的液相色谱荧光检测方法做了系统综述。引用文献60篇。

关键词：液相色谱荧光衍生法糖类物质分析荧光检测

A STUDY OF PACKING STRUCTURE OF POLY(P-PHENYLENE BENZOBISTHIAZOLE)BY MOLECULAR SIMULATION

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1993年第9期4卷 779-782页

作者： Yue LIU Chemistry Department,Mudanjiang Teacher’s College,Dongjingcheng 15742.Xiao Zhen YANG Polymer physics Laboratory,institute of Chemistry,Academia Sinica,{2. 100080

Molecular simulation technique was used in an examination of the possibilities of chain packing in the crystalline state for poly(ρ-phenylene benzobisthiazole).It has been found that one reason of hardly forming very ordered crystal of the polymer is the existence of so many stable positions of interchain interaction along chain axis.

关键词： A STUDY OF PACKING STRUCTURE OF POLY P-PHENYLENE BENZOBISTHIAZOLE)BY MOLECULAR SIMULATION

A Preliminary Study on Traditional Level-trench Method to Prevent Rill Initiation in the Three Gorges Region,china

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2011年第6期8卷 876-881页

作者： YAN Dongchun WEN Anbang HE Xiubin SHI Zhonglin XIONG Donghong LONG Yi Key Laboratory of Mountain Environment Evolution and Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu Sichuan 610041 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

The level-trench method is a traditional tillage operation to develop a drainage system on slope land in the Three Gorges region. Before crops are planted, farmers prepare the land with level trenches spaced 3-1o m apart, depending on the slope gradient： steeper slopes require shorter distances. Little scientific analysis has been done on the use of traditional level trenches for soil conservation. We conducted a field investigation and simulation experiments, and present a comparison between the spacing of level trenches and the slope length required for rill initiation. The results indicate that the spacing of level trenches in farmland is close to the slope length required for rill initiation in the experimental plots, and regression models of trench spacing with the gradient and the slope length required for rill initiation with the gradient have similar formats; the coefficients of determination （R2. for the two equations are 0.99 and 0.88, respectively. There were some differences between the field survey and experiments, but we conclude that the traditional level-trench method has an important role in preventing rill initiation.

关键词： Level trench Rill Initiation Purple Soil Three Gorges Region

STUDY ON TYPES OF SOLID SOLUTION IN Al-Ni BINARY SYSTEM BY POSITRON ANNIHILATION

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1989年第12期34卷 989-992页

作者：黄懋容顾华张预民 institute of High Energy physics Academia Sinica Beijing institute of physics Academia Sinica Beijing I. INTRODUCTIONThe ideal composition of δphase in Al-Ni binary system is Ni_2Al_3. Its homogeneous range is from 38.50 to 42.19 at.%Ni at room temperature. The unit cell volume varies with Ni content and has a minimum in ideal composition.In Al-Ni binary system NiAl is the ideal composition of βphase which has a homogeneous range from 45.25 to 60.10 at.%Ni at room temperature and the structure of βphase consists of two lattices of primary cube to penetrate into each

I. INTRODUCTIONThe ideal composition of δ phase in Al-Ni binary system is Ni2.l3. Its homogeneous range is from 38.50 to 42.19 at.%Ni at room temperature. The unit cell volume varies with Ni content and has a minimum... 详细信息

I. INTRODUCTIONThe ideal composition of δ phase in Al-Ni binary system is Ni2./sub>Al3. Its homogeneous range is from 38.50 to 42.19 at.%Ni at room temperature. The unit cell volume varies with Ni content and has a minimum in ideal *** Al-Ni binary system, NiAl is the ideal composition of β phase, which has a homogeneous range from 45.2. to 60.10 at.%Ni at room temperature, and the structure of β phase consists of two lattices of primary cube to penetrate into

关键词： positron annihilation Al-Ni binary system solid solution.

电荷-宇称(CP)对称性破坏和夸克-轻子味物理——写在CP破坏发现和夸克理论提出40周年之际

在线全文

学校读者我要写书评

暂无评论

物理 2004年第12期33卷 882-889页

作者：吴岳良中国科学院理论物理研究所北京100080

简要地介绍了与电荷-宇称(CP)对称性破坏和夸克-轻子味物理有关的一些重要进展.从1964年发现CP破坏和提出夸克理论至今,这个领域就一直成为粒子物理研究的前沿领域,已研究和发展了整整40年,取得了许多辉煌的成就.在这篇文章中,着重评述... 详细信息

简要地介绍了与电荷-宇称(CP)对称性破坏和夸克-轻子味物理有关的一些重要进展.从1964年发现CP破坏和提出夸克理论至今,这个领域就一直成为粒子物理研究的前沿领域,已研究和发展了整整40年,取得了许多辉煌的成就.在这篇文章中,着重评述了目前仍然热门的几个主要的研究方向:直接CP破坏的理论研究和实验验证,CP破坏机制和新的CP破坏源,中微子物理和新的味物理,夸克味物理和有效量子场理论,标准模型中味物理参数的预言和超对称大统一理论.同时对我国有关研究组在这些前沿方向做出的重要贡献作了重点简述.可以看出,在CP破坏和味物理这个重要前沿领域,仍然存在着许多未解之谜,使得粒子物理在2.世纪既面临着巨大的挑战,又有着不断发展的机遇.

关键词： CP破坏夸克轻子粒子物理对称性电荷超对称前沿领域发现理论