检索结果-南通市图书馆

Site 0ccupancy of Alloying Elements and Their Effects on the D0_3 Phase Stability in Fe_3Al

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1999年第4期15卷 339-341页

作者： Jun CAF Shaojun LIU Ying LOU and Benkuan usDepartment 0f Physics, Beijing N0rmal University, Beijing lO0875, ChinaSuqing D UANInstitute of Applied Physics and Computati0nal Mathematics, Beijing 100088, China Department of Physics Beijing Normal University Beijing 100875 China Institute of Applied Physics and Computational Mathematics Beijing 100088 China

The effects of ternary solutes Ti, Co, V, Cr, Ta, W and Mo on the D03 phase 5tability of Fe3Alintermetallics are investigated by tight-binding linear Muffin-tin orbitaI method. The predictedsite preference5 of these elements in Fe3AI are in agreement with the experimental *** calculated Iocal magnetic moment of Fe3AI is identical to the experimentaI. ln addition, itis found that the D03 phase stability of Fe3AI doped with Ti, V, Co and Cr depends on 'energygap- of energy band near Fermi level. while the D03 phase stability of Fe3AI doped with Ta, Wand Mo may be affected by Madelung energy.

关键词： Al Fe Site 0ccupancy of Alloying Elements and Their Effects on the D03 Phase Stability in Fe3Al

HOT EMBOSSING METHODS FOR PLASTIC MICROCHANNEL FABRICATION

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2006年第2期19卷 223-225页

作者： LIU Junshan WANG Liding LIU Chong LU0 Yi Key Laboratory for Micro/Nano Technology and System of Liaoning Province Dalian University of TechnologyDalian 116023 China

Fabrication of microchannels on polymethylmethacrylate （PMMA） substrates using novel microfabrication methods is demonstrated. The image of microchannels is transferred from a silicon master possessing the inverse image of the microchannel to a PMMA plate by using hot embossing methods. The silicon master is electrostatically bonded to a Pyrex 7740 glass wafer, which improves the device yield from about 20 devices to hundreds of devices per master. Effects of embossing temperature, pressure and time on the accuracy of replication are systematically studied using the orthogonal factorial design. According to the suggested experimental model, the time for the whole embossing procedure is shorten from about 20 min to 6 min, and the accuracy of replication is 99.3%. The reproducibility of the hot embossing method is evaluated using 10 channels on different microfluidic devices, with variations of 1.4 % in depth and 1.8% in width.

关键词： Microchannel Microfluidics Hot embossing Plastic Polymethylmethacrylate (PMMA)

Retrofitting of RC Slabs Against Explosive Loads

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2006年第B9期12卷 88-93页

作者： WU Chengqing 0EHLERS Deric John XIA Shaohua School of Civil and Environmental Engineering The University of Adelaide Australia Defence Science and Technological Organization Australia

With the increase of terrorist bomb attacks on buildings, there is a need to develop advanced retrofitting techniques to strengthen structures against blast loads. Currently, several guidelines including an Australian version for retrofitting reinforced concrete (RC) structures are available for the design of retrofitting systems against seismic and monotonic loads using steel or fibre reinforced polymer (FRP) plates that can be either adhesively bonded to the surface or near surface mounted to the concrete cover. However, none of these guidelines provide advice suitable for retrofitting structures subjected to blast loads. In this paper, numerical models are used to simulate the performance of retrofitted RC slabs subjected to blast loads. Airblast pressure distributions on the surface of the slabs estimated in a previous study are used as input in the analysis. A material damage model developed previously for concrete and an elastoplastic model for steel bars are employed in this research for modelling reinforced concrete behaviour due to explosive loads. The material models and blast loading are coded into a finite element computer program LS-DYNA3D to do the analysis. With the numerical model, parametric studies are conducted to investigate RC slabs retrofitted by either externally bonded or near-surface mounted plates or GFRP sheets subjected to blast loads. Discussion is made on the effectiveness of the retrofitting system for RC slabs against blast loads.

关键词： retrofit explosion fibre reinforced polymer slab

在线全文

学校读者我要写书评

暂无评论

催化性抗体及其研究进展

生物化学与生物物理进展 1997年第3期24卷 198-203页

作者：胡昌勤中国药品生物制品检定所北京100050

根据过渡态理论 ,按特定的化学反应机制确定反应中的可能过渡态结构 ,选择和该过渡态结构类似的化合物作为半抗原 ,可诱导机体产生具有催化活性的催化性抗体 .文章对诱导催化性抗体中半抗原的选择原则、催化性抗体和非催化性抗体间的联... 详细信息

根据过渡态理论 ,按特定的化学反应机制确定反应中的可能过渡态结构 ,选择和该过渡态结构类似的化合物作为半抗原 ,可诱导机体产生具有催化活性的催化性抗体 .文章对诱导催化性抗体中半抗原的选择原则、催化性抗体和非催化性抗体间的联系、催化性抗体和酶促催化反应的比较等方面进行了较为全面的综述。

关键词：催化性抗体抗体

Development of setal patterns in embryonic and adult aphids of the Hormaphidinae （Hemiptera： Aphididae）

在线全文

学校读者我要写书评

暂无评论

Insect Science 2007年第4期14卷 339-350页

作者： LI-YUN JIANG GE-XIA QIA0 GUANG-XUE ZHANG Institute of Zoology Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences BeijingChina

The elementary traits and diversity of embryonic setal patterns of 31 species of 22 genera, in three tribes of Hormaphidinae are studied. The embryonic setal patterns to every species are provided. Based on the parsimony principle and the developmental principle, these patterns are analyzed in each tribe following the terminology of Richards （1965）. It is suggested that the setal patterns of abdominal tergites are the most important characters in embryonic and adult setal patterns. In conclusion, neoteny is a phylogenetic trend in the Hormaphidinae. Nipponaphidini and Hormaphidini have more typical neoteny in each genus and more diversity in different types of adult viviparous females than Cerataphidini, by showing more frequent and various protopatterns or mesopatterns.

关键词： Hemiptera Hormaphidinae embryo adult setal pattern development neo-teny

Phase Transition for Dielectric Breakdown Model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 1997年第4期2卷 201-206页

作者： Fuxuan CHANG &Houqiang LI &De L IU &L ibin L IN (Department of Physics. Open laboratory of Radiation Physics and Technology,Sichuan University,Chengdu,6 1 0 0 6 4,China) 1The paper was received on Nov. 2 0 ,1997 Department of Physics Open laboratory of Radiation Physics and Technology Sichuan University Chengdu 610064 China

In this paper,the phase transition for DBM whenηvaries is investigated by using real- space renormalization-group method. The resultdemonstrates that there are phase transitions for almost all the value ofη,and we f... 详细信息

关键词： DBM phase transition renormalization-group

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

蛋白质磷酸化作用的结构基础

生物化学与生物物理进展 1997年第4期24卷 290-295页

作者：李林中国科学院上海生物化学研究所上海200031

蛋白质可逆磷酸化涉及到几乎所有细胞活动的调节 .

关键词：蛋白质磷酸化结构基础调节作用

Pt Complexes with High Molecular Weight Polyvinylmethyldimethylsiloxane Ligands Supported on Diatomite for Liquid-phase Hydrosilylation of 3, 3, 3-Trifluoropropene with Methyldichlorosilane

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第6期17卷 803-806页

作者： Hong Liu LIA0 Huai Jun ZHU Feng Yi LI College of Chemical and Energy South China University of Technology Guangzhou 510640 Chemistry Department of Nanchang University Nanchang 330047

Pt complexes with high molecular weight polyvinylmethyldimethylsiloxane （HMPVMS） ligands supported on diatomite as a catalyst for the hydrosilylation of 3, 3, 3-trifluoropropene and methyldichlorosilane. Results show that this catalyst displays good thermal stability, high activity and excellent recyclability, and it can be readily fabricated by a simple process.

关键词： Pt hydmsilylation high molecular weight polyvinylmethyldimethylsiloxane.

ALGORITHM AND IMPLEMENTATION OF AUTO-SEARCHING WELD LINE FOR WELDING MOBILE ROBOT

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2006年第2期19卷 176-180页

作者： ZHANG Ke Lü Xueqin　 WU Yixiong L0U Songnian Institute of Welding Engineering Shanghai Jiaotong UniversityShanghai 200030 China

An algorithm of auto-searching weld line for welding mobile robot is presented. Auto-searching weld line is that the robot can automatically recognize a weld groove according to the characteristics of the weld groove before welding, and then adjust itself posture to the desired status preparing for welding, namely, it is a process that the robot autonomously aligns itself to the center of welding seam. Firstly, the configuration of welding mobile robot with the function of auto-searching weld line is introduced, then the algorithm and implementation of auto-searching weld line are presented on the basis of kinematics model of the robot, at last trajectory planning among auto-searching weld line is investigated in detail. The experiment result shows that the developed welding mobile robot can successfully implement the task of auto-searching weld line before welding, tracking error precision can be controlled to approximate ±1.5 mm, and satisfy the requirement of practical welding project.

关键词： Welding mobile robot Auto-searching weld line Trajectory planning