首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2475篇
  免费   51篇
  国内免费   68篇
电工技术   8篇
综合类   33篇
化学工业   52篇
金属工艺   8篇
机械仪表   19篇
建筑科学   133篇
矿业工程   8篇
能源动力   12篇
轻工业   51篇
水利工程   8篇
石油天然气   10篇
武器工业   2篇
无线电   90篇
一般工业技术   34篇
冶金工业   1238篇
原子能技术   5篇
自动化技术   883篇
  2020年   16篇
  2017年   25篇
  2016年   39篇
  2015年   27篇
  2014年   64篇
  2013年   64篇
  2012年   81篇
  2011年   109篇
  2010年   111篇
  2009年   154篇
  2008年   132篇
  2007年   176篇
  2006年   181篇
  2005年   125篇
  2004年   105篇
  2003年   106篇
  2002年   77篇
  2001年   54篇
  2000年   41篇
  1999年   25篇
  1998年   20篇
  1997年   24篇
  1995年   27篇
  1994年   15篇
  1992年   17篇
  1990年   20篇
  1989年   29篇
  1988年   26篇
  1987年   19篇
  1986年   43篇
  1985年   27篇
  1984年   21篇
  1982年   19篇
  1981年   30篇
  1979年   17篇
  1977年   17篇
  1976年   15篇
  1975年   17篇
  1973年   19篇
  1971年   25篇
  1970年   21篇
  1969年   23篇
  1968年   46篇
  1967年   15篇
  1966年   21篇
  1965年   32篇
  1964年   27篇
  1961年   15篇
  1958年   14篇
  1956年   18篇
排序方式: 共有2594条查询结果,搜索用时 15 毫秒
941.
The Distinguished Career Contributions Award recognizes continuous significant contributions made over a lifelong career in psychology; the Distinguished Contributions Award recognizes a more specific contribution to education and training. The 2008 recipient for the Distinguished Career Contributions to Education and Training is Rex Lloyd Forehand. There was no 2008 recipient for the Award for Distinguished Contributions to Education and Training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
942.
An uncompromising advocate of academic rigor, and the last surviving second-generation Gestalt theorist, Mary Henle maintained the highest academic standards during a long career that was an inspiration to many of her colleagues. Her frequently cited publications are models of clear thinking and clear writing. She served as president of the Eastern Psychological Association (1981-1982) and of Divisions 24 (Theoretical and Philosophical Psychology, 1974-1975) and 26 (History of Psychology, 1971-1972) of the American Psychological Association (APA). She also served on such boards and committees as the APA Insurance Trust and made many presentations of carefully crafted papers at psychology conventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
943.
The interactions between paper coating lubricants and a carboxylated styrene/butadiene latex emulsion and their effect on latex film morphology have been studied. Calcium stearate, non-ionic polyethylene emulsion and organic triglyceride lubricants showed different interaction characteristics with the latex emulsion according to viscosity, zeta potential and isothermal calorimetric measurements. Calcium stearate lowered the viscosity of the dilute latex emulsion at low concentration suggesting a strong interaction with the latex particles due to a change in the hydrodynamic dimensions of the latex particles. The exothermic enthalpy change supported the assumption of a dissociative interaction. In contrast, both non-ionic polyethylene and organic triglyceride emulsion showed less pronounced enthalpy changes, indicating lower affinity for the latex particles. The reduction in viscosity showed, however, that at low lubricant concentrations there is an interaction between the latex particles and particularly the organic triglyceride emulsion. This suggests a selective adsorption of stabilizing agents and species from the lubricant emulsion which alters the hydrodynamic radius of the latex particles. The effects of the colloidal interactions on the morphology of the latex films monitored by Atomic Force Microscopy (AFM) indicated that specific surface interaction occurring in aqueous media influenced the topography and the surface chemical heterogeneity of the latex films. Especially in the case of calcium stearate, it seems that the dissolved species arrange themselves around the latex particles inhibiting film formation. The organic triglyceride, on the other hand, showed a lower interaction potential in the aqueous phase and it had a different impact on the film formation.  相似文献   
944.
回顾了五棵松体育馆设计经历的三个主要阶段,而这三个阶段采用了三种模式,分别体现了对大型体育场馆赛后利用的三种思路。  相似文献   
945.
杜宏武  郭谦 《中国园林》2006,22(5):43-46
居住的社区重构是当前的一个重大课题,邻里交往的形成、频度和强度等与住区环境有密切关系.把邻里交往放在社区重构这样一个大的视野下,通过对珠江三角洲11个住区的调研,可概括地反映本地区近年建成住区的邻里交往状况,并对规划设计观念提出思考.  相似文献   
946.
Based in London and Beijing, Groundlab is an emerging international practice that specialises in landscape urbanism. Eva Castro, José Alfredo Ramírez and Eduardo Rico of Groundlab describe the potential that the ground itself provides for a new urbanism, which is able to integrate multiple fields and scales while also engaging with greater territorial systems. They explain how landscape architect Frederick Law Olmsted was influential in establishing an approach that uses ecological infrastructure as the basis for design. They proceed in describing two Groundlab projects that integrate ground remediation and water infrastructure techniques: Paisajes Latentes urban design masterplan for Valle De Chalco Solidaridad in Mexico City (2011) and the Ground Ecologies masterplan for the redevelopment of the Jiading District in Shanghai (2010).  相似文献   
947.
在无线传感器网络(WSN)中,传感器关联规则在很多方面有着重要作用。但是大部分关联规则的数据挖掘算法都要求获取传感器节点的行为数据。同时,将这些数据传输到sink节点,并且由sink节点创建传感器数据库,并应用不同的算法从传感器数据库来发现关联规则。本文则提出了一个网络内部机制来查找频繁项集。因此,节点只发送传感器频繁模式到sink节点,而不是节点整个活动集,从而节省sink节点开销。  相似文献   
948.
We have investigated the Hg2+ transport from Crystal Violet Lactone to Fluoran dye based on the association constant, Kass. Upon addition of Hg2+, the Crystal Violet Lactone shows a new peak at around 603 nm, and the color of the solution changed from colorless to blue. With the addition of Fluoran dye in this solution containing Crystal Violet Lactone and Hg2+, the absorption intensity of Fluoran dye at 447 nm and 586 nm was all increased. So the color of solution gradually became black from blue color. From the changes of the ratio A586/A447, it is apparent that the Hg2+ in Crystal Violet Lactone-Hg2+ was transported to colored Fluoran. The Hg2+ transport from Crystal Violet Lactone to Fluoran dye was also carried out by the calculation of the association constant: the binding ability for the complex formation of Fluoran dye and Crystal Violet Lactone-Hg2+ is much greater in CH3CN solution (Kass = 3.0 × 104 M−1) than that of the Crystal Violet Lactone with Hg2+ (Kass = 1.2 × 103 M−1).  相似文献   
949.
The verdant gardens of ancient Persia are a testament to this highly developed culture's resourcefulness and ability to not only source and direct water and irrigate the land in a hostile environment, but then to transform it into a manmade paradise. Here, Nasrine Faghih and Amin Sadeghy provide a historic outline of Persian garden typologies and their evolution over time, providing a focus on the central kiosk within the enclosed garden, highlighting the synergy between climate, resources and place.  相似文献   
950.
A number of powerful individuals have played a significant role promoting regeneration in London. Peter Murray describes some of those who make up this important network of politicians, civil servants, planners and developers. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号