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   26384篇
  免费   1072篇
  国内免费   719篇
电工技术   1334篇
技术理论   16篇
综合类   2240篇
化学工业   1644篇
金属工艺   225篇
机械仪表   405篇
建筑科学   9394篇
矿业工程   762篇
能源动力   553篇
轻工业   3387篇
水利工程   3912篇
石油天然气   627篇
武器工业   46篇
无线电   577篇
一般工业技术   876篇
冶金工业   561篇
原子能技术   86篇
自动化技术   1530篇
  2025年   158篇
  2024年   328篇
  2023年   353篇
  2022年   374篇
  2021年   482篇
  2020年   496篇
  2019年   372篇
  2018年   392篇
  2017年   431篇
  2016年   641篇
  2015年   743篇
  2014年   2217篇
  2013年   1430篇
  2012年   1896篇
  2011年   2031篇
  2010年   1827篇
  2009年   1921篇
  2008年   1626篇
  2007年   2083篇
  2006年   1657篇
  2005年   1376篇
  2004年   1133篇
  2003年   1001篇
  2002年   770篇
  2001年   561篇
  2000年   424篇
  1999年   298篇
  1998年   236篇
  1997年   188篇
  1996年   170篇
  1995年   148篇
  1994年   107篇
  1993年   67篇
  1992年   34篇
  1991年   21篇
  1990年   20篇
  1989年   30篇
  1988年   23篇
  1987年   13篇
  1986年   9篇
  1985年   21篇
  1984年   16篇
  1983年   31篇
  1982年   4篇
  1980年   3篇
  1979年   2篇
  1977年   3篇
  1966年   1篇
  1958年   2篇
  1956年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
An alternative approach to understanding innovation is made using two intersecting ideas. The first is that successful innovation requires consideration of the social and organizational contexts in which it is located. The complex context of construction work is characterized by inter-organizational collaboration, a project-based approach and power distributed amongst collaborating organizations. The second is that innovations can be divided into two modes: 'bounded', where the implications of innovation are restricted within a single, coherent sphere of influence, and 'unbounded', where the effects of implementation spill over beyond this. Bounded innovations are adequately explained within the construction literature. However, less discussed are unbounded innovations, where many firms' collaboration is required for successful implementation, even though many innovations can be considered unbounded within construction's inter-organizational context. It is argued that unbounded innovations require an approach to understand and facilitate the interactions both within a range of actors and between the actors and technological artefacts. The insights from a sociology of technology approach can be applied to the multiplicity of negotiations and alignments that constitute the implementation of unbounded innovation. The utility of concepts from the sociology of technology, including 'system building' and 'heterogeneous engineering', is demonstrated by applying them to an empirical study of an unbounded innovation on a major construction project (the new terminal at Heathrow Airport, London, UK). This study suggests that 'system building' contains outcomes that are not only transformations of practices, processes and systems, but also the potential transformation of technologies themselves.  相似文献   
2.
Meeting time and cost objectives in complex projects involves specific problems and risks. An attempt is made to analyse the components of total cost increase of a project caused by time delay. An outline is given as to how these considerations can be used to estimate cost increases in investors' decision situations as well as to ascertain fair contractual penalties and claims for compensation and for the evaluation of justified project acceleration costs.  相似文献   
3.
Results from applying the model on a sample of contractors, the majority of whom were international and operating in Egypt, reinforces the credibility of the developed methodology, claim the authors.  相似文献   
4.
5.
6.
Istanbul is one of the most famous historical cities in the world. However, the project alignment selected as the best of a range of alignments cannot avoid passing beneath the historical and cultural heritages of Istanbul as well as under ancient and densely inhabited areas of the city. This paper will explain some of the challenges related to the bored tunnels.

Historical buildings are vulnerable. Yet many existing residential and office buildings are old and constructed on minimal foundations. As a consequence, it is vital that any drawdown of groundwater and any ground settlements have to be minimized.

In addition, the connection between the immersed and bored tunnels will be made directly and totally underground, without the usual intermediate shafts and beneath the deep waters of the Bosphorus Strait. This operation needs the utmost control of the tunnel excavation face to ensure its stability and to minimize water ingress. Based on such considerations, tunnel excavation by tunnel boring machine (TBM) using a slurry shield and having the ability to operate under high pore pressures was recommended as the method of excavation for the main running tunnels.

The paper will explain how the design team from Avrasyaconsult – the Employer’s Representative – arrived at the final minimum, specific and functional requirements of the bored tunneling works which are to be carried out using the ‘FIDIC EPC/Turnkey Project’ conditions.  相似文献   

7.
建设项目控制的重点应放在投资决策和设计阶段中,否则会造成巨大的损失。这不仅需要人们改革组织结构和管理体制,更需要从根本上转变思想观念。  相似文献   
8.
结合作者的实际工作 ,总结了对工程建设实施“三道质量控制工序”的经验 ,强调了过程质量控制的重要性 ,较为系统地介绍了化工建设项目预验收工作的程序和内容  相似文献   
9.
随着我国社会经济的发展,人们对建筑的质量要求越来越高,建筑工程项目管理的作用也越来越大,其对保证建筑工程的实施和质量有着十分重要的意义。通过分析建筑项目管理工作的作用和具体内容,提出了改善和创新的方法和措施,以供相关单位借鉴和参考。  相似文献   
10.
以棉浆为原料,废盐酸为水解催化剂,所得合成革用微晶纤锥素增粘剂的质量指标达到了德国和日本同类产品的标准。  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