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   1174篇
  免费   36篇
  国内免费   9篇
电工技术   10篇
综合类   1篇
化学工业   156篇
金属工艺   18篇
机械仪表   18篇
建筑科学   99篇
矿业工程   30篇
能源动力   48篇
轻工业   67篇
水利工程   5篇
石油天然气   8篇
无线电   126篇
一般工业技术   139篇
冶金工业   174篇
原子能技术   27篇
自动化技术   293篇
  2022年   4篇
  2021年   10篇
  2020年   8篇
  2019年   11篇
  2018年   16篇
  2017年   19篇
  2016年   19篇
  2015年   15篇
  2014年   19篇
  2013年   98篇
  2012年   47篇
  2011年   45篇
  2010年   31篇
  2009年   44篇
  2008年   47篇
  2007年   64篇
  2006年   62篇
  2005年   60篇
  2004年   56篇
  2003年   54篇
  2002年   36篇
  2001年   32篇
  2000年   33篇
  1999年   34篇
  1998年   44篇
  1997年   37篇
  1996年   33篇
  1995年   24篇
  1994年   19篇
  1993年   14篇
  1992年   8篇
  1991年   12篇
  1990年   9篇
  1989年   9篇
  1988年   5篇
  1987年   11篇
  1986年   12篇
  1985年   17篇
  1984年   11篇
  1983年   8篇
  1982年   7篇
  1981年   6篇
  1980年   7篇
  1979年   10篇
  1978年   4篇
  1977年   8篇
  1976年   10篇
  1975年   7篇
  1973年   4篇
  1963年   3篇
排序方式: 共有1219条查询结果,搜索用时 15 毫秒
101.
Items from California Adult Q-Sort (CAQ) were used to assess psychosocial generativity (E. H. Erikson, 1950) in a sample of educated women at midlife. CAQ scores measured at age 43 demonstrated convergent validity with an inventory measure of generativity assessed at age 53. According to other longitudinal analyses, women who attained a generative stance at age 43 reported greater investment 10 years later in intergenerational roles (e.g. daughter, mother) but not nonintergenerational ones (e.g. friend, sister). Generative women also reported less subjective burden in caring for aging parents and more knowledge about community elder care programs. Further evidence suggests that participants felt embedded in a reciprocal caregiving network in which they themselves are recipients of care. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
102.
This is the second of two papers surveying research in coordination approaches and systems. This paper is concerned with operational coordination, which is aimed at coordinating activities such that the design process can be performed in a near optimal manner with respect to time, and the allocation and utilisation of resources. Aspects of coordination categorised as operational include resource management, scheduling and planning. The first of these two papers presents a review of coordination from a strategic perspective, which is concerned with the decision management aspects of coordination. Greater emphasis is now being placed on the significance of organising the design process as this affects time to market, product quality, cost, and consequently product success. The aim of this paper is to present a fundamental review of operational coordination approaches and systems. The 1990s has seen much progress being made towards a greater understanding and appreciation of coordination in various disciplines through the development of a wide range of approaches and systems. However, there remains a requirement to formally identify the key issues involved in coordination such that a widely accepted representation can be agreed upon. Consequently, research should continue to be supported in the exploration for a unified approach to coordination which will permit a broader and greater understanding of those aspects involved.  相似文献   
103.
104.
Site monitoring is an indispensable procedure in construction quality control. It does not only minimize construction defects and human errors but also supports project team members making strategic decisions at critical points throughout the construction stages. This paper presents a cost-effective construction site monitoring system integrating a long-range wireless network, network cameras, and a web-based collaborative platform. The system supports simultaneous user access therefore project team members could view real-time captured images or video of a construction site, discuss and exchange ideas with gadgets such as video conference, text and shared whiteboard at a distance via the Internet. It was carefully configured in order to maintain the reliability under the reactive conditions of the construction sites. The system has been implemented and tested on two construction sites and promising results were obtained.  相似文献   
105.
106.
This field experiment examined effects of a support intervention on the physical and mental health of coronary artery bypass graft (CABG) surgery patients. Control participants (N?=?90) received usual hospital care; experimental participants (N?=?100) also received visits from a "similar other" while in the hospital. Similar others were Veterans Administration veterans who had CABG surgery previously and were trained in simple supportive techniques. Outcomes were assessed prior to surgery and at 1, 6, and 12 months afterwards. Unexpectedly, the intervention generally had no effects on participants' well-being. Further analysis showed that participants who talked often with fellow cardiac patients in the hospital ("de facto similar others") experienced improvements in their physical and emotional well-being over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
107.
Bill Boni 《Network Security》2002,2002(4):18-19
In what may turn out to be one of the most interesting incidents of early 21st century electronic business, a French company, Canal+ Group and two subsidiaries recently filed a lawsuit in US District Court for Northern California against NDS Group [NASDAQ:NNDS]. The basis for the complaint is that NDS, a UK-based company ‘spent large amounts of money and resources’ to break the security system underlying Canal+’s digital TV smartcard. The suit claims that NDS masterminded ‘a conspiracy to harm Canal+’s competitive position in the digital television market.’ The plaintiffs allege violations of US copyright law and the Racketeer Influenced and Corrupt Organizations Act, as well as the California Unfair Competition statute, all of which carry very serious penalties.  相似文献   
108.
109.
Bill 《Refocus》2004,5(5):56-57
  相似文献   
110.
[Fe]‐Hydrogenase (Hmd) catalyzes reversible hydride transfer from H2. It harbors an iron‐guanylylpyridinol as a cofactor with an FeII that is ligated to one thiolate, two COs, one acyl‐C, one pyridinol‐N, and solvent. Here, we report that CuI and H2O2 inactivate Hmd (half‐maximal rates at 1 μM CuI and 20 μM H2O2) and that FeII inhibits the enzyme with very high affinity (Ki=40 nM ). Infrared and EPR studies together with competitive inhibition studies with isocyanide indicated that CuI exerts its inhibitory effect most probably by binding to the active site iron‐thiolate ligand. Using the same methods, it was found that H2O2 binds to the active‐site iron at the solvent‐binding site and oxidizes FeII to FeIII. Also it was shown that FeII reversibly binds away from the active site iron, with binding being competitive to the organic hydride acceptor; this inhibition is specific for FeII and is reminiscent of that for the [FeFe]‐hydrogenase second iron, which specifically interacts with H2.  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