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   1675篇
  免费   7篇
电工技术   1篇
化学工业   25篇
金属工艺   4篇
机械仪表   24篇
建筑科学   13篇
能源动力   5篇
轻工业   8篇
石油天然气   2篇
无线电   26篇
一般工业技术   32篇
冶金工业   1507篇
原子能技术   3篇
自动化技术   32篇
  2019年   2篇
  2018年   4篇
  2017年   5篇
  2016年   4篇
  2014年   2篇
  2013年   10篇
  2012年   5篇
  2011年   19篇
  2010年   12篇
  2009年   14篇
  2008年   12篇
  2007年   19篇
  2006年   5篇
  2005年   5篇
  2004年   11篇
  2003年   14篇
  2002年   8篇
  2001年   8篇
  2000年   9篇
  1999年   41篇
  1998年   374篇
  1997年   235篇
  1996年   149篇
  1995年   75篇
  1994年   86篇
  1993年   92篇
  1992年   18篇
  1991年   35篇
  1990年   35篇
  1989年   33篇
  1988年   42篇
  1987年   26篇
  1986年   15篇
  1985年   23篇
  1984年   4篇
  1983年   6篇
  1982年   9篇
  1981年   10篇
  1980年   10篇
  1979年   3篇
  1978年   5篇
  1977年   61篇
  1976年   98篇
  1975年   9篇
  1973年   3篇
  1971年   2篇
  1970年   3篇
  1965年   3篇
  1956年   1篇
  1955年   2篇
排序方式: 共有1682条查询结果,搜索用时 15 毫秒
1.
The bromodomain and extra terminal (BET) family of bromodomain-containing proteins (BCPs) have been the subject of extensive research over the past decade, resulting in a plethora of high-quality chemical probes for their tandem bromodomains. In turn, these chemical probes have helped reveal the profound biological role of the BET bromodomains and their role in disease, ultimately leading to a number of molecules in active clinical development. However, the BET subfamily represents just 8/61 of the known human bromodomains, and attention has now expanded to the biological role of the remaining 53 non-BET bromodomains. Rapid growth of this research area has been accompanied by a greater understanding of the requirements for an effective bromodomain chemical probe and has led to a number of new non-BET bromodomain chemical probes being developed. Advances since December 2015 are discussed, highlighting the strengths/caveats of each molecule, and the value they add toward validating the non-BET bromodomains as tractable therapeutic targets.  相似文献   
2.
A discussion is presented of contributing factors to the injury to the foreleg of the Thoroughbred racehorse. The critical part of the step is taken to be the first 10-20 ms after ground contact as the hoof slides forward and stops. Large nonaxial loads associated with the deceleration of the hoof are shown to arise. Results of accelerometer measurements on the hoof of a horse running at racing speed are presented as well as mechanical properties of the racing surface. The mechanical properties of the track surface, the type of shoe, and the degree of fatigue of the horse all work together to determine the level of risk.  相似文献   
3.
4.
The prevalence of human herpesvirus 8 (HHV-8)/Kaposi's sarcoma (KS)-associated herpesvirus was investigated in the semen of 99 human immunodeficiency virus (HIV)-infected men (median CD4 cell count, 357/mm3) by use of a polymerase chain reaction (PCR) assay capable of detecting <10 copies of HHV-8 DNA. Of the subjects, 95 (96%) self-identified as men who have sex with men (MSM), and 3 had a history of clinical KS. Seminal cell specimens were negative for HHV-8 in 98 subjects. None of the 26 without KS (27.1% of 96 tested) who were seropositive for HHV-8 by IFA for latency-associated nuclear antigens had HHV-8 detected in their semen. The only subject with any evidence for seminal HHV-8 DNA was seropositive for HHV-8 and had active KS. HHV-8 was detected in 10 (10.4%) of 96 peripheral blood mononuclear cell specimens. The prevalence of HHV-8 DNA by PCR in semen of HIV-infected MSM without KS is low.  相似文献   
5.
6.
Argues that while there is potential for successful blending of 12-step approaches and psychotherapies for chemical dependency at the level of helping strategies/techniques, some basic differences in values and philosophy will make it impossible to ever fully integrate the 2 approaches without compromising one or the other approach. Some of the differences between the 2 approaches involve leadership (indigenous vs professional), individual control (increasing vs decreasing), and spirituality (enhanced vs decreased). Given that psychotherapy and the 12-step approach must remain largely independent, a model for interactions based on mutual respect, independent control, and cooperation is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
The biochemical maturation of the lung in late gestation and in the young animal is regulated by glucocorticoids. The present study was aimed at dissociating the different glucocorticoid receptor sites involved in these regulatory functions. The obese Zucker rat was selected as a model for this study as it exhibits hypersensitivity to glucocorticoid hormone action by virtue of its elevated receptor numbers and activity. Two synthetic steroid analogues were administered to obese animals; RU28362, a specific type II receptor agonist, and the type II antagonist RU486. RU28362 promoted a strong catabolic effect, which was associated with reduced food intake and the abolition of growth in the rats. The agonist, RU28362, attenuated developmental increases in antioxidant enzyme activities, and altered the growth of the tissue. At the age studied, development of the lung phosphatidylcholine (PC) system was almost complete, but RU28362 increased disaturated PC 16:0/16:0 concentrations by almost 2-fold, and altered the molecular composition of total pulmonary PC. RU486 attenuated the growth of the rats and reduced their food intake. Treatment with the type II antagonist attenuated lung growth and increased the activities of pulmonary copper zinc (Cu/Zn) and manganese (Mn) superoxide dismutases. RU486 had no effect on lung PC concentrations and molecular composition. The data suggest a role for type I glucocorticoid receptors in the regulation of the antioxidant enzyme system in the lung, as type II antagonism will channel endogenous glucocorticoid binding to the type I site. Type II receptor binding would appear to play a role in regulating the lung PC content.  相似文献   
8.
Several simple 3D experiments are used to provide J correlations between methionine C epsilon methyl carbons and either the C gamma H2 protons or C beta and C gamma. The intensity of the J correlations provides information on the size of the three-bond J couplings and thereby on the chi 3 torsion angle. In addition, a simple 3D version of the HMBC experiment provides a sensitive link between the C epsilon H3 methyl protons and C gamma. The methods are demonstrated for a 20 kDa complex between calmodulin and a 26-residue peptide fragment of skeletal muscle myosin light chain kinase.  相似文献   
9.
10.
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