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   300篇
  免费   7篇
  国内免费   7篇
电工技术   39篇
化学工业   27篇
金属工艺   8篇
机械仪表   3篇
建筑科学   2篇
矿业工程   1篇
轻工业   13篇
水利工程   3篇
石油天然气   2篇
无线电   7篇
一般工业技术   31篇
冶金工业   160篇
原子能技术   8篇
自动化技术   10篇
  2022年   1篇
  2019年   2篇
  2018年   2篇
  2017年   8篇
  2016年   1篇
  2015年   4篇
  2014年   3篇
  2013年   14篇
  2012年   13篇
  2011年   10篇
  2010年   2篇
  2009年   7篇
  2008年   4篇
  2007年   3篇
  2005年   5篇
  2004年   2篇
  2003年   2篇
  2002年   7篇
  2001年   9篇
  2000年   2篇
  1999年   17篇
  1998年   47篇
  1997年   28篇
  1996年   27篇
  1995年   11篇
  1994年   5篇
  1993年   12篇
  1992年   3篇
  1991年   5篇
  1990年   3篇
  1989年   2篇
  1988年   2篇
  1986年   4篇
  1985年   4篇
  1983年   1篇
  1982年   1篇
  1981年   4篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1977年   4篇
  1976年   19篇
  1975年   2篇
  1973年   1篇
  1971年   2篇
  1970年   1篇
  1969年   2篇
  1958年   1篇
  1955年   1篇
排序方式: 共有314条查询结果,搜索用时 15 毫秒
21.
Technology is described for manufacturing dense ceramic from very fine powder based on zirconium dioxide partly stabilized with yttrium oxide. Some engineering properties of the manufactured ceramic are defined. Its microstructure and phase composition are studied. Ceramic properties with impact-wave loading are studied, and values of dynamic elastic limit and spalling strength are obtained.  相似文献   
22.
The possibility of full 100% usage of ash from coal-fired thermal power stations for producing raw materials for the cement and alumina industries is considered, and it is shown that comprehensive processing of ash from coal-fired thermal power stations is required for this purpose.  相似文献   
23.
24.
A mathematical model of radiative heat exchange in the throats of wide-necked helium cryostats is analyzed. A comparison of the numerical results with known calculated and experimental data shows their good agreement.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 4, pp. 627–634, October, 1985.  相似文献   
25.
The influence of a thin layer of arbitrary conductivity on the characteristics of acoustic waves in potassium niobate is investigated theoretically. The conductivity of a thin layer on the surface of a potassium niobate crystal or plate is shown to have a significant influence on the damping and velocity not only of symmetric Lamb waves and quasi-shear-horizontal waves but also of Gulyaev-Bleustein waves. It is found that a relative change in velocity as large as 50% can be achieved for quasi-shear-horizontal waves by altering the surface conductivity. The results obtained reveal great prospects of using potassium niobate to create acoustoelectronic devices with controllable characteristics. Pis’ma Zh. Tekh. Fiz. 25, 21–26 (April 26, 1999)  相似文献   
26.
本文介绍了安森美半导体用于车载网络的创新解决方案,包括CAN收发器NCV7341,LIN收发器NCV7321,以及系统级芯片NCV7420/25 LIN-SBC等。  相似文献   
27.
28.
29.
Currently, the treatment of falciparum malaria is seriously compromised by spreading drug resistance. We studied the effects of camptothecin, a potent and specific topoisomerase I inhibitor, on erythrocytic malaria parasites in vitro. In Plasmodium falciparum, camptothecin trapped protein-DNA complexes, inhibited nucleic acid biosynthesis, and was cytotoxic. These results provide proof for the concept that topoisomerase I is a vulnerable target for new antimalarial drug development.  相似文献   
30.
The diffusion coefficients of two caged fluorescent dyes were measured in free solution and in the lateral intercellular spaces (LIS) of cultured Madin-Darby canine kidney (MDCK) cells after photoactivation by illumination with a continuous or pulsed UV laser. Both quantitative video imaging and a new photometric method were utilized to determine the rates of diffusion of the caged fluorescent dyes: 8-((4,5-dimethoxy-2-nitrobenzyl)oxy)pyrene-1,3,6-trisulfonic acid (DMNB-HPTS) and (4,5-dimethoxy-2-nitrobenzyl) fluorescein dextran (10,000 MW) (DMNB-caged fluorescein dextran). The diffusion coefficients at 37 degrees C in free solution were 3.3 x 10(-6) cm2/s (HPTS) and 0.98 x 10(-6) cm2/s (10,000 MW dextran). Diffusion of HPTS within nominally linear stretches of the LIS of MDCK cells grown on glass coverslips was indistinguishable from that in free solution, whereas dextran showed a 1.6 +/- 0.5-fold reduction in diffusivity. Measurements of HPTS diffusion within the LIS of multicellular regions also exhibited a diffusivity comparable to the free solution value. The restriction to diffusion of the dextran within the LIS may be due to molecular hindrance.  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