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   1758篇
  免费   1篇
电工技术   3篇
化学工业   46篇
金属工艺   4篇
机械仪表   15篇
矿业工程   6篇
轻工业   6篇
水利工程   3篇
石油天然气   5篇
无线电   8篇
一般工业技术   132篇
冶金工业   1520篇
原子能技术   4篇
自动化技术   7篇
  2022年   4篇
  2021年   4篇
  2020年   5篇
  2019年   5篇
  2018年   6篇
  2017年   7篇
  2016年   10篇
  2014年   12篇
  2013年   7篇
  2012年   11篇
  2011年   7篇
  2010年   12篇
  2009年   9篇
  2008年   18篇
  2007年   12篇
  2006年   14篇
  2005年   9篇
  2004年   8篇
  2003年   9篇
  2002年   8篇
  2001年   6篇
  1999年   29篇
  1998年   450篇
  1997年   256篇
  1996年   181篇
  1995年   145篇
  1994年   86篇
  1993年   80篇
  1992年   19篇
  1991年   19篇
  1990年   16篇
  1989年   9篇
  1988年   13篇
  1987年   10篇
  1986年   7篇
  1985年   11篇
  1984年   5篇
  1983年   7篇
  1982年   7篇
  1981年   17篇
  1980年   20篇
  1979年   2篇
  1978年   10篇
  1977年   60篇
  1976年   100篇
  1975年   2篇
  1974年   2篇
  1973年   2篇
  1966年   2篇
  1958年   2篇
排序方式: 共有1759条查询结果,搜索用时 390 毫秒
1.
Basic definitions related to the main electrodynamic characteristics of surface space-charge waves are formulated. These characteristics and their relationships with the geometric dimensions of guiding structures (a dielectric cylinder and a planar metal-dielectric waveguide) are determined.  相似文献   
2.
We characterize the meander of re-entrant excitation in a model of a sheet of mammalian ventricular tissue, and its control by resonant drift under feedback driven stimulation. The Oxsoft equations for excitability in a guinea pig single ventricular cell were incorporated in a two dimensional reaction-diffusion system to model homogeneous, isotropic tissue with a plane wave conduction velocity of 0.35 m s-1. Re-entrant spiral wave solutions have a spatially extended transient motion (linear core) that settles down into rotation with an irregular period of 100-110 ms around an irregular, multi-lobed spiky core. In anisotropic tissue this would appear as a linear conduction block. The typical velocity of drift of the spiral wave induced by low amplitude resonant forcing is 0.4 cm s-1.  相似文献   
3.
The report deals with the development of procedures, evaluation of laser application and prevention of complications involved in intensive chemoradiation therapy of neoplasms of hemopoietic and lymphoid tissue in childhood. The clinical data on 548 patients, aged 2 months-15 years, with leukemia and solid tumor were evaluated. Laser application for treatment of different complications of chemoradiation therapy of pediatric leukemia proved a valuable innovation. It had a pronounced antiinflammatory and analgetic effect, promoted tissue regeneration processes and cut down the duration of complication treatment drastically.  相似文献   
4.
5.
6.
7.
The structural peculiarities of cis-1,4-isoprene rubber, oligodiene diisocyanate, and derivative of phenol–formaldehyde resin blends have been studied by WAXS and SAXS methods and electron microscopy. It has been demonstrated that the addition of modifiers and further thermal treatment under conventional curing conditions change considerably the microheterogeneous structure and morphology and contribute to the improvement of the short-range order in the rubber matrix.  相似文献   
8.
Published data on the preparation procedures, stability, and complexation of U(III) in aqueous solutions are summarized and correlated. Reactions with inorganic and organic free radicals studied by the flash radiolysis method, the spectroscopic properties, the extraction and ion-exchange behavior of U(III), and methods for isolation of solid U(III) compounds from aqueous solutions are discussed.  相似文献   
9.
Gonadotropin-releasing hormone (GnRH) molecular variants in the brain and pituitary gland of pejerrey, Odontesthes bonariensis (Atheriniformes), were characterized by gradient reverse phase high performance liquid chromatography (RP-HPLC). Eluted fractions were tested in radioimmunoassays with different antisera. The results show that the brain extract contains three forms of GnRH: one is immunologically and chromatographically similar to cIIGnRH (chicken II), and another is similar to sGnRH (salmon). A third GnRH appears to be chromatographic and immunologically different from the nine other known forms of the vertebrate hormone. This is the only variant present in the pituitary gland.  相似文献   
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