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   3023篇
  免费   334篇
  国内免费   3篇
  2021年   26篇
  2019年   28篇
  2018年   28篇
  2017年   27篇
  2016年   62篇
  2015年   84篇
  2014年   100篇
  2013年   139篇
  2012年   139篇
  2011年   146篇
  2010年   95篇
  2009年   104篇
  2008年   131篇
  2007年   125篇
  2006年   149篇
  2005年   141篇
  2004年   129篇
  2003年   117篇
  2002年   111篇
  2001年   53篇
  2000年   34篇
  1999年   55篇
  1998年   41篇
  1997年   34篇
  1996年   40篇
  1995年   51篇
  1994年   52篇
  1993年   53篇
  1992年   63篇
  1991年   49篇
  1990年   46篇
  1989年   46篇
  1988年   35篇
  1987年   42篇
  1986年   54篇
  1985年   60篇
  1984年   50篇
  1983年   28篇
  1982年   31篇
  1981年   35篇
  1980年   24篇
  1979年   43篇
  1978年   29篇
  1977年   24篇
  1976年   27篇
  1975年   20篇
  1974年   24篇
  1973年   25篇
  1970年   33篇
  1968年   19篇
排序方式: 共有3360条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
66.
Summary A new case of triploid-diploid mosaicism in the lymphocytes of a newborn with multiple malformations is reported, and the origin of the mosaicism is briefly discussed.N.I.H. International Post-doctoral Fellow.Bevoegd Navorser N.F.W.O.  相似文献   
67.
Spray-fogging of hospital rooms with a quarternary ammonium disinfectant was found to be an effective means of reducing the number of detectable airborne and surface bacteria. The level of bacterial contamination in hospital rooms was determined before and after fogging by means of the gravitational fallout method, the petri dish swab technique, and volumetric air-sampling procedures. Rooms vacated by patients infected with staphylococci, streptococci, pseudomonads, and salmonellae were tested and found to be effectively decontaminated of most of the detectable organisms by the fogging procedure.  相似文献   
68.
Staphylococcal Hyaluronate Lyase: Purification and Characterization Studies   总被引:5,自引:1,他引:4  
Staphylococcal hyaluronate lyase (hyaluronidase) derived from a pathogenic strain of staphylococcus was purified by means of salt fractionation with ammonium sulfate and gel filtration through Sephadex G-100. Most of the enzyme activity from concentrated culture supernatant fluids of staphylococci was obtained in a fraction precipitated by 90 to 100% saturation with ammonium sulfate. A small amount of enzyme was also precipitated by 80 to 90% saturation with the salt. The hyaluronidase-rich fractions did not contain other staphylococcal enzymes, such as coagulase, protease, lipase, and staphylokinase. These enzymes were present in the original concentrates. Molecular sieving chromatography of the partially purified enzyme by filtration through Sephadex G-100 resulted in a further increase in specific enzyme activity. However, more than one active peak was obtained after gel filtration, thus suggesting that there may be more than one molecular form of the enzyme. Immunodiffusion in agar gel of the chromatographically purified enzyme fraction, with immune serum from rabbits injected with concentrated staphylococcal culture supernatant fluids, indicated that there was one major antigen. A similar antigen, giving reactions of identity with the purified material, was present in the original culture supernatant fluid.  相似文献   
69.
Studies on renal aldosterone-binding proteins   总被引:9,自引:0,他引:9  
  相似文献   
70.
The electrical properties of the pleuropneumonia-like organism A 5969 have been determined over the frequency range from 0.5 to 250 Mcps. The frequency dependence of the dielectric constant and conductivity of PPLO suspensions is completely consistent with the existence of a membrane. The PPLO has an internal conductance which in part reflects its ionic equilibrium with normal nutrient and macromolecular constituents. But it is fairly independent from variation in external ionic strength.  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