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   316篇
  免费   21篇
  2021年   7篇
  2020年   4篇
  2018年   4篇
  2016年   5篇
  2015年   9篇
  2014年   9篇
  2013年   14篇
  2012年   13篇
  2011年   14篇
  2010年   9篇
  2009年   8篇
  2008年   16篇
  2007年   11篇
  2006年   17篇
  2005年   9篇
  2004年   7篇
  2003年   14篇
  2002年   8篇
  2001年   6篇
  2000年   7篇
  1999年   3篇
  1998年   3篇
  1996年   2篇
  1993年   2篇
  1992年   5篇
  1991年   6篇
  1990年   8篇
  1989年   4篇
  1988年   8篇
  1986年   7篇
  1985年   4篇
  1984年   6篇
  1982年   6篇
  1981年   5篇
  1980年   2篇
  1979年   4篇
  1978年   7篇
  1977年   6篇
  1976年   7篇
  1975年   6篇
  1974年   7篇
  1973年   4篇
  1972年   5篇
  1971年   4篇
  1970年   2篇
  1968年   2篇
  1965年   2篇
  1950年   2篇
  1942年   2篇
  1934年   2篇
排序方式: 共有337条查询结果,搜索用时 15 毫秒
1.
H Bohn 《Blut》1971,22(5):237-243
  相似文献   
2.
H Haupt  H Bohn 《Blut》1977,35(3):229-239
A new protein was isolated from lysates of washed human erythrocytes in a two step procedure using ionexchange chromatography and gel filtration. The protein has the electrophoretic mobility of a beta1-globulin. On ultracentrifugation the purified protein when dissolved in a 0.05 M phosphate buffer (pH 6.8), containing 0.2 M NaCl sediments with 6.88 S and shows a molecular weight of 150,000-180,000 daltons. In salt solutions with higher ionic strength the molecules dissociate reversibly into subunits which have a molecular weight of 40,000-45,000 daltons. The 7S-beta1-erythrocyte protein according to its behavior at ultracentrifugation, gel filtration and SDS poly-acrylamide gel electrophreses apparently is composed of 4 identical or similar subunits which are loosely held together by noncovalent bonds. Chemically the 7S-beta1-erythrocyte protein consists of 99% amino acids and 1% carbohydrates. The concentration of this protein in erythrocytes amounts to 250 mg per 100 ml packed red blood cells. The protein is not found in the membrane. In its physical, chemical and immunochemical properties the 7S-beta1-erythrocyte protein differs from all other well defined proteins and enzymes from human red cells thus far known.  相似文献   
3.
4.
5.
6.
This experiment was conducted with the objective of demonstrating that the effective stimuli in Pavlovian Conditioning are not environmental stimuli but internal physiological processes elicited by environmental input (proximal stimuli). In order to achieve the objective, afterimages in color vision were used: looking at a diffuse lightened circle after seeing a red circle yields an image of a green circle. A differential conditioning paradigm with two sequential compounds was run. In one group (G+B-: n1 = 10), a red circle followed by a green circle was paired with shock, whereas a red circle followed by a blue circle remained unpaired. A second group (G-B+: n2 = 10) received red-blue paired trials and unpaired red-green trials. Immediately after that training, subjects were tested with a new, never trained sequential compound: a red circle followed by a diffuse lightened circle. Furthermore, they were tested with the already trained compounds. Taking the environmental point of view, the never trained stimulus should elicit an orienting response lying in between the excitatory reaction to the paired stimulus and the inhibitory reaction to the unpaired stimulus. From the proximal point of view, the diffuse light should elicit an excitatory reaction in group G+B- and an inhibitory reaction in group G-B+. Electrodermal conditioned anticipatory and omission responses were measured. The results supported the proximal hypothesis. Hence, defining input in environmental terms may be the wrong way. Instead, in conceptualizing the stimulus in conditioning, the following should be considered: the processing organism itself is creating the effective stimuli.  相似文献   
7.
8.
9.
Genetic chemotyping is an essential tool for characterizing Fusarium populations causing head blight on wheat and other cereals. Three PCR methods, based on tri cluster polymorphism, were optimized and compared on 94 single‐spore isolates obtained from three continents belonging to F. gramineaurm, F. culmorum, F. poae, F. avenaceum and Microdochium nivale. While the methods based on the tri3, tri7 and tri12 polymorphism correctly identified all the tested strains, the method based on tri13 polymorphism was unable to discriminate between the 3‐ and 15‐acetylated DON forms in F. graminearum. It is advised to avoid the use of tri13 polymorphism for genetic chemotyping of the two acetylated chemotypes.  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