全文获取类型
收费全文 | 1101285篇 |
免费 | 121261篇 |
国内免费 | 1250篇 |
专业分类
1223796篇 |
出版年
2018年 | 10291篇 |
2017年 | 9662篇 |
2016年 | 14073篇 |
2015年 | 19645篇 |
2014年 | 22962篇 |
2013年 | 32276篇 |
2012年 | 36569篇 |
2011年 | 37228篇 |
2010年 | 25246篇 |
2009年 | 23037篇 |
2008年 | 32875篇 |
2007年 | 33823篇 |
2006年 | 31897篇 |
2005年 | 30648篇 |
2004年 | 30564篇 |
2003年 | 29155篇 |
2002年 | 28301篇 |
2001年 | 48376篇 |
2000年 | 48423篇 |
1999年 | 38770篇 |
1998年 | 14324篇 |
1997年 | 14607篇 |
1996年 | 13840篇 |
1995年 | 13024篇 |
1994年 | 12558篇 |
1993年 | 12437篇 |
1992年 | 32159篇 |
1991年 | 31381篇 |
1990年 | 30599篇 |
1989年 | 29768篇 |
1988年 | 27707篇 |
1987年 | 26099篇 |
1986年 | 24332篇 |
1985年 | 24236篇 |
1984年 | 20161篇 |
1983年 | 17196篇 |
1982年 | 13102篇 |
1981年 | 11803篇 |
1980年 | 10949篇 |
1979年 | 18607篇 |
1978年 | 14712篇 |
1977年 | 13186篇 |
1976年 | 12192篇 |
1975年 | 13713篇 |
1974年 | 14742篇 |
1973年 | 14593篇 |
1972年 | 13051篇 |
1971年 | 11979篇 |
1970年 | 10242篇 |
1969年 | 9929篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
221.
L S Katkova 《Biulleten' eksperimental'no? biologii i meditsiny》1985,99(4):413-415
Extensibility, contractile function and resistance to excess calcium of the right atrium myocardium were studied in normotensive Wistar-Kyoto and August rats and in spontaneously hypertensive rats (SHR). It was shown that long-term stress results in a decrease in the measured parameters in normotensive animals. SHR do not show any stress-induced disturbances. It was discovered that in intact SHR rats, the myocardium has a greater resistance to excess calcium, indirect evidence for higher efficiency of the Ca-pump of the sarcoplasmic reticulum in cardiomyocytes of SHR animals, which is apparently a constituent part of the mechanism of such animals' heart increased resistance to stress-induced damage. 相似文献
222.
THE TIMING OF DIVISION IN CHLAMYDOMONAS 总被引:3,自引:2,他引:1
223.
A L Nevmiatullin O N Vorob'eva A N Maianski? 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1985,(7):67-71
The neutrophil-stimulating properties of 38 S. aureus strains and 32 S. epidermidis strains were studied in the reaction of luminol-mediated chemiluminescence. All S. aureus strains and 29 S. epidermidis strains were found to possess neutrophil-stimulating activity, the mean activity index for S. aureus being significantly higher. The stimulating activity of the strains varied within a wide range (the variation coefficient was 120.0 +/- 21.9%) and did not correlate with the content of protein A in bacterial cells and the degree of their hydrophoby. The opsonization of staphylococci with normal human serum enhanced the neutrophil reaction 1.5- to 100-fold and simultaneously leveled out the chemiluminescence indices in experiments with different strains (the variation coefficient was 8.0 +/- 1.5%). The nature of the neutrophil-stimulating effect of staphylococci and its relationship to the exploratory reactions of phagocytes are discussed. 相似文献
224.
225.
J E Pugh M R Horwitz D J Anderson E F Singleton 《American journal of physical anthropology》1973,38(2):351-356
A new technique for the continuous recording of peripheral bioelectrical activity in the auditory system of primates is described. Because of basic differences in the anatomy of the temporal bone, the approach to the round window of the cochlea is more difficult in most primates than in lower animals. A relatively simple surgical approach, which made possible the placement of an electrode into the perilymph of the inner ear via the well-demarcated horizontal semicircular canal was therefore developed and is described in detail. The bared tip of a Teflon-coated wire was cemented into the canal opening with carboxylate cement, and the wire attached to a permanent electrical connector on the skull. Cochlear microphonic and action potentials of 50 to 100 μV amplitude were thus recorded on a continuing basis at the same time that behavioral studies of primate auditory acuity were conducted. 相似文献
226.
227.
228.
229.
230.