全文获取类型
收费全文 | 2025篇 |
免费 | 42篇 |
国内免费 | 1篇 |
出版年
2022年 | 12篇 |
2021年 | 26篇 |
2020年 | 15篇 |
2019年 | 25篇 |
2018年 | 43篇 |
2017年 | 26篇 |
2016年 | 34篇 |
2015年 | 31篇 |
2014年 | 66篇 |
2013年 | 94篇 |
2012年 | 102篇 |
2011年 | 141篇 |
2010年 | 105篇 |
2009年 | 70篇 |
2008年 | 72篇 |
2007年 | 78篇 |
2006年 | 79篇 |
2005年 | 68篇 |
2004年 | 62篇 |
2003年 | 60篇 |
2002年 | 79篇 |
2001年 | 88篇 |
2000年 | 66篇 |
1999年 | 33篇 |
1998年 | 18篇 |
1992年 | 27篇 |
1991年 | 32篇 |
1990年 | 30篇 |
1989年 | 28篇 |
1988年 | 28篇 |
1987年 | 31篇 |
1986年 | 27篇 |
1985年 | 29篇 |
1984年 | 27篇 |
1983年 | 22篇 |
1979年 | 15篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 23篇 |
1974年 | 19篇 |
1973年 | 20篇 |
1972年 | 17篇 |
1971年 | 17篇 |
1970年 | 14篇 |
1968年 | 18篇 |
1967年 | 13篇 |
1966年 | 11篇 |
1965年 | 9篇 |
1952年 | 10篇 |
1951年 | 11篇 |
排序方式: 共有2068条查询结果,搜索用时 15 毫秒
1.
In this paper the recent population changes of the Wild Boar in different European countries is analysed through the study of hunting statistics. A simultaneous increase in numbers is observed throughout the whole area during the period 1965–1975. From 1975 onwards the population stabilizes itself apart from in peripheral areas like Finland. Potentially favourable factors which play a part in this process are discussed and certain reproductive and dispersive characteristics which favour its invasive behaviour are discussed. 相似文献
2.
Using two-dimensional thin-layer chromatography, the effect of serotonin on the yield of thymine dimers and on cleavage of the N-glycosidic bond in the DNA irradiated with ultraviolet (UV) light and X-ray was studied. Bound serotonin was shown to reduce the synthesis of UV-induced thymine dimers but had no effect on the number of X-ray-induced breaks in the N-glycoside bonds in thymidine residues. The data obtained are discussed in terms of the mechanisms of serotonin involvement in the photoprotection of yeast cells from the lethal action of UV and X-ray irradiations. 相似文献
3.
The activity of cAMP-dependent protein kinases, cAMP binding and the spectrum of cAMP-binding proteins in renal papillary cytosol of intact rats and of rats kept on a water-deprived diet for 24 hours were investigated. It was found that the stimulation of protein kinases by 10(-6) M cAMP in the experimental group was significantly higher than in the control one. On DEAE-cellulose chromatography, the position of peaks of the specific cAMP binding corresponded to those of the regulatory cAMP-dependent protein kinases type I and II. Under these conditions, more than 80% of the binding activity in intact animals was localized in peak II, whereas in rats kept on a water-deprived diet over 60% of the binding activity was localized in peak I. The total binding activity of cytosol in experimental animals remained unchanged is compared to intact rats. It is suggested that in renal papilla dehydration is accompanied by the induction of synthesis of regulatory subunits of cAMP-dependent protein kinase type I. 相似文献
4.
Glushakova A. M. Lysak L. V. Kachalkin A. V. Ivanova A. E. Umarova A. B. Abramyan I. A. Ezhelev Z. S. Maksimova I. A. 《Microbiology》2021,90(2):176-186
Microbiology - In a model experiment, the transformation of microbial complexes of cultivated saprotrophic bacteria and yeasts during freezing-thawing was studied in various natural substrates that... 相似文献
5.
6.
E A Ivanova 《Ontogenez》1987,18(3):320-323
The influence of testosterone on the rate of total protein synthesis in the reproductive tract tissues and muscles was studied in the guinea pig male embryos from 26 days of development until birth. The rate of protein synthesis was estimated by the intensity of 3H-leucine incorporation per 1 mg protein for 30 min. Testosterone increased the rate of protein synthesis at all studies stages. A higher rate of protein synthesis was revealed at the stages of active morphogenesis and growth of rudiments and organs of genital system and correlated with their ability of 3H-testosterone uptake (Ivanova, 1982). 相似文献
7.
R Kh Iafaev V V Dudareva T G Ivanova E B Kaganer L V Loseva 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1986,(11):16-20
The short-term prognosis of the epidemic situation requires the establishment of the system of constant surveillance, which takes into account the data on morbidity rates for several years, both total and in various age groups, the data on the morbidity level and its changes, induced by meningococci of the epidemic group, in the IV quarter of the year, the data on the level of carriership among the indicator groups of the population in this period, as well as the data on changes in antibody titers in the sera of donor blood samples taken in summer and in December. 相似文献
8.
9.
10.
In the study of P. aeruginosa cultures, serogroup O11, strains agglutinated simultaneously by factor sera 11b and 11c have been detected. In experiments on cross agglutination and agglutinin adsorption the antigenic structure of these strains, viz. 11a, 11b and 11c, has been determined. 相似文献