全文获取类型
收费全文 | 11142篇 |
免费 | 18篇 |
国内免费 | 35篇 |
专业分类
系统科学 | 41篇 |
丛书文集 | 205篇 |
教育与普及 | 39篇 |
理论与方法论 | 50篇 |
现状及发展 | 5184篇 |
研究方法 | 494篇 |
综合类 | 5049篇 |
自然研究 | 133篇 |
出版年
2013年 | 97篇 |
2012年 | 167篇 |
2011年 | 300篇 |
2010年 | 67篇 |
2008年 | 193篇 |
2007年 | 209篇 |
2006年 | 204篇 |
2005年 | 230篇 |
2004年 | 188篇 |
2003年 | 192篇 |
2002年 | 201篇 |
2001年 | 287篇 |
2000年 | 296篇 |
1999年 | 189篇 |
1992年 | 177篇 |
1991年 | 150篇 |
1990年 | 153篇 |
1989年 | 158篇 |
1988年 | 165篇 |
1987年 | 157篇 |
1986年 | 170篇 |
1985年 | 232篇 |
1984年 | 140篇 |
1983年 | 140篇 |
1982年 | 98篇 |
1981年 | 117篇 |
1980年 | 150篇 |
1979年 | 377篇 |
1978年 | 282篇 |
1977年 | 304篇 |
1976年 | 219篇 |
1975年 | 220篇 |
1974年 | 341篇 |
1973年 | 280篇 |
1972年 | 299篇 |
1971年 | 308篇 |
1970年 | 420篇 |
1969年 | 364篇 |
1968年 | 365篇 |
1967年 | 334篇 |
1966年 | 292篇 |
1965年 | 213篇 |
1964年 | 69篇 |
1959年 | 117篇 |
1958年 | 211篇 |
1957年 | 169篇 |
1956年 | 160篇 |
1955年 | 132篇 |
1954年 | 132篇 |
1948年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
411.
J. Teisinger F. Vyskočil Hana Dlouhá 《Cellular and molecular life sciences : CMLS》1981,37(4):383-384
Summary The activity of the membrane ATPase of 5 organs of the golden hamster was increased by 10–7–10–3 moles/l ouabain in K+-free medium. In similar experiments on rats no increase was observed. 相似文献
412.
Summary Chronic catheterization of aorta and inferior vena cava in dogs did not significantly affect circulating levels of prostaglandins (PGE2 and PGF2a
). Pentobarbital (30 mg/kg i.v.) anaesthesia produced a significant decrease in PGF2a
.This work was supported by INSERM (grant No. 76.5.183.5).We wish to thank Miss Laure Eloy and Mrs Annick Soubrier for their technical assistance. 相似文献
413.
R F Laguzzi J Adrien 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1977,285(10):1061-1063
Intraventricular injection of 6-hydroxydopamine does not modify the states of alertness in the Kitten, if it is performed in the first week of postnatal life. At three weeks of age, it induces the same sleep impairments as those observed in the adult Cat. Therefore, in the immediate postnatal period, sleep control is not achieved through the monoaminergic systems. 相似文献
414.
D Gerlier F Sakai J F Doré 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(5):439-442
The Gross virus associated cell surface antigen GCSAa was extracted from (C58NT)D cells by solubilization of membranes with detergent and partially purified. This antigen was entraped in liposomes. Absorption experiments of the cytotoxic activity towards EmaleG2 cells of a W/Fu anti (C58NT)D serum showed the presence of the antigen at the surface of sensibilized liposomes. 相似文献
415.
K. Silberbauer H. Sinzinger Maya Winter W. Feigl F. Ring 《Cellular and molecular life sciences : CMLS》1978,34(11):1471-1472
Summary Morphological control of Moncada's bioassay for prostacyclin (PG I2) activity measurement shows that the activity depends not only on endothelium, but in important amounts on subendothelial tissue too. Therefore, it can be concluded that platelet thrombus formation after endothelial cell injury does not depend only on the PG I2-producing ability of the tissue. 相似文献
416.
Summary I.v. botulinum toxin after 60–90 min abolished the dose-response relationship between pentagastrin and gastric acid secretion in anesthetized rats and guinea-pigs. The toxin reduced but did not abolish the acid stimulatory effect of histamine. As expected, the acid response to vagal stimulation was abolished and that to methacholine in rats was unaltered by the toxin.Acknowledgment. We are grateful to the generosity of Dr Edward J. Schantz, Food Research Institute, University of Wisconsin, for the botulinum toxin used. — This research was supported by NIH grant 1 RO1 AM 17125, The Secretion of Pepsin. 相似文献
417.
The human B cell-specific alloantigen which is closely linked genetically to HLA contains two non-covalently associated, sialogycoprotein subunits of molecular weight (MW) 29,000 (p29), and 34,000 (p34). Although p29 and p34 have different amino-terminal sequences, their tyrosine peptide maps indicate considerable similarity in other portions of their polypeptide chains. Thus the genes for their proteins may have evolved by duplication of a common ancestral gene. Another lymphocyte cell surface protein of MW 16,000 (p16) has also been characterised. Both p16 and p44 (the heavy chain of HLA-A,B antigens) have been compared with p29 and p34. 相似文献
418.
419.
420.
Three variable-gene pools common to IgM, IgG and IgA immunoglobulins 总被引:12,自引:0,他引:12