全文获取类型
收费全文 | 30353篇 |
免费 | 1418篇 |
国内免费 | 6篇 |
出版年
2023年 | 170篇 |
2022年 | 213篇 |
2021年 | 568篇 |
2020年 | 433篇 |
2019年 | 525篇 |
2018年 | 874篇 |
2017年 | 760篇 |
2016年 | 1030篇 |
2015年 | 1186篇 |
2014年 | 1395篇 |
2013年 | 1852篇 |
2012年 | 1780篇 |
2011年 | 1888篇 |
2010年 | 1175篇 |
2009年 | 951篇 |
2008年 | 1318篇 |
2007年 | 1383篇 |
2006年 | 1367篇 |
2005年 | 1115篇 |
2004年 | 984篇 |
2003年 | 975篇 |
2002年 | 830篇 |
2001年 | 645篇 |
2000年 | 545篇 |
1999年 | 436篇 |
1998年 | 235篇 |
1992年 | 330篇 |
1991年 | 319篇 |
1990年 | 259篇 |
1989年 | 276篇 |
1988年 | 292篇 |
1987年 | 295篇 |
1986年 | 272篇 |
1985年 | 296篇 |
1984年 | 245篇 |
1983年 | 200篇 |
1979年 | 271篇 |
1978年 | 185篇 |
1977年 | 153篇 |
1976年 | 156篇 |
1975年 | 196篇 |
1974年 | 281篇 |
1973年 | 281篇 |
1972年 | 263篇 |
1971年 | 254篇 |
1970年 | 265篇 |
1969年 | 260篇 |
1968年 | 200篇 |
1967年 | 198篇 |
1966年 | 179篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
Dr. Benedykt Fuliński 《Development genes and evolution》1922,51(1):575-586
Ohne Zusammenfassung
Mit 2 Textabbildungen. 相似文献
42.
A robust method for selection of variables with the greatest discriminatory power is presented in the paper. The method deals with the two groups of data problem. An application of the method to some respiratory disease data and comparisons with classical procedures are given, also. 相似文献
43.
W Tymiński E Czestochowska A Hellmann A Kreglewski 《Folia haematologica (Leipzig, Germany : 1928)》1980,107(2):269-272
Coagulation and fibrinolysis were measured in the portal and peripheral circulation in 15 rabbits after ligation of the superior mesenteric artery. It was found that the local coagulation syndrome in the mesenteric region can be recognized by tests in blood samples taken from the peripheral circulation area. 相似文献
44.
Blanco Pablo J. Müller Lucas O. Watanabe Sansuke M. Feijóo Raúl A. 《Biomechanics and modeling in mechanobiology》2020,19(5):1663-1678
Biomechanics and Modeling in Mechanobiology - The goal of this work is to assess the impact of vascular anatomy definition degree in the predictions of blood flow models of the arterial network. To... 相似文献
45.
In chronic renal failure AMP-deaminase operates in the erythrocytes at a much higher velocity than in healthy subjects, with a simultaneous shift from the AMP-adenine-inosine-hypoxanthine pathway (55% and 19%, respectively) to the pathway initiated by AMP-deaminase (45% and 81%, respectively). 相似文献
46.
Chromosome characterization in Acestrorhynchinae and Cynopotaminae (Pisces, Characidae) 总被引:1,自引:0,他引:1
The karyotypes of six species of Acestrorhynchinae ( Acestrorhynchus alus, A. lacustris, Oligosarcus hepsetus, O. jenynsii, O. macrolepis and O. pinloi ) and of one species of Cynopotaminae ( Galeocharax knerii ) were studied. The six Acestrorhynchinae species have 2 n = 50, while Galeocharax knerii has 2 n = 52 chromosomes. Some chromosomal characteristics were detected which permit establishing some karyotypic relationships among the different species investigated. Thus, among the Acestrorhynchinae, the four Oligosarcus species are relatively more related to one another than the two Acestrorhynchus species, at least with respect to the cytogenetic data considered. On the basis of the methods used, no sex chromosome heteromorphism was detected in the species for which a comparative study between male and female specimens was possible. 相似文献
47.
48.
49.
A Soler C García del Río L García-Torres F Vargas A Martín-Andrés C Osorio 《Revista Espanola de Fisiología》1985,41(1):107-116
The effects of changes in arterial pressure and in circulating volume on Plasma Renin Activity (PRA) in the intact rat were compared by two experimental procedures. Gradual volume depletion was induced by intraperitoneal injection of a hyperoncotic polyethyleneglycol solution (PEG) in absence of acute changes in Systolic Arterial Pressure (SAP). SAP was measured in the conscious state by the tail cuff technique. Plasma Protein Concentration (PPC) and Hematocrit (Hct) increases after PEG injection were compared as the index for measuring the Plasma Volume Reduction (PVR). PRA showed a significant (p less than 0.001) linear relationship with PPC, suggesting a direct dependence of renin secretion on volume depletion. Acute changes in the circulating volume were induced by controlled hemorrhages of 5.0, 10.0, 15.0 and 20.0 ml of blood/kg body weight. The increase in PRA showed a significant relationship with the changes in circulating volume, but it did not show any dependence on the changes in Mean Arterial Pressure (MAP). Our results suggest that, in the intact and conscious rat, renin secretion responds to the information from the cardiopulmonary volume receptors rather than to that from the high pressure receptors. 相似文献
50.