全文获取类型
收费全文 | 20406篇 |
免费 | 1895篇 |
国内免费 | 12篇 |
出版年
2023年 | 102篇 |
2022年 | 270篇 |
2021年 | 563篇 |
2020年 | 266篇 |
2019年 | 388篇 |
2018年 | 437篇 |
2017年 | 342篇 |
2016年 | 586篇 |
2015年 | 985篇 |
2014年 | 1021篇 |
2013年 | 1401篇 |
2012年 | 1602篇 |
2011年 | 1571篇 |
2010年 | 969篇 |
2009年 | 846篇 |
2008年 | 1215篇 |
2007年 | 1206篇 |
2006年 | 1081篇 |
2005年 | 1019篇 |
2004年 | 918篇 |
2003年 | 857篇 |
2002年 | 823篇 |
2001年 | 198篇 |
2000年 | 154篇 |
1999年 | 182篇 |
1998年 | 168篇 |
1997年 | 140篇 |
1996年 | 116篇 |
1995年 | 110篇 |
1994年 | 116篇 |
1993年 | 113篇 |
1992年 | 121篇 |
1991年 | 107篇 |
1990年 | 98篇 |
1989年 | 85篇 |
1988年 | 96篇 |
1987年 | 72篇 |
1986年 | 66篇 |
1985年 | 89篇 |
1984年 | 96篇 |
1983年 | 63篇 |
1982年 | 81篇 |
1981年 | 72篇 |
1980年 | 67篇 |
1979年 | 78篇 |
1978年 | 54篇 |
1977年 | 60篇 |
1976年 | 66篇 |
1975年 | 70篇 |
1973年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
941.
Austin J. Gallagher Michael J. Lawrence Sofia M. R. Jain-Schlaepfer Kathleen M. Gilmour Alexander D. M. Wilson Steven J. Cooke 《Journal of fish biology》2019,95(3):969-973
We compared baseline and maximal cortisol concentrations between predator exposure and prey blood samples in pumpkinseed Lepomis gibbosus, captured using a standardised fishing event underneath osprey Pandion haliaetus nests and away from osprey nests. We did not detect differences in cortisol or glucose between sites. These findings suggest that predictable sources of predation risk may not confer stress-related costs in teleosts. 相似文献
942.
943.
Alexander S. Kashin Tatyana A. Kritskaya Alena S. Parkhomenko Ivan A. Schanzer 《Nordic Journal of Botany》2019,37(11)
We studied genetic diversity in 54 populations of nine sexual and apomictic species of the genus Chondrilla (C. acantholepis, C. ambigua, C. brevirostris, C. canescens, C. graminea, C. juncea, C. laticoronata, C. latifolia and C. pauciflora) in SE European Russia and neighboring territories of NW Kazakhstan. We analysed the trnT–trnF region of plastid DNA and the internal transcribed spacer of ribosomal DNA (ITS1–5.8S–ITS2) using statistical parsimony, maximum likelihood and neighbor net methods. Two major evolutionary lineages, roughly corresponding to the two subgenera traditionally recognized in the region, were revealed. Within the first evolutionary lineage (subgenus Brachyrhynchus), the sexual diploid C. ambigua and its putatively hybrid apomictic derivatives C. brevirostris, C. laticoronata and C. pauciflora could be recognized. Their identity was also confirmed by analyses of ISSR markers. The second evolutionary lineage (subgenus Chondrilla) comprises C. juncea, C. acantholepis, C. canescens, C. graminea and C. latifolia in European Russia, but analyses of morphological variability and the genealogy of plastid and nuclear markers favor their treatment as the single facultatively apomictic species C. juncea. The results demonstrate that an apomictic mode of reproduction does not necessarily result in the formation of genetically separated microspecies. 相似文献
944.
945.
Asprouli Eleni Kalafati Ioanna Panagiota Sakellari Aikaterini Karavoltsos Sotirios Vlachogiannakos John Revenas Konstantinos Kokkinos Alexander Dassenakis Manos Dedoussis George V. Kalogeropoulos Nick 《Biological trace element research》2019,188(2):326-333
Biological Trace Element Research - Nonalcoholic fatty liver disease (NAFLD) is considered as the hepatic manifestation of metabolic syndrome. Its global prevalence is estimated between 25 and 45%,... 相似文献
946.
Casartelli Alberto Melino Vanessa J. Baumann Ute Riboni Matteo Suchecki Radoslaw Jayasinghe Nirupama S. Mendis Himasha Watanabe Mutsumi Erban Alexander Zuther Ellen Hoefgen Rainer Roessner Ute Okamoto Mamoru Heuer Sigrid 《Plant molecular biology》2019,99(4-5):477-497
Plant Molecular Biology - Degradation of nitrogen-rich purines is tightly and oppositely regulated under drought and low nitrogen supply in bread wheat. Allantoin is a key target metabolite for... 相似文献
947.
948.
Kalmatskaya Olesya A. Karavaev Vladimir A. Tikhonov Alexander N. 《Photosynthesis research》2019,142(3):265-282
Photosynthesis Research - Tradescantia is a good model for assaying induction events in higher plant leaves. Chlorophyll (Chl) fluorescence serves as a sensitive reporter of the functional state of... 相似文献
949.
950.
Betekhtin Alexander Pinski Artur Milewska-Hendel Anna Kurczynska Ewa Hasterok Robert 《Plant Cell, Tissue and Organ Culture》2019,137(2):343-357
Plant Cell, Tissue and Organ Culture (PCTOC) - The morphogenic callus (MC) of Fagopyrum tataricum contains a large amount of flavonoids, especially rutin, and exhibits a high level of antioxidant... 相似文献