全文获取类型
收费全文 | 20352篇 |
免费 | 1893篇 |
国内免费 | 12篇 |
出版年
2023年 | 102篇 |
2022年 | 270篇 |
2021年 | 564篇 |
2020年 | 267篇 |
2019年 | 390篇 |
2018年 | 435篇 |
2017年 | 340篇 |
2016年 | 586篇 |
2015年 | 985篇 |
2014年 | 1020篇 |
2013年 | 1399篇 |
2012年 | 1597篇 |
2011年 | 1565篇 |
2010年 | 967篇 |
2009年 | 844篇 |
2008年 | 1212篇 |
2007年 | 1192篇 |
2006年 | 1073篇 |
2005年 | 1015篇 |
2004年 | 914篇 |
2003年 | 853篇 |
2002年 | 823篇 |
2001年 | 198篇 |
2000年 | 153篇 |
1999年 | 180篇 |
1998年 | 169篇 |
1997年 | 141篇 |
1996年 | 117篇 |
1995年 | 111篇 |
1994年 | 117篇 |
1993年 | 112篇 |
1992年 | 120篇 |
1991年 | 107篇 |
1990年 | 98篇 |
1989年 | 85篇 |
1988年 | 93篇 |
1987年 | 72篇 |
1986年 | 66篇 |
1985年 | 89篇 |
1984年 | 96篇 |
1983年 | 62篇 |
1982年 | 81篇 |
1981年 | 72篇 |
1980年 | 67篇 |
1979年 | 77篇 |
1978年 | 54篇 |
1977年 | 61篇 |
1976年 | 67篇 |
1975年 | 70篇 |
1973年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
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
943.
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
944.
945.
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
946.
947.
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
948.
Samarina Lidiia Gvasaliya Maya Koninskaya Natalia Rakhmangulov Ruslan Efremov Alexander Kiselyova Natalia Ryndin Alexey Hanke Magda-Viola 《Plant Cell, Tissue and Organ Culture》2019,136(3):467-478
Plant Cell, Tissue and Organ Culture (PCTOC) - The development of tissue-specific or inducible promoters is important for plant genetic engineering. In this study, we isolated two novel promoters... 相似文献
949.
Alexander D. M. Wilson Clint D. Kelly 《Ethology : formerly Zeitschrift fur Tierpsychologie》2019,125(6):380-391
In many animal species, variation in reproductive success among individuals has led to the evolution of alternative mating strategies, which in the case of insects can often be correlated with developmental trajectories. In the Wellington tree weta, Hemideina crassidens, males can mature at the 8th, 9th or 10th instar, while females mature at the 10th instar only. A number of morphological attributes including male head and mandible size correlate with final instar number, and as these attributes represent a form of weaponry, they are often used in mate/site guarding and male–male competition. Tenth instar males have larger head/mandible/body sizes and show a conventional (guarder) reproductive strategy, whereas smaller 8th instar males typically show an unconventional (sneaker) strategy. In contrast, 9th instar males are predicted to adopt a “jack‐of‐all‐trades” strategy whereby they can fight or sneak depending context. Here, we tested whether alternative reproductive morphs exhibit strategy‐specific differences in risk‐taking associated with refuge emergence, activity and antipredator behaviour and further, whether these traits correlate to form a behavioural syndrome. We found that tree weta show consistent and repeatable differences in activity and refuge use at the individual level; however, behavioural covariances suggest that only 8th instar males exhibit a behavioural syndrome. That 9th instar males show high plasticity and variance in their gallery‐related behaviours supports the hypothesis that these males are a “jack‐of‐all‐trades.” Contrary to our predictions, antipredator behaviour was not correlated with other traits, and differences in behaviour overall were consistently more pronounced between individuals rather than between male morphs or sexes. 相似文献
950.
Lange Alexander Schwieger Robert Plöntzke Julia Schäfer Stefan Röblitz Susanna 《Journal of mathematical biology》2019,78(3):579-606
Journal of Mathematical Biology - The reproductive cycle of mono-ovulatory species such as cows or humans is known to show two or more waves of follicular growth and decline between two successive... 相似文献