全文获取类型
收费全文 | 2599篇 |
免费 | 254篇 |
出版年
2023年 | 21篇 |
2022年 | 52篇 |
2021年 | 96篇 |
2020年 | 49篇 |
2019年 | 60篇 |
2018年 | 68篇 |
2017年 | 54篇 |
2016年 | 98篇 |
2015年 | 187篇 |
2014年 | 185篇 |
2013年 | 186篇 |
2012年 | 240篇 |
2011年 | 214篇 |
2010年 | 136篇 |
2009年 | 114篇 |
2008年 | 149篇 |
2007年 | 137篇 |
2006年 | 110篇 |
2005年 | 109篇 |
2004年 | 108篇 |
2003年 | 91篇 |
2002年 | 84篇 |
2001年 | 20篇 |
2000年 | 19篇 |
1999年 | 16篇 |
1998年 | 15篇 |
1997年 | 18篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1979年 | 5篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1972年 | 4篇 |
1971年 | 7篇 |
1970年 | 4篇 |
1969年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有2853条查询结果,搜索用时 15 毫秒
41.
Katharine N. Savage Kathy Burek-Huntington Sadie K. Wright Anna L. Bryan Gay Sheffield Marc Webber Raphaela Stimmelmayr Pam Tuomi Martha A. Delaney William Walker 《Marine Mammal Science》2021,37(3):843-869
Presented here is the first comprehensive and updated compilation of history, distribution, and findings of Stejneger's beaked whales (Mesoplodon stejnegeri) in Alaska. Stejneger's beaked whales are a poorly understood, elusive, deep-diving cetacean species found in the North Pacific Ocean. Since Stejneger's beaked whale strandings data in Alaska through 1994 were last published, 35 additional strandings have been documented. Twenty-seven animals stranded in the Aleutian Islands, seven stranded in Southcentral Alaska, and one animal stranded on St. Lawrence Island. Twenty-two carcasses were necropsied, but only four were fresh. Seventeen of the 22 died during mass stranding events and cause of death could not be definitively determined. Barotrauma was suspected in three cases and infectious disease possibly complicated by barotrauma occurred in two cases. We documented an expansion of strandings into the northern Bering Sea, characterized a sex bias, examined stomach contents that included macroplastic, and identified parasites not previously associated with Stejneger's beaked whales. Also included are data on the largest known mass stranding of Stejneger's beaked whales, which occurred on Adak Island in 2018. The history, distribution, and findings presented here are central to further our understanding of this species. 相似文献
42.
43.
44.
Natalie V. Klinard Jordan K. Matley Silviya V. Ivanova Sarah M. Larocque Aaron T. Fisk Timothy B. Johnson 《Journal of fish biology》2021,98(1):237-250
Understanding predator–prey interactions and food web dynamics is important for ecosystem-based management in aquatic environments, as they experience increasing rates of human-induced changes, such as the addition and removal of fishes. To quantify the post-stocking survival and predation of a prey fish in Lake Ontario, 48 bloater Coregonus hoyi were tagged with acoustic telemetry predation tags and were tracked on an array of 105 acoustic receivers from November 2018 to June 2019. Putative predators of tagged bloater were identified by comparing movement patterns of six species of salmonids (i.e., predators) in Lake Ontario with the post-predated movements of bloater (i.e., prey) using a random forests algorithm, a type of supervised machine learning. A total of 25 bloater (53% of all detected) were consumed by predators on average (± S.D. ) 3.1 ± 2.1 days after release. Post-predation detections of predators occurred for an average (± S.D. ) of 78.9 ± 76.9 days, providing sufficient detection data to classify movement patterns. Tagged lake trout Salvelinus namaycush provided the most reliable classification from behavioural predictor variables (89% success rate) and was identified as the main consumer of bloater (consumed 50%). Movement networks between predicted and tagged lake trout were significantly correlated over a 6 month period, supporting the classification of lake trout as a common bloater predator. This study demonstrated the ability of supervised learning techniques to provide greater insight into the fate of stocked fishes and predator–prey dynamics, and this technique is widely applicable to inform future stocking and other management efforts. 相似文献
45.
Dybzinski Ray Taylor Natalie Prosser Megan Niosi Olivia Demo Madeline Kilbane Erin 《Plant Ecology》2021,222(8):977-991
Plant Ecology - Understanding resource uptake as a function of fine-root mass is important for both basic ecological theory and applied biogeochemical cycling models. We measured plant population... 相似文献
46.
John A. Terrizzi Natalie J. Shook Michael A. McDaniel 《Evolution and human behavior》2013,34(2):99-108
The behavioral immune system (BIS) is a cluster of psychological mechanisms (e.g., disgust) that have evolved to promote disease-avoidance (Schaller M. (2006). Parasites, behavioral defenses, and the social psychological mechanisms through which cultures are evoked. Psychological Inquiry, 17, 96–101). Recent evidence suggests that the BIS may promote avoidance of outgroup members, an historical source of contamination, by evoking social conservatism (Terrizzi JA Jr, Shook NJ, & Ventis WL. (2010). Disgust: A predictor of social conservatism and prejudicial attitudes toward homosexuals. Personality and Individual Differences, 49, 587–592; Terrizzi J, Shook N, Ventis L. (2012). Religious conservatism: An evolutionarily evoked disease-avoidance strategy. Religion, Brain & Behavior, 2, 105–120.). That is, the BIS mechanisms may encourage the endorsement of socially conservative beliefs, which promote social exclusivity, tradition, and negativity toward outgroups. The current study provides a systematic review and meta-analysis of 24 studies to evaluate the hypothesis that the BIS is predictive of social conservatism. The results indicate that behavioral immune strength, as indicated by fear of contamination and disgust sensitivity, is positively related to social conservatism (i.e., right-wing authoritarianism, social dominance orientation, religious fundamentalism, ethnocentrism, collectivism, and political conservatism). These findings provide initial evidence that socially conservative values may function as evolutionarily evoked disease-avoidance strategies. 相似文献
47.
Varintip Srinon Sunsiree Muangman Nithima Imyaem Veerachat Muangsombut Natalie R. Lazar Adler Edouard E. Galyov Sunee Korbsrisate 《Journal of microbiology (Seoul, Korea)》2013,51(4):522-526
Burkholderia pseudomallei, the causative agent of melioidosis, is a Gram-negative saprophytic bacterium capable of surviving within phagocytic cells. To assess the role of BopC (a type III secreted effector protein) in the pathogenesis of B. pseudomallei, a B. pseudomallei bopC mutant was used to infect J774A.1 macrophage-like cells. The bopC mutant showed significantly reduced intracellular survival in infected macrophages compared to wild-type B. pseudomallei. In addition, the bopC mutant displayed delayed escape from endocytic vesicles compared with the wild-type strain. This indicates that BopC is important, and at least in part, needed for intracellular survival of B. pseudomallei. 相似文献
48.
49.
Florian Wilfling Huajin Wang Joel T. Haas Natalie Krahmer Travis J. Gould Aki Uchida Ji-Xin Cheng Morven Graham Romain Christiano Florian Fröhlich Xinran Liu Kimberly K. Buhman Rosalind A. Coleman Joerg Bewersdorf Robert V. Farese Tobias C. Walther 《Developmental cell》2013,24(4):384-399
- Download : Download high-res image (442KB)
- Download : Download full-size image
50.