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71.
Hammock Bruce G. Hartman Rosemary Dahlgren Randy A. Johnston Catherine Kurobe Tomofumi Lehman Peggy W. Lewis Levi S. Van Nieuwenhuyse Erwin Ramrez-Duarte Wilson F. Schultz Andrew A. Teh Swee J. 《Hydrobiologia》2022,849(3):675-695
Hydrobiologia - Condition indices are key predictors of health and fitness in wild fish populations. Variation in body condition, therefore, can be used to identify stressful conditions that may... 相似文献
72.
Foraging habits in a generalist predator: Sex and age influence habitat selection and resource use among bottlenose dolphins (Tursiops truncatus) 下载免费PDF全文
Sam Rossman Elizabeth Berens McCabe Hasand Gandhi Peggy H. Ostrom Craig A. Stricker Randall S. Wells 《Marine Mammal Science》2015,31(1):155-168
This study examines resource use (diet, habitat use, and trophic level) within and among demographic groups (males, females, and juveniles) of bottlenose dolphins (Tursiops truncatus). We analyzed the δ13C and δ15N values of 15 prey species constituting 84% of the species found in stomach contents. We used these data to establish a trophic enrichment factor (TEF) to inform dietary analysis using a Bayesian isotope mixing model. We document a TEF of 0‰ and 2.0‰ for δ13C and δ15N, respectively. The dietary results showed that all demographic groups relied heavily on low trophic level seagrass‐associated prey. Bayesian standard ellipse areas (SEAb) were calculated to assess diversity in resource use. The SEAb of females was nearly four times larger than that of males indicating varied resource use, likely a consequence of small home ranges and habitat specialization. Juveniles possessed an intermediate SEAb, generally feeding at a lower trophic level compared to females, potentially an effect of natal philopatry and immature foraging skills. The small SEAb of males reflects a high degree of specialization on seagrass associated prey. Patterns in resource use by the demographic groups are likely linked to differences in the relative importance of social and ecological factors. 相似文献
73.
Raina K. Plowright Peggy Eby Peter J. Hudson Ina L. Smith David Westcott Wayne L. Bryden Deborah Middleton Peter A. Reid Rosemary A. McFarlane Gerardo Martin Gary M. Tabor Lee F. Skerratt Dale L. Anderson Gary Crameri David Quammen David Jordan Paul Freeman Lin-Fa Wang Jonathan H. Epstein Glenn A. Marsh Nina Y. Kung Hamish McCallum 《Proceedings. Biological sciences / The Royal Society》2015,282(1798)
Viruses that originate in bats may be the most notorious emerging zoonoses that spill over from wildlife into domestic animals and humans. Understanding how these infections filter through ecological systems to cause disease in humans is of profound importance to public health. Transmission of viruses from bats to humans requires a hierarchy of enabling conditions that connect the distribution of reservoir hosts, viral infection within these hosts, and exposure and susceptibility of recipient hosts. For many emerging bat viruses, spillover also requires viral shedding from bats, and survival of the virus in the environment. Focusing on Hendra virus, but also addressing Nipah virus, Ebola virus, Marburg virus and coronaviruses, we delineate this cross-species spillover dynamic from the within-host processes that drive virus excretion to land-use changes that increase interaction among species. We describe how land-use changes may affect co-occurrence and contact between bats and recipient hosts. Two hypotheses may explain temporal and spatial pulses of virus shedding in bat populations: episodic shedding from persistently infected bats or transient epidemics that occur as virus is transmitted among bat populations. Management of livestock also may affect the probability of exposure and disease. Interventions to decrease the probability of virus spillover can be implemented at multiple levels from targeting the reservoir host to managing recipient host exposure and susceptibility. 相似文献
74.
Zheng C Cao G Xia M Feng H Glenn J Anand R Zhang K Huang T Wang A Kong L Li M Galya L Hughes RO Devraj R Morton PA Rogier DJ Covington M Baribaud F Shin N Scherle P Diamond S Yeleswaram S Vaddi K Newton R Hollis G Friedman S Metcalf B Xue CB 《Bioorganic & medicinal chemistry letters》2011,21(5):1442-1446
We report the discovery of a potent, selective, and orally bioavailable dual CCR2 and CCR5 antagonist (3S,4S)-N-[(1R,3S)-3-isopropyl-3-({4-[4-(trifluoromethyl)pyridin-2-yl]piperazin-1-yl}carbonyl)cyclopentyl]-3-methoxytetrahydro-2H-pyran-4-amine (19). After evaluation in 28-day toxicology studies, compound 19 (INCB10820/PF-4178903) was selected as a clinical candidate. 相似文献
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Peggy S. M. Hill 《Ethology : formerly Zeitschrift fur Tierpsychologie》1999,105(6):531-545
Gryllotalpa major is a rare, burrowing insect native to the tallgrass prairie of the south-central United States and is known to exhibit 'lek-like' behavior during mating. Here I report on a study carried out in the field that demonstrates that the prairie mole cricket meets all criteria defining a classical lekking species. Males construct specialized acoustic burrows from which they call to attract females for mating. I show that these burrows, which seem to serve no purpose other than for sexual advertisement and mating, are aggregated spatially on at least three scalar levels. Females fly through the aggregation of burrows and drop to the ground in the vicinity of calling males, and are, thus, not constrained in choosing a mate. Females enter the males' acoustic burrows, but I argue that the burrows are not used as oviposition sites, and that the males do not otherwise sequester resources important to females. Although the term 'lek' is useful for the discussion of mating systems, its definition remains ambiguous. I discuss the current usage of the term and suggest extensions. 相似文献
80.
Peggy E. Pollak 《American journal of botany》1992,79(8):937-945
Ultrastructural differences were detected between a cytoplasmic male sterile tobacco cybrid (Nicotiana sp.) formed by protoplast fusion and normal, fertile tobacco. Cell structure was compared between anther primordia from normal, fertile tobacco and anther primordia from the cybrid using stereological methods. Particular emphasis was placed on the ultrastructure of mitochondria because of their known relationship to cytoplasmic male sterility in this cybrid and other plants. The volume density of mitochondria in cybrid anther primordia (6.3%) was significantly lower than in normal, fertile anther primordia (10.1%), although mitochondria from both plants contained similar amounts of cristae and profiles were of similar relative area. Dictyosomes and vacuoles also differed in volume density but not at a statistically significant level. Although the volume density of plastids did not differ, a larger amount of starch was stored within plastids in cybrid anther primordia than in normal, fertile anther primordia. These results are compatible with the hypothesis that an abnormally low rate of mitchondrial replication, and the resultant limit on adenosine triphosphate production, could contribute to cytoplasmic male sterility in the cybrid. 相似文献