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Beyond biodiversity: individualistic controls of invasion in a self-assembled community 总被引:5,自引:0,他引:5
Recent experimental and simulation results, and competition‐based ecological theory, predict a simple relationship between species richness and the invasibility of communities at small spatial scales – likelihood of invasion decreases with increasing richness. Here we show data from 42 continuous years of sampling old field succession that reveal quite different dynamics of plant invasion. Contrary to experimental studies, when richness was important in explaining invasion probability, it was typically positively associated with species invasion. Invasion of several species had a unimodal response to resident species richness, which appeared to be a mixture of compositional influences and a richness effect. Interestingly, invasions by native and exotic species did not fundamentally differ. Control of species invasion in this system is individualistic, caused by a variety of community‐level mechanisms rather than a single prevailing richness effect. 相似文献
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Numerous species of birds break hard-shelled prey items by droppingthem
from a height. This intriguing prey-extraction method providesan excellent
opportunity for studying foraging behavior becausea single, easily measurable
quantityheight of dropmaybe influenced by a wide variety of
identifiable characteristicsof the prey (e.g., breakability, weight) and
social environment(e.g., alone or in the presence of kleptoparasites). Using
adynamic, state variable modeling approach, this paper presentsthe first
theoretical framework for avian prey-dropping systemsthat incorporates the
diversity of prey characteristics andsocial situations. The model yielded a
series of qualitativepredictions about prey-dropping behavior that can be
testedreadily in any prey-dropping system. In particular, the results
indicatedthat quantitative and qualitative differences in item breakability
andpotential kleptoparasitism should have a significant effecton the height
and pattern of prey dropping. 相似文献
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《Endocrine practice》2022,28(11):1159-1165
ContextThe Accreditation Council for Graduate Medical Education has instituted common program requirements related to diversity, equity, and inclusion (DEI) for postgraduate trainees in the United States; however, the extent to which DEI training is being incorporated across endocrinology fellowship programs is unknown.ObjectivesTo describe the sociodemographic representation and DEI training experiences within endocrinology fellowship programs.Design, setting, and participantsNational cross-sectional survey study of fellows and fellowship program leaders in the United States whose fellowships were members of the Association of Program Directors in Endocrinology and Metabolism.Main outcome measures(1) Demographics of fellows and program leaders and (2) programs’ experience, confidence, and interest in formal DEI training.ResultsA total of 108 and 106 fellow and faculty responded to the survey, respectively. The majority of fellows and faculty are female. Less than 3% of fellows and 3.7% of faculty identify as Black. More than 90% of fellows/faculty are heterosexual and no respondents identified as transgender/nonbinary; however, 5% and 2% of all respondents preferred not to disclose their sexual orientation and gender identity, respectively. While 85% of faculty received institutional diversity and inclusion training, 67.6% of fellows did. Fellows are more likely to have received training in health equity than program leaders. Both fellows and program leaders express a high interest in health equity curriculum.ConclusionsWithin the diversity of endocrinology training programs, Black physicians are underrepresented in medicine, which persists in endocrinology fellowships. Fellowship programs express enthusiasm for national diversity and health equity curricula, with the majority of programs reporting institutional DEI training. 相似文献
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