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471.
Sergio Osorio‐Canadas Xavier Arnan Anselm Rodrigo Anna Torné‐Noguera Roberto Molowny Jordi Bosch 《Ecology letters》2016,19(12):1395-1402
Bergmann's rule originally described a positive relationship between body size and latitude in warm‐blooded animals. Larger animals, with a smaller surface/volume ratio, are better enabled to conserve heat in cooler climates (thermoregulatory hypothesis). Studies on endothermic vertebrates have provided support for Bergmann's rule, whereas studies on ectotherms have yielded conflicting results. If the thermoregulatory hypothesis is correct, negative relationships between body size and temperature should occur in temporal in addition to geographical gradients. To explore this possibility, we analysed seasonal activity patterns in a bee fauna comprising 245 species. In agreement with our hypothesis of a different relationship for large (endothermic) and small (ectothermic) species, we found that species larger than 27.81 mg (dry weight) followed Bergmann's rule, whereas species below this threshold did not. Our results represent a temporal extension of Bergmann's rule and indicate that body size and thermal physiology play an important role in structuring community phenology. 相似文献
472.
Nicholas W. Florek Jason T. Weinfurter Sinthujan Jegaskanda Joseph N. Brewoo Tim D. Powell Ginger R. Young Subash C. Das Masato Hatta Karl W. Broman Olav Hungnes Susanne G. Dudman Yoshihiro Kawaoka Stephen J. Kent Dan T. Stinchcomb Jorge E. Osorio Thomas C. Friedrich 《Journal of virology》2014,88(22):13418-13428
473.
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475.
Carolina Camargo Jorge H. Maldonado Elvira Alvarado Rocío Moreno-Sánchez Sandra Mendoza Nelson Manrique Andrés Mogollón Juan D. Osorio Alejandro Grajales Juan Armando Sánchez 《Biodiversity and Conservation》2009,18(4):935-956
Climate change is posing new challenges to conservation because management policies on protected coral reefs are less effective
than they were before the current ecosystem degradation. Coral reefs, the most diverse and complex marine ecosystem provide
economic services for millions, but are seriously threatened worldwide because reef-building corals are experiencing bleaching
phenomena and a steady decline in abundance. The resources of a Marine Protected Area (MPA) in Cartagena, Colombia, are in
constant decline, despite a current management plan and on-site staff, urging new conservation actions. A multidisciplinary
team gathered to evaluate management effectiveness including biophysical, socioeconomic and governance indicators. Coral cover
and fish diversity and abundance were low both inside and outside the MPA, which suggests a limited efficiency of management.
Currently, the MPA is a reef with low coral cover and high algae cover as well as large dead coral areas, which are generally
signs of highly degraded reef habitats. Live coral cover in the MPA was represented by pioneer coral species such as Agaricia tenuifolia and Porites astreoides. Nonetheless, 35% of the scleractinian species sampled in the area harbored more than one zooxanthellae symbiont, which suggests
potential resistance and resilience against coral bleaching. Maintenance of trophic structure and functional diversity is
an important endeavor that should be a priority for management in order to allow ecosystem resilience. Social and governance
indicators showed low-income levels and few opportunities for communities living in and around the park, low governability,
weak communication among stakeholders and with authorities at different levels. As a result, problems related to over exploitation
of resources were commonplace in the MPA. These results reflect low adaptive capacity of communities to comply with restrictive
conservation rules, showing that establishment of a protected area is a necessary but insufficient condition to guarantee
conservation goals. Ignoring the role of local communities only will exacerbate the problems associated with natural resources.
Involvement of communities in strategic ecosystems management appears to be a requisite to improve effectiveness of protected
areas, and participatory strategies, such as co-management, offer opportunities to improve governability while letting communities
adapt to MPA needs. 相似文献
476.
The Cry1Ab δ-endotoxin V171C mutant protein exhibits a 25-fold increase in toxicity against Lymantria dispar, which correlates with a faster rate of partitioning into the midgut membrane and slightly decreased protein stability. This is an insect-specific mechanism; similar results were not observed in Manduca sexta, another Cry1Ab δ-endotoxin-susceptible insect. 相似文献
477.
C R Osorio M D Collins A E Toranzo J L Barja J L Romalde 《Applied and environmental microbiology》1999,65(7):2942-2946
The causative agent of fish pasteurellosis, the organism formerly known as Pasteurella piscicida, has been reclassified as Photobacterium damselae subsp. piscicida on the basis of 16S rRNA gene sequence comparisons and chromosomal DNA-DNA hybridization data; thus, this organism belongs to the same species as Photobacterium damselae subsp. damselae (formerly Vibrio damselae). Since reassignment of P. damselae subsp. piscicida was based on only two strains, one objective of the present work was to confirm the taxonomic position of this fish pathogen by sequencing the 16S rRNA genes of 26 strains having different geographic and host origins. In addition, a nested PCR protocol for detection of P. damselae based on 16S rRNA was developed. This PCR protocol was validated by testing 35 target and 24 nontarget pure cultures, and the detection limits obtained ranged from 1 pg to 10 fg of DNA (200 to 20 cells). A similar level of sensitivity was observed when the PCR protocol was applied to fish tissues spiked with bacteria. The PCR approach described in this paper allows detection of the pathogen in mixed plate cultures obtained from asymptomatic fish suspected to be carriers of P. damselae subsp. piscicida, in which growth of this bacterium cannot be visualized. Our results indicate that the selective primers which we designed represent a powerful tool for sensitive and specific detection of fish pasteurellosis. 相似文献
478.
Lyda Osorio Marcela Uribe Gloria Ines Ardila Yaneth Orejuela Margarita Velasco Anilza Bonelo Beatriz Parra 《Memórias do Instituto Oswaldo Cruz》2015,110(4):510-516
There is insufficient evidence of the usefulness of dengue diagnostic tests under
routine conditions. We sought to analyse how physicians are using dengue diagnostics
to inform research and development. Subjects attending 14 health institutions in an
endemic area of Colombia with either a clinical diagnosis of dengue or for whom a
dengue test was ordered were included in the study. Patterns of test-use are
described herein. Factors associated with the ordering of dengue diagnostic tests
were identified using contingency tables, nonparametric tests and logistic
regression. A total of 778 subjects were diagnosed with dengue by the treating
physician, of whom 386 (49.5%) were tested for dengue. Another 491 dengue tests were
ordered in subjects whose primary diagnosis was not dengue. Severe dengue
classification [odds ratio (OR) 2.2; 95% confidence interval (CI) 1.1-4.5], emergency
consultation (OR 1.9; 95% CI 1.4-2.5) and month of the year (OR 3.1; 95% CI 1.7-5.5)
were independently associated with ordering of dengue tests. Dengue tests were used
both to rule in and rule out diagnosis. The latter use is not justified by the
sensitivity of current rapid dengue diagnostic tests. Ordering of dengue tests appear
to depend on a combination of factors, including physician and institutional
preferences, as well as other patient and epidemiological factors. 相似文献
479.
We propose a strategy for early vision which tailors visual channels to the object-oriented characteristics of natural scenes. This strategy involves essentially two types of channel, one for encoding the locally dominant edges which form the boundaries of 'objects', and another for 'filling in' the regions within them. The selection of contrasts which characterize object boundaries rather than textural detail can be enhanced by making an estimate local of contrast, and setting a threshold accordingly. This procedure and other aspects of the model were first suggested by observations of insect visual cells. 相似文献
480.
The rabbit heteroantisera anti-Meth A sarcoma (H-2d) (RAMA) and rabbit anti-RBL-5 leukemia (H-2b) (RAR-5) have been used to study the presence of normal strain antigens on the surface of different murine tumour cells. RAR-5 detected H-2-like structures on TLX9 (H-bb) lymphoma, however RAMA did not on LSTRA leukemia (H-2d) mastocytoma. Neither RAR-5 nor RAMA contained antibodies against non-H-2 and differentiation antigens. 相似文献