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991.
Júlia Margit Aszalós Gergely Krett Dóra Anda Károly Márialigeti Balázs Nagy Andrea K. Borsodi 《Extremophiles : life under extreme conditions》2016,20(5):603-620
Ojos del Salado, the highest volcano on Earth is surrounded by a special mountain desert with extreme aridity, great daily temperature range, intense solar radiation, and permafrost from 5000 meters above sea level. Several saline lakes and permafrost derived high-altitude lakes can be found in this area, often surrounded by fumaroles and hot springs. The aim of this study was to gain information about the bacterial communities inhabiting the sediment of high-altitude lakes of the Ojos del Salado region located between 3770 and 6500 m. Altogether 11 sediment samples from 4 different altitudes were examined with 16S rRNA gene based denaturing gradient gel electrophoresis and clone libraries. Members of 17 phyla or candidate divisions were detected with the dominance of Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes. The bacterial community composition was determined mainly by the altitude of the sampling sites; nevertheless, the extreme aridity and the active volcanism had a strong influence on it. Most of the sequences showed the highest relation to bacterial species or uncultured clones from similar extreme environments. 相似文献
992.
993.
Andrew?M.?RitchieEmail authorView authors OrcID profile Nathan?Lo Simon?Y.?W.?Ho 《Organisms Diversity & Evolution》2016,16(3):467-480
Defining and understanding species diversity forms the basis of a wide range of biological and conservation work. Traditional taxonomy can be complemented and accelerated using molecular methods of species delimitation, such as the widely used Generalised Mixed Yule-Coalescent (GMYC) approach. This method uses time-calibrated phylogenetic trees in order to identify transition points between inter- and intraspecific divergence processes. Despite some important limitations, the GMYC approach appears to be robust to a wide range of dataset characteristics. It is one of the few model-based species-delimitation methods that remain practical for analysing molecular datasets with a large numbers of taxa. Most GMYC analyses have been based on datasets consisting of one or a small number of mitochondrial genes. To investigate the sensitivity of GMYC to the choice of mitochondrial marker, we compared GMYC estimates from 15 mitochondrial genes for three vertebrate datasets (cetaceans, ursids and whitefish). Despite the shared evolutionary history among mitochondrial genes, different markers exhibited substantial variation in GMYC delimitation results across all three datasets. This variability was not restricted to specific genes or taxa and extended to commonly used barcoding genes such as COI and CYTB. Using multiple concatenated markers mitigated these problems in two of the datasets, but exacerbated systematic biases present in a third. Our findings indicate the need to consider multiple markers, loci and lines of evidence when performing molecular species delimitation. 相似文献
994.
The effect of intraspecific variation and heritability on community pattern and robustness 下载免费PDF全文
Intraspecific trait variation is widespread in nature, yet its effects on community dynamics are not well understood. Here we explore the consequences of intraspecific trait variation for coexistence in two‐ and multispecies competitive communities. For two species, the likelihood of coexistence is in general reduced by intraspecific variation, except when the species have almost equal trait means but different trait variances, such that one is a generalist and the other a specialist consumer. In multispecies communities, the only strong effect of non‐heritable intraspecific variation is to reduce expected species richness. However, when intraspecific variation is heritable, allowing for the possibility of trait evolution, communities are much more resilient against environmental disturbance and exhibit far more predictable trait patterns. Our results are robust to varying model parameters and relaxing model assumptions. 相似文献
995.
Niche partitioning due to adaptive foraging reverses effects of nestedness and connectance on pollination network stability 下载免费PDF全文
Fernanda S. Valdovinos Berry J. Brosi Heather M. Briggs Pablo Moisset de Espanés Rodrigo Ramos‐Jiliberto Neo D. Martinez 《Ecology letters》2016,19(10):1277-1286
Much research debates whether properties of ecological networks such as nestedness and connectance stabilise biological communities while ignoring key behavioural aspects of organisms within these networks. Here, we computationally assess how adaptive foraging (AF) behaviour interacts with network architecture to determine the stability of plant–pollinator networks. We find that AF reverses negative effects of nestedness and positive effects of connectance on the stability of the networks by partitioning the niches among species within guilds. This behaviour enables generalist pollinators to preferentially forage on the most specialised of their plant partners which increases the pollination services to specialist plants and cedes the resources of generalist plants to specialist pollinators. We corroborate these behavioural preferences with intensive field observations of bee foraging. Our results show that incorporating key organismal behaviours with well‐known biological mechanisms such as consumer‐resource interactions into the analysis of ecological networks may greatly improve our understanding of complex ecosystems. 相似文献
996.
Relationships between wild bees,hoverflies and pollination success in apple orchards with different landscape contexts 下载免费PDF全文
Ádám Kőrösi László Somay Zoltán Elek Viktor Markó Miklós Sárospataki Réka Bakos Ákos Varga Katinka Nyisztor András Báldi 《Agricultural and Forest Entomology》2016,18(1):68-75
997.
Break the pattern: breakpoints in beta diversity of vertebrates are general across clades and suggest common historical causes 下载免费PDF全文
Adrián Castro‐Insua Carola Gómez‐Rodríguez Andrés Baselga 《Global Ecology and Biogeography》2016,25(11):1279-1283
The use of correlative analyses might be insufficient to understand the processes that control biodiversity, because the variables accounting for different hypotheses (e.g. current climate, past climate change, post‐glacial dispersal limitation) are mutually correlated. We suggest here that, in order to gain insight, it could be useful to search for latitudinal thresholds that could provide information about qualitative changes in the way biodiversity varies in space. Such tipping points could inform about higher‐level processes that are not reflected in correlative analyses. We test whether similar breakpoints in latitudinal beta‐diversity patterns exist for different vertebrate groups with diverse life histories and dispersal abilities. In birds, bats and non‐volant mammals we find breakpoints similar to those of amphibians. Differences in species composition are mainly due to species replacement from the equator to the breakpoint, but are dominated by nested species losses from the breakpoint to higher latitudes. Thus, marked thresholds discriminate two world regions where different processes appear to drive biodiversity. 相似文献
998.
Precocious flowering of juvenile citrus induced by a viral vector based on Citrus leaf blotch virus: a new tool for genetics and breeding 总被引:1,自引:0,他引:1 下载免费PDF全文
Karelia Velázquez Jesús Agüero María C. Vives Pablo Aleza José A. Pina Pedro Moreno Luis Navarro José Guerri 《Plant biotechnology journal》2016,14(10):1976-1985
The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus‐based vector (clbvINpr‐AtFT and clbvINpr‐CiFT, respectively). Citrus plants of different genotypes graft inoculated with either of these vectors started flowering within 4–6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology in comparison with noninoculated adult plants. The vector did not integrate in or recombine with the plant genome nor was it pollen or vector transmissible, albeit seed transmission at low rate was detected. The clbvINpr‐AtFT is very stable, and flowering was observed over a period of at least 5 years. Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up genetic studies and breeding programmes. 相似文献
999.
Xanthomonas campestris attenuates virulence by sensing light through a bacteriophytochrome photoreceptor 下载免费PDF全文
1000.
Kwame?YeboahEmail authorView authors OrcID profile Daniel?A.?Antwi Ben?Gyan Virginia?Govoni Charlotte?E.?Mills J.?Kennedy?Cruickshank Albert?G.?B.?Amoah 《BMC endocrine disorders》2016,16(1):53