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941.
一种从土壤样品中选择性分离假诺卡氏菌的方法 总被引:3,自引:0,他引:3
为提高假诺卡氏放线菌的分离效率,根据其营养特性和对抗生素的敏感性,设计、检验了5种选择性分离培养基;实验检测了模式菌株在不同培养基上的生长情况,结果表明培养基S1和S2对假诺卡氏菌的生长有显著的选择性。经该方法从韩国、印度尼西亚和中国广西地区不同土样中分离到一些假诺卡氏放线菌。 相似文献
942.
Sonia Cristina Zapata Alejandro Travaini Pablo Ferreras Miguel Delibes 《European Journal of Wildlife Research》2007,53(4):276-286
We evaluated the existence of trophic guild structure, considering seasonal and annual variation, in two terrestrial carnivore assemblages: one from Santa Cruz province (Argentinean Patagonia, composed by six carnivore species), and the other from Doñana National Park (SW Spain, composed by five carnivore species). To identify trophic guilds, we first studied seasonal and annual diets of predators, calculated trophic overlap among species pairs, and then constructed overlap matrices (similarity matrices). We determined guild membership objectively by entering the similarity matrices into the clustering technique unweighted pair-group method with arithmetic averaging. Carnivores from both assemblages were grouped, respectively, into four feeding guilds. Lagomorphs and rodents promoted the formation of two feeding guilds in both study sites, although the taxonomic composition of predator species that composed them was different. The ungulates-edentates feeding guild was only present at Santa Cruz, whereas the birds and reptiles feeding guild was only present at Doñana. Invertebrates and fruits were the base for the formation of a guild composed by species of the same taxonomic origin both in Santa Cruz and Doñana. Guild structure of Santa Cruz and Doñana assemblages did not exhibit seasonal or annual variation, although the specific guild composition changed over the two studied periods for both assemblages. This structure probably responded to discontinuities in resource spectra in Santa Cruz and fluctuations in rabbit abundance in Doñana. Our results support the hypothesis that establishes that guilds are originated by opportunistic convergence of species on abundant and energetically rewarding resources. 相似文献
943.
Vogt S Portig I Irqsusi M Ruppert V Weber P Ramzan R 《Journal of bioenergetics and biomembranes》2011,43(4):425-435
Induction of heat shock proteins (hsp) has been shown to protect cells from ischemia by providing transient tolerance against
myocardial injury and improving postischemic functional recovery. Attenuation of ATP depletion and earlier restoration of
ATP content on reperfusion are thought to play a role in this scenario. Hsp induction is accompanied by altered enzyme activity
of the respiratory chain, the major generator of ATP under physiological conditions. This report addresses the question whether
processing and final assembly of the active holoenzyme cytochrome c oxidase (CcO, complex IV), member of the respiratory chain,
is compromised under hypoxic conditions unless protected by stress proteins. Special focus is laid on function of the enzyme’s
subunits and importance of cellular energy availability and maintenance. 相似文献
944.
945.
Roy Mackenzie Javier A. Barros Miguel A. Martínez 《World journal of microbiology & biotechnology》2011,27(11):2499-2504
Aerobic heterotrophic bacteria present in the surface water of three cold and nutrient-poor lakes in the Chilean Patagonia
(Alto Reino, Las Dos Torres and Venus) were analysed for genetic similarity and metabolic diversity using 16S ribosomal DNA
and the Biolog EcoPlateTM system, respectively. Bacterial fingerprints of water samples in enriched and non-enriched nutrient broth demonstrated a
>50% fingerprinting similarity between the lakes. Metabolic activity was also similar. However, the Biolog EcoPlateTM system carbon substrates revealed functional diversity. Lake Las Dos Torres showed the most fingerprinting similarity between
enriched and non-enriched cold water samples. The amounts of living and viable bacteria were also higher in this lake’s water
sample, suggesting a predominance of facultative oligotrophic groups. DNA sequencing analysis demonstrated the presence of
phylum Bacteroidetes in Lake Alto Reino; phyla Bacteroidetes and Gammaproteobacteria in Lake Las Dos Torres; and phyla Bacteroidetes,
Alphaproteobacteria, and Gammaproteobacteria in Lake Venus. Although each lake had a unique bacterial community structure,
the different bacterial groups may be performing similar metabolic functions, given the similarity in extreme environmental
conditions. 相似文献
946.
947.
Pascal Fournier Christian Maizeret David Jimenez Jean-Pierre Chusseau Stéphane Aulagnier François Spitz 《Acta theriologica》2007,52(1):1-12
The European minkMustela lutreola Linnaeus, 1761 and the European polecatMustela putorius Linnaeus, 1758 are related species sympatric in southwestern France. The European mink is rapidly disappearing whereas the
polecat maintains good populations. Seasonal habitat use of both species was compared in the Landes de Gascogne region to
identify if some vulnerability factors of the European mink were associated with habitats occupied by this mustelid. Potential
habitats were mapped using a satellite picture and 12 main types of habitats were defined. Animal locations were recorded
by radiotracking 9 European mink and 14 polecats from March 1996 to August 1999. Resting animals were located by triangulation,
and, when possible, resting places were described. Animals in activity were tracked by continuous monitoring. Data collected
revealed a strong preference of European mink for flooded habitats, particularly open marshes, flooded woodlands and moorlands.
They seldom left the corridor of the riparian forest and their resting places were mainly in flooded environments, above ground
(under herbs or bushes) or in cavities between tree roots. European polecats were less tightly linked to wetlands. Most of
their locations were in the pine forests outside the valleys and their resting places were mainly in burrows. The strong specialisation
of European mink in aquatic habitats is probably one of the main reasons for its decline because wetlands suffer drastic damages
throughout all of its range. Maintaining adequate water levels is crucial for satisfying habitat requirements of mink. 相似文献
948.
Jiangfeng Zhu Xiaojie Dai Liuxiong Xu Xinjun Chen Yong Chen 《Environmental Biology of Fishes》2011,91(1):95-102
Polyandry is extremely common across a wide range of organisms. In promiscuous mating systems, females are often sexually
harassed by males, but at the same time obtain benefits from multiple mating. It remains unclear whether polyandry is exclusively
imposed by males or is also promoted by females. Here, we investigated this question by recording the time spent by female
guppies near a single male or a group of males with similar size and colour patterns over three consecutive days. We accounted
for the effect of shoaling by using a control treatment where a group of females was used instead of a group of males. Results
showed that females spent significantly more time near the group of males, but not with the group of females. In the presence
of a group of males, total female mating preference time did not change over the course of the study, but rather shifted from
spending more time near the single male at the beginning of the experiment to spending more time near the group of males.
The consequence of this female preference for associating with a group of males in a non-experimental setup would be to promote
multiple mating. Our result indicates that polyandry in guppies is at least partially encouraged by females, and not entirely
a consequence of male sexual behaviour. 相似文献
949.
Manoj Kumar Vladimir León Angela De Sisto Materano Olaf A. Ilzins 《World journal of microbiology & biotechnology》2007,23(2):211-220
A Bacillus sp. strain DHT, isolated from oil-contaminated soil, grew and produced biosurfactant when cultured in variety of substrate
at salinities of up to 100 g l−1 and temperatures up to 45°C. It was capable of utilizing crude oil, fuels, various pure alkanes and PAHs as a sole carbon
and energy source across a wide range of temperature and salinity. Over the range evaluated, the degradation of hydrocarbon
and biosurfactant production was not influenced by salinity (0–10% wv−1) and temperature (30–45°C). The biosurfactant produced by the organism emulsified a range of hydrocarbons with hexadecane
as the best substrate and toluene as the poorest. From 16S rDNA analysis, strain DHT was related to Bacillus licheniformis. 相似文献
950.