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81.
Evangelia Stergiakouli Romy Gaillard Jeremy M. Tavaré Nina Balthasar Ruth J. Loos Hendrik R. Taal David M. Evans Fernando Rivadeneira Beate St Pourcain André G. Uitterlinden John P. Kemp Albert Hofman Susan M. Ring Tim J. Cole Vincent W.V. Jaddoe George Davey Smith Nicholas J. Timpson 《Obesity (Silver Spring, Md.)》2014,22(10):2252-2259
82.
Alcántara-Sánchez F Reynaga-Peña CG Salcedo-Hernández R Ruiz-Herrera J 《Antonie van Leeuwenhoek》2004,86(4):301-311
The effects of the Ca2+/H+ exchanger A23187 and the K+/H+ exchanger nigericin on the growth of Neurospora crassa were analyzed. Both ionophores had the same effects on the fungus. They both inhibited growth in liquid media, apical extension
being more affected than protein synthesis. A sudden challenge to either ionophore on solid media rapidly stopped hyphal extension.
Additionally, both ionophores induced profuse mycelium branching and upward hyphal growth. Hyphae growing on nigericin-containing
media also burst at the apex. Both ionophores caused a rapid inhibition in the apically-occurring synthesis of structural
wall polysaccharides, but they did not affect mitochondrial energy conservation. With the use of DiBAC, a membrane-potential
sensitive fluorophore, it was excluded that their effects were due to depletion of the plasma membrane potential. Considering
that both ionophores exchange H+ for different metallic ions, we concluded that their effect was due to dissipation of a proton gradient, which is directly
or indirectly involved in the apical growth of the fungus.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
83.
Bimanual actions impose intermanual coordination demands not present during unimanual actions. We investigated the functional neuroanatomical correlates of these coordination demands in motor imagery (MI) of everyday actions using functional magnetic resonance imaging (fMRI). For this, 17 participants imagined unimanual actions with the left and right hand as well as bimanual actions while undergoing fMRI. A univariate fMRI analysis showed no reliable cortical activations specific to bimanual MI, indicating that intermanual coordination demands in MI are not associated with increased neural processing. A functional connectivity analysis based on psychophysiological interactions (PPI), however, revealed marked increases in connectivity between parietal and premotor areas within and between hemispheres. We conclude that in MI of everyday actions intermanual coordination demands are primarily met by changes in connectivity between areas and only moderately, if at all, by changes in the amount of neural activity. These results are the first characterization of the neuroanatomical correlates of bimanual coordination demands in MI. Our findings support the assumed equivalence of overt and imagined actions and highlight the differences between uni- and bimanual actions. The findings extent our understanding of the motor system and may aid the development of clinical neurorehabilitation approaches based on mental practice. 相似文献
84.
Treatment of tobacco ( Nicotiana tabacum L.) plants with lithium induces the formation of necrotic lesions and leaf curling as in the case of incompatible pathogen interactions. Further similarities at the molecular level include accumulation of ethylene and of salicylic and gentisic acids, and induced expression of pathogenesis-related PR-P, PR5 and PR1 genes. With the exception of PR1 induction, lithium produced the same effects in transgenic tobacco plants that do not accumulate salicylate because of overexpression of the bacterial hydroxylase gene nahG. On the other hand, inhibition of ethylene biosynthesis with aminoethoxyvinylglycine prevented lithium-induced cell death and PR5 expression. These results suggest that lithium triggers a hypersensitive-like response where ethylene signalling is essential. 相似文献
85.
86.
Introduced exotic species cause environmental changes and threat public health in target sites. Illegal trade has enhanced this problem. To first report these risks in Brazil, exotic snakes found in São Paulo City (SPC) (23°32 S, 46°38 W), southeastern Brazil, and sent to Instituto Butantan between 1995 and 2000, were listed and characterized by their biological attributes. Seventy-six individuals of sixteen alien species were collected. Euriecians snakes, mainly booids, were predominant. Using multivariate techniques, their ecological niches were compared to those of 26 native species, as a way to point out the resource's availability. To evaluate the potential of successful implantation, two species absent in SPC and considered as problem snakes are included in these analyses: the brown treesnake Boiga irregularis and the habu Trimeresurus flavoviridis. There were niche similarities between these pest snakes, exotic booids and native viperids largely due to the similarities in the chosen prey (mammals), diel activity (nocturnal), color pattern (variegated) and body size (medium to large). To avoid predictable undesirable effects of implanted pest snakes, traffic control and punishment should be improved, as well as parallel environmental education programs. 相似文献
87.
88.
Carmen Rojo Francesc Mesquita-Joanes Juan S. Monrós Javier Armengol Mahmood Sasa Fabián Bonilla Ricardo Rueda José Benavent-Corai Rubén Piculo M. Matilde Segura 《PloS one》2016,11(2)
The alternating climate between wet and dry periods has important effects on the hydrology and therefore on niche-based processes of water bodies in tropical areas. Additionally, assemblages of microorganism can show spatial patterns, in the form of a distance decay relationship due to their size or life form. We aimed to test spatial and environmental effects, modulated by a seasonal flooding climatic pattern, on the distribution of microalgae in 30 wetlands of a tropical dry forest region: the Pacific coast of Costa Rica and Nicaragua. Three surveys were conducted corresponding to the beginning, the highest peak, and the end of the hydrological year during the wet season, and species abundance and composition of planktonic and benthic microalgae was determined. Variation partitioning analysis (as explained by spatial distance or environmental factors) was applied to each seasonal dataset by means of partial redundancy analysis. Our results show that microalgal assemblages were structured by spatial and environmental factors depending on the hydrological period of the year. At the onset of hydroperiod and during flooding, neutral effects dominated community dynamics, but niche-based local effects resulted in more structured algal communities at the final periods of desiccating water bodies. Results suggest that climate-mediated effects on hydrology can influence the relative role of spatial and environmental factors on metacommunities of microalgae. Such variability needs to be accounted in order to describe accurately community dynamics in tropical coastal wetlands. 相似文献
89.
The effect of temperature, pH, water potential and sources of nitrogen and carbon on the biocontrol agent Penicillium oxalicum
were studied in vitro. The fungus is xerotolerant, mesophillic and has a wide pH tolerance. The parameters evaluated (germination,
germ tube length, growth rate and sporulation) showed different sensitivities to the environmental factors. Peptone and free
amino acids gave the highest growth rates and high levels of sporulation. Xylose, mannose and fructose gave the highest growth
rates and mannose induced strong sporulation. The effect of nutrients (mannose + arginine) and water potential was also studied
in vivo. The xerotolerant character of the fungus was confirmed. From this study we consider Penicillium oxalicum ecologically
competent to perform effectively as a biocontrol agent in the soil environment.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
90.
Marcio?Paulo?Pereira Felipe?Fogaroli?Corrêa Evaristo?Mauro?de?Castro Jean?Paulo?Vitor?de?Oliveira Fabricio?José?PereiraEmail author 《Protoplasma》2017,254(6):2117-2126
Previous works show the development of thicker leaves on tolerant plants growing under cadmium (Cd2+) contamination. The aim of this study was to evaluate the Cd2+ effects on the leaf meristems of the tolerant species Schinus molle. Plants were grown in nutrient solution containing 0, 10, and 50 μM of Cd2+. Anatomical analysis was performed on leaf primordia sampled at regular time intervals. Under the lowest Cd2+ level (10 μM), increased ground meristem thickness, diameter of the cells, cell elongation rate, and leaf dry mass were found. However, 50 μM of Cd2+ reduced all these variables. In addition, the ground meristem cells became larger when exposed to any Cd2+ level. The epidermis, palisade parenchyma, and vascular tissues developed earlier in Cd2+-exposed leaves. The modifications found on the ground meristem may be related to the development of thicker leaves on S. molle plants exposed to low Cd2+ levels. Furthermore, older leaves showed higher Cd2+ content when compared to the younger ones, preventing the Cd2+ toxicity to these leaves. Thus, low Cd2+ concentrations change the ground meristem structure and function reflecting on the development of thicker and enhanced leaves. 相似文献