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991.
Pulsed-field gel electrophoresis of the genomic restriction fragments of coagulase-negative staphylococci 总被引:2,自引:0,他引:2
árka Snopková Friedrich Götz Jií Doka Stanislav Rosypal 《FEMS microbiology letters》1994,124(2):131-139
Abstract The genomes of 47 coagulase-negative staphylococcal strains assigned to different species were analysed by pulsed-field electrophoresis. The strains were clustered on the basis of their similarity in the Sma I restriction patterns into various groups, each group consisting of the type strain and the strains whose Sma I restriction patterns were similar to that of the type strain. The Sma I restriction groups seem to correspond to the following species: Staphylococcus warneri, S. hominis, S. xylosus, S. lugdunensi, S. kloosii, S. haemolyticus, S. lentus, S. cohnii, S. equorum, S. chromogenes, S. saprophyticus, S. simulans, S. carnosus, S. capitis and S. auricularis . The species S. sciuri, S. caseolyticus, S. gallinarum, S. epidermidis and S. schleiferi were represented only by their type strains and showed no similarity in their Sma I restriction patterns neither to each other nor to all the species investigated here. Thus, the classification of coagulase-negative staphylococcal strains into the above species seems to be confirmed also by genome restriction analysis carried out by pulsed-field gel electrophoresis. 相似文献
992.
Three sex pheromonal components, (Z)-11-hexadecenal (Z11–16:Ald), (Z)-11-hexadecenol (Z11–16:OH), and hexadecanal (16:Ald),
in a ratio of 88.0∶7.2∶4.8, were identified from ovipositor extracts of the fulvous clover moth,Heliothis maritima Grasl. (Lepidoptera: Noctuidae) by gas chromatographymass spectrometry. In addition, trace amounts of (Z)-9-hexadecenal (Z9–16:Ald)
were detected in the extracts by GC. A blend of Z11–16:Ald, Z11–16:OH and 16:Ald in a ratio of 100∶6∶3, as well as in combination
with 0.1 or 1 part Z9–16:Ald was tested at 0.01, 0.1, 1.0 and 10.0 μg doses in a flight tunnel. In flight tunnel tests male
behavioral responses elicited by 0.1 or 1.0 μg doses of the 100∶6∶3∶1 blend were similar to those elicited by an ovipositor
extract at 2 female equivalents. Deletion of Z9–16:Ald from the blend at 0.1 μg dose caused a decrease in the male response.
In the field test, however, presence or absence of Z9–16:Ald did not significantly influence the number of males trapped in
sticky traps with rubber septa containing 100 μg of the respective blends. 相似文献
993.
Ling Zhang Qingqing Lu Zengwei Yuan Songyan Jiang Huijun Wu 《Journal of Industrial Ecology》2023,27(2):587-600
This study predicted the metabolic process of the residential building system in China toward 2050 by addressing the detailed provincial patterns and urban–rural disparity and the characterizing metabolisms of building materials in detail. The results show that after a rapid growth during 1980–1990, the in-use stocks of residential buildings in China are expected to slow down in around 2030, reaching 75 billion m2 in 2050. Urban regions will account for 80% of total stocks, and provinces in the eastern and southern coastal areas will have the largest share. As demolition lags construction, the end-of-life residential buildings will continue to grow steadily with huge urban–rural and provincial differences, reaching 1.4 billion m2 by 2050. Regarding the metabolism of building materials, the inflow of most materials will decrease after 2030, while the outflow will increase steadily toward inflow. Based on the recycling outlook of construction and demolition waste and the corresponding environmental benefit, it is indicated that under the Chinese government's ambitious planning and vigorous promotion, prior to the middle of the century, the building system has the potential to transition to a sustainable future that meets residents’ housing needs with a remarkable decreasing input of raw materials thereby notably decreasing pressures on the environment, which will significantly benefit the goal of carbon neutrality in China. 相似文献
994.
Changes in the density of microtubular mesh-works were analysed in mesophyll cells and mesophyll derived protoplasts of Nicotiana tabacum L. and Triticum aestivum L. during leaf development. The main purpose of this study was to test whether the low density, if not lack, of microtubular networks recently described in protoplasts that had been isolated from fully differentiated mesophyll cells happened during protoplast isolation or whether the loss of microtubules actually occurred during differentiation of the leaf tissue. Immunofluorescence microscopy showed that the density of the microtubular cytoskeleton in the leaf tissue decreased steadily after cessation of cell growth in both species. Nevertheless, in Triticum microtubule disappearance was swifter and occurred along a gradient from the base to tip of the leaf, a phenomenon reflecting the differences in the ontogeny between the dicotyledonous Nicotiana and the mono-cotyledonous Triticum leaves. Protein extraction from leaf tissues and Western blot analysis indicated that in both species the disappearance of microtubules was the result of a degradation of tubulin and not only due to a depolymerisation into tubulin subunits. When the cell walls were removed from live cells and the protoplasts released, the original patterns of the microtubules became obscured and, particularly in differentiated cells, the integrity and density of the microtubule strands deteriorated. The potential application of the density of the microtubular cytoskeleton as a marker in studies on differentiation and dedifferentiation in mesophyll cells and protoplasts is discussed.We wish to thank Silke Heichel for excellent technical assistance. We also express our thanks to the group of A.M. Lambert at CNRS, Strasbourg, France, for advice during establishment of our Western blot system. The work was supported by a grant of the German Ministry of Science and Technology (BMFT). 相似文献
995.
Liam N. Nash Lucas W. Zorzetti Pablo A. P. Antiqueira Chris Carbone Gustavo Q. Romero Pavel Kratina 《Global Ecology and Biogeography》2023,32(8):1323-1335
Aim
Emerging aquatic insects link aquatic and terrestrial ecosystems across the Earth. Their diversity, abundance and functional importance means their emergence is an important phenological event. Nevertheless, aquatic insect emergence is understudied at a global scale compared to other phenological events, despite changing phenology being one of the most significant ecological responses to climate change. Here, we quantitatively describe the global patterns, and key proposed drivers, of seasonal aquatic insect emergence, to further understand how these patterns might change in the future.Location
Global.Time Period
1950–2018.Major Taxa Studied
Emerging aquatic insects.Methods
We extracted monthly emergence data from 86 studies across 163 sites to construct 1053 annual emergence curves. We parameterized the curves using two complementary metrics of seasonality, which were modelled against geographical and climatic variables to determine the direct and indirect relationships between them.Results
We found clear global trends in aquatic insect emergence patterns across latitude and underlying climates. Between-month variation and temporal restriction of emergence increased from the equator to the poles, going from small, aseasonal fluctuations in the warm, thermally stable tropics to large, seasonal peaks at cooler, thermally unstable higher latitudes. While emergence trends were associated with gradients of precipitation, temperature was the dominant climatic driver of the latitudinal trend.Main Conclusions
These findings suggest that with climate warming, aquatic insects will emerge over longer periods, diluted in abundances and displaying less seasonal emergence patterns with smaller between-month fluctuations. This may result in disruption of ecosystem functions seasonally dependent on aquatic insects, such as riparian predation, pollination and disease transmission. The cross-ecosystem life cycle of aquatic insects means changes to their seasonal patterns of emergence will have impacts in both aquatic and terrestrial ecosystems. 相似文献996.
High-quality data on species distribution and knowledge of species ecology are necessary pre-requisites for their effective conservation. In the European Union, a network of protected areas called the “Natura 2000 network” was set up to conserve the most valuable and threatened species. The Natura 2000 network was supposed to improve rare species conservation, but has it? In this paper, an analysis of data collected from 1 × 1 km grids on the distribution of orchids in East Macedonia (NE Greece) in two consecutive periods of time (before and after 2010), revealed the degree to which a larger data set (including both periods instead of only one) improved our knowledge of the distributions of species and whether the Natura 2000 network can be used as a basis for the conservation of the orchid flora in this area. When the data for the first period and cumulative data for both periods were compared, orchid species richness and density were very similar. However, comparison of the two datasets showed that more orchid taxa were recorded per grid in the first than the second period. However, based on the surveys in the second period, the knowledge on orchid distribution increased significantly. In particular, ten orchid taxa were recorded for the first time in East Macedonia during the second period and significantly more (54.79 % of the total number of species) were recorded. This resulted in a better understanding of their altitudinal requirements. It also confirmed that most of the orchid-rich grid cells in East Macedonia overlap with the Natura 2000 network, which highlights importance of Natura 2000 for orchid conservation. 相似文献
997.
Philip A. Clapp Michael J. Davies Madeline S. French Bruce C. Gilbert 《Free radical research》1994,21(3):147-167
E.P.R. spin trapping has been employed to study radical production during the bactericidal action of three peroxide compounds (peracetic acid, 4-percarboxy-N-isobutyltrimellitimide and magnesium monoperoxyphthalate) upon both Gram negative (Escherichia Coll) and Gram positive (Staphylococcus Aureus) bacteria. Use of the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) has allowed direct detection of both carbon-centred and hydroxyl radicals, which are produced at varying rates for the different bacteria/peracid systems studied. The inhibition of bactericidal action, by DMPO and two antioxidants, Vitamin C and Trolox C, indicates that radicals are the lethal species and evidence is presented which suggests that radical production is internal to the bacterial cell. Hydroxyl radicals are believed to be the lethal species. The effect of added iron chelators and haem protein inhibitors indicates that iron species and haem proteins in particular are involved. A marked variation is found in observed hydroxyl-radical adduct signals with both the nature and concentration of peracid. A strong inverse correlation is found between the concentration of the observed radical adduct signal and the relative strength of the peroxide as a bactericide; use of a stable nitroxide as a radical scavenger confirms that strong bactericides produce radicals at a much faster rate than weak bactericides. Plots of radical generation versus time are correlated with % bacterial kill, offering further evidence that hydroxyl radicals are the lethal species. 相似文献
998.
999.
In a sub-Arctic band of Hare Indians, considerable discrepancies have been found in the style, consistency, and degree of environmental involvement characterizing different individuals and families. The distinct subsistence patterns of subgroups within the population are explored. Ideological, psychological, historical, and experiential factors that contribute to this variability are examined. These factors are seen to affect strategies concerning trapping, hunting, mobility, wage labor, identity maintenance, and the quality of life that people seek. While some individuals pursue freedom from traditional subsistence hardships, others focus on self-sufficiency and freedom from constraints imposed by greater integration with Western society. 相似文献
1000.
Johann Greilhuber 《Plant Systematics and Evolution》1978,130(3-4):223-233
DNA contents have been determined cytophotometrically in the three Central European, relatedScilla speciesS. bifolia (2n = 18, 2 x, 1 C = 6.2 pg),S. drunensis (2n = 36, 4 x, 1 C = 12.8 pg), andS. vindobonensis (2n = 18, 2 x, 1 C = 9.4 pg). The tetraploid speciesS. drunensis contains twice as much DNA as the diploidS. bifolia. However, the diploid speciesS. vindobonensis differs in DNA content fromS. bifolia by a factor of about 1.5. This difference is largely due to euchromatic DNA, although the higher DNA content inS. vindobonensis is combined with higher heterochromatin content. The data indicate thatS. bifolia andS. drunensis on the one hand, andS. vindobonensis on the other hand are phyletically well separated. Previous taxonomic conclusions from morphology as well as C-banding are thus corroborated.Evolution ofScilla and Related Genera, V. 相似文献