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161.
BIANCA ETHEL GUTIÉRREZ-AMAVIZCA ANDREAS GAL ROCÍO ORTÍZ-OROZCO ULRICH ORTH ERNESTO PRADO MONTES DE OCA JAIME PAUL GUTIÉRREZ-AMAVIZCA LUIS E. FIGUERA 《Journal of genetics》2017,96(1):161-164
Fabry disease (FD) is a lysosomal storage disorder, which develops due to a deficiency in the hydrolytic enzyme, α-galactosidase A (α-Gal A). Alpha-Gal A hydrolyzes glycosphingolipid globotriaosylceramide (Gb3), and an α-Gal A deficiency leads to Gb3 accumulation in tissues and cells in the body. This pathology is likely to involve multiple systems, but it is generally considered to affect primarily vascular endothelium. In this study, we investigated mutations in the GLA gene, which encodes α-Gal A, in Mexican families with FD. We included seven probands with FD that carried known mutations. We analysed pedigrees of the probands, and performed molecular screening in 65 relatives with the potential of carrying a GLA mutation. Five mutations (P40S, IVS4 +4, G328V, R363H, R404del) were detected in seven unrelated Mexican families with the classic FD phenotype. Of the 65 relatives examined, 42 (64.6%) had a GLA gene mutation. In summary, among seven Mexican probands with FD, 65 relatives were at risk of carrying a known GLA mutation, and molecular screening identified 42 individuals with the mutation. Thus, our findings showed that it is important to perform molecular analysis in families with FD to detect mutations and to provide accurate diagnoses for individuals that could be affected. 相似文献
162.
We isolated 56 common buzzard (Buteo buteo) microsatellite loci from (AC)n‐ and (AAAG)n‐enriched genomic libraries. Eleven loci were tested on 90 individuals from Eastern Westphalia in Germany, yielding two to 17 alleles per locus (average 5.7) and expected heterozygosities ranging from 0.11 to 0.93 (average 0.53). These highly variable microsatellite markers provide a powerful means for investigating population genetic diversity in the common buzzard, a little‐understood aspect of this widespread species. 相似文献
163.
PAUL S. GILLER 《Journal of Applied Ecology》2005,42(2):201-207
164.
DAVID T. TINGEY ROBERT B. MCKANE DAVID M. OLSZYK MARK G. JOHNSON PAUL T. RYGIEWICZ E. HENRY LEE 《Global Change Biology》2003,9(7):1038-1050
The effects of elevated CO2 and temperature on principal carbon constituents (PCC) and C and N allocation between needle, woody (stem and branches) and root tissue of Pseudotsuga menziesii Mirb. Franco seedlings were determined. The seedlings were grown in sun‐lit controlled‐environment chambers that contained a native soil. Chambers were controlled to reproduce ambient or ambient +180 ppm CO2 and either ambient temperature or ambient +3.5 °C for 4 years. There were no significant CO2 × temperature interactions; consequently the data are presented for the CO2 and temperature effects. At the final harvest, elevated CO2 decreased the nonpolar fraction of the PCC and increased the polar fraction and amount of sugars in the needles. In contrast, elevated temperature increased the nonpolar fraction of the PCC and decreased sugars in needles. There were no CO2 or temperature effects on the PCC fractions in the woody tissue or root tissue. Elevated CO2 and temperature had no significant effects on the C content of any of the plant tissues or fractions. In contrast, the foliar N content declined under elevated CO2 and increased under elevated temperature; there were no significant effects in other tissues. The changes in the foliar N concentrations were in the cellulose and lignin fractions, the fractions, which contain protein, and are the consequences of changes in N allocation under the treatments. These results indicate reallocation of N among plant organs to optimize C assimilation, which is mediated via changes in the selectivity of Rubisco and carbohydrate modulation of gene expression. 相似文献
165.
PAUL R. WILLIAMS ROBERT A. CONGDON ANTHONY C. GRICE PETER J. CLARKE 《Austral ecology》2003,28(3):327-338
Abstract Changes in plant abundance within a eucalypt savanna of north‐eastern Australia were studied using a manipulative fire experiment. Three fire regimes were compared between 1997 and 2001: (i) control, savanna burnt in the mid‐dry season (July) 1997 only; (ii) early burnt, savanna burnt in the mid‐dry season 1997 and early dry season (May) 1999; and (iii) late burnt, savanna burnt in the mid‐dry season 1997 and late dry season (October) 1999. Five annual surveys of permanent plots detected stability in the abundance of most species, irrespective of fire regime. However, a significant increase in the abundance of several subshrubs, ephemeral and twining perennial forbs, and grasses occurred in the first year after fire, particularly after late dry season fires. The abundance of these species declined toward prefire levels in the second year after fire. The dominant grass Heteropogon triticeus significantly declined in abundance with fire intervals of 4 years. The density of trees (>2 m tall) significantly increased in the absence of fire for 4 years, because of the growth of saplings; and the basal area of the dominant tree Corymbia clarksoniana significantly increased over the 5‐year study, irrespective of fire regime. Conservation management of these savannas will need to balance the role of regular fires in maintaining the diversity of herbaceous species with the requirement of fire intervals of at least 4‐years for allowing the growth of saplings >2 m in height. Whereas late dry season fires may cause some tree mortality, the use of occasional late fires may help maintain sustainable populations of many grasses and forbs. 相似文献
166.
JOHANNES KAMP ROBERT D. SHELDON MAXIM A. KOSHKIN PAUL F. DONALD & ROBERT BIEDERMANN 《Ibis》2009,151(3):452-463
Habitat associations and distribution of breeding Sociable Lapwings were examined in 2004–2008 in central Kazakhstan to develop and assess hypotheses relating to the species' decline and high conservation threat status. At a landscape scale, breeding colonies were strongly positively associated with villages and rivers. Habitat suitability models had very high predictive power and suggested that only 6.6–8.0% of the 30 000-km2 study area was potentially suitable for Sociable Lapwings. Models developed to describe the spatial distribution of nests in one region of Kazakhstan in one year predicted well the distribution of nests in another region, suggesting good generality. At a colony scale, nests were most likely to be found in the most heavily grazed areas, with a high cover of animal dung and bare ground. Despite the low density of human settlements in the study area, most Sociable Lapwing nests were < 2 km from a village. Patterns of grazing were assessed by fitting GPS loggers to cattle. There was a strong positive correlation around villages between grazing intensity and the density of Sociable Lapwing nests, with clear evidence of a threshold of grazing density that needs to be reached before birds will breed. This high degree of synanthropy, perhaps unique in a critically endangered bird, is likely to result from post-Soviet changes in steppe management and offers both threats and opportunities to the species' conservation. 相似文献
167.
by C. R. C. PAUL 《Palaeontology》2009,52(3):485-489
Abstract: The fidelity of the fossil record reflects how accurately it preserves the history of life. Since Darwin's time any mismatch between our theories and the fossil record has been attributed to the imperfections of the record. For over a century scarcity of gradual evolutionary trends was explained in this way until the punctuated equilibrium model was proposed. A null hypothesis that all morphological patterns in the fossil record are unbiased random walks can be rejected because it predicts far more apparent trends than exist. Current best estimates suggest that trends occur in at most 5% of characters. When an organism dies either it becomes fossilized or it doesn't. To be confident a species has not been preserved the probability against preservation must be significantly larger than the total number of individuals of that species that ever existed. For skeletized species preservation was the norm not the exception. Nevertheless, fossils must then avoid subsequent destruction and be discovered to be useful. 相似文献
168.
ABSTRACT. In North America, zebra mussels ( Dreissena polymorpha ) are notoriously known as invasive species. The abundance of naked amoebae sampled from the shells of zebra mussels was compared with abundances from rock scrapings at approximately monthly intervals for 1 year. The sites were 2 km apart along the same shoreline. No significant difference in abundance of naked amoebae ( F =1.44; P ≤0.270) was detected for the two sampling sites. The combined data showed a minimum density of naked amoebae in winter, followed by peaks in early spring. The percent encysted increased from a low of 1% in the summer to 80% in early winter. 相似文献
169.
MICHAEL S. BALSHI † A. DAVID McGUIRE ‡ PAUL DUFFY§ MIKE FLANNIGAN¶ JOHN WALSH JERRY MELILLO 《Global Change Biology》2009,15(3):578-600
Fire is a common disturbance in the North American boreal forest that influences ecosystem structure and function. The temporal and spatial dynamics of fire are likely to be altered as climate continues to change. In this study, we ask the question: how will area burned in boreal North America by wildfire respond to future changes in climate? To evaluate this question, we developed temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5° (latitude × longitude) resolution using a Multivariate Adaptive Regression Spline (MARS) approach across Alaska and Canada. Burned area was substantially more predictable in the western portion of boreal North America than in eastern Canada. Burned area was also not very predictable in areas of substantial topographic relief and in areas along the transition between boreal forest and tundra. At the scale of Alaska and western Canada, the empirical fire models explain on the order of 82% of the variation in annual area burned for the period 1960–2002. July temperature was the most frequently occurring predictor across all models, but the fuel moisture codes for the months June through August (as a group) entered the models as the most important predictors of annual area burned. To predict changes in the temporal and spatial dynamics of fire under future climate, the empirical fire models used output from the Canadian Climate Center CGCM2 global climate model to predict annual area burned through the year 2100 across Alaska and western Canada. Relative to 1991–2000, the results suggest that average area burned per decade will double by 2041–2050 and will increase on the order of 3.5–5.5 times by the last decade of the 21st century. To improve the ability to better predict wildfire across Alaska and Canada, future research should focus on incorporating additional effects of long‐term and successional vegetation changes on area burned to account more fully for interactions among fire, climate, and vegetation dynamics. 相似文献
170.
GUTHRIE S. ZIMMERMAN TIMOTHY J. MOSER WILLIAM L. KENDALL PAUL F. DOHERTY JR. GARY C. WHITE DALE F. CASWELL 《The Journal of wildlife management》2009,73(5):710-719
ABSTRACT We assessed variation in reporting probabilities of standard bands among species, populations, harvest locations, and size classes of North American geese to enable estimation of unbiased harvest probabilities. We included reward (US$10, $20, $30, $50, or $100) and control ($0) banded geese from 16 recognized goose populations of 4 species: Canada (Branta canadensis), cackling (B. hutchinsii), Ross's (Chen rossii), and snow geese (C. caerulescens). We incorporated spatially explicit direct recoveries and live recaptures into a multinomial model to estimate reporting, harvest, and band-retention probabilities. We compared various models for estimating harvest probabilities at country (United States vs. Canada), flyway (5 administrative regions), and harvest area (i.e., flyways divided into northern and southern sections) scales. Mean reporting probability of standard bands was 0.73 (95% CI = 0.69–0.77). Point estimates of reporting probabilities for goose populations or spatial units varied from 0.52 to 0.93, but confidence intervals for individual estimates overlapped and model selection indicated that models with species, population, or spatial effects were less parsimonious than those without these effects. Our estimates were similar to recently reported estimates for mallards (Anas platyrhynchos). We provide current harvest probability estimates for these populations using our direct measures of reporting probability, improving the accuracy of previous estimates obtained from recovery probabilities alone. Goose managers and researchers throughout North America can use our reporting probabilities to correct recovery probabilities estimated from standard banding operations for deriving spatially explicit harvest probabilities. 相似文献