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151.
Hughes JF Skaletsky H Rozen S Wilson RK Page DC 《Nature genetics》2006,38(8):853-4; author reply 854-5
152.
This article explores recent trends in marriage. Following consistent falls in marriage rates in the last quarter of the 20th century the early years of this century have seen some relatively large fluctuations in marriage numbers and rates. This article illustrates some of the recent trends in marriage. One innovation is that it presents marriage data by month, controlled for the effect of peak marriage days in the week. It also discusses a recent legislative change, affecting those subject to immigration control that wish to marry, which may be one of many factors affecting latest marriage trends. Readers should bear in mind that the 2005 data shown in the article are provisional. 相似文献
153.
A QTL influencing F cell production maps to a gene encoding a zinc-finger protein on chromosome 2p15
Menzel S Garner C Gut I Matsuda F Yamaguchi M Heath S Foglio M Zelenika D Boland A Rooks H Best S Spector TD Farrall M Lathrop M Thein SL 《Nature genetics》2007,39(10):1197-1199
F cells measure the presence of fetal hemoglobin, a heritable quantitative trait in adults that accounts for substantial phenotypic diversity of sickle cell disease and beta thalassemia. We applied a genome-wide association mapping strategy to individuals with contrasting extreme trait values and mapped a new F cell quantitative trait locus to BCL11A, which encodes a zinc-finger protein, on chromosome 2p15. The 2p15 BCL11A quantitative trait locus accounts for 15.1% of the trait variance. 相似文献
154.
Most non‐linear techniques give good in‐sample fits to exchange rate data but are usually outperformed by random walks or random walks with drift when used for out‐of‐sample forecasting. In the case of regime‐switching models it is possible to understand why forecasts based on the true model can have higher mean squared error than those of a random walk or random walk with drift. In this paper we provide some analytical results for the case of a simple switching model, the segmented trend model. It requires only a small misclassification, when forecasting which regime the world will be in, to lose any advantage from knowing the correct model specification. To illustrate this we discuss some results for the DM/dollar exchange rate. We conjecture that the forecasting result is more general and describes limitations to the use of switching models for forecasting. This result has two implications. First, it questions the leading role of the random walk hypothesis for the spot exchange rate. Second, it suggests that the mean square error is not an appropriate way to evaluate forecast performance for non‐linear models. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
155.
Akiyoshi B Sarangapani KK Powers AF Nelson CR Reichow SL Arellano-Santoyo H Gonen T Ranish JA Asbury CL Biggins S 《Nature》2010,468(7323):576-579
Kinetochores are macromolecular machines that couple chromosomes to dynamic microtubule tips during cell division, thereby generating force to segregate the chromosomes. Accurate segregation depends on selective stabilization of correct 'bi-oriented' kinetochore-microtubule attachments, which come under tension as the result of opposing forces exerted by microtubules. Tension is thought to stabilize these bi-oriented attachments indirectly, by suppressing the destabilizing activity of a kinase, Aurora B. However, a complete mechanistic understanding of the role of tension requires reconstitution of kinetochore-microtubule attachments for biochemical and biophysical analyses in vitro. Here we show that native kinetochore particles retaining the majority of kinetochore proteins can be purified from budding yeast and used to reconstitute dynamic microtubule attachments. Individual kinetochore particles maintain load-bearing associations with assembling and disassembling ends of single microtubules for >30?min, providing a close match to the persistent coupling seen in vivo between budding yeast kinetochores and single microtubules. Moreover, tension increases the lifetimes of the reconstituted attachments directly, through a catch bond-like mechanism that does not require Aurora B. On the basis of these findings, we propose that tension selectively stabilizes proper kinetochore-microtubule attachments in vivo through a combination of direct mechanical stabilization and tension-dependent phosphoregulation. 相似文献
156.
It is well documented that the generations born around 1930 are consistently exhibiting higher rates of mortality improvement than the generations either side of them. There is currently no evidence that these differentials are declining. In current ONS National Population Projections, it is assumed that these cohorts will continue to experience higher rates of improvement. However, it is not yet precisely clear why this is so. This article details preliminary research carried out using the ONS Longitudinal Study to try to understand better why the members of the generation born around 1930 have been enjoying higher rates of mortality improvement throughout their adult life. 相似文献
157.
Geothermal energy potential is usually discussed in the context of conventional or engi-neered systems and at the scale of an individual reservoir. Whereas exploration for conventional reser-voirs has ... 相似文献
158.
The structure of grassland communities can vary widely in response to heterogeneous habitat variables. In this study we document plant communities, soil types, and site characteristics for 12 Palouse prairie remnants in southeastern Washington and northern Idaho. We used general linear models to test the predictive value of 6 biophysical variables (slope, aspect, distance from edge, edge type, vegetation structure, and soil type) on 3 plant community metrics: species richness, Simpson’s diversity index, and the dominance of exotic species. From full models including all variables, we used Akaike’s information criterion (AIC) to select the best model for each metric. Aspect and vegetation structure were significant predictors of species richness ( R 2 = 0.08) and diversity ( R 2 = 0.09), while aspect, soil type, distance from edge, and edge type (type of adjacent matrix habitat) influenced the dominance of exotic species ( R 2 = 0.28). Additional soil sampling determined that the depth to a restrictive layer also had significant impacts on the dominance of exotic species ( R 2 = 0.31). This study confirms that biophysical characteristics influence Palouse prairie plant communities and may help set research and conservation priorities for isolated and uninventoried remnants. 相似文献
159.
Even though cohabitation has become more prevalent in the last few decades, the majority of the adult population is married, and marriage is associated with a number of factors, such as educational outcom and health. Understanding the marrie population is also an important part of understanding partnering behaviour and family formation and dissolution. The length of marriages and whether they are ended by death or divorce is therefore of interest t demographers and policy maker 相似文献
160.
Barton A Thomson W Ke X Eyre S Hinks A Bowes J Plant D Gibbons LJ;Wellcome Trust Case Control Consortium;YEAR Consortium;BIRAC Consortium Wilson AG Bax DE Morgan AW Emery P Steer S Hocking L Reid DM Wordsworth P Harrison P Worthington J 《Nature genetics》2008,40(10):1156-1159
The WTCCC study identified 49 SNPs putatively associated with rheumatoid arthritis at P = 1 x 10(-4) - 1 x 10(-5) (tier 3). Here we show that three of these SNPs, mapping to chromosome 10p15 (rs4750316), 12q13 (rs1678542) and 22q13 (rs3218253), are also associated (trend P = 4 x 10(-5), P = 4 x 10(-4) and P = 4 x 10(-4), respectively) in a validation study of 4,106 individuals with rheumatoid arthritis and an expanded reference group of 11,238 subjects, confirming them as true susceptibility loci in individuals of European ancestry. 相似文献