首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2088篇
  免费   45篇
管理学   299篇
民族学   14篇
人才学   1篇
人口学   194篇
丛书文集   5篇
理论方法论   252篇
综合类   20篇
社会学   1067篇
统计学   281篇
  2023年   17篇
  2022年   8篇
  2021年   21篇
  2020年   39篇
  2019年   57篇
  2018年   48篇
  2017年   75篇
  2016年   85篇
  2015年   52篇
  2014年   52篇
  2013年   285篇
  2012年   98篇
  2011年   88篇
  2010年   65篇
  2009年   67篇
  2008年   66篇
  2007年   97篇
  2006年   78篇
  2005年   70篇
  2004年   72篇
  2003年   64篇
  2002年   53篇
  2001年   54篇
  2000年   45篇
  1999年   52篇
  1998年   32篇
  1997年   19篇
  1996年   29篇
  1995年   21篇
  1994年   26篇
  1993年   14篇
  1992年   26篇
  1991年   21篇
  1990年   18篇
  1989年   19篇
  1988年   18篇
  1987年   13篇
  1986年   20篇
  1985年   13篇
  1984年   11篇
  1983年   15篇
  1982年   15篇
  1981年   8篇
  1980年   13篇
  1979年   19篇
  1978年   11篇
  1976年   5篇
  1975年   5篇
  1974年   7篇
  1964年   3篇
排序方式: 共有2133条查询结果,搜索用时 15 毫秒
111.
本文通过对马克思有关现代主义的观点进行深刻的文本学分析,得出如下结论:如果我们将自我决定和自由代理作为基本的人类能力,就没有理由解释为什么它只能得到个人主义的运用,确实有很多理由使我们认为在集体中它才能得到最好的实现,离开了这一点,全部的自由的自我决定便会停止.没有理由认为这种集体代理比个体选择缺少现代感.  相似文献   
112.
Mayer  Martin  Sunde  Peter 《Urban Ecosystems》2020,23(3):543-554

Despite the accelerating global urbanization and its associated implications for wildlife and humans, we know little about the biology of urban ecosystems. Here, we investigated colonization and habitat selection of the European hare (Lepus europaeus), a declining farmland species, in urban areas in Denmark, using a combination of citizen science data and transect counts. Further, we estimated the population density of urban hares in Aarhus, Denmark’s second largest city. Our results provide the first evidence that hares have established populations in urban areas, potentially in response to decreasing habitat quality in rural areas due to agricultural intensification. The hare density in Aarhus was ca. 8 hares per km2, which is comparable to or slightly higher than hare abundance estimates from various pastural areas in Europe, suggesting that urban areas provide suitable habitat for hares. Hare habitat selection was generally associated with areas consisting of large lawns, such as high buildings and parks, which potentially provide high-quality forage throughout the year. Considering the increasing expansion of urban areas and deteriorating habitat quality of agricultural areas, urban planning that incorporates habitat requirements for wildlife could help to support urban animal populations, especially for species of conservation concern.

  相似文献   
113.

For large cohort studies with rare outcomes, the nested case-control design only requires data collection of small subsets of the individuals at risk. These are typically randomly sampled at the observed event times and a weighted, stratified analysis takes over the role of the full cohort analysis. Motivated by observational studies on the impact of hospital-acquired infection on hospital stay outcome, we are interested in situations, where not necessarily the outcome is rare, but time-dependent exposure such as the occurrence of an adverse event or disease progression is. Using the counting process formulation of general nested case-control designs, we propose three sampling schemes where not all commonly observed outcomes need to be included in the analysis. Rather, inclusion probabilities may be time-dependent and may even depend on the past sampling and exposure history. A bootstrap analysis of a full cohort data set from hospital epidemiology allows us to investigate the practical utility of the proposed sampling schemes in comparison to a full cohort analysis and a too simple application of the nested case-control design, if the outcome is not rare.

  相似文献   
114.
ABSTRACT

Despite decades of equity- and inclusion-oriented discourse and reform in mathematics education, Black learners in the U.S. continue to experience dehumanizing and violent forms of mathematics education. I suggest that equity for Black learners in mathematics education is a delusion rooted in the fictions of white imaginaries, contingent on appeasing white logics and sensitivities, and characterized at best by incremental changes that do little to threaten the maintenance of racial hierarchies inside or outside of mathematics education. Moreover, the forms of inclusion offered up in equity-oriented discourses and reforms represent contexts of containment and enclosure that keep Black people in their same relative position. Refusal is suggested as a strategy for Black learners to resist the anti-Black character of mathematics education, and as a first step in actualizing forms of mathematics education that are worthy of Black learners.  相似文献   
115.
116.
This paper outlines decomposition methods for assessing how exposure affects prevalence and cumulative relative risk. Let     x     denote a vector of exogenous covariates and suppose that a single dimension of time   t   governs two event processes     T 1  and   T 2.    If the occurrence of the event     T 1    determines entry into the risk of the event     T 2,    then subgroup variation in     T 1    will affect the prevalence     T 2,    even if subgroups in the population are otherwise identical. Although researchers often acknowledge this phenomenon, the literature has not provided procedures to assess the magnitude of an exposure effect of     T 1    on the prevalence of     T 2.    We derive decompositions that assess how variation in exposure generated by direct and indirect effects of the covariates     x     affect measures of absolute and relative prevalence of     T 2.    We employ a parametric but highly flexible specification for baseline hazard for the     T 1  and   T 2    processes and use the resulting parametric proportional hazard model to illustrate the direct and indirect effects of family structure when     T 1    is age at first sexual intercourse and     T 2    is age at a premarital first birth for data on a cohort of non-hispanic white U.S. women.  相似文献   
117.
Bisphenol A (BPA) is an endocrine disrupting chemical that is found in human urine throughout industrial societies around the globe. Consumer exposure pathways to BPA include packaged food, household dust, air, and dental fillings. To date, information on the relative contribution of the different pathways to total consumer exposure is lacking, but is key for managing substance‐associated risks. We investigated the relative contributions of the pathways known to be most relevant for nine different consumer groups. Our results suggest that the most important pathways for infants and children are the use of polycarbonate (PC) baby bottles and for adults and teenagers the consumption of canned food. Dental surgery can also considerably contribute over a short time directly after the surgery. For infants fed with PC baby bottles with mean dose rates of 0.8 μg/kgbw/d the highest exposure dose rate was calculated. This dose rate is far below the tolerable daily intake of 50 μg/kgbw/d. However, it is of the same order of magnitude as recently reported concentrations that caused low‐dose health effects in rodents. We find a pattern of falling exposure levels with rising age that is supported by urinary concentrations of BPA available for selected consumer groups. Similarly, the exposure levels we predict are confirmed by the levels reported in these studies.  相似文献   
118.
This paper presents a hybrid genetic algorithm/mathematical programming heuristic for the n-job, m-machine flowshop problems with lot streaming. The number of sublots for each job and the size of sublots are directly addressed by the heuristic and setups may be sequence-dependent. A new aspect of the problem, the interleaving of sublots from different jobs in the processing sequence, is developed and addressed. Computational results from 12 randomly generated test sets of 24 problems each are presented.  相似文献   
119.
Stochastic scenario trees are a new and popular method by which surveillance systems can be analyzed to demonstrate freedom from pests and disease. For multiple component systems—such as a combination of a serological survey and systematically collected observations—it can be difficult to represent the complete system in a tree because many branches are required to represent complex conditional relationships. Here we show that many of the branches of some scenario trees have identical outcomes and are therefore redundant. We demonstrate how to prune branches and derive compact representations of scenario trees using matrix algebra and Bayesian belief networks. The Bayesian network representation is particularly useful for calculation and exposition. It therefore provides a firm basis for arguing disease freedom in international forums.  相似文献   
120.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号