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   111441篇
  免费   3614篇
  国内免费   164篇
管理学   13755篇
劳动科学   60篇
民族学   1134篇
人才学   40篇
人口学   7852篇
丛书文集   5754篇
教育普及   2篇
理论方法论   10529篇
现状及发展   1篇
综合类   10032篇
社会学   45736篇
统计学   20324篇
  2023年   586篇
  2022年   532篇
  2021年   795篇
  2020年   1733篇
  2019年   2389篇
  2018年   2420篇
  2017年   3655篇
  2016年   2753篇
  2015年   2609篇
  2014年   3306篇
  2013年   19797篇
  2012年   3517篇
  2011年   3748篇
  2010年   3423篇
  2009年   3649篇
  2008年   3399篇
  2007年   3505篇
  2006年   3706篇
  2005年   3573篇
  2004年   2872篇
  2003年   2473篇
  2002年   2614篇
  2001年   2622篇
  2000年   2252篇
  1999年   2085篇
  1998年   1728篇
  1997年   1583篇
  1996年   1555篇
  1995年   1528篇
  1994年   1437篇
  1993年   1419篇
  1992年   1444篇
  1991年   1358篇
  1990年   1323篇
  1989年   1155篇
  1988年   1229篇
  1987年   1079篇
  1986年   988篇
  1985年   1168篇
  1984年   1208篇
  1983年   1083篇
  1982年   976篇
  1981年   889篇
  1980年   843篇
  1979年   930篇
  1978年   806篇
  1977年   729篇
  1976年   683篇
  1975年   651篇
  1974年   549篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
991.
The basic assumption underlying the concept of ranked set sampling is that actual measurement of units is expensive, whereas ranking is cheap. This may not be true in reality in certain cases where ranking may be moderately expensive. In such situations, based on total cost considerations, k-tuple ranked set sampling is known to be a viable alternative, where one selects k units (instead of one) from each ranked set. In this article, we consider estimation of the distribution function based on k-tuple ranked set samples when the cost of selecting and ranking units is not ignorable. We investigate estimation both in the balanced and unbalanced data case. Properties of the estimation procedure in the presence of ranking error are also investigated. Results of simulation studies as well as an application to a real data set are presented to illustrate some of the theoretical findings.  相似文献   
992.
This study examined the emergence of affect specificity in infancy. In this study, infants received verbal and facial signals of 2 different, negatively valenced emotions (fear and sadness) as well as neutral affect via a television monitor to determine if they could make qualitative distinctions among emotions of the same valence. Twenty 12‐ to 14‐month‐olds and 20 16‐ to 18‐month‐olds were examined. Results suggested that younger infants showed no evidence of referential specificity, as they responded similarly to both the target and distracter toys, and showed no evidence of affect specificity, showing no difference in play between affect conditions. Older infants, in contrast, showed evidence both of referential and affect specificity. With respect to affect specificity, 16‐ to 18‐month‐olds touched the target toy less in the fear condition than in the sad condition and showed a larger proportion of negative facial expressions in the sad condition versus the fear condition. These findings suggest a developmental emergence after 15 months of age for affect specificity in relating emotional messages to objects.  相似文献   
993.
Class theorists of embodiment in Sociology point to and illuminate both an over‐ and an under‐exposed body and experience that ultimately mark the bodies of the poor as ideologically, discursively and materially abject. In this essay, I map out theories of the bodies of the poor, including those of Marx, Engels, Elias, Bourdieu, Foucault, Donzelot and Adair. I suggest that an understanding of the ways in which the bodies of the poor are positioned as abject can facilitate a flexible and reflexive heuristic through which we can negotiate epistemic shifts between material and discursive categories, as well as providing us with a template through which we can come to understand even the most profoundly abject bodies, those of poor women in a welfare state, as potential sites of embodied agency and resistance, all central to the ethical and holistic study of sociology.  相似文献   
994.
This paper presents an argument for further engagement between educational scholars and school-based social justice activists. An analysis of one segment of the broad field of social justice education focuses on multicultural and antiracist education, particularly as they are understood in the Canadian socio-political context. A brief overview of the literature from UK and US sources highlights their complex and often overlapping concerns, and the need for more dialogue across national boundaries toward progressive social change. Excerpts from in-depth interviews with four Canadian teacher-activists reveal the potential for educators to take up various debates and findings from the academic literature in their daily struggles to work for social justice.  相似文献   
995.
本文概叙了入世后中国农业面临的农产品品质 安全性及价格的三重冲击和应采取的应对措施 着重分析了农产品安全问题和食品安全保障体系的构建 论述了分析测试技术和科学仪器的七项重任  相似文献   
996.
Summary. Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely used for sufficiently long for direct epidemiological studies to have high sensitivity for detecting any induced incidence of cancer, for example. The background and evidence are briefly reviewed and the steps taken in the UK to make information widely available described.  相似文献   
997.
Julia R. Irwin 《Infancy》2003,4(4):503-516
This study examined whether perceivers can detect infant distress in the visual and acoustic signals within the cry. Parent and nonparent perceivers rated distress in 3‐, 6‐, 8‐, and 12‐month‐old infants' cries that were manipulated to separate facial, vocal, and bodily action. Mean perceiver ratings differed for high‐ and low‐distress cries at each infant age on the basis of facial and vocal action, but not bodily movement. Perceivers rated the cry sound as more distressed and the cry face as less distressed with increasing infant age. Parents rated the cries as less distressed overall than did nonparents. The results suggest that information about distress is available for perceivers in the crying infant's face and voice.  相似文献   
998.
The Alchian and Allen theorem predicts that it will be harder to find "good" apples in the State of Washington, a prime apple-growing region, than in, say, New York City, where the addition of shipping charges makes "bad" apples comparatively more expensive. We recast the theorem as a testable proposition by explicitly taking the supply side into account and identifying plausible scenarios in which a fixed cost either has no effect on the relative prices of high and low quality grades of the same good in distant markets or, indeed, causes more of the bad apples to be shipped out.  相似文献   
999.
随着市场经济的发展 ,格式合同应用越来越普遍 ,随之带来的是法律对其规定的日益完善。文章通过对格式合同历史发展过程的简要分析 ,阐述了对格式合同的解释存在歧义时 ,应作不利于提供格式合同一方的解释 ,格式合同的条款无效的效力也限于提供合同的一方 ,另一方不承担相应的无效责任  相似文献   
1000.
农业是美国所有产业中竞争最激烈的产业之一 ,农业的激烈竞争主要是由进入“门槛”低所致。在 1981到 1990年期间 ,美国联邦政府花在农业上的补贴超过 2 50 0亿美元。价格补贴是美国农业保护政策的基础 ,成本补贴又使因价格补贴导致的市场过剩更加严重。对农民采取直接收入补贴政策的好处在于 :该政策能在不引起市场价格和农业产出扭曲的情况下 ,保证农民收入能达到一定水平  相似文献   
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