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   13986篇
  免费   388篇
管理学   2061篇
民族学   74篇
人才学   2篇
人口学   1420篇
丛书文集   86篇
教育普及   1篇
理论方法论   1243篇
现状及发展   1篇
综合类   168篇
社会学   6760篇
统计学   2558篇
  2023年   96篇
  2021年   86篇
  2020年   228篇
  2019年   295篇
  2018年   346篇
  2017年   479篇
  2016年   395篇
  2015年   261篇
  2014年   325篇
  2013年   2347篇
  2012年   499篇
  2011年   415篇
  2010年   326篇
  2009年   334篇
  2008年   362篇
  2007年   338篇
  2006年   319篇
  2005年   352篇
  2004年   328篇
  2003年   294篇
  2002年   325篇
  2001年   360篇
  2000年   351篇
  1999年   313篇
  1998年   217篇
  1997年   202篇
  1996年   208篇
  1995年   198篇
  1994年   165篇
  1993年   196篇
  1992年   204篇
  1991年   179篇
  1990年   178篇
  1989年   201篇
  1988年   172篇
  1987年   156篇
  1986年   169篇
  1985年   186篇
  1984年   195篇
  1983年   180篇
  1982年   147篇
  1981年   124篇
  1980年   120篇
  1979年   154篇
  1978年   99篇
  1977年   108篇
  1976年   96篇
  1975年   98篇
  1974年   97篇
  1973年   80篇
排序方式: 共有10000条查询结果,搜索用时 468 毫秒
101.
Summary.  To investigate the variability in energy output from a network of photovoltaic cells, solar radiation was recorded at 10 sites every 10 min in the Pentland Hills to the south of Edinburgh. We identify spatiotemporal auto-regressive moving average models as the most appropriate to address this problem. Although previously considered computationally prohibitive to work with, we show that by approximating using toroidal space and fitting by matching auto-correlations, calculations can be substantially reduced. We find that a first-order spatiotemporal auto-regressive (STAR(1)) process with a first-order neighbourhood structure and a Matern noise process provide an adequate fit to the data, and we demonstrate its use in simulating realizations of energy output.  相似文献   
102.
103.
104.
While body fat is the most accurate measure of obesity, its measurement requires special equipment that can be costly and time consuming to operate. Attention has thus typically focused on the easier to calculate body mass index (BMI). However, the ability of BMI to accurately identify obesity has been increasingly questioned. This paper focuses attention on whether more general body mass indices are appropriate measures of body fat. Using a data set of body fat, height, and weight measurements, general models are estimated which nest a wide variety of weight–height indices as special cases. In the absence of a race and gender categorisation, the conventional BMI was found to be the appropriate index with which to predict body fat. When such a categorisation was made, however, the BMI was never selected as the appropriate index. In general, predicted female body fat was some 10 kg higher than that of a male of identical build and predicted % body fat was over 11 percentage points higher, but age effects were smaller for females. Considerable racial differences in predicted body fat were found for males, but such differences were less marked for females. The implications of this finding for interpreting recent research on the effect of obesity on health, society, and economic factors are considered.  相似文献   
105.
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   
106.
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   
107.
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   
108.
109.
The moderating role of maternal characteristics and maternal sensitivity on the concordance between maternal reports and laboratory observations of negative emotionality was examined. Participants were 90 primiparous mothers and their infants. Mothers completed questionnaires about remembered care from their own parents and their depressive symptoms prenatally, infant temperament (distress to novelty and distress to limitations), and depressive symptoms postnatally. Mothers and infants participated in a laboratory assessment of infant temperament (distress to novelty and limitations) and maternal sensitivity at 6 months postpartum. Several factors that moderate the degree of concordance between maternal reports and behavioral observations were identified, as predicted. Novelty concordance was higher when mothers reported having their emotional needs met in childhood and low prenatal depressive symptoms. Limitations concordance was higher when mothers were less sensitive during the observational tasks. Methodological and theoretical implications are discussed.  相似文献   
110.
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