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   10645篇
  免费   301篇
  国内免费   2篇
管理学   1492篇
民族学   63篇
人才学   3篇
人口学   963篇
丛书文集   70篇
理论方法论   1075篇
综合类   225篇
社会学   5476篇
统计学   1581篇
  2020年   152篇
  2019年   249篇
  2018年   261篇
  2017年   371篇
  2016年   260篇
  2015年   199篇
  2014年   253篇
  2013年   1736篇
  2012年   351篇
  2011年   338篇
  2010年   271篇
  2009年   261篇
  2008年   250篇
  2007年   291篇
  2006年   261篇
  2005年   264篇
  2004年   244篇
  2003年   178篇
  2002年   214篇
  2001年   274篇
  2000年   231篇
  1999年   210篇
  1998年   168篇
  1997年   157篇
  1996年   154篇
  1995年   144篇
  1994年   149篇
  1993年   149篇
  1992年   151篇
  1991年   148篇
  1990年   152篇
  1989年   147篇
  1988年   133篇
  1987年   148篇
  1986年   116篇
  1985年   147篇
  1984年   156篇
  1983年   141篇
  1982年   123篇
  1981年   89篇
  1980年   111篇
  1979年   113篇
  1978年   102篇
  1977年   86篇
  1976年   88篇
  1975年   99篇
  1974年   94篇
  1973年   69篇
  1972年   61篇
  1971年   53篇
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
261.
“Cruising” infants can only walk using external support to augment their balance. We examined cruisers' understanding of support for upright locomotion under four conditions: cruising over a wooden handrail at chest height, a large gap in the handrail, a wobbly unstable handrail, and an ill‐positioned low handrail. Infants distinguished among the support properties of the handrails with differential attempts to cruise and handrail‐specific forms of haptic exploration and gait modifications. They consistently attempted the wood handrail, rarely attempted the gap, and occasionally attempted the low and wobbly handrails. On the wood and gap handrails, attempt rates matched the probability of cruising successfully, but on the low and wobbly handrails, attempt rates under‐ and overestimated the probability of success, respectively. Haptic exploration was most frequent and varied on the wobbly handrail, and gait modifications—including previously undocumented “knee cruising”—were most frequent and effective on the low handrail. Results are discussed in terms of developmental changes in the meaning of support.  相似文献   
262.
This article provides an overview of sociological research on three aspects of feminism: feminism as an ideology; feminism as an identity; and feminism as a practice. I summarize the main contributions of sociological research in each of these areas, and highlight the overarching contributions for understanding contemporary feminism. Three contributions are key. First, sociological research highlights the existence multiple varieties of feminism –“feminisms” as opposed to a singular “feminism.” Second, this research reveals that feminist ideologies, identities, and movements are each dynamic – they have changed historically, and continue to change in response to shifting socio‐political, economic, and technological landscapes. Third, sociological research demonstrates that feminism is alive and well, and in many senses thriving, in the contemporary United States. Though some aspects of feminism are more widespread than others, sociological research challenges the notion that feminism, on the whole, has declined. As an ideology, an identity, and a practice, feminism remains strong in the contemporary United States.  相似文献   
263.
264.
There are hundreds of thousands of children in foster care in the United States, nearly a majority of whom are placed with nonrelative foster parents (U.S. Department of Health and Human Services, 2015). Few scholars (e.g., Nelson, 2014) have explored the communicative process through which a sense of family is created and maintained in foster families, despite the potential positive impact that developing a foster family identity may have on foster family functioning. The purpose of the present study was to understand the communicative strategies that foster parents use to create family identity. Data from interviews with 18 current and former foster parents revealed that through their talk inside and outside of the family, foster parents engaged in integrating biological and foster families, ritualizing, explaining, labeling family roles, and reframing. I discuss the importance of these findings for foster families.  相似文献   
265.
Emotions in the workplace influence a number of critical cognitive tasks including information processing and decision-making. Moreover, the effect of emotion on these operations is often emotion-specific. Given these unique effects, leaders may need to learn how to manage subordinates' discrete emotions, and not just general affect. This laboratory experiment examined the effects of leaders suggesting different regulation strategies after subordinates experienced anger or pessimism. Effects of these emotions under different leader-facilitated regulation strategies were evaluated with respect to planning, a critical organizational task, and perceptions of leader effectiveness. Results demonstrated that the type of leader-facilitated regulation strategy moderates the relationships of anger and pessimism to planning. The findings imply that leaders should understand the differential effects of discrete emotions, and be prepared to help subordinates manage emotions accordingly.  相似文献   
266.
267.
Small area statistics obtained from sample survey data provide a critical source of information used to study health, economic, and sociological trends. However, most large-scale sample surveys are not designed for the purpose of producing small area statistics. Moreover, data disseminators are prevented from releasing public-use microdata for small geographic areas for disclosure reasons; thus, limiting the utility of the data they collect. This research evaluates a synthetic data method, intended for data disseminators, for releasing public-use microdata for small geographic areas based on complex sample survey data. The method replaces all observed survey values with synthetic (or imputed) values generated from a hierarchical Bayesian model that explicitly accounts for complex sample design features, including stratification, clustering, and sampling weights. The method is applied to restricted microdata from the National Health Interview Survey and synthetic data are generated for both sampled and non-sampled small areas. The analytic validity of the resulting small area inferences is assessed by direct comparison with the actual data, a simulation study, and a cross-validation study.  相似文献   
268.
Social Indicators Research - The registers of Dublin’s parishes in the seventeenth century provide access to aspects of civic and religious life. In the registers are records of burials,...  相似文献   
269.
Lawns are considered monocultures and lesser contributors to sustainability than diverse nature but are still a dominating green area feature and an important cultural phenomenon in cities. Lawns have esthetical values, provide playground, are potential habitat for species, contribute to carbon sequestration and water infiltration, but also increase pesticides, fertilization, are monocultures and costly to manage at the same time. To evaluate the potential impact of lawns, whether positive or negative, it is of interest to estimate the total lawn cover in cities and its change over time. This is not a straightforward process, e.g., because many lawns are small and covered by trees. In this study we review the existing literature of lawn cover in cities and the different methodologies used for cover estimation. We found both pros and cons with NDVI and LiDAR data as well as manually interpreted aerial photos. The total cover of lawns in three case study cities was estimated to 22.5%. By extrapolating these percentages to all Swedish cities lawn cover was estimated to 2589 km2 (0.6% of the terrestrial surface). The approximated total municipal management cost of lawns in all Swedish cities was 910,000,000 USD/ year. During 50 years lawn area almost doubled in relative cover and 56% of them were continuously managed. Since lawns constitute large parts of the urban greenery and are costly to manage it is highly relevant to consider their social, ecological and cultural value compared to alternatives, e.g., meadows with less intensive management.  相似文献   
270.
This article compares the mean-squared error (or ?2 risk) of ordinary least squares (OLS), James–Stein, and least absolute shrinkage and selection operator (Lasso) shrinkage estimators in simple linear regression where the number of regressors is smaller than the sample size. We compare and contrast the known risk bounds for these estimators, which shows that neither James–Stein nor Lasso uniformly dominates the other. We investigate the finite sample risk using a simple simulation experiment. We find that the risk of Lasso estimation is particularly sensitive to coefficient parameterization, and for a significant portion of the parameter space Lasso has higher mean-squared error than OLS. This investigation suggests that there are potential pitfalls arising with Lasso estimation, and simulation studies need to be more attentive to careful exploration of the parameter space.  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