全文获取类型
收费全文 | 4986篇 |
免费 | 187篇 |
专业分类
管理学 | 806篇 |
民族学 | 37篇 |
人才学 | 4篇 |
人口学 | 371篇 |
丛书文集 | 32篇 |
理论方法论 | 516篇 |
综合类 | 41篇 |
社会学 | 2607篇 |
统计学 | 759篇 |
出版年
2023年 | 35篇 |
2021年 | 28篇 |
2020年 | 85篇 |
2019年 | 139篇 |
2018年 | 124篇 |
2017年 | 156篇 |
2016年 | 139篇 |
2015年 | 128篇 |
2014年 | 143篇 |
2013年 | 845篇 |
2012年 | 187篇 |
2011年 | 158篇 |
2010年 | 148篇 |
2009年 | 142篇 |
2008年 | 168篇 |
2007年 | 150篇 |
2006年 | 176篇 |
2005年 | 181篇 |
2004年 | 153篇 |
2003年 | 146篇 |
2002年 | 134篇 |
2001年 | 116篇 |
2000年 | 86篇 |
1999年 | 104篇 |
1998年 | 76篇 |
1997年 | 58篇 |
1996年 | 58篇 |
1995年 | 45篇 |
1994年 | 80篇 |
1993年 | 61篇 |
1992年 | 64篇 |
1991年 | 68篇 |
1990年 | 65篇 |
1989年 | 56篇 |
1988年 | 57篇 |
1987年 | 48篇 |
1986年 | 40篇 |
1985年 | 55篇 |
1984年 | 63篇 |
1983年 | 49篇 |
1982年 | 49篇 |
1981年 | 36篇 |
1980年 | 22篇 |
1979年 | 28篇 |
1978年 | 31篇 |
1977年 | 23篇 |
1976年 | 27篇 |
1975年 | 21篇 |
1974年 | 21篇 |
1973年 | 19篇 |
排序方式: 共有5173条查询结果,搜索用时 250 毫秒
101.
Parody news programs regale viewers with satirical, witty, and humorous exposés of the political world and news coverage, but they have also been criticized for creating cynicism and political disengagement. This study found that parody news viewers are self-efficacious and more politically active than viewers of CNN, Fox News, MSNBC, or broadcast television news. Moreover, reliance on parody news shows does not lead to political polarization or government distrust. 相似文献
102.
Erin Trouth Hofmann Paul Jacobs Peggy Petrzelka 《International migration (Geneva, Switzerland)》2019,57(1):109-126
US states are active in enacting immigration policies, which vary widely and have substantial impact on the lives of immigrants. Our understanding of what produces these divergent state laws remains limited. Qualitative research demonstrates the importance of a 2010 immigration compact, supported by a powerful religious organization, in shaping immigration policies in Utah, and the Utah Compact was held up as a model for other states. But is the experience of Utah applicable across other states? We test the effects of compacts and interest groups on immigration policy adoption across all 50 states between 2005 and 2013. Our findings suggest that compacts are actually associated with more restrictive immigration policy. Although states with compacts are more likely to pass inclusive immigration laws, these are counterbalanced by higher numbers of exclusive laws. Both religious and non‐religious interests groups are associated with policy, but they do not explain the effects of compacts. 相似文献
103.
104.
Babak Shahbaba Shiwei Lan Wesley O. Johnson Radford M. Neal 《Statistics and Computing》2014,24(3):339-349
We show how the Hamiltonian Monte Carlo algorithm can sometimes be speeded up by “splitting” the Hamiltonian in a way that allows much of the movement around the state space to be done at low computational cost. One context where this is possible is when the log density of the distribution of interest (the potential energy function) can be written as the log of a Gaussian density, which is a quadratic function, plus a slowly-varying function. Hamiltonian dynamics for quadratic energy functions can be analytically solved. With the splitting technique, only the slowly-varying part of the energy needs to be handled numerically, and this can be done with a larger stepsize (and hence fewer steps) than would be necessary with a direct simulation of the dynamics. Another context where splitting helps is when the most important terms of the potential energy function and its gradient can be evaluated quickly, with only a slowly-varying part requiring costly computations. With splitting, the quick portion can be handled with a small stepsize, while the costly portion uses a larger stepsize. We show that both of these splitting approaches can reduce the computational cost of sampling from the posterior distribution for a logistic regression model, using either a Gaussian approximation centered on the posterior mode, or a Hamiltonian split into a term that depends on only a small number of critical cases, and another term that involves the larger number of cases whose influence on the posterior distribution is small. 相似文献
105.
Panos G. Georgopoulos Christopher J. Brinkerhoff Sastry Isukapalli Michael Dellarco Philip J. Landrigan Paul J. Lioy 《Risk analysis》2014,34(7):1299-1316
A challenge for large‐scale environmental health investigations such as the National Children's Study (NCS), is characterizing exposures to multiple, co‐occurring chemical agents with varying spatiotemporal concentrations and consequences modulated by biochemical, physiological, behavioral, socioeconomic, and environmental factors. Such investigations can benefit from systematic retrieval, analysis, and integration of diverse extant information on both contaminant patterns and exposure‐relevant factors. This requires development, evaluation, and deployment of informatics methods that support flexible access and analysis of multiattribute data across multiple spatiotemporal scales. A new “Tiered Exposure Ranking” (TiER) framework, developed to support various aspects of risk‐relevant exposure characterization, is described here, with examples demonstrating its application to the NCS. TiER utilizes advances in informatics computational methods, extant database content and availability, and integrative environmental/exposure/biological modeling to support both “discovery‐driven” and “hypothesis‐driven” analyses. “Tier 1” applications focus on “exposomic” pattern recognition for extracting information from multidimensional data sets, whereas second and higher tier applications utilize mechanistic models to develop risk‐relevant exposure metrics for populations and individuals. In this article, “tier 1” applications of TiER explore identification of potentially causative associations among risk factors, for prioritizing further studies, by considering publicly available demographic/socioeconomic, behavioral, and environmental data in relation to two health endpoints (preterm birth and low birth weight). A “tier 2” application develops estimates of pollutant mixture inhalation exposure indices for NCS counties, formulated to support risk characterization for these endpoints. Applications of TiER demonstrate the feasibility of developing risk‐relevant exposure characterizations for pollutants using extant environmental and demographic/socioeconomic data. 相似文献
106.
William B. Vessey Jamie D. Barrett Michael D. Mumford Genevieve Johnson Brett Litwiller 《The Leadership Quarterly》2014,25(4):672-691
In recent years there has been a marked increase in the study of the influence of leadership on creativity, and the effects of this relationship on organizational performance. While a number of explanations have been broached with regard to the positive effects of leadership on creativity, many of these studies propose different, and often contradictory, methods for leaders to achieve these positive effects on creativity within their organizations and work groups. Additionally, little work has been done examining the effects of leadership on highly creative people in fields requiring creativity. The purpose of this study is to examine two existing leadership theories with regard to their viability as models to explain creative performance of eminent scientists. Eminent scientists represent a population of leaders of highly creative individuals in a field that values the production of innovative ideas and products as a marker of performance. Ninety-three excerpts from the biographies of scientists were content coded for leader behaviors and performance criteria. The results of this analysis indicate that a model based on strategic planning and product championing may serve to explain the positive effects of leadership on creativity in a highly creative population. 相似文献
107.
108.
Lifetime Data Analysis - The recurrent/terminal event data structure has undergone considerable methodological development in the last 10–15 years. An example of the data structure that has... 相似文献
109.
Major Accidents (Gray Swans) Likelihood Modeling Using Accident Precursors and Approximate Reasoning 下载免费PDF全文
Compared to the remarkable progress in risk analysis of normal accidents, the risk analysis of major accidents has not been so well‐established, partly due to the complexity of such accidents and partly due to low probabilities involved. The issue of low probabilities normally arises from the scarcity of major accidents’ relevant data since such accidents are few and far between. In this work, knowing that major accidents are frequently preceded by accident precursors, a novel precursor‐based methodology has been developed for likelihood modeling of major accidents in critical infrastructures based on a unique combination of accident precursor data, information theory, and approximate reasoning. For this purpose, we have introduced an innovative application of information analysis to identify the most informative near accident of a major accident. The observed data of the near accident were then used to establish predictive scenarios to foresee the occurrence of the major accident. We verified the methodology using offshore blowouts in the Gulf of Mexico, and then demonstrated its application to dam breaches in the United Sates. 相似文献
110.
Demography - One of the most consistent patterns in the social sciences is the relationship between sibship size and educational outcomes: those with fewer siblings outperform those with many. The... 相似文献