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11.
This study examined reciprocal support networks involving extended family, friends and church members among African Americans. Our analysis examined specific patterns of reciprocal support (i.e., received only, gave only, both gave and received, neither gave or received), as well as network characteristics (i.e., contact and subjective closeness) as correlates of reciprocal support. The analysis is based on the African American subsample of the National Survey of American Life. Overall, our findings indicate that African Americans are very involved in reciprocal support networks with their extended family, friends and church members. Respondents were most extensively involved in reciprocal supports with extended family members, followed closely by friends and church networks. Network characteristics (i.e., contact and subjective closeness) were significantly and consistently associated with involvement with reciprocal support exchanges for all three networks. These and other findings are discussed in detail. This study complements previous work on the complementary roles of family, friend and congregational support networks, as well as studies of racial differences in informal support networks.  相似文献   
12.
Using networks as prior knowledge to guide model selection is a way to reach structured sparsity. In particular, the fused lasso that was originally designed to penalize differences of coefficients corresponding to successive features has been generalized to handle features whose effects are structured according to a given network. As any prior information, the network provided in the penalty may contain misleading edges that connect coefficients whose difference is not zero, and the extent to which the performance of the method depend on the suitability of the graph has never been clearly assessed. In this work we investigate the theoretical and empirical properties of the adaptive generalized fused lasso in the context of generalized linear models. In the fixed \(p\) setting, we show that, asymptotically, adding misleading edges in the graph does not prevent the adaptive generalized fused lasso from enjoying asymptotic oracle properties, while forgetting suitable edges can be more problematic. These theoretical results are complemented by an extensive simulation study that assesses the robustness of the adaptive generalized fused lasso against misspecification of the network as well as its applicability when theoretical coefficients are not exactly equal. Our contribution is also to evaluate the applicability of the generalized fused lasso for the joint modeling of multiple sparse regression functions. Illustrations are provided on two real data examples.  相似文献   
13.
The article discusses the nature of the tangled interaction between the ex-Soviet Central Asian republics and the outside great powers – Russia, the United States and China. Although the so-called Great Game model is often used to explain the geopolitical rivalry in the region, the current pattern of relations between various international actors is much more complex than a traditional tug-of-war between the old colonial empires. While Russia's strategic role in Central Asia appears to be on the rise, the capacity of the West to influence political developments in the region has diminished. However, the overall situation in Central Asia remains volatile and its geopolitical landscape is far from being settled.  相似文献   
14.
Demographic and Health Survey data from nine African countries make it clear that HIV/AIDS prevention knowledge has been increasing. Still, in many cases, fewer than half of adult respondents can identify specific prevention behaviors. Knowledge is lowest in rural areas and among women. HIV testing generally remains rare but is highly variable across countries, likely reflecting differences in the supply of testing services. In most cases, schooling and wealth impacts on prevention knowledge have either been stable or have increased; hence, in the majority of contexts, initial disparities in knowledge by education and wealth levels have persisted or widened.
David E. SahnEmail:
  相似文献   
15.
This paper examines recent changes in weekly income levels and dispersion for Māori, New Zealand’s indigenous ethnic group. Changes in the Māori income distribution between 1997 and 2003 reflect rapid increases in economic growth and employment rate. A reduced proportion of people had zero or benefit-level incomes and a higher proportion had high incomes. Income inequality declined for working-aged Māori and was stable for employed Māori. The average income gap between Māori and Europeans declined. The increased Māori employment rate during this period was the single most important driver of changes in the Māori income distribution.
David C. Maré (Corresponding author)Email:
  相似文献   
16.
Previous research shows that living in a non-intact family is associated with educational disadvantages. This paper compares the relationships between childhood family structure, schooling, and earnings in Sweden and the USA. This comparison is interesting because both family structure and public policies differ significantly. We find a negative relationship between living in a non-intact family and child outcomes, and the estimates are remarkably similar in both countries. After using sibling-difference models, the correlation with family structure is no longer significant. These results cast doubt on the causal interpretation of the negative relationship between non-intact family structures and child outcomes.  相似文献   
17.
资本主义经济危机与周期的理论 ,是马克思主义政治经济学中固有的理论。对这一理论的研究 ,已逐渐延伸到对社会经济发展过程中一般周期性波动问题的探讨。人类经济的发展 ,是否也呈现一定的周期性 ?本文试图说明 ,人类经济历史发展过程 ,是沿着某种曲折的波形路径推进的  相似文献   
18.
In confirmatory clinical trials, the prespecification of the primary analysis model is a universally accepted scientific principle to allow strict control of the type I error. Consequently, both the ICH E9 guideline and the European Medicines Agency (EMA) guideline on missing data in confirmatory clinical trials require that the primary analysis model is defined unambiguously. This requirement applies to mixed models for longitudinal data handling missing data implicitly. To evaluate the compliance with the EMA guideline, we evaluated the model specifications in those clinical study protocols from development phases II and III submitted between 2015 and 2018 to the Ethics Committee at Hannover Medical School under the German Medicinal Products Act, which planned to use a mixed model for longitudinal data in the confirmatory testing strategy. Overall, 39 trials from different types of sponsors and a wide range of therapeutic areas were evaluated. While nearly all protocols specify the fixed and random effects of the analysis model (95%), only 77% give the structure of the covariance matrix used for modeling the repeated measurements. Moreover, the testing method (36%), the estimation method (28%), the computation method (3%), and the fallback strategy (18%) are given by less than half the study protocols. Subgroup analyses indicate that these findings are universal and not specific to clinical trial phases or size of company. Altogether, our results show that guideline compliance is to various degrees poor and consequently, strict type I error rate control at the intended level is not guaranteed.  相似文献   
19.
What role does the body play in facilitating interaction across status differences? Whereas previous scholarly work has focused on “roles” and “specialized knowledge,” I investigate how bodies, appearances, and physical abilities are also consequential in these exchanges through the concept of “bodily capital.” Coined by Bourdieu, bodily capital provides a way to understand why individuals invest time, energy, and resources into their bodies, and what they expect to receive in return. As a concept, bodily capital is necessarily broad as it encompasses a variety of forms, including athletic prowess, attractiveness, physique, muscle tone/strength, agility, and other modes of embodiment. Because the body is integral to a variety of status distinction-making processes, individuals invest in and exchange bodily capital to increase their relative status in specific fields. Drawing on interviews with 26 personal trainers and 25 clients, as well as more than one year of participant observation, I find that trainers and clients use bodily capital to negotiate gender and age differences, either by re-arranging interactional power dynamics or resisting stereotypes. The type of bodily capital that allows for such negotiations to take place, however, is the hegemonic thin-toned ideal—a classed and largely raced form of bodily capital that has purchase in the U.S. fitness industry. Although individuals in the study were able to use this form of capital to enable successful cross-status interactions, doing so reified the dominance of middle-class, white bodily aesthetics. Thus, while bodily capital may challenge some status hierarchies, it reinforces others.  相似文献   
20.
In this analysis, I examine the effects of community-level volunteering on an individual’s choices regarding time – whether to work and whether to volunteer. In order to better explain the decision to volunteer, a classic pure public goods structure is contrasted with a less restrictive impure public goods model that admits other possible private motivations. The results of this study undermine the neoclassical notion that volunteering can be understood solely as a pure public good that is provided less when others are seen to be contributing. In fact, individuals are found to be more, not less, likely to volunteer when others in their communities do so. An innovative instrumental variables strategy is used to account for reflection bias and the possible endogeneity caused by selective sorting of individuals into neighborhoods, which allows for a causal interpretation of these results. Employment regressions provide preliminary evidence that average volunteering relates, to some extent, with the decision of whether to participate in the labor force. Variations in the effect of average volunteering across age and gender are also explored. The present work is unique by virtue of its use of a large and representative dataset, along with rigorous statistical testing. I use United States Census 2000 Summary File 3 and Current Population Survey (CPS) 2004–2007 September Supplement file data and control for various individual and community-level characteristics.  相似文献   
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