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   214篇
  免费   7篇
管理学   39篇
民族学   4篇
人口学   32篇
丛书文集   1篇
理论方法论   25篇
综合类   2篇
社会学   83篇
统计学   35篇
  2023年   3篇
  2022年   2篇
  2021年   1篇
  2020年   6篇
  2019年   15篇
  2018年   11篇
  2017年   11篇
  2016年   13篇
  2015年   4篇
  2014年   5篇
  2013年   34篇
  2012年   10篇
  2011年   13篇
  2010年   8篇
  2009年   6篇
  2008年   7篇
  2007年   10篇
  2006年   12篇
  2005年   2篇
  2004年   8篇
  2003年   5篇
  2002年   5篇
  2001年   4篇
  2000年   1篇
  1999年   4篇
  1998年   2篇
  1997年   1篇
  1995年   1篇
  1994年   2篇
  1992年   1篇
  1991年   3篇
  1989年   1篇
  1987年   1篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1977年   1篇
  1976年   1篇
  1973年   1篇
  1971年   1篇
排序方式: 共有221条查询结果,搜索用时 156 毫秒
1.
We critically review conceptual and empirical issues surrounding the derivation of the international poverty line, expressed in PPP-adjusted dollars and linked to various rounds of the International Comparison Program (ICP). We find that there are some limitations in the current estimation of these lines, but show that statistically superior methods lead to lines that are relatively robust and confirm the $1.25 using 2005 PPPs and suggest $1.67–1.71 using 2011 PPPs (or close to the $1.90 proposed by the World Bank if we follow the World Bank’s approach of adjusting inflation rates in some countries); they also roughly confirm the current shape of the proposed ‘weakly relative’ poverty line. Using the new absolute line based on 2011 PPPs would lead to substantially lower poverty in our estimation. The extent of the decline depends on whether and how one treats China, India, and Indonesia differently from other countries in the 2005 and 2011 PPPs. More seriously, we note that the dependence on successive ICP rounds creates conceptual and empirical problems that have become worse over time so that we suggest that it would be best to consider alternatives to the current reliance on ICP rounds and the resulting PPPs. As a short-term solution we propose to fix the international poverty line in national currencies using either the 2005 or 2011 level; in the medium term, we argue for global poverty measurement based on internationally coordinated national poverty measurement.  相似文献   
2.
This article develops two block bootstrap-based panel predictability test procedures that are valid under very general conditions. Some of the allowable features include cross-sectional dependence, heterogeneous predictive slopes, persistent predictors, and complex error dynamics, including cross-unit endogeneity. While the first test procedure tests if there is any predictability at all, the second procedure determines the units for which predictability holds in case of a rejection by the first. A weak unit root framework is adopted to allow persistent predictors, and a novel theory is developed to establish asymptotic validity of the proposed bootstrap. Simulations are used to evaluate the performance of our tests in small samples, and their implementation is illustrated through an empirical application to stock returns.  相似文献   
3.
Retail business development is a broad goal for both private business interests as well as local policymakers, yet the goal of retail opportunities for local residents themselves is often seen as secondary. This paper considers the argument that retail opportunities and sense of community are in fact linked in important ways, links that reinforce the social fabric of a community and/or neighborhood. The paper first briefly reviews the inherent linkages between retail shopping and local development patterns, and then considers the sense of community in the context of Garfield County in western Colorado. Based on the key questions derived from this background, we formally test the inter-relationship between local retail spending and sense of community from detailed survey data, then more broadly consider the factors that critically shape a locality's “sense of community.” These findings shape several important policy implications.  相似文献   
4.
Background: Testosterone (TT) and dehydroepiandrosterone sulphate (DHEAS) are neurosteroids and their deficiencies constitute the hormone risk factors promoting the development of depression in elderly otherwise healthy men. We investigated the link between hypogonadism and depression in accordance with age and concomitant diseases in men with systolic HF using the novel scale previously dedicated for elderly population.

Methods: We analysed the prevalence of depression and severity of depressive symptoms in population of 226 men with systolic HF (40–80 years) compared to 379 healthy peers. The severity of depression was assessed using the Polish long version of Geriatric Depression Scale (GDS).

Results: In men aged 40–59 years the severity of depressive symptoms was greater in NYHA classes III–IV compared to NYHA classes I–II and reference group. In men aged 60–80 years depressive symptoms were more severe in NYHA class III-IV compared to controls (all p?≤?0.001). In multivariate logistic regression model in men aged 40–59 years advanced NYHA class was associated with higher prevalence of mild depression (OR?=?2.14, 95%CI: 1.07–4.29) and chronic obstructive pulmonary disease (COPD) with higher prevalence of severe depression (OR?=?69.1, 95%CI: 2.11–2264.3). In men aged 60–80 years advanced NYHA class and TT deficiency were related to higher prevalence of mild depression (respectively: OR?=?2.9, 95%CI: 1.3–6.4; OR?=?3.6, 95%CI: 1.2–10.63).

Conclusion: TT deficiency, COPD and advanced NYHA class were associated with higher prevalence of depression in men with systolic HF.  相似文献   
5.
We propose novel parametric concentric multi‐unimodal small‐subsphere families of densities for p ? 1 ≥ 2‐dimensional spherical data. Their parameters describe a common axis for K small hypersubspheres, an array of K directional modes, one mode for each subsphere, and K pairs of concentrations parameters, each pair governing horizontal (within the subsphere) and vertical (orthogonal to the subsphere) concentrations. We introduce two kinds of distributions. In its one‐subsphere version, the first kind coincides with a special case of the Fisher–Bingham distribution, and the second kind is a novel adaption that models independent horizontal and vertical variations. In its multisubsphere version, the second kind allows for a correlation of horizontal variation over different subspheres. In medical imaging, the situation of p ? 1 = 2 occurs precisely in modeling the variation of a skeletally represented organ shape due to rotation, twisting, and bending. For both kinds, we provide new computationally feasible algorithms for simulation and estimation and propose several tests. To the best knowledge of the authors, our proposed models are the first to treat the variation of directional data along several concentric small hypersubspheres, concentrated near modes on each subsphere, let alone horizontal dependence. Using several simulations, we show that our methods are more powerful than a recent nonparametric method and ad hoc methods. Using data from medical imaging, we demonstrate the advantage of our method and infer on the dominating axis of rotation of the human knee joint at different walking phases.  相似文献   
6.
This study examined whether prenatal reflective functioning (RF) was related to mothers’ interactive style across contexts with their 6‐month‐old infants (M age = 6.02 months, SD = 0.41, 54% boys), and to what extent quality of prenatal RF could account for the influence of accumulated risk on maternal interactive behavior. Accumulated risk was defined as the sum‐score of a selection of risk factors that have been associated with suboptimal infant development. Mother–infant dyads (N = 133) were observed during free play, two teaching tasks, and the Still‐Face Paradigm (SFP). Better prenatal RF was associated with more positive maternal behavior in all settings and less negative behavior during teaching and SFP reengagement. Accumulated risk and prenatal RF predicted shared variance in maternal interactive behavior (with unique predictive effects observed only for RF on sensitivity during teaching and SFP play, and for accumulated risk on sensitivity and positive engagement during SFP play, and internalizing‐helplessness during SFP reengagement). Accumulated risk had an indirect effect on maternal sensitivity during teaching and SFP play through prenatal RF. These findings suggest not only that RF may be targeted prenatally to improve mother–infant interactions, but also that enhancing RF skills may ameliorate some of the negative consequences from more stable perinatal risk factors that influence parent–child interactions.  相似文献   
7.
This study seeks to extend the body of knowledge of pro-social behavior in comparative market settings by reporting on a high-stakes ultimatum game and revelation game experiments in two transition economies: Kazakhstan and Uzbekistan. While controlling for cultural differences and framing effects, we find statistically significant differences in fairness and honesty behavior between the two countries. Specifically, subjects in Uzbekistan (in an earlier stage of transition to a market economy) are fairer and more honest than their later-stage Kazakh counterparts. Our experimental findings have implications for the literature on pro-social behavior and market economies, and more generally, on the transmission process between formal and informal institutions.  相似文献   
8.
Beyond Agency   总被引:1,自引:0,他引:1  
The reason why agency/structure and micro/macro debates remain unresolved is the bad essentialist habit of treating such pairs as opposite natural kinds. Once variation is allowed, agency and structure, or micro and macro, are temporary poles bracketing a continuum, with social entities moving along this continuum over time. Explaining these transformations from agency into structure, or micro into macro, and vice versa is the challenge for explanatory theory. This challenge is met by switching to a constructivist level of second-order observing. Then, agency and structure become variable devices or frames different observers might use to perform different sorts of cultural work.  相似文献   
9.
We propose two preprocessing algorithms suitable for climate time series. The first algorithm detects outliers based on an autoregressive cost update mechanism. The second one is based on the wavelet transform, a method from pattern recognition. In order to benchmark the algorithms'' performance we compare them to existing methods based on a synthetic data set. Eventually, for exemplary purposes, the proposed methods are applied to a data set of high-frequent temperature measurements from Novi Sad, Serbia. The results show that both methods together form a powerful tool for signal preprocessing: In case of solitary outliers the autoregressive cost update mechanism prevails, whereas the wavelet-based mechanism is the method of choice in the presence of multiple consecutive outliers.  相似文献   
10.
A number of recent papers have focused on the problem of testing for a unit root in the case where the driving shocks may be unconditionally heteroskedastic. These papers have, however, taken the lag length in the unit root test regression to be a deterministic function of the sample size, rather than data-determined, the latter being standard empirical practice. We investigate the finite sample impact of unconditional heteroskedasticity on conventional data-dependent lag selection methods in augmented Dickey–Fuller type regressions and propose new lag selection criteria which allow for unconditional heteroskedasticity. Standard lag selection methods are shown to have a tendency to over-fit the lag order under heteroskedasticity, resulting in significant power losses in the (wild bootstrap implementation of the) augmented Dickey–Fuller tests under the alternative. The proposed new lag selection criteria are shown to avoid this problem yet deliver unit root tests with almost identical finite sample properties as the corresponding tests based on conventional lag selection when the shocks are homoskedastic.  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