全文获取类型
收费全文 | 2733篇 |
免费 | 106篇 |
国内免费 | 20篇 |
专业分类
管理学 | 241篇 |
民族学 | 11篇 |
人口学 | 56篇 |
丛书文集 | 264篇 |
理论方法论 | 133篇 |
综合类 | 1212篇 |
社会学 | 214篇 |
统计学 | 728篇 |
出版年
2024年 | 5篇 |
2023年 | 21篇 |
2022年 | 22篇 |
2021年 | 26篇 |
2020年 | 63篇 |
2019年 | 71篇 |
2018年 | 82篇 |
2017年 | 90篇 |
2016年 | 74篇 |
2015年 | 81篇 |
2014年 | 137篇 |
2013年 | 322篇 |
2012年 | 150篇 |
2011年 | 176篇 |
2010年 | 140篇 |
2009年 | 137篇 |
2008年 | 164篇 |
2007年 | 144篇 |
2006年 | 161篇 |
2005年 | 137篇 |
2004年 | 143篇 |
2003年 | 114篇 |
2002年 | 116篇 |
2001年 | 79篇 |
2000年 | 61篇 |
1999年 | 28篇 |
1998年 | 23篇 |
1997年 | 16篇 |
1996年 | 11篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 5篇 |
排序方式: 共有2859条查询结果,搜索用时 15 毫秒
181.
In this article, we develop regression models with cross‐classified responses. Conditional independence structures can be explored/exploited through the selective inclusion/exclusion of terms in a certain functional ANOVA decomposition, and the estimation is done nonparametrically via the penalized likelihood method. A cohort of computational and data analytical tools are presented, which include cross‐validation for smoothing parameter selection, Kullback–Leibler projection for model selection, and Bayesian confidence intervals for odds ratios. Random effects are introduced to model possible correlations such as those found in longitudinal and clustered data. Empirical performances of the methods are explored in simulation studies of limited scales, and a real data example is presented using some eyetracking data from linguistic studies. The techniques are implemented in a suite of R functions, whose usage is briefly described in the appendix. The Canadian Journal of Statistics 39: 591–609; 2011. © 2011 Statistical Society of Canada 相似文献
182.
TYLER J. VANDERWEELE 《Scandinavian Journal of Statistics》2011,38(3):551-563
Abstract. Results are given which provide bounds for controlled direct effects when nounmeasured confounding assumptions required for the identification of these effects do not hold. Previous results concerning bounds for controlled direct effects rely on monotonicity relationships between the treatment, mediator and the outcome themselves; the results presented in this article instead assume that monotonicity relationships hold between the unmeasured confounding variable or variables and the treatment, mediator and outcome. Whereas prior results give bounds that contain the null hypothesis of no direct effect, the results presented here will in many instances yield bounds that do not contain the null hypothesis of no direct effect. For contexts in which a set of variables intercepts all paths between a treatment and an outcome, it is possible to provide a definition for a controlled mediated effect. We discuss the identification of these controlled mediated effects; the bounds for controlled direct effects are applicable also to controlled mediated effects. An example is given to illustrate how the results in the article can be used to draw inferences about direct and mediated effects in the presence of unmeasured confounding variables. 相似文献
183.
Poduri S.R.S. Rao 《统计学通讯:理论与方法》2013,42(15):1659-1669
The MINQUE and its modifications are considered for estimating the variances of the balanced one-way random effects model. The effects of the a priori values on the estimators of the variances are examined in detail. The Mean Square Errors of the estimators are compared for variations in the prior values of the unknown variances. 相似文献
184.
阐述了企业经理人员股票期权制(ESO)的含义、作用和形式.分析了在我国现阶段推行该计划的主要问题,并据此提出了适合我国企业实情的对策. 相似文献
185.
Dose-Response Assessment of Airborne Methyl Isothiocyanate (MITC) Following a Metam Sodium Spill 总被引:3,自引:0,他引:3
George V. Alexeeff Dennis J. Shusterman Robert A. Howd Richard J. Jackson 《Risk analysis》1994,14(2):191-198
A tank car derailment in northern California in 1991 spilled metam sodium into the Sacramento River, and released its breakdown product, methyl isothiocyanate (MITC), into the air. This paper describes the risk evaluation process used. Over 240 individuals reported symptoms such as eye and throat irritation, dizziness, and shortness of breath. Reference exposure levels (RELs) for 1 hr were developed for MITC and compared to exposure concentrations. Ocular irritation in cats was the most sensitive endpoint reported. The no observed adverse effect level (NOAEL), divided by an uncertainty factor (UF) of 100, produced an REL of 0.5 ppb of MITC in air to prevent discomfort. An REL to prevent disability was estimated to be 40 ppb. An REL to prevent life-threatening injury was estimated to be 150 ppb. Measured MITC levels ranged from 0.2-37 ppb and estimated peak levels ranged from 140-1600 ppb. The usefulness of RELs for emergency planning is discussed. 相似文献
186.
张卫萍 《中南大学学报(社会科学版)》2002,(2)
奈达把翻译的过程分为分析 -转化 -重组三个步骤。本文通过区分及分析翻译过程中分析的对象与分析的参照物 ,论证了在绝大部分情况下 ,整个语篇不是也不必是译者分析的对象 ,它只起语境的作用 ,从而证明了翻译中“句本位”的合理性 相似文献
187.
兼并效应与产品覆盖策略 总被引:13,自引:1,他引:13
在行业寡头垄断竞争中, 引入产品覆盖策略竞争的变量, 把企业兼并时的竞争假定为两
个阶段两种变量: 先是产品覆盖策略竞争, 后是产品产量竞争, 并设计了一个描述这种兼并竞
争的模型. 在此基础上, 分析了参与和未参与兼并的企业的产品覆盖策略变化对各企业利润和
价格的影响, 在一定程度上解释了兼并悖论. 我们赞成适度的兼并控制政策, 但在经济萧条时
期可适当放宽. 相似文献
188.
This paper examines survey data relating class mobility to satisfaction and dissatisfaction with seven different domains of everyday life among nationally representative samples of men and women living in ten industrialized nations. The evidence is set against competing pessimistic and optimistic accounts of the mobility experience found in earlier literature. Results show that individuals who move from working-class origins to middle-class destinations are no more likely to be systematically satisfied or dissatisfied with life than are the socially immobile or even those downwardly mobile from advantaged backgrounds into the working class. Indeed, in all nations, the overall association between class experience and satisfaction with life is both weak and uneven across the different life-domains. The study also serves to illustrate an important principle of research methodology more generally. 相似文献
189.
Residential building codes intended to promote health and safety may produce unintended countervailing risks by adding to the cost of construction. Higher construction costs increase the price of new homes and may increase health and safety risks through income and stock effects. The income effect arises because households that purchase a new home have less income remaining for spending on other goods that contribute to health and safety. The stock effect arises because suppression of new-home construction leads to slower replacement of less safe housing units. These countervailing risks are not presently considered in code debates. We demonstrate the feasibility of estimating the approximate magnitude of countervailing risks by combining the income effect with three relatively well understood and significant home-health risks. We estimate that a code change that increases the nationwide cost of constructing and maintaining homes by $150 (0.1% of the average cost to build a single-family home) would induce offsetting risks yielding between 2 and 60 premature fatalities or, including morbidity effects, between 20 and 800 lost quality-adjusted life years (both discounted at 3%) each year the code provision remains in effect. To provide a net health benefit, the code change would need to reduce risk by at least this amount. Future research should refine these estimates, incorporate quantitative uncertainty analysis, and apply a full risk-tradeoff approach to real-world case studies of proposed code changes. 相似文献
190.
Some practical issues in the evaluation of heterogeneous labour market programmes by matching methods 总被引:1,自引:0,他引:1
Michael Lechner 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2002,165(1):59-82
Summary. Recently several studies have analysed active labour market policies by using a recently proposed matching estimator for multiple programmes. Since there is only very limited practical experience with this estimator, this paper checks its sensitivity with respect to issues that are of practical importance in this kind of evaluation study. The estimator turns out to be fairly robust to several features that concern its implementation. Furthermore, the paper demonstrates that the matching approach per se is no panacea for solving all the problems of evaluation studies, but that its success depends critically on the information that is available in the data. Finally, a comparison with a bootstrap distribution provides some justification for using a simplified approximation of the distribution of the estimator that ignores its sequential nature. 相似文献