全文获取类型
收费全文 | 6938篇 |
免费 | 427篇 |
国内免费 | 114篇 |
专业分类
管理学 | 2804篇 |
民族学 | 7篇 |
人口学 | 82篇 |
丛书文集 | 260篇 |
理论方法论 | 383篇 |
综合类 | 2782篇 |
社会学 | 478篇 |
统计学 | 683篇 |
出版年
2024年 | 12篇 |
2023年 | 129篇 |
2022年 | 96篇 |
2021年 | 105篇 |
2020年 | 246篇 |
2019年 | 237篇 |
2018年 | 230篇 |
2017年 | 262篇 |
2016年 | 259篇 |
2015年 | 263篇 |
2014年 | 386篇 |
2013年 | 636篇 |
2012年 | 436篇 |
2011年 | 419篇 |
2010年 | 347篇 |
2009年 | 327篇 |
2008年 | 343篇 |
2007年 | 351篇 |
2006年 | 363篇 |
2005年 | 360篇 |
2004年 | 289篇 |
2003年 | 250篇 |
2002年 | 200篇 |
2001年 | 185篇 |
2000年 | 102篇 |
1999年 | 91篇 |
1998年 | 55篇 |
1997年 | 48篇 |
1996年 | 41篇 |
1995年 | 40篇 |
1994年 | 55篇 |
1993年 | 39篇 |
1992年 | 31篇 |
1991年 | 29篇 |
1990年 | 36篇 |
1989年 | 22篇 |
1988年 | 33篇 |
1987年 | 23篇 |
1986年 | 19篇 |
1985年 | 13篇 |
1984年 | 18篇 |
1983年 | 17篇 |
1982年 | 17篇 |
1981年 | 16篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有7479条查询结果,搜索用时 15 毫秒
991.
Health Risk and Portfolio Choice 总被引:1,自引:0,他引:1
《商业与经济统计学杂志》2013,31(4):472-485
This article investigates the role of self-perceived risky health in explaining continued reductions in financial risk taking after retirement. If future adverse health shocks threaten to increase the marginal utility of consumption, either by absorbing wealth or by changing the utility function, then health risk should prompt individuals to lower their exposure to financial risk. I examine individual-level data from the Study of Assets and Health Dynamics Among the Oldest Old (AHEAD), which reveal that risky health prompts safer investment. Elderly singles respond the most to health risk, consistent with a negative cross partial deriving from health shocks that impede home production. Spouses and planned bequests provide some degree of hedging. Risky health may explain 20%% of the age-related decline in financial risk taking after retirement. 相似文献
992.
993.
Stephen J. Brown 《统计学通讯:模拟与计算》2013,42(4):321-334
For the portfolio problem with unknown parameter values, we compare the conventional certainty equivalence portfolio choice with the optimal Bayes portfolio. In the important single risky asset case a diffuse Bayes rule leads to portfolios that differ significantly from those suggested by a certainty equivalence rule which we show are inadmissible relative to a quadratic utility function for the range of parameters we consider. These results are invariant to arbitrary changes in the utility function parameters. We illustrate the results using a simple mutual fund example. 相似文献
994.
We consider the problem of estimating the coefficient vector β of a linear regression model with quadratic loss function. Some biased estimators which utilize the prior information about β are considered. Also studied is the problem of estimating the parameters of an over-identified structural equation from undersized samples. 相似文献
995.
Ken-Ichi Koike 《统计学通讯:理论与方法》2013,42(12):2185-2195
In this article, some results are derived on stochastic comparisons of the residual and past lifetimes of an (n ? k + 1)-out-of-n system with dependent components. These findings generalize some recent results obtained on systems with independent components and provide some interesting results for a system with dependent components following an Archimedean copula. An illustrative example is provided. 相似文献
996.
Khalaf S. Sultan A. S. Al-Moisheer 《Journal of Statistical Computation and Simulation》2013,83(10):1900-1914
The main goal of this paper is to develop the approximate Bayes estimation of the five-dimensional vector of the parameters and reliability function of a mixture of two inverse Weibull distributions (MTIWD) under Type-2 censoring. Usually, the posterior distribution is complicated under the scheme of Type-2 censoring and the integrals that are involved cannot be obtained in a simple explicit form. In this study, we use Lindley's [Approximate Bayesian method, Trabajos Estadist. 31 (1980), pp. 223–237] approximate form of Bayes estimation in the case of an MTIWD under Type-2 censoring. Later, we calculate the estimated risks (ERs) of the Bayes estimates and compare them with the corresponding ERs of the maximum-likelihood estimates through Monte Carlo simulation. Finally, we analyse a real data set using the findings. 相似文献
997.
基于多维度感知风险,调查中国公众的献血意愿现状,探讨其影响因素,为无偿献血者招募与保留工作提供科学依据。本文从公众对献血行为、心理、情境、制度、偏见、服务、宣传七个维度的感知风险入手,在问卷调查与因素分析的基础上,基于实证分析,解释各种因素之间的相互关系,揭示不同特征中国公众献血意愿的差异,进而有针对性地制定无偿献血招募及保留措施,促进我国无偿献血事业可持续发展。 相似文献
998.
地缘政治风险日渐高企,冲击和影响着全球贸易与投资,构成左右全球经济复苏、政治格局演变和地缘关系重构的推力,也成为国内外国际政治、国际关系、国际经济等领域关注研究的前沿问题。通过梳理分析近些年地缘政治风险的经济效应,即地缘政治风险的技术创新效应、开放经济效应、经济增长效应等,试图为研究和制定相关政策提供研究脉络、研究内容、主要观点和前景展望等方面的一些有益启发。 相似文献
999.
The partial attributable risk (PAR) has been introduced as a tool for partitioning the responsibility for causing an adverse event between various risk factors. It has arisen from epidemiology, but it is also a valid general risk allocation concept, which can, for example, be applied to data from customer satisfaction surveys. So far, a variance formula for the PAR has been missing so that the confidence intervals were not directly available. This paper provides the asymptotic normal distribution for the PAR determined from a cross-sectional study. 相似文献
1000.
In this paper, methods are proposed in finding the robust design in both Taguchi and Standard setups when a signal factor is present. The robust design is a set of level combinations of control factors so that the effect of controllable noise factors on response is minimum. Both univariate and multivariate methods are used in finding the influential noise factors for the determination of robust designs. 相似文献