全文获取类型
收费全文 | 14239篇 |
免费 | 236篇 |
专业分类
管理学 | 1867篇 |
民族学 | 147篇 |
人口学 | 2843篇 |
丛书文集 | 12篇 |
理论方法论 | 804篇 |
综合类 | 405篇 |
社会学 | 6340篇 |
统计学 | 2057篇 |
出版年
2024年 | 4篇 |
2023年 | 70篇 |
2022年 | 61篇 |
2021年 | 80篇 |
2020年 | 196篇 |
2019年 | 191篇 |
2018年 | 1903篇 |
2017年 | 1938篇 |
2016年 | 1330篇 |
2015年 | 201篇 |
2014年 | 261篇 |
2013年 | 814篇 |
2012年 | 712篇 |
2011年 | 1282篇 |
2010年 | 1158篇 |
2009年 | 883篇 |
2008年 | 922篇 |
2007年 | 1067篇 |
2006年 | 87篇 |
2005年 | 285篇 |
2004年 | 310篇 |
2003年 | 263篇 |
2002年 | 124篇 |
2001年 | 42篇 |
2000年 | 45篇 |
1999年 | 24篇 |
1998年 | 22篇 |
1997年 | 19篇 |
1996年 | 45篇 |
1995年 | 11篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 14篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 15篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 4篇 |
1971年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
Ricardo Maronna Matthias Fischer Jürgen Groß Andreas Karlsson 《Statistical Papers》2007,48(1):163-170
82.
83.
The paper and the special issue focus on the activity of statistical consulting and its varieties.
This includes academic consulting, consulting to and in industry as well as statistics in public media. 相似文献
84.
85.
The authors provide an overview of optimal scaling results for the Metropolis algorithm with Gaussian proposal distribution. They address in more depth the case of high‐dimensional target distributions formed of independent, but not identically distributed components. They attempt to give an intuitive explanation as to why the well‐known optimal acceptance rate of 0.234 is not always suitable. They show how to find the asymptotically optimal acceptance rate when needed, and they explain why it is sometimes necessary to turn to inhomogeneous proposal distributions. Their results are illustrated with a simple example. 相似文献
86.
The purpose of this paper is threefold. First, we obtain the asymptotic properties of the modified model selection criteria proposed by Hurvich et al. (1990. Improved estimators of Kullback-Leibler information for autoregressive model selection in small samples. Biometrika 77, 709–719) for autoregressive models. Second, we provide some highlights on the better performance of this modified criteria. Third, we extend the modification introduced by these authors to model selection criteria commonly used in the class of self-exciting threshold autoregressive (SETAR) time series models. We show the improvements of the modified criteria in their finite sample performance. In particular, for small and medium sample size the frequency of selecting the true model improves for the consistent criteria and the root mean square error (RMSE) of prediction improves for the efficient criteria. These results are illustrated via simulation with SETAR models in which we assume that the threshold and the parameters are unknown. 相似文献
87.
This paper studies optimum designs for linear models when the errors are heteroscedastic. Sufficient conditions are given
in order to obtainD-, A- andE-optimum designs for a complete regression model from partial optimum designs for some sub-parameters. A result about optimality
for a complete model from the optimality for the submodels is included.
Supported by Junta de Andalucía, research group FQM244. 相似文献
88.
89.
Dwight R. Lee 《Journal of Labor Research》2003,24(3):437-446
Reverse mandated benefits is a government-mandated policy that requires employees to provide their employers with benefits
that workers would not provide otherwise. Of course, only those benefits would be mandated that are worth more to employers
than they cost, as determined by political authorities. My case for such a policy argues that it is at least as sensible as
policies mandating that employers provide benefits to their employees that would not be provided otherwise. 相似文献
90.
Recently, we developed a GIS-Integrated Integral Risk Index (IRI) to assess human health risks in areas with presence of environmental pollutants. Contaminants were previously ranked by applying a self-organizing map (SOM) to their characteristics of persistence, bioaccumulation, and toxicity in order to obtain the Hazard Index (HI). In the present study, the original IRI was substantially improved by allowing the entrance of probabilistic data. A neuroprobabilistic HI was developed by combining SOM and Monte Carlo analysis. In general terms, the deterministic and probabilistic HIs followed a similar pattern: polychlorinated biphenyls (PCBs) and light polycyclic aromatic hydrocarbons (PAHs) were the pollutants showing the highest and lowest values of HI, respectively. However, the bioaccumulation value of heavy metals notably increased after considering a probability density function to explain the bioaccumulation factor. To check its applicability, a case study was investigated. The probabilistic integral risk was calculated in the chemical/petrochemical industrial area of Tarragona (Catalonia, Spain), where an environmental program has been carried out since 2002. The risk change between 2002 and 2005 was evaluated on the basis of probabilistic data of the levels of various pollutants in soils. The results indicated that the risk of the chemicals under study did not follow a homogeneous tendency. However, the current levels of pollution do not mean a relevant source of health risks for the local population. Moreover, the neuroprobabilistic HI seems to be an adequate tool to be taken into account in risk assessment processes. 相似文献