全文获取类型
收费全文 | 5510篇 |
免费 | 123篇 |
国内免费 | 35篇 |
专业分类
管理学 | 295篇 |
民族学 | 18篇 |
人才学 | 1篇 |
人口学 | 80篇 |
丛书文集 | 124篇 |
理论方法论 | 50篇 |
综合类 | 1335篇 |
社会学 | 84篇 |
统计学 | 3681篇 |
出版年
2024年 | 11篇 |
2023年 | 31篇 |
2022年 | 61篇 |
2021年 | 73篇 |
2020年 | 89篇 |
2019年 | 174篇 |
2018年 | 228篇 |
2017年 | 322篇 |
2016年 | 196篇 |
2015年 | 163篇 |
2014年 | 226篇 |
2013年 | 1255篇 |
2012年 | 425篇 |
2011年 | 234篇 |
2010年 | 199篇 |
2009年 | 206篇 |
2008年 | 230篇 |
2007年 | 192篇 |
2006年 | 181篇 |
2005年 | 180篇 |
2004年 | 160篇 |
2003年 | 141篇 |
2002年 | 123篇 |
2001年 | 88篇 |
2000年 | 92篇 |
1999年 | 70篇 |
1998年 | 63篇 |
1997年 | 44篇 |
1996年 | 22篇 |
1995年 | 31篇 |
1994年 | 20篇 |
1993年 | 23篇 |
1992年 | 23篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1975年 | 1篇 |
排序方式: 共有5668条查询结果,搜索用时 0 毫秒
11.
基于主成分分析的我国西部地区间产业结构转换能力评价 总被引:3,自引:0,他引:3
产业结构的演进和转换是经济发展的本质特征,也是促进经济持续稳定协调发展的关键。西部地区产业结构转换能力的地区差异十分明显,本文阐述了影响地区产业结构转换的一般因素,并通过主成分分析方法对影响西部地区产业结构转换的主要因素进行了分析,并对西部各地区产业结构转换能力、转换速度以及转换方向进行了分析评价。 相似文献
12.
Donald B. Rubin 《Scandinavian Journal of Statistics》2004,31(2):161-170
Abstract. The use of the concept of ‘direct’ versus ‘indirect’ causal effects is common, not only in statistics but also in many areas of social and economic sciences. The related terms of ‘biomarkers’ and ‘surrogates’ are common in pharmacological and biomedical sciences. Sometimes this concept is represented by graphical displays of various kinds. The view here is that there is a great deal of imprecise discussion surrounding this topic and, moreover, that the most straightforward way to clarify the situation is by using potential outcomes to define causal effects. In particular, I suggest that the use of principal stratification is key to understanding the meaning of direct and indirect causal effects. A current study of anthrax vaccine will be used to illustrate ideas. 相似文献
13.
探索、检验因果关系是教育科学研究的重要目标之一,相关分析、回归分析、路径分析等常用统计方法存在许多不足。结构方程模型是针对这些不足提出来的,从统计思路上,它具有优点,但还不够完善,应引起我国教育学界的注意。 相似文献
14.
We used two statistical methods to identify prognostic factors: a log-linear model (logistic and COX regression, based on the notions of linearity and multiplicative relative risk), and the CORICO method (ICOnography of CORrelations) based on the geometric significance of the correlation coefficient. We applied the methods to two different situations (a "case-control study' and a "historical cohort'). We show that the geometric exploratory tool is particularly suited to the analysis of small samples with a large number of variables. It could save time when setting up new study protocols. In this instance, the geometric approach highlighted, without preconceived ideas, the potential role of multihormonality in the course of pituitary adenoma and the unexpected influence of the date of tumour excision on the risk attached to haemorrhage. 相似文献
15.
俞颖 《安徽大学学报(哲学社会科学版)》2004,28(5):143-148
本文用信息经济学的理论和计量经济学的实证分析方法研究了我国核准制下的新股定价问题 ,指出市场主体决策时的信息差异是造成新股发行价和上市价相背离的主要原因 ,并构建多元回归模型对这一假设进行了检验。 相似文献
16.
We analyse whether the psychological pricing in the private sector has a public sector counterpart in tax policy. Analysing the main theoretical arguments for the existence of price points, and applying them to the public sector, suggests that psychological taxing reveals itself by the use of non-0 ending tax rates. The tax rate endings of the local income taxes, which are set by 308 Flemish municipalities in the fiscal year 1998, suggests the presence of psychological taxing. Non-0 endings occur more frequently in municipalities where demand for public policy is more elastic (and where, therefore, the benefits to the politicians from setting a tax just below a tax point is higher). The pre-tax income inequality and the level of the tax rate positively affect psychological taxing. The latter effect is reinforced in those municipalities where the existing tax rate is above the average tax rate in neighbouring municipalities and below their neighbours’ minimum, although this effect has a limited effect and is offset the further below the minimum the tax is set. 相似文献
17.
Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables. 相似文献
18.
Wing-Kam Fung Zhong-Yi Zhu Bo-Cheng Wei Xuming He 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2002,64(3):565-579
Summary. Semiparametric mixed models are useful in biometric and econometric applications, especially for longitudinal data. Maximum penalized likelihood estimators (MPLEs) have been shown to work well by Zhang and co-workers for both linear coefficients and nonparametric functions. This paper considers the role of influence diagnostics in the MPLE by extending the case deletion and subject deletion analysis of linear models to accommodate the inclusion of a nonparametric component. We focus on influence measures for the fixed effects and provide formulae that are analogous to those for simpler models and readily computable with the MPLE algorithm. We also establish an equivalence between the case or subject deletion model and a mean shift outlier model from which we derive tests for outliers. The influence diagnostics proposed are illustrated through a longitudinal hormone study on progesterone and a simulated example. 相似文献
19.
浅论教师在多媒体教学中的主体地位 总被引:2,自引:0,他引:2
李永胜 《安徽农业大学学报(社会科学版)》2002,11(1):78-79
运用现代多媒体教学手段,是实现教育方法现代化的必由之路,但教师在现代多媒体教学中的主体地位是不可替代的,多媒体教学在高等教育教学中发挥的作用如何,主要取决于教师的主体地位。 相似文献
20.
Gaussian Markov random field (GMRF) models are commonly used to model spatial correlation in disease mapping applications. For Bayesian inference by MCMC, so far mainly single-site updating algorithms have been considered. However, convergence and mixing properties of such algorithms can be extremely poor due to strong dependencies of parameters in the posterior distribution. In this paper, we propose various block sampling algorithms in order to improve the MCMC performance. The methodology is rather general, allows for non-standard full conditionals, and can be applied in a modular fashion in a large number of different scenarios. For illustration we consider three different applications: two formulations for spatial modelling of a single disease (with and without additional unstructured parameters respectively), and one formulation for the joint analysis of two diseases. The results indicate that the largest benefits are obtained if parameters and the corresponding hyperparameter are updated jointly in one large block. Implementation of such block algorithms is relatively easy using methods for fast sampling of Gaussian Markov random fields ( Rue, 2001 ). By comparison, Monte Carlo estimates based on single-site updating can be rather misleading, even for very long runs. Our results may have wider relevance for efficient MCMC simulation in hierarchical models with Markov random field components. 相似文献