全文获取类型
收费全文 | 8847篇 |
免费 | 280篇 |
国内免费 | 94篇 |
专业分类
管理学 | 239篇 |
劳动科学 | 3篇 |
民族学 | 276篇 |
人口学 | 71篇 |
丛书文集 | 1158篇 |
理论方法论 | 408篇 |
综合类 | 6394篇 |
社会学 | 282篇 |
统计学 | 390篇 |
出版年
2024年 | 18篇 |
2023年 | 63篇 |
2022年 | 89篇 |
2021年 | 110篇 |
2020年 | 153篇 |
2019年 | 141篇 |
2018年 | 132篇 |
2017年 | 166篇 |
2016年 | 192篇 |
2015年 | 218篇 |
2014年 | 556篇 |
2013年 | 493篇 |
2012年 | 604篇 |
2011年 | 716篇 |
2010年 | 633篇 |
2009年 | 545篇 |
2008年 | 576篇 |
2007年 | 769篇 |
2006年 | 675篇 |
2005年 | 565篇 |
2004年 | 490篇 |
2003年 | 454篇 |
2002年 | 313篇 |
2001年 | 220篇 |
2000年 | 149篇 |
1999年 | 58篇 |
1998年 | 29篇 |
1997年 | 19篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有9221条查询结果,搜索用时 31 毫秒
21.
基于主体功能区划自然保护区生态补偿机制之构建与完善 总被引:3,自引:0,他引:3
王权典 《华南农业大学学报(社会科学版)》2010,9(1):122-129
根据国家主体功能区划,自然保护区被界定为禁止开发区域,必然要对其科学有效地实施生态补偿;自然保护区生态补偿机制应当结合当前主体功能区划的政策导向,进行重新定位与构建。依据公共物品与外部性等理论,为缓解现实矛盾,需积极探索构建多元化融资渠道的保护区生态补偿机制,主要涉及政府与市场两种基本途径或机制范畴,合理安排相应的政策引导与制度创新。制度构建的关键在于加快自然保护区生态补偿的立法调整,无论是政府财政转移支付还是市场经济手段的生态补偿政策,都需要立法确定其方针原则、实施模式及机制。 相似文献
22.
23.
在我国企业集团的发展过程中,我国政府直接参与了企业集团的兼并重组进程,为了应对国际大集团大公司的挑战,在当前经济全球一体化的大背景下,需要进一步认识在企业集团兼并重组中的政府行为的作用和政府行为方式,政府行为干预的局限性,以及政府在企业集团兼并重组过程中该扮演什么样的角色.以便使政府能更有效地推动企业集团的兼并重组.早日实现做强做大的目标,更好地实施"走出去"发展战略.总体来讲,目前政府还不可能从企业集团的兼并重组过程中超脱出来,还需要政府进一步优化企业集团兼并重组的宏观环境,可以说,由政府直接介入企业集团的兼并重组转向利用法制手段强化对企业集团兼并重组行为的监管应是现在和将来的发展方向. 相似文献
24.
L. Yang & R. Tschernig 《Journal of the Royal Statistical Society. Series B, Statistical methodology》1999,61(4):793-815
The existence and properties of optimal bandwidths for multivariate local linear regression are established, using either a scalar bandwidth for all regressors or a diagonal bandwidth vector that has a different bandwidth for each regressor. Both involve functionals of the derivatives of the unknown multivariate regression function. Estimating these functionals is difficult primarily because they contain multivariate derivatives. In this paper, an estimator of the multivariate second derivative is obtained via local cubic regression with most cross-terms left out. This estimator has the optimal rate of convergence but is simpler and uses much less computing time than the full local estimator. Using this as a pilot estimator, we obtain plug-in formulae for the optimal bandwidth, both scalar and diagonal, for multivariate local linear regression. As a simpler alternative, we also provide rule-of-thumb bandwidth selectors. All these bandwidths have satisfactory performance in our simulation study. 相似文献
25.
杨廉英 《电子科技大学学报(社会科学版)》1988,(4)
本文提出了一种宽带分布式网络设计,该网络能在CATV电缆上同时进行数据、实时数字话音及模拟电视通信。本系统能支持大量用户间的通信。由于采用了宽带技术和总线网令牌与CSMA/CD的混合协议,从而解决了局域网所面临的距离和时延问题。本文最后对所提出网络的话音性能作了评估,所得结果与相关试验报导数据相符。 相似文献
26.
27.
Abstract. This article presents a framework for comparing bivariate distributions according to their degree of regression dependence. We introduce the general concept of a regression dependence order (RDO). In addition, we define a new non‐parametric measure of regression dependence and study its properties. Besides being monotone in the new RDOs, the measure takes on its extreme values precisely at independence and almost sure functional dependence, respectively. A consistent non‐parametric estimator of the new measure is constructed and its asymptotic properties are investigated. Finally, the finite sample properties of the estimate are studied by means of a small simulation study. 相似文献
28.
The outer product of gradients (OPG) estimation procedure based on least squares (LS) approach has been presented by Xia et al. [An adaptive estimation of dimension reduction space. J Roy Statist Soc Ser B. 2002;64:363–410] to estimate the single-index parameter in partially linear single-index models (PLSIM). However, its asymptotic property has not been established yet and the efficiency of LS-based method can be significantly affected by outliers and heavy-tailed distributions. In this paper, we firstly derive the asymptotic property of OPG estimator developed by Xia et al. [An adaptive estimation of dimension reduction space. J Roy Statist Soc Ser B. 2002;64:363–410] in theory, and a novel robust estimation procedure combining the ideas of OPG and local rank (LR) inference is further developed for PLSIM along with its theoretical property. Then, we theoretically derive the asymptotic relative efficiency (ARE) of the proposed LR-based procedure with respect to LS-based method, which is shown to possess an expression that is closely related to that of the signed-rank Wilcoxon test in comparison with the t-test. Moreover, we demonstrate that the new proposed estimator has a great efficiency gain across a wide spectrum of non-normal error distributions and almost not lose any efficiency for the normal error. Even in the worst case scenarios, the ARE owns a lower bound equalling to 0.864 for estimating the single-index parameter and a lower bound being 0.8896 for estimating the nonparametric function respectively, versus the LS-based estimators. Finally, some Monte Carlo simulations and a real data analysis are conducted to illustrate the finite sample performance of the estimators. 相似文献
29.
Luis Hernando Vanegas Gauss M. Cordeiro 《Journal of Statistical Computation and Simulation》2013,83(12):2315-2338
We propose some statistical tools for diagnosing the class of generalized Weibull linear regression models [A.A. Prudente and G.M. Cordeiro, Generalized Weibull linear models, Comm. Statist. Theory Methods 39 (2010), pp. 3739–3755]. This class of models is an alternative means of analysing positive, continuous and skewed data and, due to its statistical properties, is very competitive with gamma regression models. First, we show that the Weibull model induces ma-ximum likelihood estimators asymptotically more efficient than the gamma model. Standardized residuals are defined, and their statistical properties are examined empirically. Some measures are derived based on the case-deletion model, including the generalized Cook's distance and measures for identifying influential observations on partial F-tests. The results of a simulation study conducted to assess behaviour of the global influence approach are also presented. Further, we perform a local influence analysis under the case-weights, response and explanatory variables perturbation schemes. The Weibull, gamma and other Weibull-type regression models are fitted into three data sets to illustrate the proposed diagnostic tools. Statistical analyses indicate that the Weibull model fitted into these data yields better fits than other common alternative models. 相似文献
30.
A multiparameter extension is made to modified two stage shrinkage estimator proposed by Handa andKambo (1990), For aparticular class of shrinkage estimator, the local optimality of the extended modified estimator is shown over the two stage shrinkage estimator defined by Bhattacharya and Prakasa Rao(1990) in terms of quadratic loss. 相似文献