首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   9983篇
  免费   363篇
  国内免费   105篇
管理学   634篇
民族学   69篇
人口学   57篇
丛书文集   961篇
理论方法论   355篇
综合类   6474篇
社会学   367篇
统计学   1534篇
  2024年   39篇
  2023年   82篇
  2022年   105篇
  2021年   126篇
  2020年   154篇
  2019年   191篇
  2018年   212篇
  2017年   233篇
  2016年   249篇
  2015年   273篇
  2014年   555篇
  2013年   991篇
  2012年   652篇
  2011年   634篇
  2010年   591篇
  2009年   531篇
  2008年   569篇
  2007年   659篇
  2006年   659篇
  2005年   601篇
  2004年   536篇
  2003年   491篇
  2002年   395篇
  2001年   298篇
  2000年   191篇
  1999年   67篇
  1998年   37篇
  1997年   40篇
  1996年   40篇
  1995年   42篇
  1994年   39篇
  1993年   22篇
  1992年   18篇
  1991年   16篇
  1990年   21篇
  1989年   22篇
  1988年   12篇
  1987年   7篇
  1986年   3篇
  1985年   7篇
  1984年   17篇
  1983年   7篇
  1982年   3篇
  1981年   4篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   5篇
  1975年   1篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
1.
传统的国际关系理论,无论是现实主义、自由主义、建构主义还是科学行为主义理论,都是把主权国家抽象成一个统一的国际关系行为体。这一行为主体有一致的利益,也自然要有一致的对外政策目标和手段。在20世纪,尤其是在两次世界大战和冷战期间,这一概念抽象是非常准确的。但冷战结束以后,尤其是进入21世纪以后,这一概念抽象逐渐与国际关系的现实相违背。一方面,国家综合实力并不能直接转化为具体领域的竞争优势;另一方面,很多国家,包括超级大国在内,其对外政策的主要阻力可能不是所谓的竞争对手,而是其国内不同的利益集团。这导致传统的国际关系理论,从假设到概念和推理层面,都已经无法解释和预测今天的世界,而权力小博弈理论可以为认识多元复杂互动博弈时代的国际关系提供一个新的解释框架。  相似文献   
2.
In this paper, we consider the deterministic trend model where the error process is allowed to be weakly or strongly correlated and subject to non‐stationary volatility. Extant estimators of the trend coefficient are analysed. We find that under heteroskedasticity, the Cochrane–Orcutt‐type estimator (with some initial condition) could be less efficient than Ordinary Least Squares (OLS) when the process is highly persistent, whereas it is asymptotically equivalent to OLS when the process is less persistent. An efficient non‐parametrically weighted Cochrane–Orcutt‐type estimator is then proposed. The efficiency is uniform over weak or strong serial correlation and non‐stationary volatility of unknown form. The feasible estimator relies on non‐parametric estimation of the volatility function, and the asymptotic theory is provided. We use the data‐dependent smoothing bandwidth that can automatically adjust for the strength of non‐stationarity in volatilities. The implementation does not require pretesting persistence of the process or specification of non‐stationary volatility. Finite‐sample evaluation via simulations and an empirical application demonstrates the good performance of proposed estimators.  相似文献   
3.
This article considers statistical inference for the heteroscedastic partially linear varying coefficient models. We construct an efficient estimator for the parametric component by applying the weighted profile least-squares approach, and show that it is semiparametrically efficient in the sense that the inverse of the asymptotic variance of the estimator reaches the semiparametric efficiency bound. Simulation studies are conducted to illustrate the performance of the proposed method.  相似文献   
4.
When a candidate predictive marker is available, but evidence on its predictive ability is not sufficiently reliable, all‐comers trials with marker stratification are frequently conducted. We propose a framework for planning and evaluating prospective testing strategies in confirmatory, phase III marker‐stratified clinical trials based on a natural assumption on heterogeneity of treatment effects across marker‐defined subpopulations, where weak rather than strong control is permitted for multiple population tests. For phase III marker‐stratified trials, it is expected that treatment efficacy is established in a particular patient population, possibly in a marker‐defined subpopulation, and that the marker accuracy is assessed when the marker is used to restrict the indication or labelling of the treatment to a marker‐based subpopulation, ie, assessment of the clinical validity of the marker. In this paper, we develop statistical testing strategies based on criteria that are explicitly designated to the marker assessment, including those examining treatment effects in marker‐negative patients. As existing and developed statistical testing strategies can assert treatment efficacy for either the overall patient population or the marker‐positive subpopulation, we also develop criteria for evaluating the operating characteristics of the statistical testing strategies based on the probabilities of asserting treatment efficacy across marker subpopulations. Numerical evaluations to compare the statistical testing strategies based on the developed criteria are provided.  相似文献   
5.
6.
ABSTRACT

By using the probabilistic framework of production efficiency, the paper develops time-dependent conditional efficiency estimators performing a non-parametric frontier analysis. Specifically, by applying both full and quantile (robust) time-dependent conditional estimators, it models the dynamic effect of health expenditure on countries’ technological change and technological catch-up levels. The results from the application reveal that the effect of per capita health expenditure on countries’ technological change and technological catch-up is nonlinear and is subject to countries’ specific income levels.  相似文献   
7.
Influence plays a key role in reaching consensus among multiple actors involved in project-based decision-making processes. While prior literature devotes considerable attention to describing influence, little attention has been paid to influence at the individual level of the strategic project manager within the context of megaprojects. This research intended to fill this knowledge gap by identifying and describing the influence strategies that a strategic project manager applies when implementing innovation strategies on megaprojects. A qualitative case study was used to examine the complex social processes involved in a major UK capital investment programme. The findings underline a critical subset of influence strategies, notably higher-management support, inspirational appeal and bargaining. The study proposes a utilitarian structure of social power comprising selective, supportive and executory power bases.  相似文献   
8.
我国现有的国家创新系统存在效率低下和创新活力不强的问题。强化我国的创新工作应该采取适应市场 ,及时调整创新系统中各因素的角色 ;实现创新组织网络化达到资源共享 ;政府推动创新文化建设 ,营造创新氛围这三项措施 ,从而提高我国整体创新能力和国家创新系统效率。  相似文献   
9.
对于公共管理,管制是重要的管理手段。文章用经济学的观点阐述管制政策的效率原理,并在此基础上分析我国土地利用管制政策的效率,最后提出我国管制政策改进的建议和实施的条件。  相似文献   
10.
权力需要制约。邓小平不主张照搬西方那套权力制约体制,但他十分赞成对权力进行制约,猛烈抨击滥用权力造成的种种弊端。制约权力不能靠人治,道德自律和纵向权力制约固然有一定的作用,但关键要靠制度。要建立和健全一系列制约权力的获得、权力的行使、权力运行后果的制度,在党内外自下而上逐步推行选举制,建立群众不信任票达一定比例必须引咎辞职的制度,建立弹劾罢免制度以及严格的任期制,切实执行重大过错责任追究制,保证人民赋予的权力服务于人民。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号