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   18397篇
  免费   576篇
  国内免费   197篇
管理学   859篇
劳动科学   2篇
民族学   192篇
人才学   4篇
人口学   238篇
丛书文集   2143篇
理论方法论   977篇
综合类   12330篇
社会学   1354篇
统计学   1071篇
  2024年   40篇
  2023年   166篇
  2022年   132篇
  2021年   185篇
  2020年   251篇
  2019年   237篇
  2018年   262篇
  2017年   331篇
  2016年   337篇
  2015年   397篇
  2014年   896篇
  2013年   1337篇
  2012年   997篇
  2011年   1192篇
  2010年   959篇
  2009年   961篇
  2008年   1056篇
  2007年   1232篇
  2006年   1343篇
  2005年   1241篇
  2004年   1127篇
  2003年   1106篇
  2002年   887篇
  2001年   759篇
  2000年   441篇
  1999年   171篇
  1998年   89篇
  1997年   69篇
  1996年   64篇
  1995年   67篇
  1994年   41篇
  1993年   33篇
  1992年   33篇
  1991年   25篇
  1990年   19篇
  1989年   17篇
  1988年   15篇
  1987年   7篇
  1986年   4篇
  1985年   100篇
  1984年   114篇
  1983年   75篇
  1982年   80篇
  1981年   63篇
  1980年   73篇
  1979年   62篇
  1978年   57篇
  1977年   8篇
  1976年   9篇
  1973年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Owing to the extreme quantiles involved, standard control charts are very sensitive to the effects of parameter estimation and non-normality. More general parametric charts have been devised to deal with the latter complication and corrections have been derived to compensate for the estimation step, both under normal and parametric models. The resulting procedures offer a satisfactory solution over a broad range of underlying distributions. However, situations do occur where even such a large model is inadequate and nothing remains but to consider non- parametric charts. In principle, these form ideal solutions, but the problem is that huge sample sizes are required for the estimation step. Otherwise the resulting stochastic error is so large that the chart is very unstable, a disadvantage that seems to outweigh the advantage of avoiding the model error from the parametric case. Here we analyse under what conditions non-parametric charts actually become feasible alternatives for their parametric counterparts. In particular, corrected versions are suggested for which a possible change point is reached at sample sizes that are markedly less huge (but still larger than the customary range). These corrections serve to control the behaviour during in-control (markedly wrong outcomes of the estimates only occur sufficiently rarely). The price for this protection will clearly be some loss of detection power during out-of-control. A change point comes in view as soon as this loss can be made sufficiently small.  相似文献   
62.
文章剖析了英美物权法上“使用权”的概念 ,并解释了财产权就像“权利集束”这个常用比喻 ,并对美国普通法上财产法中的有关相邻方之间土地纠纷的法规进行了比较分析 ,其中特别比较了普通法上的私人妨害原则和中国物权法草案第 9章所规定的相邻权的概念 ,并将普通法体系中的各种私人土地使用协议和地役权与中国物权法草案第 16章的内容进行了对比。  相似文献   
63.
Summary.  We discuss the inversion of the gas profiles (ozone, NO3, NO2, aerosols and neutral density) in the upper atmosphere from the spectral occultation measurements. The data are produced by the 'Global ozone monitoring of occultation of stars' instrument on board the Envisat satellite that was launched in March 2002. The instrument measures the attenuation of light spectra at various horizontal paths from about 100 km down to 10–20 km. The new feature is that these data allow the inversion of the gas concentration height profiles. A short introduction is given to the present operational data management procedure with examples of the first real data inversion. Several solution options for a more comprehensive statistical inversion are presented. A direct inversion leads to a non-linear model with hundreds of parameters to be estimated. The problem is solved with an adaptive single-step Markov chain Monte Carlo algorithm. Another approach is to divide the problem into several non-linear smaller dimensional problems, to run parallel adaptive Markov chain Monte Carlo chains for them and to solve the gas profiles in repetitive linear steps. The effect of grid size is discussed, and we present how the prior regularization takes the grid size into account in a way that effectively leads to a grid-independent inversion.  相似文献   
64.
论述投资控制的关键环节,提出投资控制工作的实施要点,阐明投资控制工作的必要性、可行性和重大意义.  相似文献   
65.
战后国民党政府对日派遣占领军问题是在美国的亚洲政策及对日政策的影响下提出的,是国民党政府忙于打内战使此问题未果而终。这一结局影响中国战后对日处置一些问题的实施,进而影响战后一段时期亚太地区的国际关系。  相似文献   
66.
Summary For technological applications it can be useful to identify some simple physical mechanisms, which, on the basis of the available knowledge of the production process, may suggest the most appropriate approach to statistical control of the random quantities of interest. For this purpose the notion of rupture point is introduced firstly. A rupture point is characterized bym randomly arising out of control states, assumed to be mutually exclusive and stochastically independent. Shewhart's control charts seem to represent the natural statistical tool for controlling a rupture point; however it is shown that they are fully justified only when the hazard rates attached to the causes of failure are constant. Otherwise, typically in the presence of time increasing hazard rates, Shewhart's control charts should be completed by a preventive intervention rule (preventive maintenance). In the second place, the notion of dynamic instability point is introduced, which is specifically characterized by assuming that the random quantity of interest is ruled by a stochastic differential equation with constant coefficients. By discretization, developed according to a possibly new approach, it is shown that the former model reduces to an equation error model, which is among the simplest used in adaptive control, and thus particularly easy to deal with in regard to parameter estimation and the definition of the optimum control rule.  相似文献   
67.
利用上下解,Brouwer不动点原理及Lyapunov泛函方法,讨论了一类具有反馈控制的Logistic扩散系统的周期解问题;获得了周期解存在且稳定的判别条件.  相似文献   
68.
管理行为不同层次的矛盾有其特殊性,可以选择不同的方法加以解决。制度在行为管理手段中有其适用范围,此外,机制、“人制”、自制也是行为管理的另外三种有效手段,这四种行为管理手段有着各自的特点和适用范围,有鉴别地应用好这四种行为管理手段,可以有效地解释行为管理的现象,并可指导行为管理实践。  相似文献   
69.
在19世纪末20世纪初的物理学革命中,从X射线、放射性和电子等重大发现,到相对论和量子力学的相继创建,使得物理学基本观念发生了根本变革,并对一系列物理学哲学问题展开了激烈争论。本文对物理学革命中的哲学论战进行述评,旨在深化科学哲学界对这一时期物理学哲学问题的系统研究,并以此纪念爱因斯坦逝世50周年。  相似文献   
70.
在现代社会中,权利与权利的冲突是一种较为普遍的现象.隐私权和知情权便是一对相互冲突的权利,正所谓"你要隐私,我要知情".因此如何解决两者之间的冲突,是我们不得不面对的理论和实践问题.  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