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   16591篇
  免费   603篇
  国内免费   201篇
管理学   625篇
劳动科学   2篇
民族学   239篇
人才学   2篇
人口学   224篇
丛书文集   1675篇
理论方法论   804篇
综合类   9978篇
社会学   1374篇
统计学   2472篇
  2024年   13篇
  2023年   76篇
  2022年   93篇
  2021年   154篇
  2020年   240篇
  2019年   343篇
  2018年   331篇
  2017年   467篇
  2016年   339篇
  2015年   399篇
  2014年   747篇
  2013年   2043篇
  2012年   1028篇
  2011年   1020篇
  2010年   900篇
  2009年   859篇
  2008年   993篇
  2007年   1147篇
  2006年   1104篇
  2005年   971篇
  2004年   862篇
  2003年   824篇
  2002年   689篇
  2001年   600篇
  2000年   390篇
  1999年   149篇
  1998年   101篇
  1997年   76篇
  1996年   76篇
  1995年   82篇
  1994年   56篇
  1993年   45篇
  1992年   38篇
  1991年   19篇
  1990年   20篇
  1989年   31篇
  1988年   17篇
  1987年   14篇
  1986年   5篇
  1985年   4篇
  1984年   10篇
  1983年   8篇
  1982年   1篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
  1976年   1篇
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
201.
Building on recent efforts to bring a socio-political perspective to social capital research, we develop and test a multilevel framework that explains why middle managers who occupy brokerage positions differ in their ability and willingness to engage in entrepreneurial behavior. More specifically, we provide a contextualized understanding of the links among middle managers' brokerage, their political-support ties, and their personal initiative. Results derived from data on 383 middle managers and 72 top managers in 34 business units indicate that political-support ties with top managers strengthen the relationship between middle managers’ brokerage and personal initiative. However, this positive effect depends on the social capital resources available in the focal business unit. It is attenuated in business units with a supportive and trusting social context and amplified in business units with high levels of internal connectedness. By uncovering these incompatibilities and complementarities, our study demonstrates the value of accounting for different social capital configurations and the interplay of their inherent social capital resources when examining the effects of brokerage on corporate entrepreneurship.  相似文献   
202.
对近十年来国内医学用途英语教学研究进展进行了整体回顾和概要总结。利用中国知网CNKI文献分析工具,对2011至2020年发表的医学用途英语学术论文进行检索统计,从发文量、文献来源、作者及机构分布、研究主题、研究视角等维度进行进展分析。研究发现,知网共发表相关主题论文342篇,其中核心期刊论文26篇,主要从医学用途英语所面临的挑战、需求分析、教学模式、教学改革、教材编写以及医学用途英语教师转型发展等视角展开讨论。研究认为未来的医学用途英语教学研究需要走“外语+医学”跨学科特色发展路径,以培养更多面向新时代的复合型医学人才。  相似文献   
203.
本文主要探讨了脉冲光源光函数的测试方法,着重介绍了利用频谱分析仪,采用比对法测试闪光型救生衣灯光函数的过程.  相似文献   
204.
Dynamic reliability models with conditional proportional hazards   总被引:1,自引:0,他引:1  
A dynamic approach to the stochastic modelling of reliability systems is further explored. This modelling approach is particularly appropriate for load-sharing, software reliability, and multivariate failure-time models, where component failure characteristics are affected by their degree of use, amount of load, or extent of stresses experienced. This approach incorporates the intuitive notion that when a set of components in a coherent system fail at a certain time, there is a jump from one structure function to another which governs the residual lifetimes of the remaining functioning components, and since the component lifetimes are intrinsically affected by the structure function which they constitute, then at such a failure time there should also be a jump in the stochastic structure of the lifetimes of the remaining components. For such dynamically-modelled systems, the stochastic characteristics of their jump times are studied. These properties of the jump times allow us to obtain the properties of the lifetime of the system. In particular, for a Markov dynamic model, specific expressions for the exact distribution functions of the jump times are obtained for a general coherent system, a parallel system, and a series-parallel system. We derive a new family of distribution functions which describes the distributions of the jump times for a dynamically-modelled system.  相似文献   
205.
利用Fourier方法得到复调和函数的混合边值问题解的表示式及解的存在性定理并讨论了解的唯一性.  相似文献   
206.
Approximation of a density by another density is considered in the case of different dimensionalities of the distributions. The results have been derived by inverting expansions of characteristic functions with the help of matrix techniques. The approximations obtained are all functions of cumulant differences and derivatives of the approximating density. The multivariate Edgeworth expansion follows from the results as a special case. Furthermore, the density functions of the trace and eigenvalues of the sample covariance matrix are approximated by the multivariate normal density and a numerical example is given  相似文献   
207.
LetX1,X2, ..., be real-valued random variables forming a strictly stationary sequence, and satisfying the basic requirement of being either pairwise positively quadrant dependent or pairwise negatively quadrant dependent. LetF^ be the marginal distribution function of theXips, which is estimated by the empirical distribution functionFn and also by a smooth kernel-type estimateFn, by means of the segmentX1, ...,Xn. These estimates are compared on the basis of their mean squared errors (MSE). The main results of this paper are the following. Under certain regularity conditions, the optimal bandwidth (in the MSE sense) is determined, and is found to be the same as that in the independent identically distributed case. It is also shown thatn MSE(Fn(t)) andnMSE (F^n(t)) tend to the same constant, asn→∞ so that one can not discriminate be tween the two estimates on the basis of the MSE. Next, ifi(n) = min {k∈{1, 2, ...}; MSE (Fk(t)) ≤ MSE (Fn(t))}, then it is proved thati(n)/n tends to 1, asn→∞. Thus, once again, one can not choose one estimate over the other in terms of their asymptotic relative efficiency. If, however, the squared bias ofF^n(t) tends to 0 sufficiently fast, or equivalently, the bandwidthhn satisfies the requirement thatnh3n→ 0, asn→∞, it is shown that, for a suitable choice of the kernel, (i(n) ?n)/(nhn) tends to a positive number, asn→∞ It follows that the deficiency ofFn(t) with respect toF^n(t),i(n) ?n, is substantial, and, actually, tends to ∞, asn→∞. In terms of deficiency, the smooth estimateF^n(t) is preferable to the empirical distribution functionFn(t)  相似文献   
208.
体词谓语句是以体词作谓语,能够自由生存的句子,它是现代汉语中一种独立的句型而非动词句的省略。体词具备陈述功能,是其作谓语的语法条件,体谓句的陈述关系,主要是由两个单独体词间的并列、偏正关系,因修饰语的参与转化而来的。从语义角度说,体谓句中主谓两部分的逻辑关系、语义制约,以类的形式出现,是句子赖以存在的基础。  相似文献   
209.
The maximum likelihood estimation for the critical points of the failure rate and the mean residual life function are presented in the case of mixture inverse Gaussian model. Several important data sets are analyzed from this point of view. For each of the data sets, Bootstrapping is used to construct confidence intervals of the critical points.  相似文献   
210.
This essay identifies parallels between the traits assigned to gender work roles and the teaching/research division of labor at research universities. The character and definition of undergraduate teaching at research universities is very similar to what has often been described as women's work.  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