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   14684篇
  免费   201篇
  国内免费   38篇
管理学   1663篇
劳动科学   7篇
民族学   159篇
人才学   17篇
人口学   2493篇
丛书文集   653篇
理论方法论   773篇
综合类   3295篇
社会学   4570篇
统计学   1293篇
  2024年   3篇
  2023年   10篇
  2022年   59篇
  2021年   58篇
  2020年   47篇
  2019年   33篇
  2018年   1694篇
  2017年   1723篇
  2016年   1149篇
  2015年   166篇
  2014年   185篇
  2013年   226篇
  2012年   506篇
  2011年   1401篇
  2010年   1307篇
  2009年   1019篇
  2008年   1037篇
  2007年   1236篇
  2006年   188篇
  2005年   426篇
  2004年   422篇
  2003年   520篇
  2002年   598篇
  2001年   425篇
  2000年   227篇
  1999年   63篇
  1998年   23篇
  1997年   26篇
  1996年   50篇
  1995年   20篇
  1994年   14篇
  1993年   14篇
  1992年   10篇
  1991年   5篇
  1990年   7篇
  1989年   6篇
  1988年   12篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1983年   2篇
  1982年   2篇
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
301.
注入蒸汽在水平井筒内流动时,蒸汽沿着水平段的质量流量越来越小,且加速度压降不等于零,导致蒸汽的物性参数发生变化,而蒸汽物性对井筒内蒸汽的沿程参数分布有较大影响。依据质量守恒和能量守恒,建立了注入蒸汽干度沿水平段的变化方程,利用动量守恒原理,推导了沿水平井筒的蒸汽干度分布和压力分布计算公式,构建了摩擦力做功、湿蒸汽混合物密度、水平段吸汽量和井筒与油层之间的热传递计算模型,模型同时考虑了变质量流与蒸汽PVT参数的变化对计算结果的影响,采用按压力增量迭代的计算方法对模型进行求解。实例的模型计算结果与油藏数值模拟结果对比表明,新模型具有较高的计算精度。  相似文献   
302.
In France over the last four decades increasing interest in the small, the specific and the subjective can be observed. This involves a shift away from a holist approach towards social analysis focused on the individual and often carried out by researchers as specified and reflexive individuals. To be understood, this movement must be situated in the context of the development of French sociology, largely dominated at its origins by Durkheimian sociology. Thus, when the individual has appeared this is often not in his or her own right, but as representative of a social trend or group. As from the 1980s, new perspectives, very often imported from American sociology bring into play individual action, emotions and bodies, often studied as socially shaped. More recently, individual characteristics have been examined as a constraint on the possibilities of action, and discussion has also revolved around the reality of the person as an autonomous subject.  相似文献   
303.
This paper investigates the influence of accounting standards on systematic earnings understatement. To isolate the effect of reporting regulations from those of other institutional drivers of earnings management, Holthausen (2003) proposes analyzing reporting practices in a country undergoing a transition in accounting standards. We respond to this call by analyzing earnings management practices of large German-listed companies before and after their transitions from German GAAP to IFRS. Specifically, we focus on Big Bath behavior following Chief Financial Officer turnovers between 1999 and 2006. Our findings provide evidence of the effect of accounting standards on the existence of this particular earnings understatement pattern. However, while we detect Big Bath behavior for our sample of German GAAP firms, we find no such indication for those firms reporting under IFRS. Controlling for alternative explanations such as self-selection bias does not change our findings. We conclude that accounting standards seem to have a considerable influence on earnings management behavior, independent of managers’ and auditors’ incentives.  相似文献   
304.
We employ cross-sectional microdata from 2010 through 2012 collected by the Italian National Institute of Statistics to investigate the proposed conceptual framework regarding the joint relationship between education, life satisfaction and the probability of social trust. The analysis has been carried out using two alternative specifications of the logit model: parametric and semiparametric. Our findings suggest that (a) both modelling methods that we utilise yield consistent results in terms of the positive effects of education and life satisfaction on social trust; (b) for unsatisfied individuals, social trust is generally low and largely unresponsive to the individual’s education level, whereas for ‘sufficiently satisfied’ individuals, social trust increases strongly with education; (c) there are some gender differences in the joint relationship between education, life satisfaction and social trust and (d) the parametric approach tends to mask some interesting patterns that are captured by the semiparametric specification. This finding implies that the parametric approach leads to a biased interpretation of the results, with an apparent failure of some of the assumptions made in the conceptual framework.  相似文献   
305.
Kriging models have been widely used in computer experiments for the analysis of time-consuming computer codes. Based on kernels, they are flexible and can be tuned to many situations. In this paper, we construct kernels that reproduce the computer code complexity by mimicking its interaction structure. While the standard tensor-product kernel implicitly assumes that all interactions are active, the new kernels are suited for a general interaction structure, and will take advantage of the absence of interaction between some inputs. The methodology is twofold. First, the interaction structure is estimated from the data, using a first initial standard Kriging model, and represented by a so-called FANOVA graph. New FANOVA-based sensitivity indices are introduced to detect active interactions. Then this graph is used to derive the form of the kernel, and the corresponding Kriging model is estimated by maximum likelihood. The performance of the overall procedure is illustrated by several 3-dimensional and 6-dimensional simulated and real examples. A substantial improvement is observed when the computer code has a relatively high level of complexity.  相似文献   
306.
We investigate organizational determinants and performance effects of formal target agreements for employees based on the IAB establishment panel, a representative panel of German establishments. The results show that establishments with a high employee turnover rate, a large proportion of temporary workers, and a highly qualified workforce are significantly more likely to implement target agreements. Also, establishments with works councils installed are more likely to do so, controlling, among others, for firm size. Concerning organizational performance, we apply a first-difference and a fixed effects approach and find that establishments that implement target agreements achieve around 5 % higher total sales compared to firms that did not introduce this practice. Hence, organizations seem to benefit from the implementation of formal target agreements for employees.  相似文献   
307.
Massive increase in crimes has coexisted with rising inflation and high unemployment for the last couple of decades especially during democratic governments in Pakistan. In this paper, we explore the relationship between crime rate, misery index and democracy in Pakistan from 1975 to 2013. Granger causality test proposed the unidirectional causality running from misery index to crime rate in Pakistan. Estimating the crime function via Pasaran’s conditional error correction model, we found the significant long run equilibrium relationship between Okun’s misery index and crime rate which implies that rising inflation and unemployment rate are the major driving forces towards increasing crime rates in Pakistan. Finally, empirical evidence from Okun’s misery index suggested that people are three times more miserable in quasi democratic periods than that of dictatorship. The Barrow’s misery index model verifies that people are twice worsening in quasi democratic periods. Likewise, reported crimes are nearly twice during quasi democracy than quasi dictatorship. The crime model provided the evidence that people during quasi democratic governments are more likely tending towards crime as compared to quasi dictatorship during the study period in Pakistan. This implicitly advocates the fact that half hearted efforts and ill structured apparatus of democracy can augment the tendency of crime and misery rather than solution of such concerns of the economy.  相似文献   
308.
This paper focuses on coaching and similar types of consulting in the field of personnel development. First the author discusses the current debate concerning personnel development; finally she describes the special goals, target-groups and issues of coaching, clinical supervision, mediation, mentoring and outplacement-consulting within the field of personnel development.  相似文献   
309.
We present tight upper and lower bounds for the traveling salesman path through the points of two-dimensional modular lattices. We use these results to bound the traveling salesman path of two-dimensional Kronecker point sets. Our results rely on earlier work on shortest vectors in lattices as well as on the strong convergence of Jacobi–Perron type algorithms.  相似文献   
310.
This study considers an evacuation problem where the evacuees try to escape to the boundary of an affected area, which is convex, and a grid network is embedded in the area. The boundary is unknown to the evacuees and we propose an online evacuation strategy based on the Fibonacci sequence. This strategy is proved to have a competitive ratio of 19.5, which is better than the best previously reported result of 21.  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