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   10650篇
  免费   275篇
  国内免费   2篇
管理学   1732篇
民族学   48篇
人才学   4篇
人口学   888篇
丛书文集   39篇
理论方法论   1014篇
综合类   113篇
社会学   5371篇
统计学   1718篇
  2020年   144篇
  2019年   202篇
  2018年   214篇
  2017年   265篇
  2016年   237篇
  2015年   175篇
  2014年   240篇
  2013年   1769篇
  2012年   283篇
  2011年   285篇
  2010年   238篇
  2009年   234篇
  2008年   290篇
  2007年   264篇
  2006年   291篇
  2005年   294篇
  2004年   235篇
  2003年   212篇
  2002年   232篇
  2001年   225篇
  2000年   221篇
  1999年   199篇
  1998年   187篇
  1997年   154篇
  1996年   157篇
  1995年   157篇
  1994年   184篇
  1993年   173篇
  1992年   178篇
  1991年   195篇
  1990年   210篇
  1989年   174篇
  1988年   190篇
  1987年   169篇
  1986年   156篇
  1985年   173篇
  1984年   180篇
  1983年   158篇
  1982年   124篇
  1981年   99篇
  1980年   100篇
  1979年   125篇
  1978年   105篇
  1977年   85篇
  1976年   96篇
  1975年   64篇
  1974年   91篇
  1973年   61篇
  1972年   50篇
  1971年   50篇
排序方式: 共有10000条查询结果,搜索用时 484 毫秒
801.
Discussions concerning low trust scores in politics and politicians (both refer to a lack of political interest and activity), increasingly focus attention on how, in particular, adolescents relate trust to political activity. Younger people are said to show a lack of political interest. Nevertheless empirical studies about the determinants of missing political commitment and about the combination of trust and political action are extremely rare. Therefore, this empirical study focuses on the impact of trust on juveniles‘ political involvement. The question which characteristics trustworthy politicians must have in adolescents‘ eyes, and if relevant interindividual differences do exist, is of special regard.  相似文献   
802.
Transportation planning today involves all modes—airways, railways, roadways, waterways, and pipelines. Even the transmission of electrical power may be considered as a mode of transportation. Moreover, transportation planning involves the economic, political, and social systems of a nation. This paper is an attempt to create an awareness of the vast importance and complexity of transportation planning, to define a potential role of transportation, and finally, to suggest ways and means of achieving transportation's possible role.  相似文献   
803.
To be efficient, logistics operations in e‐commerce require warehousing and transportation resources to be aligned with sales. Customer orders must be fulfilled with short lead times to ensure high customer satisfaction, and the costly under‐utilization of workers must be avoided. To approach this ideal, forecasting order quantities with high accuracy is essential. Many drivers of online sales, including seasonality, special promotions and public holidays, are well known, and they have been frequently incorporated into forecasting approaches. However, the impact of weather on e‐commerce operations has not been rigorously analyzed. In this study, we integrate weather data into the sales forecasting of the largest European online fashion retailer. We find that sunshine, temperature, and rain have a significant impact on daily sales, particularly in the summer, on weekends, and on days with extreme weather. Using weather forecasts, we have significantly improved sales forecast accuracy. We find that including weather data in the sales forecast model can lead to fewer sales forecast errors, reducing them by, on average, 8.6% to 12.2% and up to 50.6% on summer weekends. In turn, the improvement in sales forecast accuracy has a measurable impact on logistics and warehousing operations. We quantify the value of incorporating weather forecasts in the planning process for the order fulfillment center workforce and show how their incorporation can be leveraged to reduce costs and increase performance. With a perfect information planning scenario, excess costs can be reduced by 11.6% compared with the cost reduction attainable with a baseline model that ignores weather information in workforce planning.  相似文献   
804.
The progeny of the affected and non-affected dams in the bovine spongiform encephalopathy (BSE) cohort study were paired in terms of their farm of origin and approximate date of birth. This paper presents an exact logistic regression analysis that avoids modelling the differences between the pairs and so analyses only the discordant pairs. There is some evidence that the pairs in which the affected animal was born to the affected dam tend to be those in which the onset of BSE in the affected dam preceded or occurred soon after the calving. This suggests some occurrence of maternal transmission.  相似文献   
805.
The Kaplan–Meier estimator of a survival function requires that the censoring indicator is always observed. A method of survival function estimation is developed when the censoring indicators are missing completely at random (MCAR). The resulting estimator is a smooth functional of the Nelson–Aalen estimators of certain cumulative transition intensities. The asymptotic properties of this estimator are derived. A simulation study shows that the proposed estimator has greater efficiency than competing MCAR-based estimators. The approach is extended to the Cox model setting for the estimation of a conditional survival function given a covariate.  相似文献   
806.
A survey of statewide public agencies shows that a majority of states have some form of judicial or administrative periodic review, although few have both. The organizational level of authority and degree of foster care specialization of agencies are positively correlated with administrative review and negatively correlated with judicial review.  相似文献   
807.
Seven task-oriented teams worked together forbetween 4 and 6 months on a project. At the end of thetask, members were each subject to four task-performanceratings: from self, superior, team-peers, and a consultant who was part of the team. Therewere fewer than chance differences between the differentteams on the congruence measures so the data wascombined. While the congruence between self and manager, self and peer, and self and consultant ratingswere very low, the manager peer, manager consultant, andpeer consultant congruence was overall high. Observablebehaviors like forward planning and communication showed overall highest congruence while lessobservable cognitive variables showed much lowercongruence. These results are similar to previousstudies in the area. Implications of the use of theseratings in management development areconsidered.  相似文献   
808.
The Emerson (1968, Biometrics 24 , 695–701) recurrence relation has many important applications in statistics. However, the original derivation applied only to discrete distributions. In the following, a simple derivation is given that generalizes the Emerson recurrence relation to any distribution for which the necessary expectations exist. A modern application is outlined.  相似文献   
809.
This article conceptualizes and empirically examines buyer–supplier relationships in respect of supply sourcing strategies, relationship characteristics and firm performance. Two sourcing strategies available to organizations are examined, critical and leverage, which in turn, influence the approach to managing the supplier relationship (arms‐length or collaborative). We argue that different relationship approaches are appropriate to achieving different performance outcomes. A structural equation model, using a sample of 142 manufacturing firms based in the United Kingdom, is used to test this hypothesized model. The results indicate that a critical sourcing strategy requires collaborative supplier relationships in order to achieve higher relationship and business outcomes, while leverage sourcing strategies have a direct impact on these same performance outcomes. In addition, a leverage strategy was associated with increased levels of supplier power, though this power was found not to have a significant effect on performance. Our study provides support for the importance of aligning sourcing strategies to particular supplier relationship approaches in order to improve firm performance. Managerial implications of these findings and future directions for research are then offered.  相似文献   
810.
In a semantic text analysis the researcher begins by creating one of two types of semantic grammars, each of which provides one or more templates that specify the ways concepts (or more general themes) may be related. On the one hand, a phenomenal semantic grammar can be created to extract phenomenon-related information from a text population (e.g., "Among the population's grievances [the phenomenon of interest in this case], which were ones for the abolition of taxes?"). On the other hand, a generic semantic grammar may be developed to yield data about the text population itself (e.g., "Among all clauses in the text population, how many were grievances for the abolition of taxes?"). This paper describes a generic semantic grammar that can be used to encode themes and theme relations in every clause within randomly sampled texts. Unlike the surface-grammatical relations mapped by syntax grammars, the theme relations allowed in this grammar only permit unambiguous encoding according to the meanings that clauses were intended to convey within their social context. An application of the grammar provides a concrete illustration of its research potential.  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