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   240篇
  免费   8篇
财政金融   26篇
工业经济   10篇
计划管理   56篇
经济学   52篇
综合类   3篇
运输经济   5篇
旅游经济   5篇
贸易经济   73篇
农业经济   7篇
经济概况   11篇
  2023年   6篇
  2022年   2篇
  2021年   3篇
  2020年   9篇
  2019年   15篇
  2018年   21篇
  2017年   17篇
  2016年   11篇
  2015年   7篇
  2014年   15篇
  2013年   39篇
  2012年   13篇
  2011年   10篇
  2010年   7篇
  2009年   13篇
  2008年   6篇
  2007年   5篇
  2006年   5篇
  2005年   12篇
  2004年   5篇
  2003年   4篇
  2002年   4篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1992年   1篇
  1990年   2篇
  1988年   1篇
  1985年   1篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
排序方式: 共有248条查询结果,搜索用时 9 毫秒
1.
The simulation problem is one of the most commonly used formats in computer-assisted instruction (CAI). In medical education, a patient simulation problem is known as a patient management problem (PMP). A number of computerized PMP systems are currently available. However, to date, there is no record of PMP systems having been developed using artificial intelligence. This is noteworthy since artificial intelligence techniques could help in the generation of more effective and intelligent instructional systems.

This paper analyzes and evaluates existing instructional simulation software in clinical medicine in terms of effective educational design attributes. Components of effective PMP systems thus identified are incorporated into a computerized instructional system which uses artificial intelligence techniques for teaching problem-solving and diagnostic skills to undergraduate medical students.  相似文献   

2.
3.
This paper analyses the effects of dynamic correlations between stock and bond returns issued by the same firm on the speed of adjustment towards target leverage. The results show that the estimated correlations are time varying, show persistence and differ among firms. Analysis of the potential explanatory variables reveals that the correlations decrease with negative expectations about future aggregate risks, but only for firms with a low default probability. In contrast, correlations are positively associated with specific risk measures, especially idiosyncratic stock risk and financial leverage. The positive relationship between the correlations and the leverage ratio suggests that target leverage can be achieved faster when the stock–bond correlation is high. Our results show that this is the case.  相似文献   
4.
This paper examines the qualitative, quantitative, and geographical evolution (1987–2012) of the Blue Flag campaign and accreditation process in Spain, a leading coastal tourism destination heading the list of awards. The standard Blue Flag criteria for crowded, developed beaches are now adapting to new demands for natural beaches, but they still fail to capture essential sustainable tourism features, such as limiting user numbers, or preserving and restoring sand ecosystems. Given these shortcomings, some destinations are moving to alternative awards with a higher environmental commitment, such as EMS, ISO14001, and Eco-Management and Audit Schemes (EMAS). A cluster analysis of Blue Flag data for 983 beaches in Spain over 26 years revealed different behaviour patterns: established tourist areas that have always opted for the Blue Flag programme; tourist areas that adopted the Blue Flag early on but replaced it with ISO14001 and EMAS; recently developed destinations applying for the award to boost their tourism promotion; and tourist areas with no well-defined policy that have opted intermittently for Blue Flag. These profiles illustrate the different policies of Spain's Autonomous Regions, and they are useful for tourism managers to verify whether their destination's behaviour pattern contributes to sustainable tourism and matches strategic policies they have designed for them.  相似文献   
5.
ABSTRACT

There is growing evidence that nature-based recreation (NBR) during childhood promotes connectedness to nature, which in turn fuels NBR during adulthood. In addition to providing a number of health benefits, NBR participation may enhance leisure satisfaction, an important predictor of happiness and life satisfaction. In this exploratory study, we tested these hypothesised links using a path model with a cross-sectional sample of 224 Brazilian college students, where NBR participation during childhood increases connectedness to nature and NBR participation during adulthood, which in turn promotes leisure satisfaction. The model fit the data well χ2 (2) = 1.924, χ2/df = 0.962 (N = 220, p = .38), CFI = 1.00, AGFI = .978, GFI = .996, and RMSEA = .00, with results showing an indirect positive link between NBR during childhood and leisure satisfaction, and a direct link between NBR during adulthood and leisure satisfaction. The indirect effect of connectedness to nature on leisure satisfaction was also significant: NBR during childhood fostered connectedness to nature, which motivated NBR during adulthood and higher levels of leisure satisfaction. Leisure practitioners can improve people’s leisure satisfaction by promoting engagement in NBR activities across life stages and emphasising connection to nature.  相似文献   
6.
7.
Quality & Quantity - In infant development, maternal sensitivity is a central construct in the study of the processes involved in the caregiver-infant relationship and child attachment. The...  相似文献   
8.
This paper deals with heterogeneity and nonlinearities in the growth process by developing a two-stage strategy to identify and estimate a club convergence model with threshold externalities. Because of identification and collinearity problems, we develop an entropy-based estimation procedure which simultaneously takes account of ill-posed and ill-conditioned inference problems. First, clubs are identified by introducing a mapping structure in a conditional convergence model. Finally, we estimate a multiple club convergence model, where clubs correspond to subsets of total observations. Our procedure is applied to assess the existence of club convergence for a large sample of countries (1965–2008).  相似文献   
9.
Acquisition announcements influence the stock price of target firms, providing an opportunity for insiders to obtain significant abnormal returns. We study the presence of positive abnormal returns before the announcement date, in target firms, quoted in Euronext markets (Belgium, France, The Netherlands and Portugal) from 2001 to 2007. We investigate whether the pre-announcement run-up of prices can be explained by rumours in the media and the percentage of capital previously owned by the bidding firm, among other factors. We examine cumulative abnormal returns in an event window of 60 days prior the acquisition announcement, with the event date adjusted for the previous disclosure of news about the acquisition, in the media. We compute a run-up index, and find that there are abnormal positive returns before the announcement date, confirming previous studies. We find that a significant part of the run-up is explained by: (i) market anticipation triggered by legitimate sources of information, namely, rumours in the media about the possibility of an acquisition bid and (ii) the percentage of capital previously owned in the target firm, by the bidding firm.  相似文献   
10.
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