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   5017篇
  免费   146篇
  国内免费   13篇
财政金融   623篇
工业经济   324篇
计划管理   974篇
经济学   981篇
综合类   520篇
运输经济   38篇
旅游经济   28篇
贸易经济   598篇
农业经济   332篇
经济概况   743篇
信息产业经济   4篇
邮电经济   11篇
  2024年   8篇
  2023年   43篇
  2022年   89篇
  2021年   100篇
  2020年   140篇
  2019年   103篇
  2018年   77篇
  2017年   125篇
  2016年   101篇
  2015年   125篇
  2014年   184篇
  2013年   239篇
  2012年   367篇
  2011年   579篇
  2010年   515篇
  2009年   380篇
  2008年   360篇
  2007年   362篇
  2006年   383篇
  2005年   384篇
  2004年   130篇
  2003年   106篇
  2002年   81篇
  2001年   81篇
  2000年   42篇
  1999年   19篇
  1998年   9篇
  1997年   10篇
  1996年   7篇
  1995年   3篇
  1994年   2篇
  1993年   4篇
  1992年   4篇
  1991年   2篇
  1989年   4篇
  1988年   1篇
  1984年   7篇
排序方式: 共有5176条查询结果,搜索用时 156 毫秒
1.
This paper examines the international trade of a variety of genetically modified (GM) food products over a 27-year period (1984–2011) with data from the United Nations using the tools of social network analysis. The results indicate that each of the different crops have a distinctive pattern of trade that has changed over time due to a number of different factors. Also, trade in agricultural commodities became more diversified over time, dominated less by the United States and other nations central in the trade networks and trade in the individual GM crops was stable over time. Countries maintained their trading partners for specific crops, despite the adoption of the genetically modified varieties. The economic implications of these results are discussed for specific countries.  相似文献   
2.
Previous research has shown that virtuous leader behavior in the form of benevolent leadership has considerable impact on employee creativity. However, little is known as to how and under what conditions these constructs are linked. In the current research, we proposed and tested a moderated mediation model positing leader–member exchange (LMX) as a mediator, and employee power-distance orientation as a moderator of this relationship. Two studies were conducted to test our hypothesized model. In Study 1, repeated measured data collected from 284 Chinese employees in an information technology company demonstrated that benevolent leadership had a lagged effect on LMX. In Study 2, analyses of multisource and lagged data from 391 Chinese employees in 42 research and development teams, and their direct supervisors indicated that benevolent leadership was positively related to supervisor-rated employee creativity via LMX. In addition, the relationship between benevolent leadership and LMX was stronger for employees high in power-distance orientation. Theoretical implications of benevolent leadership’s research and practical contributions concerning promoting creativity in organizations where benevolent leaders prevail are also discussed.  相似文献   
3.
Objective: In Japan, the National Immunization Program (NIP) includes PPV23 as the primary vaccination for adults and catch-up cohorts. The Japanese Association for Infectious Diseases recommends revaccination for older adults who received primary vaccination ≥5 years earlier. The cost-effectiveness of adding revaccination and/or continuing catch-up vaccination in the NIP was evaluated from the public payer perspective in Japan.

Methods: The Markov model included five health states: no pneumococcal disease, invasive pneumococcal diseases (IPD), non-bacteremic pneumococcal pneumonia (NBPP), post-meningitis sequelae, and death. Cohorts of adults aged 65–95 were followed until age 100 or death: 2014 cohort (aged 65–95, vaccinated: 2014); 2019 cohort (aged 65: 2019); and 2019 catch-up cohort (aged 70–100: 2019, unvaccinated: 2014). Strategies included: (1) vaccinate 2014 and 2019 cohorts; (2) vaccinate 2014 and 2019 cohorts and revaccinate both; (3) strategy 1 and vaccinate 2019 catch-up cohort; (4) strategy 2 and vaccinate 2019 catch-up cohort; and (5) strategy 4 and revaccinate 2019 catch-up cohort. Parameters were retrieved from global and Japanese sources, costs and QALYs discounted at 2%, and incremental cost-effectiveness ratios (ICERs) estimated.

Results: Strategy 1 had the highest number of IPD and NBPP cases, and strategy 5 the lowest. Strategies 3–5 dominated strategy 1 and strategy 2 was cost-effective compared to strategy 1 (ICER: ¥1,622,153 per QALY gained). At a willingness-to-pay threshold of ¥5 million per QALY gained, strategy 2 was cost-effective and strategies 3–5 were cost-saving compared to strategy 1.

Conclusions: Strategies including revaccination, catch-up, or both were cost-effective or cost-saving in comparison to no revaccination and no catch-up. Results can inform future vaccine policies and programs in Japan.  相似文献   
4.
We study investor communication and stock comovement using a novel data set from an active online stock forum in China. We find substantial comovement among the returns of a stock and its “related stocks,” which are frequently discussed in the subforum dedicated to the given stock. Comovement is greater when the discussion of related stocks is more intensive. Further, the effect of communication on comovement is stronger for stocks associated with higher information uncertainty. Codiscussed stocks are more actively traded and experience more correlated trading. A trading strategy that exploits communication‐driven comovement generates abnormal returns. Our findings highlight the impact of investor communication on asset comovement.  相似文献   
5.
Most studies on the predictability of moving average (MA) technical analysis use the discrete (buy/sell) trading recommendations. However, it is possibly incomplete or unreliable to explore the predictability of MA by only employing its generated trading signals. To further explore the forecastability of MA, we study its measurable impact on the stock market returns by using a conventional predictive regression framework. Our empirical study on the US stock market with respect to more detailed price information finds, (i) that the proposed predictor, MADP (MA based on daily prices) shows significant predictability in‐ and out‐of‐sample, and significantly outperforms the historical average (HA) benchmark as well as the MA based on monthly prices, (ii) that the predictability of MADP centers on the short‐term lags (within the most recent 10 days) and disappears when lags are beyond 20 days, and (iii) that the economic evaluation of the portfolios based on trading strategies confirms the superior performance of MADP with short‐term lags against the benchmark even though considering transaction costs.  相似文献   
6.
目前理论界对金融监管存在着几个需要澄清的理论误区.中国金融监管存在着体制缺陷和信息黑洞,制约着监管效率的提高.因此,中国金融监管效率的提高,关键在于改革中国金融监管体制,在于形成金融监管当局提供有效监管的激励及其相应的制度安排.  相似文献   
7.
“加快建立现代企业制度,实现企业制度创新;加快主辅分离,促进剥离改制;加快技术进步,提高创新能力”是煤炭企业改革发展关键之所在……  相似文献   
8.
我国保税区的发展已进入战略调整与体制转型的关键时期,无论是区域扩张、港区联动,还是企业运营,都对其金融环境的完善提出了新的要求.为此,应在对保税区金融服务进行评价的基础上,从软环境和硬环境两个方面,探讨转型过程中保税区金融环境重构的战略措施.  相似文献   
9.
主持人目前,电子标签已广泛应用于烟草、医药、化工、服装、图书、机械、电子等行业的拣选和配送作业,并且由于其无与伦比的便利性,应用范围在不断扩大,其用途逐渐突破以前单纯的拣选和配送业务,扩展到分类、标识、导引、控制等方面。但是,还有很多企业对电子标签拣货系统的特点、类  相似文献   
10.
多媒体教学的探讨   总被引:10,自引:0,他引:10  
现代多媒体教学的特点是信息容量大,形象直观,生动有趣,交互性强,具有很强的吸引力。是现代教育技术的重要内容之一,也是教育现代化的显著标志之一。但在教学实践中,却存在着种种误区,影响了多媒体教学效果的发挥。本文分析了这些误区的产生,并在此基础上提出了改进的原则和措施。  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