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   6207篇
  免费   415篇
  国内免费   53篇
财政金融   572篇
工业经济   322篇
计划管理   1730篇
经济学   1262篇
综合类   463篇
运输经济   99篇
旅游经济   124篇
贸易经济   1074篇
农业经济   447篇
经济概况   582篇
  2024年   19篇
  2023年   152篇
  2022年   131篇
  2021年   247篇
  2020年   361篇
  2019年   304篇
  2018年   261篇
  2017年   296篇
  2016年   248篇
  2015年   254篇
  2014年   443篇
  2013年   642篇
  2012年   451篇
  2011年   459篇
  2010年   355篇
  2009年   285篇
  2008年   324篇
  2007年   305篇
  2006年   240篇
  2005年   193篇
  2004年   139篇
  2003年   131篇
  2002年   96篇
  2001年   75篇
  2000年   64篇
  1999年   34篇
  1998年   47篇
  1997年   26篇
  1996年   24篇
  1995年   15篇
  1994年   11篇
  1993年   8篇
  1992年   7篇
  1991年   5篇
  1990年   4篇
  1989年   1篇
  1988年   4篇
  1987年   3篇
  1986年   4篇
  1985年   4篇
  1983年   2篇
  1980年   1篇
排序方式: 共有6675条查询结果,搜索用时 31 毫秒
911.
Developing countries today have become more active participants in regional trade agreements. This raises questions about how the benefits of integration are distributed, and the extent to which lower‐income countries are able to capture development gains. Historically, such impacts have been difficult to identify with precision. This paper seeks to address this gap by empirically analysing the impact of regional integration on development, particularly the effects on growth and welfare. Using both bilateral and regional integration measures, we show that the ability to capture gains from integration varies across developing country regional groups, with developing Asia benefiting on par with developed countries. The findings in the paper indicate that trade and trade policy play an important role in reducing inequality and poverty in developing countries. It also shows that regionalism can function as a channel to make multilateralism a more adept way of addressing national challenges.  相似文献   
912.
现代桥梁工程中高墩桥梁屡见不鲜,桥墩垂直度已成为评定桥墩施工质量的重要指标之一.以新疆某特大桥项目为依托,针对高墩垂直度检测结果实用性低的问题,提出一种采用三维激光扫描技术对高墩垂直度进行非接触测量分析的方法.利用三维激光扫描仪快速获取高墩结构全局点云信息,对桥墩点云进行拼接、降噪等预处理,采用编程算法实现了桥墩节段中心点和垂直度偏差的计算,并得到了垂直度偏差变化规律图.最后将该方法与传统方法进行对比.结果表明:利用三维激光扫描技术对高墩进行快速测量,能够获取桥墩中心轴线的三维空间线型,精确分析并定位最大偏差位置,显著提高垂直度测量结果的实用性,具有良好的工程应用前景,并为后续研究桥墩垂直度问题提供了新思路.  相似文献   
913.
Although many industries have benefited from advances in data-driven technology, education is making small steps in capitalizing on the huge potential of data systems. Since 2005, the U.S. Federal Government has been making large grants to help states build statewide longitudinal data systems (SLDS) with the goal of improving programme and teacher evaluation and engage in data-driven decision-making. We analyse whether the introduction of SLDSs improved student performance, measured using test scores for math and reading tests for 4th and 8th graders, as well as high school graduation rates. We find no effects of SLDSs on student performance up to 10 years from implementation. However, we find suggestive evidence that these systems may have long-run effects, emphasizing the long-run nature of educational data collection and policy analysis.  相似文献   
914.
ABSTRACT

We propose a new approach for tracing the so-called ‘value-added-(re)distribution-important coefficients’ (in short the VARDI coefficients) in a world input–output model. From the perspective of a selected group of economies, VARDI coefficients may be defined as those elements in world input–output matrix in the case of which a small change in their levels leads to the maximization of a share of this group of economies in value added in global value chains. Due to the rapid development of the World Input Output Database, this approach may be easily applied in empirical research to different groups of countries and sectors in world IO models. In an illustrative empirical case study, we use the new approach in order to answer a question regarding what the main directions of the future macroeconomic policy of the U.S. could be in order to ensure the maximization of the country’s share in global value added.  相似文献   
915.
The field of aviation research is entering the era of big data. While data-driven advancements in aviation have clearly brought about applicable models and results with immediate implications, we argue that the influx of aviation data should be better characterized and documented to enable more efficient and standardized usage. To this end, we examine 200 well-cited research articles from sub-disciplines ranging from revenue management to air traffic control published on or after 2010 in order to analyze the diversity, availability, tractability, applicability, and sources (DATAS) of data utilized in aviation research. We find high levels of data diversity within aviation research, with 16 data categories ranging from air traffic flow management-type data to data from distributed sensors in line with the Internet-of-Things (IoT) paradigm. We identified a dominance of proprietary, non-public data in aviation research, with 68% of the 200 research articles utilizing solely proprietary data in deriving their results, and a further 8% utilizing a mixture of proprietary and publicly available data. The pervasiveness of proprietary data has implications on reproducibility and extending research results. We also highlight the increasing tractability of the data by surveying the computational power required to process the data sets, and present vignettes of applications and results that stem from these data-driven studies. Finally, we propose several recommendations regarding standardizing data source nomenclature as well as increasing the availability of and usage of publicly available data.  相似文献   
916.
917.
The purpose of the research is to identify different consumption styles based on a large collection of letters to Santa written by some children and/or their families and submitted to the French Post website (La Poste). One of our main interests focuses on the presence and weight of brands and licenses in children’s wish lists. We have had access to all the anonymous posts sent to Santa Claus through La Poste’s website during the 2013 and 2014 Christmas holidays. We analyzed the nature of the wish lists as shown in the 43,000‐post database using several textual data analysis techniques. Extensive heterogeneity was found among children’s and families’ postures regarding that specific ritual. The different types of emails reflect the meaning families associate with Christmas time but also their different consumption styles or attitudes toward consumption: reasoned, educational, hedonistic, or materialistic, for example. When focusing on brands and licenses, we can also observe significant differences in the way families and children include them in their consumption decisions. Brands could have a very different weight in Christmas wish lists and their natures reflect different value transmission modes. The French market for Christmas children brands is rather stable and focuses on a few top leading global brands such as Playmobil, Barbie, or Lego. At least one of the ten leading brands is mentioned in half of evaluated Christmas wish lists. The analysis confirms that brands are very clearly gendered and associated with the children’s ages. Peak time for brand desire is alleged to be reached between the age of 7 and 9. To our knowledge, our research is the first to analyze a large sample of spontaneous data to capture children’s consumption styles and attitudes toward brands. Because of our classification, a first typology of parental consumption styles has also been identified.  相似文献   
918.
在智慧校园中,各种计算机网络、云计算以及移动互联网等技术大大方便了校内师生的日常生活与学习工作。各类大数据共享和交换平台、统一身份认证管理等功能为学校管理提供助力。对于高校来说,需要认真思考大数据时代下高校智慧校园服务平台建设,对此论文展开了深入研究。  相似文献   
919.
战术面向服务架构(TSOA)是实现战术云平台服务基础设施的重要支撑概念。由于战术环境的复杂性,目前对TSOA实施过程中面临问题和相关实现技术的总结还较少。为此,开展了针对TSOA的概念以及相关技术的研究。首先,从战术环境下的TSOA架构需求背景出发,介绍了TSOA架构的组成以及适应性特征;然后,通过分析战术环境下设备和网络等多方面存在的限制性因素,明确实施TSOA架构所面临的挑战以及需要解决的关键问题,并对实现过程中涉及的服务发现、消息传输机制、网络状态自适应等相关技术进行归纳;最后,对国内外的相关研究工作进行总结,期望对推动TSOA架构的具体实施提供一定参考。  相似文献   
920.
We present a machine-learning method for sentiment indicators construction that allows an automated variable selection procedure. By means of genetic programming, we generate country-specific business and consumer confidence indicators for thirteen European economies. The algorithm finds non-linear combinations of qualitative survey expectations that yield estimates of the expected rate of economic growth. Firms’ production expectations and consumers’ expectations to spend on home improvements are the most frequently selected variables – both lagged and contemporaneous. To assess the performance of the proposed approach, we have designed an out-of-sample iterative predictive experiment. We found that forecasts generated with the evolved indicators outperform those obtained with time series models. These results show the potential of the methodology as a predictive tool. Furthermore, the proposed indicators are easy to implement and help to monitor the evolution of the economy, both from demand and supply sides.  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