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   8837篇
  免费   491篇
  国内免费   94篇
财政金融   760篇
工业经济   428篇
计划管理   2145篇
经济学   1700篇
综合类   737篇
运输经济   145篇
旅游经济   213篇
贸易经济   1666篇
农业经济   698篇
经济概况   930篇
  2024年   28篇
  2023年   207篇
  2022年   177篇
  2021年   318篇
  2020年   473篇
  2019年   366篇
  2018年   321篇
  2017年   422篇
  2016年   342篇
  2015年   345篇
  2014年   614篇
  2013年   1058篇
  2012年   702篇
  2011年   728篇
  2010年   554篇
  2009年   470篇
  2008年   515篇
  2007年   409篇
  2006年   314篇
  2005年   232篇
  2004年   171篇
  2003年   152篇
  2002年   106篇
  2001年   89篇
  2000年   71篇
  1999年   40篇
  1998年   53篇
  1997年   32篇
  1996年   30篇
  1995年   18篇
  1994年   12篇
  1993年   9篇
  1992年   6篇
  1991年   5篇
  1990年   4篇
  1989年   1篇
  1988年   4篇
  1987年   3篇
  1986年   5篇
  1985年   7篇
  1984年   3篇
  1983年   3篇
  1982年   2篇
  1980年   1篇
排序方式: 共有9422条查询结果,搜索用时 31 毫秒
1.
ABSTRACT

The aviation e-service system is an important part of support for business communication in regions covered by Belt and Road initiative. In exploring the role of airline companies in this system, we examine the structure of the network, which consists of airlines interconnections based on small data of individual attributes of aviation companies in aviation e-services, and study these interconnections across different groups using block modeling. The heuristic solution of airline companies in development of international communication and cooperation is further discussed. Among our policy implications for global managers, we suggest the enhancement of cross-regional cooperation among airlines.  相似文献   
2.
Credit risk is one of the main risks faced by a bank to provide financial products and services to clients. To evaluate the financial performance of clients, several scoring methodologies have been proposed, which are based mostly on quantitative indicators. This paper highlights the relevance of both quantitative and qualitative features of applicants and proposes a new methodology based on mixed data clustering techniques. Indeed, cluster analysis may prove particularly useful in the estimation of credit risk. Traditionally, clustering concentrates only on quantitative or qualitative data at a time; however, since credit applicants are characterized by mixed personal features, a cluster analysis specific for mixed data can lead to discover particularly informative patterns, estimating the risk associated with credit granting.  相似文献   
3.
Based on the day-night PM2.5 difference of the nearest atmospheric monitoring points to measure whether there is illegal emission, this paper explores the impact of environmental protection officials' tenure (EPLT) on illegal emissions. The results show that there is a positive correlation between EPLT and illegal emissions. Stable EPLT can reduce illegal emissions by increasing environmental information disclosure and environmental subsidies. It can increase illegal emissions by weakening public pollution reporting and media supervision, environmental law enforcement and promoting corruption. In addition, EPLT can increase illegal emissions as EPLT is less than 3.55 years, while EPLT can increase illegal emissions as EPLT exceeds 6.21 years. Further, when mayor's tenure and EPLT are both stable, the promotion effect of EPLT on illegal emission is stronger. Stable company director's tenure can also aggravate the promotion effect of EPLT on illegal emissions.  相似文献   
4.
田璐玚 《科技和产业》2023,23(13):175-182
智慧居家养老服务的协同供给可以形成社会联动效应,降低公共服务成本。运用公共服务协同供给分析框架,通过交叉分类方法从协同主体的利益与目标两个变量的耦合性出发分析广西钦州市智慧居家养老项目中养老服务主体间不同种类的协同关系,可以从加强政府领导、形成合作联盟、建立市场标准、创新扶持政策4个方面完善政府、企业、社会组织之间不同类型的协同供给,实现社会资源的高效利用以及向智慧居家养老服务的发展和转变。  相似文献   
5.
This study investigates whether major USDA reports still provide important news to changing crop markets. The news component of each report, or market “surprise,” is measured as a difference between the USDA estimate and its private expectation in corn, soybeans, and wheat markets. Changes in the relevance of USDA information are assessed by examining changes in the magnitude of market surprises and shifts in the futures price reaction to these surprises, which isolates the impact of each report. The stable size of market surprises over time suggests that competition from alternative data sources has not reduced the news component of USDA crop reports. Increasing price reaction to most reports, including those facing competition from alternative information sources, suggests that value of public information may be enhanced in uncertain markets affected by structural changes.  相似文献   
6.
近年来,在线平台的迅猛发展推动了全球经济数字化加速转型,但同时也引发了包括增值税政策适用在内的诸多挑战.通过研究《欧盟增值税指令》和欧州法院的判例法,以及分析个人数据与在线平台运行之间的关系可以推断出,个人数据是在线平台提供访问服务构成的增值税应税范围内的供应,且与消费者是否向在线平台支付金钱形式的对价无关.在实践中,使用客观价值方法来确定在线服务供应的应税金额存在实际困难,而使用直接联系标准解决易货交易问题,会导致增值税税基在本质上得到扩张.因此,建议当前不要将在线平台访问服务的供应视为一项应税交易.此外,对于商家为获得消费者数据而向平台付款的情形,因其不符合直接联系标准,也不应被视为服务对价.  相似文献   
7.
我们已经进入了一个全新的大数据信息化时代,充满了更多的机遇与挑战。大数据及数字经济的出现极大程度地改变了传统技术及工作思维的方式。数字经济是继工业和农业之后的又一大经济形态,为社会的经济增长提供了新的动力。通过分析电网行业传统的科学技术及作业方式,论文简要阐述了基于大数据信息化发展下电网的影响,并认为信息化技术的发展对于数字经济有着至关重要的影响及重要性。最后论文讨论了数字经济发展存在的问题及方向。  相似文献   
8.
Systems’ thinking places high value on understanding the context. This study focused on the collection of disaggregated data in order to understand the context, to facilitate improvement of health outcomes. The aim of this article was to assess the implementation of municipal ward-based health data collection (disaggregated data) and health care workers’ perceptions of this data collection process. This cross-sectional study used mixed methods in Amajuba district. The participants were professional nurses at the Primary Health Care level. Of the 131 respondents, 123 (93.9%) collected municipal ward-based health data, and found it useful. Opportunities for improving data collection were identified. Disaggregation of the data at ward level contributes to a better understanding of the target population’s health, assists planning for health needs and enables provision of targeted interventions in order to improve health outcomes, to prevent financial regression and waste of health resources.  相似文献   
9.
Drone food delivery services play a significant role in protecting the environment, because the services are operated by batteries that can be charged with electricity. Therefore, this study tried to examine a green image in the context of drone food delivery services. More specifically, this study proposed that a green image of drone food delivery services plays an important role in the formation of attitude toward using the services. In addition, it was hypothesized that the attitude has a positive influence on behavioral intentions including intentions to use, word‐of‐mouth intentions, and willingness to pay more. Lastly, the moderating role of gender and age was proposed during the theory‐building process. A theoretical model, which included 12 hypotheses, was developed and tested using a total of 427 samples collected in Korea. The data analysis results showed that a green image of drone food delivery services has a positive influence on attitude toward using the services, which in turn positively affects three subdimensions of behavioral intentions. Furthermore, gender and age played partly as a moderator. The current paper was the first to study the green image of drone food delivery services, so the findings of this study mean a lot to the theoretical aspect.  相似文献   
10.
ABSTRACT

This article identifies the breakdowns in the covariance of three benchmark crude oil futures markets (WTI, Brent and Dubai) and investigates the changes of market connectedness across the breakdown periods. As the crude oil futures are traded in different regions, this article eliminates the non-synchronous trading data by employing the Vector Moving Average structure and the Bayesian data augmentation approach, which keeps the integrity of original data without changing its properties. The results show that there are significant breaks in the covariance structure of crude oil futures markets. The breakdown periods are consistent with the periods when the market volatilities are at high level and the returns are volatile. The changes of market connectedness are independent of the covariance states, which supports the globalization hypothesis for the crude oil market. The results also suggest that there is more information flow out of the WTI than to the WTI during the sample period, particularly during the breakdown periods in 2008–2009.  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