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   7479篇
  免费   362篇
  国内免费   109篇
财政金融   644篇
工业经济   349篇
计划管理   1699篇
经济学   1566篇
综合类   985篇
运输经济   67篇
旅游经济   164篇
贸易经济   1092篇
农业经济   522篇
经济概况   862篇
  2024年   11篇
  2023年   139篇
  2022年   131篇
  2021年   186篇
  2020年   272篇
  2019年   221篇
  2018年   205篇
  2017年   245篇
  2016年   257篇
  2015年   234篇
  2014年   471篇
  2013年   794篇
  2012年   621篇
  2011年   737篇
  2010年   574篇
  2009年   462篇
  2008年   467篇
  2007年   441篇
  2006年   329篇
  2005年   252篇
  2004年   181篇
  2003年   148篇
  2002年   105篇
  2001年   121篇
  2000年   66篇
  1999年   64篇
  1998年   39篇
  1997年   40篇
  1996年   34篇
  1995年   7篇
  1994年   15篇
  1993年   13篇
  1992年   8篇
  1991年   12篇
  1990年   8篇
  1989年   5篇
  1988年   7篇
  1987年   1篇
  1986年   3篇
  1985年   6篇
  1984年   8篇
  1983年   2篇
  1982年   4篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
排序方式: 共有7950条查询结果,搜索用时 15 毫秒
1.
孙金波 《科技和产业》2021,21(4):284-289
国产某型民用通勤类飞机为了取得欧洲航空安全局(EASA)型号合格证,机上座椅需进行设计更改并补充进行应急着陆情况下的动态要求符合性验证.通过对适航条款及相应标准的解读,研究了基于动态试验的航空座椅动态要求适航验证技术,其主要包括座椅动态性能基本要求、试验构型及工况筛选、试验规划、合格判据和试验结果分析等内容.结果表明,该型机旅客座椅满足适航规章对座椅的动态性能要求.该项旅客座椅动态性能试验的成功为型号取得EASA型号合格证奠定了良好的基础,该型飞机也即将成为第一个取得欧洲型号合格证的国产飞机.  相似文献   
2.
The Great East Japan Earthquake created health hazards for many people. Using Panel Data gathered in Iwanuma city, Japan, at two points in time (in 2010 before the quake, and in 2013 after the quake), we found that the high degree of housing damage negatively affected victims’ self rated health (SRH) (direct effect), and decreased the levels of their social connections, which in turn also had a harmful effect on their SRH (indirect effect). We also found that although the direct impacts of earthquakes disappear relatively quickly, the harmful indirect effects associated with a decrease in social connections are slower to dissipate. We conducted a first-difference two-step GMM estimation to consider the possible problem of endogeneity. The results support the above conclusion, and show that in the short-term, the indirect impacts of the earthquake accounted for 55 % of all the impacts experienced.  相似文献   
3.
Interest in supporting local and regional food systems is rising and food hubs have attracted considerable attention among Federal, State, and local policymakers. This study explores the problem of endogenous hub location in fresh produce value chains in the Northeastern United States. To overcome limitations in the literature, we incorporate the effects of economies of scale and production seasonality into our models. Three experimental models are designed to examine the effects of alternatively applying yearly, quarterly, and monthly data on model solutions. We explicitly assess how interactions of scale economies and seasonality influence the structure and spatial attributes of an optimal regional produce aggregation hub system. The three models generate marketed different solutions and in many respects they lead to different conclusions about developing local/regional supply chains. The monthly model allows for production seasonality and actual hub operation cycle frequency and thus leads to more efficient hub solution with rich policy implications.  相似文献   
4.
Sex and tourism has long been understudied. Little is known about tourists' motivations for consuming commercial sex while travelling, and even less, if indeed anything, is known about that of Chinese outbound tourists in particular. Based on twenty interviews and two surveys with a sample of 534 male Chinese tourists who had engaged in commercial sex when travelling overseas in the previous 12 months, this study aimed first to explore why male Chinese tourists travelled overseas and purchased commercial sex, and second to construct a comprehensive scale for measuring male tourists’ motivations for overseas commercial sex. With acceptable reliability and validity, the measurement scale yielded in this study consisted of eight motivation dimensions labelled as socialisation, relaxation and escape, travel-related novelty, sexual desire fulfillment/excitement seeking, sex-related learning, sexual mastery, social prestige, and business/pragmatic purpose. Both the theoretical and methodological implications related to the developed scale are also discussed.  相似文献   
5.
This paper considers a Lagrange multiplier (LM) based panel unit root test that allows for heterogeneous structural breaks in both the intercepts and slopes of a series. We note that many popular time series variables are likely to exhibit changing means and/or trends over time. Given that the usual tests will depend on the nuisance parameters indicating the locations of the trend breaks, we adopt a transformation procedure that makes our new panel unit root tests invariant to the nuisance parameters. To illustrate the importance of the power gain provided by our test, we examine the convergence hypothesis using relative ratios of per capita health care expenditures in 20 OECD countries. Our results provide evidence that the convergence hypothesis is supported.  相似文献   
6.
The centrality of cross‐functional integration (CFI) to supply chain theory and practice has long been recognized. Yet researchers continue to struggle with consistently defining or measuring the CFI construct, thus limiting the utility of CFI research. This research develops (1) a comprehensive definition of CFI that synthesizes previous supply chain research and (2) a valid set of scale items that measure the conceptual domain outlined by this definition. The goal is to build a common foundation for extending knowledge on CFI's antecedents and consequences, and ultimately to improve scholars’ ability to guide a broader practitioner community still struggling to achieve integration in their organizations.  相似文献   
7.
What if a popular dataset that has generated a large amount of literature has been misunderstood and has led to misleading inferences? This paper examines household expenditure data from the Indonesian National Socio-economic Survey (Susenas), which started more than 50 years ago. Appropriate use of Susenas data for policy analysis requires an understanding that the survey’s expenditure variable does not measure true out-of-pocket expenses, because it includes subsidies received by households when obtaining goods and services. We also highlight an abrupt change in the survey instrument that occurred in 2015, when the reference period for certain items was extended. For health items, this generated a change in the expenditure series that can be misinterpreted as being the result of a social health insurance reform introduced in 2014 to lower the health care burden on households. Accordingly, we propose a way to account for this artificial expenditure movement in Susenas.  相似文献   
8.
We re-examine the representative agent's optimal consumption and savings under uncertainty in the presence of investment constraints using martingale representation and convex analysis techniques. This framework allows us to explicitly quantify precautionary savings which induces a higher average growth rate than in a certainty setup. We provide a closed form solution for a Cobb-Douglas economy. The effect of uncertainty on portfolio selection is analyzed. Consumption growth rate and risk free interest rate exhibit a U-shaped relationship. Uncertainty negatively affects expected consumption growth rate; such a result seems to be supported by empirical evidence.  相似文献   
9.
This article proposes a new approach to testing for the hypothesisof a single priced risk factor driving the term structure ofinterest rates. The method does not rely on any parametric specificationof the state variable dynamics or the market price of risk.It simply exploits the constraint imposed by the no-arbitragecondition on instantaneous expected bond returns. In order toachieve our goal, we develop a Kolmogorov-Smirnov test and applyit to data on Treasury bills and bonds for both the United Statesand Spain. We find that the single risk factor hypothesis cannotbe rejected for either dataset.  相似文献   
10.
服务业集聚与产业结构优化关系探究   总被引:3,自引:0,他引:3  
随着全球化进程的不断加快,服务业集聚已经成为人们普遍关注的话题。产业集聚在获得规模效应的同时避免了垄断现象的产生,服务业集聚不但拥有这样的优势,而且还有自己独特的形成和发展特点。从产业结构的优化角度切入,借助区位商和专门化率等分析指标,以江苏省和上海市为例,对服务业集聚的形成进行理论和实证分析,提出产业结构的优化对于服务业集聚的形成和发展有着积极的作用。合理的产业结构能够为服务业集聚提供坚实的基础,各地区应该根据各自的产业特点积极的进行优化,催生服务业集聚,加快本地区经济的进一步发展。  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