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   2540篇
  免费   119篇
  国内免费   38篇
财政金融   231篇
工业经济   154篇
计划管理   819篇
经济学   477篇
综合类   300篇
运输经济   8篇
旅游经济   19篇
贸易经济   333篇
农业经济   74篇
经济概况   282篇
  2024年   1篇
  2023年   30篇
  2022年   22篇
  2021年   54篇
  2020年   53篇
  2019年   51篇
  2018年   45篇
  2017年   73篇
  2016年   71篇
  2015年   87篇
  2014年   197篇
  2013年   228篇
  2012年   242篇
  2011年   293篇
  2010年   236篇
  2009年   181篇
  2008年   190篇
  2007年   166篇
  2006年   118篇
  2005年   84篇
  2004年   60篇
  2003年   42篇
  2002年   29篇
  2001年   29篇
  2000年   20篇
  1999年   15篇
  1998年   8篇
  1997年   12篇
  1996年   11篇
  1995年   3篇
  1994年   3篇
  1993年   7篇
  1992年   3篇
  1991年   7篇
  1990年   5篇
  1989年   5篇
  1988年   3篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1984年   5篇
  1983年   1篇
  1982年   2篇
排序方式: 共有2697条查询结果,搜索用时 15 毫秒
1.
Programs to improve water quality do not improve all water bodies equally. Evaluation of the benefits of such programs must account for where improvements occur and the relative magnitude of improvements that occur in different places. This study uses a choice experiment survey to explore how the value to a household of a surface water quality improvement varies as a function of (i) the distance between the household and the affected streams and rivers, (ii) the degree to which the quality of the water has been improved, (iii) how many stream and river miles have been improved, and (iv) the sizes of the affected streams and rivers. Results show evidence that value declines with distance in an approximately linear way, weak evidence that large rivers are worth more than small rivers, and no evidence that willingness-to-pay is nonlinear in either the degree of water quality improvement or the number of stream miles improved. These results indicate that it may be defensible in applied work to value small, spatially-explicit water quality improvement projects independently and then sum over projects.  相似文献   
2.
人工收集和整理2012—2018年在中国市场上映的首轮院线电影信息数据,构建电影需求的嵌套logit回归模型,以新冠肺炎疫情为准自然实验,来量化突发公共事件对电影行业复产复工的影响。结果显示:第一,关于上映时间选择,在恢复营业后,如果所有因为疫情尚未上映的电影选择顺延上映能有效避免过度竞争的局面。第二,关于上映节奏控制,控制好未定档电影的上映节奏,保持适当的竞争能促进经济效益提升。其中,从11月份开始以每周两部的频率上映未定档电影的经济效益最佳。第三,关于上映方式选择,与线下播放相比,疫情期间选择线上播放能及时收回成本并有利于经济收益最大化的实现。研究结论为电影行业制定复产复工策略提供依据,为未来应对突发公共卫生事件提供参考。  相似文献   
3.
The Prebisch–Singer hypothesis in economics asserts that over time the relative price of primary goods relative to manufactured goods should experience a downward trend. To test the hypothesis, we must first establish the unit root properties of the relative price term and then regress the stationary series on a trend term. We use the quantile unit root test which allows for both smooth unknown numbers and the form of breaks in the trend function through a Fourier function to show that the relative price of 23 out of 24 primary goods is stationary. However, the Prebisch–Singer hypothesis is supported only in half of the primary commodities.  相似文献   
4.
We revisit hysteresis effect in the unemployment rate of each of the 52 states of the United States using nonlinear quantile unit root test over the period 1976M1–2016M7. Our results indicate that unemployment rate of the U.S. economy as a whole displays hysteresis effect over recessionary periods. Nineteen out of 52 states display hysteresis behaviour over the period 1976–2016. For the remaining 33 states, we find four types of behaviours. Some states display stationarity behaviour almost in all quantiles. Some display hysteresis over recessionary periods and in contrast some display hysteresis over expansion period.  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.
李春涛  薛原  惠丽丽 《金融研究》2018,457(7):124-142
本文利用中国A股上市公司2006-2015年的数据,研究社保基金持股对上市公司盈余质量的影响。我们用上市公司财务重述作为测度盈余质量的指标,发现社保基金持股能够显著降低企业发布财务重述的概率,这表明社保基金对上市公司盈余质量的提高具有促进作用。并且,社保基金的这一治理作用在国有企业、内部治理水平较差以及市场化程度较低地区的上市公司中更加显著。通过双重差分模型和安慰剂检验等方法弱化了内生性问题之后,以上结论依然成立,说明社保基金持股和盈余质量提升之间存在因果关系,我们称之为社保基金的公司治理作用。进一步研究发现,社保基金可以通过抑制控股股东资金占用、增加机构调研次数等途径提升被持股公司的盈余质量。本文有助于认识和评估社保基金持股对于上市公司的监督与治理作用。  相似文献   
7.
This letter shows that the ‘Whatever it takes’ speech by ECB President Draghi on 26 July 2012 and the ensuing installation of the Outright Monetary Transactions’ framework are associated with a reduction in the domestic and cross-border effect of Eurozone news on absolute yield changes in Eurozone sovereign debt. These results are consistent with the popular view that these actions helped to avoid a collapse of the Eurozone.  相似文献   
8.
In this paper, we consider portmanteau tests for testing the adequacy of multiplicative seasonal autoregressive moving‐average models under the assumption that the errors are uncorrelated but not necessarily independent. We relax the standard independence assumption on the error terms in order to extend the range of applications of the seasonal autoregressive moving‐average models. We study the asymptotic distributions of residual and normalized residual empirical autocovariances and autocorrelations under weak assumptions on noise. We establish the asymptotic behavior of the proposed statistics. A set of Monte Carlo experiments and an application to monthly mean total sunspot number are presented.  相似文献   
9.
This study investigates price relationships between organic and conventional carrots, tomatoes, and lettuce in the U.S. utilizing Nielsen scanner data from 2006–2015. We employ a threshold vector error correction model (TVECM), threshold vector autoregressive model (TVAR), and threshold cointegration test to test whether market integration exists between organic and conventional vegetables as well as the existence of asymmetric price transmission. The results find positive long-run relationships between organic and conventional prices of carrots and tomatoes and show the existence of asymmetric price transmission in price pairs of lettuce and tomatoes. Our findings suggest that the price relationship between organic and conventional vegetables varies by characteristics, such as shelf life, volatility in the price premium, and substitutability.  相似文献   
10.
提出一种针对复杂机电液系统的虚拟仿真试验方法,分别在ADAMS、AMESim、MATLAB/Simulink软件中建立机械子系统、液压子系统和控制子系统模型,并基于软件间接口技术,建立动态数据共享通道,实现系统的全面仿真分析,为系统设计与优化、控制策略选择等提供依据.该方法对于复杂机电液系统仿真分析具有普遍适用性,对缩短产品开发周期、降低产品研发成本、减轻仿真工作复杂性具有重要意义.  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