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   139250篇
  免费   4124篇
  国内免费   1篇
财政金融   26003篇
工业经济   11680篇
计划管理   22337篇
经济学   30215篇
综合类   1482篇
运输经济   1049篇
旅游经济   2569篇
贸易经济   24308篇
农业经济   6198篇
经济概况   17232篇
信息产业经济   7篇
邮电经济   295篇
  2021年   922篇
  2020年   1774篇
  2019年   2538篇
  2018年   2658篇
  2017年   2929篇
  2016年   3018篇
  2015年   2245篇
  2014年   3579篇
  2013年   16067篇
  2012年   4397篇
  2011年   4318篇
  2010年   3896篇
  2009年   4496篇
  2008年   4007篇
  2007年   3331篇
  2006年   3629篇
  2005年   3605篇
  2004年   3134篇
  2003年   2922篇
  2002年   2890篇
  2001年   2646篇
  2000年   2561篇
  1999年   2464篇
  1998年   2291篇
  1997年   2341篇
  1996年   2194篇
  1995年   1988篇
  1994年   2016篇
  1993年   1987篇
  1992年   2042篇
  1991年   1925篇
  1990年   1822篇
  1989年   1679篇
  1988年   1614篇
  1987年   1610篇
  1986年   1691篇
  1985年   2451篇
  1984年   2340篇
  1983年   2115篇
  1982年   1976篇
  1981年   1925篇
  1980年   1882篇
  1979年   1812篇
  1978年   1631篇
  1977年   1631篇
  1976年   1388篇
  1975年   1270篇
  1974年   1189篇
  1973年   1186篇
  1972年   900篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
We collected 469 frontal face images of Ukrainian cabinet ministers who were in office in 2000–2020. For each image, the minister's body mass index was estimated using a computer vision algorithm. The time series of median estimated body mass index of cabinet ministers co-moves over time with two existing measures of corruption – World Bank worldwide governance indicator Control of Corruption, and the discrepancy between the quantity of luxury wristwatches exported from Switzerland to Ukraine (reported by Swiss statistics) and the corresponding quantity imported by Ukraine from Switzerland (reported by Ukrainian statistics).  相似文献   
2.
Portuguese Economic Journal - A set of RLS-type models with ARMA and ARFIMA dynamics is estimated and compared in a forecasting exercise with ARFIMA, GARCH and FIGARCH models. It is an extension of...  相似文献   
3.
4.
Prior research has shown that the well-being of employees engaged in intensive work can vary with the discretion their jobs afford regarding how and when to carry out the work. This article explores a different avenue. It argues that well-being also varies with employees’ individual motives for working intensively. The article introduces self-determination theory to the domain of work intensity and focuses on two hypotheses. The first is whether intensive work driven by explicit or implicit incentives is more positively associated with an employee's job satisfaction than intensive work driven by job demands. The second is whether intensive work driven by intrinsic motives is more positively associated with job satisfaction than that driven by explicit or implicit incentives. In both these cases, the article also examines whether equivalent effects exist on (reduced) quit intentions. Original data from a major Greek grocery chain provide corroborative evidence that is robust to a rich set of covariates, including increasingly demanding adjustments for job discretion. The findings contribute to a more complete understanding of why differences in well-being exist among employees performing intensive work, with implications for workers and employers.  相似文献   
5.
We investigate the impact of housing wealth, credit availability and financial distress on college enrolment decisions. We find that housing wealth is negatively related to enrolment in public schools and positively related to enrolment in private schools. This evidence suggests that, on average, students substituted away from private schools towards public institutions during the recent financial crisis.  相似文献   
6.
We use a unique firm-level data set including 9000 companies from 26 European Union countries covering four different sectors to take a close look at the relationship between online exports and productivity. The online exporter productivity premium is estimated using different techniques (ordinary least squares, quantile regressions and robust estimation). Results consistently indicate that the estimated online exporter productivity premium is statistically different from zero, positive and significant from an economic point of view. European online exporters, according to these results, are approximately 2% more productive than non-online exporters. Productivity differences between firms could be related to variables that are not included in the empirical model. More research would be needed to address this issue in the future.  相似文献   
7.
8.
This paper presents an approach to assessing the efficacy of public spending on research and development in state programs. At present, there is a need to develop a unified approach to the analysis and evaluation of the efficacy of such spending from the perspective of participants in state programs (federal executive bodies). The proposed approach does not allow evaluating the efficacy of public spending on the development of research areas assigned to the authors.  相似文献   
9.
The main objective of this paper it to model the dynamic relationship between global averaged measures of Total Radiative Forcing (RTF) and surface temperature, measured by the Global Temperature Anomaly (GTA), and then use this model to forecast the GTA. The analysis utilizes the Data-Based Mechanistic (DBM) approach to the modelling and forecasting where, in this application, the unobserved component model includes a novel hybrid Box-Jenkins stochastic model in which the relationship between RTF and GTA is based on a continuous time transfer function (differential equation) model. This model then provides the basis for short term, inter-annual to decadal, forecasting of the GTA, using a transfer function form of the Kalman Filter, which produces a good prediction of the ‘pause’ or ‘levelling’ in the temperature rise over the period 2000 to 2011. This derives in part from the effects of a quasi-periodic component that is modelled and forecast by a Dynamic Harmonic Regression (DHR) relationship and is shown to be correlated with the Atlantic Multidecadal Oscillation (AMO) index.  相似文献   
10.
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