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   40748篇
  免费   695篇
  国内免费   3篇
财政金融   7066篇
工业经济   2498篇
计划管理   6729篇
经济学   9441篇
综合类   738篇
运输经济   212篇
旅游经济   406篇
贸易经济   8369篇
农业经济   1227篇
经济概况   4077篇
信息产业经济   47篇
邮电经济   636篇
  2023年   134篇
  2021年   186篇
  2020年   323篇
  2019年   524篇
  2018年   2756篇
  2017年   2544篇
  2016年   1725篇
  2015年   481篇
  2014年   723篇
  2013年   2713篇
  2012年   1314篇
  2011年   2778篇
  2010年   2541篇
  2009年   2317篇
  2008年   2224篇
  2007年   2476篇
  2006年   758篇
  2005年   969篇
  2004年   946篇
  2003年   1037篇
  2002年   706篇
  2001年   607篇
  2000年   545篇
  1999年   459篇
  1998年   522篇
  1997年   448篇
  1996年   458篇
  1995年   390篇
  1994年   389篇
  1993年   372篇
  1992年   380篇
  1991年   396篇
  1990年   363篇
  1989年   261篇
  1988年   281篇
  1987年   280篇
  1986年   282篇
  1985年   379篇
  1984年   371篇
  1983年   343篇
  1982年   300篇
  1981年   299篇
  1980年   296篇
  1979年   288篇
  1978年   239篇
  1977年   194篇
  1976年   193篇
  1975年   165篇
  1974年   156篇
  1973年   153篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
The Local Whittle Estimator of Long-Memory Stochastic Volatility   总被引:1,自引:0,他引:1  
We propose a new semiparametric estimator of the degree of persistencein volatility for long memory stochastic volatility (LMSV) models.The estimator uses the periodogram of the log squared returnsin a local Whittle criterion which explicitly accounts for thenoise term in the LMSV model. Finite-sample and asymptotic standarderrors for the estimator are provided. An extensive simulationstudy reveals that the local Whittle estimator is much lessbiased and that the finite-sample standard errors yield moreaccurate confidence intervals than the widely-used GPH estimator.The estimator is also found to be robust against possible leverageeffects. In an empirical analysis of the daily Deutsche Mark/USDollar exchange rate, the new estimator indicates stronger persistencein volatility than the GPH estimator, provided that a largenumber of frequencies is used.  相似文献   
62.
63.
64.
65.
66.
67.
Construction kits have played a significant part in nurturing the growth and development of the minds and manipulation-based skills of children (and adults) in formal and non-formal education settings. These kits have origins rooted in the representation of the built world and now have a diversity of form and function, including technical versions with moving parts. This article examines some of the historically based ideas that lie behind the role that kits may have in terms of physical modelling. The article traces the transformation of kits from simple bricks and blocks into more complicated pieces for space-filling and achieving the transfer of forces and motion. This transformation occurred during the Victorian era when the influence of the ideas of educationalists and, perhaps rather strangely, exponents of early aviation, played major roles in determining the diversity of forms of construction kit and modelled possibilities that are now to be seen in classrooms and homes. The article ends with a review of some of the lessons from the past and present that will need to be considered in relation to concrete modelling in schools for the future. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
68.
The open door policy of China’s economic reform since the 1980s has attracted heavy foreign direct investment (FDI) flows into China and especially to Guangdong (particularly the Pearl River Delta region, PRD) and induced significant economic growth during the past two decades. While there exist various classical theories of FDI in attempting to identify the determinants of FDI inflow and to explain the behavior of FDI flows, limited attention has been given from the perspective of agglomeration effects generated by a core-periphery (CP) relation.This paper intends to study the impacts of agglomerations on FDI inflows in the context of Krugman’s CP relation (1991) by investigating (1) the formation of a CP relation via gravity model analysis; (2) whether different types of industry FDI flows will respond differently in the CP-system, given agglomeration effects; and (3) whether FDI origin and firm scale matter in affecting FDI flows.A database consisting of a population frame of 37,742 firm-level manufacturing and services joint ventures investing in Guangdong in 1998 was used. Empirical results show that the agglomerations of the CP relation have affected FDI flow patterns. While both manufacturing and services FDI and sources of investment responded differently to the impacts, smaller firms were found more responsive to the CP-agglomeration settings regardless of FDI by industry type and by source. The significance and implications of the CP-system to further facilitate FDI in the region are discussed.  相似文献   
69.
The purpose of this article is to describe how households in Novgorod the Great, Russia, deal with food provision in everyday life. The study focuses on changes experienced in food provision and consumption in Russian society, in order to illustrate how households respond to the transformation towards a market economy. The study reflects women's perspective on food provision. Students from Novgorod the Great visited 105 households and asked the women in the household to answer a questionnaire. Results from the study show that in order to cope with changes in society related to economic reforms, Russian households had changed both their food consumption and food production patterns. There was no big difference between urban and rural households. Nearly all of the households were self‐sufficient in the provision of vegetables and potatoes. Many households had a ‘dacha’ (plot), where they produced most of what they needed. Among the changes experienced during recent years (i.e. during the end of the 1990s), a decade after perestroika was initiated, households mentioned the rise in food prices and the decrease of income. Households reported that they consumed less fruit and/or meat. Some households also mentioned that the quality of nourishment had decreased, thereby indicating lower general quality, lower nutrition value, or less healthy foodstuffs.  相似文献   
70.
This paper examines the influence of institutional differences on corporate risk management practices in the USA and the Netherlands. We compare results to surveys in each country using a strategy that corrects for differences over industry and size classes across the Dutch and US samples. We document several differences in the firms’ uses and attitudes towards derivatives and attempt to attribute them to the differences in the institutional environments between the USA and the Netherlands. We find that institutional differences appear to have an important impact on risk management practices and derivatives use across US and Dutch firms.  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