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   1551篇
  免费   61篇
财政金融   326篇
工业经济   74篇
计划管理   298篇
经济学   381篇
综合类   14篇
运输经济   15篇
旅游经济   38篇
贸易经济   242篇
农业经济   99篇
经济概况   123篇
邮电经济   2篇
  2023年   8篇
  2021年   12篇
  2020年   28篇
  2019年   23篇
  2018年   25篇
  2017年   48篇
  2016年   56篇
  2015年   34篇
  2014年   40篇
  2013年   209篇
  2012年   60篇
  2011年   52篇
  2010年   50篇
  2009年   63篇
  2008年   61篇
  2007年   53篇
  2006年   53篇
  2005年   49篇
  2004年   43篇
  2003年   51篇
  2002年   55篇
  2001年   38篇
  2000年   26篇
  1999年   41篇
  1998年   35篇
  1997年   32篇
  1996年   28篇
  1995年   21篇
  1994年   19篇
  1993年   16篇
  1992年   16篇
  1991年   12篇
  1990年   13篇
  1989年   13篇
  1988年   15篇
  1987年   17篇
  1986年   10篇
  1985年   21篇
  1984年   18篇
  1983年   20篇
  1982年   17篇
  1981年   14篇
  1980年   11篇
  1979年   16篇
  1978年   14篇
  1977年   12篇
  1976年   9篇
  1975年   5篇
  1974年   8篇
  1967年   4篇
排序方式: 共有1612条查询结果,搜索用时 31 毫秒
101.
This research aims at assessing the environmental impact of the poultry supply chain from cradle to grave using case study research and also life cycle assessment (LCA). While a limited number of generic poultry production LCA studies have been published, fewer yet assess the whole process of a specific organisation, none comparing the increased impact of further processing. Our results show that irrespectively of the impact assessment method utilised, the process of producing portions is considerably higher in total environmental impact due to the extra raw material required to produce the same mass into retail. Our research contributes to the growing number of LCA studies and could be used by practitioners for comparison against national and international averages. From a theoretical point of view, this research provides new insights into the relationship between vertically integrated supply chains and environmental performance which has not been examined in the past.  相似文献   
102.
This paper considers the implementation of a nonstationary, heterogeneous Markov model for the analysis of a binary dependent variable in a time series of independent cross sections. The model, previously considered by M offitt (1993), offers the opportunity to estimate entry and exit transition probabilities and to examine the effects of time-constant and time-varying covariates on the hazards. We show how ML estimates of the parameters can be obtained by Fisher's method-of-scoring and how to estimate both fixed and time-varying covariate effects. The model is exemplified with an analysis of the labor force participation decision of Dutch women using data from the Socio-economic Panel (SEP) study conducted in the Netherlands between 1986 and 1995. We treat the panel data as independent cross sections and compare the employment status sequences predicted by the model with the observed sequences in the panel. Some open problems concerning the application of the model are also discussed.  相似文献   
103.
104.
105.
A total of 289 studies of returns to agricultural R&D were compiled and these provide 1821 estimates of rates of return. After removing statistical outliers and incomplete observations, across the remaining 1128 observations the estimated annual rates of return averaged 65 per cent overall — 80 per cent for research only, 80 per cent for extension only, and 47 per cent for research and extension combined. These averages reveal little meaningful information from a large body of literature, which provides rate-of-return estimates that are often not directly comparable. This study was aimed at trying to account for the differences. Several features of the methods used by research evaluators matter, in particular assumptions about lag lengths and the nature of the research-induced supply shift.  相似文献   
106.
Two features common to many auctions are the use of reserve prices and the existence of secondary markets for the goods being sold. Even in simple symmetric settings, the combination of these features can preclude existence of an equilibrium in symmetric separating bidding strategies. With a reserve price sufficiently far below the maximum (endogenous) valuation, a symmetric equilibrium still exists, but with some types pooling at the reserve. The optimal reserve price depends not only on the joint distribution of bidders' information before and after the auction, but also on how surplus is divided in the secondary market. Journal of Economic Literature Classification Numbers: D44, C7, L1, D82  相似文献   
107.
With implications for navigation, safety, entertainment and vehicle maintenance as well as regulation and infrastructure investment in roads, telematics has the potential to transform driving more than any other innovation for decades. In the already well-established Asian telematics industry, revenue tends to come from extra charges at the time of vehicle-sale, with most subsequent services provided free. The US model has evolved differently, with much of the cost of telematics hardware and software subsidized in the initial vehicle sale price and revenue coming from services used. The decision to invest in telematics is therefore riskier in the US. This article first briefly summarizes the potential of telematics. It then analyzes the investment risks, particularly for automakers. It concludes with recommendations on how the US auto industry can minimize risk and make the most of the opportunities.  相似文献   
108.
Employment and child-care choices in Canada and the United States   总被引:1,自引:0,他引:1  
In this paper we examine employment and child-care choices of two-parent families with young children in the United States and Canada, using a pooled data set based on recent national surveys in each country. We find that the employment and child-care choices of Canadian families are similar to those of U.S. families. Estimates of a model of employment and child-care choices indicate significant effects of child-care subsidies, child-care prices, and wage rates on employment and child-care choices. However, none of these factors helps to explain the differences in employment and child-care choices between the two countries.
Ce mémoire examine le choix de l'emploi et du soin des enfants dans les familles où il y deux parents aux Etats-Unis et au Canada en utilisant des données d'études récentes dans les deux pays. Il appert que les choix des familles canadiennes sont semblables à ceux des familles américaines. Les calibrations d'un modèle de ces choix montrent les effets significatifs des subventions au soin des enfants, du prix des soins des enfants, et des taux de salaires sur ces choix. Cependant, aucun de ces facteurs n'explique les diffrences dans les patterns de choix entre les deux pays.  相似文献   
109.
We analyze periodic and seasonal cointegration models for bivariate quarterly observed time series in an empirical forecasting study. We include both single equation and multiple equation methods for those two classes of models. A VAR model in first differences, with and without cointegration restrictions, and a VAR model in annual differences are also included in the analysis, where they serve as benchmark models. Our empirical results indicate that the VAR model in first differences without cointegration is best if one-step ahead forecasts are considered. For longer forecast horizons however, the VAR model in annual differences is better. When comparing periodic versus seasonal cointegration models, we find that the seasonal cointegration models tend to yield better forecasts. Finally, there is no clear indication that multiple equations methods improve on single equation methods.  相似文献   
110.
This paper provides an alternative insight into Japan's current economic problems. We concentrate upon the role played by the economy's central actors, namely Japan's transnational corporations. Since the early 1980's, Japan's transnationals have become dominant players in the global economy, and now have a higher rate of physical investment in new, overseas greenfield sites than their competitors. This has had detrimental consequences for Japan's domestic economy, particularly for small firms who operate in keiretsu networks. This has led to concerns about the 'hollowing out' of Japan's domestic industry raising the possibility of long-term industrial decline and 'strategic failure'.  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