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   792篇
  免费   37篇
财政金融   107篇
工业经济   58篇
计划管理   149篇
经济学   236篇
综合类   1篇
运输经济   21篇
旅游经济   9篇
贸易经济   176篇
农业经济   25篇
经济概况   47篇
  2024年   2篇
  2023年   21篇
  2022年   8篇
  2021年   17篇
  2020年   29篇
  2019年   35篇
  2018年   64篇
  2017年   63篇
  2016年   49篇
  2015年   24篇
  2014年   37篇
  2013年   119篇
  2012年   45篇
  2011年   51篇
  2010年   37篇
  2009年   34篇
  2008年   36篇
  2007年   36篇
  2006年   20篇
  2005年   20篇
  2004年   12篇
  2003年   12篇
  2002年   3篇
  2001年   5篇
  2000年   7篇
  1999年   4篇
  1998年   6篇
  1997年   2篇
  1996年   3篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1992年   1篇
  1989年   1篇
  1988年   1篇
  1984年   1篇
  1983年   3篇
  1981年   4篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   6篇
  1975年   1篇
  1969年   1篇
排序方式: 共有829条查询结果,搜索用时 15 毫秒
81.
Whereas a few hundred generic drugs are essential for health care, the international and many national markets are flooded with tens of thousands of brand-name preparations. This numerical difference is because of the many imitative products, drug combinations, brandname duplications, and drugs with low therapeutic value and/or unacceptable adverse effects. Since independence Mozambique has reduced the number of registered products, including those for retail pharmacy sale, from some 26,000 to about 1200. An effective national formulary has been introduced for health service use and now contains only 343 distinct therapeutic substances. The formulary uses only international non-proprietary names, and has been used to rationalize state pharmaceutical procurement with cost savings and to improve drug information and use.  相似文献   
82.
In this paper we estimate the DEA technical efficiency for 4796 Brazilian municipalities, by applying a recently proposed “Jackstrap” method, which combines Bootstrap and Jackknife resampling techniques, to reduce the effect of outliers and possible errors in the data set. We perform calculations to identify and eliminate high leverage municipalities, using different variants of Data Envelopment Analysis (DEA), as well as Free Disposal Hull (FDH). Corroborating previous results, efficiency results for the Brazilian municipalities show a clear relationship between the size of the municipality and its efficiency scores. Indeed, under both DEA variants, smaller cities tend to be less efficient than larger ones hence indicating that the quality of the frontier adjustment improves significantly as the size of the municipality increases. We present arguments that may explain to some extent these findings, such as economies of scale and the excess spending due to revenue from royalties. However, such effects require further, more careful examination.  相似文献   
83.
Technological innovations have been investigated by means of substitution and diffusion as well as evolution models, each of them dealing with different aspects of the innovation problem. In this paper we follow the well known research traditions on self-organisation models of complex systems. For the first time in the literature we show the existence of a specific niche effect, which may occur in the first stage of establishment of a new technology. Using a stochastic Master equation approach, we obtain analytical expressions for the survival probabilities of a new technology in smaller or larger ensembles. As a main result we demonstrate how a hyperselection situation might be removed in a stochastic picture and thresholds against the prevailing of a new technology in a step-by-step process can be overcome.  相似文献   
84.
This article is geared toward shedding some more light on what may be the next space race and its contours.Space flight is undoubtedly a human achievement of the second half of the 20th century, and probably the most audacious one of the past century. The space race started suddenly in the 1950s and has grown explosively during the following two decades, but decreased steadily after the 1970s. After the 1990s, however, we have seen a shy rebirth of space-related activities, when many other actors (states) entered the stage, adding up to the agonizing role of the two-actor piece that we have witnessed during the so-called Cold War.The opening years of the 21st century provided a more complex narrative for space exploration. At the start of the new millennium a new technosphere [1] emerged, dominated by what is used to be called as the Information and Communications Technologies (ICT), with the Internet playing the leading role among the bandwagon of technological novelties that appeared during the twilight of space activities. In despite of the fact that artificial satellites represent the very backbone of the global communications system, space activities seem to play a secondary role amidst the apparently accelerated rate of change concerning the technological systems of the present technosphere. But, as it is demonstrated in this paper, things are changing, and very probably a renewed space race will unfold in the coming decades.A question may be placed: what happened? Why the Earth stood still with regard to the race toward the cosmos? Answer: futurists, even prestigious ones like Herman Kahn and Arthur Clarke, did not consider the existence of socioeconomic long waves (Kondratieff waves, or K-waves for short) with their two decades long economic downturn, which has contributed to the deceleration of space-related activities.Analyzing the worldwide evolving scenario of space-related activities during the last eighty years under the framework of the succeeding K-waves and applying some technological forecasting tools, namely the logistic analysis, technological surveillance and intensive data mining, scrutinizing more than 7500 events occurred in the period 1930–2010 related with space activities, it is demonstrated that the space race like the one that we have witnessed until now is a natural growth process that has saturated at the dawn of this century. The same analysis demonstrates that a new growth process in this field might be nowadays under way with contours very different from that imagined by futurists and science fiction writers sixty years ago. Also the main trends in the usage of launching vehicles and satellites are framed and discussed in this paper.  相似文献   
85.
Using the British Household Panel Survey, this paper finds that inheritance has a concave effect on the hours worked by male entrepreneurs. Receiving an inheritance increases the labor supply of unemployed male entrepreneurs; however this effect becomes smaller for higher inheritances.  相似文献   
86.
ABSTRACT

In the construction of input–output models from supply-use tables, technology assumptions disambiguate how an industry uses inputs in the production recipe of multiple outputs. This paper uses Bayes' theorem to select technology assumptions, taking into account empirical observations. The paper presents a formulation to explore hybrids between product and industry technology assumptions in product-by-product tables. We then present Markov chain Monte-Carlo techniques to implement the Bayesian method for selecting technology assumptions. We apply the method in a case study using Eurostat supply-use tables of 2004 and 2005, exhibiting a volume of secondary products of less than 13%, and 59 products and industries per country. The results show that the choice of technology is not important, given that there is no strong evidence in favour of any of them.  相似文献   
87.
This study tests for macro‐hysteresis in Brazilian exports of manufactured products using a panel model with threshold parameters according to Hansen. To test hysteresis, the threshold variables are built based on studies by Parslei and Wei, and Penkova. There is evidence of asymmetrical responses, with more pronounced increases in the price elasticity of demand during periods of high depreciation of the exchange rate compared with periods of more pronounced currency appreciation. We also estimate the relative price intervals that correspond to the inaction band.  相似文献   
88.
In this paper we present a model to evaluate transient industry effects, that is, the impact of business cycles on the industry. While the importance of the economic cycle for industry and firm performance is widely recognized, we do not know much about how much the business cycle influences industry activity. The aim of this paper is to present a method that helps to understand the relationship between the business cycle and an industry's level of activity. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
89.
Propensity to firm creation: empirical research using structural equations   总被引:2,自引:0,他引:2  
The identification of the entrepreneurs’ characteristics and the knowledge of the entrepreneurial profile of university students have been assuming a growing importance in the development of educational programs directed towards the entrepreneurship and start-up processes. This study aims to identify the factors that most contribute for the intention to start up a business. The research also tries to identify the profile of a potential entrepreneur student concerning several characteristics: personal attributes, family, demographic variables and motivations. Research findings include the idea that entrepreneurship education is the most relevant factor in what concerns the propensity to business creation. On the other side, personal characteristics have an important role in shaping motivation to start-up a business and perceived hurdles have a negative impact in the intention to start-up. The results may be relevant when developing an adequate educational program directed to the entrepreneurship education and start-up processes.  相似文献   
90.
In the knowledge society, universities have assumed new missions and relations in order to contribute to economic and social development, while preserving their own sustainability. This article aims to explore scientific literature on innovation and entrepreneurship in the academic setting, describing how the field is organized, main terms and definitions, theoretical frameworks, and empirical models, in order to direct future research. A systematic literature review was conducted, in which articles indexed at Web of Science were initially submitted to a bibliometric analysis. Then, the content of a set of articles best fitting the objectives of the study was analyzed. Bibliometric analysis shows an increasing literature, with publications over more than 40 years. There are studies from many disciplines, with those in business and economics prevailing, mainly related to management and originating from the USA and Europe. Content analysis shows a fragmented literature, with definitions not showing a clear relationship between innovation and entrepreneurship, or their use within universities in coherence with their traditional definitions. Both theoretical frameworks and empirical models are very heterogeneous, but four groups of studies were identified based on their theoretical frameworks, and also based on their empirical models. With only a few exceptions, empirical models do not share many components and variables, and there are no clear boundaries between the different models. Despite the increasing literature, it is still fragmented and undertheorized, requiring more systematic and holistic studies, considering both the economic and the social aspects of innovation and entrepreneurship within universities.  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