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   49076篇
  免费   931篇
  国内免费   1篇
财政金融   8375篇
工业经济   3104篇
计划管理   8197篇
经济学   11390篇
综合类   817篇
运输经济   225篇
旅游经济   479篇
贸易经济   9898篇
农业经济   1526篇
经济概况   5271篇
信息产业经济   47篇
邮电经济   679篇
  2023年   166篇
  2021年   218篇
  2020年   411篇
  2019年   627篇
  2018年   2931篇
  2017年   2767篇
  2016年   1971篇
  2015年   624篇
  2014年   931篇
  2013年   3508篇
  2012年   1531篇
  2011年   2977篇
  2010年   2728篇
  2009年   2524篇
  2008年   2457篇
  2007年   2666篇
  2006年   935篇
  2005年   1114篇
  2004年   1107篇
  2003年   1251篇
  2002年   825篇
  2001年   763篇
  2000年   720篇
  1999年   582篇
  1998年   661篇
  1997年   616篇
  1996年   599篇
  1995年   547篇
  1994年   527篇
  1993年   522篇
  1992年   560篇
  1991年   561篇
  1990年   486篇
  1989年   396篇
  1988年   376篇
  1987年   382篇
  1986年   381篇
  1985年   544篇
  1984年   510篇
  1983年   499篇
  1982年   419篇
  1981年   453篇
  1980年   417篇
  1979年   423篇
  1978年   350篇
  1977年   291篇
  1976年   307篇
  1975年   266篇
  1974年   243篇
  1973年   227篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
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   
73.
B.   《Technovation》2003,23(12):929-937
This research investigates the degree of emphasis placed by the Australian manufacturing industry on Research and Development (R&D) strategy as well as on other organisational strategies such as marketing, HRs (HR), technology, and operations at the functional level. The research extends further to investigate whether the emphasis on R&D strategy differs with contextual factors such as firm size, firm’s generic strategy, type of market, firm’s life cycle stage, etc. A mail survey was carried out to collect information from manufacturing firms across Australia. This was followed by an on-site interview of some of the senior managers of manufacturing firms from three Australian states: South Australia, Victoria and New South Wales.The study found that although the emphasis on R&D strategy has received a high priority in the past few years, it has not been as effective as the operations strategy and the technology strategy. The operations strategy has been accorded the highest importance in the past few years and this will continue in the future. The study also indicated that firms, which adopt a differentiation generic strategy, put more emphasis on R&D than the firms, which adopt cost leadership and focus generic strategies. The results did not indicate any evidence of a relationship between firm size and the R&D strategy although large firms are found to put more emphasis on operations and marketing strategies. Relatively higher emphasis was placed on the R&D strategy by businesses: at the growth stage; involved in the manufacture of consumer goods as opposed to industrial goods; involved in exports with a higher sales growth in export markets; and having a higher growth rate relative to their industry.  相似文献   
74.
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   
75.
Recent advances in asset pricing—the reduced-form approach to pricing risky debt and derivatives—are used to quantitatively evaluate several proposals for mandatory bank issue of subordinated debt. We find that credit spreads on both fixed- and floating-rate subordinated debt provide relatively clean signals of bank risk and are not unduly influenced by nonrisk factors. Fixed-rate debt with a put is unacceptable, but making the putable debt floating resolves most problems. Our approach also helps to clarify several different notions of “bank risk.”  相似文献   
76.
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   
77.
78.
In this article the impact of technology education, as a new learning area (subject) in the curriculum, on in-service teacher education in South Africa is described in order to ascertain the extent of the impact. The research on which this article is based draws on a variety of experiences and observations in the field at grassroots level (in particular an outreach project in rural communities). The envisaged impact of technology education on South African schools, communities, teacher educators and teachers, the range of in-service teacher education that is required, and the impacts in urban and rural areas are discussed. Finally a number of concluding remarks are made about the extent of the impact of the inclusion of technology education in the new National Curriculum Statement and whether the situation has changed since the implementation of a pilot technology education project in 1998. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
79.
In rational, efficiently functioning and complete markets, returns on derivative and underlying securities should be perfectly contemporaneously correlated. Due to market imperfections, one of these markets may reflect information faster. The use of high-frequency data and the choice for a small unit time interval to measure these lead-lag relations comes at the cost of some or many missing observations, causing traditional estimators to either under- or overestimate covariances and correlations. We use a new estimator to estimate lead-lag relationships between the cash AEX index, options and futures. We find that futures returns lead both options and cash index returns by approximately 10 minutes. The relationship between options and the cash market is not completely unidirectional.  相似文献   
80.
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