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   50090篇
  免费   1193篇
  国内免费   4篇
财政金融   9933篇
工业经济   3719篇
计划管理   8074篇
经济学   11129篇
综合类   668篇
运输经济   315篇
旅游经济   832篇
贸易经济   7884篇
农业经济   2435篇
经济概况   6144篇
信息产业经济   1篇
邮电经济   153篇
  2021年   270篇
  2020年   533篇
  2019年   799篇
  2018年   929篇
  2017年   1016篇
  2016年   1020篇
  2015年   634篇
  2014年   1054篇
  2013年   5018篇
  2012年   1429篇
  2011年   1540篇
  2010年   1334篇
  2009年   1529篇
  2008年   1419篇
  2007年   1315篇
  2006年   1189篇
  2005年   1034篇
  2004年   1026篇
  2003年   1031篇
  2002年   1024篇
  2001年   1001篇
  2000年   1052篇
  1999年   958篇
  1998年   902篇
  1997年   939篇
  1996年   895篇
  1995年   850篇
  1994年   823篇
  1993年   847篇
  1992年   898篇
  1991年   881篇
  1990年   728篇
  1989年   654篇
  1988年   642篇
  1987年   626篇
  1986年   675篇
  1985年   991篇
  1984年   909篇
  1983年   855篇
  1982年   794篇
  1981年   824篇
  1980年   800篇
  1979年   734篇
  1978年   642篇
  1977年   569篇
  1976年   493篇
  1975年   523篇
  1974年   423篇
  1973年   410篇
  1972年   310篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
The Review of Austrian Economics - A key insight in Hayek’s thought is the importance of so-called “local knowledge” in economic activity. In The Fatal Conceit, he states that...  相似文献   
4.
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   
5.
Growing urbanisation in South Africa is reflected in burgeoning Working class and informal township settlements on the fringes of its major towns and cities. Paired with this is an increasing reliance on cash as the primary means of economic transaction, which has in turn stimulated the growth of micro-enterprise business activities within the township context. This article discusses the findings of an eight-township small-area census which occurred between 2010 and 2013 in Cape Town, Johannesburg, Ekurhuleni and Durban townships representing 250 000 residents. The researchers were able to establish the scope and scale of informal food and drink retailing in these localities. Of the 10 049 micro-enterprises located in the study, some 3966 (or 39% of the total) trade in food. These include enterprises in primary production, fresh produce retailing, grocery retailing from house and spaza shops, and informal foodservice enterprises. Food is the basis for much township informal business and plays an important role in making food increasingly affordable and locally accessible, and in creating cash employment. The article builds on the knowledge base of the township informal economy role in bolstering food security needs for the marginalised.  相似文献   
6.
Without guaranteed compensation, granted by the German Renewable Energy Sources Act (Erneuerbare Energien Gesetz/EEG), biogas plants compete with all other plant types on the market for electrical energy. However, exchange-based electricity products do not currently permit an economically viable operation of biogas plants owing to their cost situation.  相似文献   
7.
8.
Objective: This study was to determine if calcium fortification yields a higher price per serving in grocery store products. Researchers compared store brand to national brand grocery products in relation to cost in order to examine if calcium values were similar between store brand and national brand products. Methods: A total of 112 store brand and 211 national brand grocery products were collected from three low (national chain store), middle and high priced (Virginia and North Carolina regional store) grocery venues. Products were compared using price and calcium percentage per serving. ANOVA was used to determine between store brand and national brand for price per serving and calcium content, and between grocery venues. Results: National brand fortified products had a significantly lower mean price per serving when compared to national brand non-fortified products (p = 0.0002). There was no statistical difference between store brand fortified and non-fortified products (p = 0.9256). Low priced store brand products had the lowest mean price per serving ($0.34 ±0.24). Conclusions: This study found store brand products have similar calcium content as national brand products. Product cost was lower at low priced store compared to middle and high priced stores.  相似文献   
9.
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