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   10565篇
  免费   295篇
财政金融   2020篇
工业经济   1012篇
计划管理   1757篇
经济学   2365篇
综合类   134篇
运输经济   84篇
旅游经济   208篇
贸易经济   1874篇
农业经济   565篇
经济概况   837篇
信息产业经济   2篇
邮电经济   2篇
  2023年   52篇
  2021年   50篇
  2020年   125篇
  2019年   162篇
  2018年   175篇
  2017年   208篇
  2016年   212篇
  2015年   141篇
  2014年   213篇
  2013年   1364篇
  2012年   283篇
  2011年   387篇
  2010年   275篇
  2009年   337篇
  2008年   326篇
  2007年   327篇
  2006年   331篇
  2005年   304篇
  2004年   275篇
  2003年   303篇
  2002年   301篇
  2001年   265篇
  2000年   226篇
  1999年   230篇
  1998年   238篇
  1997年   226篇
  1996年   201篇
  1995年   165篇
  1994年   157篇
  1993年   178篇
  1992年   161篇
  1991年   160篇
  1990年   131篇
  1989年   114篇
  1988年   117篇
  1987年   102篇
  1986年   119篇
  1985年   184篇
  1984年   199篇
  1983年   157篇
  1982年   158篇
  1981年   148篇
  1980年   158篇
  1979年   153篇
  1978年   105篇
  1977年   105篇
  1976年   98篇
  1975年   73篇
  1974年   97篇
  1973年   53篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
A systems model was estimated to determine the effects of declining U.S. retail beef demand on farm-level beef prices and production. Retail beef demand declined by nearly 66% from 1976 to 1999. Results indicate autonomous shifts in retail demand significantly impacted farm-level demands and production. Based on equilibrium multipliers, the 1976–99 reduction in beef demand decreased real slaughter cattle prices and production by 32.1% and 11.2%, respectively. Real feeder cattle prices and production decreased by 8.0% and 22.6%, respectively. Combining the decreases in farm prices and production, slaughter and feeder cattle producers experienced a real revenue reduction of $13.3 billion (61%) due to the long-term decline in demand.  相似文献   
102.
Dynamic futures‐hedging ratios are estimated across seven markets using generalized models of the variance/covariance structure. The hedging performances of the resultant dynamic strategies are then compared with static and naïve strategies, both in‐ and out‐of‐sample. Bayesian‐adjusted hedge ratios also are employed as error purgers. The empirical results indicate that the generalized dynamic models are well specified and that their use in determining optimal hedge ratios can lead to improvements in hedging performance as measured by the volatilities of the returns on the optimally hedged position. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:241–260, 2003  相似文献   
103.
In this article, we examine the impact of 21 different types of scheduled macroeconomic news announcements on S&P 100 stock‐index option volume and implied volatility. We find that there is a 2‐h delay after the announcement before volume increases. However, there is an immediate increase in volatility, which slowly dissipates over several hours. Further analysis shows that most of the high volume and volatility after announcements come from the announcements that are considered bad news. That is, bad news creates high volatility and high volume, whereas good news elicits lower volume and is not associated with higher volatility. These results are not consistent with the predictions of any one model. We also find that the announcements that cause the largest reaction in the equity option market are Consumer Credit, Consumer Spending, Factory Inventories, NAPM, and Non‐Farm Payrolls. Six other announcements elicit a mild response. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:315–345, 2003  相似文献   
104.
The primary purpose of this research was to investigate the effect of investment in information technology in a supply chain. The results of that investigation are presented by focusing on an empirically tested supply chain relationship model containing both behavioral and operational constructs. The four behavioral constructs represented in the model are relationship trust, relationship commitment, relationship dependence, and long‐term relationship orientation. The four operational constructs represented in the model are retailer investment in interorganizational information technology, perceived supplier investment in interorganizational information technology, logistics efficiency, and logistics effectiveness. Among other findings, the results of the investigation found that perceived supplier investment in interorganizational information technology has a significant and positive effect on logistics efficiency.  相似文献   
105.
Close relationships between and among supply chain members are becoming more prevalent. However, there is lack of agreement in the literature and in practice concerning the characteristics of different interorganizational relationships. The resultant confusion is an obstacle to the progression of research and could cause problems among firms in a supply chain. Based on previous research and an exploratory study conducted with company executives responsible for supply chain management activities, this article seeks to introduce the concept of relationship magnitude (i.e., the extent or degree of closeness or strength of the relationship) and differentiate it from relationship type (i.e., classes of relationships that share common traits). Implications for managers and opportunities for future research are provided.  相似文献   
106.
This paper combines insights from the literature on the economics of organisation with traditional models of market structure to construct a theory of equilibrium firm size heterogeneity under the assumption of a homogenous product industry. It is possible that configurations consisting entirely of small firms (run by entrepreneurs with limited attention) and with larger firms (using managerial techniques to substitute away these limits to allow increasing returns technologies to become profitable) can arise in equilibrium. However, there also exist equilibrium configurations with the co-existence of large and small firms. The efficiency properties of these respective equilibria are discussed. Finally, the implications of an expanding market size are considered.  相似文献   
107.
A model to simulate the costs and returns of an individual dairy cow over 14 years under various assumptions of genetic potential, health status and management was developed especially to evaluate the effects of diseases that reduce production and reproduction efficiency and to evaluate alternative management interventions. Data were collected from the Food Animal Health Resource Management System (FAHRMX), Today's Electronic Planning (TELPLAN), Today's Electric Farm Accounting (TELFARM) databases and secondary sources at Michigan State University. A case study of cystic ovaries was analysed using the model. The results showed that it is more economical to treat cystic ovaries than not to treat, and treatment with Gonadotropin Releasing Hormone (GNRH) was superior to Human Chrionic Gonadotropin (HCG). Four to five lactations were the optimum for keeping a dairy cow to replacement and it was estimated that there is a loss of US$0.45 per day of extended calving interval (days open beyond the optimal 70 days).  相似文献   
108.
109.
110.
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