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   3722篇
  免费   86篇
财政金融   874篇
工业经济   336篇
计划管理   600篇
经济学   647篇
综合类   64篇
运输经济   29篇
旅游经济   76篇
贸易经济   684篇
农业经济   190篇
经济概况   308篇
  2021年   19篇
  2020年   58篇
  2019年   85篇
  2018年   88篇
  2017年   79篇
  2016年   81篇
  2015年   38篇
  2014年   83篇
  2013年   472篇
  2012年   106篇
  2011年   120篇
  2010年   107篇
  2009年   109篇
  2008年   135篇
  2007年   115篇
  2006年   104篇
  2005年   93篇
  2004年   92篇
  2003年   89篇
  2002年   90篇
  2001年   79篇
  2000年   81篇
  1999年   64篇
  1998年   71篇
  1997年   59篇
  1996年   59篇
  1995年   40篇
  1994年   55篇
  1993年   44篇
  1992年   50篇
  1991年   55篇
  1990年   39篇
  1989年   56篇
  1988年   37篇
  1987年   44篇
  1986年   51篇
  1985年   81篇
  1984年   68篇
  1983年   57篇
  1982年   54篇
  1981年   45篇
  1980年   37篇
  1979年   40篇
  1978年   34篇
  1977年   43篇
  1976年   37篇
  1975年   37篇
  1974年   42篇
  1973年   24篇
  1971年   19篇
排序方式: 共有3808条查询结果,搜索用时 15 毫秒
71.
This paper examines the international trade of a variety of genetically modified (GM) food products over a 27-year period (1984–2011) with data from the United Nations using the tools of social network analysis. The results indicate that each of the different crops have a distinctive pattern of trade that has changed over time due to a number of different factors. Also, trade in agricultural commodities became more diversified over time, dominated less by the United States and other nations central in the trade networks and trade in the individual GM crops was stable over time. Countries maintained their trading partners for specific crops, despite the adoption of the genetically modified varieties. The economic implications of these results are discussed for specific countries.  相似文献   
72.
73.
74.
Product innovation management, by definition, requires that we become comfortable dealing with change. As this journal enters its eleventh year of publication, the editor-in-chief asked each member of the editorial board to reflect upon changes and opportunities that they see influencing our profession during the coming decade. In our first installment of these essays, George Day, Bela Gold and Thomas Kuczmarski discuss the value of managing ideas, embracing a longer-term view of development opportunities, and creating a senior executive position charged with developing such opportunities. Each of these short essays is designed to introduce new perspectives. It is not essential that you agree with the recommendations, but we hope that you are stimulated as you reflect on the issues they present.  相似文献   
75.
The growing internet concern (IC) over the crude oil market and related events influences market trading, thus creating further instability within the oil market itself. We propose a modeling framework for analyzing the effects of IC on the oil market and for predicting the price volatility of crude oil’s futures market. This novel approach decomposes the original time series into intrinsic modes at different time scales using bivariate empirical mode decomposition (BEMD). The relationship between the oil price volatility and IC at an individual frequency is investigated. By utilizing decomposed intrinsic modes as specified characteristics, we also construct extreme learning machine (ELM) models with variant forecasting schemes. The experimental results illustrate that ELM models that incorporate intrinsic modes and IC outperform the baseline ELM and other benchmarks at distinct horizons. Having the power to improve the accuracy of baseline models, internet searching is a practical way of quantifying investor attention, which can help to predict short-run price fluctuations in the oil market.  相似文献   
76.
77.
In 2015, the Federal Communications Commission (FCC) imposed common carriage regulation—so-called Title II requirements—on previously unregulated broadband Internet service providers. The regime shift was premised on the FCC’s findings that such rules had demonstrably yielded economic gains. This paper evaluates the FCC’s empirical arguments and finds them uncompelling. Adjustments for inflation or general economic trends eliminate the effects cited by the FCC. Moreover, contrary to the Commission’s assessment, mobile services and broadband markets have shown notable growth in response to deregulatory events that reduce Title II requirements.  相似文献   
78.
This study uses the Malmquist index with bias correction to analyze the performance of hotel chains from the UAE, Saudi Arabia and Oman. We show that Saudi Arabia hotel chains have the highest productivity growth, followed by the UAE and Omani hotel chains. A further decomposition of productivity indicates that a small number of hotel chains experienced an increase in revenues for lower occupancy rate, while most other hotel chains experienced an increase in occupancy rate for lower revenues. Related market discussions of the results are provided.  相似文献   
79.
On-line supervision exhibits in many respects properties complementary to those of established off-line safety tests. Thus, on-line methods are powerful tools for increasing the safety of chemical processes, especially in situations where unexpected hazards could occur. Known on-line supervising methods are described and their advantage and disadvantages are briefly discussed. The abilities of various on-line methods are demonstrated on a real case.  相似文献   
80.
There is little doubt that Brexit would have significant implications for UK agriculture, a sector with strong trade links to the EU and strong reliance on CAP income support. This article reports preliminary results from employing a Computable General Equilibrium Model, a Partial Equilibrium Model and Farm Level Models to explore selected trade and domestic policy scenarios post‐Brexit. These allow for the estimation of changes in producer prices, production and farm incomes against a baseline scenario of continued EU membership. Under a Free Trade Agreement with the EU, agricultural impacts are relatively modest. By contrast, unilateral removal of import tariffs has significant negative impacts on prices, production and incomes. Adoption of the EU's WTO tariff schedule for all imports favours net importers (e.g. dairy) and harms net exporters (e.g. sheep). Given the strong dependence of most UK farms on direct payments, their removal worsens negative impacts of new trade arrangements and offsets positive impacts. Impacts vary across different types and sizes of farm, but also regionally. However, the period of adjustment to new trade and domestic policy conditions may prove very challenging for a large number of farm businesses.  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