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   3502篇
  免费   183篇
  国内免费   47篇
财政金融   118篇
工业经济   454篇
计划管理   921篇
经济学   834篇
综合类   315篇
运输经济   27篇
旅游经济   40篇
贸易经济   309篇
农业经济   236篇
经济概况   478篇
  2024年   17篇
  2023年   59篇
  2022年   73篇
  2021年   117篇
  2020年   111篇
  2019年   72篇
  2018年   61篇
  2017年   99篇
  2016年   118篇
  2015年   152篇
  2014年   336篇
  2013年   265篇
  2012年   413篇
  2011年   508篇
  2010年   357篇
  2009年   247篇
  2008年   197篇
  2007年   145篇
  2006年   117篇
  2005年   68篇
  2004年   38篇
  2003年   35篇
  2002年   17篇
  2001年   18篇
  2000年   18篇
  1999年   18篇
  1998年   3篇
  1997年   13篇
  1996年   6篇
  1995年   6篇
  1994年   3篇
  1993年   3篇
  1992年   6篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1987年   1篇
  1985年   1篇
  1984年   5篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
排序方式: 共有3732条查询结果,搜索用时 31 毫秒
1.
The panel data analysis points to economic and social factors contributing to NOx, PM2.5, PM10, SO2, and VOCs in China’s 31 provinces. The spatial correlation analysis using Global and Local Moran’s I values indicates the existence of a significant and positive spatial autocorrelation with respect to environment, economy and energy, and the high spatial correlation is evident in the eastern region, covering the northern part of Yangtze River Delta, Huaihai Economic Zone, and the lower reaches of the Yellow River Economic Belt. The empirical estimation is performed through spatial lag and spatial Durbin models. All emitted air pollutants in 31 provinces have significant spatial dependence and strong spillover effects. There is an inverted U-shaped relationship between emitted air pollutants (NOx, PM10, VOCs, and PM2.5) and per capita GDP, which follows the EKC hypothesis. The relationship between SO2 and per capita GDP does not follow the EKC hypothesis. There is a positive relationship between pollutant emissions and coal consumption, which is consistent with current studies for various countries like Canada, Denmark, UK and US and regions like New York State. However, the effects of science and technology investment on air pollutants are mostly positive, which is not as policy expected.  相似文献   
2.
以中国2013年以来实行的碳排放交易试点政策作为准自然实验事件,基于2000-2017年中国30个省市的面板数据,运用双重差分法实证检验碳排放交易制度的节能减排效应及影响机制。研究发现,碳排放交易制度有利于实现中国经济“节能”与“减排”的双重目标,并通过了一系列稳健性检验;作用机制检验表明,能源效率提升和能源结构转型都是碳排放交易制度实现节能减排目标的重要路径;能源效率提升在碳排放交易制度实现“节能”和“减排”中分别发挥了10.19%和5.93%的作用,而能源结构转型分别发挥了48.87%和52.95%的作用。这意味着中国碳排放交易制度实现节能减排的主要动力来自能源结构转型,而非能源效率提升。能源结构转型涉及问题更加宏观和深层,这为中国加快推进节能减排进程,特别是完成2030年碳达峰和2060年碳中和的国际承诺提供政策启示。  相似文献   
3.
This study investigates the importance of mindfulness‐based organization systems and policies on the organization's continuous efforts to become a greener company. The study is devised as a pooled cross‐sectional time series analysis of productivity in energy consumption, water utilization, and waste generation and recycling of U.S. companies. The data set taken from U.S. Newsweek 500 recorded 600 companies dispersed into 63 industries during the period of 2012–2014 and provided 1,498 company–industry–year observations. The study found that systems and policies (e.g., deployment of third‐party auditors for its environmental metrics report; linkage of the remuneration of company's senior executive team with the achievement of environmental performance targets; and establishment of a committee at the Board of Directors' level whose mandate includes sustainability of the company in environment‐ and resource‐related matters) connect the company's mindfulness to its effort in improving the environmental quality through the company's productivity in energy consumption, water utilization, and waste generation and recycling. The relationships are positive and significant. Also, systems and policies serve as a motivator for the firm to continue to improve upon the current achievements. The study emphasizes the importance of translating organizational and individual mindfulness into organization policies and systems in order to motivate the organization to continuously improve its productivity in energy consumption, water utilization, and waste generation and recycling leading to improvements in environmental quality.  相似文献   
4.
精馏过程的节能,对于减少能源消耗,降低生产成本和保护环境具有十分重要的意义.在精馏过程中可以采用最适宜回流比操作和最佳进料状态,使用中间冷凝器和中间再沸器,高效精馏、热泵精馏.合理安排多组分物料分离流程,直接利用过程热量及开发应用高效换热器等措施.本文从最佳回流比R的选择、进料温度及进料状态的确定等方面,详细的分析了在精馏塔的设计过程中,如何实现设计的优化问题,以实现节能降耗.  相似文献   
5.
Recent approaches to sustainable development leave much room for policies at a local level. In fact, it is becoming evident that targets such as increasing resource productivity, preserving natural cycles, or extending the present level of welfare, are best pursued within the confines of a local area. In particular, environmental changes are best brought about by considering local systems of firms as cornerstones of cooperative strategies and using data on materials and energy use in physical terms. In this paper, an enterprise input–output model is developed for an industrial district, i.e. a local group of firms specialized in the production of a single final output. The model allows for a detailed quantitative analysis of materials and energy flows and the consequent generation of waste and pollution. As a planning tool, the model may be used to evaluate alternative scenarios, such as the possibility of re- using waste taking account of sustainability requirements. An empirical case study applies the model to an industrial district in Southern Italy producing leather sofas.  相似文献   
6.
安徽区域科技基础条件平台建设面临的问题与对策探讨   总被引:7,自引:0,他引:7  
区域科技基础条件平台建设是一项复杂的系统工程,建设工作分为基础性工作和特色性工作的提法有助于地方政府分析条件平台建设的重点和难点.科技条件平台的核心功能之一是以科技资源共建共享的方式向社会提供共性技术尤其是产业共性技术.地方政府解决科技资源供给和需求之间的矛盾的关键在于对共性技术范围进行界定以及确定如何供给共性技术.  相似文献   
7.
This paper presents and analyses the differences in the eco-models implemented worldwide (such as whether and how carbon taxes being "recycled"), or in their efficiency parameters (inconsistent parameter values that account for different results). This is the assumption that a real tradeoff exists between the production of environmental goods. The present article empirically proves that something must be given up in order to gain something else, and once equations are specified to trace out the path of the economy over time, the natural economic formulation of such equations will embody the notion of economic and bio-tradeoffs.  相似文献   
8.
文章从科技人力资源、科技资金资源、科技物质资源和科技信息资源等方面分析了常德市科技资源配置的现状、存在的问题,并提出了相应的对策和建议。  相似文献   
9.
当今物流速度日益加快,仓库建设和改造向空间、立体化、自动化快速发展,建设自动化立体仓库是今后的必然趋势。结合多年实践.对物流领域成件货物储存的新设施,自动化立体仓库进行了详细阐述。  相似文献   
10.
张飞涟  郑颖  顾洋 《基建优化》2006,27(5):83-85
明确了城镇市政设施及城镇市政设施投资项目的定义,分析了城镇市政设施投资项目的特点,揭示了城镇市政设施投资项目后评价的必要性及意义,呼吁全社会重视和关注城镇市政设施项目后评价及城镇市政设施项目的投资效果。  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