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   1298篇
  免费   81篇
  国内免费   2篇
财政金融   44篇
工业经济   382篇
计划管理   433篇
经济学   128篇
综合类   50篇
运输经济   13篇
旅游经济   9篇
贸易经济   101篇
农业经济   112篇
经济概况   109篇
  2024年   5篇
  2023年   14篇
  2022年   34篇
  2021年   48篇
  2020年   41篇
  2019年   21篇
  2018年   16篇
  2017年   36篇
  2016年   42篇
  2015年   72篇
  2014年   155篇
  2013年   111篇
  2012年   140篇
  2011年   141篇
  2010年   108篇
  2009年   59篇
  2008年   60篇
  2007年   50篇
  2006年   50篇
  2005年   55篇
  2004年   28篇
  2003年   25篇
  2002年   17篇
  2001年   7篇
  2000年   16篇
  1999年   10篇
  1998年   4篇
  1997年   4篇
  1996年   5篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1990年   1篇
  1989年   1篇
排序方式: 共有1381条查询结果,搜索用时 125 毫秒
101.
臧树春 《价值工程》2010,29(1):136-136
高瓦斯前进式采煤有效地解决了高瓦斯工作面上转角瓦斯易积聚问题,降低了矿井掘进率,缓解了衰老矿井采煤工作面的接续紧张的状况,可实现煤岩分运,减少煤炭损失。  相似文献   
102.
随着社会生活的进步,信息化、智能化建筑的大量涌现,沿用多年的人工抄表已趋于淘汰。文章在阐述燃气表使用特性基础上从技术的先进性、工程的可靠性和造价的合理性探讨建立远程智能抄表系统的可行性。同时,针对不同住宅类型提出了智能抄表方案的构建框架。  相似文献   
103.
In the inter-stakeholder relations in environmental and natural resource management disputes, farmers and environmentalists have traditionally fallen along opposing lines arguably due to seemingly incompatible values and fundamental differences between the groups. However, the expansion of the coal seam gas (CSG) industry has resulted in outrage and opposition from farming groups, environmentalists, and communities, leading to an alliance of these “strange bedfellows”. This study explored the opposition movement to CSG in Australia with the use of techniques from social psychology to investigate whether shared values provided the common ground for the alliance. An online survey of values was conducted (N = 197) with members of the CSG opposition alliance. No evidence was found to support the hypothesis that this alliance of stakeholders is comprised of two distinct sub-groups; farmers and environmentalists. The personal values of the respondents were highly inter-compatible, and aligned with social altruism. Sub-clusters were identified which corresponded with the extent to which respondents considered the CSG industry to impact on their lives. This research challenges the appropriateness of predetermined stakeholder classifications being applied to environmental and natural resource management issues, and highlights values as a relevant social factor in the cooperation potential of oft-conflicting stakeholder groups.  相似文献   
104.
The growing concerns of climate change require implementing measures to quantify, to monitor and to minimize greenhouse gas (GHG) emissions. Nonetheless, most of the measures available are not easy to define or execute because they rely on current emissions and have a corrective character. To address this issue, a methodology to characterize GHG emissions that allows implementing preventive measures is proposed in this paper. The methodology is related to household urban planning procedures and considers urban infrastructures to characterize GHG emissions and to execute preventive measures based on sustainability design criteria. The methodology has been tested by applying it to a set of medium-sized municipalities with average GHG emissions from 6,822.32 kgCO2eq/year to 5,913.79 kgCO2eq/year for every residential unit. The results indicate that the greatest pollutant source is transport, especially in the issuance of street network design, followed by gas and electricity consumption. The average undevelopable land area required for the complete GHG emissions capture amounts to 3.42 m2 of undevelopable land for every m2 of urbanizable land and 9.02 m2 of undevelopable land for every m2 of built land.  相似文献   
105.
分析了目前原料气罐车三次取样丙烯含量极差较大的问题,阐述了如何改进原料气取样方法,提高丙烯含量分析结果平行性。  相似文献   
106.
文章阐述了汽车时钟弹簧的定义及其在汽车中的应用,并着重介绍了时钟弹簧在汽车应用中的一些失效模式及装配过程中的各项注意事项,提出制造过程的质量控制要求与方法。  相似文献   
107.
The transport phase is one of the crucial stages that can be improved to reduce the environmental impact of the fresh fruit and vegetable supply chain. In this paper, we calculate the environmental impact of feasible logistic alternatives for the above-mentioned supply chain so as to identify the type of transportation that incurs the lowest environmental costs. Specifically, we consider the early potato supply chain as a case study, as it involves one of the main fresh vegetables exported from Italy. Consumers' willingness to pay for the environmental impact of different logistic chains was obtained through life cycle assessment. Our results show that rail transport could reduce environmental impact in terms of tons of oil equivalent, environmental loads, and fuel consumption while ensuring reasonable shipment times. Development of an efficient rail transport system would be positively considered by consumers, enhancing their preferences for Italian products.  相似文献   
108.
李杰 《特区经济》2012,(7):127-130
本文分析了从1949~2010年以来美国实际GDP和美国天然气消费之间的关系,主要运用到了计量经济学中的协整理论和Granger因果关系检验理论。从分析的结果得出,美国天然气消费量和美国经济增长之间是有协整关系的。美国天然气消费量的增长是美国实际GDP增长的原因。美国近年来对天然气的发展做了很大推动,特别是在页岩气方面的技术取得了长足的发展,有效地改善了能源结构。中国也应吸取美国的好经验,大力发展天然气,来应对煤炭的日益减少。  相似文献   
109.
在石油和天然气领域实施低碳策略,对提高能源利用率,降低碳排放具有重要的现实意义。文章概括了我国石油和天然气领域的碳排放现状,结合油气处理终端现状,初步探讨了燃气轮机尾气余热利用的思路和方案,阐述了根据油气生产流程的需求和特点进行预热能量转化的路线,在减少高温排放和碳排放的同时,实现了减少天然气消耗、提高天然气利用率、增加燃气轮机发电功率等目的。结果表明,该研究为全面推动低碳策略在油气生产单位的实际应用奠定了基础。  相似文献   
110.
周艳秋 《价值工程》2012,31(25):48-49
分析了南帕斯凝析油的物理性质及毒害性,针对南帕斯凝析油易挥发的特性在各个作业环节采取有效的安全防护措施、并对储存凝析油的专用储罐进行了优化改进。  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