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   2530篇
  免费   119篇
  国内免费   85篇
财政金融   74篇
工业经济   276篇
计划管理   610篇
经济学   390篇
综合类   376篇
运输经济   11篇
旅游经济   30篇
贸易经济   525篇
农业经济   84篇
经济概况   358篇
  2024年   10篇
  2023年   27篇
  2022年   24篇
  2021年   20篇
  2020年   44篇
  2019年   48篇
  2018年   37篇
  2017年   43篇
  2016年   53篇
  2015年   73篇
  2014年   121篇
  2013年   192篇
  2012年   165篇
  2011年   200篇
  2010年   177篇
  2009年   171篇
  2008年   247篇
  2007年   216篇
  2006年   250篇
  2005年   187篇
  2004年   134篇
  2003年   103篇
  2002年   64篇
  2001年   38篇
  2000年   24篇
  1999年   12篇
  1998年   16篇
  1997年   6篇
  1996年   5篇
  1995年   4篇
  1994年   4篇
  1993年   6篇
  1992年   6篇
  1991年   4篇
  1990年   1篇
  1986年   1篇
  1985年   1篇
排序方式: 共有2734条查询结果,搜索用时 296 毫秒
71.
结合实际工程的PKPM的电算过程,对框架结构中梁、板、柱各构件选用不同强度等级的混凝土和不同牌号的钢筋分别进行计算。通过将各种构件的计算结果进行对比分析可知,选用高级别的钢筋会明显降低钢筋的用量,同时各种构件的受力性能会随之发生变化。  相似文献   
72.
Building on the resource‐based view (RBV) and competitive dynamics literatures, this paper proposes that considering resources or actions independently offers an incomplete understanding of the drivers of superior performance. Instead, we hypothesize that resources enable competitive actions and that when these actions leverage the firm's resources, superior performance results. We tested these hypotheses with panelized data on the technological resources and competitive actions of firms in the in‐vitro medical diagnostic substance manufacturing industry. The results provide substantial support for our hypotheses, specifically with respect to mediation. Our theory and results underscore how the integration of the competitive dynamics and RBV literatures can significantly improve our understanding of firm performance. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
73.
In the framework of different countries' international comparison, the objective of this paper reflects research topic of investigation--the identification of small countries, revealing features of economic development and business growth in economic history context of small economies classification. The object of investigation focuses on West European and Nordic countries' small economies. The hypothesis of the article is that small states under consideration are developing as the business competitive peripheries areas due to the special Scandinavian capitalist model development characterized by high level of social capital. The statistical data base includes Organization of Economic Cooperation and Development indicators, World Bank parameters and Nordic transnational corporation's annual reports. The paper considers the following research questions: (1) the critical overview of the mainstream academicians opinions concerning different-scaled economies, (2) classification of small states and clarification of different groups of the small-scaled countries role in the world and regional economy through historical context, (3) estimates and variants of small countries' social-economic development in accordance with different parameters, (4) consideration of Nordic European countries coming to the business model of the competitive peripheral social-economic development. The main summing up conclusion is that small economies of Nordic Europe are converting nowadays into the experimental laboratory of the European and world economy due to the specific model of their social-oriented economic and business growth, their geopolitical location between developed European integration complex embracing presumably small-scaled states from one side and large-scaled emerging market economy of Asian continent from the other side.  相似文献   
74.
胡水 《商》2014,(32):81-82
近年来老年人的身体健康现状日益成为人们关注的焦点问题之一,为了对退休老年人的身体健康状况有进一步的了解,对58-68年龄段退休老年人进行身体形态和力量素质的测试。研究发现身高与握力(r=0.659)、体重和握力(r=0.655)均有显著相关性,且呈正相关趋势,身高与体重(r=-0.243)呈负相关。因此在适度原则下,应加强以力量素质为主的体育锻炼,其对于提高身体素质,增进健康有非常重要的意义。  相似文献   
75.
将K-means聚类算法应用到无线局域网(WLAN)位置指纹定位中,虽然可以缩短定位时间,但是容易降低定位精度。为了解决此问题,提出了基于改进指纹聚类的WLAN定位优化方法。首先根据接收信号强度标准差来优化初始聚类中心的选取,然后对指纹数据进行聚类处理,最后进行在线定位。实验结果表明,与传统的WLAN位置指纹定位方法和K-means聚类定位方法相比,基于改进指纹聚类的定位优化方法不仅缩短了定位时间,还能有效提高定位精度。  相似文献   
76.
范春伟 《价值工程》2014,(29):58-60
吊桶是立井井筒开凿时期提升矸石和运送材料及升降人员的主要容器,吊桶的卸矸目前多采用挂钩式或座钩式卸料方式;但是随着矿井的开凿深度不断延伸,在过透水层时,由于探放水不及时或涌出水比较大,超出了井筒的排水量,或者是由于冷冻井在解冻后,井筒的井筒质量不过关,各别井壁也会发生透水事故;这就会出现淹井事故,有时淹井深度达二三百米。对于处理这种淹井事故,往往只有一个办法,那就是用沙或混凝土对井筒回填;这就需要吊桶在下到几百米下的水底自动把料卸掉,但现在矿井常用的挂钩式吊桶和座钩式吊桶已经不能满足这个需要了。  相似文献   
77.
本文在分析和研究煤矿工程造价的基础上,介绍了其含义与职能,并进一步探讨了煤矿工程造价竞标的意义和作用。  相似文献   
78.
王树友 《价值工程》2015,(13):98-100
本文通过试验分析特细砂粒径,不同材质的特细砂的基本物理材性,采用现代混凝土配合比设计理念,研究了特细砂混凝土配合比的设计原则。通过分析砂率含量、用水量、高效外加剂对特细砂高性能混凝土在工作性和力学性能上的影响,确定砂率含量的范围;通过对特细河砂和天然特细山砂混凝土性能的对比试验,结果表明细砂完全可以替代天然中粗砂配制高性能高强度、高流动性泵送混凝土。  相似文献   
79.
The field of international business/economics is largely dualistic in nature. On one hand is the economics literature which has, for two centuries, focused on the notion of comparative advantage (technology, factor proportions) while on the other is the business literature which has recently developed the concept of competitive advantage. This paper presents a reconciliation of the two based on global value chain/supply chain analysis and the concept of vertical comparative advantage. It is shown that the theory of competitive advantage's epistemological comparative advantage lies with its ‘how to’ approach to developing an advantage, while the theory of comparative advantage's epistemological comparative advantage lies with its account of ‘what is’ and that both are complementary. However, it is also argued that the failure to recognize this complementarity as well as the shortcomings of each have prevented and continue to prevent the emergence of an integrated, empirically-consistent theory of international trade – in short, prevented us from taking advantage of the gains from epistemological trade.  相似文献   
80.
In light of the call for companies to abandon current approaches to environmental management, this study adds to the environmental strategy literature and uses the evidence of competitive dynamics among companies to identify a mechanism by which companies invest in proactive environmental strategies and thereby improve the sustainability of the natural environment. An examination utilizing fixed effects regressions on a sample of large U.S.‐based companies reveal that even after controlling the number, environmental and financial performance of leading (environmental) companies, laggard (environmental) companies are more likely to invest in proactive environmental strategies when their leading peers display higher sustainability orientations. Neither the expectation of government regulation nor social movement pressure was found to be influential in this relationship. Therefore, the future dominance of companies' investments in the sustainability of the natural environment will be driven by companies themselves as long as competitive advantages are expected.  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