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   7393篇
  免费   265篇
  国内免费   181篇
财政金融   483篇
工业经济   608篇
计划管理   2509篇
经济学   971篇
综合类   886篇
运输经济   82篇
旅游经济   120篇
贸易经济   1012篇
农业经济   363篇
经济概况   805篇
  2024年   9篇
  2023年   49篇
  2022年   90篇
  2021年   150篇
  2020年   165篇
  2019年   133篇
  2018年   129篇
  2017年   161篇
  2016年   144篇
  2015年   220篇
  2014年   517篇
  2013年   669篇
  2012年   548篇
  2011年   780篇
  2010年   567篇
  2009年   506篇
  2008年   614篇
  2007年   506篇
  2006年   466篇
  2005年   394篇
  2004年   243篇
  2003年   226篇
  2002年   144篇
  2001年   98篇
  2000年   82篇
  1999年   47篇
  1998年   32篇
  1997年   31篇
  1996年   31篇
  1995年   23篇
  1994年   13篇
  1993年   9篇
  1992年   8篇
  1991年   8篇
  1990年   2篇
  1989年   4篇
  1988年   2篇
  1986年   3篇
  1985年   5篇
  1984年   5篇
  1983年   2篇
  1982年   2篇
  1980年   1篇
  1978年   1篇
排序方式: 共有7839条查询结果,搜索用时 15 毫秒
31.
With the expansion of urbanization caused by the growth of population and industrial activities, the urban/city and suburban areas are facing a variety of environmental threats. Although more research and urban policy has advocated and practiced the development of green infrastructure (GI) to support urban sustainable environment, the evaluation framework for the development of GI for promoting environmental sustainability is still insufficient. Moreover, the Analytic Hierarchy Process (AHP) commonly applied in published literature, makes an unrealistic assumption of independent relationships among dimensions/criteria in decision making for satisfying the real-world problem. Therefore, the purpose of this study is to construct the evaluation framework, including four dimensions and related ten criteria, using a new hybrid-modified multiple attribute decision-making (MADM) model for developing and improving the GI for promoting environmental sustainability. This MADM model is combined with three different methodologies of MADM, including the Decision-Making Trial and Evaluation Laboratory (DEMATEL) for constructing the influential network relation map (INRM) to explore the complex influential inter-relationships and DEMATEL based on Analytic Network Process (DANP) for determining the influential weights with the VIse Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR) for evaluating and presenting improvement strategies for six different GIs. The empirical study indicates that DEMATEL and DANP Results suggest that decision-makers should pay more attention to the improvement of Design (D4) and Materials (D2) in terms of dimensions when utilizing the GI to promote environmental sustainability. Because these dimensions are enhanced, Species (D1) and Energy (D3) will be improved in synchronization. From the perspective of criteria, five are key core criteria and need to be focused on first: increasing the green coverage rate (B9), utilizing sustainable materials (B4), using ecological engineering (B8), shaping species biodiversity (B1), and reducing energy consumption (B5). Modified VIKOR reveals that “grass swales” are a comparatively better choice among six GIs for promoting environmental sustainability toward achieving the aspiration level. Therefore, this MADM model is beneficial to provide a more convincing assessment framework and improvement strategies for the development of GI for promoting environmental sustainability. As a result, these modified MADM models can be shown more conveniently and reasonably than traditional methods such as traditional AHP or ANP method.  相似文献   
32.
盐城市水资源承载状态预警研究   总被引:2,自引:1,他引:1  
在分析水资源承载状态预警概念的基础上,引入"三类六级"预警思想,采用可变模糊法和层次分析法的思想,构建盐城市水资源承载状态综合预警指标体系,评价盐城市2015年、2020年和2030年的水资源承载状态,并结合各年份承载状态变化趋势,对未来年份进行预警。结果表明:盐城市2015年水资源处于临界超载的状态,但随着"关于做好建立全国水资源承载能力监测预警机制工作的通知"等一系列措施的实施,2020年、2030年承载状态将逐步好转,到2030年将处于可载的状态。  相似文献   
33.
We develop an algorithm that forecasts cascading events, by employing a Green’s function scheme on the basis of the self-exciting point process model. This method is applied to open data of 10 types of crimes happened in Chicago. It shows a good prediction accuracy superior to or comparable to the standard methods which are the expectation–maximization method and prospective hotspot maps method. We find a cascade influence of the crimes that has a long-time, logarithmic tail; this result is consistent with an earlier study on burglaries. This long-tail feature cannot be reproduced by the other standard methods. In addition, a merit of the Green’s function method is the low computational cost in the case of high density of events and/or large amount of the training data.  相似文献   
34.
We develop an iterative and efficient information-theoretic estimator for forecasting interval-valued data, and use our estimator to forecast the SP500 returns up to five days ahead using moving windows. Our forecasts are based on 13 years of data. We show that our estimator is superior to its competitors under all of the common criteria that are used to evaluate forecasts of interval data. Our approach differs from other methods that are used to forecast interval data in two major ways. First, rather than applying the more traditional methods that use only certain moments of the intervals in the estimation process, our estimator uses the complete sample information. Second, our method simultaneously selects the model (or models) and infers the model’s parameters. It is an iterative approach that imposes minimal structure and statistical assumptions.  相似文献   
35.
This study aims to enhance our understanding of organizational identity work (OIW), building upon previous studies’ emphasis on the usefulness of understanding OIW in terms of storytelling. The paper offers an extended vocabulary for making sense of alternative narration forms. Based on an in-depth study of a humanitarian organization in Sweden, the discursive OIW struggles of employees in times of public disgrace are explored and the following conceptualizations suggested:a) Story-dismantling (attempting to deconstruct a dominant discrediting narrative).b) Story-meandering (attempting to tell a coherent counter-story but without success).c) Story-confirming (claiming that a dominant historical narrative remains valid).These concepts open up and invite considerations of uncertainty, fragmentation, fluidity, and contextuality in future studies of both organizational identity (OI) and OIW.  相似文献   
36.
37.
Abstract

Organizations are constantly searching for ways to enhance their innovative capacity and to sustain their competitive advantage. Much of the literature focuses on knowledge as the key driver for this pursuit. Unlike other studies, we define experience and knowledge as two basic elements of competence by borrowing from the experiential and cognitive learning theories and contrast their impact on the innovativeness of R&D teams. Building on the competence based perspective, we posit that the differences in competence inputs explain variations in team innovation performance along the innovation process. To test our assumptions, we analyzed the aggregated knowledge and experience levels for different technology competences of 868 employees in 49 R&D teams in a large contract-engineering corporation in the medical equipment sector. The findings reveal that technology experience is particularly fruitful within innovation implementation and is a driver for successful market introduction. The research contributes to the understanding when competence elements are especially important.  相似文献   
38.
在PPP项目中,由于政府部门和承包商的目标不一致以及信息不对称等原因的存在,使得在其全寿命周期过程中,承包商的机会主义行为屡见不鲜。本文基于随机演化博弈理论,建构基于Moran过程的博弈模型,旨在探讨推动PPP项目承包商不采取机会主义行为策略的有利条件。研究表明,承包商数目不断扩大,通过降低承包商之间的举报成本,增大惩处力度,可使降低机会主义行为发生概率的效果显著。进一步,借助数值算例,对研究结果进行验证并给出相应的管理对策。  相似文献   
39.
曾向红  陈亚州 《世界经济与政治》2020,(1):102-127,158,159
构建上海合作组织命运共同体是中国政府提出的关于促进上海合作组织长远发展的重大倡议。由于上海合作组织命运共同体理念的提出时日尚短,学术界关于该理念的研究尚未全面启动。要使上海合作组织命运共同体理念成为一个有效的研究议题,不仅需要明晰上海合作组织命运共同体的具体内涵,而且需要将其纳入国际共同体、国际组织和大国外交等议题的研究,提炼出一些具有普遍性的理论命题。就攸关上海合作组织命运共同体构建的重大问题而言,至少需要回答上海合作组织命运共同体提出的理论与实践意义、上海合作组织命运共同体构建应遵循的基本路径、上海合作组织命运共同体构建的基础和条件、上海合作组织命运共同体构建面临的挑战与障碍、学术界能为上海合作组织命运共同体构建提供的对策建议等重大问题。在此过程中,学术界还需将其与周边命运共同体、人类命运共同体等家族相似性的概念纳入同一研究视域,以澄清上海合作组织命运共同体的内涵与外延,辨识上海合作组织命运共同体演变的动力与机制,并从理论层面提炼上海合作组织发展经验的特殊性与普遍性。  相似文献   
40.
使用混合膜生成法和瞬间成皂法配制润肤霜,论文通过单因素试验法探究了1618醇的含量、乳化温度和乳化时间对润肤霜性能的影响。通过对试验数据进行分析得出如下结论:1618醇含量为4.0%、乳化温度为75~80℃、乳化时间为7~9min时产品质量合格,满足QB/T 1857—2013《润肤膏霜》中对性能的要求。  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