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   2668篇
  免费   140篇
  国内免费   26篇
财政金融   239篇
工业经济   187篇
计划管理   733篇
经济学   420篇
综合类   184篇
运输经济   45篇
旅游经济   83篇
贸易经济   617篇
农业经济   147篇
经济概况   179篇
  2024年   8篇
  2023年   48篇
  2022年   39篇
  2021年   58篇
  2020年   96篇
  2019年   99篇
  2018年   68篇
  2017年   74篇
  2016年   94篇
  2015年   82篇
  2014年   140篇
  2013年   307篇
  2012年   153篇
  2011年   200篇
  2010年   135篇
  2009年   140篇
  2008年   167篇
  2007年   170篇
  2006年   139篇
  2005年   129篇
  2004年   86篇
  2003年   72篇
  2002年   48篇
  2001年   52篇
  2000年   42篇
  1999年   35篇
  1998年   28篇
  1997年   23篇
  1996年   20篇
  1995年   15篇
  1994年   19篇
  1993年   12篇
  1992年   10篇
  1991年   6篇
  1989年   4篇
  1987年   2篇
  1986年   1篇
  1985年   4篇
  1984年   1篇
  1983年   3篇
  1982年   4篇
  1981年   1篇
排序方式: 共有2834条查询结果,搜索用时 39 毫秒
11.
This study considers a manufacturer with ambidextrous sustainable innovation capability selling products in environmentally conscious market through an independent retailer in a two-period game setting. We design a two-period game theoretic and dyadic supply chain (SC) model considering exploitative and exploratory nature of environmental innovations. We study five different contract types, namely, wholesale price contract, vertical Nash game structure, cost sharing contract, revenue sharing contract and two-part tariff contract. We demonstrate the impact of market sensitivity towards sustainable innovation and cost parameters on optimal level of decision parameters. The equilibrium results reveal that a suitably designed two-part tariff contract can be used to achieve coordination in a fragmented SC. The equilibrium results assist managers to optimise the SC based on the two-period contract model. The results obtained in this study can help the decision-makers to take decisions on investment in the ambidextrous sustainable innovation under different types of contract structures.  相似文献   
12.
决策融合是提高合成孔径雷达(Synthetic Aperture Radar,SAR)目标识别性能的重要手段,然而,可靠性较弱的决策往往会导致最终决策融合的效果变差。将可靠性分析引入基于决策融合的SAR目标识别方法中,分别计算各个决策的可靠性系数并选取可靠性的决策参与最终的决策融合。为了验证方法的有效性,分别将提出的可靠性分析应用于多特征决策融合以及多分类器决策融合并基于MSTAR(Moving and Stationary Target Acquisition and Recognition)数据集进行了目标识别实验。在基于主成分分析、线性鉴别分析和非负矩阵分解三种特征进行多特征决策融合的条件下,所提方法和直接进行决策融合的方法的识别率分别为97.47%和96.50%。在基于K近邻、支持向量机和稀疏表示分类器的多分类器决策融合中,所提方法和直接进行决策融合的方法的识别率分别为97.10%和96.28%。实验结果充分证明了所提方法的有效性。  相似文献   
13.
We investigate determinants of investment decisions in investment‐based (equity and bond) crowdfunding campaigns, using a novel investment‐, investor‐ and campaign‐level database, where equity refers to investments in entrepreneurial start‐ups and bonds to large real estate projects. We find that investors who have higher social interactions invest more. Social interactions are important in an equity crowdfunding context but do not affect participation in bond investments. This is consistent with the view that investors' social networks help reduce information asymmetry. Women invest less in the riskiest (equity) investments but more in safer ones (bonds). These findings are better explained by differences in risk aversion than differences in overconfidence between men and women. Overall, the findings contribute to the understanding of how investment‐based crowdfunding can be a viable source of entrepreneurial finance and how entrepreneurs' campaign decisions affect investor participation in this new form of entrepreneurial finance.  相似文献   
14.
This paper discusses the specifics of forecasting using factor-augmented predictive regressions under general loss functions. In line with the literature, we employ principal component analysis to extract factors from the set of predictors. In addition, we also extract information on the volatility of the series to be predicted, since the volatility is forecast-relevant under non-quadratic loss functions. We ensure asymptotic unbiasedness of the forecasts under the relevant loss by estimating the predictive regression through the minimization of the in-sample average loss. Finally, we select the most promising predictors for the series to be forecast by employing an information criterion that is tailored to the relevant loss. Using a large monthly data set for the US economy, we assess the proposed adjustments in a pseudo out-of-sample forecasting exercise for various variables. As expected, the use of estimation under the relevant loss is found to be effective. Using an additional volatility proxy as the predictor and conducting model selection that is tailored to the relevant loss function enhances the forecast performance significantly.  相似文献   
15.
The competitiveness of tourism destinations is a key issue because it enables destinations to know their position with regard to their competitors. The aim of this paper is threefold: (1) to address the measurement of the competitiveness of tourism destinations at the regional level, (2) to show the suitability of using multi-criteria techniques to measure competitiveness, and (3) to apply the PROMETHEE and GAIA methods within a competitiveness study of eight tourist destinations located in the Northern Region of Portugal. The Metropolitan Area of Porto is the first in the ranking, followed by Cávado and Douro. The results of such an analysis show the comparative strengths and weaknesses of destinations, and allow them to identify their true competitors as well as those other destinations that are most similar to them.  相似文献   
16.
17.
Circular business models (CBMs) have huge potential to deliver economic, social, and environmental benefits, but CBMs have yet to be implemented widely in industrial settings. One reason is that they are often presented as one-size-fits-all solutions, but this is misplaced because product-specific criteria and company capabilities determine the correct choice and implementation of CBMs. Therefore, the purpose of this paper is to investigate how CBM selection and capability development facilitates the implementation of CBMs. For this purpose, we have adopted a qualitative research approach and undertaken 25 explorative interviews in three large Swedish manufacturing companies. In this paper, a CBM implementation framework consisting of two parts has been developed. The first part addresses the choice of the appropriate CBM based on tactical configurations. The second part provides a capability development path by explicating underlying routines that need to be progressively developed in order to move smoothly to more advanced CBMs.  相似文献   
18.
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   
19.
The need and interest to consider cognitive and motivational biases has been recognized in different disciplines (e.g. economics, decision theory, risk analysis) and has recently reached environmental decision-making. Within this domain, the intrinsic presence of a spatial dimension of both alternatives and criteria calls for the use of maps throughout the decision-making process to properly represent the spatial distribution of the features under analysis. This makes spatial Multi Criteria Decision Analysis (MCDA) a particularly interesting domain to explore new dimensions of cognitive biases. This study proposes a behavioral experiment aimed at discovering to what extent the spatial visualization (i.e. maps) of criteria versus the non-spatial one (i.e. tables) can bias the weight elicitation phase of a spatial MCDA process. The experiment simulates a very common analysis in environmental and land use planning: land suitability analysis. Our findings show that there are significant consequences on how important we perceive a certain criterion to be, depending on whether it is represented as a map or as a table among a mix of maps and tables. Indeed, the map representation of the same criterion leads to higher weights attributed to that criterion compared to the table representation. Visualizing the same information as a map or as a table, although technically equivalent, is thus not psychologically equivalent for Decision Makers. The results of this experiment are expected to have implications for spatial decision-making processes, by generating better awareness on the impacts of map-mediated land suitability analysis.  相似文献   
20.
针对斜划分决策树算法普遍存在时间效率低、部分算法仅能应用于二分类问题,提出了一种基于加权距离的聚类决策树算法。通过Relief-F算法为预测属性计算权重,并将权重用于树结点中数据的聚类过程,使用分簇结果对结点进行多路划分,得到可直接用于多分类问题的决策树。理论分析和实验结果表明,该算法与经典轴平行决策树相比,拥有更好的泛化能力以及相近的算法时间复杂度,与大部分斜决策树相比,在付出更少计算代价的前提下,获得了近似的正确率以及模型简洁度。  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