全文获取类型
收费全文 | 20366篇 |
免费 | 899篇 |
国内免费 | 337篇 |
专业分类
财政金融 | 1329篇 |
工业经济 | 1127篇 |
计划管理 | 5428篇 |
经济学 | 3551篇 |
综合类 | 2125篇 |
运输经济 | 349篇 |
旅游经济 | 714篇 |
贸易经济 | 2715篇 |
农业经济 | 1915篇 |
经济概况 | 2349篇 |
出版年
2024年 | 41篇 |
2023年 | 330篇 |
2022年 | 357篇 |
2021年 | 517篇 |
2020年 | 717篇 |
2019年 | 502篇 |
2018年 | 488篇 |
2017年 | 674篇 |
2016年 | 610篇 |
2015年 | 665篇 |
2014年 | 1575篇 |
2013年 | 1978篇 |
2012年 | 1717篇 |
2011年 | 2128篇 |
2010年 | 1529篇 |
2009年 | 1324篇 |
2008年 | 1410篇 |
2007年 | 1269篇 |
2006年 | 1040篇 |
2005年 | 804篇 |
2004年 | 557篇 |
2003年 | 331篇 |
2002年 | 209篇 |
2001年 | 198篇 |
2000年 | 139篇 |
1999年 | 78篇 |
1998年 | 89篇 |
1997年 | 56篇 |
1996年 | 51篇 |
1995年 | 45篇 |
1994年 | 36篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 17篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
61.
The credit risk contagion of Internet peer-to-peer (P2P) lending platforms is an important part of Internet financial risk management and supervision. This study analyzes the contagion path of credit risk in Internet P2P lending. Based on complex network theory and the theory of infectious disease dynamics, the characteristics of Internet P2P lending development are combined to construct a SEIR model of credit risk transmission among Internet P2P lending platforms with time lag, and the robustness of the model is analyzed and proven. The influence of platform correlations, the susceptible immune rate, the platform elimination rate, contagion latency, the saturation coefficient, and the susceptibility input rate on credit risk contagion behavior among Internet P2P lending platforms is analyzed, using the equilibrium point and threshold value. The impact of each variable is analyzed by simulation. Corresponding countermeasures and suggestions are proposed to prevent and control credit risk contagion among these platforms. 相似文献
62.
以江西省宜春市"月都花溪谷"乡村森林旅游项目规划中哲学元素的应用为个案,结合哲学理论进行分析。结果表明:乡村森林旅游项目规划应有哲学的自觉,根据项目所在地自然和人文资源禀赋,因地制宜地吸收哲学元素,从而打破乡村森林旅游项目同质化和见物不见人的困局,赋予乡村森林旅游项目以特色和灵魂。因此,提出突破森林旅游项目规划中一元化的经济思维定势、以哲学思维唤起人学意义、因地制宜激发内生式哲学文化活性等启发性建议。 相似文献
63.
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
64.
ABSTRACTA key question for promoting international competition is how to improve the position of countries and industries in global value chains (GVCs). The first step is to properly measure industrial upgrading in GVCs. This is not a trivial issue because upgrading has not been defined unambiguously. Several authors have used different (and sometimes related) measures, all of which indicate certain aspects of upgrading. Rather than trying to find the single, ultimate measure of upgrading, we propose a different approach. We examine the multidimensionality of industrial upgrading, using eight indicators in factor analysis. Four of the eight indicators adopt the GVC perspective and include, for example, the growth of the share in value-added exports. We provide three quantitative dimensions of industrial upgrading: process upgrading, product upgrading, and skill upgrading. With these dimensions, we compare and analyze the upgrading of different countries and industries using the World Input–Output Database. 相似文献
65.
[目的]分析评价江苏省现有农田保护经济补偿政策绩效与空间差异对建立完善长效的农业生态补偿机制和推动我国农业生态环境的可持续发展具有重要意义。[方法]以江苏省为研究区域,运用熵权-TOPSIS法,选取2010—2017年全省及苏北、苏中、苏南三个区域内11个指标,计算江苏省及三大区域农田保护经济补偿政策综合绩效值与经济、生态和社会效益单项绩效值,进行比较分析。[结果](1)江苏省农田保护经济补偿政策在2010—2017年8年综合绩效值由0189波动增长到0841,效果初现且具有较强推广价值。(2)经济效益绩效值以年均257%的增长率由0增长到1,效果最为显著,社会效益次之,生态效益自2013年后为绩效值中最低值,与前两项最大差距在05左右,反映出环境改善、农田质量提高效应远低于农户创收、社会公平效应,政策拟合度不高。(3)江苏省农田保护经济补偿政策效果存在空间差异,综合来看政策效果表现为苏南>苏中>苏北,苏南凭借经济优势在2016年和2017年的综合绩效值上比苏中苏北高出01、在经济与社会绩效值以002的差距领先且生态绩效值没有下降拐点,具有长效可持续性。[结论]现阶段农田保护经济补偿政策效果依赖地方政府经济实力,尚未形成良性长效机制,需从制度体系、环境经济手段、差别化补偿措施、农业补贴结构和宣传等5方面着手,推进农田保护经济补偿政策更好地服务生态环境。 相似文献
66.
67.
为了解决在深度学习提取人脸图像特征时,易忽略其局部结构特征和缺乏对其旋转不变性学习的问题,提出了一种基于单演局部二值模式(MBP)与深度学习相结合的高效率人脸识别方法。首先,用多尺度单演滤波器对图像进行滤波,得到幅值和方向信息;其次,用LBP算法和象限比特的方法进行编码,分块计算组合其直方图特征;然后,将提取的单演特征作为深度信念网络(DBN)的输入,逐层训练优化网络参数,得到优异的网络模型;最后,将训练好的DBN网络在ORL人脸数据库上进行人脸识别实验,进行识别率计算,其识别率为98.75%。所提出的方法使用无监督的贪婪算法,隐藏层设定为2层,使用反向传播算法优化网络。相较于已知的人脸识别方法,MBP+DBN算法对光照、表情和部分遮挡变化具有较好的鲁棒性,在人脸识别中识别率较高,具有一定的优势,为图像特征提供了一种新的识别方法。 相似文献
68.
Jrme Hubler Christine Louargant Patrice Laroche Jean‐Nol Ory 《Journal of economic surveys》2019,33(4):1173-1198
The purpose of this study is to examine how credit rating agencies’ decisions impact the stock market using a systematic and quantitative review of existing empirical studies. Specifically, we employ a meta‐regression analysis (MRA) to investigate the extent and nature of the effect of rating agencies’ decisions on the stock market. We survey 62 studies published between 1978 and 2015. Our first finding is that the cumulative average abnormal returns calculated from this empirical literature are affected by publication bias. After controlling for publication bias, the main findings of our meta‐analysis indicate that negative rating decisions cause statistically significant negative abnormal returns. This evidence suggests an informational effect. Our results also indicate that positive rating decisions do not have a significant effect. Finally, the MRA results reveal the importance of several factors related to primary study design, as well as to the nature of the data. 相似文献
69.
By integrating Battese and Coelli’s (1995) model and the spatial autoregressive model (SAR), a spatial autoregressive stochastic frontier model for panel data is developed. The main feature of this frontier model is a spatial lag term of explained variables and the joint structure of a production possibility frontier with a model of technical inefficiency. The model addresses both spatial dependence and heteroskedastic technical inefficiency. This study applies maximum likelihood methods considering the endogenous spatial lag term. The proposed model nests several existing models. Further, an empirical analysis using data on the Japanese manufacturing industry is conducted and the existing models are tested against the proposed model, which is found to be statistically supported. The findings suggest that estimates in the existing spatial and non-spatial models may exhibit bias because of lack of determinants of technical inefficiency, as well as a spatial lag. This bias also affects the technical efficiency score and its ranking. 相似文献
70.
The objective of this research is to identify which are the key variables for designing a message in a social network that can be used by an advertiser to generate Positive/Negative Engagement. The message’s design variables have been classified into four main groups: (i) Message Tools (presence of text, images, video, labels, applications, interactive games and events calendar or others), (ii) Appropriate Message Structure (length and intelligibility), (iii) Informative Cues (links to the brand, orientation towards the product or the brand, topics relevant to the audience, and a remuneration’s promise) and (iv) Persuasive and Emotional Cues (emotional signals, valence, endorsement and influencer mentions). The focus has been a tourist destination: Brand Spain that is advertised through Facebook. A content analysis was carried out and regression analysis with optimal scaling was used on 180 Spain brand’s publications; 57,626 audience reactions to such publications; and 1361 audience comments on the Brand Spain Official Fan Page. According to our results, from the four blocks of predictive variables, only two of them are useful to predict Positive/Negative Engagement: (i) the use of Message Tools (videos), and (ii) the use of informative cues (relevant topics, links on posts, and post’s orientation towards product). 相似文献