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   22667篇
  免费   1091篇
  国内免费   292篇
财政金融   1641篇
工业经济   1625篇
计划管理   8127篇
经济学   2383篇
综合类   2792篇
运输经济   248篇
旅游经济   875篇
贸易经济   3385篇
农业经济   1227篇
经济概况   1747篇
  2024年   56篇
  2023年   409篇
  2022年   494篇
  2021年   675篇
  2020年   710篇
  2019年   493篇
  2018年   440篇
  2017年   528篇
  2016年   539篇
  2015年   752篇
  2014年   1824篇
  2013年   2169篇
  2012年   1908篇
  2011年   2659篇
  2010年   2062篇
  2009年   1321篇
  2008年   1427篇
  2007年   1229篇
  2006年   1084篇
  2005年   814篇
  2004年   627篇
  2003年   468篇
  2002年   333篇
  2001年   318篇
  2000年   226篇
  1999年   146篇
  1998年   80篇
  1997年   68篇
  1996年   39篇
  1995年   23篇
  1994年   29篇
  1993年   24篇
  1992年   17篇
  1991年   18篇
  1990年   8篇
  1989年   6篇
  1988年   2篇
  1987年   2篇
  1985年   6篇
  1984年   3篇
  1983年   6篇
  1982年   3篇
  1981年   3篇
  1980年   1篇
  1979年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Programs to improve water quality do not improve all water bodies equally. Evaluation of the benefits of such programs must account for where improvements occur and the relative magnitude of improvements that occur in different places. This study uses a choice experiment survey to explore how the value to a household of a surface water quality improvement varies as a function of (i) the distance between the household and the affected streams and rivers, (ii) the degree to which the quality of the water has been improved, (iii) how many stream and river miles have been improved, and (iv) the sizes of the affected streams and rivers. Results show evidence that value declines with distance in an approximately linear way, weak evidence that large rivers are worth more than small rivers, and no evidence that willingness-to-pay is nonlinear in either the degree of water quality improvement or the number of stream miles improved. These results indicate that it may be defensible in applied work to value small, spatially-explicit water quality improvement projects independently and then sum over projects.  相似文献   
2.
传统方法在建筑材料供应链质量数据安全共享中应用效果不佳,不仅数据误码率比较高,而且数据共享时延比较长,无法达到预期的数据安全共享效果。为此提出基于区块链技术的建筑材料供应链质量数据安全共享方法。利用区块链技术对建筑材料供应链质量数据属性加密,建立建筑材料供应链质量数据安全共享链,整合建筑材料供应链质量数据加密、解密程序,通过对用户身份验证实现对质量数据安全共享,以此完成基于区块链技术的建筑材料供应链质量数据安全共享。实验证明,设计方法的数据误码率在1%以内,数据共享时延在1s以内,具有良好的数据安全共享效果。  相似文献   
3.
The panic buying behavior under public health emergencies will lead to many adverse consequences, such as material waste, price fluctuation and uneven distribution of epidemic prevention materials, which will pose a threat to the social stability and economic development. In this paper, we construct a tripartite game model to explore the strategic choices of the public, merchants and the government in order to effectively respond to the panic buying behavior in the epidemic. The results demonstrate that: (1) Eight evolutionary stable strategies emerge in the panic buying events. The worst scenario can be improved by adjusting some relevant parameters. (2) The probability of the public choosing the strategy of “not involving in panic buying” depends on the potential benefits and losses of snapping up, rather than the extent of price rising. (3) The probability of merchants choosing the strategy of “not bid up price” depends on the intangible benefits. (4) The probability of the government choosing the strategy of “active supervision” depends on the supervision costs and government credibility, rather than the amount of fines. In addition, strategic suggestions to mitigate panic buying behavior are put forward from the perspective of each stakeholder.  相似文献   
4.
Are service brands constrained in launching new service offerings? Both research evidence and managerial wisdom suggest brands should extend to similar categories. However, in five studies using real-life brands - four experiments and one large-sample survey - we provide evidence that similarity is less of a constraint for service brands extending to other service categories (service-to-service extensions), compared to cases involving parent brands or extension categories of a product nature. Importantly, we demonstrate that such an effect occurs because service brands possess associations relevant across the spectrum of service categories. Our results suggest that service brand managers have the opportunity to stretch their brands to dissimilar service offerings; yet, they need to ensure the marketing execution does not make the brands’ service associations inaccessible to consumers. The findings suggest that even product brands can build service associations by adding service components to their offering, thus becoming “servitized” and better able to extend to dissimilar service categories. Overall, our work contributes to the academic debate documenting that the principles governing the management of product vs. service brands are not identical.  相似文献   
5.
Predicting consumption behavior is very important for adjusting supplier production plans and enterprise marketing activities. Conventional statistical methods are unable to accurately predict green consumption behavior because it is characterized by multivariate nonlinear interactions. The paper proposes an optimized fruit fly algorithm (FOA) and extreme learning machine (ELM) model for consumption behavior prediction. First, to address the problem of uneven search direction of FOA leading to insufficient search ability and low efficiency, the paper proposes a sector search mechanism instead of a random search mechanism to improve the global search ability and convergence speed of FOA. Second, to address the issue that the initial weights and hidden layer bias values of the ELM are randomly generated, which affects the learning efficiency and generalization of the ELM, the paper uses an improved FOA to optimize the weights and bias values of ELM for improving the prediction accuracy. Taking the green vegetable consumption behavior of Beijing residents as an example, the results show the optimization of the initial weight and threshold of ELM by the GA, PSO, FOA, and SFOA, the prediction accuracy of the GA-ELM, PSO-ELM, FOA-ELM, and SFOA-ELM models all surpass those of ELM. Compared with BPNN, GRNN, ELM, GA-ELM, PSO-ELM, and FOA-ELM models, the RMSE value of SFOA-ELM was decreased by 9.45%, 8.40%, 11.89%, 5.84%, 2.22%, and 2.69%, respectively. These findings demonstrate the effectiveness of the SFOA-ELM model in green consumption behavior prediction and provide new ideas for the accurate prediction of consumption behaviors of other green products with similar characteristics.  相似文献   
6.
In recent years, augmented reality (AR) technology has received considerable attention from academics and practitioners. Although AR technology has a bright side, its dark side has been relatively overlooked. Therefore, this study aimed to investigate the effects of AR technology characteristics on customer citizenship behavior via two conflicting mechanisms: customer immersion and customer fatigue. The study also explored the boundary conditions of customer experience. A total of 247 questionnaires were collected from customers who had prior experience of using IKEA's AR mobile shopping application. A structured model was analyzed using SmartPLS 3 and PROCESS Macro for mediation and moderated mediation effects. The study enriches the current knowledge on AR technology by demonstrating that AR technology can lead to customer citizenship behavior in relation to a brand's AR technology. Interestingly, customer immersion was found to positively mediate the relationship, but customer fatigue was found to negatively mediate it. Furthermore, customer experience was found to strengthen the positive mediation effect of customer immersion and weaken the negative mediation effect of customer fatigue.  相似文献   
7.
发展乡村旅游是实施乡村振兴战略的重要途径,对促进乡村经济发展具有重要作用。以西双版纳傣族园为案例研究地,通过SPSS和AMOS实证探究游客感知视角下乡村旅游质效提升的维度。结果表明:游客感知视角下的乡村旅游质效提升包含旅游地感知、地方认同感、主观幸福感、环境责任行为4个维度;地方认同感和旅游地感知对乡村旅游质效提升的影响力较强,其次是主观幸福感和环境责任行为。  相似文献   
8.
This study details how psychological, financial, and social factors shape employee deviant interpersonal behaviors during a pandemic. Data were collected with a survey of 372 front-line employees of hotels and analyzed with PLS-SEM. The findings showed social disconnectedness and perceived risk of unemployment leads to perceived isolation, which further creates depression in employees. The findings also showed that depression is positively related to employee deviance. Financial strain is a major cause of perceived isolation, depression, and deviant behaviors among front-line employees. Results also proved that social support reduces fear of isolation, depression, and employee deviance. This study provides guidelines that hotels need to understand the psychological stance of employees and design policies to overcome employee perceived fears and psychological disorders.  相似文献   
9.
依托已有的研究成果构建了家政服务人力资源供给质量评价指标体系,利用AHP-TOPSIS模型对京津冀家政服务人力资源供给质量进行了评价和排名,并使用障碍度模型分析了员工制、准员工制、培训学校、中介制四种类型家政机构人力资源供给质量的关键制约因素,在此基础上,给出了不同类型家政机构人力资源供给质量改善的针对性建议,为家政服务人力资源供给质量的改善提供参考依据。  相似文献   
10.
[目的]粮食安全的根本是在耕地,关键在于耕地质量。目前新增耕地主要源于土地开发项目、城乡建设用地增减挂钩土地复垦项目等,这些新增耕地需要对其开展耕地质量等别评定工作,了解新增耕地的质量状况,分析其空间特征,这对落实国家耕地保护制度、开展农村土地整治工作等具有重要作用。[方法]文章以南方典型丘陵区域——江西省宜春市作为研究区域,在新增耕地质量评价的基础上,运用地统计学、景观生态学、Arcgis空间分析技术和典型相关分析方法,研究宜春市新增耕地质量的空间特征,掌握耕地质量等别的分布规律,了解耕地质量的影响因素,为制定合理的耕地资源利用与保护政策提供依据。[结果](1)Moran′s I值结果表明宜春市2014年新增耕地利用质量在空间分布上的空间自相关性最强,而耕地自然质量空间自相关性最弱。(2)景观破碎度指数结果表明优、高等别的新增耕地质量破碎度大于中、低等别的; 多样性指数结果表明新增耕地质量多样性指数比较大; 优势度指数结果表明新增耕地质量等别优势度指数比较小,与多样性指数结果相呼应; 均匀度指数结果表明,新增耕地质量等别均匀度指数相差不大,新增耕地质量等别比较均匀。(3)质心结果表明2013—2014年间宜春市新增耕地质量的格局整体上是向西南方向变化。[结论]宜春市新增耕地质量不高; 新增耕地的利用水平差异性较小,自然本底状况差异较大; 新增耕地质量等别类型多,各质量等别类型耕地均有增加,耕地质量参差不齐,较高等地的新增耕地相对低等地而言更破碎化; 新增耕地的开发格局向着西南方向移动; 该研究为南方丘陵区的新增耕地保护提供了一定的参考依据。  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