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   1378篇
  免费   91篇
  国内免费   1篇
财政金融   116篇
工业经济   135篇
计划管理   626篇
经济学   108篇
综合类   90篇
运输经济   8篇
旅游经济   13篇
贸易经济   143篇
农业经济   138篇
经济概况   93篇
  2024年   8篇
  2023年   23篇
  2022年   34篇
  2021年   40篇
  2020年   33篇
  2019年   20篇
  2018年   27篇
  2017年   35篇
  2016年   35篇
  2015年   84篇
  2014年   168篇
  2013年   140篇
  2012年   167篇
  2011年   170篇
  2010年   110篇
  2009年   86篇
  2008年   55篇
  2007年   56篇
  2006年   41篇
  2005年   40篇
  2004年   26篇
  2003年   22篇
  2002年   14篇
  2001年   13篇
  2000年   7篇
  1999年   4篇
  1998年   3篇
  1997年   5篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
排序方式: 共有1470条查询结果,搜索用时 15 毫秒
41.
We examine the relation between intra-group trust and monitoring in a patriarchal society, and how this relation affects workgroup performance. Data were collected from 352 women who were members of 72 female workgroups in Addis Ababa by means of field experiments and a survey. The data are analyzed using multiple mediation analysis. We find that intra-group trust needs time to develop, and that trust is higher in workgroups with more monitoring. The positive relation between monitoring and trust might be explained by women’s ambition to overcome disempowerment and negative gender stereotypes. The results also indicate positive effects of intra-group trust and monitoring on workgroup performance, and that the effect of monitoring runs through its relation with trust. The last finding stresses the importance of monitoring for developing intra-group trust in these female workgroups.  相似文献   
42.
Due to the advantages of being able to function under harsh environmental conditions and serving as a distributed condition information source in a networked monitoring system, the fibre Bragg grating (FBG) sensor network has attracted considerable attention for equipment online condition monitoring. To provide an overall conditional view of the mechanical equipment operation, a networked service-oriented condition monitoring framework based on FBG sensing is proposed, together with an intelligent matching method for supporting monitoring service management. In the novel framework, three classes of progressive service matching approaches, including service-chain knowledge database service matching, multi-objective constrained service matching and workflow-driven human-interactive service matching, are developed and integrated with an enhanced particle swarm optimisation (PSO) algorithm as well as a workflow-driven mechanism. Moreover, the manufacturing domain ontology, FBG sensor network structure and monitoring object are considered to facilitate the automatic matching of condition monitoring services to overcome the limitations of traditional service processing methods. The experimental results demonstrate that FBG monitoring services can be selected intelligently, and the developed condition monitoring system can be re-built rapidly as new equipment joins the framework. The effectiveness of the service matching method is also verified by implementing a prototype system together with its performance analysis.  相似文献   
43.
The present study aimed to investigate the viable eumycetes population of indoor air sampled in a mass catering plant that produces up to 1200 meals per day. The combination of a culture-dependent and -independent approach applied in the food-processing environment was efficient for the identification of airborne eumycetes. Penicillum, Cladosporium and Alternaria were the dominant genera, while Thysanophora, Aspergillus, Rhizopus, Annulohypoxylon, Arthrinium, Aureobasidium and Trametes were found to be in minority. The size and composition of the eumycetes population found in this study do not raise specific concerns. Nevertheless, a quantitative and qualitative monitoring of these bioaerosol should be included in the progress and criticality reports of the HACCP system in the catering services where eumycetes can pose different risks, such as worsening of the overall quality of meals and/or of the work environment. Indeed, these reports are a useful tool in the preventive HACCP approach, provided that an adequate frequency of sampling is planned in order to quicken the pre-warning process.  相似文献   
44.
We describe counterfeiting activity as the issuance of private money, one that is difficult to monitor. Our approach, which amends the basic random‐matching model of money in mechanism design, allows a tractable welfare analysis of currency competition. We show that it is not efficient to eliminate counterfeiting activity completely. We do not appeal to lottery devices, and we argue that this is consistent with imperfect monitoring.  相似文献   
45.
移动动态安防系统   总被引:1,自引:0,他引:1  
随着个人私有电子设备日益完善,大量隐私信息存储于这些电子设备中,非法的越权访问导致了这类隐私信息的大量流失,本系统实现了远程监控、监督由于时间和空间阻隔而不能实时操控的电子设备的运行状况。  相似文献   
46.
安全监视系统(TSI)是保证汽轮机安全稳定运行的保护系统,包括对汽轮机转子的运行状况进行可靠的连续检测、对汽缸的机械工作参数连续地测量,记录机组启停和运行状态。通过各种TSI探头,汽轮机运转过程中的工况变化产生电信号输入到前置器,为记录、记忆设备提供信号。  相似文献   
47.
我国平安城市监控系统建设日趋普及,但在建设过程中存在财政投入不足而出现分区建设、分区管理的现象。这使得平安城市监控缺乏统一的管理,给城市安全防范工作带来不便。文章根据不同行业的应用需求及特点,提出监控系统整体解决方法,包括对需求的分析、功能实现的方法等。  相似文献   
48.
为了提升车道线检测的准确性和实时性,改良车道偏离预警系统的性能,提出了一种新的车道线识别算法。首先应用投影法对采集到的图像设立感兴趣区域,以此来减少图像中存在的干扰信息;其次应用一种改进后的自适应高斯滤波算法对采集所得图像进行平滑处理,减少图像中不必要的细节;最后采用边缘绘制算法进行边缘检测,在此基础上,提出一种线段检测算法——Edline算法提取边缘线,对检测到的直线段进行筛选和聚类。利用引用计数法对车道线进行跟踪和预测。结果表明,新算法的平均处理时间为17.1 ms,准确率为96.19%,将其应用在车道偏离预警系统中可以有效地提高预警效率,提升预警的准确性和响应速度。研究结果丰富了车道线识别理论,可为车道偏离预警系统的应用及基础研究提供参考。  相似文献   
49.
为了更准确地解析青鳉鱼在突发污染环境中的行为变化趋势,提出了一种基于One-Class SVM模型的青鳉鱼异常行为识别方法。以青鳉鱼的生理及行为特征作为观测指标,将采集到的暴露在不同类型和浓度特征污染物下的青鳉鱼行为强度信号作为经验数据,利用直方图统计和主成分分析(PCA)对行为强度数据进行降维,实现行为特征提取,基于One-Class SVM构建模型,并以五水合硫酸铜和三氯酚作为特征污染物进行暴露实验对算法进行验证。结果表明,One-Class SVM模型可以准确地识别正常行为和污染物暴露时发生的异常行为;对于有机污染物最快可在10 min内完成预警,重金属污染物可在1 h内完成预警,并且污染物浓度越高,模型的识别效果越好。识别方法可对水源突发性水质污染进行更有效的监测和预警,也可为水污染应急决策提供技术支撑。  相似文献   
50.
本文选取2011—2018年度A股上市公司为研究样本,以具有竞争关系的同业公司间的高管连锁作为同业监督的渠道,检验了同业监督对目标公司违规的影响。研究发现:(1)同业监督能有效抑制目标公司违规倾向,且这一影响当且仅当连锁公司是同业公司时存在;(2)同业竞争是同业监督的基础,在行业集中度低和行业增长率低的行业中,同业监督对目标公司违规的抑制作用更强;(3)目标公司的政治关联会瓦解同业监督对公司违规的抑制作用;(4)区分违规行为类型后发现,同业监督对经营违规的抑制作用最强,对信息披露违规次之,对领导人违规几乎没有效果。本研究丰富了公司违规监督机制的内容,也提供了辩证看待高管同业兼任的新视角。  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