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   3321篇
  免费   42篇
  国内免费   2篇
财政金融   150篇
工业经济   180篇
计划管理   651篇
经济学   1446篇
综合类   125篇
运输经济   26篇
旅游经济   34篇
贸易经济   462篇
农业经济   69篇
经济概况   219篇
信息产业经济   1篇
邮电经济   2篇
  2024年   2篇
  2023年   32篇
  2022年   118篇
  2021年   118篇
  2020年   147篇
  2019年   122篇
  2018年   104篇
  2017年   130篇
  2016年   160篇
  2015年   90篇
  2014年   176篇
  2013年   191篇
  2012年   230篇
  2011年   329篇
  2010年   203篇
  2009年   219篇
  2008年   229篇
  2007年   174篇
  2006年   129篇
  2005年   100篇
  2004年   52篇
  2003年   51篇
  2002年   29篇
  2001年   16篇
  2000年   16篇
  1999年   23篇
  1998年   42篇
  1997年   28篇
  1996年   12篇
  1995年   3篇
  1994年   10篇
  1993年   10篇
  1992年   5篇
  1991年   9篇
  1990年   6篇
  1989年   6篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   7篇
  1984年   20篇
  1983年   6篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   2篇
排序方式: 共有3365条查询结果,搜索用时 671 毫秒
111.
近年来物联网技术受到人们普遍关注。通过对铁路物流现状的分析,结合物联网技术,提出适合铁路物流的方案,来实现铁路物流的可视化、一体化,提高铁路物流的效率。  相似文献   
112.
王建博  王鹏  兰正升 《价值工程》2011,30(27):48-49
苏里格气田地质结构较为复杂,钻采开发以定向井和水平井为主,本文主要是针对定向井施工的工艺技术进行分析探讨,探讨了制约技术提速的瓶颈所在,分析了在不同地层、井深选用不同的钻头及钻具结构及井眼轨迹对提高钻井速度的影响,形成了一套成熟的钻井思路及配套技术;同时也探索了定向井新的提速思路,为下一步持续提速明确了主攻方向。  相似文献   
113.
吴东鹏  袁野  张正利  刘西潼  王健 《价值工程》2011,30(29):160-161
针对现有内河航运船舶过闸管理存在工作效率较低,安全性较差,服务不到位等问题,提出基于RFID和GSM的船舶过闸辅助调度系统。以船舶预调度和自动过闸方式对带有芯片的船舶进行自动识别,读取数据;对遇到相关异常情况及时进行处理;根据船舶相关属性信息安排过闸调度,实现自动收费。并对该系统的基本工作原理、整体结构和实现方案等问题进行论述。  相似文献   
114.
杜江  万宏强  曹岩 《价值工程》2011,30(18):176-177
针对上世纪末以来制造业在人类科技快速发展带动之下所产生的深刻变化,本文以机械制造及其自动化专业方向学生综合素质的提高为目标,在深入分析现代制造属性、特征的基础上,从深化学生主观认知的角度探讨了关于现代制造观的培养问题。  相似文献   
115.
赵小希 《价值工程》2011,30(28):127-128
随着当代信息技术和因特网的蓬勃发展,网络学习凭借其数字化、多媒体化、信息量大、交互性强、覆盖面广等特点,成为现代远程教育中具发展前途的教育模式。该文根据网络技术、数据库技术的特点分析并提出了基于数据库的多媒体网络学习系统设计思路和实现方法。该系统充分发挥了网络的通讯作用;同时吸取了传统学习的优势,克服了传统学习的不足,并通过计算机文化基础课实例进行了有效验证。  相似文献   
116.
The strategic importance of monitoring technological changes is highlighted given the ever faster pace and increasing complexity of technological innovation. In this respect, patent citation analysis has been the most frequently adopted tool among others. However, patent citation analysis is subject to certain drawbacks that stem from only consideration of citing-cited information and time lags between citing and cited patents. This study proposes a formal concept analysis (FCA)-based approach to developing a dynamic patent lattice that can analyze complex relations among patents and monitor trends of technological changes. The FCA is a mathematical tool for grouping objects with shared properties based on the lattice theory. The distinct strengths of FCA, vis-á-vis other methods, lie in structuring and displaying the relations among objects from a massive amount of data. For the purpose of technology monitoring, the FCA is modified to take into account time periods and changes of patent keywords. A patent context is first constructed with the aid of domain experts and text mining technique. Two types of dynamic patent lattices are then developed by executing the modified FCA algorithm. A case study of laser technology in lithography for semiconductor manufacturing shows that the suggested dynamic patent lattice has considerable advantages over conventional patent citation maps in terms of visualization and informative power.  相似文献   
117.
Technology has been the driving force of development for knowledge-based economies. As competition in technology innovation among nations becomes more intense, there is a growing need for improved judgment, evaluation and prediction of scientific technology capacity in order to enhance national competitiveness. Until now, a country's technology level has been evaluated on a relative basis by comparing it with that of the country with the world's best technology. However, this kind of static methodology makes the interpretation of results unclear and makes time series analysis difficult. One of the most important limitations of this methodology is that it cannot be used to establish a strategy to improve the technology level. This paper examines the methodological problems of technology level evaluation and develops a dynamic methodology by applying the technology growth curve model. We also analyze the real technology level by using a new model application and review the relevance of this method. Finally, we discuss how to use the results in order to create a dynamic technology strategy.  相似文献   
118.
Technology evaluation, as an organizational process, is the essential ability to comprehend the values of technologies very soon after they emerge. Meanwhile, the technology evaluation process is inevitably influenced by the firm's industrial context, such as its technological trajectory. This study defines technology evaluation strategy in terms of the processes, methods, and participants involved, and uses this definition as a taxonomy to explore different types of technology evaluation strategies. A survey on the technological industries is conducted to explore types of technology evaluation strategies and their relationships with the advantages of different types of innovation under the effects of different technological trajectories. The survey identifies four types of technology evaluation strategies, namely, those of the flexible executive strategist, the emergent executive intuitionist, the deliberate quantitative strategist, and the deliberate consensual strategist, are identified. This study has found that certain types of technology evaluation strategies have better innovation performances than the others. The patterns of technological trajectories are also found to influence a firm's technology evaluation strategy and the advantages of certain types of innovations. The established explanations of the relationships among the technological trajectory, innovation type, and technology evaluation strategies may guide technology businesses to develop a better technology evaluation capability. The theoretical framework developed in this research enriches the strategic management literature with a new taxonomy for technology evaluation strategies.  相似文献   
119.
In the last three decades much knowledge has been produced on how best to conduct foresight exercises, but little is known on how foresight should be integrated with the innovation effort of a company. Drawing on empirical evidence from 19 case studies and 107 interviews, we identify three roles that corporate foresight should play to maximize the innovation capacity of a firm: (1) the strategist role, which explores new business fields; (2) the initiator role, which increases the number of innovation concepts and ideas; and (3) the opponent role, which challenges innovation projects to increase the quality of their output.  相似文献   
120.
Patent indicators for monitoring convergence - examples from NFF and ICT   总被引:2,自引:0,他引:2  
The blurring of boundaries between hitherto distinct scientific disciplines, technologies or markets is a common and powerful phenomenon. Concentrating on monitoring convergence through patent indicators, we discuss convergence with examples from the area of Nutraceuticals and Functional Foods (NFF)/Cosmeceuticals as well as information technologies, consumer electronics, and telecommunications (ICT). We analyze 7455 scientific and patent references on phytosterols with the aid of SciFinder Scholar and 3836 documents employing STN AnaVist. Furthermore, we test an IPC co-classification based approach on 859,469 ICT-related and 341,846 NFF-related patents. Our results show clear indications for convergence and a proof of principle for our monitoring concept. Academics may better evaluate environmental parameters, like cases of convergence, influencing companies' actions. Implications for practitioners are based on a more reliable assessment prior to the forming of strategic alliances or mergers and acquisitions. This could help avoid costly adventures such as the mergers and acquisitions seen in ICT.  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