全文获取类型
收费全文 | 12390篇 |
免费 | 677篇 |
国内免费 | 173篇 |
专业分类
财政金融 | 474篇 |
工业经济 | 990篇 |
计划管理 | 3840篇 |
经济学 | 2023篇 |
综合类 | 1248篇 |
运输经济 | 69篇 |
旅游经济 | 176篇 |
贸易经济 | 2366篇 |
农业经济 | 599篇 |
经济概况 | 1454篇 |
信息产业经济 | 1篇 |
出版年
2024年 | 47篇 |
2023年 | 203篇 |
2022年 | 305篇 |
2021年 | 435篇 |
2020年 | 434篇 |
2019年 | 247篇 |
2018年 | 248篇 |
2017年 | 288篇 |
2016年 | 320篇 |
2015年 | 484篇 |
2014年 | 1134篇 |
2013年 | 1337篇 |
2012年 | 1089篇 |
2011年 | 1263篇 |
2010年 | 1038篇 |
2009年 | 648篇 |
2008年 | 696篇 |
2007年 | 616篇 |
2006年 | 519篇 |
2005年 | 469篇 |
2004年 | 345篇 |
2003年 | 263篇 |
2002年 | 240篇 |
2001年 | 190篇 |
2000年 | 116篇 |
1999年 | 68篇 |
1998年 | 48篇 |
1997年 | 31篇 |
1996年 | 13篇 |
1995年 | 22篇 |
1994年 | 19篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
针对当前摩托车单向器组件主要采用手工装配、装配效率低、随机性大、无法对装配过程实现有效管理控制的情况,为了易于对零件装配过程进行实时监测和提高生产效率,开发了一种智能摩托车单向器自动装配机。介绍了摩托车单向器自动装配机的上料系统、装配系统、检测系统和落料系统的机械结构,重点阐述了设备的气动系统设计,并进行了实验研究。结果表明,该设备可实现组成单向器的5种零件自动上料和装配,同时降低了操作人员的劳动强度,生产效率提高约50%。其气动系统噪音小、工作可靠,可应用于摩托车单向器的大批量生产。研究结果可为其他相似异形零件自动装配机的开发提供参考。 相似文献
22.
Javier Carbonell Antonio Sánchez-Esguevillas Belén Carro 《Technology Analysis & Strategic Management》2018,30(1):113-129
This paper considers the Web as a big data container that can be used by Technology Observatories and administrations to track emerging issues and more specifically emerging technologies. It considers information that is available on the Internet for free from different sources, and proposes a framework that can be useful to characterise them and to detect patterns of dissemination. This framework is made up of 30 metrics obtained from different kinds of sources (general web, patents, scholars?…). Some of them are obtained directly as the number of hits retrieved by queries on a search engine, and other ones calculated by means of ratios. This paper contains the development of a complete case that utilises this framework to characterise emerging technologies included in the well-known Hype Cycle for Emerging Technologies, in this case the 2015 release1 and to analyze patterns of dissemination of these technologies on the Internet. 相似文献
23.
Great hopes have been placed in the sharing economy to provide a new business model based on peer-to-peer (P2P) exchanges of underutilized assets. As a model, the sharing economy has been expected to make significant contributions to sustainability, providing new opportunities for entrepreneurship, more sustainable use of resources, and consumer co-operation in tight economic networks. However, in recent years, digital platforms have turned into the most important actors in the global sharing economy, turning global corporations, such as AirBnB, Booking, or TripAdvisor into intermediaries controlling and profiting from most transactions. Focused on accommodation, this paper conceptualizes the sharing economy in comparison to the wider collaborative economy, and discusses its social, economic, environmental, and political impacts in comparison to the sustainable development goals. It concludes that the sharing economy has great potential to make very significant contributions to sustainability, though the model is increasingly being replaced by the collaborative economy, which performs as an extension and acceleration of neoliberal economic practices. 相似文献
24.
This paper aims to explore the link between creativity orientation, investment in visitors’ experience and operating and funding performance in tourist attractions, taking museums as a case study. The empirical work is based on an analysis of the information provided by a sample of Spanish, French, German, British and American museums. The findings highlight the positive impact of creativity orientation on museums’ operating performance, but show a curvilinear effect on funding performance. The use of new technologies and adaptation to the audience proves positive when seeking to attract visitors. 相似文献
25.
Calvyn Potgieter 《International Journal of Technology and Design Education》2004,14(3):205-218
In this article the impact of technology education, as a new learning area (subject) in the curriculum, on in-service teacher
education in South Africa is described in order to ascertain the extent of the impact. The research on which this article
is based draws on a variety of experiences and observations in the field at grassroots level (in particular an outreach project
in rural communities). The envisaged impact of technology education on South African schools, communities, teacher educators
and teachers, the range of in-service teacher education that is required, and the impacts in urban and rural areas are discussed.
Finally a number of concluding remarks are made about the extent of the impact of the inclusion of technology education in
the new National Curriculum Statement and whether the situation has changed since the implementation of a pilot technology
education project in 1998.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
26.
随着科学技术的不断创新和提高,专利技术的交易越来越频繁,其交易所占贸易的比重也越来越大。文章指出,在专利技术交易发生前后对被交易技术进行必要的产权研究,理顺交易双方的产权关系,明确交易双方的权利和义务,对于交易双方避免交易错位和发生法律纠纷有着重要的指导意义。 相似文献
27.
This paper investigates India's exceptional development pattern, specifically the major importance of information technology services (ITS), and compares it with China's development pattern. Both countries want to develop capabilities for carrying out the innovation of technologies that compete at the state-of-the-art in the world market. The paper posits that technological/economic success in the contemporary world market requires the ability to innovate complex technologies and complex technology-related services. The share of trade represented by complex technologies is compared with the “high-tech” share. The trading patterns of the two countries are compared using United Nations data. Two case studies of Indian ITS companies are then compared with two case studies of Chinese manufacturing companies. Historical and cultural differences appear to explain some of the differences in the development patterns of the companies located in the two countries. 相似文献
28.
讨论了美国NASA深空网(DSN)对深空飞船所采用的同波束干涉(SBI)技术概念和测量原理,并介绍了这一技术的应用和发展情况。 相似文献
29.
对原甲酸三乙酯的原料来源、成本、生产技术信息、技术开发相关情况作了介绍,有益于该产品的生产技术开发。 相似文献
30.