全文获取类型
收费全文 | 6354篇 |
免费 | 276篇 |
国内免费 | 201篇 |
专业分类
电工技术 | 386篇 |
技术理论 | 1篇 |
综合类 | 1015篇 |
化学工业 | 178篇 |
金属工艺 | 49篇 |
机械仪表 | 299篇 |
建筑科学 | 1000篇 |
矿业工程 | 151篇 |
能源动力 | 198篇 |
轻工业 | 175篇 |
水利工程 | 108篇 |
石油天然气 | 131篇 |
武器工业 | 13篇 |
无线电 | 641篇 |
一般工业技术 | 416篇 |
冶金工业 | 428篇 |
原子能技术 | 69篇 |
自动化技术 | 1573篇 |
出版年
2025年 | 24篇 |
2024年 | 55篇 |
2023年 | 61篇 |
2022年 | 86篇 |
2021年 | 158篇 |
2020年 | 174篇 |
2019年 | 119篇 |
2018年 | 106篇 |
2017年 | 128篇 |
2016年 | 159篇 |
2015年 | 178篇 |
2014年 | 404篇 |
2013年 | 458篇 |
2012年 | 429篇 |
2011年 | 463篇 |
2010年 | 362篇 |
2009年 | 423篇 |
2008年 | 385篇 |
2007年 | 409篇 |
2006年 | 360篇 |
2005年 | 319篇 |
2004年 | 322篇 |
2003年 | 293篇 |
2002年 | 242篇 |
2001年 | 195篇 |
2000年 | 98篇 |
1999年 | 95篇 |
1998年 | 50篇 |
1997年 | 47篇 |
1996年 | 42篇 |
1995年 | 37篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1971年 | 3篇 |
1968年 | 4篇 |
1965年 | 5篇 |
1963年 | 4篇 |
1961年 | 5篇 |
1959年 | 3篇 |
1954年 | 3篇 |
排序方式: 共有6831条查询结果,搜索用时 15 毫秒
101.
In response to energy market liberalisation and privatisation initiatives promoted by the EU and other European states in the 1990s, a large number of US energy utilities expanded their activities in Europe, mainly through acquisitions. The size of their investment was, a decade later, matched by the ensuing scale of their retreat, wealth destruction and often forced exit. Combining interviews, industry studies, published financial data and company reports, this article examines critically their strategy and, in light of widespread failures, seeks to answer the question of what went wrong. It is argued that mistakes might have been avoided through greater appreciation of how market liberalisation evolves given changing government priorities and general sovereign risk. 相似文献
102.
This paper reviews the trends in society, technology and energy demand of the past 30 years, together with the growth of the ‘on-demand’ culture. The ‘24/7’ or ‘always on’ society can be defined as one where people demand—and generally receive—what they want ‘now’. It has grown up in parallel with developments in information technology, which have produced the services needed to meet that demand. Larger numbers of appliances, resulting from greater affluence and disposable income, have increased energy use, despite energy efficiencies in other areas. While monetary factors suggest that changes brought about by the 24/7 society will generally be self-correcting at the macro-economic level, there will nevertheless be effects for individuals, such as potentially severe impacts on the fuel poor as electricity prices rise. 相似文献
103.
为了实现基于企业服务总线(ESB)的企业服务集成应用(EAI),提出一种基于ESB的业务流程管理系统的设计方法.定义了业务流程的概念,提出在ESB下实现流程管理的方法,同时,研究并给出了业务流程监控的方案.目前,该系统已经在国家基金项目中得到了应用.实际应用表明,所研究的相关系统灵活,可靠,并具有实用价值. 相似文献
104.
Struts框架具有组件的模块化、灵活性和重用性等优点,同时简化了基于MVC的Web应用程序的开发。文中将Struts框架技术运用到电子商务Web系统的设计与开发中,有效地分离出系统的界面显示和业务逻辑处理,降低了系统开发及维护代价,同时大大提高了系统的可重用性。 相似文献
105.
孙宏滨 《数字社区&智能家居》2009,(19)
随着黑龙江邮政企业综合服务业务发展和企业信息化的开展,建立邮政综合服务平台有着重要的意义。该文从网络结构和平台总体设计等方面进行了分析,并总结出平台的若干特点和适用领域。 相似文献
106.
No authorship indicated 《Canadian Metallurgical Quarterly》2009,64(8):822
Judith V. Torney-Purta, recipient of the Award for Distinguished Contributions to the International Advancement of Psychology, is cited for leadership of rigorous research on the development of democratic attitudes and civic knowledge among adolescents from more than 30 countries that has served as a catalyst for education and youth policy reform. Torney-Purta led research projects that are prime examples of international collaboration. She drew on these experiences in contributing to an initiative on international collaboration among behavioral and social scientists sponsored by the U.S. National Committee for the International Union of Psychological Science. Along with the citation, a biography and selected bibliography of Torney-Purta's works are presented. Also included is her paper, entitled International psychological research that matters for policy and practice, a version of which she presented at the American Psychological Association's annual convention. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
刘娟 《数码设计:surface》2009,(10):290-292
从古至今,人类离不开衣;现代社会,服装更是充斥生活的每一角落,品牌种类名目繁多,令消费者眼花缭乱,品牌竞争也不断白热化。企业的最终目的是使自己的品牌在竞争中大放异彩,那么怎样合理有效的推广服装品牌,在推广中如何利用商业形象是本篇文章要讨论的问题。 相似文献
108.
作为方法论,博弈论从它诞生之日起就被广泛地应用着,它不仅与现代经济活动紧密相关,而且融入企业管理活动之中,成为现代企业管理成败的关键因素之一。本文试图从古诺产量决策模型的博弈实例,进一步阐述博弈论在现代企业管理中不可或缺的作用。 相似文献
109.
Rogério Fernandes Brito Solidônio Rodrigues de Carvalho Sandro Metrevelle Marcondes de Lima e Silva João Roberto Ferreira 《International Communications in Heat and Mass Transfer》2009
This work studies the heat influence in cutting tools considering the variation of the coating thickness and the heat flux. K10 and diamond tools substrate with TiN and Al2O3 coatings were used. The numerical methodology utilizes the ANSYS® CFX software. Boundary conditions and constant thermo physical properties of the solids involved in the numerical analysis are known. To validate the proposed methodology an experiment is used. The TiN and Al2O3 coatings did not show satisfying results during a continuous cutting process. It showed a slight reduction in the heat flux for the 10 (µm) TiN and Al2O3 coatings. 相似文献
110.
This paper examines international treaties in relation to the threat or use of nuclear weapons including the 1968 Nuclear Non-Proliferation Treaty and the 1996 Comprehensive Test Ban Treaty. It can be concluded that the effect of the aforesaid international treaties is still in doubt without explicit enforcement mechanisms and penalty for non-compliance. This paper also reviews the International Court of Justice's advisory opinion on the legality of the threat or use of nuclear weapons and comments that a clear explanation on the legality of use of nuclear weapons in ‘extreme circumstances of self-defence’ is required. Examples from current state practice in relation to nuclear non-proliferation efforts are also provided, with special attention to China, North Korea and Iran. This paper suggests that China as a leader of developing countries should extend its efforts on nuclear non-proliferation and conduct communication between North Korea and Iran and other nuclear weapons states to reduce or prohibit nuclear weapons. 相似文献