全文获取类型
收费全文 | 2488篇 |
免费 | 136篇 |
国内免费 | 90篇 |
专业分类
电工技术 | 44篇 |
综合类 | 201篇 |
化学工业 | 361篇 |
金属工艺 | 29篇 |
机械仪表 | 37篇 |
建筑科学 | 328篇 |
矿业工程 | 76篇 |
能源动力 | 27篇 |
轻工业 | 344篇 |
水利工程 | 19篇 |
石油天然气 | 21篇 |
武器工业 | 4篇 |
无线电 | 100篇 |
一般工业技术 | 224篇 |
冶金工业 | 537篇 |
原子能技术 | 2篇 |
自动化技术 | 360篇 |
出版年
2024年 | 9篇 |
2023年 | 49篇 |
2022年 | 56篇 |
2021年 | 76篇 |
2020年 | 101篇 |
2019年 | 52篇 |
2018年 | 67篇 |
2017年 | 64篇 |
2016年 | 59篇 |
2015年 | 81篇 |
2014年 | 168篇 |
2013年 | 143篇 |
2012年 | 176篇 |
2011年 | 226篇 |
2010年 | 167篇 |
2009年 | 154篇 |
2008年 | 103篇 |
2007年 | 146篇 |
2006年 | 156篇 |
2005年 | 119篇 |
2004年 | 108篇 |
2003年 | 89篇 |
2002年 | 64篇 |
2001年 | 59篇 |
2000年 | 42篇 |
1999年 | 37篇 |
1998年 | 23篇 |
1997年 | 15篇 |
1996年 | 19篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1963年 | 2篇 |
1956年 | 1篇 |
1955年 | 3篇 |
排序方式: 共有2714条查询结果,搜索用时 15 毫秒
41.
膜法富氧技术及其应用研究 总被引:12,自引:0,他引:12
介绍了作者在膜法富氧技术方面的研究进展,并将膜法与其他制氧方法进行了比较,最后讨论了膜法富氧技术目前的有关应用,着重研究了膜法富氧在有色金属冶炼,硅酸盐窑炉,化铁炉,加热炉,医疗保健和柴油机增氧等方面的典型应用。 相似文献
42.
多不饱和脂肪酸,特别是ω-3系列的多不饱和脂肪酸对神经系统有着极其重要的作用,能够保护多巴胺能神经元、增强大脑活力、提高学习能力,尤其对胎儿及婴幼儿的大脑发育有很强的促进作用.多不饱和脂肪酸对视神经有保健作用,对神经系统肿瘤、精神性疾病也有较好的预防和治疗作用. 相似文献
43.
《Ergonomics》2012,55(12):1617-1631
Abstract Intrinsic thermal clothing insulation and surface air insulation were measured on human subjects by the use of indirect calorimetry. Four male clothing ensembles (0-1-1 -8 clo) and three female clothing ensembles (0-2-1-2 clo) were investigated. Using the standing position as a reference, the influence of sitting, bicycling (40r.p.m., 20 W), walking (3-75 km hour?1) and of light packing work on the thermal insulation was studied. The influence of an air velocity of 11ms?1 on thermal insulation during the standing and walking conditions was investigated. The results showed that: (i) intrinsic clothing insulation was maximal in the standing position. It was reduced by 8-18% in the seated position and by 30-50% during bicycling and walking. An air velocity of 11ms?1 did not influence the intrinsic clothing insulation during walking, but decreased it by 18% in the standing position; (ii) surface air insulation varied with activity and air velocity, but not with clothing. It was increased by up to 25% in the seated position, reduced by 7-26% during bicycling and by 30-50% during walking. An air velocity of 11 ms-1 reduced the surface air insulation by 50% in the standing position and 30% during walking. 相似文献
44.
数字内容产业是新兴产业,以其高科技、高附加值和环境友好等特征成为现代服务业的重要组成部分。介绍我国数字内容产业发展现状及存在差距的基础上,分析数字内容产业在我国发展面临的困境,有针对性地提出我国数字内容产业的发展对策。即增强政府部门间协调管理,加大政策扶持力度;加强市场监管和标准体系建设,规范市场秩序;创新融资方式,建立多元化投融资机制;探索成功商业模式,摆脱低效益发展困境;构建数字内容产业链,发展产业集群;完善数字内容人才培养机制,保证人才供给;增强知识产权保护力度,健全法律法规环境等。 相似文献
45.
成曦 《湖南纺织高等专科学校学报》2012,(3):16-19
社区居家养老模式适合我国现阶段的国情,能够有效缓解人口老龄化对我国经济、社会等各方面造成的冲击,但是从各地社区居家养老的实践来看,还存在着不少的问题与缺陷。因此,需要对社区居家养老模式进行大胆的创新,改变以往对政府依赖性强,发展动力不足的现状,借助市场化的力量,充分发挥物业服务企业在社区居家养老中的天然优势,以使社区居家养老具备更好的可操作性和适用性。 相似文献
46.
The knowledge intensive service processes should be managed in a human-oriented way since humans who naturally undertake complex operations of an intellectual nature in the processes are the most valuable resources. The most fundamental nature of human work is collaborative and dynamic. Humans interact and communicate with each other to accomplish their jobs in the process. To help them to work together, a strong representation of the process should be provided to facilitate them to clearly understand who they should interact with and what activities need to be performed. For the clear representation, Human Interaction Management (HIM), which has been suggested to comprehensively support human work, adopts a role-based approach to process modeling. It, however, tends to hide elements of interactions although the collaborative human interaction is one of the most fundamental nature of human work. To remedy this problem, a state-driven modeling approach to human interactions was presented. It clearly visualizes the interactions so that humans can be guided through it. However, they do not just follow the previously defined sequence of activities, but continuously work out how they are going to proceed from now on according to the state of things they encounter throughout the life of the work. To fully support the dynamic nature of human work, human interactions should be flexibly managed. Therefore, this paper presents a framework for the flexible management of human interactions. The framework provides a capability to flexibly manage the interactions in a decentralized way by allowing interaction participants to dynamically change the involved interaction based on the continuous negotiation of how to achieve the ultimate goal of the interaction. It will be a basis for realization of decentralized management of human interactions in knowledge intensive service processes. 相似文献
47.
大量的大规模密集型数据需要存储在多个数据存储中心,而应用越来越广泛的云计算环境很好地解决了大规模密集型数据在分配中遇到的规模性问题。但是,云计算环境中多数据存储中心的数据分配会带来数据存储中心之间数据量的传输,从而导致数据访问效率低下。同时,单位时间上数据访问量的不平衡性会引起数据存储中心的访问瓶颈。以大规模密集型数据中的数据流为建模对象,提出了一种数据分配算法,它在保证数据存储中心负载平衡的基础上兼顾了密集型数据之间的依赖性。实验表明,相比于同类的数据分配算法,所提算法具有更好的综合表现,特别是在保证数据存储中心的负载平衡方面,效果突出。 相似文献
48.
膜法富氧在国内应用新进展 总被引:3,自引:0,他引:3
膜法富氧及其助燃技术的应用非常广泛。主要介绍了膜法富氧技术在国内玻璃窑、锅炉、注汽炉、热风炉、医疗保健和FCC富氧再生等方面应用的最新进展。 相似文献
49.
赵爱萍 《杭州电子科技大学学报》2005,(4)
阅读是语言输入和积累的主要来源。本文从第二语言习得的角度,以克拉申强调的语言输入为切入点,探讨语言输入的有效途径———阅读输入强化。从而说明:阅读是语言输入的最佳有效方式。阅读输入强化为习得者提供了最佳习得机会。 相似文献
50.
Schwebel David C.; Brezausek Carl M.; Ramey Craig T.; Ramey Sharon L. 《Canadian Metallurgical Quarterly》2005,24(5):501
The number of immigrants in the United States is at an all time high, yet psychologists have largely ignored the domain of immigrant health. This article considers 1 aspect of immigrant health, risk for pediatric injury. A sample of over 5,000 5-year-old children from impoverished families was studied; approximately 13% had immigrant mothers. Children of immigrants had a significantly lower rate of injury in the prior year. This was particularly true of non-White children of immigrants. Three possible mediators for this finding--assistance with parenting, parenting style, and health care accessibility--were considered, but none explained the difference. The need for further research on the topic and implications of results for injury prevention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献