全文获取类型
收费全文 | 259篇 |
免费 | 4篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 12篇 |
综合类 | 14篇 |
化学工业 | 18篇 |
金属工艺 | 6篇 |
机械仪表 | 5篇 |
建筑科学 | 28篇 |
矿业工程 | 1篇 |
能源动力 | 9篇 |
轻工业 | 17篇 |
水利工程 | 4篇 |
石油天然气 | 9篇 |
武器工业 | 3篇 |
无线电 | 20篇 |
一般工业技术 | 17篇 |
冶金工业 | 19篇 |
原子能技术 | 5篇 |
自动化技术 | 82篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 15篇 |
2012年 | 3篇 |
2011年 | 12篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 11篇 |
2003年 | 15篇 |
2002年 | 26篇 |
2001年 | 7篇 |
2000年 | 63篇 |
1999年 | 20篇 |
1998年 | 10篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有269条查询结果,搜索用时 15 毫秒
71.
VoIP用户网关和终端的实现 总被引:2,自引:0,他引:2
本文介绍IP网络替代PSTN网络的技术优势,同时提供了VOIP用户设备解决方案的参考。 相似文献
72.
A concept called fringe compensation was first presented in phase-shifting electronic speckle-pattern interferometry. We apply a similar principle to digital holographic interferometry; here the phase of a wave front is known and can be manipulated. The basic mathematical formulation of fringe compensation and some experimental results are shown with relatively large, simple rigid-body rotation and circular membrane deformation. 相似文献
73.
74.
Robert C. Reference to Szaro David Reference to Langor Atse M. Reference to Yapi 《Landscape and urban planning》2000,47(3-4)
Forests are a global resource and important issues dealing with their use and maintenance cannot be effectively dealt with in an insular fashion. Global participation is mandatory, if these resources are to be sustained and equitably utilized. The seriousness and urgency of most of the forestry and environmental problems are linked to the inability or means of developing countries to provide appropriate scientific and technical knowledge, effective policy, regulations and planning frameworks to deal with the problems. To fully understand and appreciate the challenges to forest science, it is useful to establish an appropriate background against which they should be viewed, and suggest how to improve our capability to deliver knowledge for a sustainable future. There are three keys to making this a reality: information, innovation, and implementation — all derived from human resources. 相似文献
75.
MIAS ARCHITECTS 《景观设计》2014,(4):88-93
该项目旨在对巴尼奥莱斯旧城进行改造,包括将全部的水电管线设置在地下,以及将打造出大面积的步行区。该项目对排水管道也进行了充分的利用,从而产生独特的效果,即重现了建筑在石灰岩之上的中世纪建筑;另外,水是人们生活中的必需品,因此,在该项目中,设计师力图充分利用水以及石材等材料的功能。总之,该项目不只局限于打造出步行区,还要保留旧城里中世纪的建筑布局和风格。 相似文献
76.
2010年9月16-25日,应越南采矿科学技术协会和印尼煤炭协会的邀请,全国政协常委、中国煤炭工业协会会长王显政率代表团赴越南和印尼出席国际会议并考察访问. 相似文献
77.
养基进行了优化。用Plackett-Burman方法对影响发酵各因素的效应进行评价,筛选出有显著效应的3个因素:硫酸铵、葡萄糖和烟酸;通过中心组合实验及响应面分析优化了这3个主要因素。采用优化后的条件进行摇瓶发酵,丙酮酸产量为42.4 g/L。进行5L自控发酵罐发酵,丙酮酸产量为44.8g/L,比优化前提高了16.2%。Application of Response Surface Methodology in Medium Optimization for Pyruvic Acid ProductionZhang Jian Gao Nianfa(Tianjin Key Lab of Industrial Microbiology,College of Biotechnology,Tianjin University of Science and Technology,Tianjin 300222,China)The fermentation medium of(Torulopsis glabrata) TP19 producing 相似文献
78.
Bing Li A. Akintoye P. J. Edwards Corresponding author C. Hardcastle 《Construction Management & Economics》2013,31(5):459-471
Public–private partnerships (PPPs) are increasingly used in the United Kingdom's public facilities and services provision through the Private Finance Initiative (PFI). Despite some casualties, PPP/PFI projects have been undertaken successfully, but the reasons for success are not entirely clear. Questionnaire survey research examined the relative importance of 18 potential critical success factors (CSF) for PPP/PFI construction projects in the UK. The results show that the three most important factors are: ‘a strong and good private consortium’, ‘appropriate risk allocation’ and ‘available financial market’. Factor analysis revealed that appropriate factor groupings for the 18 CSFs are: effective procurement, project implementability, government guarantee, favourable economic conditions and available financial market. These findings should influence policy development towards PPPs and the manner in which partners go about the development of PFI projects. 相似文献
79.
80.
The findings are presented characterizing the immunologic status of peptic ulcer patients during dietetic treatment. The immunologic shifts detected on admission to hospital (increased reactivity of T cells to specific antigen, immunoglobulin imbalance, changed concentrations of some complement components in the blood serum) were found to normalize under the effect of diets. The authors consider that dietetic treatment should be an obligatory component of the comprehensive management of peptic ulcer patients. 相似文献