全文获取类型
收费全文 | 129篇 |
免费 | 2篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 8篇 |
综合类 | 9篇 |
化学工业 | 12篇 |
金属工艺 | 3篇 |
机械仪表 | 2篇 |
建筑科学 | 7篇 |
矿业工程 | 2篇 |
能源动力 | 5篇 |
轻工业 | 20篇 |
水利工程 | 1篇 |
石油天然气 | 4篇 |
武器工业 | 1篇 |
无线电 | 37篇 |
一般工业技术 | 11篇 |
冶金工业 | 3篇 |
原子能技术 | 2篇 |
自动化技术 | 10篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 7篇 |
2012年 | 2篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有137条查询结果,搜索用时 15 毫秒
1.
红外加热节能技术的现状与发展前景 总被引:1,自引:0,他引:1
本文综述了国内外节能的现状与发展趋势,论述了远红外电加热领域的发展前景,强调了加强基础理论研究的重要性,介绍了我国红外加热应用的领域和国外新开发的红外产品。 相似文献
2.
远红外织物的保健性能 总被引:5,自引:2,他引:3
远红外织物是80年代中期研究开发出的一种通过高效吸收和发射远红外线而具有改善微循环、促进血液循环等功能的新型纺织品。本文通过研究实例综述了国内外近年来对远红外织物保健性能的研究成果。 相似文献
3.
基于工作流技术的多媒体远程教学课件模型的设计与实现 总被引:9,自引:0,他引:9
利用C/S模型开发多媒体教学课件,通过WEB浏览器访问是多媒体教学研究的发展趋势。文章基于面向对象技术,提出了一种集教学,练习,答疑和考试于一体的交互工作流式多媒体教学模型,并利用办公自动化软件LotusNotes/Domino 在大型机S/390上实现了汇编语言的多媒体教学系统。 相似文献
4.
《Fullerenes, Nanotubes and Carbon Nanostructures》2013,21(1-2):263-268
Abstract Inelastic neutron scattering investigations of the orthorhombic (O), tetragonal (T), and rhombohedral (R) pressure‐polymerized phases of C60 as well as the pressure‐dimerized state give evidence for differences in the responses of low‐energy excitations between these phases. These differences are assigned to changes in low‐energy interball modes dynamics as a function of the structure of pressure‐polymerized phases. Far‐infrared transmittance measurements complete the information of the low‐frequency vibrational dynamics of these phases. The temperature dependence of these low‐frequency excitations reveals a strong anharmonicity and possible phase transitions. 相似文献
5.
6.
7.
Molecular-beam epitaxial growth of HgCdTe infrared focal-plane arrays on silicon substrates for midwave infrared applications 总被引:1,自引:0,他引:1
T. J. de Lyon R. D. Rajavel J. A. Vigil J. E. Jensen O. K. Wu C. A. Cockrum S. M. Johnson G. M. Venzor S. L. Bailey I. Kasai W. L. Ahlgren M. S. Smith 《Journal of Electronic Materials》1998,27(6):550-555
Molecular beam epitaxy has been employed to deposit HgCdTe infrared detector structures on Si(112) substrates with performance
at 125K that is equivalent to detectors grown on conventional CdZnTe substrates. The detector structures are grown on Si via
CdTe(112)B buffer layers, whose structural properties include x-ray rocking curve full width at half maximum of 63 arc-sec
and near-surface etch pit density of 3–5 × 105 cm−2 for 9 μm thick CdTe films. HgCdTe p+-on-n device structures were grown by molecular beam epitaxy (MBE) on both bulk CdZnTe and Si with 125K cutoff wavelengths
ranging from 3.5 to 5 μm. External quantum efficiencies of 70%, limited only by reflection loss at the uncoated Si-vacuum
interface, were achieved for detectors on Si. The current-voltage (I-V) characteristics of MBE-grown detectors on CdZnTe and
Si were found to be equivalent, with reverse breakdown voltages well in excess of 700 mV. The temperature dependences of the
I-V characteristics of MBE-grown diodes on CdZnTe and Si were found to be essentially identical and in agreement with a diffusion-limited
current model for temperatures down to 110K. The performance of MBE-grown diodes on Si is also equivalent to that of typical
liquid phase epitaxy-grown devices on CdZnTe with R0A products in the 106–107 Θ-cm2 range for 3.6 μm cutoff at 125K and R0A products in the 104–105 Θ-cm2 range for 4.7 μm cutoff at 125K. 相似文献
8.
This article describes the Russian Far East's energy sector, stressing its limited energy exports, and use of separate electricity and heating grids to geographically dispersed population centers with various supply patterns distributed across a vast territory. One key strategic trend has been to strengthen the potential of the region as an energy supplier for the countries of Northeast Asia. This underlies the framework used to develop three energy scenarios of the Russian Far East's energy future through 2030: Reference, National Alternative and Regional Alternative. While the Regional Alternative case has much greater total costs for implementation, yields almost the same amount of emissions as the BAU case, and requires greater governmental efforts to bring it to reality, it looks preferable for the RFE as a whole because it has a well-balanced primary energy consumption mix, lower energy and ecology/GDP indices, and a lower fraction of energy imports; offers greater diversity of energy supply; and provides better local energy service. The authors would like to thank Boris Saneev, Alexander Sokolov, Alexander Izhbuldin from the Institute of Energy Systems, Irkutsk; Julia Savelieva from Far Eastern Coal Research; and Alla Filatova from Far Eastern Power Engineering Institute for providing technical information, and expertise. 相似文献
9.
这是一个三级近距离及一级远距离通讯系统。近距离通讯采用 RS—232口,远距离采用 RS—422口。本文主要叙述用先进语言 turbo.c 开发通讯程序。这种通讯程序适用性强、简便。既适合近距离,又适合远距离,只要把不同的通讯口地址替换即可。 相似文献
10.
Recent high magnetic field, far infrared transmission and photoconductivity experiments on shallow donor impurities (Si) doped
in the centers of the wells, the centers of the barriers and the edges of the wells in GaAs/AlGaAs multiple-quantum-well (MQW)
structures are described. For donors doped in the centers of the wells, transitions to various high excited states have been
observed. The assignment of these transitions and their relationship to the hydrogenic transitions in bulk (three dimensional)
semiconductors is discussed. The edge-doped samples show dramatic differences in line shape for otherwise identical samples
doped at the top and bottom of the GaAs wells. It is concluded from comparison with model calculations that the Si donors
are redistributed along the growth direction, and such modeling should permit the determination of the impurity distribution
non-destructively. Samples doped in the centers of the barriers show two lines at frequencies lower than that of the well-center
impurities. The dominant line is due to electrons in the wells bound to their parent positive donor ions in the centers of
the barriers. Possible origins of the weaker line are discussed. 相似文献