全文获取类型
收费全文 | 181篇 |
免费 | 5篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 19篇 |
金属工艺 | 5篇 |
机械仪表 | 1篇 |
建筑科学 | 5篇 |
能源动力 | 2篇 |
轻工业 | 5篇 |
水利工程 | 1篇 |
无线电 | 13篇 |
一般工业技术 | 83篇 |
冶金工业 | 45篇 |
原子能技术 | 1篇 |
自动化技术 | 4篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 6篇 |
2008年 | 16篇 |
2007年 | 10篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 11篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1967年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有186条查询结果,搜索用时 156 毫秒
181.
Borgström MT Norberg E Wickert P Nilsson HA Trägårdh J Dick KA Statkute G Ramvall P Deppert K Samuelson L 《Nanotechnology》2008,19(44):445602
The use of tetraethyltin (TESn) and dimethylzinc (DMZn) as in situ n-?and p-dopant precursors during particle-assisted growth of InP nanowires is reported. Gate voltage dependent transport measurements demonstrate that the nanowires can be predictably synthesized as either n-?or p-type. These doped nanowires can be characterized based on their electric field response and we find that n-type doping scales over a range from 10(17) to 10(19)?cm(-3) with increasing input TESn dopant molar fraction. On the other hand, the p-type doping using DMZn saturates at low levels, probably related to a strong increase in nanowire growth rate with increasing DMZn molar fractions. By optimizing growth conditions with respect to tapering, axial pn-junctions exhibiting rectifying behavior were fabricated. The pn-junctions can be operated as light emitting diodes. 相似文献
182.
We observe spin-valve-like effects in nanoscaled thermally evaporated Co/AlOx/Au tunnel junctions. The tunneling magnetoresistance is anisotropic and depends on the relative orientation of the magnetization direction of the Co electrode with respect to the current direction. We attribute this effect to a two-step magnetization reversal and an anisotropic density of states resulting from spin-orbit interaction. The results of this study points to future applications of novel spintronics devices involving only one ferromagnetic layer. 相似文献
183.
Mølhave K Wacaser BA Petersen DH Wagner JB Samuelson L Bøggild P 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(10):1741-1746
Free-standing epitaxially grown nanowires provide a controlled growth system and an optimal interface to the underlying substrate for advanced optical, electrical, and mechanical nanowire device connections. Nanowires can be grown by vapor-phase epitaxy (VPE) methods such as chemical vapor deposition (CVD) or metal organic VPE (MOVPE). However, VPE of semiconducting nanowires is not compatible with several microfabrication processes due to the high synthesis temperatures and issues such as cross-contamination interfering with the intended microsystem or the VPE process. By selectively heating a small microfabricated heater, growth of nanowires can be achieved locally without heating the entire microsystem, thereby reducing the compatibility problems. The first demonstration of epitaxial growth of silicon nanowires by this method is presented and shows that the microsystem can be used for rapid optimization of VPE conditions. The important issue of the cross-contamination of other parts of the microsystem caused by the local growth of nanowires is also investigated by growth of GaN near previously grown silicon nanowires. The design of the cantilever heaters makes it possible to study the grown nanowires with a transmission electron microscope without sample preparation. 相似文献
184.
Dick KA Deppert K Karlsson LS Seifert W Wallenberg LR Samuelson L 《Nano letters》2006,6(12):2842-2847
We demonstrate here a method for controlled production of complex self-assembled three-dimensional networks of InAs nanowires on a substrate, based on sequentially seeded epitaxial nanowire structures, or "nanotrees". A position-controlled array of trunk nanowires is first produced using lithographically defined Au particles as seeds. With these wires positioned along the proper crystallographic directions with respect to each other, nanotree branches grow toward neighboring trunks, connecting them together. Finally, we investigate the crystal structure of the interconnected nanotrees, demonstrating that branch growth after the contact with the second trunk has an epitaxial relationship to that trunk. 相似文献
185.
Mandl B Stangl J Mårtensson T Mikkelsen A Eriksson J Karlsson LS Bauer GU Samuelson L Seifert W 《Nano letters》2006,6(8):1817-1821
III-V nanowires have been fabricated by metal-organic vapor-phase epitaxy without using Au or other metal particles as a catalyst. Instead, prior to growth, a thin SiOx layer is deposited on the substrates. Wires form on various III-V substrates as well as on Si. They are nontapered in thickness and exhibit a hexagonal cross-section. From high-resolution X-ray diffraction, the epitaxial relation between wires and substrates is demonstrated and their crystal structure is determined. 相似文献
186.
Electron beam pre-patterning for site-control of self-assembled InAs quantum dots on Inp surfaces 总被引:2,自引:0,他引:2
M. Borgström T. Bryllert B. Gustafson J. Johansson T. Sass L. E. Wernersson W. Seifert L. Samuelson 《Journal of Electronic Materials》2001,30(5):482-486
A site control technique for individual InAs quantum dots (QDs) formed by self-assembling has been developed, using scanning
electron microscope (SEM) assisted nano-deposition and metal organic vapor phase epitaxy (MOVPE). In a first step we characterize
a device with randomly distributed InAs QDs on InP, using resonant tunneling and transmission electron microscopy (TEM). Secondly,
we use nano-scale deposits, created at the focal point of the electron beam on an InP based heterostructure, as “nano growth
masks”. Growth of a thin InP layer produces nano-holes above the deposits. The deposits are removed by oxygen plasma etching.
When InAs is supplied on this surface, QDs are self-assembled at the hole sites, while no InAs dots are observed in the flat
surface region. A vertical single electron tunneling device is proposed, using the developed technique. 相似文献