全文获取类型
收费全文 | 165篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 42篇 |
金属工艺 | 13篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
能源动力 | 21篇 |
轻工业 | 8篇 |
石油天然气 | 2篇 |
无线电 | 37篇 |
一般工业技术 | 22篇 |
冶金工业 | 8篇 |
自动化技术 | 13篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 12篇 |
2012年 | 14篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 15篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有171条查询结果,搜索用时 0 毫秒
21.
Nanoimprint lithography is used to directly pattern the conjugated polymer semiconductor poly(3-hexylthiophene) (P3HT). We obtain trenches with aspect ratios up to 2 and feature sizes as small as 50?nm in this polymer. The application to organic solar cells is shown by creating an interpenetrated donor-acceptor interface, based on P3HT and N,N'-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C(13)), deposited from the vapor phase to reduce shadow effects. A planarizing layer of spin-coated zinc oxide (ZnO) nanoparticles is used to reduce the roughness of the layer stack. The response of the photovoltaic devices follows the increased interface area, up to a 2.5-fold enhancement. 相似文献
22.
L. Stalmans J. Poortmans H. Bender M. Caymax K. Said E. Vazsonyi J. Nijs R. Mertens 《Progress in Photovoltaics: Research and Applications》1998,6(4):233-246
Crystalline silicon (c-Si) is the dominant semiconductor material in use for terrestrial photovoltaic cells and a clear tendency towards thinner, active cell structures and simplified processing schemes is observable within contemporary c-Si photovoltaic research. The potential applications of porous silicon and related benefits are reviewed. Specific attention is given to the different porous silicon formation processes, the use of this porous material as anti-reflection coating in simplified processing schemes and for simple selective emitter processes and its light trapping and surface passivating capabilities, which are required for advantageous use in thin active cell structures. Our analysis of internal quantum efficiency data obtained on both conventional and thin-film c-Si solar cells has been performed with the aim of describing the light diffusing behaviour of porous Si as well as investigating the surface passivating capabilities. An effective entrance angle of 60° is derived, which corresponds to totally diffuse isotropic light, and the importance of a correction for absorption losses in the porous layer is illustrated. Furthermore, photoconductivity decay measurements of freshly etched porous Si on float-zone p-type Si indicate a strong bias-light dependency and a fast degradation of the surface recombination velocity. © 1998 John Wiley & Sons, Ltd. 相似文献
23.
Annabel Braem Tina Mattheys Bram Neirinck Miran Čeh Saša Novak Jan Schrooten Omer Van der Biest Jef Vleugels 《Materials science & engineering. C, Materials for biological applications》2012,32(8):2267-2273
Surface modification of Ti alloys towards an improved osteoinductive behaviour is one of the major challenges in orthopaedic implant technology nowadays. One way to achieve this is by applying a bioactive coating which can increase the rate of osseointegration and chemical bonding of surrounding bone to the implant. In the present work, the production of a bioactive glass–ceramic coating on flat Ti alloys by electrophoretic deposition is demonstrated. The coatings are applied by cathodic deposition from non-aqueous suspensions followed by sintering in vacuum, avoiding uncontrolled oxidation of the Ti substrates. The use of non-aqueous suspensions both allowed to reduce the deposition time and yielded homogeneous coatings with a uniform thickness of 8 μm. Evaluation of the coating adhesion confirmed the good mechanical performance of the coatings with a tensile bond strength of 41.0 ± 11.1 MPa. Additionally, a feasibility study demonstrated the potential of electrophoretic deposition as a coating technique for commercial complex implants. 相似文献
24.
25.
Beverley M. Dancy Dr. Nicholas T. Crump Daniel J. Peterson Dr. Chandrani Mukherjee Dr. Erin M. Bowers Dr. Young‐Hoon Ahn Dr. Minoru Yoshida Dr. Jin Zhang Dr. Louis C. Mahadevan Dr. David J. Meyers Dr. Jef D. Boeke Dr. Philip A. Cole 《Chembiochem : a European journal of chemical biology》2012,13(14):1973-1973
26.
Ji Zou Shui‐Gen Huang Kim Vanmeensel Guo‐Jun Zhang Jef Vleugels Omer Van der Biest 《Journal of the American Ceramic Society》2013,96(4):1055-1059
A carbide boronizing method was first developed to produce dense boron carbide‐ zirconium diboride (“B4C”–ZrB2) composites from zirconium carbide (ZrC) and amorphous boron powders (B) by Spark Plasma Sintering at 1800°C–2000°C. The stoichiometry of “B4C” could be tailored by changing initial boron content, which also has an influence on the processing. The self‐propagating high‐temperature synthesis could be ignited by 1 mol ZrC and 6 mol B at around 1240°C, whereas it was suppressed at a level of 10 mol B. B8C–ZrB2 ceramics sintered at 1800°C with 1 mole ZrC and 10 mole B exhibited super high hardness (40.36 GPa at 2.94 N and 33.4 GPa at 9.8 N). The primary reason for the unusual high hardness of B8C–ZrB2 ceramics was considered to be the formation of nano‐sized ZrB2 grains. 相似文献
27.
28.
Olivier Malek Jef Vleugels Yeczain Perez Patrick De Baets Junhu Liu Sven Van den Berghe Bert Lauwers 《Materials Chemistry and Physics》2010
The interrelationships between the dispersion of the ZrO2 phase and the electrical discharge machining (EDM) behaviour of WC based composites with 0, 5 or 10 vol% of ZrO2 are investigated. Special attention was given to the homogeneity of the ultrafine WC – nanometric ZrO2 powder based composites which were fully densified by means of pulsed electric current sintering (PECS). X-ray photoelectron spectroscopy (XPS) measurements revealed the presence of a nanometric WO3 layer on the EDM surface, confirming oxidation as the major material removal mechanism (MRM). The surface roughness after the final EDM finishing regime was strongly influenced by the composite homogeneity and could be reduced down to 0.15 μm (Ra) on agglomerate-free composites. Residual stress measurements indicated that EDM did not introduce a significant amount of surface stresses, especially not after the final finishing regime. XRD measurements of EDM surfaces however indicated surface depletion of ZrO2 by the formation of ZrC and W2C during spark erosion. 相似文献
29.
Filip Duerinckx Kris Van Nieuwenhuysen Hyonju Kim Izabela Kuzma‐Filipek Harold Dekkers Guy Beaucarne Jef Poortmans 《Progress in Photovoltaics: Research and Applications》2005,13(8):673-690
Thin‐film epitaxial silicon solar cells are an attractive future alternative for bulk silicon solar cells incorporating many of the process advantages of the latter, but on a potentially cheap substrate. Several challenges have to be tackled before this potential can be successfully exploited on a large scale. This paper describes the points of interest and how IMEC aims to solve them. It presents a new step forward towards our final objective: the development of an industrial cell process based on screen‐printing for > 15% efficient epitaxial silicon solar cells on a low‐cost substrate. Included in the discussion are the substrates onto which the epitaxial deposition is done and how work is progressing in several research institutes and universities on the topic of a high‐throughput epitaxial reactor. The industrial screen‐printing process sequence developed at IMEC for these epitaxial silicon solar cells is presented, with emphasis on plasma texturing and improvement of the quality of the epitaxial layer. Efficiencies between 12 and 13% are presented for large‐area (98 cm2) epitaxial layers on highly doped UMG‐Si, off‐spec and reclaim material. Finally, the need for an internal reflection scheme is explained. A realistically achievable internal reflection at the epi/substrate interface of 70% will result in a calculated increase of 3 mA/cm2 in short‐circuit current. An interfacial stack of porous silicon layers (Bragg reflectors) is chosen as a promising candidate and the challenges facing its incorporation between the epitaxial layer and the substrate are presented. Experimental work on this topic is reported and concentrates on the extraction of the internal reflection at the epi/substrate interface from reflectance measurements. Initial results show an internal reflectance between 30 and 60% with a four‐layer porous silicon stack. Resistance measurements for majority carrier flow through these porous silicon stacks are also included and show that no resistance increase is measurable for stacks up to four layers. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
30.
R. Bilyalov L. Stalmans G. Beaucarne R. Loo M. Caymax J. Poortmans J. Nijs 《Solar Energy Materials & Solar Cells》2001,65(1-4)
The potential of porous silicon (PS) with dual porosity structure as an intermediate layer for ultra-thin film solar cells is described. It is shown that a double-layered PS with a porosity of
% allows to grow epitaxial Si film at medium temperature (725°–800°C) and at the same time serves as a gettering/diffusion barrier for impurities from potentially contaminated low-cost substrate. A 3.5 μm thin-film cell with reasonable efficiency is realized using such a PS intermediate layer. 相似文献