全文获取类型
收费全文 | 227篇 |
免费 | 54篇 |
国内免费 | 22篇 |
专业分类
电工技术 | 28篇 |
综合类 | 6篇 |
化学工业 | 33篇 |
金属工艺 | 10篇 |
机械仪表 | 5篇 |
能源动力 | 3篇 |
轻工业 | 1篇 |
无线电 | 104篇 |
一般工业技术 | 103篇 |
冶金工业 | 4篇 |
自动化技术 | 6篇 |
出版年
2023年 | 9篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 14篇 |
2019年 | 25篇 |
2018年 | 14篇 |
2017年 | 18篇 |
2016年 | 16篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 6篇 |
2012年 | 19篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 19篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 11篇 |
2005年 | 15篇 |
2004年 | 4篇 |
2003年 | 15篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
排序方式: 共有303条查询结果,搜索用时 0 毫秒
301.
Eric C. Wu Charlene Z. Salamat Omar León Ruiz Thomas Qu Alexis Kim Sarah H. Tolbert Benjamin J. Schwartz 《Advanced functional materials》2023,33(19):2213652
When an electron is removed from a conjugated polymer, such as poly(3-hexylthiophene-2,5-diyl) (P3HT), the remaining hole and associated change in the polymer backbone structure from aromatic to quinoidal are referred to as a polaron. Bipolarons are created by removing the unpaired electron from an already-oxidized polymer segment. In electrochemically-doped P3HT films, polarons, and bipolarons are readily observed, but in chemically-doped P3HT films, bipolarons rarely form. This is explained by studying the effects of counterion position on the formation of polarons, strongly coupled polarons, and bipolarons using both spectroscopic and X-ray diffraction experiments and time-dependent density functional theory calculations. The counterion positions control whether two polarons spin-pair to form a bipolaron or whether they strongly couple without spin-pairing are found. When two counterions lie close to the same polymer segment, bipolarons can form, with an absorption spectrum that is blueshifted from that of a single polaron. Otherwise, polarons at high concentrations do not spin-pair, but instead J-couple, leading to a redshifted absorption spectrum. The counterion location needed for bipolaron formation is accompanied by a loss of polymer crystallinity. These results explain the observed formation order of single polarons, coupled single polarons, and singlet bipolarons in electrochemically- and chemically-doped conjugated polymers. 相似文献
302.
Piero Mazzolini Zsolt Fogarassy Antonella Parisini Francesco Mezzadri David Diercks Matteo Bosi Luca Seravalli Anna Sacchi Giulia Spaggiari Danilo Bersani Oliver Bierwagen Benjamin Moritz Janzen Marcella Naomi Marggraf Markus R. Wagner Ildiko Cora Béla Pécz Abbes Tahraoui Alessio Bosio Carmine Borelli Stefano Leone Roberto Fornari 《Advanced functional materials》2023,33(2):2207821
Unintentionally doped (001)-oriented orthorhombic κ-Ga2O3 epitaxial films on c-plane sapphire substrates are characterized by the presence of ≈ 10 nm wide columnar rotational domains that can severely inhibit in-plane electronic conduction. Comparing the in- and out-of-plane resistance on well-defined sample geometries, it is experimentally proved that the in-plane resistivity is at least ten times higher than the out-of-plane one. The introduction of silane during metal-organic vapor phase epitaxial growth not only allows for n-type Si extrinsic doping, but also results in the increase of more than one order of magnitude in the domain size (up to ≈ 300 nm) and mobility (highest µ ≈ 10 cm2V−1s−1, with corresponding lowest ρ ≈ 0.2 Ωcm). To qualitatively compare the mean domain dimension in κ-Ga2O3 epitaxial films, non-destructive experimental procedures are provided based on X-ray diffraction and Raman spectroscopy. The results of this study pave the way to significantly improved in-plane conduction in κ-Ga2O3 and its possible breakthrough in new generation electronics. The set of cross-linked experimental techniques and corresponding interpretation here proposed can apply to a wide range of material systems that suffer/benefit from domain-related functional properties. 相似文献
303.
Henok Getachew Girma Kwang Hun Park Dongseob Ji Yejin Kim Hye Min Lee Seungju Jeon Seo-Hyun Jung Jin Young Kim Yong-Young Noh Bogyu Lim 《Advanced functional materials》2023,33(18):2213381
Although semiconducting single-walled carbon nanotubes (sc-SWNTs) exhibit excellent sensing properties for various gases, commercialization is hampered by several obstacles. Among these, the difficulty in reproducibly fabricating sc-SWNT films with uniform density and thickness is the main one. Here, a facile fabrication method for sc-SWNT-based hydrogen (H2) sensors with excellent reproducibility, high sensitivity, and selectivity against CO, CO2, and CH4 is reported. Uniform-density and monolayer sc-SWNT films are fabricated using chemical immobilized through the click reaction between azide-functionalized polymer-wrapped sc-SWNTs and immobilized alkyne polymer on a substrate before decorating with Pd nanoparticles (0.5–3.0 nm). The optimized sc-SWNT sensor has a high room-temperature response of 285 with the response and recovery times of 10 and 3 s, respectively, under 1% H2 gas in air. In particular, this sensor demonstrates highly selective H2 detection at room temperature (25 °C), compared to other gases and humidity. Therefore, the chemical immobilization of the monolayer SWNT films with reproducible and uniform density has the potential for large-scale fabrication of robust room-temperature H2 sensors. 相似文献