全文获取类型
收费全文 | 227篇 |
免费 | 54篇 |
国内免费 | 24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 | 106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 | 10篇 |
2022年 | 4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305条查询结果,搜索用时 15 毫秒
131.
132.
Rational Design of High‐Mobility Semicrystalline Conjugated Polymers with Tunable Charge Polarity: Beyond Benzobisthiadiazole‐Based Polymers
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yang Wang Tsukasa Hasegawa Hidetoshi Matsumoto Takehiko Mori Tsuyoshi Michinobu 《Advanced functional materials》2017,27(2)
High‐mobility semiconducting polymers composed of arylene vinylene and dithiophene‐thiadiazolobenzotriazole (SN) units are developed by three powerful design strategies, namely, backbone engineering, heteroatom substitution, and side‐chain engineering. First, starting from the quaterthiophene‐SN copolymer, a vinylene spacer is inserted into the quaterthiophene unit for constructing highly‐planar backbones. Second, heteroatoms (O and N atoms) are incorporated into the thienylene vinylene moieties to tune the electronic properties and intermolecular interactions. Third, the alkyl side chains are optimized to tune the solubility and self‐assembly properties. As a consequence, a remarkable thin film transistor performance is obtained. The very high hole mobility of 3.22 cm2 V?1 s?1 is achieved for the p‐type polymer, PSNVT‐DTC8, which is the highest value ever reported for the polymers based on the benzobisthiadiazole and its analogs. Moreover, heteroatom substitution efficiently varies the charge polarity of the polymers as in the case of the N atom substituted PSNVTz‐DTC16 displaying n‐type dominant ambipolar properties with the electron mobility of 0.16 cm2 V?1 s?1. Further studies using grazing‐incidence wide‐angle X‐ray scattering and atomic force microscopy have revealed the high crystallinities of the polymer thin films with strong π–π interactions and suitable polymer packing orientations. 相似文献
133.
Tianqi Niu Jing Lu Rahim Munir Jianbo Li Dounya Barrit Xu Zhang Hanlin Hu Zhou Yang Aram Amassian Kui Zhao Shengzhong Liu 《Advanced materials (Deerfield Beach, Fla.)》2018,30(16)
The trap states at grain boundaries (GBs) within polycrystalline perovskite films deteriorate their optoelectronic properties, making GB engineering particularly important for stable high‐performance optoelectronic devices. It is demonstrated that trap states within bulk films can be effectively passivated by semiconducting molecules with Lewis acid or base functional groups. The perovskite crystallization kinetics are studied using in situ synchrotron‐based grazing‐incidence X‐ray scattering to explore the film formation mechanism. A model of the passivation mechanism is proposed to understand how the molecules simultaneously passivate the Pb–I antisite defects and vacancies created by under‐coordinated Pb atoms. In addition, it also explains how the energy offset between the semiconducting molecules and the perovskite influences trap states and intergrain carrier transport. The superior optoelectronic properties are attained by optimizing the molecular passivation treatments. These benefits are translated into significant enhancements of the power conversion efficiencies to 19.3%, as well as improved environmental and thermal stability of solar cells. The passivated devices without encapsulation degrade only by ≈13% after 40 d of exposure in 50% relative humidity at room temperature, and only ≈10% after 24 h at 80 °C in controlled environment. 相似文献
134.
Hui‐Jun Li Darui Zhang Hongwu Wang Zhenlu Chen Nanquan Ou Ping Wang Ding Wang Xianying Wang Junhe Yang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(3)
A large potential can be generated when one end of 1D and/or 2D semiconducting nanostructures such as zinc oxide (ZnO) and molybdenum disulfide is exposed to a wide spectrum of chemical molecules. A nanoenergy generator that comprises vertically aligned ZnO nanowires and poly(vinyl chloride‐co‐vinyl‐co‐2‐hydroxypropyl acrylate) is fabricated, and it can generate electricity from various molecules including gaseous species exhaled from human breath. The generated voltage, which depends sensitively on the molecular dipole moment of adsorbed chemical species and surface coverage, is significantly larger than the streaming or piezoelectric potentials and is powerful enough to directly drive a single carbon nanotube field‐effect transistor. It is demonstrated that the notion of voltage generation through molecule‐surface interactions bears general implications to other semiconducting materials, and has the advantages of simplicity, cost‐effectiveness, fast response to a wide range of molecules, and high power output, making our approach a promising tool for energy conversion and sensing applications. 相似文献
135.
Song Qiu Kunjie Wu Bing Gao Liqiang Li Hehua Jin Qingwen Li 《Advanced materials (Deerfield Beach, Fla.)》2019,31(9)
High‐purity semiconducting single‐walled carbon nanotubes (s‐SWCNTs) are of paramount significance for the construction of next‐generation electronics. Until now, a number of elaborate sorting and purification techniques for s‐SWCNTs have been developed, among which solution‐based sorting methods show unique merits in the scale production, high purity, and large‐area film formation. Here, the recent progress in the solution processing of s‐SWCNTs and their application in electronic devices is systematically reviewed. First, the solution‐based sorting and purification of s‐SWCNTs are described, and particular attention is paid to the recent advance in the conjugated polymer‐based sorting strategy. Subsequently, the solution‐based deposition and morphology control of a s‐SWCNT thin film on a surface are introduced, which focus on the strategies for network formation and alignment of SWCNTs. Then, the recent advances in electronic devices based on s‐SWCNTs are reviewed with emphasis on nanoscale s‐SWCNTs' high‐performance integrated circuits and s‐SWCNT‐based thin‐film transistors (TFT) array and circuits. Lastly, the existing challenges and development trends for the s‐SWCNTs and electronic devices are briefly discussed. The aim is to provide some useful information and inspiration for the sorting and purification of s‐SWCNTs, as well as the construction of electronic devices with s‐SWCNTs. 相似文献
136.
Taylor J. Aubry Jonathan C. Axtell Victoria M. Basile K. J. Winchell Jeffrey R. Lindemuth Tyler M. Porter Ji‐Yuan Liu Anastassia N. Alexandrova Clifford P. Kubiak Sarah H. Tolbert Alexander M. Spokoyny Benjamin J. Schwartz 《Advanced materials (Deerfield Beach, Fla.)》2019,31(11)
One of the most effective ways to tune the electronic properties of conjugated polymers is to dope them with small‐molecule oxidizing agents, creating holes on the polymer and molecular anions. Undesirably, strong electrostatic attraction from the anions of most dopants localizes the holes created on the polymer, reducing their mobility. Here, a new strategy utilizing a substituted boron cluster as a molecular dopant for conjugated polymers is employed. By designing the cluster to have a high redox potential and steric protection of the core‐localized electron density, highly delocalized polarons with mobilities equivalent to films doped with no anions present are obtained. AC Hall effect measurements show that P3HT films doped with these boron clusters have conductivities and polaron mobilities roughly an order of magnitude higher than films doped with F4TCNQ, even though the boron‐cluster‐doped films have poor crystallinity. Moreover, the number of free carriers approximately matches the number of boron clusters, yielding a doping efficiency of ≈100%. These results suggest that shielding the polaron from the anion is a critically important aspect for producing high carrier mobility, and that the high polymer crystallinity required with dopants such as F4TCNQ is primarily to keep the counterions far from the polymer backbone. 相似文献
137.
Zhenjie Ni Hanlin Wang Qiang Zhao Jianqi Zhang Zhixiang Wei Huanli Dong Wenping Hu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(10)
High mobility ambipolar conjugated polymers are seriously absent regardless their great potential for flexible and printed plastic devices and circuits. Here, ambipolar polymers with ultrahigh balanced hole and electron mobility are developed via a two‐step C? H activation strategy. Diketopyrrolopyrrole‐benzothiadiazole‐diketopyrrolopyrrole (DBD) and its copolymers with thiophene/selenophene units (short as PDBD‐T and PDBD‐Se) are used as examples. PDBD‐Se exhibits highly efficient ambipolar transport with hole and electron mobility up to 8.90 and 7.71 cm2 V?1 s?1 in flexible organic field‐effect transistors, presenting a milestone for ambipolar copolymer screening. Based on this performance metrics and good solubility, PDBD‐Se is investigated as inkjet‐printable semiconductor ink for organic complementary logic circuits. Under ambient processing, maximum hole and electron mobilities reach 6.70 and 4.30 cm2 V?1 s?1, respectively. Printed complementary inverter and NAND gates with transition voltages near VDD/2 are fabricated, providing an easy‐handling, general material for printed electronics and logic. 相似文献
138.
Wen Zhou Ying Chen Yutao Zhang Xiaoyan Xin Rutian Li Chen Xie Quli Fan 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(5)
Photodynamic therapy (PDT) is a promising technique for cancer therapy, providing good therapeutic efficacy with minimized side effect. However, the lack of oxygen supply in the hypoxic tumor site obviously restricts the generation of singlet oxygen (1O2), thus limiting the efficacy of PDT. So far, the strategies to improve PDT efficacy usually rely on complicated nanosystems, which require sophisticated design or complex synthetic procedure. Herein, iodine‐rich semiconducting polymer nanoparticles (SPN‐I) for enhanced PDT, using iodine‐induced intermolecular heavy‐atom effect to elevate the 1O2 generation, are designed and prepared. The nanoparticles are composed of a near‐infrared (NIR) absorbing semiconducting polymer (PCPDTBT) serving as the photosensitizer and source of fluorescence signal, and an iodine‐grafted amphiphilic diblock copolymer (PEG‐PHEMA‐I) serving as the 1O2 generation enhancer and nanocarrier. Compared with SPN composed of PEG‐b‐PPG‐b‐PEG and PCPDTBT (SPN‐P), SPN‐I can enhance the 1O2 generation by 1.5‐fold. In addition, SPN‐I have high X‐ray attenuation coefficient because of the high density of iodine in PEG‐PHEMA‐I, providing SPN‐I the ability of use with computed tomography (CT) and fluorescence dual‐modal imaging. The study thus provides a simple nanotheranostic platform composed of two components for efficient CT/fluorescence dual‐modal imaging‐guided enhanced PDT. 相似文献
139.
采用极化曲线、电化学阻抗谱(EIS)和电位电容法,在静态和超声波空化的条件下,研究了不锈钢在1 mol/L HCl溶液中的电化学腐蚀行为.结果表明,静态条件下,0Cr13Ni5Mo和1Cr18Ni9Ti不锈钢均发生了钝化,钝化膜呈多层结构分布;空化条件下,钝化膜的稳定性降低,半导特性发生反转.静态条件下,0Cr13Ni5Mo不锈钢钝化膜的半导特性是p-型;空化使半导特性转变为n-型.静态条件下,在低电位区1Cr18Ni9Ti不锈钢钝化膜的半导特性是n-型,在高电位区是p-型;空化条件下,在低电位区1Cr18Ni9Ti不锈钢钝化膜半导特性显示p-型,在高电位区显示n-型.钝化膜半导性质转变的差异与其Fermi能级的高低相关. 相似文献
140.
采用光电化学方法研究了304不锈钢载波钝化膜在硼酸/硼砂溶液中的光电化学性质.通过测量钝化膜的光电流与入射光光子能量的关系和光电流与测量电位的关系,结合半导体理论.对载波钝化膜的半导体特性和结构进行了分析.结果表明,载波钝化膜是一高度无序的非晶态半导体膜且具有P型半导体特性.膜层的光电流对测量电位的响应在一定范围内符合Poole-Frenkel效应,但在其它范围内则具有一定的复杂性. 相似文献