全文获取类型
收费全文 | 521篇 |
免费 | 30篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 97篇 |
金属工艺 | 13篇 |
机械仪表 | 23篇 |
建筑科学 | 5篇 |
矿业工程 | 1篇 |
能源动力 | 10篇 |
轻工业 | 19篇 |
水利工程 | 27篇 |
石油天然气 | 8篇 |
无线电 | 49篇 |
一般工业技术 | 168篇 |
冶金工业 | 60篇 |
原子能技术 | 11篇 |
自动化技术 | 57篇 |
出版年
2023年 | 6篇 |
2022年 | 14篇 |
2021年 | 22篇 |
2020年 | 10篇 |
2019年 | 9篇 |
2018年 | 23篇 |
2017年 | 17篇 |
2016年 | 21篇 |
2015年 | 20篇 |
2014年 | 22篇 |
2013年 | 37篇 |
2012年 | 35篇 |
2011年 | 30篇 |
2010年 | 29篇 |
2009年 | 18篇 |
2008年 | 25篇 |
2007年 | 17篇 |
2006年 | 13篇 |
2005年 | 19篇 |
2004年 | 14篇 |
2003年 | 9篇 |
2002年 | 12篇 |
2001年 | 14篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 7篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有551条查询结果,搜索用时 31 毫秒
101.
Suturin SM Sokolov NS Banshchikov AG Kyutt RN Sakata O Shimura T Harada J Tabuchi M Takeda Y 《Journal of nanoscience and nanotechnology》2011,11(4):2990-2996
Surface X-ray diffraction was applied to study structure of the fluorite-silicon interface forming upon epitaxial growth of CaF2 on Si(001) surface kept at 750 degrees C. Samples with CaF2 coverage of 1.5-4 (110)-monolayers were grown and in-situ characterized using synchrotron radiation. The 3 x 1-like surface reconstruction was observed in agreement with the previous studies by electron diffraction. Interestingly, a well pronounced splitting of the fractional x 1/3 reflections was revealed. This splitting was ascribed to the effect of antiphase domain boundaries in the row-like structure of the interface layer. The in-plane integrated intensities were used to reconstruct two-dimensional atomic structure of the high-temperature CaF2/Si(001) interface. 相似文献
102.
103.
104.
A. L. Gavrik Yu. A. Gavrik T. F. Kopnina E. A. Kuleshov 《Journal of Communications Technology and Electronics》2013,58(10):985-995
The possibility of detecting wave processes in the atmosphere-ionosphere system of the planet from perturbations of radio signals in radio occultation experiments is studied. A method of interpretation of the radio-raying data that does not employ integral transforms and is well-adapted to problems of detecting refractive index oscillations observed during sensing of the stratified gas envelope of the planet is presented. Periodic oscillations of the radio signal power that are linearly related with the rate of variation in the frequency of the signal used for probing of the atmosphere and ionosphere are found, which evidences wave perturbations of the medium near the lower boundary of the daytime ionosphere of Venus. 相似文献
105.
106.
Potential release pathways, environmental fate, and ecological risks of carbon nanotubes 总被引:1,自引:0,他引:1
Petersen EJ Zhang L Mattison NT O'Carroll DM Whelton AJ Uddin N Nguyen T Huang Q Henry TB Holbrook RD Chen KL 《Environmental science & technology》2011,45(23):9837-9856
Carbon nanotubes (CNTs) are currently incorporated into various consumer products, and numerous new applications and products containing CNTs are expected in the future. The potential for negative effects caused by CNT release into the environment is a prominent concern and numerous research projects have investigated possible environmental release pathways, fate, and toxicity. However, this expanding body of literature has not yet been systematically reviewed. Our objective is to critically review this literature to identify emerging trends as well as persistent knowledge gaps on these topics. Specifically, we examine the release of CNTs from polymeric products, removal in wastewater treatment systems, transport through surface and subsurface media, aggregation behaviors, interactions with soil and sediment particles, potential transformations and degradation, and their potential ecotoxicity in soil, sediment, and aquatic ecosystems. One major limitation in the current literature is quantifying CNT masses in relevant media (polymers, tissues, soils, and sediments). Important new directions include developing mechanistic models for CNT release from composites and understanding CNT transport in more complex and environmentally realistic systems such as heteroaggregation with natural colloids and transport of nanoparticles in a range of soils. 相似文献
107.
Nikolai B. Gorev Inna F. Kodzhespirova Yury A. Kovalenko Evgeny N. Privalov Eugenio F. Prokhorov 《Microelectronics Journal》2001,32(12):979-982
The distribution of the electric field in planar film–substrate GaAs structures under backgating is considered. It is shown that backgating can make the film exhibit a long-length region of a low-gradient electric field exceeding the threshold of N-type negative differential mobility, the magnitude of negative differential mobility in this region being high enough. At values of the film doping density and film thickness typical of GaAs transferred-electron devices, this region can be as long as several tens of micrometers. The underlying physical mechanism is discussed. 相似文献
108.
Gregory Ya. Slepyan Nikolai A. Krapivin Sergey A. Maksimenko Akhlesh Lakhtakia Oleg M. Yevtushenko 《AEUE-International Journal of Electronics and Communications》2001,55(4):273-280
Scattering of electromagnetic cylindrical waves by an isolated, semi-infinite, open-ended, single-shell, zigzag carbon nanotube (CN) is considered in the optical regime. The CN is modeled as a smooth homogeneous cylindrical surface with impedance boundary conditions known from quantum-mechanical transport theory. An exact solution of the diffraction problem is obtained by the Wiener-Hopf technique. The differences between the scattering responses of metallic and semiconducting CNs are discussed. 相似文献
109.
Vadim E. Filatov Dmitrii A. Iuzabchuk Viktor A. Tafeenko Yuri K. Grishin Vitaly A. Roznyatovsky Dmitrii A. Lukianov Yulia A. Fedotova Maxim A. Sukonnikov Dmitry A. Skvortsov Nikolai V. Zyk Elena K. Beloglazkina 《International journal of molecular sciences》2022,23(12)
In this work, we present the first synthesis of dispirooxindole-β-lactams employing optimized methodology of one-pot Staudinger ketene-imine cycloaddition with N-aryl-2-oxo-pyrrolidine-3-carboxylic acids as the ketene source. Spiroconjugation of indoline-2-one with β-lactams ring is considered to be able to provide stabilization and wide scope of functionalization to resulting scaffolds. The dispipooxindoles obtained demonstrated medium cytotoxicity in the MTT test on A549, MCF7, HEK293, and VA13 cell lines, and one of the compounds demonstrated antibacterial activity against E. coli strain LPTD. 相似文献
110.
Chloride and Indium‐Chloride‐Complex Inorganic Ligands for Efficient Stabilization of Nanocrystals in Solution and Doping of Nanocrystal Solids
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)
Vladimir Sayevich Chris Guhrenz Maria Sin Volodymyr M. Dzhagan Alexander Weiz Daniel Kasemann Eike Brunner Michael Ruck Dietrich R. T. Zahn Karl Leo Nikolai Gaponik Alexander Eychmüller 《Advanced functional materials》2016,26(13):2163-2175
Here, the surface functionalization of CdSe and CdSe/CdS core/shell nanocrystals (NCs) with compact chloride and indium‐chloride‐complex ligands is reported. The ligands provide not only short interparticle distances but additionally control doping and passivation of surface trap states, leading to enhanced electronic coupling in NC‐based arrays. The solids based on these NCs show an excellent electronic transport behavior after heat treatment at the relatively low temperature of 190 °C. Indeed, the indium‐chlorido‐capped 4.5 nm CdSe NC based thin‐film field‐effect transistor reaches a saturation mobility of μ = 4.1 cm2 (V s)?1 accompanied by a low hysteresis, while retaining the typical features of strongly quantum confined semiconductor NCs. The capping with chloride ions preserves the high photoluminescence quantum yield ( ≈ 66%) of CdSe/CdS core/shell NCs even when the CdS shell is relatively thin (six monolayers). The simplicity of the chemical incorporation of chlorine and indium species via solution ligand exchange, the efficient electronic passivation of the NC surface, as well as their high stability as dispersions make these materials especially attractive for wide‐area solution‐processable fabrication of NC‐based devices. 相似文献