全文获取类型
收费全文 | 3749篇 |
免费 | 280篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 44篇 |
综合类 | 5篇 |
化学工业 | 868篇 |
金属工艺 | 72篇 |
机械仪表 | 55篇 |
建筑科学 | 161篇 |
矿业工程 | 5篇 |
能源动力 | 142篇 |
轻工业 | 264篇 |
水利工程 | 34篇 |
石油天然气 | 15篇 |
无线电 | 297篇 |
一般工业技术 | 794篇 |
冶金工业 | 617篇 |
原子能技术 | 26篇 |
自动化技术 | 634篇 |
出版年
2023年 | 55篇 |
2022年 | 86篇 |
2021年 | 168篇 |
2020年 | 116篇 |
2019年 | 114篇 |
2018年 | 140篇 |
2017年 | 126篇 |
2016年 | 138篇 |
2015年 | 116篇 |
2014年 | 187篇 |
2013年 | 261篇 |
2012年 | 228篇 |
2011年 | 292篇 |
2010年 | 194篇 |
2009年 | 179篇 |
2008年 | 186篇 |
2007年 | 170篇 |
2006年 | 149篇 |
2005年 | 94篇 |
2004年 | 107篇 |
2003年 | 69篇 |
2002年 | 78篇 |
2001年 | 32篇 |
2000年 | 26篇 |
1999年 | 44篇 |
1998年 | 63篇 |
1997年 | 46篇 |
1996年 | 32篇 |
1995年 | 38篇 |
1994年 | 27篇 |
1993年 | 25篇 |
1992年 | 17篇 |
1990年 | 20篇 |
1989年 | 17篇 |
1988年 | 12篇 |
1987年 | 12篇 |
1985年 | 23篇 |
1984年 | 19篇 |
1983年 | 17篇 |
1982年 | 22篇 |
1981年 | 26篇 |
1980年 | 13篇 |
1979年 | 26篇 |
1978年 | 19篇 |
1977年 | 17篇 |
1976年 | 24篇 |
1975年 | 18篇 |
1974年 | 18篇 |
1972年 | 11篇 |
1971年 | 12篇 |
排序方式: 共有4033条查询结果,搜索用时 187 毫秒
91.
Thomas F. O'Dwyer Benjamin K. Hodnett 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,62(1):30-37
Adsorption isotherms for sodium and trivalent chromium uptake from aqueous solutions onto Amberlite resin were prepared at 18°C. Adsorption of each cation followed the Langmuir model. The rate of uptake of each cation was found to be film diffusion controlled with sodium showing the most rapid uptake. In aqueous solutions containing both chromium and sodium as the only cationic species, it was found that with increasing initial concentration of sodium, the trivalent chromium uptake on the resin decreased substantially. To overcome this difficulty a four step redox–adsorption system has been developed for the removal of Cr3+ from tannery effluents. The first step comprises the oxidation of trivalent chromium to the hexavalent form using selected common oxidising agents. The liquid effluent is then passed through an Amberlite cation-exchange resin in step 2 where the sodium in the waste stream is completely removed. The anionic hexavalent form of chromium (Cr2O) passes unaltered through the resin along with the waste stream. In the third stage the dichromate is reduced back to the trivalent cationic form which is subsequently removed from the waste stream by a second Amberlite ion-exchange bed in stage 4. Each step in this process is assessed in batch and flow mode using simulated and real tannery effluents. 相似文献
92.
Lin Pei-Chun Yankson Benjamin Chauhan Vishal Tsukada Manabu 《The Journal of supercomputing》2022,78(13):15060-15088
The Journal of Supercomputing - Currently, many smart speakers, even social robots, appear on the market to help people's lives become more convenient. Usually, people use smart speakers to... 相似文献
93.
Optimized Photoinitiator for Fast Two‐Photon Absorption Polymerization of Polyester‐Macromers for Tissue Engineering
下载免费PDF全文
![点击此处可从《Advanced Engineering Materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
94.
The Influence of Block Ionomer Microstructure on Polyplex Properties: Can Simulations Help to Understand Differences in Transfection Efficiency?
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
95.
Manipulating Electrical and Fluidic Access in Integrated Nanopore‐Microfluidic Arrays Using Microvalves
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
96.
High Figure of Merit (FOM) of Bragg Modes in Au‐Coated Nanodisk Arrays for Plasmonic Sensing
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Maxime Couture Thibault Brulé Stacey Laing Wenli Cui Mitradeep Sarkar Benjamin Charron Karen Faulds Wei Peng Michael Canva Jean‐Francois Masson 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(38)
Gold‐coated nanodisk arrays of nearly micron periodicity are reported that have high figure of merit (FOM) and sensitivity necessary for plasmonic refractometric sensing, with the added benefit of suitability for surface‐enhanced Raman scattering (SERS), large‐scale microfabrication using standard photolithographic techniques and a simple instrumental setup. Gold nanodisk arrays are covered with a gold layer to excite the Bragg modes (BM), which are the propagative surface plasmons localized by the diffraction from the disk array. This generates surface‐guided modes, localized as standing waves, leading to highly confined fields confirmed by a mapping of the SERS intensity and numerical simulations with 3D finite element method. The optimal gold‐coated nanodisk arrays are applied for refractometric sensing in transmission spectroscopy with better performance than nanohole arrays and they are integrated to a 96‐well plate reader for detection of IgY proteins in the nanometer range in PBS. The potential for sensing in biofluids is assessed with IgG detection in 1:1 diluted urine. The structure exhibits a high FOM of up to 46, exceeding the FOM of structures supporting surface plasmon polaritons and comparable to more complex nanostructures, demonstrating that subwavelength features are not necessary for high‐performance plasmonic sensing. 相似文献
97.
98.
Bioinspired Nacre‐Like Ceramic with Nickel Inclusions Fabricated by Electroless Plating and Spark Plasma Sintering
下载免费PDF全文
![点击此处可从《Advanced Engineering Materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Zhe Xu Jiacheng Huang Cheng Zhang Soheil Daryadel Ali Behroozfar Brandon McWilliams Benjamin Boesl Arvind Agarwal Majid Minary‐Jolandan 《Advanced Engineering Materials》2018,20(5)
99.
Antony Jan Benjamin A. Reeves Yoeri van de Burgt Garrett J. Hayes Bruce M. Clemens 《Advanced Engineering Materials》2018,20(1)
100.
Romain Carron Enrico Avancini Thomas Feurer Benjamin Bissig Paolo A. Losio Renato Figi 《Science and Technology of Advanced Materials》2018,19(1):396-410
Cu(In,Ga)Se2-based solar cells have reached efficiencies close to 23%. Further knowledge-driven improvements require accurate determination of the material properties. Here, we present refractive indices for all layers in Cu(In,Ga)Se2 solar cells with high efficiency. The optical bandgap of Cu(In,Ga)Se2 does not depend on the Cu content in the explored composition range, while the absorption coefficient value is primarily determined by the Cu content. An expression for the absorption spectrum is proposed, with Ga and Cu compositions as parameters. This set of parameters allows accurate device simulations to understand remaining absorption and carrier collection losses and develop strategies to improve performances. 相似文献