全文获取类型
收费全文 | 2803篇 |
免费 | 296篇 |
国内免费 | 89篇 |
专业分类
电工技术 | 221篇 |
综合类 | 145篇 |
化学工业 | 351篇 |
金属工艺 | 417篇 |
机械仪表 | 128篇 |
建筑科学 | 88篇 |
矿业工程 | 46篇 |
能源动力 | 55篇 |
轻工业 | 155篇 |
水利工程 | 45篇 |
石油天然气 | 114篇 |
武器工业 | 22篇 |
无线电 | 257篇 |
一般工业技术 | 250篇 |
冶金工业 | 177篇 |
原子能技术 | 86篇 |
自动化技术 | 631篇 |
出版年
2024年 | 9篇 |
2023年 | 24篇 |
2022年 | 61篇 |
2021年 | 77篇 |
2020年 | 59篇 |
2019年 | 249篇 |
2018年 | 155篇 |
2017年 | 98篇 |
2016年 | 110篇 |
2015年 | 129篇 |
2014年 | 163篇 |
2013年 | 232篇 |
2012年 | 206篇 |
2011年 | 204篇 |
2010年 | 159篇 |
2009年 | 165篇 |
2008年 | 110篇 |
2007年 | 154篇 |
2006年 | 130篇 |
2005年 | 100篇 |
2004年 | 58篇 |
2003年 | 47篇 |
2002年 | 31篇 |
2001年 | 212篇 |
2000年 | 59篇 |
1999年 | 22篇 |
1998年 | 30篇 |
1997年 | 24篇 |
1996年 | 27篇 |
1995年 | 15篇 |
1994年 | 21篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 1篇 |
排序方式: 共有3188条查询结果,搜索用时 15 毫秒
1.
Md. Abdur Rahim Shamim Mahbub Md. Kamrul Islam Sk. Md. Ali Ahsan Shahed Rana Malik Abdul Rub Anish Khan Md. Anamul Hoque 《Journal of surfactants and detergents》2020,23(2):457-470
Conductometric and cloud point (CP) measurement studies have been performed to investigate the interaction of tetradecyltrimethylammonium bromide (TTAB) and Triton® X-100 (TX-100) with ciprofloxacin hydrochloride (CFH) in different solvents over the temperature range of 295.15–315.15 K. CFH is used for the treatment of various bacterial infections. The observed critical micelle concentration (CMC) values of TTAB were found to be reduced in the presence of electrolytes (Na2SO4/Na3PO4), and this reduction proceeds with the elevation of salt concentration. The order of the CMC of TTAB follows the trend: > >. The observed CMC values of TTAB were found to increase with increasing temperature and decrease with increasing concentration of CFH in aqueous medium. The values of Gibbs free energy of micellization () for the TTAB/TTAB + CFH mixture were found to be negative, implying spontaneous micellization. The estimated CP of TX-100 decreases with increasing concentration of TX-100 in aqueous medium. The CP values first decrease with increasing concentration of CFH and then increase at higher concentration of CFH almost in all cases investigated. The values of free energy of clouding were found to be positive in all cases studied implying that phase separation of TX-100 was nonspontaneous. The other thermodynamic parameters associated with the micellization of TTAB and the phase separation of TX-100 were estimated and explained. 相似文献
2.
Jinho Choi Sanghun Jung Deok Gun Park Jaegul Choo Niklas Elmqvist 《Computer Graphics Forum》2019,38(3):249-260
The majority of visualizations on the web are still stored as raster images, making them inaccessible to visually impaired users. We propose a deep‐neural‐network‐based approach that automatically recognizes key elements in a visualization, including a visualization type, graphical elements, labels, legends, and most importantly, the original data conveyed in the visualization. We leverage such extracted information to provide visually impaired people with the reading of the extracted information. Based on interviews with visually impaired users, we built a Google Chrome extension designed to work with screen reader software to automatically decode charts on a webpage using our pipeline. We compared the performance of the back‐end algorithm with existing methods and evaluated the utility using qualitative feedback from visually impaired users. 相似文献
3.
Daniela M. Nevskaia Maria Luisa Rojas Cervantes Antonio Guerrero Ruíz Juan de Dios Lpez Gonzlez 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,63(3):249-256
Adsorption of Triton X-100 on various silica substrates has been investigated. A number of solids, including a natural quartz, this quartz washed with HCl acid and subsequently heated at 1273 K; two aerosils and one Kieselgel silicas were studied. These solids exhibit surface areas in the range of 5 to 430 m2 g?1. All the Triton adsorption isotherms display an S-shape at the adsorption temperatures studied (298 and 308 K). It has been found that the pretreatments of natural quartz (by water washing, impurities removed by acid and/or high temperature calcination) affect considerably the amounts of TX-100 adsorbed. Measurements of surface composition have been made by X-ray photoelectron spectroscopy (XPS) with particular emphasis on the presence of impurities and on the number of OH groups at the surface of the samples. The nature of the surface hydroxyl has also been studied by infrared spectroscopy. Furthermore, the specific number of hydroxyl groups on the surface of the silica samples has been determined by thermogravimetric analysis. Finally an attempt to correlate solid surface characteristics with adsorption isotherms has been developed. 相似文献
4.
5.
针对定径机换辊后定径钢管所出现的质量问题,提出了成品机架的轧辊孔型不分配变形量和适当增大孔型直径的改进措施。 相似文献
6.
采用Tritonx-100为铜、锌、铁、锰的增感剂,对高纯氯化锂中的铜、锌、铁、锰进行了原子吸收光谱分析,结果令人满意。其特征浓度铜为0.018μg.ml-1/1%吸收、锌为0.004μg.ml-1/1%吸收、铁为0.021μg.ml-1/1%吸收,锰为0.011μg.ml-1/1%吸收。 相似文献
7.
8.
9.
TA15合金的热变形行为及加工图 总被引:10,自引:0,他引:10
研究了TA15合金的热模拟压缩实验。结果表明:变形温度的升高和应变速率的减小使峰值应力和稳态应力显著降低,变形温度会影响进入稳态流动所需变形量。以热模拟压缩实验为基础,建立的加工图表明:TA15合金高温变形时存在2个非稳定区域,一个是变形温度1300K以上和应变速率10.0s^-1以上的区域,另一个是变形温度1200K以下和应变速率0.006s^-1~1.995s^-1之间的区域。同时,建立的TA15合金高温变形时的流动应力模型表征了变形温度、应变速率和变形程度对流动应力的影响,模型的计算精度较高。 相似文献