全文获取类型
收费全文 | 2827篇 |
免费 | 193篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 30篇 |
综合类 | 3篇 |
化学工业 | 673篇 |
金属工艺 | 85篇 |
机械仪表 | 159篇 |
建筑科学 | 100篇 |
矿业工程 | 7篇 |
能源动力 | 106篇 |
轻工业 | 347篇 |
水利工程 | 29篇 |
石油天然气 | 23篇 |
无线电 | 188篇 |
一般工业技术 | 477篇 |
冶金工业 | 159篇 |
原子能技术 | 21篇 |
自动化技术 | 618篇 |
出版年
2024年 | 9篇 |
2023年 | 33篇 |
2022年 | 91篇 |
2021年 | 132篇 |
2020年 | 102篇 |
2019年 | 114篇 |
2018年 | 132篇 |
2017年 | 110篇 |
2016年 | 135篇 |
2015年 | 103篇 |
2014年 | 133篇 |
2013年 | 258篇 |
2012年 | 182篇 |
2011年 | 251篇 |
2010年 | 154篇 |
2009年 | 150篇 |
2008年 | 146篇 |
2007年 | 115篇 |
2006年 | 89篇 |
2005年 | 71篇 |
2004年 | 63篇 |
2003年 | 68篇 |
2002年 | 43篇 |
2001年 | 41篇 |
2000年 | 32篇 |
1999年 | 30篇 |
1998年 | 41篇 |
1997年 | 24篇 |
1996年 | 26篇 |
1995年 | 27篇 |
1994年 | 25篇 |
1993年 | 13篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 12篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1977年 | 2篇 |
1976年 | 9篇 |
1975年 | 5篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1963年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有3025条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Computer‐Interpretable Guidelines (CIGs) are the dominant medium for the delivery of clinical decision support, given the evidence‐based nature of their source material. Therefore, these machine‐readable versions have the ability to improve practitioner performance and conformance to standards, with availability at the point and time of care. The formalisation of Clinical Practice Guideline knowledge in a machine‐readable format is a crucial task to make it suitable for the integration in Clinical Decision Support Systems. However, the current tools for this purpose reveal shortcomings with respect to their ease of use and the support offered during CIG acquisition and editing. In this work, we characterise the current landscape of CIG acquisition tools based on the properties of guideline visualisation, organisation, simplicity, automation, manipulation of knowledge elements, and guideline storage and dissemination. Additionally, we describe the CompGuide Editor, a tool for the acquisition of CIGs in the CompGuide model for Clinical Practice Guidelines that also allows the editing of previously encoded guidelines. The Editor guides the users throughout the process of guideline encoding and does not require proficiency in any programming language. The features of the CIG encoding process are revealed through a comparison with already established tools for CIG acquisition. 相似文献
5.
6.
7.
Gabriel Rodrigues de Almeida Neto Cesar Augusto Gonçalves Beatrice Daniel Rodrigo Leiva Luiz Antonio Pessan 《International Journal of Hydrogen Energy》2021,46(46):23767-23778
This study investigates the preparation of polyetherimide (PEI) – LaNi5 composites films for hydrogen storage. Prior to the polymer addition, LaNi5 was ball-milled at different conditions (250, 350, and 450 RPM) and annealed at 500 °C for 1 h under vacuum. The composites were produced with BM-LaNi5-350 (PEI/LaNi5-350) and annealed BM-LaNi5-350 (PEI/LaNi5-350-TT). Membranes were successfully produced through solvent casting assisted by an ultrasonic bath. The particles dispersion and the film morphology did not change after hydrogenation cycles. In the H2 sorption experiments at 43 °C and 20 bar, the films stored H2 without incubation time; both samples reached a capacity of ~0.6 wt%. The H2 sorption kinetics of PEI/LaNi5-350 was comparable to that of BM-LaNi5-350, whereas PEI/LaNi5-350-TT presented significantly slower kinetics. LaNi5 oxidation was hindered by PEI, showing that it can be explored to improve metal hydrides air resistance. The results demonstrated that PEI films filled with LaNi5 are promising materials for hydrogen storage. 相似文献
8.
Real‐time monitoring by proton relaxometry of radical polymerization reactions of acrylamide in aqueous solution 下载免费PDF全文
Elton Jorge da Rocha Rodrigues Roberto Pinto Cucinelli Neto Pedro José Oliveira Sebastião Maria Inês Bruno Tavares 《Polymer International》2018,67(6):675-683
The potential of time‐domain nuclear magnetic resonance (TD‐NMR) for the real‐time monitoring of solution radical polymerizations is demonstrated. A model system composed of a redox‐pair initiator system, acrylamide as monomer and water as solvent was investigated. A second‐generation continuous wave free precession technique was employed to measure the longitudinal relaxation time constant (T1) of the samples throughout the polymerization reactions. This parameter was shown to be sensitive to the reactant feed free‐radical enhancement of the water molecule relaxation time, making it a good probe to monitor monomer conversion in real time in an automated, non‐destructive fashion. It was found that the T1 value was better than the transverse relaxation time constant (T2) for describing the evolution of the polymerization reactions, due to its greater sensitivity to paramagnetic effects. The TD‐NMR signal variation observed was linked to the formation, propagation and termination steps of the radical polymerization kinetics scheme. These first results may contribute to the application of real‐time monitoring of radical polymerization reactions employing low‐cost and robust TD‐NMR spectrometers. © 2018 Society of Chemical Industry 相似文献
9.
10.
Caio Felippe Curitiba Marcellos Camila M. Senna Figueiredo Frederico W. Tavares Maurício Bezerra de Souza Jr. Paulo Laranjeira da Cunha Lage João Francisco Cajaiba da Silva Argimiro R. Secchi Amaro G. Barreto Jr. 《加拿大化工杂志》2020,98(11):2435-2450
An experimental methodology for inferring brine dissolution rate in monoethylene glycol (MEG) solutions at different temperatures using a webcam combined with a mathematical model is presented. The measurement system is designed to track the RGB (red, green, and blue) colour variations during the dissolution process. A dynamic model augmented with the population balance equation is applied to describe the dissolution process. Moreover, the dissolution rate is consistently related to the temperature and MEG concentration through the driving force based on the Gibbs energy and chemical affinity. The applied low-cost measurement apparatus proved to be a useful resource for tracking the dissolution dynamics in a wide range of undersaturation. 相似文献