全文获取类型
收费全文 | 1095篇 |
免费 | 35篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 21篇 |
综合类 | 1篇 |
化学工业 | 242篇 |
金属工艺 | 32篇 |
机械仪表 | 31篇 |
建筑科学 | 20篇 |
矿业工程 | 5篇 |
能源动力 | 53篇 |
轻工业 | 78篇 |
水利工程 | 8篇 |
石油天然气 | 2篇 |
无线电 | 84篇 |
一般工业技术 | 283篇 |
冶金工业 | 127篇 |
原子能技术 | 5篇 |
自动化技术 | 141篇 |
出版年
2024年 | 4篇 |
2023年 | 12篇 |
2022年 | 28篇 |
2021年 | 48篇 |
2020年 | 48篇 |
2019年 | 43篇 |
2018年 | 45篇 |
2017年 | 43篇 |
2016年 | 28篇 |
2015年 | 31篇 |
2014年 | 42篇 |
2013年 | 77篇 |
2012年 | 36篇 |
2011年 | 53篇 |
2010年 | 53篇 |
2009年 | 54篇 |
2008年 | 41篇 |
2007年 | 32篇 |
2006年 | 22篇 |
2005年 | 23篇 |
2004年 | 12篇 |
2003年 | 18篇 |
2002年 | 22篇 |
2001年 | 14篇 |
2000年 | 12篇 |
1999年 | 11篇 |
1998年 | 37篇 |
1997年 | 23篇 |
1996年 | 17篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 16篇 |
1992年 | 7篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 20篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 15篇 |
1979年 | 9篇 |
1977年 | 3篇 |
1976年 | 11篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1966年 | 2篇 |
排序方式: 共有1133条查询结果,搜索用时 0 毫秒
131.
132.
133.
Wireless Networks - This paper outlines a simple design of a compact wideband microstrip-line fed antenna having two rotated elliptical wide-slots (EWSs). Here, both the elliptical wide-slots are... 相似文献
134.
Synthesis of mesoporous geopolymeric powder from LD slag as superior adsorbent for Zinc (II) removal
Linz-Donawitz(LD) slag Geopolymer(LDSGP), a porous aluminosillicate geopolymeric adsorbent, has been synthesized from steel plant LD slag for efficient removal of Zinc(II) ions from wastewater, thus presenting a solution for converting industrial waste to adsorbent for wastewater treatment. The colloid paste of raw LD slag and the alkaline activator (10?M NaOH?+?sodium silicate (1:1 w/w)) has been cured for 3?days at low temperature to geopolymerize the calcium oxide rich LD slag. The BET surface area of LDSGP adsorbent (30.84?m2/g) has improved considerably compared to raw LDS (4.85?m2/g) and the FESEM and HRTEM images reveal the presence of micropetal and cauliflower like structures at outer surface of the adsorbent particles. The mesoporous nature of LDSGP adsorbent can be understood by analyzing N2 adsorption-desorption and pore size distribution plot. The PXRD pattern of LDSGP adsorbent powder confirms the presence of Ca2SiO4 and Ca3SiO5 in the geopolymeric matrix. Langmuir isotherm model correlates the batch adsorption data of Zn2+ ions onto LDSGP particles at 298?K, 308?K and 318?K. The maximum Zn2+ ions adsorption capacity of LDSGP is 86?mg/g at 318?K. The adsorption kinetic data is correlated with pseudo-second-order model indicating chemisorption of Zn2+ ions onto LD slag geopolymeric powder adsorbent. 相似文献
135.
Potential of migration of active compounds from protein‐based films with essential oils to a food and a food simulant 下载免费PDF全文
Regiane Ribeiro‐Santos Nathália Ramos de Melo Mariana Andrade Ana Sanches‐Silva 《Packaging Technology and Science》2017,30(12):791-798
Migration tests at different temperatures and storage periods were performed to evaluate the release of active compounds from active whey protein films (WPFs) to a food and food simulants. Whey protein film incorporated with different levels of an optimized essential oils (EOs) blend (1%, 2%, 2.7%, and 5%, w/w) were prepared by casting. This blend contained EOs from rosemary and 2 species of cinnamon. Salami was packaged with WPF and stored during 180 days at 5°C. Temperature influenced significantly the migration of compounds (P<.1). It was observed that eucalyptol was the compound that presented the highest potential of migration into 95% ethanol (v/v). After contact of film with salami, it was observed that, in general, more than 50% of active compounds released from WPF to salami. It was observed that higher amounts of active compounds were released to salami than to fatty food simulant. Results suggested that the release of compounds depends on their affinity with the food/food simulant, temperature, their concentration in packaging, and composition of food. Active packaging may ensure the quality of food due the migration of compounds from EO with antimicrobial and antioxidant activity incorporated in the film to the foodstuff. 相似文献
136.
137.
138.
Chakraborty Malay Dey Tina Bera Kamal Kanti Roy Partha Sarathi Ghorai Kalyan Hossain Akbar Bhattacharya Swapan Kumar 《Journal of Materials Science》2022,57(3):2021-2038
Journal of Materials Science - Palladium–bismuth oxoiodide nanocomposites of various molar ratios of Pd and BiOI have been synthesized by the facile solvothermal method following the chemical... 相似文献
139.
Fly ash is milled for 0, 30 and 90?min and used to study the role of particle size on the kinetics of geopolymer formation. The increase in particle fineness is very prominent in the initial milling stage, and then slows down due to agglomeration effect of finer fraction. The fly ash geopolymerization kinetics and its mechanism is determined using heat of reaction data measured by isothermal conduction calorimeter. The improvement in reaction rate with milling is correlated with the median particle size of the fly ash. The apparent activation energy decreases with size reduction because finer fractions are more prone to alkali activation. Although the kinetics changes with particle fineness, but no alternation is detected in the reaction mechanism, governed by nucleation and growth. The apparent activation energy evaluated by rate method is showing three major steps of geopolymerization such as dissolution, gel formation and restructuring. 相似文献
140.
AI & SOCIETY - The advent of the intelligent robot has occupied a significant position in society over the past decades and has given rise to new issues in society. As we know, the primary aim... 相似文献