全文获取类型
收费全文 | 253篇 |
免费 | 84篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 3篇 |
综合类 | 12篇 |
化学工业 | 218篇 |
金属工艺 | 1篇 |
建筑科学 | 7篇 |
矿业工程 | 3篇 |
能源动力 | 10篇 |
轻工业 | 9篇 |
水利工程 | 2篇 |
石油天然气 | 16篇 |
无线电 | 3篇 |
一般工业技术 | 35篇 |
冶金工业 | 2篇 |
原子能技术 | 19篇 |
自动化技术 | 1篇 |
出版年
2023年 | 11篇 |
2022年 | 21篇 |
2021年 | 19篇 |
2020年 | 27篇 |
2019年 | 15篇 |
2018年 | 23篇 |
2017年 | 7篇 |
2016年 | 25篇 |
2015年 | 17篇 |
2014年 | 14篇 |
2013年 | 27篇 |
2012年 | 24篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 12篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1988年 | 2篇 |
1979年 | 1篇 |
1951年 | 3篇 |
排序方式: 共有341条查询结果,搜索用时 15 毫秒
1.
天然气中含汞会对天然气的开发及使用带来危害,实验采用固定床吸附法脱除天然气中的汞。实验以Al2O3和活性炭复合颗粒为载体,通过浸渍法负载S、CuS和CuS x 多组分活性物,制备了天然气脱汞吸附剂,考察了制备工艺条件的影响。采用X射线衍射检测(XRD)与扫描电镜(SEM)对活性物负载情况进行了表征。结果表明,在载体上成功负载了CuS和S,其中CuS质量分数为12.80%,总S质量分数为8.32%。以含汞空气模拟含汞天然气,考察了进气口汞含量、停留时间对脱汞吸附剂脱汞效果的影响。结果表明,脱汞剂处理汞含量为300μg/m3的天然气,停留时间为1s时,出口汞含量为24.99μg/m3,已达到工业天然气要求。当停留时间为2s、进气口汞含量达到600μg/m3时,经脱汞剂脱汞后,出口汞含量为18.92μg/m3,达到小于28μg/m3要求。脱汞吸附剂的汞容量达到6.36%。 相似文献
2.
Phosphine(PH3) is a highly toxic air pollutant,commonly produced in phosphorous chemical industry.But it has received less research attention due to its handling difficultly.CO is the main content of the phosphorous chemical industry tail gas,the concentration of which is always more than 80 vol.%,and it can be the feed gas to produce various valuable products such as formate,oxalate,and methanol and so on.But,PH3 is one of the important barriers,which is harmful to the following chemical process.In order to make use of the tail gas,PH3 should be removed firstly,and CO should be covered in the whole purified procedure at the same time.In this work,the modified activated carbon(MAC) was used as the adsorbent to separate PH3 from the mixture tail gas.Series of MAC adsorbents were prepared for the adsorption of PH3,which loaded Cu-Fe and Ce(La),or separately.The PH3 adsorption capacities,chemical and physical properties of MAC were all investigated.The results showed that over 99% PH3 adsorption efficiency was achieved when used MAC adsorbents.The removal efficiency and PH3 adsorption capacity of the Cu-Fe-Ce/AC(20:1:0.4) were both much higher than those modified activated carbons.The maximum PH3 adsorption capacity was 71 mg of PH3/g of MAC on the Cu-Fe-Ce/AC,which were much higher than literature data using CuO only for adsorbing hydride gases. 相似文献
3.
4.
气态轻烃(C1~C3)如甲烷、乙烯、丙烯分别作为应用最广的清洁燃料和大宗化工产品,在国民经济中占据重要的地位。然而,在其生产过程中广泛存在着分离与提纯能耗较高的问题。金属有机骨架材料(MOFs)作为第三代新型多孔材料,近年来在轻烃分离领域显示出巨大的应用潜力。本文综述了MOFs用于气态轻烃分离的现状和机理,总结了本文作者课题组针对不同轻烃产物的分离要求,对MOFs进行了精确的孔径调控、配体功能化修饰、构筑吸附位点、调变柔性结构“开口压力”等,实现了多种气态轻烃组分的高效分离。最后,针对低碳烃工业分离过程中存在的关键问题,对MOFs材料的吸附分离机理进行了深入分析,以及MOFs工业化应用所面临的结构稳定性与分离工艺匹配等进行了展望。 相似文献
5.
采用硝酸铁与硫脲在溶剂热反应条件下制备FeS2,利用物理浸渍法将FeS2负载至多壁碳纳米管(MWCNTs)上,借助扫描电镜(SEM)、X射线衍射(XRD)、X光电子能谱(XPS)等分析测试手段对制备样品的结构特性进行探究,通过固定床反应器研究模拟烟气氛围下吸附剂对烟气中单质汞的吸附特性。实验考察了不同FeS2负载量、烟气初始汞浓度、床层温度以及O2、NO和SO2对吸附剂脱汞效率的影响。结果表明,制备出的FeS2分散性较好,呈球状晶体,表面均匀覆盖着MWCNTs,成团簇状。当负载量为10%、反应温度为70℃时,FeS2/MWCNTs的吸附效果最好,最高脱除效率能达到100%,60min后脱除效率仍有80.3%。TPD脱附曲线和XPS分析结果进一步表明烟气中的Hg0被氧化成Hg2+以HgS的形式附着在吸附剂表面,证实吸附剂以化学吸附为主。此外,汞脱除效率随初始汞浓度的增加而降低,汞吸附容量却随之增加,60min最高能达到5.1μg/g。酸性气体NO和SO2的存在,占据了吸附剂表面的活性点位,不利于Hg0的吸附,但低浓度NO对吸附剂的整体效果影响不大,抗NO性能较好。 相似文献
6.
The behavior of different acid zeolites in the hydrolysis at room temperature of methyl tert-butyl ether (MTBE) was studied with reference to the possibility of its conversion to more biodegradable products in underground water contaminated by MTBE. The effect of the structure of the zeolite and SiO2/Al2O3 ratio was analyzed. The results indicate that acid H-MFI and H-BEA zeolites are effective in both adsorption and hydrolysis of MTBE and may be applied for both in situ underground water remediation and as protection barrier for wells or leaking tanks. However, other zeolites (mordenite and faujasite) result completely inactive. Furthermore, contrary to what was expected, the increase of the Si/Al ratio promotes the reactivity which is determined by the resistance to diffusion of MTBE in the pores of zeolites and the resistance of back-diffusion of the reaction products. 相似文献
7.
针对热解煤气变压吸附提氢过程,开展了CO2、CO、N2、CH4等主要杂质气体在不同吸附剂上的吸附热力学研究,测量了各种杂质气体在不同温度下的吸附等温线,并通过计算获得了相应的吸附焓。结果发现,温度增加导致CO2、CO、N2、CH4吸附能力减弱,吸附压力的增大导致CO2、CO、N2、CH4吸附量增加。不同吸附剂对CO2吸附能力的顺序:炭分子筛>活性炭>铜吸附剂,不同吸附剂对CO吸附能力的顺序:铜吸附剂>炭分子筛>活性炭,随着吸附压力的增大,N2和CH4吸附焓为定值,不随吸附量变化而变化。 相似文献
8.
9.
C.P. Kaushik Ravinder Tuteja Namrata Kaushik J.K. Sharma 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2009,155(1-2):234-240
The work is carried out to minimize the organic chemical load (unexhausted dye contents) in direct dyes effluent using low cost adsorbents. The studies are made with different direct dyes, i.e. Direct Red 28, Direct Yellow 12, Direct Orange 26 and Direct Blue 1 with various adsorbents. Three different bio/natural materials have been selected as adsorbents. These includes, Sugarcane bagasse pith (SB), Saw dust (SD)—the plant origin products, and Brick powder (BP)—a silica based material obtained from earth's crust on thermal heating. These substances are almost discarded waste products with the possibility of use as adsorbents. Experimental work for the dye removal from the effluent by activated charcoal (AC) has also been carried out and the results are compared with other adsorbents. The amount of unexhausted organic dye present in the effluent is measured as chemical oxygen demand (COD) before and after the treatment. Adsorbent Sugarcane bagasse pith shows good performance as compared to Saw dust and Brick powder. For understanding the behaviour of adsorbents Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) has also been carried out. 相似文献
10.
Pilot studies were undertaken to quantify the total activity of radon that is eluted following no-flow periods from several Ra-226 adsorbents loaded to near exhaustion. The adsorbents studied included two types of barium sulphate impregnated alumina (ABA-8000 and F-1) and Dowex MSC-1 resin treated by either barium hydroxide or barium chloride. In parallel, radium loaded plain activated aluminas and Dowex MSC-1 resin were similarly investigated. The results revealed that radon was quantitatively eluted during the first few bed volumes of column operation after no-flow periods. Although similar radon elution profiles were obtained, the position of the radon peak was found to vary and depended on the adsorbent type. Radon levels up to 24 and 14 kBq dm−3 were measured after a rest period of 72 h from radium exhausted Dowex MSC-1 treated with barium chloride and F-1 impregnated alumina with barium sulphate, respectively. The eluted radon values measured experimentally were compared to those calculated theoretically from accumulated radium quantities for the different media. For plain adsorbents, an agreement better than 10% was obtained. For treated resin-types a consistency within 30% but for impregnated alumina-types high discrepancy between respective values were obtained. 相似文献