氮气电化学合成氨催化剂研究进展

氮气是储量丰富且廉价易得的氮源,但无法被人类或动植物直接吸收利用,只有通过化学或生物方法将空气中游离的氮气转化为含氮化合物才能被人类应用于食品或其他工业生产中,因此氮气的固定及转化已经逐渐成为新的研究热点。而氨是一种非常重要的无机化工产品,其在农业、医药、储能等行业中有着重要的作用,且需求量随着社会日益发展和人口的不断增加而不断增加。首先简单介绍了现有的氮气固定合成氨方法及其作用机理,随后重点综述了氮气电化学合成氨催化剂的研究现状,最后对氮气电化学合成氨催化剂的未来发展趋势进行了展望。     

徐工XM200KⅡ铣刨机助力京沈高速养护

<正>近日,在京沈高速沈阳段养护施工过程中,徐工XM200KⅡ铣刨机凭借出色的设备性能和铣刨效果成为该工程"攻城拔寨"的急先锋,给施工方留下了深刻的印象。项目概况京沈高速不仅是连接北京和沈阳的高速公路,而且也是东北地区通往首都北京的重要通道。京沈高速始于北京市东四环路,终至沈阳市过境绕城高速公路,于1999年9月通车,全长658.7 km,双向6车     

知行合一(上)——设计素描 苏州大学建筑学院基础教学平台造型基础课程探索与实践

对设计专业的造型基础训练,我们希望素描不仅是对"形"的捕捉和"体"的塑造,更重要的是对物体及空间维度的训练,对图形推演拓展的过程,使形与形、形与体能够形成逻辑性的关系,记录路径及能使形而下的表象对应形而上抽象的文字,使其互为对应和表达,所以将素描前置了"设计"二字。     

济南中铁城项目地源热泵设计方案分析

济南中铁城项目采用地源热泵系统作为辐射供冷供热+置换新风系统的冷热源,可以在全年需要时随时制冷或者制热。从设计角度深入分析了地源热泵系统在这种特殊空调系统中方案的比选。     

虹口区建成上海市首家养老院食品药品科普站

<正>6月25日,虹口区食药安办、虹口区市场监督管理局举行2019年食品安全宣传周主题日活动暨兰公馆养老院食品安全科普站启动仪式。虹口区市场监督管理局陈玮副局长、虹口区民政局周淳副局长、曲阳街道沈敏副主任和兰公馆创始人张莉颖共同为上海市食品药品科普站揭牌。这是上海首家建在养老院里的食品药品科普站,以"科普站+快检站"的双站模式将食药科普服务送到老年朋友身边,为老年朋友"量身定做"咨询、快检、科普宣传等服务。快检站可以现场检测蔬菜的农药残留、猪肉里的瘦肉精等,一方面培训养老院工作人员,让他们掌握简易的快检项目,对食堂食材等开展快检自查,不出养老院就能搞清     

模糊综合评价法在医生评价系统中的应用

本文以Java和模糊数学为基础并使用后台框架设计了医生综合评价系统。系统以easyUI为前端框架,后台在业务处理上使用spring、SpringMVC等框架,在数据处理上融合了模糊综合评价算法。整个系统逻辑严谨,结构稳定,数据处理科学,评价结果准确。     

Amination of biochar surface from watermelon peel for toxic chromium removal enhancement

Watermelon peel residues were used to produce a new biochar by dehydration method. The new biochar has undergone two methods of chemical modification and the effect of this chemical modification on its ability to adsorb Cr(VI) ions from aqueous solution has been investigated. Three biochars, Melon-B, Melon-BO-NH_2 and Melon-BO-TETA, were made from watermelon peel via dehydration with 50% sulfuric acid to give Melon-B followed by oxidation with ozone and amination using ammonium hydroxide to give Melon-BO-NH_2 or Triethylenetetramine(TETA) to give Melon-BO-TETA. The prepared biochars were characterized by BET, BJH,SEM, FT-IR, TGA, DSC and EDAX analyses. The highest removal percentage of Cr(VI) ions was 69% for Melon-B,98% for Melon-BO-NH_2 and 99% for Melon-BO-TETA biochars of 100 mg·L~(-1) Cr(VI) ions initial concentration and 1.0 g·L~(-1) adsorbents dose. The unmodified biochar(Melon-B) and modified biochars(Melon-BO-NH_2 and Melon-BO-TETA) had maximum adsorption capacities(Qm) of 72.46, 123.46, and 333.33 mg·g~(-1), respectively.The amination of biochar reduced the pore size of modified biochar, whereas the surface area was enhanced.The obtained data of isotherm models were tested using different error function equations. The Freundlich,Tempkin and Langmuir isotherm models were best fitted to the experimental data of Melon-B, Melon-BO-NH_2 and Melon-BO-TETA, respectively. The adsorption rate was primarily controlled by pseudo-second–order rate model. Conclusively, the functional groups interactions are important for adsorption mechanisms and expected to control the adsorption process. The adsorption for the Melon-B, Melon-BO-NH_2 and Melon-BO-TETA could be explained for acid–base interaction and hydrogen bonding interaction.