A comparative study on emergent pollutants photo-assisted degradation using ruthenium modified titanate nanotubes and nanowires as catalysts

Several methods have been used to tailor nanomaterials structure and properties.Sometimes,slight changes in the structure outcomes expressive improvements in the optical and photocatalytic properties of semiconductor nanoparticles.In this context,the influence of the metal doping and the morphology on a catalyst performance was studied in this work.Here,ruthenium doped titanate nanotubes(RuTNT) were synthesised for the first time using an amorphous Ru-containing precursor.Afterwards,the photocatalytic performance of this sample was compared to the one obtained for ruthenium titanate nanowires(RuTNW),recently reported.Two samples,RuTNW and RuTNT,were produced using the same Ru-containing precursor but distinct hydrothermal methodologies.The powders were structural,morphological and optical characterized by X-ray diffraction and fluorescence,transmission electron microscopy,Raman,X-ray photoelectron and photoluminescence spectroscopies.Distinct variations on the structural and optical properties of the RuTNT and RuTNW nanoparticles,due to ruthenium incorporation were observed.Their potential use as photocatalysts was evaluated on the hydroxyl radical photo-assisted production.Both samples were catalytic for this reaction,presenting better performances than the pristine counterparts,being RuTNT the best photocatalyst.Subsequently,the degradation of two emergent pollutants,caffeine and sulfamethazine,was studied.RuTNT demonstrated to be better photocatalyst than RuTNW for caffeine but identical performances were obtained for sulfamethazine.For both catalysts,the degradation mechanism of the pollutants was explored through the identification and quantification of the intermediate compounds produced and several differences were found.This indicates the importance of the structural and morphological aspects of a material on its catalytic performance.     

对美国金矿业基础的评价

<正> 引言1969年,美国对美元作了自动贬值。这一行动导致黄金价格在随后的4年里失去了控制,同时也使美国金矿业得到了复苏。本世纪70年代出现的极度通货膨胀导致了贵金属价格的急剧上涨。因此,人们对金矿的勘探和开采产生了日益增长的兴趣。少数幸存下来的采金者开始焕发了热情,他们都是在金价格长期固定不变而采金成本不断增加的情况下,靠勉强能维持收支平衡的利     

硫矿化在阿斯特拉罕气田硫化氢形成过程中的作用

<正> 阿斯特拉罕凝析气田以硫化氢的浓度高为特征。矿床中H_2S的成因问题,不仅具有理论意义,而且具有实际意义,因为不管是在黑海沿岸的盆地,还是在其它地区,预测高浓度硫化氢聚集的可靠性,在相当大的程度上取决于对H_2S成因的正确认识。关于矿床中硫化氢的成因有两种观点。第     

生态系统和工程

1.引言生态学是研究生物及其生活环境的科学,生物用反馈机理来调整它们的环境。无生命的环境及其中有生命的居住者统称为一个生态系统。一个生态系统小至一滴水,大至整个地球。其范围的限定以进入和排出量可被测知为准,但实际上     

厂内工艺调整减少污泥

本文主要通过简单的工艺调整来减少入海处置污泥的体积,以降低处置费用。采用的技术包括;消化污泥回流、笔析、淘洗——再浓缩,以及高温消化。这里既可使用单项技术,也可多项并用。这类抟术极大部分可通过现有的设备和花费极少的费用付之实施。     

Cultural Relevance for Rural Community Development in China: A Case Study in Bai, Jingpo and Huyaodai Communities of Yunnan Province

A three-year study over the Bai, Jingpo and Huayaodai communities in Yunnan Province reveals that the community development is significantly influenced in various ways by such cultural factors as the concepts of development; concepts and traditions of inter-community relationships, consumption, mar- riage and gender; patterns of decision-making and production, resource and income allocation; as well as the role of information dissemination systems, religion and ritual. Based on the analysis over the interactive relevance between each factor and community development, some strategies and methods for dealing with such a cultural relevance in development projects are recommended.     

陆壳组成与年龄的关系:花岗质岩石中Nd同位素变异所提供的证据

地壳花岗质岩石源区的Nd同位素体系可用来估算与陆壳年龄呈函数关系的陆壳Sm/Nd比值。现已发现,从早太古代到晚元古代,陆壳内花岗岩岩浆源的Sm/Nd比值随年龄的减小而增大,即从球粒陨石值的47%增至64%。这一变化趋势与根据沉积岩的稀土(REE)模式推测的变化趋势相反。观测到的这一变化趋势可能仅适用于地壳的长英质部分,但只要较老地壳比较年轻地壳含有更多的镁铁质(50%对0%),该变化趋势也可应用于整个地壳。因为地球上最古老地壳的某部分可能已被继后的地质过程所破坏,所以该变化趋势可能是地壳组成的保留倾向所致(preservational bias),而不是地壳组成真正随时间发生了变化。同位素数据和地壳年龄的分布表明,整个陆壳的Sm/Nd比值不低于球粒陨石值的60%。地壳的Nd浓度的这个极限值和估算值与质量平衡(要求大陆的Nd含量与约700km深处的地幔中丢失的Nd的量相等)一致。     

一项新的洋底深水钻探计划

<正> 1983年,《格洛玛挑战者》号钻探船回到了美国的加尔维新敦港。16年前,它的首次航行也是从这里开始的。漫长的钻探阶段以96条测线而告终,前后在太平洋、大西洋和印度洋打了600多个深水钻孔。它在大洋钻探中取得的     

气候与健康(二)

大气污染物空气不只是维持生命的氧气和惰性气体氮气的混合物,在其中还掺杂了很多其它气体和固体。在这些掺杂物中,一部分是无害的,但其它的则是有毒的。其中很多组分来自自然界,但人类活动也使这些杂质的含量越来越多。这些污染物的数量随地理条件及气     

乌干达苏库卢碳酸岩杂岩的上覆残积土中的磷酸盐、铌、铁及其它元素资源

<正> 引言 在乌干达东南部,苏库卢碳酸岩杂岩的上覆残积土,构成了一个大型磷酸盐矿床。该矿床已进行过小规模开采,为当地肥料工业提供原料。该矿床也是大量铁、铌矿石的潜在来源。此外,它还含有少量锆和钡。从本世纪40年代到50年代初期,已探明含P_2O_513.1％和含