跨国化工企业在我国的投资现状

由于市场、人力资源及成本的优势,跨过公司在我国的投资不断增加,我国已成为全球研发投资项目的最大积聚地。介绍了近几年跨国化工企业在我国投资的项目情况,新一轮的投资主要集中在长江三角洲地区。随着众多跨国公司的签约,催生了南京化学工业园区、上海化学工业区、泉州泉港石化工业区,惠州大亚湾石油化学工业区,同时也将一体化基地的理念带入中国。     

工业有害废物填埋场渗析液处理设计

根据工业有害废物填埋场渗析液中含有多组份重金属以及水量的不连续性和出水回用的特点 ,采用化学处理法与过滤、吸附相结合的方法处理此渗析液 ,使出水达到国标“农业浇灌用水”标准的要求     

考虑地层渗透性各向异性的堤防工程三维防渗结构优化分析

在透水地基上修建长堤防工程,堤基防渗结构的渗控效应直接影响堤防的安全运行。根据岷江干流虎渡溪工程库区长堤防工程地质条件,采用三维渗流分析方法,对堤基高喷防渗墙的布置结构进行优化分析。结果表明：高喷防渗墙可有效降低堤后地下水水位,减小库水向堤后低洼保护区域渗漏,但其渗控效应受防渗结构空间展布长度、深度与渗透性以及地层材料渗透性各向异性的影响。满足低洼保护区域不溢出要求的防渗墙最小展布长度随其布置深度的增大和施工质量的提高而减小,防渗墙渗透系数小于1×10^-5 cm/s并将透水性强的覆盖层截断时,其渗控效应明显,若进一步提升防渗墙质量和布置深度则效果不显著。防渗墙质量的提高对堤防渗控效应的提升受地层材料渗透性各向异性的影响较小,而布置深度增大在渗透性各向异性比较大时对渗控效应与防渗结构优化设计的影响较大。随着地层材料渗透性各向异性比的增大,防渗墙所需最小空间展布长度逐渐增大,由各向同性时的180 m增大到220 m,且当渗透性各向异性比较大时,可能有必要增加防渗墙布置深度。     

基于经验统计的弃渣场失稳致灾距预测模型研究

弃渣场失稳滑坡是一种严重的山地灾害,而对其致灾距离的预测对于灾害的防治具有重要意义。通过收集多组山地灾害数据,并经过处理后提出了滑坡碎屑流致灾距的经验预测模型,并基于此,进一步提出了弃渣场失稳滑坡致灾距的经验预测模型,模型考虑了弃渣体内部因素可能造成的影响,并通过数据拟合对模型的适用性进行了验证。其研究成果具有一定的推广价值。     

Active sites in methanol oxidation on Cu(110) determined by STM and molecular beam measurements

STM has been combined with molecular beam rate measurements to gain an understanding of the oxidative dehydrogenation of methanol to produce formaldehyde, both at the macroscopic and microscopic level. From this a model of the reaction is developed where the methanol initial reacts at very few active oxygen sites located at the short sides of oxygen islands on the Cu(110) surface. Such sites are very much rarer on a surface which is saturated with 0.5 monolayers of oxygen and the reaction rate is initially very low, but shows autocatalytic behaviour, rising in time as vacancies are created in the oxygen layer.     

Possible effects of site isolation in antimony oxide-modified vanadia/titania catalysts for selective oxidation of o-xylene

Titania-supported vanadia catalysts were modified by addition of antimony oxide for application in o-xylene selective oxidation to phthalic anhydride. It was shown that active and selective catalysts can be prepared by ball-milling mixtures of powders of TiO₂, V₂O₅and Sb₂O₃followed by calcination. X-ray photoelectron spectroscopy proves the formation of highly dispersed overlayers of vanadium oxide and antimony oxide, in which V⁵⁺is partially reduced to lower oxidation states and Sb³⁺is partially oxidized to Sb⁵⁺. Antimony oxide segregated into the outermost surface layers. It is therefore inferred that the presence of the antimony oxide modifier spatially separates V–O species and leads to site isolation which may be responsible for the positive effect of the modifier for the catalyst's selectivity.     

金属离子(Na+、K+、Mg2+、Ca2+)与鸟嘌呤活性位点相互作用的理论研究

本文用量子化学从头算方法对金属离子与碱基活性位点的相互作用及其形成配合物的结构和性质进行理论研究.用HF/6-311G*优化鸟嘌呤及其金属离子(Na 、K 、Mg2 、Ca2 )配合物.在HF水平上,运用6-311G*基组计算Ⅰa和Ⅱa族金属离子(Na 、K 、Mg2 、Ca2 )与鸟嘌吟(Guanine)活性位点的相互作用.结果表明:Mg2 、Ca2 离子引起配位体的变形较Na 、K 离子大;Mg2 、Ca2 离子配合物比Na 、K 离子配合物稳定.     

智能站二次设备的运行分析

比较了智能变电站与常规站的管理和结构特点,深入研究了二者的差异以及智能变电站二次设备运行的调试、维护等相关问题,并且提出了几点建议,以期对实际工作起到一定的指导作用。     

The SMSI between supported platinum and CeO2–ZrO2–La2O3 mixed oxides in oxidative atmosphere

CeO₂–ZrO₂–La₂O₃ (CZL) mixed oxides were prepared by citric acid sol–gel method. The as-received gel was calcined at 500, 700, 900 and 1050 °C to obtain the so-called C5, C7, C9 and CK, respectively. The C5, C7 and C9 powders were impregnated with H₂PtCl₆ and then calcined at 500 °C to prepare P5C5, P5C7 and P5C9, respectively. The impregnated CK powders were calcined at 500, 700 and 900 °C to prepare P5CK, P7CK and P9CK, respectively. The XRD and XPS analyses show that the surface distribution of Pt is evidently influenced by the structural and textural properties of the support. The CO adsorption followed by FTIR reveals that the dispersion and the chemisorption sites of Pt are reduced as the calcination temperature of CZL support increases. The chemisorption ability of the CK samples is even completely deactivated. The encapsulation mechanism, which has been applied to explain the so-called strong metal–support interaction (SMSI) after reductive treatment, is introduced here to demonstrate the abnormal observations though the samples were prepared in oxidative atmosphere. The HRTEM results also confirm this explanation. The effects of oxygen vacancies, the chemisorption sites on the Pt surface and Pt/Ce interfacial sites on the three-way catalytic activities are discussed.     

互联网应用发展和用户行为解析

互联网在我国迅猛发展,其应用不断创新发展。本文从搜索引擎、社交网站、电子商务、网络视频、网络游戏、移动互联网6个方面对互联网应用发展现状以及各种用户的行为习惯进行研究．最后分析了各种互联网应用的发展趋势。