The use of ATR-IR to identify the components separated by paper chromatography

Summary A modified procedure for the identification of separated components in paper chromatography using attenuated total reflection infrared spectroscopy is described. This combined method, though inferior in sensitivity and resolution to the modern separation systems interfaced with sophisticated analytical instruments, is simple, relatively less expensive and suitable for routine analysis of components like polymer additives.     

Cooperation of reducing species for NO reduction over Ag/Al2O3 under oxidizing conditions

Summary The cooperation effect of reducing species for selective reduction of NO over Ag/Al₂O₃ has been investigated in the presence of excess oxygen. When the combinations of propene or propane and ethanol or methanol were used as reducing agents, NO reduction took place over a wider temperature range, compared with a single hydrocarbon as reducing agent.     

TPSR STUDIES OF THE ACTIVATION OF METHANE ON SUPPORTED PLATINUM CATALYSTS

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New approaches in radical carbonylation chemistry: fluorous applications and designed tandem processes by species-hybridization with anions and transition metal species

New approaches in radical carbonylation chemistry are described. We have successfully integrated tin mediated radical carbonylation chemistry into modern fluorous applications and separation techniques. We revealed that radical carbonylation reactions can be performed using fluorous tin mediators, such as fluorous tin hydride and fluorous allyltin reagents. Fine tuning of the reaction conditions resulted in a good efficiency equivalent to conventional tin mediators. The tedious procedure of removing organotin byproducts can be circumvented through the use of fluorous/organic liquid-liquid extraction or fluorous liquid-solid phase extraction with fluorous reverse phase silica (FRPS). Also described are newly developed tandem carbonylation reactions that are based on species hybridization approaches. Using a radical/anionic hybrid system based on zinc-induced one-electron reduction, we achieved a three-component coupling reaction consisting of 4-alkenyl iodides, carbon monoxide, and electron-deficient alkenes. We observed two types of annulations processes, namely [4 + 1](radical)/[3 + 2](anionic) and [5 + 1](radical)/[3 + 2](anionic), which lead to the production of bicyclo[3.3.0]octanols and bicyclo[3.2.1]octanols, respectively. We found a radical/palladium hybrid system to be useful in the construction of new cyclic systems that incorporate two or three molecules of carbon monoxide.     

Effect of cooperativity on the O-H stretching force constant in associated water species

CNDO/force calculations have been employed to calculate the O-H stretching force constants for various structures of associated water species such as water-dimethylether, water-acetonitrile, water-lithium fluoride, linear and cyclic water polymers. The variation in the O-H stretching force constant in A_m… O-H… D_n species where A_m and D_n represent, respectively,m number of electron-acceptor andn number of electron-donor molecules, is explained on the basis of the cooperativity effect. With increasing electron-acceptor power of A and electron-donor power of D, the hydrogen-bonded O-H stretching force constant is significantly reduced. The results obtained in these studies are in general agreement with experimental observations reported earlier.     

鲨鱼软骨质量的聚类分析法

用电感耦合等离子体原子发射光谱法（ＩＣＰ－ＡＥＳ）测定了１８个鲨鱼软骨真品中１３个元素含量，对测定结果进行分析和变量聚类分析，抽提５个特征指标，并以谱系数聚类建立了鉴别鲨鱼软骨真伪的数学模式，用３个假冒产品和一个鲨鱼软骨胶囊对其进行检验，结果表明，用无机元素所建立的数学模式不仅能鉴别鲨鱼软骨的真伪，还能区分鲨鱼软骨的部分及不同部位的混合物。     

双取代单酰胺与硝酸铀酰萃合物的制备与表征

合成了系列双取代单酰胺萃取剂，利用萃取方法获得了与硝酸铀酰的萃合物。利用元素分析、红外光谱、¹H NMR和¹³C NMR对萃合物进行了表征。结合实验数据初步探讨了萃合物的结构、萃取剂的结构与性能以及萃取体系的三相等问题。     

Photocatalytic and antifouling properties of TiO2-based photocatalytic membranes

Photocatalysis has been extensively studied due to its potential ability to avoid the excessive use of chemical reagents and reduce the energy consumption by employing solar energy. Moreover, to alleviate the reduction in the membrane permeation selectivity, separation efficiency, and membrane service life caused by the emerging micro-pollutants and membrane fouling, membrane technology is often coupled with microbial, electrochemical, and catalytic processes. However, although physical/chemical cleaning and membrane module replacement can overcome the inherent limitations caused by membrane fouling and other membrane separation processes, high operating costs limit their practical applications. In this review, common preparation methods for TiO₂ photocatalytic membranes are described in detail, and the main approaches to enhancing their photocatalytic performance are discussed. More importantly, the mechanism of the TiO₂ photocatalytic membrane antifouling process is elucidated, and some applications of photocatalytic membranes in other areas are described. This review systematically outlines future research directions in the field of photocatalytic membrane modification, including metal and non-metal doping, fabrication of heterojunction structures, control over reaction conditions, increase in hydrophilicity, and increase in membrane porosity.     

Cu-ZSM-5分子筛上[Cu-O-Cu]2+物种的原位红外光谱研究

通过原位监测Ｃｕ－ＺＳＭ－５分子筛的振动动红外光谱随温度及不同处理条件的变化情况,观察到［Ｃｕ－Ｏ－Ｃｕ］＾２＋物种的形成过程,即两个Ｃｕ（ＯＨ）＾＋在脱水过程中经二聚形成［Ｃｕ－Ｏ－Ｃｕ］＾２＋,低交换度样品开始产生［Ｃｕ－Ｏ－Ｃｕ］＾２＋物种所需脱水温度较高,通过观察不同处理条件对［Ｃｕ－Ｏ－Ｃｕ］＾２＋的影响,说明Ｃｕ＾２＋是通过脱出［Ｃｕ－Ｏ－Ｃｕ］＾２＋中的超各氧而被还原为Ｃｕ＾＋,较高     

Real-time onboard wind and windshear determination,part 2: Detection

This paper is concerned with windshear detection in connection with real-time wind identification (Ref. 1). It presents a comparative evaluation of two techniques, one based on the shear/downdraft factor and one based on the wind difference index. The comparison is done with reference to a particular microburst, that which caused the 1985 crash of Flight Delta 191 at Dallas-Fort Worth International Airport.The shear/downdraft factor has the merit of combining the effects of the shear and the downdraft into a single entity. However, its effectiveness is hampered by the fact that, in a real situation, the windshear is accompanied by free-stream turbulence, which tends to blur the resulting signal. In turn, this results in undesirable nuisance warnings if the magnitude of the shear factor due to free-stream turbulence is temporarily larger than that due to true windshear. Therefore, proper filtering is necessary prior to using the shear/downdraft factor in detection and guidance. One effective way for achieving this goal is to average the shear/downdraft factor over a specified time interval . The effect of on the average shear/downdraft factor is studied.