Further examination of the BEBO model with the results of ab initio calculations of a reaction series

The BEBO (bond energy-bond order) model is further examined with results of ab initio calculations on a series of metathetic reactions involving hydrogen transfer. Energies are calculated at the 6–31G^**/PMP2=full/6–31G^** level while the bond-orders are estimated using the 6–31G^** basis set with the geometry optimisation at the single configuration unrestricted Hartree-Fock frame. Our analysis reveals that for all thermoneutral reactions where the making and breaking bonds are collinear in the transition state, the reduced distensions in the transition state structures are same and independent of the bond-order exponent in the BEBO model. For others such displacements increase with the square of the energy changes during reactions. The Bronsted coefficient is examined and is found to be neither strictly parallel to the position of the barrier in the reaction path nor a measure of the ‘transition state’ structure of the system.     

13X分子筛负载Fe催化剂上1,4-二氧六环在空气中完全氧化(英文)

采用浸渍法制备了不同Fe含量的13X分子筛负载的Fe催化剂(Fe/X13),运用N_2吸附-脱附法测得其BET比表面积和BJH孔径分布,采用X射线衍射、扫描电镜、程序升温还原和NH_3程序升温脱附法表征了该催化剂的织构性质.在固定床流动反应器中,以空气为氧化剂、在100-400℃范围内考察了Fe/X13催化剂上1,4-二氧六环的完全氧化反应性能,研究了反应温度、金属担载量和气体空速(GHSV)等条件对催化氧化降解二氧六环反应性能的影响,并在400℃测定了该催化剂反应50h的稳定性,结果表明,6 wt%Fe/13X催化剂表现出最高的催化性能,在400℃,GHSV=24000 h~(-1)的条件下,二氧六环转化率为97%,生成CO和CO_2的选择性达95%,降解产物还包括少量的乙醛、乙二醇-甲酸酯、乙二醇二甲酸、1,4-二氧六环-2醇、1,4-二氧六环-2酮及2-甲氧基1,3二氧戊环.基于这些经色谱-质谱联用仪检测出的产物,提出了可能的1,4-二氧六环降解机理。     

Physicochemical properties and supercapacitor behavior of electrochemically synthesized few layered graphene nanosheets

Journal of Solid State Electrochemistry - The study emphasizes on the scalable production and comparison of few layered graphene nanosheets (FLGNSs). The FLGNSs have been electrochemically...     

A Review on Mechanical Behavior of FRP Composites at Different Loading Speeds

Fiber-reinforced polymer (FRP) composites are increasingly becoming suitable and durable materials in the repair and replacement of traditional metallic materials. The built-in promise of performance assurance and retention of structural integrity in harsh and hostile environments of these materials certainly offers an alternative and attractive avenue for a wider range application to explore its potential to the zenith. The toughest challenge faced by material scientists is to assess and ascertain its behavioral log in a range of loading rates. The heterogeneity and responses of multiple distinct phases to varying loading conditions are most often complex and far away from comprehensive conclusion. Furthermore, composites with common structural polymer matrices quite often absorb moisture during service period. Then, FRPs become a much more complex system to comprehend its sensitivity to experimental variation. The present article emphasizes the need for understanding this perpetual problem of FRPs which might pose a threat to its prospects.     

Chemical Composition and Antioxidant Activity of the Leaf Essential Oil of Cryptocarya amygdalina

Chemistry of Natural Compounds -     

Investigation of energy band gap and its correlation with vacancy defects in Pb1-xNixO nanoparticles synthesized through sol-gel method

Journal of Sol-Gel Science and Technology - Nickel doped lead oxide (Pb1-xNixO) nanoparticles with different concentration (x = 0.00, 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30) of...     

Fashionable Co-operative Sensing of Bivalent Zn2+ and Cd2+ in Attendance of OAc− by Use of Simple Sensor: Exploration of Molecular Logic Gate and Docking Studies

Journal of Fluorescence - The Schiff-base probe H2VL [6,6'-((1E,1'E)-hydrazine-1,2 diylidenebis(methanylylidene))bis(2-methoxyphenol)] is synthesized and structurally characterized by...     

A new,convenient and expeditious synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols in water through a multicomponent reaction

A new, simple and efficient synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols in water by a two-pot four component reaction of ethyl acetoacetate, hydrazine hydrate, aldehyde and ketone in presence K₂CO₃ as the catalyst is described. Use of water as the reaction medium, operational simplicity, mild reaction conditions, application of a cost-effective, nontoxic and easily available catalyst with auto-tandem catalysis, wide substrate scope, easy workup and purification process make the protocol highly attractive.     

Simultaneous quantitation of acetylsalicylic acid and clopidogrel along with their metabolites in human plasma using liquid chromatography tandem mass spectrometry

The interest in therapeutic drug monitoring has increased over the last few years. Inter‐ and intra‐patient variability in pharmacokinetics, plasma concentration related toxicity and success of therapy have stressed the need of frequent therapeutic drug monitoring of the drugs. A sensitive, selective and rapid liquid chromatography coupled with tandem mass spectrometry (LC‐MS/MS) method was developed for the simultaneous quantification of acetylsalicylic acid (aspirin), salicylic acid, clopidogrel and carboxylic acid metabolite of clopidogrel in human plasma. The chromatographic separations were achieved on Waters Symmetry Shield^TM C₁₈ column (150 × 4.6 mm, 5 µm) using 3.5 mm ammonium acetate (pH 3.5)–acetonitrile (10:90, v/v) as mobile phase at a flow rate of 0.75 mL/min. The present method was successfully applied for therapeutic drug monitoring of aspirin and clopidogrel in 67 patients with coronary artery disease. Copyright © 2015 John Wiley & Sons, Ltd.