Scanning microelectrochemical characterization of the anti-corrosion performance of inhibitor films formed by 2-mercaptobenzimidazole on copper

The aim of this work is to explore the applicability of the scanning electrochemical microscope (SECM) to characterize the inhibiting effect of 2-mercaptobenzimidazole against the corrosion of copper. SECM was operated in the feedback mode by using ferrocene-methanol as redox mediator, and the sample was left unbiased at all times. The kinetic changes in the corrosion processes were monitored over time from the Z-approach curves. Furthermore, inhibitor-modified copper samples presenting various surface finishes were imaged by SECM and the scanning vibrating electrode technique (SVET), allowing changes both in the surface activity of metal-inhibitor films and in the extent of corrosion attack to be spatially resolved. Differences in the local electrochemical activity between inhibitor-free and inhibitor-covered areas of the sample were successfully monitored.     

Homogeneous catalyzed reaction of carbon disulfide and o-phenylene diamine by tetrabutylammonium hydroxide in the presence of potassium hydroxide

The catalyzed reaction of o-phenylene diamine and carbon disulfide to synthesize 2-mercaptobenzimidazole (MBI) by tetrabutylammonium hydroxide (QOH; Q: (C₄H₉)₄N) was carried out in a homogeneous solution. A mixture of organic solvent (aprotic or protic) and water of an appropriate volume ratio acts as the homogeneous organic solution. The reaction is greatly enhanced either by tetrabutylammonium hydroxide or by tetrabutylammonium bromide in the presence of potassium hydroxide. Effects of the reaction conditions including the concentration of QOH, concentration of KOH, amount of CS₂, organic solvents, volume ratio of organic solvent to water, and temperature on the conversion of o-phenylene diamine are investigated in detail. An explanation is provided for the peculiar phenomena in studying the effects of the concentration of KOH on the conversion of o-phenylene diamine.     

Kinetic study of S-alkylation of 2-mercaptobenzimidazole by allyl bromide in the presence of potassium hydroxide

The S-alkylation (substitution on sulfur atom) of 2-mercaptobenzimidazole (MBI or ArSH) by allyl bromide (RBr) was successfully carried out in an aqueous solution of KOH/organic solvent two-phase medium. The reaction, which may take place either in the organic phase or on the interface, is greatly enhanced in the presence of KOH without the aid of quaternary salts as the catalyst to promote the reaction. No product was obtained from N-alkylation (substitution on nitrogen atom) during or after the reaction period by using a limited amount of allyl bromide (RBr) relative to that of MBI. Based on the experimental evidence, the kinetic behaviors and the characteristics of the reaction are sufficiently described by the pseudo-first-order rate law. The effects of the reaction conditions, including the agitation speed, the amount of KOH, volume of water, volume of dichloromethane, amount of allyl bromide, amount of 2-mercaptobenzimidazole, organic solvents and temperature on the conversion of allyl bromide and the apparent rate constants (k_app) were investigated in detail. Peculiar result is obtained in studying the effect of the volume of water on the conversion (or the reaction rate) in this work. Rational explanations are provided for the observed phenomena from experimental results.     

Pipeline politics—A study of India′s proposed cross border gas projects

India′s energy situation is characterized by increasing energy demand, high fossil fuel dependency, large import shares, and significant portion of population deprived of modern energy services. At this juncture, natural gas, being the cleanest fossil fuel with high efficiency and cost effectiveness, is expected to play an important role. India, with only 0.6% of proven world reserves, is not endowed with adequate natural gas domestically. Nevertheless, there are gas reserves in neighbouring regions which gives rise to the prospects of three cross border gas pipeline projects, namely, Iran–Pakistan–India, Turkmenistan–Afghanistan–Pakistan–India, and Myanmar–Bangladesh–India. This study is a political analysis of these pipeline projects. First, it provides justification on use of natural gas and promotion of cross border energy trade. Then it examines these three pipeline projects and analyses the security concerns, role of different actors, their positions, shifting goals, and strategies. The study develops scenarios on the basis of changing circumstances and discusses some of the pertinent issues like technology options for underground/underwater pipelines and role of private players. It also explores impact of India′s broader foreign relations and role of SAARC on the future of pipelines and proposes energy induced mutually assured protection (MAP) as a concept for regional security.     

智能LED信息显示屏控制系统设计与应用

针对传统点阵显示屏显示内容难以脱机更新、读写数据缓冲和扫描速度不匹配容易造成闪屏的问题,介绍了一种以ATMEGA32为核心的可旋转式智能LED信息显示屏控制系统的设计方案。硬件上利用MBI5026提升显示驱动能力,并利用ADXL202实现重力识别和显示信息自动转向的旋转功能。软件上利用编程实现汉字拼音输入功能,实时更新显示信息,还构建了行列扫描优化模型,根据模型最优解合理设置行列扫描数目和次数,可在现有硬件资源的基础上将扫描速度提升至最优状态。实践证明,系统具有显示亮度智能调节、外围电路简单和易安装升级等优点,有很好的工程实用价值。     

Clinical relationship of meibometry with ocular symptoms and tear film stability

Purpose

To evaluate the relationship between meibometry with both ocular symptoms and tear film stability by: (1) to find out whether meibometry is able to differentiate between dry eye symptomatic and asymptomatic subjects classified by standardized dry eye questionnaires (OSDI and McMonnies), and (2) to assess the clinical relationship between meibometry with both tear break-up time (BUT) and maximum blink interval (MBI).

LED显示屏驱动芯片的应用

介绍了LED显示屏驱动芯片种类及关键参数,并对比了一些LED屏驱动IC的应用方案,总结出各种方案的优缺点,最后对芯片的应用提出了一些建议.     

Effects of Different Spatial Resolution of Remote SensingImages on Estimation Accuracy of Urban Building Height

In this study,the remote sensing images of WorldView-2,GF-2,and GF-1,which cover Xiamen Software Park,were selected for study.A building and shadow extraction process suitable for different images was constructed,which applied object\|oriented approach and morphology ideas combined with spectral,shadow and shape constraints.Subsequently,the building heights of three different spatial resolutions of 0.5 m,1 m and 2 m were estimated by using the shadow length estimation method.Finally,the influence of image spatial resolution on building extraction accuracy and building height estimation accuracy was evaluated quantitatively.The main conclusions are as follows：(1) The improved building and shadow extraction process achieves higher extraction accuracy,but accuracy decreases slightly with the decrease of spatial resolution of images;(2) With the decrease of spatial resolution,the accuracy of building height estimation decreases gradually,but it does not show linear relationship.At the resolution increases from 1m to 0.5 m,the accuracy of building height estimation increases faster than the resolution increases from 2 m to 1 m;(3) GF-1 is more suitable for height estimation of high\|rise buildings and GF-2 is suitable for middle and high rise buildings,while WorldView\|2 has higher estimation accuracy for building height in different height ranges.