Bi@Bi4Ti3O12/TiO2 films on glass with photocatalytic and self-cleaning performance

A stable and translucent Bi@Bi₄Ti₃O₁₂/TiO₂ film was fabricated on conventional glass substrates for the first time. The film exhibited a good photocatalytic performance and efficient self-cleaning capability against organic dyes under full spectral irradiation and visible light irradiation. Bi₄Ti₃O₁₂/TiO₂ film was first prepared on a glass substrate with colloidal silica as a high temperature binder, followed by implantation of nanoscale Bi in it by an in-situ partially reduction of Bi₄Ti₃O₁₂ to generate Bi@Bi₄Ti₃O₁₂/TiO₂ films. The improved photocatalytic ability is probably attributed to the surface plasmon resonance of Bi atom as well as the enhanced electron transfer efficiency and synergistic effect of Bi₄Ti₃O₁₂ and TiO₂. According to trapping experiments, hydroxyl radicals (OH) were active species in the photocatalytic degradation of dyes under full spectral light irradiation and possible photocatalytic mechanism was proposed. The film prepared in this work may well have potential practical applications in many aspects, such as cleansing treatments for high building external decorative panels and also systematic characterization of the film suggests that the in-situ reduction is an effective and simple way to produce nanoscale Bi@Bi₄Ti₃O₁₂.     

甲醇氧化生产甲醛装置的工艺查定及分析(Ⅱ)

采用简捷法对两个吸收塔分别进行了计算 ,求出了理论级数、液气比、吸收率及尾气与吸收液的量和组成     

Investigation on infrared laser desorption of solid matrix using scanning electron microscope and fast photography

Infrared light from a pulsed optical parametric oscillator laser system was used to irradiate succinic acid (SA), a usual solid matrix used in matrix‐assisted laser desorption ionization, under vacuum. Ablated SA particles were trapped using a silica plate mounted 3.0 mm above and parallel to the sample surface. The morphology and particle size of ablated particles at different laser fluences were investigated using a scanning electron microscope (SEM). The dynamics of plume propagation for SA desorption process was studied with fast photography at atmospheric pressure. Plume expanding at 1.12 J/cm² laser fluence was recorded using a high‐speed CMOS camera and corresponding propagation distance was measured. The solid matrix desorption was driven by phase explosion according to plume model fitting, which was consistent with the results of SEM. Microsc. Res. Tech. 76:744–750, 2013. © 2013 Wiley Periodicals, Inc.     

改进LMD及高阶模糊度函数的管道泄漏定位

针对天然气管道泄漏定位的问题,提出一种基于改进局域均值分解(LMD)及高阶模糊度函数的时延估计方法。该方法首先采用改进的LMD对声发射信号进行分解,获得多个PF分量,进而提出根据K-L散度的PF分量自动选择算法,获取含有主要泄漏信息的PF分量,在此基础上,研究了基于高阶模糊度函数计算声发射信号的时频参数,并通过时频分析获取特征频率的到达时间差,最后结合泄漏产生的广义声发射信号的传播速度完成对天然气管道泄漏的定位。实验结果表明,提出的方法能够进行定位且精度较直接相关法明显提高。     

面向触觉力反馈的可穿戴柔性执行器研究现状

随着最新一代电子产业在可穿戴性、轻便性、舒适性等方面的需求,近年来基于柔性电子材料的执行器设计制造技术已成为商业消费电子和科研领域关注的热点。柔性执行器由柔性材料加工制作,与刚性执行器相比具有更优的轻薄性、柔韧性和适形性,在可穿戴设备的触觉力反馈中可对皮肤产生多种深浅、节拍和加速度可控的多点作用力,协同产生捏、按、拉等触觉行为,并且整体装置轻巧便捷。分类综述针对触觉力反馈的柔性执行器技术,从主体材料和驱动原理两方面对柔性执行器的工作机制和优缺点进行总结,分析了柔性执行器在虚拟现实、教育培训、医疗辅助等领域的应用情况和潜在价值。对用于实现触觉力反馈的柔性执行器的问题和研究难点进行了总结,并得出设计出安全、舒适、美观、安静等性能优良的柔性执行器是促进未来人机交互的研究突破点。     

岩体质量的现场估计

本文介绍了一种在现场用振动衰减系数来估计岩体质量的新方法。从三个混凝土坝址岩体的实测数据表明,此法具有操作简便,快速,观测范围较大的特点。     

Synthesis and characterization of new fluorinated aromatic polyesters containing trifluoromethylphenoxy pendant groups

A series of novel fluorinated aromatic polyesters containing trifluoromethylphenoxy pendant groups was synthesized by interfacial polycondensation of 2‐(4‐trifluoromethylphenoxy)terephthalyl chloride with various bisphenols in dichloromethane. The polyesters obtained in good yields had weight‐average molecular weights of 70,600–29,800 g/mol, polydispersities of 1.81–2.08, and were all amorphous. All polyesters were easily soluble in organic solvents such as N,N‐dimethylformamide, tetrahydrofuran, o‐chlorophenol, pyridine, and dichloromethane. These fluorinated polyesters showed glass transition temperature of 133–210°C, and good thermal stability with almost no weight loss up to 378°C, the 10% weight loss temperature of 472–523°C as well as char yield of 32–63% at 600°C in nitrogen. These polyester films cast from chloroform solutions exhibited tensile strengths ranging from 102 to 126 MPa, elongation at break from 6.3% to 11.7%, and tensile moduli from 2.1 to 3.3 GPa. The resulting polyester films also displayed low dielectric constants between 2.18 and 2.49 (1 MHz), high transparency with an ultraviolet‐visible absorption cut‐off wavelengths in the 332–355 nm range, and excellent electric strengths (50.4–65.6 kV/mm) and volume resistivity (2.51–6.03 × 10¹⁶ Ω cm). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

甲醇氧化生产甲醛装置的工艺查定及分析(Ⅰ)

对湖北省宜化股份有限公司 3 .5万t·a-1甲醛生产装置进行了物料查定 ,以工厂生产参数和分析结果为依据 ,计算了反应原料的氧醇比、水醇比、配料浓度 ,校核了反应器的选择性、转化率、收率 ,列出了物料衡算表     

Promoted hydrogen release from 3LiBH4/MnF2 composite by doping LiNH2: Elimination of diborane release and reduction of decomposition temperature

The evolution of diborane accompanying H₂ release during the decomposition of transition metal borohydrides reduces the purity of evolved hydrogen and results in capacity loss during cycling. To solve the problem, a small amount of LiNH₂ is doped into a 3LiBH₄/MnF₂ composite and the decomposition properties are investigated. The results show that after doping LiNH₂, the formation of diborane during decomposition is effectively suppressed meanwhile the decomposition temperature is significantly reduced. Around 5 wt.% pure hydrogen can be released at 95–140 °C from 5 wt.% LiNH₂-doped 3LiBH₄/MnF₂ composite. These improvements in the decomposition performance are mainly attributed to the prevention of the formation of B–H–B bonds for B₂H₆ and the destabilization of B–H bonds in borohydrides by the interaction of BH₄⁻ and NH₂⁻.