Photocatalytic degradation of Acid Red 4 using a titanium dioxide membrane supported on a porous ceramic tube

A photocatalytic membrane supported on a porous ceramic tube was described, in which permeation of solutes through the membrane and tube and photocatalytic reaction occur simultaneously. In this photocatalytic membrane reactor, TiO(2) catalyst was coated on the surface of a porous ceramic tube and all experiments were conducted in one pass dead-end system. The objectives of this study are to demonstrate the predominance of dead-end operation and to determine the reaction kinetics model of the photocatalytic reaction. Acid Red 4 (AR 4) dye was used as a model pollutant. A detailed study of physical parameters including flow configurations (dead-end and cross-flow), flow rate, initial dye concentration, light intensity and catalyst loading has been performed to obtain the reaction kinetics. The simultaneous effect of light intensity and catalyst loading was also determined experimentally. Experiments were also conducted to compare the photocatalytic degradation of AR 4 in the dead-end and cross-flow system. The major findings of this study are: (1) the decomposition ratios for dead-end system were three and five times higher than cross-flow system at flow rates of 6.67x10(-8) and 4.00x10(-7)m(3)/s, respectively. (2) The decomposition ratio increased with increasing catalyst loading and light intensity, but remained constant at higher catalyst loading. (3) The decomposition ratio was found to be decreased with increasing flow rate.     

Optimal design base shear forces for reinforced concrete buildings considering seismic reliability and life-cycle costs

The objective of this study is to propose a novel estimation procedure for optimal design base shear forces for reinforced concrete (RC) buildings while considering the seismic reliability and life-cycle costs (LCCs) incurred by life-cycle earthquake events. By simulating life-cycle earthquake events within a specified period and using nonlinear dynamic analysis, including earthquake occurrences and their peak ground accelerations (PGAs), this study also derives the damage states of an RC building considering the effect of the cumulative damage. Additionally, besides life-cycle earthquake events, a simplified model is developed to modify the structural properties of a structure without seismic repair after earthquakes. Given the uncertainty of the occurrence time and PGAs of earthquake events, the seismic reliability, and expected current values of LCCs are calculated using Monte Carlo simulation. Although the case study addresses only an RC building with five stories in Taipei, optimal design base shear forces for low-rise RC buildings calculated via the same procedure can be derived and utilized when making decisions on the seismic level of a building based on safety and economic considerations. Therefore, the proposed method can help both owners and investors to identify LCCs of RC buildings due to seismic structural damage within a specified service life.     

输电线路覆冰研究综述

输电线路覆冰是一种严重的自然灾害,可引发输电线路过荷载、导线舞动、绝缘子串闪络等事故,严重危害电力系统的安全运行。总结和分析了国内外输电线路典型覆冰事故、覆冰的种类与性质、影响覆冰的因素、绝缘子冰闪特性的研究以及输电线路覆冰机理的研究。分析结果表明:绝缘子覆冰闪络问题日渐突出;影响绝缘子覆冰的因素很多,其中电场对绝缘子覆冰的影响不容忽视。     

Design and Optimization of Gradient Interface of Ba0.4In0.4Co4Sb12/Bi2Te2.7Se0.3 Thermoelectric Materials

A series of Ba_0.4In_0.4Co₄Sb₁₂/Bi₂Te_2.7Se_0.3 (FS/BT) thermoelectric (TE) materials were fabricated by a two-step spark plasma sintering method. The samples contained various numbers of gradient layers between FS and BT as follows: one gradient layer (1GL) with FS/BT volume ratio of 5:5, three GLs with ratios of 3:7, 5:5, and 7:3 (denoted as 3GLs-I with 3:7?C5:5?C7:3), 3GLs-II with 7:3?C5:5?C3:7, 5GLs-I with 3:7?C4:6?C5:5?C6:4?C7:3, and 5GLs-II with 2:8?C3:7?C5:5?C7:3?C8:2. The interfacial structure and mechanical properties of the FS/BT TE materials were investigated in this work. In FS/BT TE materials with no GLs, a large number of macroscopic cracks occurred on the FS bulk material side. It was discovered that designing and optimizing GLs between the FS and BT bulk materials could effectively relax the thermal stress induced by the large difference in coefficient of thermal expansion, eliminating the macroscopic cracks and resulting in a remarkable enhancement of the interfacial mechanical properties of the FS/BT TE materials. The flexural strength of the FS/BT TE material with 1GL reached 9.67?MPa, increased by 85% compared with that of the FS/BT TE material with no GLs. The present work indicates that increasing the BT content in the GL near to the FS bulk material side is an effective method to completely eliminate macroscopic cracking. The optimized gradient interface of the FS/BT TE material was 3GLs-II with FS/BT volume ratios of 3:7?C5:5?C7:3. The highest flexural strength reached 12.76?MPa, representing a 144% increase.     

表面增强拉曼光谱快速检测香蕉中的苯醚甲环唑和毒死蜱残留

目的 基于双重基底的表面增强拉曼光谱对香蕉中苯醚甲环唑与毒死蜱进行定性和定量检测。方法 采用银溶胶作为柔性衬底, 增强芯片作为固体基底, 实现双信号放大策略。选用香蕉这种常见的热带水果作为基质, 向香蕉基质中加入不同浓度苯醚甲环唑和毒死蜱标准溶液, 利用QuEChERS法对香蕉中农药残留进行提取, 通过表面增强拉曼光谱技术对两种农药进行定量分析。结果 在0.1~5.0 μg/mL范围内, 苯醚甲环唑和毒死蜱的特征峰强度和浓度之间均满足线性关系, 相关系数分别为0.9794、0.9773,方法检出限分别为0.16mg/kg、0.032mg/kg。结论 本研究建立了一种基于双重基底的表面增强拉曼光谱技术,为香蕉中苯醚甲环唑和毒死蜱农药残留快速检测提供了依据, 也为热带水果中农药残留的快速检测提供了方法支持。     

钢筋混凝土箱梁变厚悬臂板的有限元计算与分析

本文通过通用有限元软件ANSYS计算,指出变厚悬臂板不宜再采用规范公式,推荐设计采用基于壳单元模型的有限元方法进行计算与分析。     

基于骨架树描述符匹配的物体相似性度量方法

提出了通过匹配骨架树来度量物体相似度的新方法.该方法用一种新的物体特征-树描述符来表示一个骨架树,用搜索树描述符中最长公共子串的方法获得最大同构子树;用新的模型度量骨架枝的形状相似性,并把形状特征和拓扑特征的有机的结合起来.最后,对骨架有环和骨架上有噪声的情况进行了讨论.实验结果表明,本方法计算的相似度具有物体的旋转、大小、平移不变性,算法时间复杂度为o（n^3）,n为物体骨架枝数,对多种物体取得了令人满意的结果.     

中原油田矿场试验中三元共聚物胶状体驱油溶液粘度损失问题

中原油田将新研制的耐温 (90℃ )、耐矿化度 (1.6× 10 5mg/L)的丙烯酰胺三元共聚物中试胶状体产品用于小规模矿场驱油试验 ,发现现场配制的溶液粘度较中试初期产品溶液粘度室内测定值下降 6 9%。探讨了引起粘度损失的原因 ,结果如下。①产品质量低且不稳定 :现场试验期间所用产品的溶液粘度比中试初期产品下降 2 9% ,同一批次产品溶液粘度相差 44 % ,不同批次产品溶液粘度相差 5 9%。②造粒机结构不合理 ,运行参数欠当 ,造成溶液粘度损失最大达 2 2 .8%。③螺杆泵输送中粘度损失仅 1.7%。④注聚泵剪切造成粘度损失 4% (规定要求 <5 % )。大庆油田早期 (1972 ) ,胜利油田近期 (1998～ 2 0 0 1)曾在现场驱油试验中使用胶状体HPAM ,效果均欠佳。在聚合物驱油中应使用质量合格并稳定的聚合物和合格的配液设备     

Transparent Raman-enhancing substrates for microbiological monitoring and in situ pollutant detection

Opaque Raman-enhancing substrates made of Ag nanoparticles on incompletely oxidized aluminum templates have been rendered transparent by an ion-drift process to complete the oxidation. The result shows that the transparent substrates exhibit high/uniform surface-enhanced Raman scattering (SERS) capability and good optical transmissivity, allowing for concurrent SERS characterization and high contrast transmission-mode optical imaging of S. aureus bacteria. We also demonstrate that the transparent substrates can used in conjunction with optical fibers as SERS sensors for in situ detection of malachite green down to 10(-9) M.     

Dynamic Resource Allocation for Scalable H.264/AVC Video Transmission over MIMO Wireless Systems

In this study, a channel selection algorithm is proposed to enhance the transmission rate for scalable video coding (SVC) source transmission over multi-input multi-output (MIMO) wireless systems. The proposed algorithm allows each layer of SVC video to choose its appropriate channel in wireless MIMO systems based on channel state information for transmission rate enhancement. Here, this difficult problem is converted into mathematical optimization problem to improve the performance of SVC video transmission. Experimental results show that the transmission rate of the proposed method outperforms the existing scheme.