Solar photocatalytic degradation of reactive blue 4 using a Fresnel lens

The heterogeneous photocatalytic degradation of reactive blue 4 dye (RB4) solutions under Fenton reagent and TiO(2) assisted by concentrated solar light irradiation using a Fresnel lens has been studied. Multivariate experimental design was applied to study the kinetic process. The efficiency of photocatalytic degradation was determined from the analysis of color and total organic carbon (TOC) removal. Factorial experimental design allowed to determine the influence of four parameters (pH and initial concentrations of TiO(2), Fe(II) and H(2)O(2)) on the value of the decoloration kinetic rate constant. Experimental data were fitted using neural networks (NNs). The mathematical model reproduces experimental data within 86% of confidence and allows the simulation of the process for any value of parameters in the experimental range studied. Also, a measure of the saliency of the input variables was made based upon the connection weights of the neural networks, allowing the analysis of the relative relevance of each variable with respect to the others. Results showed that acidic pHs (pH=3.6) are preferred for the complete dye decoloration. The optimum catalyst concentration is 1.2g TiO(2)/l. The use of a low cost catalyst and its activation using a Fresnel lens to concentrate solar energy significantly accelerates the degradation process when compared with direct solar radiation alone and can offer an economical and practical alternative for the destruction of environmental organic compounds.     

伪装材料表面偏振散射的几何光学解

散射光的偏振特征可以作为遥感信息来识别目标,给伪装技术带来了新的威胁.文中采用偏振相机在光学与红外波段测试了染料型和涂料型伪装材料的偏振散射光谱,研究了不同探测波段下粗糙材料表面的偏振散射机理.研究结果表明:染料型伪装材料的偏振度很小,当光源以不同的入射角照射其表面时,偏振度基本保持不变;涂料型伪装材料的偏振度较大,且随着入射角的增大,其散射光的偏振度也逐渐升高;材料散射光的偏振度与表面粗糙度成反比,染料型伪装材料具有较大的表面粗糙度,在与入射光的作用过程中多次散射占优,因此,其偏振度很小.利用几何光学理论分析了材料表面的偏振散射机理,分析结果与实验结论相吻合.在一定条件下,伪装材料的偏振散射特征与背景不同,偏振信息在伪装目标识别方面具有重要的军事应用价值.     

液晶染料填充一维光子晶体局域模的电场调控及其光激发特性研究

基于液晶的电场调控特性及激光染料作为增益介质的增益模型,通过传输矩阵法理论研究了液晶染料填充一维光子晶体局域模的电场调控及其光激发特性。数值结果表明:随着垂直入射光和电场方向的夹角θ的增大,局域模波长向短波方向移动;当角度θ在(0°,90°)范围内变化时,局域模波长最大调控量达56.7nm;激光染料泵浦后不改变局域模的位置,但局域模的透射率变大了;随着增益系数的增大,局域模透射率先增大后减小,不同局域模对应不同的泵浦阈值,并且随着夹角θ的增大局域模对应的泵浦阈值将减小。     

A short review of activated carbon assisted electrosorption process: An overview, current stage and future prospects

Stepping into the new globalizes and paradigm shifted era, a huge revolution has been undergone by the electrochemical industry. From a humble candidate of the superconductor resources, today electrosorption has demonstrated its wide variety of usefulness, almost in every part of the environmental conservation. With the renaissance of activated carbon (AC), there has been a steadily growing interest in this research field. The paper presents a state of art review of electrosorption technology, its background studies, fundamental chemistry and working principles. Moreover, recent development of the activated carbon assisted electrosorption process, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of electrosorption in the field of adsorption science represents a potentially viable and powerful tool, leading to the superior improvement of pollution control and environmental preservation.     

High efficient aqueous-film rotating disk photocatalytic fuel cell (RDPFC) with triple functions: Cogeneration of hydrogen and electricity with dye degradation

A high efficient aqueous-film rotating disk photocatalytic fuel cell (RDPFC) was proposed for the simultaneous production of hydrogen and electricity concomitantly with the degradation of high concentration dye wastewater. During the experimental period, the accumulation of hydrogen evolution increased linearly, the current intensity remained stable and the chemical oxygen demand decreased gradually in this RDPFC. Under the same condition, the hydrogen generation rate and the electric flow obtained in the RDPFC were 10 times higher than that of the conventional immersion reactor. The whole system operated steadily and exhibited good performance under a long-running process, and the accumulation of hydrogen were 27.9 and 26.2 mL by using 100 mg L⁻¹ rhodamine B and 300 mg L⁻¹ reactive brilliant red X-3B, respectively. The aqueous-film RDPFC represents a promising candidate for the concurrent function of the organic degradation and clean-energy production by utilizing the light energy and wastewater.     

Synthesis,and characterization folate-conjugated photocleavable poly(4-substituted-ε-caprolactone) polymers for drug delivery

Abstract

Photo-cleavable polymers containing 5-hydroxy-2-nitrobenzyl alcohol (ONB) junction point between the target molecule of folic acid (FA) and the hydrophobic poly(4-substituted-?-caprolactone) (PXCL_n) chain were synthesized. FA –terminated ONB-PXCL_n polymers formed micelles with critical micelle concentration (CMC) 1.2 – 64.3?mg L^?1. Fluorescence emission spectroscopy indicated the release of Nile red encapsulated FA-ONB-PXCL_n micelles in response to irradiation. Light-triggered bursts released were observed for drug-loaded FA-ONB-PXCL_n micelles. The nanoparticles exhibited nonsignificant toxicity at concentrations up to 300?µg mL^?1. Flow cytometry revealed that the uptake of folate-targeted doxorubicin (DOX) -encapsulated micelles by HeLa cells was faster than that of free DOX.     

Mass Transport in Shallow Turbulent Wake Flow by Planar Concentration Analysis Technique

A planar concentration analysis (PCA) system is used for observing the transport and mixing of a tracer mass in a shallow turbulent free-surface wake flow of a large cylindrical obstacle. The nonintrusive, fieldwise PCA measuring technique is applied to evaluate depth-averaged mass concentrations by making use of light attenuation due to absorption and scattering processes related to a dissolved tracer mass. The scalar fields are decomposed into a low-frequency quasiperiodic part, the coherent flow, and a randomly fluctuating part. From accompanying near-surface velocity measurements, large-scale coherent structures are identified and related to the coherent mass fields. This allows one to assess the role of the large-scale vortices for advection and diffusion in shallow wake flows. The time–mean wake flow displays a self-similar spanwise distribution both for mass and velocity. The longitudinal development of shallow wakes initially shows the growth of unbounded wakes; in the wake far field an attenuated behavior applies.     

毛/棉交织物直接酸性染料染色研究

本文对直接和酸性染料在毛棉交织两种不同纤维上的染色性能进行了研究,测定了染液pH值、温度、染色时间和中性电解质对不同纤维上染料竭染率和染色速率的影响。初步探讨了不同结构直接染料与羊毛染色性之间的关系。提出毛/棉交织物羊毛留白、纯色染色和交染的适用染料、染色工艺以及防羊毛沾染剂,对生产实践具有指导意义。     

真丝绸接枝染色研究

真丝绸经接枝剂CS接枝改性后,丝纤维上引入一些正电荷基团,增加了阴离子染料的染座,提高染料的上染率。同时真丝绸传统用柴林湖蓝5GM等色泽染色,可用价格较低,且日晒牢度较好的直接翠蓝GL代替。从而达到降低生产成本和提高产品质量之目的。     

染料敏化纳米晶体TiO2太阳电池的研究和进展

染料敏化纳米晶体TiO2太阳电池作为新型太阳电池，已经引起人们的广泛重视。该太阳电池制备方法简单、成本低廉，且能够获得比较理想的光电转换效率。本文详细介绍了染料敏化纳米晶体TiO2太阳电池的研究现状和存在的问题，对该领域的未来发展做出了一些预测。