Bubble wake visualization by using photochromic dye

Wake structure of a single “clean bubble”, rising in rectilinear, zigzagging or spiraling path, is experimentally investigated. A single nitrogen gas bubble was produced in a silicone oil pool and the wake structure development in the rear of the rising bubble was visualized by using photochromic dye. The flexibility of this visualization method enabled us to distinguish wake from drift easily. Both bubble motion and wake structure were recorded by using stereo high-speed video camera simultaneously. We present the first experimental support for the existence of the standing eddy at the rear of the clean bubble, as predicted by a previous numerical study by Ryskin and Leal [1984. Journal of Fluid Mechanics 148, 19-35], Dandy and Leal [1986. Physics of Fluids 29(5), 1360-1366] and Blanco and Magnaudet [1995. Physics of Fluids 7(6), 1265-1274]. We study motion of a pair of vortex filaments, which is called double-threaded type wake, in the case of bubble rising in an axi-asymmetric path. Visualization results of multiple formations of horse-shoe type vortices in one period of zigzag motion of rising bubble with shape oscillations, which has not been observed in previous studies are also presented.     

活性染料的非均相光催化氧化脱色反应研究

使用自制的微球型非均相光催化剂和过氧化氢对两种中温型活性染料活性红MS和活性蓝B进行非均相光催化氧化脱色反应，重点研究了催化剂数量、光辐射强度、染料浓度和pH值对其脱色反应的影响．结果表明，催化剂数量和光辐射强度的增加能够明显提高染料的脱色率和初始反应速率常数，并且在微球型催化剂的存在下，染料的光催化脱色反应可以在碱性条件下进行，而且脱色率仍然超过50％．但是染料浓度的增加会使其脱色率降低．     

酸性蒽醌绿合成新工艺的研究

由1,4,5,8—四羟基蒽醌和对甲苯胺为主要原料,在一个反应器内同时完成了缩合和磺化两步单元反应,合成酸性蒽醌绿染料,并对其反应条件对产物收率的影响进行了研究,确定了最佳合成工艺条件(反应时间16 h、反应温度120℃、原料的配比1:2.2)。     

弱酸性、中性染料对氨纶的染色及其在氨纶上的吸附等温线

通过测试中性染料和不同结构的弱酸性染料在氨纶上的上染率，分析染料结构与上染率的关系，并且研究了1：2金属络合染料在氨纶上的吸附规律，并运用Langmuir和Nernst二元吸附模型对吸附等温线进行了分析。     

多相催化氧化法处理染料废水的研究

以酸性大红为处理对象对多相催化氧化处理工艺的催化剂进行了研制工作．结果表明，过渡金属氧化物中CuO有较高的催化活性，Mn、Ni等金属的氧化物几乎无催化活性；采用沉淀法制备的催化剂的催化活性要比采用浸渍法制备的催化剂高，加入少量的K20有较好的助催化作用，而Ni却有明显的负催化作用．对于COD为632．5mg／L的染料废水，在H2O2投加量为6ml／L时，COD去除率超过70％，色度去除率达99％．     

光催化氧化降解染料中电子转移体的选择

利用两种不同的催化剂，进行了不同光源和不同电子转移体时光催化氧化降解甲基橙和工业染料的实验。用O2作为电子转移体时，催化剂降解效果很低；但以H2O2作为电子转移体时，催化剂在太阳光照射下仅需20min左右就可使甲基橙的降解效果达90％，对浓度为100mg／L的实际工业染料，可达50%-60％的COD去除率和接近完全脱色的效果。通过实验结果得出：电子转移体对电子的有效转移对光催化氧化过程的重要性，并评价出H2O2是比O2更有效的电子转移体。     

多级染料激光放大器中激光增益与放大自发辐射强度的理论研究

利用激光增益和放大自发辐射 (ASE)理论 ,对不同条件下的染料激光放大器的激光增益和ASE强度进行了数值计算。分析了当入射光强远小于和大于有效饱和光强时 ,激光增益和ASE强度与入射光相对强度的关系 ,讨论了在两种条件下ASE系数以及染料池端面反射系数对激光增益和ASE成分的影响。最后利用这些结果 ,对连续激光的多级染料放大系统的优化设计进行了讨论。     

Dye linked conjugated homopolymers: using conjugated polymer electroluminescence to optically pump porphyrin-dye emission

Zinc-porphyrin dye molecules were incorporated into the backbone of a conjugated polymer material by a method, which allowed for the incorporation of only one zinc-porphyrin dye molecule into the backbone of each conjugated polymer molecule. The electronic properties of the homopolymer were established using ultraviolet photoelectron spectroscopy (UPS) for the determination of the electronic energy levels and the injection barrier for holes into the valence band. Pulse radiolysis time resolved microwave conductivity (PR-TRMC) was used to determine the sum of charge carrier mobilities. Electroluminescent devices of the homopolymer itself and of the zinc-porphyrin containing polymer were prepared and the nature of the electroluminescence was characterized. The homopolymer segments were found to optically pump the emission of the zinc-porphyrin dye moities. The homopolymer exhibits blue-green emission and the zinc-porphyrin linked homopolymers emit near-infrared/infrared light. This was demonstrated to be due to electroluminescence pumping of the zinc-porphyrin moieties that were covalently linked to homopolymer material. When only one zinc-porphyrin dye was incorporated into the backbone of each homopolymer molecule complete suppression of homopolymer electroluminescence was observed with exclusive near-infrared emission.     

纳米抗菌锦纶的染色性能

为了探讨纳米材料对锦纶染色性能的影响，在相同条件下，用尼龙费林上染纳米抗菌锦纶和普通锦纶，测试了二者的上染百分率，并对染色前后纳米抗菌锦纶进行扫描电镜分析。结果表明，纳米抗菌锦纶的上染百分率小于普通锦纶，但是二者的显色情况相近；染色后，纳米抗菌锦纶表面的纳米颗粒明显减少，说明染色时有纳米颗粒从锦纶表面脱落。