铝合金表面等离子体电解氧化陶瓷涂层在NaCl溶液中的电化学阻抗谱研究

通过调整电解液中硅酸钠的浓度，利用等离子体电解氧化（PEO）技术在铝合金LY12表面制备了各种陶瓷涂层，利用光学显微镜、XRD、电化学阻抗谱（EIS）对涂层的形貌、成分和涂层在NaCl溶液中耐腐蚀性能进行了研究．结果表明：提高电解液中硅酸钠的浓度可以使得涂层的总厚度增加，但过高或过低的浓度都会导致致密层厚度的减薄．当浓度为20g／L时，所制备的涂层的成分以氧化铝为主；当浓度为40g／L时，涂层的成分主要是莫来石和氧化铝；当浓度超过60g／L时，涂层的成分主要为非晶相．EIS的研究表明，涂层耐腐蚀性取决于涂层中的致密层，增加致密层的厚度可以提高PEO涂层的耐腐蚀性，在中性、酸性、碱性腐蚀介质中，PEO涂层都显示出对基体良好的保护作用．

α-异噁唑偶氮基-β-二酮类衍生物及其互变异构体的光谱

研究了5种新型的具有不同结构的aα-异噁唑偶氮基-β-二酮类衍生物的红外光谱和紫外光谱，讨论了它们的酮式-烯醇式以及偶氮式．腙式之间的互变异构化现象。结果表明，所有化合物无论以固体形式或在溶液中均以腙式二酮体和偶氮式烯醇体的混合形式存在。各化合物的紫外吸收谱均呈双峰状，峰值分别处于246～262nm和326～339nm之间，其中，高波长吸收峰的强度明显高于低波长吸收峰强度，说明了各化合物中偶氮式烯醇体形式均多于腙式二酮体形式，其原因是由于各化合物中偶氮式烯醇体的异构体较多，且易以分子内氢键形式形成六元环，

Low-loss planar and stripe waveguides in Nd3+-doped silicate glass produced by oxygen-ion implantation

We report on the fabrication and characterization of low-loss planar and stripe waveguides in a Nd3+-doped glass by 6 MeV oxygen-ion implantation at a dose of 1x10(15) ions/cm(2). The dark mode spectroscopy of the planar waveguide was measured using a prism coupling arrangement. The refractive index profile of the planar waveguide was reconstructed from a code based on the reflectivity calculation method. The results indicate that a refractive index enhanced region as well as an optical barrier have been created after the ion beam processing. The near-field mode profiles of the stripe waveguide were obtained by an end-fire coupling arrangement, by which three quasitransverse electric modes were observed. After annealing, the propagation losses of the planar and stripe waveguides were reduced to be similar to 0.5 and similar to 1.8 dB/cm, respectively. (c) 2007 American Institute of Physics.

激光诱导击穿植物样品等离子体光谱的研究

本文利用Nd:YAG纳秒激光器与配有CCD探测器的四通道光纤光谱仪建立了一套可用于植物样品激光诱导击穿光谱（LIBS）测量的实验装置。基于该实验装置，论文着重开展了激光参数、探测角度、延迟时间等对LIBS 光谱影响以及植物样品LIBS光谱定性、定量分析两方面的实验研究工作。通过实验研究发现：1、在某一激光能量点处，LIBS有最大的相对光谱强度；2、红外（IR）激光击穿阈值要高于紫外（UV）激光，并且IR激光产生的LIBS光谱中连续谱强度也强于UV激光；3、粒子谱线信噪比随时间演化的方式与其产生机制有密切关系；4、光纤与样品表面法线方向夹角越小越容易获得信噪比大的光谱。对所获得的植物样品LIBS光谱分析得到以下结论：1、在230～1080nm范围内，从苹果表皮样品的LIBS中观测到了380余条谱线，鉴别分析出二十多种元素和分子；2、对经过真空冻干处理的三种水果和两种蔬菜样品中的K、Ca、Fe、Na、Mg、Al六种微量元素相对含量分别进行了比较。实验结果表明LIBS技术是分析比较植物样品中微量元素含量的一种有效方法

Preparation of colorless ionic liquids "on water" for spectroscopy

Although colorless ionic liquids (ILs) are most desirable, as synthesized they frequently bear color, despite appearing pure by most analytical techniques. It leads to some uncertainties and limits for the fundamental research and applications of ILs, such as spectroscopy. Using 1-butyl-3-methylimidazolium bromide (BMIMBr), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) and 1-hexyl-3-methylimidazolium bromide (HMIMBr) as models, we demonstrated that following classic preparing method except that the water was added as solvent, colorless ILs could be facilely prepared. Neither critical pre-treatment of starting materials and pre-cautions during the reaction nor time-consuming and costly post-decolor-purification was needed, The effects of "on water" reaction conditions on preparing colorless IL and the reason why using water as solvent could produce colorless ILs were also preliminary investigated.

Electrochemical and bioelectrochemistry properties of room-temperature ionic liquids and carbon composite materials

Room-temperature ionic liquids (RTILs) are liquids at room temperature and represent a new class of nonaqueous but polar solvents with high ionic conductivity. The conductivity property of carbon nanotubes/RTILs and carbon microbeads/RTILs composite materials has been studied using ac impedance technology. Enzyme coated by RTILs-modified gold and glassy carbon electrodes allow efficient electron transfer between the electrode and the protein and also catalyze the reduction Of O-2 and H2O2,