用射频磁控溅射法在二氧化硅衬底上制备磁光Ce∶YIG薄膜

使用射频磁控溅射法在非晶态的二氧化硅衬底上制备Ce1YIG磁光薄膜。生成的Ce1YIG薄膜为非晶态形式 ,经过后续的热处理过程 ,转变为晶化薄膜 ,在用波长为 6 30nm的激光测量时 ,薄膜的饱和法拉弟旋转系数θF 为 80 0°/mm。晶化薄膜具有很强的平行于膜面的磁化强度 ,用VSM测得晶化薄膜的居里温度为 2 2 0℃。实验结果表明 :所制备的薄膜适宜于制备波导型磁光隔离器。同时 ,这一方法为进一步研究非互易平面光波回路打下了基础     

Synthesis of Organic Dye-Impregnated Silica Shell-Coated Iron Oxide Nanoparticles by a New Method

A new method for preparing magnetic iron oxide nanoparticles coated by organic dye-doped silica shell was developed in this article. Iron oxide nanoparticles were first coated with dye-impregnated silica shell by the hydrolysis of hexadecyltrimethoxysilane (HTMOS) which produced a hydrophobic core for the entrapment of organic dye molecules. Then, the particles were coated with a hydrophilic shell by the hydrolysis of tetraethylorthosilicate (TEOS), which enabled water dispersal of the resulting nanoparticles. The final product was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, and vibration sample magnetometer. All the characterization results proved the final samples possessed magnetic and fluorescent properties simultaneously. And this new multifunctional nanomaterial possessed high photostability and minimal dye leakage.     

萘磺化反应体系中硫酸含量与反应产物的分析

分析了萘磺化反应体系中硫酸含量与萘磺化反应进程的关系，提出以酸碱滴定法测定体系中硫酸含量来精确分析磺化反应进程的方法。     

Magnetite nanoparticles: Electrochemical synthesis and characterization

Magnetite (Fe₃O₄) nanoparticles (NP) with sizes between 20 and 30 nm have been obtained by Fe electrooxidation in the presence of an amine surfactant, which acted as a supporting electrolyte and coating agent, controlling particle size and aggregation during the synthesis. The effect of different parameters on the nature and size of the particles as well as the mechanism of formation of the particles have been studied by different techniques. It was concluded that, under the electrochemical conditions used in this work, the NP mean size was found to be constant at around 20 nm when the electrooxidation current density is increased from 10 to 200 mA cm⁻². However, when the potential is over 6 V, particle size decreases from 30 to 20 nm and metallic iron appears as an impurity. The mechanism of particles formation has being clarified and the critical effect of the distance between electrodes for obtaining magnetic iron oxide nanoparticles has been understood. Finally, the presence of an electrostatic adsorbed surfactant coating the particles allows the functionalization of the particles easily by exchange reaction with biomolecules of interest, which makes this material very promising for future application in biotechnology.     

R_2Fe_(17-x)M_x金属间化合物磁性质的分子场论分析

本文用两格点分子场论（ＭＦＴ）分析了Ｒ２Ｆｅ１７－ｘＭｘ金属间化合物磁性质与温度的关系。得出了ＨＲ（Ｔ）、ＨＦＢ（Ｔ）和ＨＲ（Ｔ）／ＭＦＢ（Ｔ）与温度的关系曲线和分子场系数ｎＲＲ、ｎＲＦ和ｎＦＦ。表明此理论能精确地描述这些化合物磁化的温度关系     

核磁共振岩石物性录井技术新进展

核磁共振岩石物性录井技术的最新进展是核磁共振岩屑岩心分析仪NMR-2M。文章简介了该仪器与PK仪、核磁测井仪的差别,介绍了NMR-2M核磁共振分析仪的主要特点、功能和技术指标,通过应用实例阐述了孔隙度、饱和度等岩石物性参数检测与计算方法,分析了T1和T2谱对不同流体和不同岩性的反映特征。随着此项技术研究的深入和广泛应用,定会使岩石物性录井技术向更高层次发展。     

辐射固化的国际现状——第一届亚洲地区国际辐射固化会议简介

辐射固化技术是辐射加工技术的分支,八十年代以来发展迅速,年增长率在10％以上。用辐射固化的产品种类很多,而磁性介质,隔离涂层,陶瓦瓷砖的装饰面,石膏板装饰表层、印刷板、光纤保护层,电子技术、蚀刻技术、压敏粘合剂等等。实现辐射固化首先要考虑好有关的化学问题。为发展辐射固化技术也应介绍UV/EB固化的安全操作、工业操作规程及专利法等,有关该领域的设备及工业获得很大的进展。     

ANALYTICAL TEMPERATURE DISTRIBUTION FOR MULTIDIMENSIONAL BODIES EXPOSED TO A CONSTANT SURFACE HEAT FLUX

For many decades, solutions for transient temperature distributions in multidimensional objects were determined by combining as a product the solutions of one-dimensional objects necessary to delimit the contour of these multidimensional objects. These product solutions are usually restricted to two types of boundary conditions: a constant wall temperature and a constant heat transfer coefficient

This paper considers the case of an object exposed to a constant surface heat flux. It is shown that when the surface of multidimensional object is submitted to a constant heat flux density, its temperature distribution can be obtained by the simple addition of one-dimensional temperature distributions. Only three one-dimensional solutions are necessary to solve all possible multidimensional problems. These are the solutions for a semi-infinite slab, an infinite plate and an infinite cylinder. The equations describing the temperature profile within each of these one-dimensional objects are presented as well as their graphical representations in a generalized form for rapid determination of temperatures.