概化理论在语言测试新进展中的应用

概化理论是一种发展较晚但功能全面的现代测试理论，能有效地设计、分析和评估测试项目。直到上个世纪八九十年代，Robert Brennan等人开发了GENOVA等一系列应用软件后，概化理论才在心理和教育测量领域的研究中逐渐受到重视，此后，运用概化理论研究实际问题的项目也逐渐多了起来。概化理论与项目反应理论属于不同的理论范畴，它们的基本假设也有很大的差别。     

Rare Earth Doped Polymer Waveguide Materials and Devices

1 Results Rare earth doped waveguide amplifiers and devices have been demonstrated in silica, crystal and other glass hosts. These rare earth doped optical waveguide devices are based on inorganic materials. Many processing steps are required and can lead to long fabrication time and low yield.Polymer materials offer many distinct properties compared to inorganic materials, such as ease of fabrication, low production costs, simple processing steps, and compatibility with micro-fabrication technologies. ...     

Applications of Transition Metals in Organic Synthesis and Polymerization

1 Results Classic oxidants require rigorous control of the experimental conditions added with the problem of lack of selectivity. Catalysis by transition metals with environmentally safe oxidants provides synthetic routes to minimize pollution by giving environmental benign by-products. Fe (Ⅵ) is a powerful and a selective oxidant with Fe(Ⅲ) as a by-product, while hydrogen peroxide is clean with water as the only by-product. Separation of sodium or potassium ferrates requires tedious processes. Associat...