化学束外延

本文介绍了化学束外延(CBE)的发明和发展,论述了CBE的原理和设备。文中还介绍了最近提出的一种生长机理。     

Pyrolysis of tertiarybutylphosphine at low pressure

The pyrolysis of tertiarybutylphosphine (TBP) has been studied in the low pressure conditions used for chemical beam epitaxy (CBE). The pyrolysis studies were carried out in low pressure reactors of two different configurations, one of which is a cracker cell designed for use in a CBE system. The reaction products were studied using a quadrupole mass spectrometer. The products observed are accounted for by a reaction mechanism involving homolysis of the parent TBP molecule to produce PH₂ and C₄H₉ radicals. These undergo subsequent reactions to form the stable products C₄H₈, PH₃ and H₂, with smaller amounts of P and P₂ being produced. The production of the sub-hydride PH₂ using this cracker cell design indicates that the use of partially cracked TBP may be a promising technique for reducing the amount of carbon incorporated into the growing epitaxial layer.     

基于案例的解释研究

解释是专家系统中一个重要环节,优秀的解释技术可以帮助用户增强使用系统的信心,帮助用户进一步理解系统的推理过程和结果.介绍基于案例解释的相关概念,然后从不同角度对近年来国内外研究进展做出综述与评价,并对基于案例的解释技术做出总结与展望.     

职业教育在人才培养中的个性化教育研究

个性化教育作为培养具有创造性思维能力、表达能力的个性化人才的主要途径，是21世纪各个谋求发展的国家所共同关注的问题。加强职业教育中的个性化教育，要明确个性化教育目标，更新个性化教育理念，建立综合职业能力课程观，掌握先进的教育方法，建立新型的教育管理体制，改革教学评价体系和评价方法，充分发挥校园文化对学生个性培养的功能。     

CBE教改在职业教育中的应用

通过矿山电气化专业CBE教改过程 ,系统介绍了CBE教改实施情况并提出了自己的建议     

Preparation of sharp-melting hard palm midfraction and its use as hard butter in chocolate

Preparation of hard palm midfractions (PMF) and its use as a cocoa butter equivalent ingredient were studied. Hard PMF is obtained by multistep fractionation of palm oil involving dry fractionation (DF) and/or solvent fractionation (SF), usually using hexane or acetone. From our experience, in acetone, a polar solvent, symmetrical 1,3-disaturated triacylglycerols tend to selectively crystallize more than nonsymmetrical 1,2- or 2,3-disaturated triacylglycerols, making it suitable for obtaining the solid midfraction. Unfortunately, triacylglycerols are very soluble in hexane, and temperatures at least 15 degrees lower than those required for acetone must be used for equivalent crystal yields. On the other hand, DF is a less expensive and safer process. Thus, multistep fractionation combining DF and SF using acetone was developed to achieve sufficient removal of high-melting components, and further enrichment of 1,3-dipalmitoyl-2-oleoylglycerol and the hard PMF was obtained by triple-step fractionation of palm olein or double-step fractionation of soft PMF. Compared to conventional hard PMF, this hard PMF had a steeper melting curve and better snapping and sharp-melting qualities when used in chocolate. Heat resistance of the hard PMF chocolate was similar to the conventional hard PMF chocolate, and its bloom resistance could be improved by adding polyglycerol fatty acid esters.     

CBE理论对我国普通高校体育教学具有可借鉴性

CBE理论体系目前在北美是比较流行的一种教学模式，该体系着重是以培养学生能力为中心的教学理论。他与我国普通高校体育教学所追求的目标与宗旨相一致，因而在高校体育教学中具有一定的可借鉴性。     

几种真菌油脂的分析

在实验室条件下培养提取所得的几种真菌油脂经水解后进行薄层层析 ,结果表明油溶性成分因菌种而异 ;脂肪酸分析表明在不同培养条件下菌种脂结构也不同 ;对土生假丝酵母在优化条件下合成的类可可脂经甘三酯组成测定和差示扫描量热法分析 ,证明了此条件下所产的类可可脂是较理想的类可可脂     

CBE模式在电厂锅炉运行岗位培训中的应用

阐述CBE模式在电厂锅炉运行岗位培训中的应用技术 ,分析了CBE模式与传统培训模式在目标、内容、形式、评价标准、专业划分以及培训资金投入产出比等方面的优势 ,简要介绍了CBE模式的培训产品———电厂锅炉运行多媒体培训软件