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线型缩聚中当量系数及过量分数的新定义及其关系 被引量:3
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作者 郭霖 《大学化学》 CAS 1998年第5期57-59,共3页
提出了一种可适用于任意配比的各类线型缩聚体系、且物理含义明确的当量系数r及过量系数Q的新定义,并给出了两者间的关系。
关键词 缩聚 线型缩聚 当量系数 过量分数 定义
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线型缩聚中过量分数的新定义
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作者 郭霖 《青岛大学学报(工程技术版)》 CAS 1997年第3期14-17,共4页
介绍了线型缩聚产物数均聚合度计算中广泛成立的过量分数Q的新定义
关键词 线型缩聚 高聚物 数均聚合度 过量分数
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手性传感器研究进展 被引量:3
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作者 熊斐 李莉 《有机化学》 SCIE CAS CSCD 北大核心 2018年第11期2927-2936,共10页
手性化合物在不对称合成、生物学和医药学等领域发挥着重要作用,建立快速、灵敏、高选择性的手性分析方法意义重大.手性传感器因其在确定对映体的绝对构型及对映体过量值中具有简单、快速、灵敏和实时等优点,备受研究者的青睐.聚焦于荧... 手性化合物在不对称合成、生物学和医药学等领域发挥着重要作用,建立快速、灵敏、高选择性的手性分析方法意义重大.手性传感器因其在确定对映体的绝对构型及对映体过量值中具有简单、快速、灵敏和实时等优点,备受研究者的青睐.聚焦于荧光传感器、圆二色谱传感器、紫外-可见传感器、核磁传感器和质谱传感器,主要介绍了各种传感器的特点及原理,综述了近年来它们在手性识别中的应用,并展望了手性传感器的发展前景. 展开更多
关键词 手性传感器 手性化合物 手性识别 对映体过量分数 绝对构型
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Recycling of Aluminum from Fibre Metal Laminates
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作者 祝国梁 肖艳萍 +3 位作者 杨永祥 王俊 孙宝德 BOOM Rob 《Journal of Shanghai Jiaotong university(Science)》 EI 2012年第3期263-267,共5页
Recycling of aluminum alloy scrap obtained from delaminated fibre metal laminates (FMLs) was studied through high temperature refining in the presence of a salt flux. The aluminum alloy scrap contains approximately ... Recycling of aluminum alloy scrap obtained from delaminated fibre metal laminates (FMLs) was studied through high temperature refining in the presence of a salt flux. The aluminum alloy scrap contains approximately mass fraction w(Cu) = 4.4%, w(Mg) = 1.1% and w(Mn) = 0.6% (2024 aluminum alloy). The main objective of this research is to obtain a high metal yield, while maintaining its original alloy compositions. The work focuses on the metal yield and quality of recycled A1 alloy under different refining conditions. The NaCI-KC1 salt system was selected as the major components of flux in the A1 alloy recycling. Two different flux compositions were employed at NaC1 to KC1 mass ratios of 44:56 and 70:30 respectively, based on either the euteetic composition, or the European preference. Different additives were introduced into the NaCI-KC1 system to study the effect of flux component on recycling result. Although burning and oxidation loss of the alloying elements during re-melting and refining take place as the drawbacks of conventional refining process, the problems can be solved to a large extent by using an appropriate salt flux. Experimental results indicate that Mg in the alloy gets lost when adding cryolite in the NaCI-KC1 salt system, though the metal yield can reach as high as 98%. However, by adding w(MgF2) = 5% into the NaCI-KC1 salt system (instead of using cryolite) all alloying elements were well controlled to its original composition with a metal yield of almost 98%. 展开更多
关键词 Al-Cu-Mg alloy 2024 A1 RECYCLING CRYOLITE salt flux
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PROJECTION-PURSUIT BASED PRINCIPAL COMPONENT ANALYSIS:A LARGE SAMPLE THEORY
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作者 Jian ZHANG Institute of Mathematics,Statistics and Actuarial Science,University of Kent,Canterbury,Kent CT2 7NF,U.K. Institute of Systems Science,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100080,China 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2006年第3期365-385,共21页
The principal component analysis (PCA) is one of the most celebrated methods in analysing multivariate data. An effort of extending PCA is projection pursuit (PP), a more general class of dimension-reduction techn... The principal component analysis (PCA) is one of the most celebrated methods in analysing multivariate data. An effort of extending PCA is projection pursuit (PP), a more general class of dimension-reduction techniques. However, the application of this extended procedure is often hampered by its complexity in computation and by lack of some appropriate theory. In this paper, by use of the empirical processes we established a large sample theory for the robust PP estimators of the principal components and dispersion matrix. 展开更多
关键词 Dispersion matrices eigenvalues and eigenvectors empirical processes principal component analysis projection pursuit (PP).
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