快速分析香料槟榔片的挥发性组分

采用顶空固相微萃取气质联用(HS-SPME-GC/MS)法分析检测香料槟榔片的挥发性香味组分,探讨萃取时间和萃取温度对所鉴定出的化合物数量及其质量分数的影响,确定固相微萃取的优化条件为:萃取时间30 min,萃取温度60℃。此时槟榔色谱共分离得到35种化合物,可鉴别出29种物质,其主要组分是反式茴香醚(w=25.573%)、己酸(w=17.227%)、肉桂醛(w=11.658%)、4-甲氧基安息香醛(w=4.513%)、十二烷酸(w=4.463%)和己醛(w=3.459%)等。     

中药材良姜挥发性组分分析

通过顶空固相微萃取结合气-质联用技术,分析检测中药良姜的挥发性组分,研究萃取时间、萃取温度对良姜挥发性物质数量的影响。结果表明,当萃取时间为35 min,萃取温度为60℃时共检出53种化学组分,其中52种物质可鉴别。其主要组分是萜烯类化合物(w=40.238%)、桉树脑(w=23.066%)、α-松油醇(w=8.522%)、β-蒎烯(w=3.618%)和莰烯(w=3.001%)等。     

非马尔科夫可修表决系统可靠性数字仿真

本文设计了求解任意非马尔科夫可修表决系统可靠性指标的仿真算法,通过仿真计算可以获得系统任意瞬态可靠性指标。文中给出了几种不同情况的仿真实例。文末对本文算法进行了检验。     

大型随机稀布阵列雷达的脉冲综合方法及其性能

大型随机稀布阵列可以用数量有限且结构简单的天线合成一大孔径雷达天线,以提高雷达的分辨能力。本文在综合脉冲孔径雷达（ＳＩＡＲ）体制基础上研究大型随机稀布阵列雷达的脉冲综合与孔径综合方法及其性能,并给出了计算机模拟结果。     

滚切齿数大于100的质数斜齿圆柱齿轮

介绍了滚切齿数大于１００的质数斜齿圆柱齿轮的调整公式,并介绍了挂轮累加计算法。实践证明,使用这种计算方法能准确地确定挂轮齿数,提高传动链的传动精度。     

Evaluation of Woven Fabrics for Comfort Properties in Children’s Summer Wear

This paper evaluates the comfort properties of eightkinds of woven fabric commonly used for children'ssummer wear in Hong Kong,China.Due to the expan-sion of children's wear market and the quality require-ment for parents,objective and subjective measurementsare the main methods used to evaluate the chosen fabricsfor garment deslgners and consumers as reference. Objective measurement was carried out through ex-periments by means of the Kawabata Evaluation Systemfor Fabrics(KES-F).Experimental tests on fabrics in-clude compression,surface,bending,air permeability,thermal and tensile.Subjective measurement was con-ducted by a market research on consumers' opinions onfabrics for children's summer wear in the form of ques-tionnaire survey.These two ways of measurement onfabrics were analyzed and compared. It was found that Fabric Sample 6 which is com-posed of polyester and cotton fibre has the best perfor-mance in terms of its comfort properties.Besides,Sam-ple 4 composes of rayon and cotton fibre also ha     

Torsional Models of Two - ply Yarn

In this paper,the vector equation of a generaliseddoubly wound helix was derived.Treloar's pliedyarn geometry could be obtained as a special case ofthe generalised doubly wound helix.The shortest fi-bre length around the surface of a helical tube(formed by fibre helices)was determined by apply-ing variational principles.The fibre length as calcu-lated by using Treloar's geometry was compared in-directly with the shortest possible fibre length at dif-ferent levels of yarn deformation when some of Tre-loar's rigid geometrical constraints were relaxed.Anew idea based on non-concentric circles was intro-duced to approximate the fibre helix movement in atwo-ply yarn.A torsional model of two-ply yarnwas developed and the theoretical predictions werecompared with some preliminary experimental re-sults.