Chemical composition and antioxidant activity of essential oil from Magnolia grandiflora L. seed

The chemical composition and antioxidant activity of Magnolia grandiflora L.seed essential oil were examined.By combining gas chromatography and mass spectrometry (GC-MS),16 types of compounds were identified,including 40.91% oxygen-containing terpene derivatives,19.51% terpenes,13.97% esters,13.05% nitrogenous compounds,and 3.64% acids.Its capability of removing hydroxyl free radical was lower than that of V c,but it was closer to V c with increasing concentration.In cell experiment,all essential oil concentration (6.9,13.8,27.7,55.5,111.0,and 222.0 g/mL) groups increased cell proliferation by 26% or more (26.0%,38.8%,44.8%,40.2%,35.8%,and 30.4%,respectively).In rat experiment,the SD rats group showed an at least 38% rise (38.62%,61.68%,and 62.86%,respectively) in glutathione-peroxisome (GSH-Px)activity,which is more than 24% reduction (29.56%,24.30%,and 36.93%) in malondialdehyde (MDA) content,and no significant difference in SOD activity was found.The results show that the essential oil had strong antioxidant activity,without dose effect within the concentration range.     

Target estimation using MIMO radar with multiple subcarriers

This paper analyzes the effect of waveform parameters on the joint target location and velocity estimation by a noncoherent multiple input multiple output (MIMO) radar transmitting multiple subcarriers signals. How the number of subcarriers influences the estimation accuracy is illustrated by considering the joint Cramer-Rao bound and the mean square error of the maximum likelihood estimate. The non-coherent MIMO radar ambiguity function with multiple subcarriers is developed and investigated by changing the number of subcarriers, the pulse width and the frequency spacing between adjacent subcarriers. The numerical results show that more subcarriers mean more accurate estimates, higher localization resolution, and larger pulse width results in a worse performance of target location estimation, while the frequency spacing affects target location estimation little.     

潘二矿煤系高岭岩脱除Fe_2O_3工艺的研究

本文通过对潘二矿煤系高岭岩脱杂工艺实验，认为较佳脱杂效果的工艺条件为焙烧温度430℃，浸出温度120℃，盐酸浓度20％，浸出时间120min。     

5种瓢虫酯酶同工酶种间及种内变异的比较研究

采用聚丙烯酰胺垂直板凝胶电泳的方法分析了５种瓢虫、异色瓢虫４个型及七星瓢虫个体的酯酶同工酶．结果表明，种间的酶谱差异明显，每个种都有自己独特的谱型，彼此易于区分；异色瓢虫型间的主带酶谱相似，但总酶带数差异较大；七星瓢虫个体间的酶谱差异较小．     

智能化数字用户环路倍增系统

利用语音压缩技术和ＩＳＤＮＵ接口实现的数字用户环路倍增设备，可在一对用户线上传输多路高质量的话音或数据。介绍了该系统的技术基础、传输结构和软硬实现及其监控管理功能。     

露天矿山铲-车优化配置研究

本文推导了一般露天矿山铲—车优化配置的数学模型表达式，并以峨眉水泥厂矿山为例进行了优化配置计算。优化结果表明本文方法是有效的。     

应用Z-80微型计算机进行气相色谱仪实时数据处理——色谱峰的定量计算

本文描述了一个色谱实时数据处理软件的算法.将一系列色谱峰的起点与终点连接起来构成基线.峰起点与终点的确定采用相继5点的斜率比较法.两个重叠峰的谷点仅当它低于其相邻两个峰起点与终点之连线时才被考虑画入基线.重叠峰的分割一般用垂线法,在小峰骑大峰的情况下用切线法.峰面积积分用龙贝格法,计算机数据处理的结果与剪纸称重法作了比较,由此证实了前者的准确性.     

一种动态系统稳态优化的抗干扰调优方法

为解决存在干扰情况下的功态系统稳态调优问题,提出了一种新的目标函数及其梯度的辨识方法,并以此给出了抗干扰调优方案。理论分析和仿真结果表明:该法可在较强的输入动态扰动和外干扰下,自动移动工作点至最优点,并具有最优点跟踪性能。     

太原市煤烟型大气污染现状及治理对策

本文分析了太原市燃煤造成大气污染的严重现状及其原因，对煤炭燃烧前、燃烧过程以及烟气排放三个阶段的除尘脱硫提出了治理对策。     

IIS服务器与Foxpro数据库的互连及应用

主要讨论了IIS（InternetInformationServer）服务器与Foxpro数据库的互连技术．阐述了这一技术在实现Internet网上访问Foxpro数据库中的运行机制．目前这一技术已成功地应用于改造镇江海关远程报关系统，实现了在Foxpro环境下的C／S工作方式，显著提高了运行速度．