Pressure infiltration of Al and Al-12 wt% Si alloy into compacts of SiC and oxidized SiC particles

Oxidizing SiC particles is a common practice in the fabrication of SiC/Al composites through direct mixing of the liquid metal and the ceramic particles. This practice is addressed to reduce the reaction between the two materials. In a previous work it was concluded that oxidizing SiC particles scarcely affected the threshold pressure for infiltration of pure Al into compacts made of those particles. In this work we present a detailed study of this problem for infiltration of pure Al and the eutectic Al-Si alloy. Our results indicate that oxidizing of SiC particles does not affect significantly either the threshold pressure or the infiltration kinetics. This conclusion is equally valid for both pure Al and the eutectic alloy.     

一个地下水流及溶质迁移模拟的图形化方案

本文介绍在地下水饱和系统中，对地下水流和溶质迁移模拟进行计算机图形化处理的方案。     

高流速双室床节水效果评价

高流速双室床(HDCB)是我国自主开发的一项水处理新技术。陕西某热电厂1年多的运行结果表明,其自用水率仅为3.2%,远低于反渗透(33%)及其他离子交换技术(10%)。HDCB自用水率低是由其结构及运行特性决定的,它具有周期制水量大,再生步骤少,再生过程用水量少,大反洗(清洗)次数少等特性,是目前化学水处理技术中节水效果最好的一种技术。     

基于ERDAS 9.1/ER mapper软件快速制作航空遥感DOM的方法

快速制作航空遥感正射影像图(DOM),不仅能够及时获得动态目标的变化信息,而且可以对突发事件进行及时的动态监测,为现场应急指挥提供第一手翔实的图像资料.利用LPS ERDAS 9.1(含LPS模块)、ER mapper遥感图像处理软件,对基于机载POS系统、POSPAC软件数据进行研究,提出一种快速制作正射影像图的方法,并对黄海浒苔地区航空遥感影像进行了验证,结果表明,快速制作的黄海浒苔正射影像达到了预期的精度指标,取得了较好的效果.     

提高品种钢质量推动精益化管理

介绍了湘钢以82B为代表的品种钢质量控制方面的作法与经验,以及以其为切入点,全面推行产品质量的精益化管理模式.     

Rapid and Sensitive Liquid Chromatography-Tandem Mass Spectrometry for Quantification of Glycyrrhetic Acid in Human Plasma

A simple, rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) for the determination of glycyrrhetic acid in human plasma with ginsenoside Rh2 as internal standard was developed and validated. The plasma samples were prepared via liquid-liquid extraction with ethyl acetate. Chromatographic separation was accomplished on a Venusil MP-C18(50 mm×2.1 mm, 5μm i.d.) column at 25℃. The mobile phase consisted of acetonitrile/5 mmol·L-1 ammonium acetate(10:90, volume ratio) at a flow rate of 0.4 mL/min. Negative electrospray ionization was utilized as the ionization source. Glycyrrhetic acid and internal standard were determined via the mutiple reaction monitoring of precursor→production ion transitions at m/z 469→425, 409 and m/z 621→161,respectively. Each sample was chromatographed within 2.5 min. The lower limit of uantification was 0.50 ng/mL for 200 μL of plasma sample and the linear range was from 0.50 ng/mL to 800 ng/mL. The intra-and inter-day precisions were less than 8.76% in terms of relative standard deviation(RSD), and the accuracy was within a range of -3.25%-1.32% in terms of relative error(RE). The method was successfully applied to the pharmacokinetic studies of glycyrrhetic acid in healthy male Chinese volunteers after a single oral administration of 75 mg of glycyrrhizin.     

我国有机食品的现状及发展趋势

介绍了有机食品的特点及对人与自然和谐发展的作用,并概述了我国有机食品的发展现状及趋势.     

锚杆锚索联合支护在大断面巷道中的应用

分析了沈阳煤业集团西马煤矿北二区的地质条件,根据生产实际对北二区回风上山掘进工作面的支护选择锚杆锚索联合支护方式,确保了大断面巷道支护的安全。     

K52合金及其涂层的涂盐热腐蚀行为

研究了合金及其涂层的热腐蚀行为,测定了它们的氧化动力学曲线。用扫描电镜和电子探针观察了合金及涂层腐蚀后的表面形貌和横截面显微组织。结果表明:溅射K52纳米晶涂层在含有NaCl的盐中腐蚀10 h,氧化膜就大面积剥落,涂层遭受很大的破坏。而铸态合金腐蚀50 h后,产生已基本连续的内氧化铝层,这层氧化铝对阻止O、S和Cl的进入起到一定的作用,提高了合金的抗氯盐腐蚀。