超临界流体分离与NMR联用技术及其应用

本文重点描述了SFC－NMR和SFE－NMR联用装置的特点及其探头设计,举例说明了它们的几种典型应用,分析比较了超临界流体分离和NMR联用系统与HPLC－NMR联用系统的特性,并讨论了超临界流体分离与NMR联用技术的发展前景。     

超临界流体CO2萃取中药有效成分的抗氧化性的分光光度法研究

利用超临界流体二氧化碳萃取技术提取中药虎杖、大黄、炒白术中黄酮类化合物。在pH8．2的HCl—tris缓冲溶液中利用邻苯三酚自氧化法测定提取物对超氧阴离子自由基的消除作用。用茜素紫作显色剂的分光光度法在pH9．0的HCl—tris缓冲体系中测定中药提取物对Co^2 H2O2体系所产生的羟基自由基的消除作用,并对实验条件进行了探讨。实验结果表明,3种中药提取物对自由基都有消除作用,其中虎杖的效果最好。     

超声振动车削装置设计

在切削加工领域，提高加工精度方法很多，其中一个非常重要的研究方向在于努力减小切削过程中的切削力和切削热。超声振动切削技术在降低切削力和切削热方面有重要的作用，可以较好地解决难加工材料、难加工零件以及精密加工等方面的一些工艺问题。为了推广应用这项新技术，文章基于超声振动切削理论，设计了一套超声振动车削装置，为实现黑色金属薄壁零件的精密加工提供了新的途径。     

超临界二氧化碳萃取磷脂的工艺研究

建立了用超临界二氧化碳萃取法从粗磷脂中萃取纯化磷脂的方法。考察了影响油脂萃取率的因素,采用正交实验确定了最佳萃取条件:萃取压力为30MPa,萃取温度为55℃,萃取时间为2h。大豆、葵花和胡麻三种磷脂得率分别为:88.5%、76.5%及79.2%,含磷量分别为:3.83%、2.62%及2.90%。     

超声探伤综合实验装置的设计与时间分辨率研究及其应用

利用超声探伤原理,对超声探伤实验装置进行了设计与创新,对超声探伤定位的时间分辨率问题进行研究,还探讨了其应用的有关技术.     

超声场强化超临界CO2萃取除虫菊酯的初步研究

本文以除虫菊花中的除虫菊酯萃取为对象,研究用超临界CO2对其萃取时,施加超声场对萃取物降解及萃取速率的影响.结果表明,在实验范围内施加超声场(200kHz,200W电功率)没有引起超临界CO2流体"空化",从而没有使易分解组分除虫菊酯降解;施加超声场可以提高除虫菊酯的萃取速率,且对萃取速率的影响比用水为共溶剂强,在实验范围内,萃取优化工艺条件为萃取压力(20MPa);施加超声场(200kHz,200W电功率);萃取温度(40℃);添加共溶剂水(0.5ml水/g干花);CO2流量(2.0L·min-1).     

二氧化碳超临界流体的管内对流换热研究

随着自然工质ＣＯ２研究的进一步发展,系统中气体冷却器的换热问题越来越受到人们的重视,这是因为高的换热效率是提高系统ＣＯＰ的重要因素．本文首先阐明了超临界流体换热研究的处理原则和分类方法,并重新定义了ＣＯ２临界区范围．利用修改的 ＢＷＲ方程计算得出了 ＣＯ２临界区的物性变化规律,并分析了获得超临界换热关联式的理论求解方法．最后,建立了超临界ＣＯ２管内冷却过程的数学模型,为求解其换热规律提供了方法和依据．     

地质样品中有机物的超临界萃取研究

建立了以CO2为超临界流体的超临界萃取地质样品中有机物的分析方法,讨论和优化了超临界萃取条件,测定了茂名油页岩中的n-C13-n-C34,并与索式抽提结果作了对比,该方法测定茂名油页岩中的n-C15-n-C34链烷烃,相对标准偏差为（n=4)4.9%-23.8%,n-C13的相对标准偏差为9．2％（n=4),而传统经黄的索式抽提法测得的n=C15-n-C34链烷烃的相对标准偏差为11．2％－37．7％（n=4),n-C13的相对标准偏差为46．4％（n=4),本法与传统方法相比,具有高效,无热降解,无毒,选择性好,精密度好等优点,可直接用于GC,GC－MS的测定。     

超临界流体黏度的拉曼光谱测量方法研究

超临界流体黏度的测量对于工业应用具有重要意义。本文利用流体的拉曼光谱随压力的变化关系,基于泊肃叶流动规律,提出超临界流体黏度的非接触式光学测量方法。首先,对甲烷及其混合物、二氧化碳及其混合物的拉曼光谱随压力的变化规律作综述分析,分析表明可以利用甲烷及其混合物的拉曼光谱较为精确地获取体系压力,但利用拉曼光谱精确测量二氧化碳及其混合物压力的方法有待进一步研究。接着,对测量系统作理论设计和灵敏度分析。测量系统由储气罐、可控压力的高压注射泵、温控平台、毛细管阵列和拉曼光谱仪等部件组成,毛细管阵列进出口压力变化显著,用于测量甲烷及其混合物的黏度具有较高灵敏度。     

Extraction of linear furocoumarins from Ammi Majus seeds by means of supercritical fluid extraction and supercritical fluid chromatography

A method of supercritical fluid extraction of the main furocoumarins (bergapten, xanthotoxin, and isopimpinellin, compounds used as photosensitizers in PUVA therapy) from seeds of apiaceous plant Ammi Majus was developed. A technique for analyzing the composition of extracts and for isolating individual furocoumarins with the help of supercritical fluid chromatography was proposed.     

The dual-frequency method for ultrasonic assessment of skeletal system

The article is a review of the new dual-frequency method in axial bone quantitative ultrasonometry for assessment of changes in cortical bones in osteoporosis. The method is based on the use of two frequencies for the generation of flexural and longitudinal ultrasonic waves, which opens possibilities for differential diagnostics of changes in various components of the state of the skeletal system, such as cortical layer thickness, porosity, and elastic properties of tissue. The axial scanning and composition of two-dimensional acoustic profiles of bones are carried out with the purpose of using topographic variations in the acoustic properties for diagnostics of the state of a bone. Results of laboratory and clinical tests of Bone UltraSonic Scanner (BUSS) developed in Artann Laboratories on the basis of the stated principles are presented. The sensitivity of measured characteristics to progression of osteoporosis and the detectability of early changes in bones related to this disease are shown.

     

Ultrasound assisted supercritical fluid extraction of oil and coixenolide from adlay seed

Oil and coixenolide are important components of adlay seed (Coix lachrymal-jobi L. var. Adlay) with many beneficial functions to human health. In this work, a novel extraction technique--ultrasound assisted supercritical fluid extraction (USFE)--was studied. Effects of operating conditions on the extraction, including extraction temperature (T), pressure (P), time (t), CO(2) flow rate (F) and ultrasonic power (I) were investigated. There are optimum temperatures which gives the maximum extraction yields (EYs) for the supercritical fluid extractions with and without ultrasound. The effect of pressure on EYs for is similar to that of pressure on CO(2) density. Based on the yield of extraction, the favorable conditions for supercritical fluid extraction (SFE) were: T at 45 degrees C, P at 25 MPa, t at 4.0 h and F at 3.5L/h. While ultrasound was applied as in USFE, the following parameters were preferred: T at 40 degrees C, P at 20 MPa, t at 3.5h and F at 3.0 L/h, respectively. The results show that supercritical fluid extraction with the assistance of ultrasound could reduce the temperature, pressure, CO(2) flow rate, as well as time used in the process. Compared with SFE, USFE could give a 14% increase in the yield for extracting oil and coixenolide from adlay seed with less severe operating conditions.     

筒仓效应观测仪的设计及其应用

设计并制作了观测静态颗粒物质筒仓效应的实验系统,应用该装置研究了筒仓效应的尺寸依赖性.实验结果表明:圆柱形容器中的颗粒物质对于容器底部的饱和压力依赖于容器直径的3次方,而改变填入颗粒的直径时则饱和压力并无明显改变.     

High-power ultrasonic system for the enhancement of mass transfer in supercritical CO2 extraction processes

Oil is an important component of almonds and other vegetable substrates that can show an influence on human health. In this work the development and validation of an innovative, robust, stable, reliable and efficient ultrasonic system at pilot scale to assist supercritical CO₂ extraction of oils from different substrates is presented. In the extraction procedure ultrasonic energy represents an efficient way of producing deep agitation enhancing mass transfer processes because of some mechanisms (radiation pressure, streaming, agitation, high amplitude vibrations, etc.).A previous work to this research pointed out the feasibility of integrating an ultrasonic field inside a supercritical extractor without losing a significant volume fraction. This pioneer method enabled to accelerate mass transfer and then, improving supercritical extraction times. To commercially develop the new procedure fulfilling industrial requirements, a new configuration device has been designed, implemented, tested and successfully validated for supercritical fluid extraction of oil from different vegetable substrates.     

双频回旋管内置准光模式变换器设计

回旋管一般使用准光模式变换器实现高阶腔体模式到高斯波束的转换。结合标量衍射理论、KS迭代算法、几何光学、最小均方法等方法设计了工作频率为140 GHz（TE_{24, 9}）和105 GHz（TE_{18, 7}）的双频准光模式变换器。仿真结果显示所设计的准光模式变换器工作频率为140 GHz（TE_{24, 9}）时能量传输效率99.0%、高斯含量99.7%,工作频率为105 GHz（TE_{18, 7}）时能量传输效率97.3%、高斯含量98.0%。能够满足MW级双频回旋管的应用需求。

     

ITER CC导体测试装置数据采集系统的设计与应用

系统介绍了ITER CC性能认证超导导体测试装置数据采集系统的硬件设计.该系统可以对温度、压力、流量、液位、电流、磁场、电阻、电压降等物理量进行测量,并能根据实际需要进行系统扩展.另外还对基于VC++6.0编程环境下的数据采集系统的程序设计进行了介绍.通过对软件和硬件的集成调试,该系统实现了高速高精度的数据采集.     

Fluid phase equilibrium studies on model substances for supercritical fluid extraction with CO2 up to 100 MPa

Abstract

Multicomponent fluid phase equilibrium data are of increasing interest for applications in Supercritical Fluid Extraction (SFE) where compressed supercritical gases are used for the extraction of low-volatile substances (e.g. caffeine from coffee and tea, hops etc.). Sometimes so-called moderator substances have to be added in order to increase solvent power and/or selectivity. Systematic measurements on a four-component system of the type CO₂ + fatty alcohol (e.g. 1-do-decanol) + alkane (e.g. hexadecane) as a function of the amount of moderator added were performed at 393 K and at pressures from 10 to 100 MPa in an analytical high-pressure cell. Separation factors calculated from the p,T,w/,w, “data are presented and discussed.     

The radioprotective and prophylactic properties of biologically active substances prepared by supercritical fluid extraction from pine shoots

The radioprotective properties of a substance from pine shoots prepared by supercritical fluid extraction with carbon dioxide were studied for a model of an experimental bone-marrow radiation sickness form. Experiments were performed for white nonlinear mice. The CO₂ extract of pine shoots was shown to possess radioprotective properties. The extract was subjected to pre-clinical tests for Wistar line male rats with respect to its antiatherogenic and antioxidative action in the creation of experimental hyperlipemia.