超临界流体技术应用进展

超临界流体技术具有许多传统技术所没有的快速、高效、低能耗、污染少等优点。本文综述了其在分离、分析、材料制备和作为反应介质等方面的应用现状。     

Simple yield stress fluids

Recent years have seen a flurry of research on yield stress fluids, approached from different perspectives (physicochemical, rheological and fluid mechanical), considering different length scales and timescales, using a range of tools: experimental, computational and analytical. In this context, it has been common to denigrate the simple models of yield stress fluids for their various acknowledged deficiencies and proffer improved models. Here, we push back, in defence of the century-old simplicity, exploring what is new and useful and what these models have given in the past few decades.     

聚合物电流变体

本文概述了电流变体的发展概况，电流变机理、电流变效应的影响因素及聚合物电流变体的研究现状，并介绍了电流变化的组成春在机械制造、自动控制等领域的应用前景。     

Investigation of pituitary adenylate cyclase activating polypeptide in human gynecological and other biological fluids by using MALDI TOF mass spectrometry

Pituitary adenylate cyclase activating polypeptide (PACAP) is a multifunctional and pleiotropic neuropeptide. PACAP has diverse effects in the endocrine system, among others, it plays important roles in oogenesis, implantation and development of the nervous system. However, it is not known whether PACAP is present in the fluids of the human reproductive organs. The aim of the present study was to determine, by means of mass spectrometry and radioimmunoassay, whether PACAP is present in human amniotic fluid, ovarian follicular fluid and cervico-vaginal fluid. Samples were obtained from healthy adult volunteers. Our MALDI TOF and MALDI TOF/TOF spectrometry results show that PACAP38 is present in all of the follicular fluid samples, and PACAP-like immunoreactivity was also measured by radioimmunoassay. However, we did not find the characteristic peak representing the unmodified 38 amino acid form of the peptide in normal cervico-vaginal smear and amniotic fluid samples. Furthermore, we analyzed other body fluids for comparison, such as human nasal fluid, saliva and aqueous humor. PACAP was not found in these latter samples. In summary, the present study provides evidence for the presence of PACAP in human follicular fluid, suggesting a role in oocyte function, but determination of the exact physiological significance awaits further investigation.     

可调变流体与绿色化工过程

介绍了可调变流体特性及其在绿色化工过程中的应用。重点介绍了利用超临界流体(主要是超临界C02)、亚临界水和气体(主要是CO2)膨胀的流体这三类可调变流体进行绿色化工过程设计的特点与途径。     

二氧化硅负载胺丙基硅烷电流变流体

研究用二氧化硅负载胺丙基三乙氧基硅烷［ＮＨ２（ＣＨ２）３Ｓｉ（ＯＥｔ）３］作为分散颗粒，制备无水型的电流变（ＥＲ）流体．考察电场强度（Ｅ）、剪切速率（γ·）、分散颗粒含量、分散介质种类以及极性小分子等因素对ＥＲ流体流变性能的影响．结果发现，以硅油为分散介质，含分散颗粒为１５％（ｇ／ｍｌ）的流体，不添加任何活化剂，在γ·为８０６６ｓ－１时，Ｅ从０升至１６６６ｋＶ／ｍｍ，流体的表现粘度（ηａ）从０３９６Ｐａ．ｓ增大到１６６６８Ｐａ．ｓ．γ·提高，ηａ降低．分散颗粒含量增加，ηａ增大．用硅油作分散介质，ＥＲ效应比用矿物油或石蜡油显著．加入极性小分子苯胺，可以增强流体的ＥＲ效应，但随着苯胺含量增多，漏电流密度也增大．     

化学流体沉积法制备纳米复合材料研究进展

化学流体沉积(Chemical Fluid Deposition,CFD)是近年来新发展的一种材料制备方法。与化学气相沉积(CVD)等其它传统方法相比,具有很多突出优点。本文在论述CFD方法的原理、特点及典型反应装置的基础上,重点就CFD的研究现状、优势以及目前尚存在的不足进行了分析讨论,指出了CFD在制备纳米复合材料中的作用、发展前景和今后应该注意解决的关键问题。     

超临界流体色谱流程设计及其应用

本文设计了多功能超临界流体色谱流程,流程中包括毛细管/微填充柱SFC,GC,计算机控制温度、压力、密度及信号采集、处理,配置有超临界流体萃取池,解决了超临界流体色谱分流口易堵问题。利用该流程,将石腊、DC-200气相色谱固定相、黄油、蜂蜡、救心油、红花油等样品进行超临界流体色谱分离。     

Supercritical fluid extraction of Kava lactones from Kava root and their separation via supercritical fluid chromatography

Summary Seven Kava lactones were extracted from Kava root using both pure and 15% ethanol modified CO₂. Most of the Kava lactones were extracted employing 100% CO₂ with an efficiency greater than 90% relative to conventional solvent extraction using organic solvents. Extraction efficiency did not increase significantly when using 15% ethanol-modified CO₂ as an extraction fluid. Separation of extracted Kava lactones was obtained using various packed columns and methanol-modified CO₂. An optimized separation was achieved using either an amino or protein C₄ column at 125 atm and 80°C. Semi-preparative separation of Kava lactones was also obtained using two columns connected in series.     

金属离子的超临界流体萃取技术的进展

超临界流体萃取技术在分离方面发展迅速,应用前景十分广泛。文中综述了超临界流体技术的萃取机理及对金属离子萃取的研究。     

磁流变液组分对其沉降性影响的研究进展

磁流变液是一种形态和性能受外加磁场控制的新型智能材料。在汽车、建筑、医疗、航空航天多种领域具有重要的应用价值,但磁流变液沉降性问题一直是影响其广泛应用的难题。因此,首先从载液、磁性颗粒和添加剂三方面出发,简要回顾了近几年在磁流变液沉降性方面的研究,指出了影响磁流变液沉降性的因素主要有：载液的粘度、磁性颗粒的形状和尺寸、磁性颗粒与载液之间的密度差、添加剂的种类与添加量等。并给出了有效提高磁流变液沉降性的可行策略,最后从磁流变液的沉降现象与应用方面对沉降性研究进行了展望。     

The Research on the Principles of Component of Magnetorheological Fluid Selecting and Its Mechanism

Because of its extensive applying prospect, magnetorheological fluid and its device have been concerned by many domain,but the lack of good magnetorheological fluid that can be used in real engineering is hindering the developing of this technology. Firstly, from the direction of the mechanism of rheologic and its performance objective, the principles of components of magnetorheological fluid selecting and their affects on fluid’s performance are studied. Secondly, the technology of disperse is researched. At last, the performance of a kind of magnetorheological fluid that made by the above principles is introduced.     

Recent advances in sample introduction for supercritical fluid chromatography

New strategies for sample introduction in supercritical fluid chromatography are reviewed. Both open tubular and packed column systems are examined as the injection demands of each column type are addressed. In addition to advances made in solvent injection methods, supercritical fluid extraction (SFE) is discussed as a solventless injection technique for supercritical fluid chromatography.     

Augmented van der Waals equations of state: SAFT-VR versus Yukawa based van der Waals equation

Performance of the SAFT-VR equation of state developed for the hard sphere based simple fluids, namely the square-well, Sutherland and Yukawa fluids, is examined by comparing its results with simulation data and an augmented van der Waals (vdW) equation based on a Yukawa (Y) reference. Its shown that both for the equilibrium vapor-liquid data and data along selected isotherms in the liquid and supercritical fluid phases the vdW(Y) equation provides better results, particularly when going to lower temperatures.     

超临界流体技术在萃取中的应用简介

超临界流体萃取技术具有许多传统技术所没有的快速、高效、高选择性、低能耗等优点,特别是超临界流体的特性是它可以代替高毒有机溶剂做反应介质,符合绿色化学的要求。本文综述了超临界流体的特性,介绍了超临界流体萃取的原理,归纳了超临界流体萃取的应用现状,并介绍了超临界流体的其他领域应用概况。     

自制超临界流体萃取仪操作条件的优化及其应用

超临界流体萃取是近年来发展起来的一种新的分离技术。本文使用自己研制的超临界流体萃取仪对吸附有痕量正构烷烃的Ａｌ２Ｏ３进行萃取，对各种操作条件进行优化。并对卢柑皮及生姜样品进行初步的萃取分析。结果证明该仪器设计合理，具有操作简便、高效、自动化程度高的优点，为复杂样品中痕量组分的萃取分析奠定了基础。     

灌浆理论浅析

详细分析了两种灌浆液体的类型牛顿体和宾汉姆体的力学特征以及二者之间异同和联系,介绍了岩土体结构的基本理论、灌浆的基本理论、渗透灌浆理论机制及内容、劈裂灌浆理论机制及内容、压密灌浆理论机制及内容。     

催化裂化汽油中类型硫含量分布

利用催化裂化汽油中各类硫化物的系统分析方法,对催化裂化(FCC)汽油和重油催化裂化(RFCC)汽油中各类型硫进行了分析测定,碱洗后FCC汽油和RFCC汽油中类型硫的布规律为:硫醇硫和二硫化物硫的含量较少,硫醚硫含量中等,而噻吩类硫的含量最多,占总硫含量的60%以上.     

Exploration and optimization of conditions for quantitative analysis of lignans in Schisandra chinensis by an online supercritical fluid extraction with supercritical fluid chromatography system

An online supercritical fluid extraction with supercritical fluid chromatography system could provide sequential extraction and quantitative analysis of lignans in Schisandra chinensis. Supercritical fluid extraction conditions were optimized at 15 MPa, 50°C, and 4 min with supercritical CO₂ adding 1% methanol; the elution volume and flow rate were set at 6 mL and 2 mL/min to blow extract out of the tank completely. The split‐flow rate was confirmed at 2.5%, which determines injection volume and accuracy of quantitative detection. The factors having negative influences on supercritical fluid chromatography retention in the online system, including sample loading forms and backpressure settings, are discussed in the paper. At last, an extraction‐quantitative method for lignans in Schisandra chinensis was developed, which could be finished within 19.5 min. The total content percentage of four lignans (Schisandrin, Schisandrin A, Schisandrin B and Schisandrol B) in four batches was respectively measured to be 1.42, 1.54, 1.62, and 1.90%.     

The search for reactive peroxides and hydroquinones in an acrylic copolymer blend via supercritical fluid extraction-chromatography

Summary The objective of this work was to extract, identify, and quantify dibenzoyl peroxide (DBPO), N,N-dimethyl-p-toluidine (DMPT), hydroquinone (HQ), and the methylether of hydroquinone (MEHQ) in an ethyl and methyl methacrylate copolymer blend cured at 35°C for two different time periods. The reactivity of BPO, HQ, and MEHQ made working with supercritical fluids most advantageous. Exactly 0.85 gram of cured polymer was placed in a 5 mL extraction vessel. In order to obtain efficient collection of the analyte after supercritical fluid extraction, a solid phase trap (C₁₈) was used. Various polymer samples were cured at different times and then extracted and analyzed. The level of DMPT decreased by 50% (0.22% to 0.12%) as the cure time increased from 30 minutes to 24 hours. The BPO level did not vary with increasing cure time (0.44% vs 0.43%). The MEHQ level could not be ascertained since it was below our detection limit for MEHQ.