油脂超临界萃取的分离方法研究概况

本文阐述超临界萃取的技术原理及其工艺特点,并介绍利用超临界流体色谱（ＳＦＣ）将油脂类化合物分离分析,对油脂中各种脂肪酸组成与含量的测定。一般都必须经过衍生化,然后用ＧＣ－ＭＳ分离分析,但这种方法不能确定油脂母体与各种脂肪酸的连接关系。本文介绍利用ＣＳＦＣ仪,纯ＣＯ２流体,对油脂类化合物的分离分析。     

加压下混合流体汽液界面张力的分子热力学模型

建立了两个计算近临界点区域混合流体的汽液界面张力统计力学模型：一是将范德华理论１混合规则引入Ｋｉｒｋｗｏｏｄ－Ｂｕｆ纯流体界面张力模型;另一模型是建立在Ｄａｖｉｓ混合流体汽液界面张力模型。Ｄａｖｉｓ模型对单一纯组分流体可还原为Ｋｉｒｋｗｏｏｄ－Ｂｕｆ模型。对２１个纯组分流体的界面张力进行了关联,得到模型的分子参数,对纯流体平均标准差为１２０μＮ／ｍ,温度范围从常温到临界点,压力范围从常压到临界压力。应用两种模型计算了二氧化碳／丁烷混合体系的界面张力。     

利用最小作用量原理建立比拟关系的研究

利用最小作用量原理建立了理想流体平面势流与保守力场中质点平面运动之间的比拟关系。     

离线超临界流体萃取和气相色谱/质谱联用对实验室内空气中气相有机污染物的测试

通过团体吸附剂富集，再用超临界ＣＯ２脱附后用气相色谱及质谱技术对实验室内空气中气相有机污染物进行了考察。文中对采样和萃取条件进行了优化，并与热脱附所得结果做了比较。结果表明在２２ＭＰａ，８０℃时，用甲醇改性的超临界ＣＯ２进行萃取的结果优于热脱附法。该法鉴定出气相有机污染物中５２个组分，占色谱峰总面积的９９．６％。     

超临界流体萃取法脱除云南小粒咖啡豆中咖啡因的研究及评香模型初建

 应用超临界流体萃取技术（ＳＦＥ）脱除云南小粒咖啡豆中的咖啡因，取得较好效果；采用顶空气相色谱、色／质谱手段，对ＳＦＥ处理前后的咖啡中的香味成分进行了对比分析，提出了一种用于进行咖啡香味鉴评的模型。     

SHAPE MEMORY EFFECT OF PU IONOMERS WITH IONIC GROUPS ON HARD-SEGMENTS

SMPU （shape memory polyurethane） non-ionomers and ionomers, synthesized with poly（c-caprolactone） （PCL）, 4, 4＇-diphenylmethane diisocyanate （MDI）, 1,4-butanediol （BDO）, dimethylolpropionic acid （DMPA） were measured with cyclic tensile test and strain recovery test. The relations between the structure and shape memory effect of these two series were studied with respect to the ionic group content and the effect of neutralization. The resulting data indicate that, with the introduction of asymmetrical extender, the stress at 100% elongation is decreased for PU non-ionomer and ionomer series, especially lowered sharply for non-ionomer series; the fixation ratio of ionomer series is not affected obviously by the ionic group content; the total recovery ratio of ionomer series is decreased greatly. After sufficient relaxation time for samples stretched beforehand, the switching temperature is raised slightly, whereas the recovery ratio measured with strain recovery test method is lowered with increased DMPA content. The characterization with FT-IR, DSC, DMA elucidated that, the ordered hard domain of the two series is disrupted with the introduction of DMPA which causes more hard segments to dissolve in soft phase; ionic groups on hard segment enhance the cohesion between hard segments especially at high ionic group content and significantly facilitate the phase separation compared with the corresponding non-ionomer at moderate ionic group content.     

无保护流体室温燐光法测定吲哚-3-丁酸的研究

在仅以碘化钾为重原子微扰剂、亚硫酸钠为除氧剂及无任何保护性介质存在的水溶液中 ,吲哚_3_丁酸 (IBA)能发射很强的室温光 (RTP) ;详细研究了分析测定条件及有机溶剂对RTP的影响 ;在最大光波长λex/λem =281/447nm处 ,光强度与IBA浓度在2.0×10 -7～1.0×10 -5mol/L范围内呈良好的线性关系 ,检出限4.3×10-8 mol/L ;方法直接用于强化水样和土壤中IBA的测定 ,回收率96 %～104 % ,相对标准偏差2.37 %～3.97 %。     

扫描探针纳米加工技术的现状与发展趋势

介绍了扫描探针纳米加工技术的基本原理、应用前景和最新进展 ,并讨论了该技术的发展趋势     

纳米级TiO_2粉体的制备研究Ⅰ.pH值的影响

采用无机盐作为前驱物，利用溶胶凝胶超临界流体干燥（ＳＣＦＤ）法，制备出大孔、高比表面纳米级ＴｉＯ２超细粉。详细考察了初始水凝胶ｐＨ值对ＴｉＯ２超细粉形貌、晶相、颗粒大小、比表面积及孔结构等的影响。实验结果发现：当在酸性环境中，所制得的ＴｉＯ２超细粉的比表面积随着ｐＨ值的减小而增大；而在碱性环境中，则随着ｐＨ值的增大而增大。ＴｉＯ２超细粉的比表面积和孔体积由ｐＨ为６．５时的ＳＢＥＴ＝１４２．２ｍ２·ｇ１，ＶＰＮ＝０．４５ｃｍ３·ｇ１，增大到ｐＨ值为１３．０时的ＳＢＥＴ＝４２５．６ｍ２·ｇ１，ＶＰＮ＝１．７９ｃｍ３·ｇ１，且颗粒分布均匀狭窄，颗粒间的三维网络织构更为规整清晰。     

Oxidation of Styrene with Molecular Oxygen in Supercritical CO2

The oxidation of styrene with molecular oxygen catalyzed by PdCl2 CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and seven components during the reaction. The critical temperature, critical pressure, and critical density at different conversions are determined by using a high-pressure view cell. The effect of phase behavior on the conversion and selectivity were studied. Experimental results showed that the critical parameters of the reaction mixture at fixed initial molar ratio changed with the conversion of reactant. The conversion of styrene reached maximum near the critical density of the reaction mixture. Product selectivity also varied with density of reaction mixture and could be tuned to some degree.