Enantioseparation of catechin and epicatechin in plant food by chiral capillary electrophoresis

The enantiomers of catechin and epicatechin were separated by chiral capillary electrophoresis using modified cyclodextrins as chiral selectors. Various conditions for the separation system were optimized, including the pH value and the concentration of the running buffer. A baseline separation of the catechin and epicatechin enantiomers could be achieved by using 0.1 mol l⁻¹ borate buffer (pH 8.5) with 12 mmol l⁻¹ (2-hydroxypropyl)-γ-cyclodextrin as chiral selector, a fused-silica capillary with 40 cm effective length (75 μm I.D.), +18 kV applied voltage, a temperature of 20 °C and direct UV detection at 280 nm. The method was applied to different plant food samples. (+)-Catechin and (−)-epicatechin could be verified as the most common flavan-3-ols. In the case of guaraná, however, we were able to identify all four enantiomers, both (+)- and (−)-catechin and (+)- and (−)-epicatechin, as naturally occurring compounds. This finding was verified by further isolation and purification of the flavan-3-ols and subsequent LC–MS analysis. This method allows for the identification of the authenticity of guaraná through the analysis of the catechin and epicatechin enantiomers, additionally to the conventional methods like HPLC.     

Performance Characteristics of a Drying Heat Pump Using Superheated Steam

A complete mathematicalhumerical model is proposed, in order to simulate the performance characteristics of a novel concept of a drying heat pump based on the theory of minimum energy cyclcs. The drying heat pump involvcs vapour condensation in a Lava1 nozzle. removal of the liquid phase in a supersonic separator as well as compression of the working medium. which is superheared vapour.     

Study on phase behavior–impact strength relationship of unsaturated polyester/polyurethane hybrid polymer network

The phase behavior of a hybrid polymer network (HPN) composed of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] crosslinked with styrene and polyester–urethane crosslinked with methylene-bis-ortho-chloroaniline was examined. The correlation between phase separation and impact strength of the HPNs is discussed. The composition of HPNs has an effect on their properties.     

K_2O－B_2O_3－SiO_2玻璃成分对析晶性能的影响

本文利用ＤＴＡ、ＸＲＤ、ＴＥＭ、ＳＥＭ等技术研究了三种Ｋ２Ｏ－Ｂ２Ｏ３－ＳｉＯ２玻璃的析晶性能。结果表明，Ｋ２Ｏ－Ｂ２Ｏ３－ＳｉＯ２玻璃的析晶由分相引起，分相和析晶能力受成分影响较大。随Ｂ２Ｏ３和Ｋ２Ｏ含量增多及Ｋ２Ｏ／Ｂ２Ｏ３比值的降低，析晶加强。析晶中主晶相类别尚未查清，次晶相确定为α－方石英。     

NUMERICAL SIMULATION OF PARTICLE SEPARATION IN AN OIL-SAND SEPARATOR

ＮＯＴＡＴＩＯＮＳＡ　Ａｒｅａｏｆｉｎｌｅｔ ,ｍ2ａ　Ｃｅｎｔｒｉｆｕｇａｌａｃｃｅｌｅｒａｔｉｏｎ ,ｍ2 /ｓｉ　Ｇｒｉｄｏｆａｘｉａｌｄｉｒｅｃｔｉｏｎｍｌ 　ＭａｘｉｍｕｍｇｒｉｄｎｕｍｂｅｒｏｆｒａｄｉａｌｄｉｒｅｃｔｉｏｎＱ　Ｆｌｕｉｄｍａｓｓｒａｔｅ ,ｍ3/ｓＲｃ 　Ｍａｘｉｍｕｍｒａｄｉｕｓｏｆｃｙｃｌｏｎｅ ,ｍＲｅ　Ｒｅｙｎｏｌｄｓｎｕｍｂｅｒｒ　Ｄｉｍｅｎｓｉｏｎｌｅｓｓｒａｄｉａｌｄｉｓｔａｎｃｅｔ　Ｄｉｍｅｎｓｉｏｎｌｅｓｓｔｉｍｅｕ　Ｄｉｍｅｎｓｉｏｎｌｅｓｓａｘｉａｌｖｅｌｏｃ…     

甲醇与碳酸二甲酯共沸液的分离研究进展

综述了DMC-CH_3OH二元共沸液的各种分离方法。讨论了共沸精馏和萃取精馏的工艺流程。     

制氧(全)系统停车的迅速恢复和预防

介绍了安阳钢铁公司制氧厂结合实际总结出的制氧 (全 )系统停车的迅速恢复的操作方案和预防停车的措施 ;分析了经济效益。现机组自启动到送氧只需 2 3个小时 ,比设计值减少约 2 5小时。     

重油催化裂化反应技术的新进展

近十几年来，重油催化裂化技术作为主要的重质油轻质化手段得到了迅速发展，国内外围绕催化裂化装置的提升管反应器也开发了许多新技术。综述了重油催化裂化反应技术的新进展，并对新技术的开发进行了讨论。     

面向染料清洁生产和染料废水处理的纳滤技术

综述了纳滤膜对含盐染料溶液的分离原理、纳滤膜的选择、纳滤脱盐浓缩工艺过程与应用研究、纳滤处理染料废水与资源化方面的应用研究、纳滤技术的经济性以及应用过程中膜污染的控制。指出利用纳滤技术改进染料生产工艺是可行的,能够实现染料清洁生产,具有明显的经济效益和环境效益;采用纳滤处理染料废水,浓缩液和透过液可以分开处理,易于资源化,并且有利于染料废水的后继处理,是高浓度高含盐染料废水的一种有效处理方法。     

从废钼合金催化剂中提取钼等有价元素方法的研究

ＭｏＣｏＮｉ合金料首先氧化焙烧碱浸出，滤饼再加纯碱焙烧水浸出使钼与钴镍分离，最后用萃取法分离钴镍的工艺流程，对废钼合金催化剂进行了综合回收。采用该工艺流程和生产线分别生产出合格的工业级钼酸钠、氧化钴和氧化镍。