Modification of margarine fats by enzymatic interesterification: Evaluation of a solid-fat-content-based exponential model with two groups of oil blends

Lipozyme TL IM-catalyzed interesterification for the modification of margarine fats was carried out in a batch reactor at 70°C with a lipase dosage of 4%. Solid fat content (SFC) was used to monitor the reaction progress. Lipase-catalyzed interesterification, which led to changes in the SFC, was assumed to be a first-order reversible reaction. Accordingly, the change in SFC vs. reaction time was described by an exponential model. The model contained three parameters, each with a particular physical or chemical meaning: (i) the initial SFC (SFC₀), (ii) the change in SFC (ΔSFC) from the initial to the equilibrium state, and (iii) the reaction rate constant value (k). SFC_o and ΔSFC were related to only the types of blends and the blend ratios. The rate constant k was related to lipase activity on a given oil blend. Evaluation of the model was carried out with two groups of oil blends, i.e., palm stearin/coconut oil in weight ratios of 90∶10, 80∶20, and 70∶30, and soybean oil/fully hydrogenated soybean oil in weight ratios of 80∶20, 65∶35, and 50∶50. Correlation coefficients higher than 0.99 between the experimental and predicted values were observed for SFC at temperatures above 30°C. The model is useful for predicting changes in the SFC during lipase-catalyzed interesterification with a selected group of oil blends. It also can be used to control the process when particular SFC values are targeted.     

仿生特殊浸润性界面在化学工程与工艺中的应用

仿生特殊浸润性界面材料是一类新兴的功能材料。此类界面材料与特定流体之间存在极致的相互作用,如完全浸润、完全不浸润及可调性浸润等,使其在物理学、化学、工程学、生命科学等学科都发挥出特殊的功能。通过学习自然界具有特殊结构与化学组成的生命体,研究人员可以构筑多种对流体具有排斥、吸引、疏导等作用的特殊浸润界面材料,从而优化目前科研及生产中的流体操控过程。“三传一反”中存在大量的固/液/气多相作用过程,这为仿生特殊浸润界面材料提供了重要的应用场所,同时也对此类材料的设计提出了新的要求。介绍了仿生特殊浸润界面材料在传统化工相关领域的几类应用,包括冷凝换热、多相分离体系、设备防腐防污,非均相催化,以及定向流体传质等方向,并总结仿生特殊浸润界面材料在化工过程中应用的挑战与机遇,对此类界面材料在化工过程中的发展前景进行展望。     

气-固流化床压力脉动信号的多尺度排列熵分析

采用多尺度排列熵算法对气-固流化床内4种流型的压力脉动信号进行研究,结果表明:不同流型由于其动力学特性不同,导致压力脉动信号的多尺度排列熵值存在差异——4种流花形态的排列熵值都是随着尺度的增加而增大,其中固定床在大尺度上熵值最大,气力输送床在小尺度上熵值最大,鼓泡流化床在所有尺度上熵值最小;此外,多尺度排列熵值变化速率特征是流型辨识的新指示器。     

Z法气体超声波流量计湿气测量的虚高预测模型

引言湿气通常是指气相为连续相,液相为离散相的气液两相流。美国机械工程师学会ASME将其界定为Lockhart-Martinelli参数(L-M参数)X<0.3的气液两相流[1]。湿气普遍存在于自然界与工业现场中,如常规天然气田井口产出气(湿天然气)、煤层气、湿饱和蒸汽以及页岩气等均属湿气。随着工业生产的发展,对湿气不分离计量的要求越     

电镀制备铟-锡合金电极及其电还原二氧化碳性能

以腐蚀铜网为基体,在硫酸盐镀液中制备得到用于电还原CO2的铟-锡合金电极。对镀液配方进行了筛选,并通过正交试验对镀液配方进行优化,得到制备铟-锡合金电极的最佳工艺条件为:In2(SO4)350g/L,SnSO430g/L,柠檬酸40g/L,添加剂TSNA4g/L,稳定剂3g/L,电流密度1.5A/dm2,温度25°C,pH约1.5。最佳工艺下制备的In-Sn合金镀层呈均匀的灰白色,结合力良好,In-Sn合金电极上电还原CO2生成甲酸的电流效率达71%,稳定性良好。     

双介孔炭制备及应用研究进展

双介孔炭材料具有两种不同的介孔孔径,可以满足不同直径分子的传输需要,并且具有惰性的材料表面,有利于改性,因此日益受到研究者的广泛关注.本文较为详尽地介绍了目前双介孔炭材料的制备方法及应用现状,指出有效控制孔结构、孔径分布及进一步开发双介孔炭材料的应用是未来研究的主要方向.     

Visible light localization algorithm based on multi-measurements constraints

In the indoor visible light transmission environment with complex noise, traditional received signal strength indication(RSSI)localization algorithm and imaging localization algorithm are unable to accurately determine the reason of the inaccurate localization model and inadequate constraints of position coordinates. In order to solve the problems, a visible light localization algorithm based on multi-measurements constraints is presented in the paper. The algorithm first constructs a joint localization state space model based on RSSI localization and the imaging localization algorithm. Then, states, measurements and their equations are constructed based on the space model. Finally, the equations are resolved using the unscented Kalman filter(UKF). Compared with RSSI localization and imaging localization, simulation results show that the RMSE of the proposed algorithm could be closer to the Cramer Rao bound. Besides, the localization probability of the proposed algorithm is higher than that of RSSI localization and imaging localization algorithm.     

纳米TiO2的分散及其复合内墙涂料的研制

采用无机纳米TiO2对水性建筑内墙涂料进行改性,结果表明：当纳米TiO2含量为2．5％时效果最好,使涂层表面平整、光滑、致密,纳米晶粒在涂层表面均匀分布;涂料的贮存稳定性和耐碱性能得到明显的改善,尤其是耐擦洗性提高了近10倍。另外,涂膜干燥时间大大缩短,附着力、耐水性都优于普通水性建筑内墙涂料。     

丁腈-40增韧室温固化环氧结构胶

采用丁腈-40液体橡胶对环氧体系进行增韧,研究了丁腈-40液体橡胶含量、甲组分处理温度及时间对所制备环氧结构胶剪切强度的影响。结果显示:环氧树脂和橡胶的最佳质量比为10∶1;所得结构胶室温固化24h,室温剪切强度最高可达22.4 MPa,具有良好的力学性能。