微生物还原制备高分散度负载型钯催化剂

用地衣形芽孢杆菌 ( Bacillus licheniformis) R0 8菌体还原、制备高分散度负载型钯催化剂。透射电镜观察表明 ,R0 8菌体能够吸附还原 Pd2 +成 Pd0 颗粒。IR谱分析发现 ,细胞壁上的 - COO- 和 - HPO42 - 基团可能与菌体吸附 Pd2 +的过程有关。XPS测定结果表明 ,在载体 γ- Al2 O3上的 Pd2 +离子被 R0 8菌体还原成 Pd0。所形成的 Pd0 γ- Al2 O3催化剂经加热处理后 ,载体 γ- Al2 O3上的 Pd0 颗粒高度分散 ,其平均粒径为 5nm。该催化剂能够高效地催化一氧化碳的氧化反应

Cloning and expression of egI gene from Penicillium decumbens L-06

【目的】克隆斜卧青霉l-06的内切葡聚糖酶Ⅰ基因(EgI),并实现其在大肠杆菌内的高效表达。【方法】利用rT-PCr技术克隆了斜卧青霉l-06的内切葡聚糖酶Ⅰ基因(EgI),并将EgI基因克隆到原核表达载体中,构建了重组质粒PET32A-EgI。【结果】转化至大肠埃希菌rOSETTA(dE3),经IPTg诱导重组蛋白表达,SdS-PAgE检测结果表明:重组表达产物的相对分子质量约为80 kd,与预期相符。重组表达的菌悬液,经破碎离心,取其上清液,进行纤维素酶活性染色,获得了活性条带。dnS法测得内切酶活力为2.56 Iu/Ml。【结论】构建了斜卧青霉l-06内切葡聚糖酶Ⅰ的原核表达系统。[Objective] The research focus on cloning endoglucanase I(egI) gene from Peni-cillium decumbens L-06 and expressing in Escherichia coli with high efficiency.[Methods] egI gene was cloned from Penicillium decumbens L-06 by RT-PCR method.Recombinant plasmid pET32a-egI was constructed and was transformed into Escherichia coli rosetta(DE3).Recombinant protein with His-tag was expressed in E.coli rosetta(DE3) after induction with IPTG and then was purified with the Ni-NTA affinity chromatography.[Results] As expected,the relative molecular mass was approximately 80kD after analyzed by SDS-PAGE and Western blotting.Hydrolysis activity of recombinant protein was assayed by cellulase activity staining and DNS method(2.56 IU/mL).[Conclusion] The results achieve the purpose as con-structing prokaryotic expression system and expressing egI gene.国家自然科学基金项目(No.41076106);广东省自然科学基金项目(No.S2011030005257);广东省科技计划项目(No.2009B090300346);广东高校科技创新重点项目(No.CXZD1124

The elastic properties and energy characteristics of Au nanowires: an atomistic simulation study

This paper have performed molecular static calculations with the quantum corrected Sutten-Chen type many body potential to study size effects on the elastic modulus of Au nanowires with [100], [110] and [111] crystallographic directions, and to explore the preferential growth orientation of Au nanowires. The main focus of this work is the size effects on their surface characteristics. Using the common neighbour analysis, this paper deduces that surface region approximately consists of two layer atoms. Further, it extracts the elastic modulus of surface, and calculate surface energy of nanowire. The results show that for all three directions the Young's modulus of nanowire increases as the diameter increases. Similar trend has been observed for the Young's modulus of surface. However, the atomic average potential energy of nanowire shows an opposite change. Both the potential and surface energy of [110] nanowire are the lowest among all three orientational nanowires, which helps to explain why Au nanowires possess a [110] preferred orientation during the experimental growth proceeds

苯氧异丁酸类化合物的合成及其体外抗糖尿病活性(英文)

目的设计及合成新型苯氧异丁酸类抗糖尿病化合物。方法关键步骤采用亲核取代反应或M itsunobu缩合反应把亲脂性片段和酸性片段连接成一体,共合成了8个新目标物。用核磁共振、红外、质谱进行结构确认。结果体外胰岛素增敏活性测试(3T3-L1脂肪细胞)结果显示,分别将罗格列酮、吡格列酮、目标物A和B加入已经存在胰岛素抵抗脂肪细胞培养液中,用GOD-POD方法分析得到上清液葡萄糖浓度分别为5.942,6.339,6.226和6.512mmol.L-1。结论目标物A在胰岛素抵抗实验(3T3-L1脂肪细胞)中抗糖尿病活性介于市售PPARγ激动剂罗格列酮和吡格列酮之间,而目标物B的活性略低于吡格列酮

高粱子粒淀粉表面色素的树脂分离研究

对纯化高粱淀粉过程中所得到的淀粉共生天然色素进行了树脂分离纯化研究。得到了树脂分离高粱淀粉共生色素的吸附动力学结果,3 种大孔吸附树脂 HPD-600、AB-8、H103 对高粱红的吸附为慢速平衡型。通过对树脂分离所得色素成份的红外光谱、紫外光谱、质谱分析得出,高粱籽粒淀粉共生色素与高粱壳中的高粱红主要成份是同样的物质,鉴定出所分离的主要成份之一为 5,7,4′-三羟基黄酮

Analysis of stability for networked control systems with large (delays)

针对一类具有随机大时延(大于一个采样周期)的网络控制系统,通过对系统的离散化,从理论上分析了系统的稳定性.利用分割的思想处理随机的网络时延,采用离线控制器设计与在线切换规律设计相结合的方法,给出了系统基于控制器切换技术的稳定的梯度算法.仿真算例说明了结论与算法的正确性

Separation of Acetic Acid/Water Mixture by Distillation and Distillation Coupled Pervaporation

[中文摘要]模拟计算考察乙酸/水混合物精馏特性,比较精溜及精馏/膜集成分离过程的能耗特点。塔中部进料,进料级附近出现夹紧点,而塔底部进料时,塔上部出现夹紧点。不同位置的侧线采出通过膜分离后返回塔内对分离效果有影响,且存在一较佳的侧线采出塔级。计算表明通过精馏—膜集成过程制备无水乙酸可能是一种有应用前景的分离技术。［英文摘要］Separation of acetic acid/water mixture by distillation and distillation coupled pervaporation was simulated to compare the difference in the energy consumption between these two technologies. The composition profiles tend to pinch towards the feed when feed at the middle of the tower and tend to pinch towards the top end when feed at the bottom end. It was found that the energy-cost in the coupled process was reduced vs. the distillation. The location of the membrane feeding has impact on the separation and there is a maximum position for fedding to the membrane.It may be concluedd that distillation-coupled pervaporation could be an alternative for water removal from acetic acid /water mixture.福建省自然科学基金(F00022

Input Saturation Control for Switched Linear Systems

利用开关系统切换的特点研究了线性开关系统的饱和控制问题,在较弱的条件下,得到了开关系统饱和镇定的结果,即构成开关系统的每个子系统可以是非稳定的,但假定由开关系统构成的某个凸组合系统是可稳的.借助于Lyapunov函数设计饱和控制器,基于凸组合系统的稳定性设计切换规律,引入设计参数满足控制器实现的条件,使开关系统局部渐近稳定