Effect of high power ultrasonic treatment on whey protein foaming quality

High power ultrasonic energy at 20%, 40% and 60% amplitude was applied on whey protein suspension at concentrations of 100, 150 and 200 g kg^?1 for 5, 15 and 25 min to improve its foaming quality. Ultrasound‐treated whey protein suspension at 200 g kg^?1 showed improvement in terms of increased foaming capacity by 18%, foam stability by 35%, consistency index by 18%, storage modulus by 17%, loss modulus by 26% and viscosity by 21% compared with untreated whey protein. For maximally ultrasound‐treated samples of 60% amplitude treated for 25 min, the improved whey protein foams also had a 46% increase in the number of more evenly distributed fine bubbles which had a size smaller than 0.0025 mm³ as imaged using X‐ray microtomography.     

Effects of pretreatment and drying methods on molecular structure,functional properties and thermal stability of fibre powder exhibiting colour from Centella asiatica L.

Effects of pretreatment and drying methods and particle size on characteristics of fibre powder from Centella asiatica L. leaves were investigated. Thermal stability of oil‐based colour solutions was also assessed. Steaming and combined steaming and alkaline soaking resulted in the powder with more greenness and higher chlorophylls contents, while combined steaming and acid soaking yielded dark yellow powder with lower chlorophylls contents. Chemical soaking led to the powder with decreased water holding capacity and solubility. Vacuum‐drying reduced chlorophylls degradation, hence retention of the greenness of the powder. Increased particle size resulted in decreased lightness of the powder, but in increased lightness of the solutions; water and oil holding capacities of the powder increased with the particle size. Fourier transform infrared (FTIR) spectra and X‐ray diffraction (XRD) patterns of the powder corresponded to its colour and functional property changes. Colour of the solutions changed only slightly upon heating at 80 and 180 °C for 1 h.     

X80级抗大变形管线钢焊接粗晶区的组织和性能

采用热模拟技术研究了X80级抗大变形管线钢焊接粗晶区组织、显微硬度和韧性的变化规律,分析了焊后冷却速度和粗晶区组织、性能之间的关系.结果表明,X80级抗大变形管线钢焊接粗晶区组织类型主要为铁素体和少量珠光体、粒状贝氏体、板条贝氏体和板条马氏体4种类型.焊接粗晶区软化是X80级抗大变形管线钢焊接面临的主要问题.当焊后冷却速度在15～30℃/s之间时,X80级抗大变形管线钢焊接粗晶区的强度、室温以及低温韧性匹配良好,组织以板条贝氏体为主.     

X80管线钢埋弧焊匹配焊丝试验

通过分析高强度低合金钢焊缝熔敷金属常见显微组织对其力学性能的影响,确定X80管线钢用埋弧焊丝熔敷金属组织应以大量针状铁素体(AF)和少量粒状贝氏体(GB)的复合组织.从相变动力学原理出发,结合针状铁素体(AF)非自发形核机制和微合金组织韧化理论,选择Mn-Ni-Mo-Ti-B合金系进行X80管线钢匹配焊丝的试制.结果表明,合理选择和控制合金元素,可以获得理想的焊缝熔敷金属组织和强韧性以及低温韧性要求,试制的1号焊丝能够满足X80管线钢的使用要求.     

脉冲激光沉积法生长Zn1-xMgxO薄膜

采用脉冲激光沉积法,生长出没有组分偏析,晶体质量好的Zn1-xMgxO薄膜(x=0.2).研究了衬底温度对Zn0.8Mg0.2O薄膜晶体质量、晶粒度大小的影响,发现最佳衬底温度为650℃左右.对Zn0.8Mg0.2O薄膜进行了光致发光分析,发现相对ZnO晶体有0.4eV的蓝移.     

冷却速度对X12CrMoWVNbN10-1-1耐热钢的力学性能影响

采用力学性能测试、金相分析以及TEM微观结构分析,研究了淬火和回火冷却速度对X12CrMoWVNbN10-1-1耐热钢力学性能的影响,并探讨了脆化机制,结果表明:在相同的回火工艺下,随淬火冷却速度的降低,强度降低,塑性变化不大,但冲击值增加,其主要原因是缓冷降低了马氏体基体的再结晶温度,导致基体的回复与再结晶程度增加;...     

基于X3D的三维用户界面组态引擎设计

传统组态软件二维用户界面仿真度低,不能直观反映工业现场生产情况,针对该问题设计并实现了基于X3D的组态软件三维用户界面组态引擎.介绍了三维用户界面组态引擎的系统架构以及使用该引擎进行场景组态时的流程;基于X3D建立了三维场景对象库,并建立对象之间的关联作为场景组态的约束关系,利用其加快场景组态过程;使用XJ3D图形工具包实现了该引擎的原型系统.实验证明该引擎组态简便,使用其组态生成的三维用户界面具有较好的仿真效果.     

基于X3D的分布式虚拟现实场景三维建模

论文分析了基于Web的分布式虚拟现实场景建模的几种常用方法,在对比其优缺点的基础上提出了采用一种基于XML的全新三维图形规范来构建虚拟现实的场景,并给出了应用实例。     

Rubber–clay nanocomposite by solution blending

Ethylene vinyl acetate rubber (45% vinyl acetate content, EVA‐45) and organomodified clay (12Me‐MMT) composites were prepared by solution blending of the rubber and the clay. A combination of X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy studies showed that the composites obtained are on the nanometer scale. The measurements of the dynamic mechanical properties for different compositions over a temperature range (?100 to +100°C) showed that the storage moduli of these rubber–clay nanocomposites are higher above the glass to rubber transition temperature compared to the neat rubber. The tensile strength of the nanocomposites is about 1.6 times higher than that of the EVA‐45. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2216–2220, 2003     

Co-LsX催化苯乙烯生成环氧苯乙烷绿色合成工艺研究

采用离子交换法制备Co-LsX催化剂,分子筛经Co2+离子交换后,其骨架结构没有发生变化。考察了反应温度、反应时间、催化剂用量、溶剂加入量及氧气通入速率等因素对苯乙烯环氧化反应的影响。得出最佳工艺条件:反应温度100℃,反应时间6 h,Co-LsX与苯乙烯质量比为0.16,混合溶剂与苯乙烯体积比为5;V(O2)∶V(苯乙烯)=1.3 min-1。在此条件下苯乙烯转化率达到62.5%,环氧苯乙烷的选择性达到57.1%。催化剂经6次循环使用后活性和稳定性都比较好。