壳聚糖的研究进展及其在食品医药工业中的应用

甲壳素是一种丰富的自然资源,壳聚糖是甲壳素脱乙酰化的产物。本文在简单介绍壳聚糖性质及提取方法的基础上,着重论述了壳聚糖在食品、医药工业中的应用情况。随着对壳聚糖及其衍生物研究的不断深入,这种再生资源的利用价值将越来越大。     

甲壳素衍生物的制备工艺

介绍了多种甲壳素衍生物的制备工艺和生产方法 ,包括壳聚糖、羧甲基甲壳素、羧甲基壳聚糖、乙酰化壳聚糖、羧丙 (乙 )基壳聚糖、微晶甲壳素及壳聚糖、盐酸氨基葡萄糖、甲壳素硫酸盐、溴化甲壳素、N-乙基壳聚糖、季铵化壳聚糖、壳聚糖接枝共聚产物等十多种。     

甲壳素衍生物的制备工艺

介绍了多种甲壳素衍生物的制备工艺和生产方法,包括壳聚糖、羧甲基甲壳素、羧甲基壳聚糖、乙酰化壳聚糖、羧丙（乙）基壳聚糖、微晶甲壳素及壳聚塘、盐酸氨基葡萄糖、甲壳素硫酸盐、溴化甲壳素、N-乙基壳聚糖、季铵化壳聚糖、壳聚糖接枝共聚产物等十多种。     

蝉壳壳聚糖的制备和分析

从蝉壳中提取了甲壳素和壳聚糖，脱乙酰度可达９４％，研究了蝉壳甲壳素的脱色条件和高分子量壳聚糖降解为低分子量壳聚糖的方法。     

改性甲壳素和壳聚糖在食品中的应用

本文介绍了甲壳素和壳聚糖及其有关化学改性方法,阐述了水溶性甲壳素和壳聚糖衍生物的制备方法及其在食品工业中作食品添加剂的应用。     

去除甲壳素/壳聚糖中蛋白质的研究进展

介绍了天然多糖甲壳素及壳聚糖中杂质蛋白质对其二者在医用材料界应用的影响,并分别分析论述了国内外已有的去除甲壳素、壳聚糖中蛋白质的方法。去除甲壳素中蛋白质的方法有碱法、酶法、微生物发酵法;去除壳聚糖中蛋白质的方法有碱法、表面活性剂法、色谱法。最后讨论了甲壳素/壳聚糖中蛋白质的去除的研究中存在的问题。     

甲壳素壳聚糖及其衍生物吸湿保湿性研究进展

简要介绍了甲壳素,壳聚糖的物化性质,概述了壳聚糖常见的化学修饰方法,详细综述了甲壳素,壳聚糖及其羟基化化衍生物,羧化衍生物,酰化衍生物的吸湿性和保湿性的研究现状,对β-壳聚糖,甲壳低聚糖的吸湿性和保湿性也进行了介绍。     

甲壳素和壳聚糖纤维的制造与应用

该文介绍了甲壳素和壳聚糖的提取与特性，纺制纤维的工艺和该纤维在医疗方面的应用。     

甲壳素、壳聚糖及其衍生物在生物医药领域中的应用研究近况

随着甲壳素、壳聚糖及其衍生物研究的迅速发展,其研究内容和应用范围越来越广泛。本文主要介绍了它的发展,性质,提取及加工方法以及其在生物医药领域方面的应用和发展研究近况。     

壳聚糖纤维的开发与应用

介绍了甲壳素纤维的制备方法，阐述了甲壳素和壳聚糖纤维的发展历史、开发及应用近况。     

具有硬壳层泡沫玻璃的研究

研究了在泡沫层表面生成一层硬壳层的泡沫玻璃,硬壳层的合适厚度范围是1.5～15mm,其比重为0.8～1.5,泡沫层的比重为0.2～0.6.这种泡沫玻璃改进了无硬壳层泡沫玻璃的机械性能,具有良好的抗冲击性能、抗折性能和机加工性能.该泡沫玻璃可应用在建筑物上作为内外墙装饰材料和保温绝热材料.     

Visualization of crust formation during hot-air-drying via micro-CT

Abstract

Nowadays, hot-air-drying (HAD) is the most common process for the production of dried fruits and vegetables till now. It is well known that HAD has a big influence on product structure leading to effects like shrinkage or case-hardening. While shrinkage has already been documented throughout the drying process, case-hardening or the formation of a crust has only been shown for the dried product. In this study, a three-step approach consisting of a HAD-, a freezing-, and a freeze-drying step is used to show the development of a crust of carrot discs throughout a HAD process. With this method, the crust structures created during HAD were preserved and could be analyzed in a dry state with cone-beam micro-CT measurements. Crust thickness increased significantly during HAD and crust formation started before a relative moisture content of X/X₀ = 0.5.     

挥发性组分引起的预分解窑系统结皮的分析研究

分析了一个水泥厂C5下料管结皮和另一个水泥厂窑尾烟室结皮的化学成分和矿物组成。C5下料管结皮的特征矿物是KCl和2C2S.CaCO3,通过扫描电镜观察了C5下料管结皮内层、中层和外层的微观形貌,并利用能谱仪进行了选区成分分析。另一个水泥厂窑尾烟室结皮是由硫引起的,结皮矿物为CaSO4、2CaSO4.K2SO4、C4A3S,没有发现2C2S.Ca-SO4的存在。深入研究了两种典型结皮产生的原因以及可能的缓解措施。     

Water loss and crust formation during bread baking,Part I: Interpretation aided by mathematical models with highlights on the role of local porosity

This study aimed to achieve greater understanding of the contributions of different mechanisms of water transport to the overall amount of water lost by bread loaves during baking. The analysis was based on simulations from a previously published baking model which takes into account heat and mass transport as well as the expansion of the gaseous phase leading to oven rise. Liquid and gaseous diffusion, convective transport through the gaseous phase (Darcy’s law), and the diffusive transport of vapor (evaporation–condensation–diffusion) were considered. When only permeation (Darcy’s law) prevailed, the greater the porosity of the top dough surface, the lower and slower the water loss (WL): in fact, the greater the porosity, the thicker the top area. This in turn limited the rate at which heat penetrated the top layers down to the vaporization front and slowed WL. At earlier baking times, when the ebullition temperature was not reached uniformly through the crumb, the evaporation–condensation–diffusion was involved at the same time as permeation. The water flux by evaporation–condensation–diffusion was orientated toward the dough core; it accelerated the crust thickening and slowed WL. It appeared that the higher the porosity in the crumb beneath the crust, the higher the flux by evaporation–condensation–diffusion, and the lower the WL. Local porosity variations in the crust (top surface) and the crumb beneath the crust could be reproduced experimentally by constraining the total expansion of the loaf with a permeable fabric cover. Experimental and simulated trends in WL were consistent, supporting the understanding of WL proposed.     

保护渣对连铸板坯裂纹产生的影响

为了了解保护渣对连铸板坯裂纹产生的影响,在生产实践中研究了结晶器中渣层的厚度、弯液面上渣壳的形成情况以及润滑膜的组织结构,结果得知碱度、牯度、结晶温度正确组合可以防止裂纹发生。     

预分解窑结皮与窑皮的X射线衍射分析

通过XRD分析可知：窑尾上升烟道2号结皮JPS2含有相当数量的CaSO4,CaSO4颗粒是导致这个区域结皮的主要物质;上升烟道6号结皮JPS6中的硫酸盐存在形式由熔点较高的CaSO4向熔点较低的R2SO4过渡;引起窑列C5结皮JPA5的活跃组分由硫变成了氯,碱的主要存在形式也由硫酸盐形式转为氯盐形式;形成炉列C2结皮JPB2的黏结力主要体现为表面力,即范德华力、静电力及高的比表面能等。     

汽车后视镜盖注射模具设计

运用Pro/E软件合理设计了汽车后视镜盖注射模具。根据产品的结构,巧妙地利用滑块参与分型,采用对称和边界混合法建立了两塑件间的主分型面和侧抽芯分型面,然后合并成总分型面。为了塑件的顺利脱模,设计了与产品外表面相匹配的非对称斜导柱滑块侧向抽芯机构,避免了由曲面凹凸不平引起的不能正常开模。为提高冷却效果和塑件品质,降低加工成本,缩短生产周期,设计了双向直通式冷却水道,形成了类似回转式冷却系统。     

高效甜味剂三氯蔗糖的应用与合成

介绍了高效甜味剂三氯蔗糖的合成工艺与应用,对各种工艺进行综合评价并提出较好的生产工艺,着重介绍三氯蔗糖的开发前景。     

不导电真空溅镀工艺与手机外壳表面处理

手机的外观装饰要求高,不导电真空溅镀工艺应用于其外壳的表面处理是项新工艺,具有很好的效果.通过分析不导电真空溅镀工艺的原理和特点,介绍了实际应用的生产工艺流程和要点.     

Water loss and crust formation during bread baking,Part II: Technological insights from a sensitivity analysis of a numerical model of baking

A 1D baking model was previously developed to improve the understanding of transport phenomena and bubble formation inside dough. Using this model, the present study focused on crust setting and its particular behavior. Simulation was used to study the influence of various parameters that govern crust setting and its characteristics such as thickness and porosity. On the basis of a literature review, the crust was defined as the “dry zone,” a region where the water content represents less than 0.60?kg/kg of dry matter. The mechanisms responsible for total water loss and crust setting were proposed in paper I and validated for multiple operating conditions: water loss is essentially driven by heat transport and to a lesser extent by the mechanism of water transport by evaporation–condensation–diffusion. In the present study, a sensitivity analysis of parameters of different driving mechanisms was undertaken through which it was possible to establish a hierarchy of the key parameters from a technological point of view. Overall heat transfer coefficient at the top of the loaf and thermal conductivity, or more generally the ratio between top and bottom heat fluxes, were ranked as the main parameters affecting crust setting and the water loss, thus suggesting a possible control of the process through the parameters evaluated.