The Bleaching of Soybean Fabric by Different Treatments Combined with Ozonation

This article is about bleaching of soybean fibers. Although the studies related to dyeing of soybean fibers have been found in the literature, little has been reported on the effect of bleaching. The natural color of soybean protein fibers is pale yellow or cream, and it is therefore usually necessary to bleach them to improve their whiteness. Different bleaching treatments combined with ozonation were performed in order to establish the effect on whiteness, yellowness, lightness, wettability, hydrophility, moisture sorption, and fiber damage properties of knitted soybean fabric. As a result of study, bleaching process combined with ozonation (ozonation + oxidative bleaching + reductive bleaching) supplied soybean fabric with a white appearance (highest whiteness degree), highest hydrophility, and minimal fiber damage.     

葛根膳食纤维漂白工艺的研究

以H2 O2 为漂白剂,探讨了H2 O2 用量、反应时间、反应温度和pH对三种葛根膳食纤维(DF)漂白效果的影响,并用正交试验确定了葛根膳食纤维漂白的最佳工艺条件。结果显示:两种家葛膳食纤维漂白影响具有相同的主次关系,即pH >H2 O2 用量>漂白时间>温度,最佳工艺为:H2 O2 3%,pH 1 0 ,温度70℃,时间6 0min。而野葛膳食纤维影响因素的主次关系为:H2 O2 用量>pH >温度>漂白时间,最佳工艺为:H2 O2 3%,pH 1 1 ,温度80℃,时间6 0min。     

新型荧光增白剂4,4‘—双（2—苯乙烯磺酸基）—联苯的研制

合成了新型荧光增白剂４，４’－双（２－苯乙烯磺酸基）－联苯，测定了其紫外最大吸收波长为３５０ｎｍ，用于棉布的漂白处理，增白效果好。     

Proton saturation and rheological properties of smectite dispersions

Proton-saturated dispersions of the <2-μm fractions of five smectites were prepared. Potentiometric titration data of freshly saturated and autotransformed samples were analysed by calculating proton affinity distribution curves to distinguish different proton interacting sites. Sites with pK values of 2.8 and 11.3 were assigned to protons exchanged for sodium ions and deprotonisation of silanol groups, respectively. Hydrated aluminum ions in freshly proton-saturated dispersions were characterized by pK6. This group of weakly acidic centers also included oligomeric hydroxoaluminum cations because the amount of these sites increased during autotransformation and was accompanied by a shift to pK5.5. The freshly prepared proton-saturated dispersions showed low pH values (2.6), and the particles interacted by edge(+)/face(−) contacts. This increased the viscosity in comparison to the sodium forms at pH7, and, depending on the smectite, yield values between 10 and 400 mPa were observed. Autotransformation removed all sites with pK2.8, reduced the viscosity, the yield value (mostly <10 mPa), and the flow behaviour approached that of the sodium smectite dispersions at pH7. The cause is enrichment of aluminum and/or oligomeric hydroxoaluminum cations in the solution and Stern layer, which leads to fragmentation of the networks into smaller stacks of more densely packed particles.     

Detection limits of coral reef bleaching by satellite remote sensing: Simulation and data analysis

Monitoring of coral reef bleaching has hitherto been based on regional-scale, in situ data. Larger-scale trends, however, must be determined using satellite-based observations. Using both a radiative transfer simulation and an analysis of multitemporal Landsat TM images, the ability of satellite remote sensing to detect and monitor coral reef bleaching is examined. The radiative transfer simulation indicates that the blue and green bands of Landsat TM can detect bleaching if at least 23% of the coral surface in a pixel has been bleached, assuming a Landsat TM pixel with a resolution of 30×30 m on shallow (less than 3 m deep) reef flats at Ishigaki Island, Japan. Assuming an area with an initial coral coverage of 100% and in which all corals became completely bleached, the bleaching could be detected at a depth of up to 17 m. The difference in reflectance of shallow sand and corals is compared by examining multitemporal Landsat TM images at Ishigaki Island, after normalizing for variations in atmospheric conditions, incident light, water depth, and the sensor's reaction to the radiance received. After the normalization, a severe bleaching event when 25-55% of coral coverage was bleached was detected, but a slight bleaching event when 15% of coral coverage was bleached was not detected. The simulation and data analysis agreed well with each other, and identified reliable limits for satellite remote sensing for detecting coral reef bleaching. Sensitivity analysis on solar zenith angle, aerosol (visibility) and water quality (Chl a concentration) quantified the effect of these factors on bleaching detection, and thus served as general guidelines for detecting coral reef bleaching. Spatial misregistration resulted in a high degree of uncertainty in the detection of changes at the edges of coral patches mainly because of the low (∼30 m) spatial resolution of Landsat TM, indicating that detection of coral reef bleaching by Landsat TM is limited to extremely severe cases on a large homogeneous coral patch and shallow water depths. Satellite remote sensing of coral reef bleaching should be encouraged, however, because the development and deployment of advanced satellite sensors with high spatial resolution continue to progress.     

聚膦酸酯型氧漂稳定剂的合成和应用（上）

聚膦酸酯型漂稳定剂是国外一种新弄垢氧漂稳定剂，能够耐浓碱，耐高浓双氧水和耐高温。合成简便，原料价廉易得，生产成本较低。是一只碱氧一浴法和冷轧堆前处理工艺的理想氧漂稳定剂。     

PLC在纸浆漂白中的应用

文中介绍了漂白工段的工艺流程、PLC系统结构和硬件配置及软件实现；并详细介绍了漂白中温度的控制算法。     

前处理工程的重要性

本文论述了印染产品的前处理工程的重要性，包括：前处理工程设计的范围和要求；纤维结构、坯布组织规格及其质量对产品档次、质量的影响；投坯量的控制和前处理车间的责任；退浆、练漂、丝光三个工程对产品档次、质量的影响。     

Structure-radical scavenging activity relationship of alkannin/shikonin derivatives

Alkannins and shikonins (A/S) are naturally occurring isohexenylnaphthazarins (IHNs) of great interest in the field of life sciences due to their broad spectrum of biological properties and are used as food colourants in some countries. In the present study for the first time assessment of the radical scavenging activity of A/S and selected derivatives was carried out using the Crocin Bleaching Assay (CBA) and a modified DPPH assay. Exploration of structure-radical scavenging activity relationship (SAR) was approached with a wide range of A/S derivatives. To accomplish this task, a computational approach was also employed for the two enantiomers and other structurally related compounds. The findings indicated that the side chain –OH group at C-1′ has a positive effect to the radical scavenging properties of alkannin/shikonin by assisting hydrogen atom donation from this carbon atom. Thus, alkannin and shikonin were more potent than deoxyshikonin. Esterification of that hydroxyl group was critical for the activity of the respective compounds (acetyl-, isovaleryl- and β,β-dimethylacryl-shikonin). All of the examined IHN derivatives were found experimentally less potent scavengers than naphthazarin.