三种甲醛捕获剂在醛鞣革中的应用效果

对甲醛鞣山羊皮服装革中游离甲醛进行捕获研究,详细对比了胶原蛋白甲醛捕获剂、超支化聚合物甲醛捕获剂及前两者按照不同比例复配的甲醛捕获剂去除游离甲醛的能力.通过单因素实验,优化了甲醛捕获剂的应用工艺参数.结果表明:胶原蛋白甲醛捕获剂用量为1%,捕获时间为4h时,游离甲醛去除率为75.8%;超支化聚合物甲醛捕获剂用量3%,捕获时间4h时,游离甲醛去除率为94.8%;最佳复配质量比例(胶原蛋白甲醛捕获剂:超支化聚合物甲醛捕获剂)为1∶1,用量为3%,捕获时间4h时,复配后甲醛捕获剂游离甲醛去除率为91.0%.     

文昌13-1/2油田液化石油气铜腐超标治理方法的研究及应用

文昌13-1/2油田液化石油气(LPG)回收项目是中海石油(中国)有限公司湛江分公司首个海上LPG回收项目。近年来文昌油田LPG产品时而会发生铜腐测试不合格情况,本文通过对LPG系统硫化氢检测,LPG气样总硫含量测试以及铜片腐蚀产物的能谱测试,发现文昌油田LPG气样铜腐超标和硫含量超标有关。根据海上油田生产环境特点,拟采取湿法脱硫技术,直接加注脱硫剂的方法治理铜腐不合格问题。现场试验加药点选在进口压缩机进口,这样既可以给脱硫剂与硫化氢反应提供空间和时间,又可以在LPG系统较前端将硫化氢治理到较低水平,防止了硫化氢在LPG系统中的扩散。液化气脱硫剂以加注量50mL/min,在现场实践应用的一个月的时间里,可以有效地将铜腐指标从2a降低到1a,确保LPG产品符合国标标准要求。     

Visible light response photocatalytic water splitting over CdS-pillared zirconium–titanium phosphate (ZTP)

With an attempt to extend the light absorption towards the visible range and inhibit the rapid recombination of excited electrons/holes, a new type photocatalysts, cadmium sulfide intercalated zirconium–titanium phosphate (CdS–ZTP) was synthesized. The photocatalysts were characterized by small angle X-ray diffraction studies (SAXS), N₂ adsorption–desorption studies, diffused reflectance UV–vis (DRUV–vis) spectroscopic analysis, photoluminescence studies (PL), scanning electron microscopic/energy dispersive spectroscopic (SEM/EDS), X-ray photoelectron spectroscopic (XPS) studies etc. The samples exhibit a unique property of optical absorption in UV and visible regions with a wavelength, λ ≤ 450 nm followed by a clear long tail up to 700 nm. The pillared materials showed excellent activity for UV–visible light driven hydrogen production from photocatalytic splitting of water without using any co-catalyst. The photocatalytic activity of this cadmium sulfide pillared catalyst, as well as that of neat cadmium sulfide powder, was monitored for the visible light-induced evolution of hydrogen from water in the presence of hole scavenger, sulfide (S²⁻).     

Colour changes and consumer acceptability of bulk packaged pork retail cuts stored under O(2), CO(2) and N(2)

A centralised bulk packaging technique, utilising various gas mixtures, c. 100% CO₂ + oxygen scavenger, c. 80% O₂:20% CO₂ and c. 25% CO₂:50% N₂:25% O₂, was evaluated in terms of consumer acceptability and colour. The inclusion of an oxygen scavenger ensured that pork retail chops bulk packaged in a 100% CO₂ were as acceptable after 0, and 14 days bulk storage and subsequent retail display than chops stored in oxygen-enriched atmospheres. The study also indicated that a saturation level of 10 and higher indicated that the appearance of the pork chop was acceptable to the consumer panel. From the results of this study it is apparent that consumers find pork retail packs, bulk packaged in oxygen depleted atmospheres, as acceptable as pork chops stored in oxygen enriched atmospheres.     

Active warm-water fish gelatin film containing oxygen scavenging system

An oxygen scavenging system (OSS), composed of oxygen scavenging nanoparticles and iron chloride (II), was incorporated into warm-water fish gelatin film. Surface morphology, cross sectional images, and mechanical, barrier, and optical properties of the oxygen scavenging fish gelatin (OSFG) film were compared to those of the unmodified fish gelatin (UMFG) film. Results indicated that the OSS was well incorporated into the OSFG film structure. The OSFG film had rough film surface, increased water vapor and oxygen permeability, and decreased tensile strength due to the incorporation and agglomerations of the OSS. The incorporation of the OSS also caused color and haze alterations to the OSFG film. In addition, the oxygen scavenging capability of the OSFG film was investigated. The initial oxygen content (%) in the cup headspace, 20.90%, was decreased to 4.56% after 50 days of storage. The OSFG film had good oxygen scavenging capacity, 1969.08 cc O₂/m²/mil, and moisture was used as the activator to trigger the oxygen scavenging reaction.     

Analysis of the mechanism of sludge ozonation by a combination of biological and chemical approaches

Using the practical sludge obtained from municipal sewage treatment plants, the mechanism of the sludge ozonation process was systematically investigated by a combination of biological and chemical approaches, including analysis of the changes in biological response by CFU and PCR-DGGE, bio-macromolecular activity and radical scavenging activity. The results indicated that after the sludge was exposed to ozone at less than 0.02 g O₃/g TSS, the DGGE fingerprint remained constant and there was still some enzyme activity, indicating that the sludge solubilization was the main process. At greater than 0.02 g O₃/g TSS, the bacteria began to be broken down and ozone was used to oxidize the bio-macromolecules such as proteins and DNA released from the sludge. Bacteria belonging to ‘G-Bacteria’ were able to conserve their DNA in the presence of less than 0.08 g O₃/g TSS. At levels higher than 0.10 g O₃/g TSS, the disintegration of the sludge matrix became slow and the microbes lost most of their activity, and ozone was used to transform the bio-macromolecules into small molecules. However, at levels higher than 0.14 g O₃/g TSS, the ozone failed to oxidize the sludge efficiently, because several radical scavengers such as lactic acid and SO₄²⁻ were released from the microbial cells in the sludge.     

Mass spectrometry combined with oxidative labeling for exploring protein structure and folding

This review discusses various mass spectrometry (MS)‐based approaches for exploring structural aspects of proteins in solution. Electrospray ionization (ESI)–MS, in particular, has found fascinating applications in this area. For example, when used in conjunction with solution‐phase hydrogen/deuterium exchange (HDX), ESI–MS is a highly sensitive tool for probing conformational dynamics. The main focus of this article is a technique that is complementary to HDX, that is, the covalent labeling of proteins by hydroxyl radicals. The reactivity of individual amino acid side chains with ^. OH is strongly affected by their degree of solvent exposure. Thus, analysis of the oxidative labeling pattern by peptide mapping and tandem mass spectrometry provides detailed structural information. A convenient method for ^. OH production is the photolysis of H₂O₂ by a pulsed UV laser, resulting in oxidative labeling on the microsecond time scale. Selected examples demonstrate the use of this technique for structural studies on membrane proteins, and the combination with rapid mixing devices for characterizing the properties of short‐lived protein (un)folding intermediates. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 29:651–667, 2010     

氧化铁/活性炭负载型硫化氢脱除剂制备及性能评价

为提高硫化氢脱除剂性能,利用活性炭吸附表面积大的特点,合成具有吸附性能的氧化铁负载型硫化氢脱除剂。为便于不同硫化氢脱除剂性能评价,设计和搭建了一种用于快速评价气体硫化氢脱除剂脱除效果的评价方法与实验装置。结果表明,吸附型脱硫剂加入反应型脱硫组分后,脱硫速率的持续性优于吸附型脱硫组分,氧化铁负载质量分数为5%时,脱除剂初始脱硫速率较高。     

Effect of Bio‐Scavengers on the Curing Behavior and Bonding Properties of Melamine‐Formaldehyde Resins

Summary: The effects of bio‐scavengers on the formaldehyde emission, bonding strength, curing behavior, and thermal decomposition properties of MF resins for engineered flooring and adhesion for wood were investigated. Four varieties of bio‐scavengers, tannin powder, wheat flour, rice husk flour, and charcoal, were added to MF resin at 5 wt.‐%. To determine formaldehyde emission and bonding strength, we manufactured engineered floorings. MF‐charcoal was most effective in reducing formaldehyde emission because of its porous nature, but its bonding strength was decreased. Tannin powder and wheat flour, which contain more hydroxyl groups, showed higher bonding strength and curing degree than pure MF resin did. Although the hydroxyl groups of the bio‐scavengers were effective in reducing formaldehyde emission and improve bonding strength and curing degree, rice husk flour and charcoal behaved like inorganic substances, thereby disturbing the adhesion between MF resin and wood and thus reducing the bonding strength. In thermogravimetric analysis, MF‐tannin showed the highest thermal stability in the low‐temperature range from 100 to 300 °C.

Storage modulus (E′) of MF resin with various bio‐scavengers at a heating rate of 10 °C · min^?1.