Fluorescence study of the solubilization of benzo[a]pyrene: application to its detection in coal washing waters

The solubilization of benzo[a]pyrene by organic solvents (dioxane, toluene and dichloromethane) and a surfactant (Triton X-100) was investigated. These media were successfully used for the determination of benzo[a]pyrene using fluorescence detection, with excellent limits of detection and large linear analytical ranges. Benzo[a]pyrene was detected in coal washing waters using liquid chromatography with fluorescence detection. The stability of this compound in dioxane was also examined.     

Modification of silica gel with diethylamino group by novel reaction and its characterization

1,3,5,7-Tetramethylcyclotetrasiloxane (H₄) was deposited on silica gel at 80°C by utilizing a chemical vapor deposition (CVD) method, where it was catalytically polymerized to form a surface coating of polymethylsiloxane (PMS). Treated silica gel (PMS-Si) increased in weight up to a plateau level, and there was no further increase with increasing reaction time. The film of PMS was partially cross linked; typical values of crosslinking ratio and film thickness were 2% and 0.6 nm, respectively. An anionic ion exchanger containing diethylamino groups was synthesized from PMS-Si by hydrosilylation of allyl glycidyl ether followed by treatment with diethylamine. Its structure was confirmed by¹³C and²⁹Si CP/MAS NMR spectroscopy and FT-IR spectrophotometry. Characterization of silica gel (DEA-Si) modified with diethylamino group was evaluated by a packing of the column for liquid chromatography. As a mixture of five nucleotides was completely separated, it was recognized that DEA-Si was operated by ion exchange action. Because the surface of the silica gel was covered with hydrophobic PMS, the peak heights and retention times did not change after washing of the column with alkaline solution.     

Interaction between indigo and adsorbed protein as a major factor causing backstaining during cellulase treatment of cotton fabrics

A model microassay system was developed to measure indigo backstaining on cotton fabrics in the presence of enzymes on a small laboratory scale. Backstaining indexes for 11 cellulase samples were measured, and the enzymes were ranked from lower to higher backstaining. Two multienzyme cellulase preparations were separated into fractions using chromatofocusing on a Mono P column. Adsorption ability and backstaining properties of purified enzyme fractions were studied. Evidence was obtained that protein adsorption on cotton fabrics is a crucial parameter causing backstaining (both for crude cellulase samples and purified enzyme components).     

Ethanol Washing Effect on Textural Properties of the Sodium Silicate-Derived Silica Xerogel

This study deals with the use of ethanol as washing solvent in the preparation of the silica gels from sodium silicate in order to enhance the textural properties, especially surface area. We here examined the effect of ethanol-washing on surface area, micro- and mesopore volume, and average pore size. The silica xerogels prepared from sodium silicate solution exhibited an extremely high surface area of 1139 m2/g by washing their hydrogels with ethanol. Compared to water-washed xerogels, ethanol-washed xerogels showed higher surface areas, total pore volumes, and larger average pore sizes. Unlike the surface area of water-washed xerogel, that of the ethanol-washed xerogel was not affected by the silica concentration of initial solution. This study indicates that the textural properties of sodium silicate-derived xerogels are further enhanced by using ethanol as washing solvent.     

三晶S350变频器在工业水洗机上的应用

工业水洗机要求变频器能提供高转矩、多段速、宽电压、自动转差补偿和方便的通讯方式;还要求性能稳定,能适应不同的布草水洗车间高温、高湿的环境;还要求通讯获取变频器的输出频率并转换为转速实时地显示出来,对不同的布草可以方便地设定所需的洗涤和脱水速度,并能很好地兼顾高转速和大转矩两个方面。三晶S350矢量变频器采用了V/F曲线自动调节技术,根据洗涤状况自动诊断及调整V/F曲线,能满足工业水洗机的上述工艺要求,我厂2008年首次在100kg型全自动水洗机上应用,运行至今,稳定可靠。     

自动电位滴定法测定冷轧薄板酸洗液中总酸度

自动电位滴定法测定酸液中总酸度具有简单、快捷、不受其他元素干扰等优点。用硫代硫酸钠掩蔽铁离子,利用自动电位滴定仪测定冷轧薄板酸洗液的总酸度(以盐酸量计)。当电位突变达30mV以上时,仪器自动判定滴定终点。自动电位滴定法测定冷轧薄板酸洗液中总酸度结果与酸碱中和滴定方法具有较好的一致性。相对标准偏差小于0.6%,能够满足生产检验的要求。     

Ultrasonic washing of textiles

We present the results of experimental investigation of ultrasonic washing of textiles. The results demonstrate that cavitation bubbles oscillating in acoustic fields are capable of removing soils from textiles. Since the washing performance is mitigated in a large washing bath when using an ultrasonic transducer, we propose a novel washing scheme by combining the ultrasonic vibration with a conventional washing method utilizing kinetic energy of textiles. It is shown that the hybrid washing scheme achieves a markedly enhanced performance up to 15% in comparison with the conventional washing machine. This work can contribute to developing a novel laundry machine with reduced washing time and waste water.     

The removal of Cu,Ni, and Zn in industrial soil by washing with EDTA-organic acids

In order to improve the heavy metal removal ability of traditional single washing agents and explore the removal mechanism of heavy metals. Then, the washing reagents that mixed by low-molecular weight organic acids (citric acid, oxalic acid, and tartaric acid) and artificial chelating compound ethylenediaminetetraacetic acid disodium (EDTA) were selected. Furthermore, the effect of soil washing parameters, the variation of leaching toxicity, mobility, stability and speciation of heavy metals were also considered. The results of soil washing experiments showed that mixing an equal volume of 0.05 M EDTA and 0.2 M organic acids (citric acid, oxalic acid, and tartaric acid) could remove more than about 80% heavy metals from soil under the optimal conditions. In addition, the soil leaching toxicity was decreased and the stability of remaining heavy metals was increased, indicating that EDTA-organic acid washing reagents could effectively reduce the ecological risk of contaminated soil. EDTA had a stronger chelating ability with heavy metals than the organic acids, and the organic acids could not only chelate heavy metals but also decrease the pH of the mixture for promoting the desorption of heavy metals. Thus, mixing EDTA and organic acids was advisable method to improve soil washing technology.     

活性炭前处理对双电层电容器性能的影响

制备了沥青焦基活性炭双电层电容器用电极材料,将其分别经水洗、酸洗以及超音速气流粉碎处理。在1 mol/L(C2H5)4NBF4/碳酸丙烯酯电解液体系中进行电化学测试,对比评价了各活性炭前处理方法对电容器电化学性能的影响。结果表明,酸洗后活性炭电极比电容提高7%达到163 F/g,高功率放电性能明显改善,当电流密度由70 mA/g增加到1 A/g时,其电极比电容保持率为88%;活性炭进行超细粉碎后不利于电化学性能的提高。     

水洗和回烧工艺对高镍三元材料LiNi0.88Co0.07Al0.05O2微观结构及电化学性能的影响

以镍钴氢氧化物、异丙醇铝为原料,采用水解法合成三元前驱体Ni_(0.88)Co_(0.07)Al_(0.05)O_2,再与锂盐混合烧结得到正极材料(TEM)、X射线光电子能谱(XPS)、能量色散X射线谱(EDS)和恒电流充放电测试等对样品的晶体结构、微观形貌、元素价态以及电化学性能进行表征。研究表明,料液比1∶25、水洗3次、600℃回烧2 h合成的LiNi_(0.88)Co_(0.07)Al_(0.05)O_2具有较优的综合电化学性能,其在0.2C的放电比容量达207.6 mAh·g~(-1),首次充放电效率为84.8%,1C放电比容量为192.0 mAh·g~(-1),循环100周后,材料的放电比容量仍有148.0 mAh·g~(-1),容量保持率达到77.1%。