Oxidation kinetics of anthracene with nitrogen dioxide in acetic acid

Kinetics of liquid-phase oxidation of anthracene to anthraquinone with nitrogen dioxide in acetic acid as solvent has been studied. The reaction takes place through the anthrone as intermediate compound. The first and second reactions are first order with respect to anthracene and anthrone concentration, respectively. The values of the rate constants in the temperature range 60–95°C have been reported. According to the reaction system developed, an industrial process for the manufacture of anthraquinone of high purity has been proposed.     

低成本焦化厂混凝出水氧化脱色工艺的研究

针对焦化废水经萃取脱酚-生化处理-化学混凝三级处理后的出水水质，提出了化学氧化脱色工艺。研究了有机氯氧化剂浓度、pH值、温度、时间等因素对脱色的影响。确定工艺流程为混凝出水不调pH、不加热，直接投加-定量的有机氯氧化剂，反应进行3h后，过滤。采用GC-MS方法分析了水样中的有机物成分．结果表明焦化废水经三级处理后仍然含有各种生色团和助色团的有机化合物如3-甲基-1，3，6-庚三烯、5-降冰片烯-2-羧酸、2-羟基-苯并呋喃、苯酚、2-氯-2-降冰片烯、1-甲磺酰基-4-甲基苯、3-甲基苯并噻吩、萘-1．8-二胺等。是形成高色度水质的主要原因。     

催化裂化柴油空气氧化脱硫工艺研究

实验以空气作氧化剂,甲酸作催化剂,甲醇作萃取剂,以催化氧化反应与溶剂萃取相结合法,对催化裂化柴油进行氧化萃取脱硫。经单因素实验考察了催化剂用量、催化氧化温度、时间、空气压力及萃取剂的用量等对催化裂化柴油硫含量的影响。适宜的脱硫条件为:反应温度80℃,反应时间60 min,空气压力0.6 MPa,催化剂用量10%(与柴油的体积比)。经催化氧化,柴油硫含量可由1 694.2μg/g降至347.3μg/g,脱硫率达79.5%。     

Protection of deoxyribose and DNA from degradation by using aqueous extracts of several wild plants

BACKGROUND: Aqueous extracts of 48 herbal plants were obtained via alternative extraction protocols, and were assayed for their capacity to protect deoxyribose and DNA itself from degradation (or, conversely, for their capacity to promote DNA degradation), using electrophoresis as analytical tool. RESULTS: For a given (constant) volume of extract, deoxyribose protection ranged from 14.13 ± 1.35% (mean ± SD) inhibition by dwarf mallow powder infusion, up to 106.51 ± 15.93% inhibition by avocado powder infusion. DNA protection was tested at two extract concentrations, and was slightly greater at the higher concentration. Pro‐oxidant effects were essentially absent. CONCLUSION: The anti‐oxidative roles of plants upon deoxyribose and DNA displayed by our experimental results were rather promising with regards to practical applications of those plants, viz. as ingredients in the formulation of nutraceutical beverages and/or foods. Copyright © 2007 Society of Chemical Industry     

The effects of bimetallic interactions for CO2-assisted oxidative dehydrogenation and dry reforming of propane

The catalytic reduction of CO₂ by propane may occur via dry reforming to produce syngas (CO + H₂) or oxidative dehydrogenation to yield propylene. Utilizing propane and CO₂ as coreactants presents several advantages over conventional methane dry reforming or direct propane dehydrogenation, including lower operating temperatures and less coke formation. Thus, it is of great interest to identify catalytic systems that can either effectively break the C C bond to generate syngas or selectively break C H bonds to produce propylene. In this study, several precious and nonprecious bimetallic catalysts supported on reducible CeO₂ were investigated using flow reactor studies at 823 K to identify selective catalysts for CO₂-assisted reforming and dehydrogenation of propane.     

卷烟纸中助燃剂含量的控制

分析卷烟纸中助燃剂含量的影响因素,控制助燃剂含量,稳定卷烟纸的燃烧速度,从而控制卷烟后烟支的焦油含量。     

氧化裂化合成生物质碳材料及其电化学性能研究

生物质碳材料具有成本低、来源广泛、孔隙率可调可控、形貌多样、易生产、易掺入杂原子等优点,因此,生物质碳基材料的开发和应用成为现代材料科学一个非常重要的领域。将植物叶片用不同氧化剂进行水热氧化处理,600℃碳化得到生物质碳材料。水热氧化处理工艺与传统热裂解工艺相比,降低了裂解温度,极大程度保持了叶片脉络结构,得到类石墨烯的薄层碳化材料。样品通过XRD、XPS、TEM、SEM等进行表征。结果表明,用不同氧化剂水热氧化所得到的碳材料元素组成和微观结构差别较大。当氧化剂为高锰酸钾时,所得到的生物质碳材料(MnOC)既保留了叶片原有的微观孔道,又形成了新的孔隙,比表面积可达482.934 m^2/g,平均孔径为3.833 nm。从XPS、XRD分析可以看出,MnOC样品石墨化程度相对较高,并最大程度保留了N元素(原子百分比为6.5%)。TEM、AFM图像分析表明,MnOC样品呈片层结构,厚度不足2 nm,将其制备成电极片,在电流密度为1 A/g时,比电容可达191.15 F/g。     

单晶SiC电化学腐蚀及化学机械抛光

通过电化学工作站对4英寸(1英寸=2.54 cm)n型单晶SiC(4H-SiC)进行电化学腐蚀特性研究,采用36GPAW-TD单面抛光机对其Si面和C面进行了化学机械抛光(CMP)。结果表明,采用H2O2和NaClO作为氧化剂,均可促进SiC的电化学腐蚀并提高其抛光去除速率,其促进作用与氧化剂浓度和抛光液的pH值密切相关。选择含体积分数5%的H2O2、pH值为12的SiO2抛光液对SiC进行CMP,得到的Si面抛光速率可以达到285.7 nm/h。在含H2O2抛光液中引入适量的NaNO3和十二烷基硫酸钠,SiC表现出较高的腐蚀电位绝对值和去除速率。在H2O2和NaClO抛光液体系中,SiC的去除速率与其腐蚀电位的绝对值正相关,该结果对实际应用有一定的借鉴意义。     

氧氮丙啶在有机合成中的应用

介绍了氧氮丙啶的制备方法及其作为胺化剂和氧化剂在消除、分解、重排等反应中的应用。     

污水厂高浓度氯离子出水中COD测定方法的研究

针对污水处理厂出水COD测量中的氯离子干扰问题,从测定原理、消除效果及适用范围等方面对常用的几种标准方法进行了比较,并对筛选出的适用方法进行了实践.结果表明,低浓度氧化剂法、氯气校正法的结果相近,是测定污水厂高浓度氯离子出水中COD的可行方法.