CO2在p—SiC膜电极上的光电化学还原

近年来,CO_2的光电化学还原引起人们极大的兴趣,已有利用SiC粉末进行CO_2光催化还原的报道。本研究首次利用p-SiC膜光阴极还原CO_2,得到较高的CH_3OH产率。1 实验 在导电玻璃上采用水银光敏化CVD法制得微晶p-SiC膜,电极表面用4.6％HF溶液抛     

Heterogeneous reactions on the surface of fine particles in the atmosphere

Fine particles play an important role in the atmosphere. Research on heterogeneous reactions on the surface of fine particles is one of the frontier areas of atmospheric science. In this paper, physical and chemical characteristics of fine particles in the atmosphere and the interactions between trace gases and fine particles are described, methods used in heterogeneous reactions research are discussed in detail, progress in the study of heterogeneous reactions on the surface of fine particles in the atmosphere is summarized, existing important questions are pointed out and future research directions are suggested.     

表面活性剂与纳米SiO2作用下聚合铝的絮凝特性

在6NTU高岭土原水中,溶入低浓度溶解性有机物-阴离子表面活性剂(十二烷基硫酸钠,SDS),投加聚合铝PAC与新型水处理剂-纳米SiO2稳定分散液进行动态混凝实验与静止沉降实验.借助图像分析技术与分形理论,对SDS与纳米SiO2作用下PAC的絮凝特性与絮体分形结构的形态学特征进行研究.结果表明:存在SDS时,高岭土颗粒表面ζ电位增加.SDS在颗粒表面的吸附等温曲线符合Langmiur方程;PAC对无机颗粒的去除效果明显,但对SDS的表观去除率较低.SDS阻碍絮凝初絮体的形成.纳米SiO2使颗粒表面ζ电位增加,对无机颗粒处理效果较差,但对去除有机物有利.絮凝机理主要是吸附架桥;助凝剂纳米SiO2能促进PAC对无机颗粒与SDS絮凝,处理效果显著.悬浊液中絮体粒径大,有效质量密度增加,沉速加快,分维值下降.     

Sol-gel Method Synthesized Polyhedron SnO_2 Anode Material for Lithium Ion Battery

1 Introduction Tin-based oxides will be promising anode materials for lithium ion batteries due to its high specific capacity, low potential platform, and safety[1]. Many methods have been applied to synthesize SnO2 materials of different morphologies, such as chemical vapor deposition, spray, sol-gel method[2]. Triblock copolymer poly (ethylene oxide)-block-poly (propylene oxide)-block-poly (ethane oxide) (P123) has been used as surfactant to prepare nano-crystalline tin oxide particles[3]. In this pap...     

M+/SiO2型强碱性催化剂的制备及表征

以醋酸甲酯、甲醛为原料合成丙烯酸甲酯为探针反应,利用微反色谱实验装置,经过大量实验筛选出具有催化作用的K /SiO2型、Li /SiO2型碱性催化剂,其酯化率效果较好,并对其比表面积(BET)、孔径分布进行了表征和评价。     

乌鲁木齐二氧化硫污染成因分析及对策

文章通过对乌鲁木齐二氧化硫污染进行分析，得到乌鲁木齐市二氧化硫的城市中心区〉居民区、游憩区和文教区〉新市区的分布规律，乌鲁木齐特殊的地形地貌、气象气候条件和区域环境对二氧化硫污染的形成有重要作用.根据乌鲁木齐自身特殊的情况，提出相应的解决对策.     

煤与PVC共热解固体产物的红外光谱分析

通过红外光谱（IR）分析方法，对炼焦配煤与聚氯乙烯（PVC）共热解固体产物中有机基团及氯的形态进行了研究，并对实验样品进行溶解试验后的残留物进行了对比分析，结果表明，低温（500℃以下）热解产物中含有微量的有机氯，而且这些有机氯主要来源于未分解的煤，高温（600℃以上）热解产物中的氯全部以无机状态存在．     

二氧化碳在金属丝网的毛细动力学实验与分析

二氧化碳(CO2)作为制冷剂具有环保及良好的热力特性,已经越来越受到重视,并将率先应用在航天毛细驱动的两相循环冷却技术(CPL)和环路热管(LHP)中,但是由于它的工作压力较高,对其毛细动力特性研究还没有实验支持。文章的目标是通过实验测量CO2在不锈钢丝网爬升的动态结果,进行毛细上升的动力学分析,并将实验结果与几个经典的公式进行比较,找出最佳适用公式。     

Visible light photocatalytic decoloration of methylene blue on novel N-doped TiO2

Novel N-doped TiO2 (denoted as N-NTA600) was prepared by treating nanotube titanic acid (NTA) in NH3 flow. Its visible light photocatalytic activity,evaluated by decoloration reaction of methylene blue,is higher than that of N-P25(600) prepared by treatment of P25-TiO2 in the same condition. It is suggested that the origin of visible-light photocatalytic activity is single-electron-trapped oxygen vacancy (Vo·) modified by chemisorbed NO.     

超临界CO2萃取法与水蒸气蒸馏法提取广东海风藤挥发油成分的比较

分别采用超临界CO2萃取法和水蒸气蒸馏法对广东海风藤挥发油进行提取,用GC-MS法进行成分分析.超临界CO2萃取法提取物鉴定出25个成分,水蒸气蒸馏法提取物鉴定出31个成分,两者共有成分达21个.共有成分含量占超临界CO2萃取法提取物总量的81.48%,占水蒸气蒸馏法提取物总量的90.35%.