Water vapor adsorption in activated carbon modified with hydrophilic organic salts

Five different kinds of hydrophilic organic salts were used to modify commercial activated carbon in order to prepare hydrophilic carbon materials. Properties of the samples were analyzed by surface area analyzer and SEM-EDX. The hydrophilic organic salts with different properties were introduced into activated carbon and significantly affected the properties of the samples.During adsorption experiments, the water vapor adsorption amount in modified samples increases by 0.57-17.12 times in temperature range from 303 to 323 K and at relative pressure below 0.50. Water molecules combined with surface hydrophilic groups through H-bonding exhibit good thermo stability. The effects of temperature, oxygen content and properties of the hydrophilic organic salts on water vapor adsorption were studied. It is indicated that water vapor adsorption in modified samples is mainly affected by the surface oxygen content. The carboxylate radicals in the hydrophilic organic salts greatly affect the micropore structure of the modified samples, while the metal ions in them exhibit limited influence. Different adsorption capacity of modified samples can be explained with the electronegativity of elements presented by Pauling.     

纳米二氧化硅的制备及在生物医学领域的应用

综述了近几年来纳米二氧化硅的一些主要制备方法,例如:St(o)ber法、模板法、微乳液法、气溶胶法.并且简述了纳米二氧化硅在抗菌剂、药物缓释等生物医学领域中的应用,以及纳米二氧化硅微球的浓度、粒径大小、表面性质等方面对纳米二氧化硅的生物安全性的影响.介绍了无定型纳米二氧化硅的毒性与其结构的关系,同时指出了单分散纳米石英颗粒的制备还存在许多亟待解决的难点.     

新型杀虫剂双三氟脲的合成

以间二三氟甲苯为起始原料,经发烟硝酸和浓硫酸硝化,铁粉还原和氯气氯化得到2-氯-3,5-二三氟甲基苯胺;2,6-二氟苯腈经质量分数30%的过氧化氢和质量分数5%的氢氧化钠溶液水解得到2,6-二氟苯甲酰胺,然后在二氯乙烷溶剂中与草酰氯反应得到2,6-二氟苯甲酰异氰酸酯.在室温条件下,2-氯-3,5-二三氟甲基苯胺与2,6-二氟苯甲酰异氰酸酯在甲苯溶剂中反应得到目的产物双三氟虫脲,收率为93.5%.经1H-核磁共振鉴定,产品结构与双三氟虫脲的结构一致.该工艺简单经济、条件温和,适合工业化生产.     

腐殖活性污泥生化特征及处理效能

为探讨腐殖活性污泥的生物化学特征及其作用机理,对腐殖生物填料进行扫描电镜和能谱(SEM-EDAX)测定,表明填料中主要组成元素为C、O、Si,同时含有少量Al、S、Fe. 腐殖活性污泥与普通活性污泥中若干特征菌群的对比分析表明,腐殖活性污泥中的一般细菌总量、硝酸菌、亚硝酸菌、脱氮菌及放线菌含量明显高于普通活性污泥;腐殖活性污泥中有机质的质量分数比普通活性污泥低,但腐殖酸及富里酸和胡敏酸质量分数明显高于普通活性污泥;腐殖活性污泥法运行的SBR反应器对CODCr、TP和TN的去除效果优于普通SBR反应器,分别高出4％、14％和10％．     

轮式探测车被动自适应性与自由度关系分析

为设计具有自适应性能的探测车,保证轮式探测车移动机构在行驶过程中车轮与地面接触良好,研究自适应性能与单侧悬架系统及其漫游车整体所需自由度之间的关系．给出自适应性的3种分类方法,分析自适应性能对漫游车的爬坡性能、车体稳定性能及能耗特性的影响;建立具有自适应性能的探测车单轮系统数学模型并得到此系统的自由度;分别建立包含两轮、三轮及k个车轮的自适应悬架系统数学模型,分析并得到上述系统所需的自由度;分别建立在悬架对称布置和四周布置两种情况下的探测车自由度模型,并对一些具有代表性的被动自适应特性探测车自由度进行了统计和分析．研究结果表明:良好的自适应性是实现移动机构综合性能的前提条件,具有自适应性的单侧悬架系统与探测车整体所需自由度分别为1和3．该方法可为探测车悬架及车体系统构型综合时自由度的确定提供指导．     

Synthesis and characterization of CePO4 nanorods via solvothermal process

One-dimensional cerium phosphate(CePO4) nanorods were successfully synthesized by a facile and simple solvothermal method at 150 ℃ for 12 h, using Ce(NO3)3·6H2O and NaH2PO4·2H2O as the starting materials. Phase and morphologie of the as-synthesized CePO4 products, characterized by XRD, FESEM, and TEM, were proved to be perfect and uniform hexagonal CePO4 nanorods with aspect ratio of more than 100. The photoluminescence(PL) spectrometer was used to investigate the optical properties of the assynthesized hexagonal CePO4 nanorods.     

Synthesis of calcium silicate hydrate based on steel slag with various alkalinities

This study aimed to improve the hydraulic potential properties of the slag. Therefore, a method of dynamic hydrothermal synthesis was applied to synthesize calcium silicate hydrate. The phases and nanostructures were characterized by XRD, FTIR, TEM, and BET nitrogen adsorption. The infl uence of alkalinity of steel slag on its structures and properties was discussed. The experimental results show that, the main product is amorphous calcium silicate hydrate gel with fl occulent or fi brous pattern with a BET specifi c surface area up to 77 m2/g and pore volume of 0.34 mL/g. Compared with low alkalinity steel slag, calcium silicate hydrate synthesized from higher alkalinity steel slag is prone to transform to tobermorite structure.     

Thermal Hydrolysis Synthesis and Characterization of Monoclinic Metahewettite CaV_6O_(16)·3H_2O

Monoclinic metahewettite CaV 6 O 16 ·3H 2 O has been fabricated via thermal hydrolysis of calcium vanadate(Ca 10 V 6 O 25). High purity calcium vanadate precipitate, featuring column structure with surface area of 8.61 m2/g, can be obtained by reacting sodium orthovanadate(Na 3 VO 4) with calcium oxide at 90 ℃ for 2 h. By acidifi cation of calcium vanadate in hot water at pH of 1.0-3.0, the monoclinic metahewettite crystals with uniform particle distribution, layered structure and nonporous structure can be fabricated. With the well crystallized layered structure, CaV 6 O 16 ·3H 2 O may be a potential cathode material for secondary batteries as well as super capacitor materials.     

NaEuF_4微米晶的水热合成与表征

以柠檬酸钠(Na3Cit)为螯合剂和形貌控制剂,通过水热方法成功合成了尺寸均匀的六角形NaEuF4微米晶.采用X-射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能量色散X射线(EDX)和光致发光光谱(PL)对所得产物的结构、形貌以及发光性质进行分析.XRD和SEM分析表明:所得NaEuF4微米晶为六方相,颗粒较均匀.NaEuF4微米晶的尺寸和形貌可通过改变Na3Cit的量和反应时间进行调整.提出NaEuF4微米晶的可能形成机理,并研究其光致发光光谱性质.     

Preparation of zeolite NaA for CO2 capture from nickel laterite residue

Zeolite NaA was successfully prepared from nickel laterite residue for the first time via a fusion-hydrothermal procedure. The structure and morphology of the as-synthesized zeolite NaA were characterized with a range of experimental techniques, such as X-ray diffraction, scanning electronic microscopy, and infrared spectroscopy. It was revealed that the structures of the produced zeolites were dependent on the molar ratios of the reactants and hydrothermal reaction conditions, so the synthesis conditions were optimized to obtain pure zeolite NaA. Adsorption of nitrogen and carbon dioxide on the prepared zeolite NaA was also measured and analyzed. The results showed that zeolite NaA could be prepared with reasonable purity, it had physicochemical properties comparable with zeolite NaA made from other methods, and it had excellent gas adsorption properties, thus demonstrating that zeolite NaA could be prepared from nickel laterite residue.