一种新型钛体系（Ⅳ）──α－酮酸钛酸酯与锂试剂的还原反应

一种新型钛体系（Ⅳ）──α－酮酸钛酸酯与锂试剂的还原反应段新方，尹承烈（北京师范大学化学系，北京，１００８７５）关键词加成，还原，钛酸酯，交换反应由于钛的优良调整作用，使得锂试剂ＲＬｉ不仅可以和α－酮酸钛酸酯ＡｒＣＯＣＯＯＴｉ（ＯＲ１）３中的酮发生加...     

具有超大通道结构的介孔氧化硅柱层状钛酸的合成和催化应用初探

A mesoporous (d=2.3mm) silica-pillared layered tetratitanate with a super gallery (d₀₀₁=1.84mm)was prepared by first preswelling layered tetratitanate with n-dodecyl amine, then reacting with 20wt% NH₂(CH₂)₃Si(OC₂H₅)₃ aqueous solution, and finally calcinating the resultant solid product in air at 550℃. All the reaction was carried out hydrothermally in an autoclave at 130℃. The obtained material has a relatively high BET surface area of 204m²·g^-1 and a thermal stability beyond 600℃. The catalytic application of the material was also investigated by using the dehydration of isopropanol and the reform of n-hexane as two probing reactions.     

表面活性剂在低能固体表面上的吸附 Ⅲ: 聚苯乙烯胶乳粒子对阴离子表面活性剂的吸附

在无乳化剂的条件下合成了粒径均匀的聚苯乙烯胶乳.发展了应用表面张力计测定吸附等温线的连续平衡法,得到不同盐浓度和温度下聚苯乙烯胶乳对十二烷基硫酸钠和十二烷基苯磺酸钠的吸附等温线.它们属于Giles分类的L_2型或L_4型,采用两阶段吸附模式讨论了吸附机理、吸附层结构及等温线类型变化的规律。     

纳米晶PbTiO3负载CuO催化NO分解

A large specific surface area perovskite-type mixed oxide PbTiO₃ supported cupric oxide was synthesized as a catalyst for NO decomposition and characterized by techniques such as XPS, XRD, H₂-TPR before and after NO decomposition reactions. The catalytic properties were tested with a fix-bed micro-reactor. The results showed that the PbTiO₃ was inactive for the reactions, but 1wt % Cu/PbTiO₃ catalyst gave fairly good activities for NO decomposition at temperature as low as 473 K. Copper species were found well-dispersed but weakly interacted with the support before NO decomposition, and the NO decomposition caused significant change in the environment of the copper species, which became Cu(Ⅰ) and most probably incorporated into surface crystal lattice of the nano-sized PbTiO₃. In NO reaction, a large amount of oxygen atoms from the decomposition of NO penetrated into the nano-sized PbTiO₃ support and caused small expansion of crystal lattice. The transport of oxygen between the copper species and the catalyst support may be helpful to speed up the kinetic regeneration of active metal sites from oxygen occupancy and resulted in good catalytic performance.     

N—烯丙基—N′（对苯磺酸钠）硫脲与钯（Ⅱ）的显色反应及其应用

1 引 言N－烯丙基－N′－(对苯磺酸钠)硫脲(以下简写为NaNTU)是我们合成的一种新的硫脲类衍生物,性质稳定,易溶于水,无毒,具有很好的分析特性。从我们研究的36种离子与NaNTU的反应情况看,在1.7～4.2 mol/L的HNO3溶液中,只有钯*"能与NaNTU生成黄色络合物。据此,我们成功地将其用于钯*"的鉴定,取得了很好的效果。在此基础上,将该试剂首次应用于钯*"的光度分析,从而建立了光度法测定微量钯*"的新方法。研究表明,在1.7～４．2mol/L的HNO3溶液中,Pd2+和NaNTU形成一种稳定的摩尔比为1∶2的黄色水溶性络合物。络合物的最大…     

超细粉Pb0.75Ca0.25[(Ni1/3Nb2/3)0.08Ti0.912Mn0.008]O3的制备与表征

报道了用化学共沉淀法制备掺杂Ca、Ni、Nb、Mn钛酸铅超细陶瓷粉末的方法。制得的粉料化学式为:Pb_0.75Ca_0.25[(Ni_1/3Nb_2/3)_0.08Ti_0.912Mn_0.008]O₃,粒径小于0.1μm,所有的掺杂元素均能定量掺入。     

纳米级NiTiO3粉体的合成

以Ｈ２ＴｉＯ３，Ｈ２Ｏ２及ＮｉＣｌ２为主要原料，用化学共沉淀法制备了纳米级ＮｉＴｉＯ３。确定了反应物Ｈ２ＴｉＯ３，Ｈ２Ｏ２，ＮＨ３的最佳摩尔比为１：８：２，用不同的退火温度和退火时间对样品处理得到相应粒径的纳米级粉体。     

荧光法直接测定环境水中十二烷基苯磺酸钠

在我国,十二烷基苯磺酸钠(SDBS)是使用量最大的洗涤剂之一,也是环境水中的一种污染物。检测SDBS常用的方法有:吸光光度法显色后一般需用有毒的有机溶剂萃取,操作繁琐;导数吸光光度法是采用四阶导数进行处理的测定方法,过程较复杂。本文用荧光分光光度法直接测定环境水中的SDBS含量,此法不需萃取和显色,通过控制溶液的pH值来进行测定,波长为λ_(ex)╱λ_(em)=230/290nm,干扰物少。