MoO_3、NiO、ZnO在小表面金红石上的分散行为

氧化物、盐类在氧化物载体表面的自发分散是一种广泛存在的现象，文献中已报导过大量氧化物和盐类在高比表面载体上分散的研究结果［'－3］TIO。作为一种较新型的载体，与Y－AI。O。、硅胶等传统载体相比，有许多不同特性．活性组分在TIO。表面的分散状态及所得催化剂的性能已有不少报导［'－'］，但所用的TIOZ主要是较高比表面的锐钛矿型TIOZ（刘金红石型TIO。（r）和锐钛矿型TIOZ（a）的结构不同，它是高温生成相，比表面较小［'］．氧化物在金红石上的分散行为仍未见报导．我们制备了三种具有不同比表面的TIO水），系统地研…     

复合固体超强酸催化剂SO_4~(2-)_4-WO_3-ZrO_2的结构研究

已报导，经适当处理的SO42-ZrO2和WO3－ZrO2具有超强酸性［1］．在此基础上将SO42-和WO3同时负载于ZrO2表面，发现其表面酸性有明显增强，得到的固体超强酸504－W0s－Zro。在很宽的焙烧温度范围内（700七00“C）都具有HO三一16．04的酸强度，吸附毗院的红外光谱研究表明，其表面同时具有强的L酸性和B酸性问，140“C时，对正乙烷裂解及异构化的催化活性比SO4－－ZrO。和WO3－ZI02都高，表现出相当的协同效应同．本文用XRD，DTA－TG，比表面测定等技术研究催化剂的组成、结构形态及其随焙烧温度的变化．并与504－Zro：和WO。…     

石墨炉原子吸收法直接测定高温合金中硅

研究了混合基体改进剂，灰北、原子化温度以及共存元素的干扰，采用镧和钙作混合基体改进剂后，硅的灵敏度提高，抗干扰能力增强，可以用石墨炉原子吸收直接测定高温合多中硅。方法特征量为０．２ｎｇ，检出限为２．３μｇ／ｇ，对于含硅量为４００μｇ／ｇ左右的合金样品，相对标准偏差为５％左右，回收率在９０％－１１０％之间。     

A novel approach to carbon hollow spheres and vessels from CCl4 at low temperatures

Carbon hollow spheres (400-600 nm) and vessels (400 nm x 3000 nm) have been synthesized from sp3-CCl4 at 190 and 230 degrees C, respectively. The HRTEM images and Raman spectra reveal the sp2 nature of the as-obtained products, indicating that the transformation from carbon sp3 to sp2 occurs in the reactions. The possible mechanism has also been proposed.     

土壤环境中铅的化学

论述了环境中铅的背景值、来源、污染、质量标准、化学循环以及环境中铅的烷基化，为铅污染治理提供理论依据。     

水杨酸与烟草铜锌超氧化物歧化酶的相互作用

利用邻苯三酚自氧化法监测了磷酸盐缓冲体系中水杨酸（SA）对超氧化物歧化酶（SOD）活力的影响。通过荧光光谱法研究了水杨酸与超氧化物歧化酶的相互作用机制，求得两者结合的形成常数和配位数，使用Forster非辐射能量转移技术求出了两者的结合位置距色氨酸残基间的距离为2.60nm。     

腙类配合物的研究——Ⅱ.二茂铁芳酰基腙和它们的一些过渡金属螯合物

通过甲酰基二茂铁与相应芳酰基肼的缩合反应合成了二茂铁基的苯甲酰基、对-甲氧基苯甲酰基和间-硝基苯甲酰基腙,并制备了它们与Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)和Mn(Ⅱ)醋酸盐的十种整合物。元素分析、IR和PMR谱的测定结果表明,这些金属有机配体是以烯醇式进行配位的。     

Methane Combustion Over Fe, Co and Ni Modified Manganese Oxide Catalysts

Fe-Mn, Co-Mn and Ni-Mn composite oxide catalysts based on high specific surface area MnO₂ precursor were prepared and applied to catalytic combustion of CH₄. Results were compared with that of unmodified MnOx and 1wt.% Pd/-Al₂O₃. Below 450°C, manganese oxide catalysts show higher activity than Pd/-Al₂O₃, while the modified manganese oxide catalysts exhibit higher activity than the unmodified one below 420°C. All catalysts were characterized by means of N₂-BET, XRD, TG-DTA and H₂-TPR. Due to the interaction between Fe, Co or Ni oxides and manganese oxide, the activity of the oxygen species of the modified catalysts is improved, which leads to the increase of their CH₄ combustion activity.     

12-钨磷酸希土盐DMF、DMSO加合物的合成、性质及其热分解动力学常数研究

合成了8种钨磷酸希土盐LnPW₁₂O₄₀·xH₂O(Ln=Y、La、Nd、Sm、Gd、Dy、Ho、Yb)的DMF、DMSO加合物,对加合物进行了组成分析,通过IR光谱、TG-DTA曲线对加合物进行了性质表征,并着重研究了加合物热分解过程的动力学,给出了热分解反应级数n和活化能E.     

Charge-transfer hybrids containing covalently bonded polyoxometalates and ferrocenyl units

Two new charge-transfer hybrids with one or two ferrocenyl units covalently attached to a hexamolybdate cluster through an extended pi-conjugated bridge have been prepared using Pd-catalyzed coupling reactions on monoiodo- or diiodo-functionalized cluster substrates in over 60% yields. These hybrids have been characterized by (1)H NMR, FTIR, electrospray ionization mass spectrometry, and X-ray diffraction. The electronic spectra of these hybrids show a broad absorption tail extending beyond 550 nm, indicating the existence of charge-transfer transition from the ferrocenyl donor to the cluster acceptor. The observation of the clear charge-transfer transition indicates the contribution of charge-transfer resonance to the ground state in both 2a and 2b even though the donor-acceptor separation distance of 11.29 A is rather long, signaling a through-bond charge-transfer nature made possible by the organic pi-conjugated bridge. Cyclic voltammetry studies reveal a one-electron oxidation wave and a one-electron reduction wave for the hybrid with one ferrocenyl unit. For the one with two ferrocenyl units, a lower reduction potential and a two-electron oxidation wave are observed, indicating negligible electronic interactions between the two ferrocenyl units.