硼改性Hβ-沸石上FCC轻汽油的醚化反应性能

研究了β－沸石对FCC轻汽油醚化反应的催化性能，考察了硼改性对Hβ－沸石的催化性能及表面酸性的影响，并用NH3－TPD和IR表征了改性后Hβ－沸石的表面酸性。实验结果表明，适量硼改性改善了催化剂的性能，提高了醚化反应活性；调变了催化剂的表面酸性，使得催化剂上弱酸中心的强度有所增加，强酸中心的强度略有下降，总酸量增加，且以L酸为主，L酸中心有利行醚化反应。     

固体超强酸（SO4^2-／ZrO2）的异丁烷／1-丁烯烷基化反应性能和失活研究

研究了固体超强酸(SO4^2-／ZrO2)催化剂的酸性及异丁烷-1-丁烯烷基化反应性能，结果表明，固体超强酸的酸性与焙烧温度有关，适当提高焙烧温度有利于样品酸强度的提高，但焙烧温度过高会导致脱硫，使样品酸强度和酸量降低，固体超强酸的异丁烷／1-丁烯烷基化催化反应活性与其酸性相对应，酸性强，反应活性高，但催化剂的活性衰减很快，这是催化剂表面的快速积炭所致。     

组合脱胺对β沸石酸性和结构的影响

利用ＴＰＤＥＴＰＤ和ＸＲＤ等手段研究了低温恒温脱胺后的再程序升温脱胺的组合脱胺法，结果表明，不同组合脱胺工艺均可调度β沸石的表面酸性，适当选择组合脱胺温度可大幅度调度β沸石的表面酸性，其中２７０℃和２９０℃下分别恒温脱胺后程序升温脱胺，β沸石表面除出现传统脱胺的两个酸性位外，还出现了一个中等强度的酸性位，且酸量很大，可调变性较强，晶相测定可知，低温脱后再程序升温脱妥有利于β沸石结晶度的保持，此外，     

LaHY表面与NaOH的作用及酸性表面性质研究

用正丁胺滴定和吡啶—红外光谱法,研究了LaHY表面上酸性中心与NaOH的作用机理及酸性表面性质。NaOH与LaHY表面上酸性中心作用的计量比与正丁胺滴定时不同。中和同样数量的酸性中心所消耗NaOH的当量数比正丁胺多,其差值与Lewis酸的含量有关。假定NaOH与LaHY表面上酸性中心作用的机理为:一当量Bronsted酸与一当量NaOH作用,而一当量Lewis酸消耗两当量NaOH,则可借助正丁胺滴定和NaOH中和法测定Bronsted酸和Lewis酸的含量。红外光谱测定的结果支持这一观点。 研究结果还表明,LaHY表面的酸性分布是不均匀的,异丙苯裂解反应是在不同强度的酸性中心上进行的。不同强度的酸性中心对总活性的贡献不同,而贡献的大小又与反应温度有关。     

温度对沸石酸性的影响

用红外光谱研究温度对沸石酸性的影响,结果表明,温度使沸石表面酸性(酸强度)增强,酸性增强的规律是大孔道或大孔腔中的酸性羟基>表面硅醇基(或缺陷羟基)>小笼中的酸性羟基,在所研究的温度范围内(290～510K)酸性随温度的变化呈线性关系。     

组合脱胺对β沸石酸性和结构的影响

利用ＴＰＤＥ、ＴＰＤ和ＸＲＤ等手段研究了低温恒温脱胺后再程序升温脱胺的组合脱胺法．结果表明，不同组合脱胺工艺均可调变β沸石的表面酸性，适当选择组合脱胺温度可大幅度调变β沸石的表面酸性，其中２７０℃和２９０℃下分别恒温脱胺后再程序升温脱胺，β沸石表面除出现传统脱胺的两个酸性位外，还出现了一个中等强度的酸性位，且酸量很大，可调变性较强．晶相测定可知，低温脱胺后再程序升温脱胺有利于β沸石结晶度的保持．此外，还对β沸石的脱胺过程和脱胺后β沸石的吡啶脱附过程的动力学行为进行了初步的研究．     

SAPO-34和SAPO-44分子筛上吸附甲醇的TPSR-MS研究

 采用程序升温表面反应-质谱(TPSR-MS)和程序升温脱附(TPD)技术考察了SAPO-34和SAPO-44分子筛表面的酸性与其催化甲醇转化为低碳烯烃性能的关系. 结果表明,SAPO分子筛表面存在两种活性中心,这两种活性中心与分子筛表面不同的酸性中心相对应. 表面吸附的甲醇在不同强度的酸性中心上进行不同的反应,在弱酸中心上主要进行甲醇脱水生成二甲醚的反应,在强酸中心上主要进行二甲醚进一步转化为低碳烯烃的反应. 同时,探讨了SAPO分子筛表面的酸强度对低碳烯烃生成温度的影响.     

活性基质在降烯烃渣油裂化催化剂中的应用

研究了渣油裂化催化剂的基质改性对催化剂性能的影响。结果表明，经高温及酸处理后，高岭土的孔容、比表面及其表面酸性明显增加；对拟薄水铝石进行磷改性，可增加氧化铝的表面酸性中心数目，降低酸强度。用改性的高岭土和氧化铝作为降烯烃渣油裂化催化剂的活性基质，可提高催化剂的渣油裂化及氢转移、异构化活性，并减少催化剂上的积碳。     

氟化γ-Al2O3表面酸性的NMR和FTIR表征

用红外光谱和核磁共振技术研究了氟化作用对γ-Al2O3的表面酸性（酸中心类型、强度及数量）的影响。吡啶和二甲基吡啶在氟化γ-Al2O3（F／γ-Al2O3）表面上吸－脱附的IR光谱和三甲基膦在F／γ-Al2O3表面上吸附的^31P MAS NMR结果表明，F／γ-Al2O3表面上既存在Lewis酸位又存在Broensted酸位。L酸的总量随氟含量的增加而减少。但其强度随之增加，且同时产生几种新的L酸位。B酸的数量和强度在样品含氟量为2％－3％间存在极大值。研究还表明，三甲基膦是一种测量F／γ-Al2O3表面酸性的灵敏的NMR探针分子，^31P MAS NMR和红外光谱的测试结果基本一致。同时，对氟化过程中酸位形成和变化机理进行了探讨。     

分子筛表面酸性对微波固相法制备ZnCl2/Y催化剂的影响

 采用XRD和原子吸收光谱法研究了微波作用下分子筛表面酸性对ZnCl2与Y分子筛固态相互作用的影响．结果表明，微波辐射可显著促进ZnCl2在分子筛表面分散，其分散阈值与分子筛表面酸性有关．随着分子筛表面酸量和酸强度增加，ZnCl2在分子筛表面的最大分散量减少，分散的ZnCl2与Y分子筛的固态离子交换量也减少；NaY型分子筛比HY分子筛更容易发生固态离子交换反应．考察了微波固相法制备的ZnCl2／HY催化剂在苯甲醚与乙酰氯酰化反应中的催化性能．结果表明，在分子筛表面分散的ZnCl2具有更高的催化活性及对甲氧基苯乙酮选择性．     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

化学计量中不确定度评定研究进展

测量不确定度是表征合理地赋予被测量之值的分散性的参数。本文针对化学计量不确定度评定基础模型仅适用于线性模型、概率分布为正态分布或缩放位移t分布等局限,介绍了近年来不确定度评定的研究热点:蒙特卡罗方法(Monte Carlo Method,MCM),不确定度评定的来源、评定概念、评估方法及其发展过程,扩大了测量不确定度评定与表示的适用范围。