银纳米微粒共振散射光谱法测定羟基自由基及其应用

以柠檬酸三钠做还原剂,采用微波高压法制备了银纳米微粒。用高速离心纯化除去过量的柠檬酸三钠获得了纯银纳米微粒。纯银纳米微粒的共振散射峰位于470nm处。在pH4.0的HAc-NaAc缓冲溶液中,Fenton反应产生的羟基自由基可氧化银纳米微粒生成银离子,导致470nm处的共振散射光强度降低。过氧化氢的浓度在0.27-7.56gmol／L范围内与银纳米微粒470nm处的共振散射强度降低值△I470nm呈良好的线性关系,回归方程为△I470nm=24.3C＋13.8,相关系数为0.9959,检出限为0.23μmol／L。该方法用于筛选羟基自由基的清除剂,获得了满意的结果。     

小檗碱-Ⅰ3^-缔合微粒体系的光度分析应用

在稀HCl介质中,I-3在340 nm处有一吸收峰;当小檗碱(BB)与I-3共存时体系呈橙黄色,在580 nm处产生一共振散射峰.以试剂作参比,该缔合微粒体系在530 nm产生一吸收峰,BB浓度在0～7.0×10-5mol/L范围内与A530 nm呈线性,据此建立了一种测定小檗碱含量的分光光度新方法,并用于针剂样品中小檗碱测定,结果满意.同步散射光谱研究表明,BB+与I-3可通过静电引力作用形成疏水性的(I3-BB)缔合物分子,并进一步聚集形成稳定的(I3-BB)n缔合纳米微粒.由于该缔合纳米微粒在580 nm处产生共振散射效应,故体系呈橙黄色.     

小檗碱-I－3缔合微粒体系的光度分析应用

在稀HCl介质中,I-3在340 nm处有一吸收峰;当小檗碱(BB)与I-3共存时体系呈橙黄色,在580 nm处产生一共振散射峰.以试剂作参比,该缔合微粒体系在530 nm产生一吸收峰,BB浓度在0～7.0×10-5mol/L范围内与A530 nm呈线性,据此建立了一种测定小檗碱含量的分光光度新方法,并用于针剂样品中小檗碱测定,结果满意.同步散射光谱研究表明,BB+与I-3可通过静电引力作用形成疏水性的(I3-BB)缔合物分子,并进一步聚集形成稳定的(I3-BB)n缔合纳米微粒.由于该缔合纳米微粒在580 nm处产生共振散射效应,故体系呈橙黄色.     

碳纳米微粒的共振散射光谱研究

液相碳纳米微粒的共振散射光谱实验表明,当碳浓度小于360mg/L时,它在400、470、510和940nm产生4个共振散射峰;浓度大于900mg/L时无共振散射、碳微粒浓度在0．45－45mg/L范围内与共振散射光强度I470nm成良好的性关系,研究了光源和扫描速度对液相碳纳米微粒共振散射光谱的影响。结果表明,光源的发射强度分布不一是产生共振散射光谱峰的一个重要因素,并结合已有的实验结果提出了界面共振吸收和黑白纳米微粒共振散射概念,解释了碳纳米微粒体系的共振散射光谱。     

四苯硼钠-甲苯胺蓝缔合物纳米微粒体系减色效应研究

在PH4.0醋酸-醋酸钠介质中，甲苯胺蓝在600nm处有一个吸收峰，随着四苯硼钠浓度的增大甲苯胺蓝在600nm处吸收峰降低，颜色减弱，这是由于甲苯胺蓝-四苯硼钠缔合物分子间存在较强的疏水作用及分子间作用力，聚集形成纳米微粒所致，甲苯胺蓝-四苯硼钠纳米微粒体系亦在600mm处有1个吸收峰，在400mm、470mm和580mm处产生3共振散射峰，其中400mm和580mm为甲苯胺蓝-四苯硼钠复合纳米微粒产生的特征共振散射峰，这也表明有纳米微粒存在，丙酮浓度的影响实验结果等表明，纳米微粒的形成是产生其减色效应的原因。     

液相卤化银纳米微粒的界面荧光和共振散射光谱特性

液相卤化银纳米微粒的共振散射光谱和发射光谱表明,AgCl和AgBr纳米微粒均在330,400,470和680nm处产生4个共振散射峰,在340,400和470nm处产生三个荧光峰．Ad纳米微粒在340,400,437,470和680nm处产生5个共振散射峰;除在340,400和470nm处产生3个荧光峰外,在434nm处有一最强的荧光峰．卤化银纳米微粒体系的浓度对共振散射信号的影响与浓度对荧光强度的影响一致,Aga,AgBr和AgI体系的共振散射光信号强度分别约为荧光信号的110,130和80倍,即荧光与共振散射之间存在相关性．提出了液相AgX纳米微粒荧光产生机理,解释了荧光与共振散射之间存在相关性的原因．     

小檗碱-I_3~-缔合微粒体系的光度分析应用

在稀HCl介质中,I_3~-在340 nm处有一吸收峰;当小檗碱(BB)与I_3~-共存时体系呈橙黄色,在580 nm处产生一共振散射峰。以试剂作参比,该缔舍微粒体系在530 nm产生一吸收峰,BB浓度在0～7.0×10~(-5)mol/L范围内与A_(530nm)呈线性,据此建立了一种测定小檗碱含量的分光光度新方法,并用于针剂样品中小檗碱测定,结果满意。同步散射光谱研究表明,BB~+与I_3~-可通过静电引力作用形成疏水性的(I_3-BB)缔合物分子,并进一步聚集形成稳定的(I_3-BB)_n缔合纳米微粒。由于该缔合纳米微粒在580 nm处产生共振散射效应,故体系呈橙黄色。     

氯金酸-罗丹明S缔合纳米微粒体系的共振散射增强与荧光猝灭研究

在0．2mol/L HCl介质中，罗丹明S(RDS)分别在520nm和550nm处有一个吸收峰和荧光峰。当有Au(Ⅲ）存在时，Au（Ⅲ）与Cl^-形成AuCl4^-，AuCl^-与RDS^ 借助于静电引力形成疏水性的AuCl4-RDS缔合物分子。AuCl4-RDS分子间存在较强的分子间作用力和疏水作用力而生成(AuCl4-RDS)。缔合纳米微粒，粒径为45nm。在360nm产生瑞利散射峰，在600nm产生共振散射峰。由于纳米微粒形成后，只有裹露在(AuCl4-RDS)n纳米微粒界面的RDS荧光分子才能吸收激发光子跃迁到激发态，进而返回基态产生荧光。而体相的RDS荧光分子无法与激发光作用产生荧光，即受激RDS分子数大为降低，故550nm荧光峰和520nm吸收峰的降低。当缔合纳米微粒体系加入乙醇后，体系的红紫色和共振散射峰消失，吸收峰和荧光峰恢复，由于乙醇致使(AuCl4-RDS)。纳米微粒分解为AuCl4-RDS分子。结果表明：红紫色(AuCl4-RDS)n纳米粒子的形成是其共振散射增强、荧光猝灭和产生共振散射峰的根本原因。     

(PtI6-2RDG)n缔合纳米微粒体系的共振散射、荧光猝灭和减色效应研究

在0.02mol/L HCl介质中，罗丹明6G（RDG）分别在530nm和550nm处有一个吸收峰和荧光峰，PtI6^2-与RDG^ 主要通过静电引力形成疏水性的PtI6-2RDG缔合物分子。PtI6-2RDG分子间存在较强的分子和和疏水作用力而生成（PtI6-2RDG)n缔合纳米微粒，其粒径为40nm，在400nm、470nm和590nm产生3个共振散射，其中400nm和590nm处的2个峰为其特征共振散射峰，550nm荧光峰和530nm吸收峰的降低是由于纳米微粒形成后，只有裹露在（PtI6-2RDG)n纳米微粒界面的RDG荧光分子才能吸收激发光子跃迁到激发态，进而返回基态产生荧光，而体体相的RDG荧光分子无法与激发光作用产生荧光，即与激发光作用的RDG分子数大为降低。当该纳米微粒体系加入乙醇后，由于乙醇致使（PtI6-2RDG)n纳米微粒分解为PtI6-2RDG分子，体系的红紫色和共振散射峰消失，吸收峰和荧光峰恢复，研究结果表明，红紫色（PtI6-2RDG)n纳米微粒的形成是其共振散射增强、荧光猝灭、减色效应和产生特征共振散射峰的根本原因。     

核酸适体修饰纳米金-钌催化共振散射光谱法测定痕量Pb2+

用铅离子的特异性核酸适体（aptamer）修饰AuRu复合纳米微粒（AuRu的摩尔比为5:1）制备了铅离子的核酸适体纳米探针（AptAuRu）.在pH 7.0的Na2HPO4-NaH2PO4缓冲溶液及85 mmol/L NaCl存在下,AptAuRu纳米探针亦不聚集. 当Pb2+ 存在时,Pb2+可与探针中的aptamer形成较稳定的G-四分体结构,从而析放出AuRu复合纳米微粒并进一步聚集形成较大的微粒,导致592 nm处的共振散射光强度线性增大. 该反应液经0.15 μm滤膜过滤后,获得未反应的AptAuRu滤液. 滤液中的纳米微粒对氯酸钠-碘化钠反应具有较强的催化作用,其产物与阳离子表面活性剂形成缔合微粒,在472 nm处有一较强的共振散射峰. 随着Pb2+浓度增大,滤液中金钌纳米微粒浓度降低,其催化作用减弱,共振散射强度值降低. Pb2+浓度在0.12～60 pM范围与其共振散射强度降低值ΔI472nm呈线性关系,回归方程、相关系数分别为ΔI472nm =3.1C+7.3,0.9967, 检出限为0.08 pM Pb2+. 将本法用于废水中Pb2+的检测,其结果令人满意.     

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.     

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。     

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.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Investigation of Kinetics of Solid-Phase Synthesis of Lithium Orthosilicate

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m²g^-1 instead of aerosil with one of 175 m²g^-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.     

小环化合物中饱和碳质子化学位移的计算

小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.