几种抗结核药的应用

论述了四类抗结核药物的应用，着重讨论了利福平、氧氟沙星、力排肺疾等的应用。     

Some aspects of the enthalpy of dilution of biological polyelectrolytes

It is shown that calorimetric experiments on the dilution process of polyelectrolytes, i.e. on the excess enthalpy of electrostatic origin, can give information on the conformational state of the polymer. Analytical expression are obtained relating the enthalpy of dilution to the charge density on the polymer, from Manning's theory. The experimental data reported on some ionic biopolymers are interpreted on the basis of the theoretical prediction of the electrostatic contribution to the enthalpy of dilution in water of a polyelecrolytic salt and of a weak polyacid. The procedure outlined provides a means of calculating the actual charge/per unit length and of disclosing possible non-electrostatic effects arising from conformational transitions.     

我国稀土生物无机化学研究进展

我国稀土生物无机化学研究的特点是紧密结合稀土在农用及药物中应用所提出急需回答的问题, 经过长期的工作, 已在稀土的跨细胞膜运转, 稀土进入动物体内后的物种分布, 稀土与细胞膜的作用, 稀土对血红蛋白结构与载氧功能的作用, 稀土对骨细胞及骨结构的影响以及稀土在大鼠肝脏中的积累等方面取得了满意的结果. 从而可以为今后开展稀土元素在农用及药用中危险性评价的基础数据, 同时亦将促进稀土细胞化学的发展.     

Interpretation of longitudinal-acoustical-mode spectra of polymers

The influence of temperature, frequency, and straight-chain-length distribution on the low-frequency Raman-active longitudinal-acoustical-mode (LAM) bands of polymers is discussed. Specifically, the effect of these factors on the intensity of LAM-1, on the ratio of intensities of LAM-1 to LAM-k, and on peak position is computed or estimated. Band halfwidth and chain-length-distribution halfwidth are found not to be simply related. It is shown that the integrated intensity of LAM-1 is very nearly proportional to the total length of straight chains.     

Spreading kinetics of water drops on self-assembled monolayers of thiols: significance of inertial effects

Spreading of 5-15 microL water drops on self-assembled monolayers of 1-hexadecanethiol and 11-mercapto-1-undecanol, both homogeneous and mixed compositions, formed on gold-coated silicon wafers or glass slides was recorded with a high-speed video camera. The time (t) evolution of the drop base diameter (D) during spreading was analyzed by a power law-correlation: D approximately t(n). The n value was found to increase from n = 0.3-0.5 for water drops on hydrophobic surfaces characterized by the advancing water contact angle of thetaA = 94-104 degrees to n = 0.5-0.8 on less hydrophobic surfaces (thetaA = 45-66 degrees ). These experimental values were found to be of similar magnitude as the literature values reported for small drops and bubbles, which spread over a variety of different substrates including water and water-ethanol drops on self-assembled monolayers of alkylsilanes, air bubbles in water on glass, molten metals on solid metals and ceramics, hydrocarbon drops on water, and others. Inertial effects, which are often not accounted for in the analysis of spreading results, appear to have an impact on the spreading kinetics of small drops in at least the first few milliseconds of the spreading phenomenon.     

Molecular statistical calculation of thermodynamic characteristics of adsorption of polymantane molecules on the basis face of graphite

The thermodynamic characteristics of adsorption (TCA) of polymantane molecules and their some derivatives on the basis face of graphite were calculated for the first time in terms of the atom-atomic approximation of the semiempirical molecular statistical theory of adsorption. The graphite surface exhibits high structural selectivity to isomeric polymantanes. A model for adsorption of cage molecules on the planar surface was proposed. The model is based on the idea that contributions of atoms of the adsorbate molecule to the total adsorption energy can be discriminated according to the distance of these atoms from the surface of a solid. Advantages and limitations of using the data on adsorption of molecules of isomeric alkanes, including rotamers, for the analysis of equilibrium TCA values of isomeric polymantanes on graphite are discussed. The possibility of separation of representatives of the polymantane hydrocarbon family by gas adsorption chromatography on columns with graphitized thermal carbon black was suggested on the basis of the calculated TCA values and logarithmic retention indices.     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...     

Selectivity of the membrane action of a cytotoxin from the venom of the Central Asian cobra

It has been shown that the selectivity of the direct hemolytic effect of the cytotoxin on different erythrocytes correlates with its influence on the ionic permeability of the membranes of these erythrocytes. It has been established on bilayer phospholipid membranes that the influence of the cytotoxin on their ionic permeability depends on the amount of cholesterol in them. It is assumed that the resistance of the cells to the cytotoxin is determined by the stability of the phospholipid backbone of their membranes.     

Microstructural investigations of surfaces of destruction of carbon plastic

Results of endurance tests of microplastic on the basis of carbon fiber and epoxy binding, as well as data of microstructural analysis of the surfaces of destruction, are presented. Based on the obtained results, an attempt was made to classify the main types of damage. The dependence of the mechanism of the destruction process on the deformation properties of bindings was found.     

Thermodynamics of micellization of tetraethylammonium perfluorooctylsulfonate in water

Conductivity, density, and sound velocity measurements as functions of temperature were made on tetraethylammonium perfluorooctylsulfonate solutions to determine the Krafft point, the dependence on temperature of the critical micelle concentration, the micellar ionization degree, and several thermodynamic properties: Gibbs free energy, enthalpy and entropy of micellization, apparent molar partial volume, thermal expansion coefficient, and the adiabatic compressibility factor of both micellized and unmicellized surfactants. Important changes occur at about 30 degrees C. Results are interpreted on the basis of dehydration of surfactant on micellization and on temperature increase.     

寡聚脱氧核苷酸吸附状态随电位的变化

利用原位电化学及表面增强拉曼散射（SERS）光谱方法对寡聚脱氧核苷酸（26-mers ODN和13-mers ODN）在银电极表面上的吸附状态进行了研究. 实验表明, 单链寡聚脱氧核苷酸在银电极上有很好的SERS光谱,单链寡聚脱氧核苷酸在银表面上主要以碱基腺嘌呤（A）为吸附点,吸附状态随电位变化而变化, 链长较短的寡聚脱氧核苷酸在银电极表面的吸附态对电位变化较敏感.     

Investigation of acid-base and sorption properties of surface of metal–ceramic composites

The acid-base properties of the surface of composites based on boron, silicon, and sialon nitrides were investigated by the indicator method of Hammett and Tanabe with spectrophotometric indication. Identification of the surface sites of the composites under study was carried out. On the surface of composites based on boron and sialon nitrides the Lewis base sites dominate, while on the surface of samples based on silicon nitride the Brønsted acid sites. Sorption of dyes and oxalic acid by cermet materials was studied. It is shown that the adsorption activity depends on the nature and amount of surface active sites of the composites.     

催化裂解CH4制备碳纳米管的影响因素

以柠檬酸法制备的Fe-MgO、Co-MgO和Ni-MgO为催化剂,CH4为碳源气,H2为还原气,在873、973和1073 K制备出碳纳米管,通过TEM和拉曼光谱表征,讨论了催化剂、制备温度、反应时间等因素对碳纳米管形貌、产率和内部结构的影响.结果表明:不同的催化剂在相同的温度下制备的碳纳米管的形态和内部结构有很大的差异.其中Fe-MgO催化剂制备的碳纳米管管径粗,且大小不均匀,而Ni-MgO催化剂制备的碳纳米管管径较细、较均匀.碳纳米管的产率随着裂解温度的变化而改变.Fe-MgO催化剂制备碳纳米管的产率随制备温度的升高而提高,而Ni-MgO催化剂制备碳纳米管的产率随制备温度的升高而降低.Fe-MgO催化剂制备碳纳米管,在1073K甚至更高的制备温度才能达到其最高产率.Co-MgO催化剂制备碳纳米管的产率在973 K左右产率较高,而用Ni-MgO催化剂制备碳纳米管,则在873 K甚至更低的制备温度就能达到最高产率.反应时间与碳纳米管的产率不成正比,有一最佳反应时间,如Ni-MgO催化剂的最佳反应时间为2 h.     

Photoinduced graft polymerization of acrylic acid on the surface of polypropylene films from a thin layer of nondeaerated aqueous solution of the monomer

Photoinduced graft polymerization of acrylic acid on the polypropylene film surface containing a preliminarily adsorbed photoinitiator (benzophenone) from a thin layer of a nondeaerated aqueous solution of the monomer, isolated from the contact with atmospheric oxygen, was studied. Data were obtained on how the amount of the grafted polymer and the wetting angle for water on the film surface depends on the duration of the UV irradiation and on the monomer solution layer thickness. These data are compared with the results previously obtained for the photoinduced grafting of polyacrylic acid on polyethylene films.     

Development of a procedure for the determination of X-ray fluorescence of metals in aerosols

The precision of the determination of the of heavy metals in aerosols by X-ray fluorescence after their collection on a paper filter is evaluated depending on the chemical composition and weight of unsaturated samples. Recommendations on the choice of the optimal shape of the calibration function and on the conditions for the determination of its coefficients used for the X-ray analysis of unsaturated samples are formulated. A procedure for the X-ray determination of metals in aerosols collected on paper filters is developed; its performance characteristics are presented.     

Influence of the precursors on the properties of alumina supported rhodium particles

The effect of chlorine on the properties of Rh particles supported on alumina was studied using the hydroconversion of alkanes as a molecular probe. Chloride ions on the alumina have little influence on the Rh particles. Chlorine adsorbed on the Rh particles decreases the chemisorption capacity and increases the metal-support interaction, which results in modifications of their catalytic properties. Depending on the alkane processed, specific activity can be depressed up to four orders of magnitude.     

Detailed process of adsorption of alkanes and alkenes on zeolites

The adsorption of alkanes and alkenes on zeolites is investigated by comparing the adsorption characteristics for three types of zeolite: ferrierite, ZSM-5, and mordenite. The activation energy for the diffusion of propane and n-butane on ferrierite and the heat of adsorption of C(2)-C(4) alkanes and alkenes on zeolites and silica are estimated based on Fourier transform infrared spectroscopy, and the diffusion processes in the micropores are elucidated by comparing the results with previously reported activation energies for n-butene diffusion. The adsorption of 1-butene on mordenite is also examined. The structure and process of experimentally observable adsorption is found to differ depending on the type of zeolite and adsorbing molecule, reflecting differences in the sizes of molecules and pores. This differing behavior is utilized to interpret the elementary adsorption processes of alkanes and alkenes on zeolites.     

Influence of temperature and pressure on the preferential adsorption of component of hydroorganic mobile phase in liquid chromatography

The excess isotherms of methanol and acetonitrile were measured on the series of C18 bonded phases. The measurements were done using the minor disturbance method. The goal of our work was to determine the influence of the temperature on the adsorption of two commonly used solvents. The influence on the mobile phase flow rate on the both organic solvent adsorption was also investigated. The effect of these two parameters was compared on the octadecyl packed columns with different coverage density and on the monolithic Chromolith column. Adsorption of both solvents decreases with the increase of the temperature. The increase of the pressure increases adsorption of methanol but decreases adsorption of acetonitrile.     

Peculiarities of microweighing of trace quantities of alkylamines on polymer and solid-state thin films

The development of various devices with sensing elements operating on the basis of quartz crystal microbalance technique for the determination of ammonia and volatile amines in air have been considered. The results on the formation of selective layers of piezoelectric sensors with the specified properties have been presented. The influence of the nature of modifier, solvent, sorbate, and method of their formation on the piezo element on the sorption properties of thin films has been considered. The mechanism of interaction in the studied systems has been discussed relying on the results of quartz crystal microbalance measurement and microstructural studies at different stages of sorption.     

季铵阳离子对木质素减水剂性能的影响

以木质素磺酸钙为原料 ,通过离子交换法制备了五种季铵阳离子木质素磺酸盐 ,系统的研究了它们对水泥各项性能的影响。研究结果表明 :不同季铵阳离子所对应的木质素磺酸盐在应用性能上存在明显差异 ,有些木质素磺酸季铵盐显示出新的应用潜力。