A study of mica structure and strength properties of polymer materials based on it

The mica microstructure is studied, and its shape and particle sizes are found as dependent on coating technology. Using epoxy and organosilicon polymers, several lots of materials with different contents of mica are prepared and mechanical tests are performed. The optimal amounts of mica wherein the initial strength characteristics are preserved are found. The thicknesses of epoxy and organosilicon polymer wherein high optical decorative properties of mica are preserved are determined.     

Structures, energetics, and spectra of hydrated hydroxide anion clusters

The structures, energetics, electronic properties, and spectra of hydrated hydroxide anions are studied using density functional and high level ab initio calculations. The overall structures and binding energies are similar to the hydrated anion clusters, in particular, to the hydrated fluoride anion clusters except for the tetrahydrated clusters and hexahydrated clusters. In tetrahydrated system, tricoordinated structures and tetracoordinated structures are compatible, while in pentahydrated systems and hexahydrated systems, tetracoordinated structures are stable. The hexahydrated system is similar in structure to the hydrated chloride cluster. The thermodynamic quantities (enthalpies and free energies) of the clusters are in good agreement with the experimental values. The electronic properties induced by hydration are similar to hydrated chloride anions. The charge-transfer-to-solvent energies of these hydrated-hydroxide anions are discussed, and the predicted ir spectra are used to explain the experimental data in terms of the cluster structures. The low-energy barriers between the conformations along potential energy surfaces are reported.     

Ionisation Energies and the Electronic Structures of the N-oxides of diazabenzenes

The ionisation energies and the HeI photoelectron spectra of the N-oxides of diazabenzenes are presented. The valence electronic structures of the N-oxides are discussed in view of the ionisation energies, and the profiles, of the bands. The interpreted data are compared to calculations which are in good agreement. The results are correlated to the physicochemical studies, and particularly to the electronic absorption spectroscopy, of the N-oxides. The assignment of the photoelectron spectra of the azabenzenes are considered with reference to the spectra of their N-oxides.     

Field Effects in Nematic Liquid Crystals in Terms of Catastrophe Theory

The field effects in nematic liquid crystal layers are reanalysed using catastrophe theory. The layer with pretilted director orientation and obliquely applied magnetic field, the hybrid aligned nematic cell and twisted nematic structures are considered. The stable solutions are identified and transitions between them are specified. The results are in essential agreement with previous work. Some details concerning the behaviour near the threshold are revealed.     

两种不同光谱类型的R-藻红蛋白的荧光性质研究

红藻中的R-藻红蛋白(R-PE)依照其吸收光谱可分为两种不同的光谱类型,即“双峰型”和“三峰型”。本文通过对不同pH条件下的R-PE的荧光光谱及荧光寿命的研究,发现“三峰型”R-PE的pH稳定范围较“双峰型”R-PE大。在R-PE浓度对荧光光谱的影响实验中,随着蛋白浓度的增加,荧光峰位置逐渐红移。荧光寿命逐渐增大,荧光强度先行增加而后减弱。用碘离子对其荧光进行猝灭,随着碘离子浓度的增大,荧光强度逐渐降低,荧光寿命逐渐缩短,并服从Stem-Volmer规则。     

钼、钨系过氧化物在Sharpless烯烃环氧化反应中的应用*

钼、钨系过氧化物是非常重要的Sharpless烯烃环氧化催化剂,有着非常广泛的工业发展前景。本文综述了钼、钨系过氧化物的种类,结构,合成方法及催化活性,分析了各种钼、钨系过氧化物的特点以及在催化环氧化领域的发展现状。同时,本文还讨论了钼、钨系过氧化物催化烯烃环氧化反应的机理。评述了在催化环氧化领域中两种主要理论——Mimoun机理与Sharpless机理的争论焦点及发展现状,以及计算化学对两种理论中间过渡态的研究进展,并且重点分析了Sharpless机理的过渡态结构。此外,本文还综述了影响钼、钨系过氧化物催化剂反应活性的各种因素以及质子所产生的副反应。最后,本文对应用于催化环氧化领域的钼、钨系过氧化物未来的研究方向提出了建议。     

Complexing properties of nucleic-acid constituents adenine and guanine complexes

Cobalt, nickel and copper complexes of adenine and guanine, as nucleic-acid constituents, were prepared. The adenine and guanine complexes are of tetrahedral and octahedral geometries, respectively. All are of high spin nature. The nickel complexes are of 2:1 metal:ligand ratio with Ni...Ni direct interaction in the guanine complex. The coordination bonds of adenine metal complexes are calculated and follow the order: Cu(II)-adenine < Ni(II)-adenine < Co(I)-adenine. The Cu(II)-adenine complex is the stronger following the softness of the copper, while that of guanine is less covalent. The copper complexes are with stronger axial field. The differential thermal analysis (DTA) and TGA of the complexes pointed to their stability. The mechanism of the thermal decomposition is detected. The thermodynamic parameters of the dissociation steps are evaluated. The complexes are of semi-conducting behaviour for their technical applications. Empirical equations are deduced between the electrical conducting and the energy of activation of the complexes.     

The characterization and structure-property relations of epoxies

The structure-deformation/failure process-mechanical property relations of epoxies used as matrices in high performance fibrous composites are presented. Such composites are fabricated either from fiber-epoxy prepregs or by filament winding. The parameters that affect the processing, cure reactions and the resultant chemical and physical structure of the epoxies are discussed. The deformation and failure processes of these glasses are described. The structural parameters that control the deformation and failure processes, the mechanical response and aging of epoxies are addressed and means of improving their processing and performance are described.     

介孔钛硅新催化材料

本文综述了介孔钛硅新催化材料的制备方法,归纳评述了各类介孔钛硅材料的制备技术和相应的产物的结构特点,介绍了现有的表征介孔钛硅材料孔结构和钛活性位的重要技术手段和特征,概括了含钛介孔材料在有机物液相催化选择氧化方面的应用,讨论了提高钛位的催化活性、结构稳定性、疏水性、钛硅比等的技术方法;提出了介孔钛硅材料研究存在的问题并展望了将来的研究方向。     

Water sorption on and water diffusion in chitin and chitosan

The kinetics of the sorption of water vapor on powders of crab-shell chitin and chitosan are studied via the methods of static sorption, thermography, and X-ray structural analysis. Sorption isotherms are obtained in the range of humidity from 10 to 95%. S-Shaped water-sorption isotherms observed for all chitin and chitosan samples are approximated via superpositioning of Langmuir and Flory-Huggins isotherms. The water-polysaccharide interaction parameters and the maximum sorption capacities of water located in chitin and chitosan are determined. The cluster integral is calculated, and the moisture values corresponding to water-cluster formation are determined. The water-diffusion coefficients are determined, and the effective activation energies of water diffusion are estimated: 70 kJ/mol in chitosan and 60 kJ/mol in chitin. The data on the concentration dependences of the coefficients of diffusion of water in the powdered chitin and chitosan are summarized.     

Field Effects in Nematic Liquid Crystals in Terms of Catastrophe Theory

Abstract

The field effects in nematic liquid crystal layers are reanalysed using catastrophe theory. The layer with pretilted director orientation and obliquely applied magnetic field, the hybrid aligned nematic cell and twisted nematic structures are considered. The stable solutions are identified and transitions between them are specified. The results are in essential agreement with previous work. Some details concerning the behaviour near the threshold are revealed.     

Coordination properties of hydralazine Schiff base Synthesis and equilibrium studies of some metal ion complexes

In the present study, a new ligand is prepared by condensation of hydralazine (1-Hydralazinophthalazine) with 2-butanon-3-oxime. The acid-base equilibria of the schiff-base and the complex formation equilibria with the metal ions as Cu(II), Ni(II), Co(II), Cd(II), Mn(II) and Zn(II) are investigated potentiometrically. The stability constants of the complexes are determined and the concentration distribution diagrams of the complexes are evaluated. The effect of metal ion properties as atomic number, ionic radius, electronegativity and ionization potential are investigated. The isolated solid complexes are characterized by conventional chemical and physical methods. The potential coordination sites are assigned using the i.r. and (1)H NMR spectra. The structures of the isolated solid complexes are proposed on the basis of the spectral and magnetic studies.     

稀土羧酸配合物的结构

本文系统地对200 多个稀土羧酸配合物的结构进行了归纳和总结, 重点对配合物的结构骨架、羧基的配位方式及稀土离子的配位数进行了讨论。     

Possible mediators of the "living" radical polymerization

The stable radicals derived from different compounds were detected in process of styrene autopolymerization. The nitroxide radicals are produced from nitrosocompound, hindered hydroxylamine, nitrophenols and nitroanisoles. The phenoxyl radicals are formed from quinine methides, and naphtoxyl radicals are generated from 2-nitro-1-naphtol. The radicals are identified, the kinetics of their formation and follow-up evolution are studied. These radicals can participate in process of living radical polymerization as the mediators and can effect significantly on kinetics of polymerization and structure of the resulting polymer.     

三氯锗丙酸及其衍生物自组装单分子膜的制备与表征

首次制备了三氯锗丙酸及其酯类衍生物(Cl₃GeCH₂CH₂COOC_nH_2n+1,n=0,2,4,6)在羟基化的单晶硅片上的自组装单分子膜,并利用接触角测量、椭圆偏振和光电子能谱法进行结构表征.结果表明,这类分子的自组装行为与三氯硅烷相似,组装后在基底表面形成准二维锗烷网状排布;分子链轴有一定倾斜角;膜表面润湿性随表征液体和三氯锗丙酸尾链取代基不同而不同.     

Electrostatic correlations in polyelectrolyte solutions

The major attribute of polyelectrolyte solutions is that all chains are strongly correlated both electrostatically and topologically. Even in very dilute solutions such that the chains are not interpenetrating, the chains are still strongly correlated. These correlations are manifest in the measured scattering intensity when such solutions are subjected to light, X-ray, and neutron radiation. The behavior of scattering intensity from polyelectrolyte solutions is qualitatively different from that of solutions of uncharged polymers. Using the technique introduced by Sir Sam Edwards, and extending the earlier work by the author on the thermodynamics of polyelectrolyte solutions, extrapolation formulas are derived for the scattering intensity from polyelectrolyte solutions. The emergence of the polyelectrolyte peak and its concentration dependence are derived. The derived theory shows that there are five regimes. Published experimental data from many laboratories are also collected into a master figure and a comparison between the present theory and experiments is presented.     

含有金属-金属键的双核原子簇离子体系[Mo~2Sn]^2-(n=6~9)的电子结构与电子光谱

使用SCF-CI方法研究了含有Mo-Mo单键的原子簇离子体系[Mo~2Sn](n=6~9)的电子结构及电子光谱。讨论了随n增加, 配体S, S~2, S~4对Mo-Mo键序、原子电荷的影响及其变化规律。分析了原子簇离子中的d-d相互作用能级次序及Mo-Mo, Mo-S'~t等键的性质, CI计算得到的谱带波数及强度次序与实验符合。指认分析表明, 谱带的跃迁性质是有趣的, 如第一吸收带为成键轨道之间的跃迁σ~x^2-y^2→σ~x~2(n=6~8), 同时, 对电子跃迁的性质进行了分类, 对谱带的电荷转移性质也进行了讨论。     

Optical, tsvetometric, and acid-base characteristics of methyl orange

The optical and tsvetometric characteristics of 4-dimethylaminoazobenzen-4′-sulphoacid (methyl orange, MO) in water solutions at pH 2–9 are studied. The equations of calibration plots of the dependence of colorimetric functions on concentration are obtained and calculated as molar coefficients of colorimetric functions. The method determines The constants of MO dissociation at an ionic force of 0.01–0.2 are determined by spectrophotometry; they are given to an ionic force of 0 and are compared to the literature data. The advantages of tsvetometry over spectrophotometry are shown in determining the MO concentration.     

Comprehensive ab initio calculation and simulation on the low-lying electronic states of TlX (X = F, Cl, Br, I, and At)

The low-lying electronic states of TlX (X=F, Cl, Br, I, and At) are investigated using the configuration interaction based complete active space third-order perturbation theory [CASPT3(CI)] with spin-orbit coupling accounted for. The potential energy curves and the corresponding spectroscopic constants are reported. The results are grossly in good agreement with the available experimental data. The absorption spectra are simulated as well to reassign the experimental bands. The present results are also useful for guiding future experimental measurements.     

有机成分标准物质的研究

列出了国家标准物质研究中心最近研制的有机成分标准物质。高纯度、定值准确可靠、良好的溯源性和系列性是这些标准物质的特点。对其应用作了介绍,并指出了将来的研究方向。