聚电解质溶液中2.6-ANS探针的荧光谱研究

本文合成了2.6—ANS荧光探针分子,并在含有不同外加盐的NaPSS溶液中测定了探针的荧光发射光谱。结果表明:探针的荧光强度随Cs增大而增大,而探针光谱的最大发射波长和半波宽度随Cs增大而减小。当Cs达到一定值时,荧光谱参数与Cs关系曲线出现转折点,此时聚离了链以“类胶束”状态存在。     

Electrical Potential Distribution around a Charged Colloidal Particle: Nonlinear Integral Equation

多电解质溶液中带电胶体粒子的电势分布由球形Ｐｏｉｓｓｏｎ－Ｂｏｌｔｚｍａｎｎ方程（ＰＢＥ）描述．ＰＢＥ是一个非线性的微分方程，且难以求得其解析解．本文采用非线性Ｐ－Ｂ积分方程，计算电势分布的数值解．首先，根据静电场和热力学系统中的物理定理，导出描述电势分布的Ｐ－Ｂ积分方程（ＰＢＩＥ）；其次，用迭代方法求ＰＢＩＥ的数值解．最后，计算了在３－１型电解液中无量纲半径κａ分别为０．１２和０．２２，无量纲表面电势ξ分别为１，２，４，６时球形胶体粒子外部的电势值．为了检验数值解的精度，计算了表面电荷密度，并与Ｌｏｅｂ（１９６１）和Ｏｓｈｉｍａ（１９９５）等人的结果比较，本文结果的相对误差小于１％，优于Ｏｓｈｉｍａ的结果．     

Ab initio study of the complexes of halogen-containing molecules RX (X=Cl, Br, and I) and NH3: towards understanding the nature of halogen bonding and the electron-accepting propensities of covalently bonded halogen atoms

Ab initio calculations have been performed on a series of complexes formed between halogen-containing molecules and ammonia to gain a deeper insight into the nature of halogen bonding. It appears that the dihalogen molecules form the strongest halogen-bonded complexes with ammonia, followed by HOX; the charge-transfer-type contribution has been demonstrated to dominate the halogen bonding in these complexes. For the complexes involving carbon-bound halogen molecules, our calculations clearly indicate that electrostatic interactions are mainly responsible for their binding energies. Whereas the halogen-bond strength is significantly enhanced by progressive fluorine substitution, the substitution of a hydrogen atom by a methyl group in the CH(3)X...NH(3) complex weakened the halogen bonding. Moreover, remote substituent effects have also been noted in the complexes of halobenzenes with different para substituents. The influence of the hybridization state of the carbon atom bonded to the halogen atom has also been examined and the results reveal that halogen-bond strengths decrease in the order HC triple bond CX > H(2)C=CHX approximately O=CHX approximately C(6)H(5)X > CH(3)X. In addition, several excellent linear correlations have been established between the interaction energies and both the amount of charge transfer and the electrostatic potentials corresponding to an electron density of 0.002 au along the R-X axis; these correlations provide good models with which to evaluate the electron-accepting abilities of the covalently bonded halogen atoms. Finally, some positively charged halogen-bonded systems have been investigated and the effect of the charge has been discussed.     

Preparation of solutions of amidomagnesium chlorides in poly(ethylene oxide) and their characterization by conductivity measurements

Polymer electrolyte systems were prepared for the first time by dissolution of amidomagnesium chlorides in poly(ethylene oxide), (PEO). For the preparation, solutions of (hexamethyldisilylamido)magnesium chloride, (dimethylpyrrolyl)magnesium chloride, (diisopropylamido)magnesium chloride, piperidinomagnesium chloride and morpholinomagnesium chloride were chosen. The composition of these polymer electrolyte systems corresponds to the general formula R₂NMgCl·P(EO)_n·THF. Most work has been done with the system (hexamethyldisilylamido)magnesium chloride in PEO, (Me₃Si)₂NMgCl·P(EO)_n·THF, with n= 3, 4, 5, or 7. The electrolytes have a soft rubber-like consistency. At 30 °C, electrical conductivities of 10⁻⁶–10⁻⁵ S/cm were found. The conductivities were measured in the temperature range 20–60 °C. Within this temperature range a linear dependence of the logarithms of the conductivity on the inverse temperature was found and activation energies for the conducting process of 30–60 kJ/mol were calculated. Using those polymer electrolytes with a high content of the amidomagnesium compound, a reversible magnesium deposition takes place by cathodic reduction at potentials below −1.9 V vs. a Ag/AgCl reference electrode. These polymer electrolytes were found to be stable against oxidation up to about −0.3 V vs. Ag/AgCl. Electronic Publication     

Simple evaluation of Franck–Condon factors and non‐Condon effects in the Morse potential

The calculation of Franck–Condon factors between different 1‐D Morse potential eigenstates using a formula derived from the Wigner function is discussed. Our numerical calculations using a simple program written in Mathematica are compared with other calculations. We show that our results have a similar accuracy as those calculations performed with more sophisticated methods. We discuss the extension of our method to include non‐Condon effects in the calculation. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 88: 280–295, 2002     

APPLICATION OF MSW-X_α METHOD WITH OVERLAPPING ATOMIC-SPHERE TO IONIZATION POTENTIALS FOR SOME PLANAR ORGANIC MOLECULES

Application of multiple scattered-wave X_α method with overlapping atomic-sphere to ionization potentials is reported for benzene, pyridine, pyrazine, pyrrole and imidazole. The calculated results show that the orbital charges in the intersphere region are non-negative and the energy levels get improvements in orderings.     

Studies on the Spectral Behavior between Protein with Poniacyl Carmine 2B and its Analytical Application

In this paper, the spectral behavior of protein and Poniacyl Carmine 2B (PC 2B) has been studied by spectrophotometric method. The conditional constants, apparent combination constant K and maximum binding number n, were used to express the combination ability of the reactions between PC 2B and protein under a set of given conditions. The Sandell index s was used to express the sensitivity of the determination of protein. The factors, acidity, PC 2B concentration and the ionic strength, were discussed by the change of apparent combination constant and maximum binding number. It was found that acidity of the solution, PC 2B concentration and ionic strength had a significant effect on the sensitivity of the assay of protein. Under the optimal conditions, the apparent combination constant K and the maximum binding number n were 2.36 × 10⁶ L mol^?1 and 95, respectively. With further investigation, it was found that the Scatchard model was suitable in treating the data obtained in the experiments. In the buffer medium of HCl‐KCl at 1.87, the addition of protein made the maximum absorption of the system move from 527 nm to 513 nm. Its apparent molar absorptivity is 4.46 × 10⁵ Lmol^?1 cm^?1 at 513 nm. Beer's law is obeyed in the range of 0 ? 55 μg mL^?1. The system developed in this paper has been used for the determination of protein in milk powder successfully.     

Neutral oxygen atom density in the MESOX air plasma solar furnace facility

The density of neutral oxygen atoms in the MESOX set-up, one device of the PROMES-CNRS solar facilities, was determined by a fiber-optics catalytic probe (FOCP). Plasma was created in a flowing air within a quartz tube with the outer diameter of 5 cm by a 2.45 GHz microwave generator with the output power up to 1000 W. The flow of air was varied between 4 and 20 l/h. The O-atom density was found to increase monotonously with the increasing discharge power, and it decreased with the increasing flow rate. The degree of dissociation of oxygen molecules in the plasma column depended largely on the flow rate. At the air flow of 4 l/h it was about 80% but it decreased to about 20% at the flow of 20 l/h.