连接性指数与Kov(a)ts指数的相关性研究

在分子拓扑理论的基础上,提出一种新的拓扑指数——连接性指数~mG,其中。计算了12个系列94种分子的~0G、~1G值,发现~0G或~1G与这些化合物的Kovts指数具有很好的相关性。该模式计算方法简单,使用方便,预测结果理想。     

高锰酸盐指数的灰色GM(1,1)预测

以中山市岐江河近7年的高锰酸盐指数监测数据为基础，采用灰色系统理论中的预测方法，建立了岐江河高锰酸盐指数的灰色预测模型。用该模型预测岐江河2006年、2007年、2008年高锰酸盐指数的值分别为5．3，5．4和5．4。     

Densities, refractive indices and speeds of sound of the ternary mixtures (dimethyl carbonate + methanol + ethanol) and (dimethyl carbonate + methanol + 1-propanol) at T=298.15 K

Density, refractive index and speed of sound at T=298.15 K and atmospheric pressure have been measured over the entire composition range for (dimethyl carbonate (DMC) + methanol + ethanol) and (DMC + methanol + 1-propanol). Excess molar volumes, changes of refractive index on mixing and deviations in isentropic compressibility for the above systems have been calculated. The calculated quantities are further fitted to the Cibulka equation to estimate the ternary fitting parameters. Standard deviations from the regression lines are shown.     

Refractive Indices, Densities and Excess Molar Volumes of Monoalcohols + Water

The refractive index, n _D , and density, ρ, of binary mixtures of monoalcohols + water, have been measured at a temperature of 298.15,K and atmospheric pressure. The variation of the refractive indices of these solutions has also been determined with temperature in the range T = (278.15 to 338.15) K and atmospheric pressure. A comparative study has been made of the refractive indices obtained experimentally and those calculated by means of the Lorentz-Lorenz [Theory of Electrons, Dover Phoenix (1952)] and Gladstone-Dale relations [Trans. R. Soc. London 148:887–902 (1858)]; in all cases, the Gladstone–Dale equation was seen to afford values similar to those obtained experimentally. Calculations have been made of the excess molar volumes, V ^E, and the molar refraction deviations, ΔR, of these mixtures and the differences between the experimental values for refractive index and those obtained by means of the Gladstone–Dale equation. Values of V ^E were compared with others in the literature. In all cases the V ^E values were negative, and in all cases, except in the methanol + water, ΔR showed a maximum for x = 0.8.     

Dielectric properties of beryllia ceramics in the near-millimeter wavelength range

We report the refractive indices and absorption coefficients for four beryllia (BeO) ceramic samples. These dielectric properties have been measured over the range from 4 to 18 cm^–1 by use of a Michelson interferometer. The index n, follows the linear relationship n=0.6517 cm³/g×+0.7130 with density, , over the range 2.8<<3.0 g/cm³.     

Multifold curdlan gel formation by dialysis into aqueous solutions of metal salts

We have found that the dialysis of curdlan dissolved in alkaline solution into aqueous solutions of metal salts yielded multifold gel structures. Aqueous sodium chloride and potassium chloride as well as pure water induced isotropic gels. Aqueous calcium salts induced liquid crystalline gel with refractive index gradient/amorphous gel alternative structure. Aqueous salts of trivalent aluminum and ferric cations induced a rigid liquid crystalline gel, which shrank above a threshold concentration of each salt. On the other hand, Liesegang ring-like pattern was observed with aqueous solutions of mixed salts of calcium chloride and magnesium chloride. The patterns have been classified to discuss the mechanism of forming the variety of structures.     

分子拓扑指数在晶格能中的应用

分子拓扑指数在晶格能中的应用凌天才（重庆师范学院化学系重庆６３００４７）关键词拓扑指数，晶格能分子拓扑指数实际上是分子图的不变量。自ｗｉｅｎｅｒ￣［１］于１９４７年首次提出ｗｉｅｎｅｒ指数并用以关联烃类的沸点等数据以来，分子拓扑指数广泛用于关联与预测...     

Effect of the modification of silica on thermal properties and flammability of cross-linked butadiene-acrylonitrile rubbers

The paper presents the results of testing the thermal stability and flammability of butadiene-acrylonitrile rubber vulcanizates with different contents of combined acrylonitrile: Perbunan NT 1845 and Perbunan NT 3945 from Bayer, containing unmodified and bromine- or iodine-modified silica. The test results were obtained with the use of a derivatograph, measurements of flammability by the method of oxygen index, in air and also with the use of a cone calorimeter. The effect of the modification on the zeta potential was also examined. A considerable reduction in the flammability of nitrile rubber vulcanizates filled with silica can be obtained by the modification of filler with bromine or iodine. All the vulcanizates containing modified silica are self-extinguishing. An appropriate filling of NBR 39 vulcanizates with bromine-modified silica makes it possible to obtain non-flammable polymeric materials. They neither ignite nor glow under the action of a flame source for 30 s. The findings can be a rational basis for the synthesis of modified silica that can act as active filler and effective flame-retardant agent at the same time.     

Cumulative indices for Spectrochima Acta, Part A and Spectrochimica Acta, Part B

This article is an electronic publication in Spectrochimica Acta Electronica (SAE), a section of Spectrochimica Acta, Part B (SAB). The hardcopy text is accompanied by an electronic archive, stored on the SAE homepage at http://www.elsevier.nl/locate/sabe. The archive contains data, index and program files. The main article discusses the bibliographical purpose of the program and data files. A collective index for Spectrochimica Acta for volumes since it was split into Parts A and B, and continuing through 1991 for SAA and 1997 for SAB, is presented in DBF format, along with rudimentary data entry and access software.     

诱导效应指数与脂肪族胺、醇和醚的气相碱性

用烷基诱导效应指数I和RX分子中质子亲合原子X所带电荷qx及元素电负性XN与 脂肪胺，醇、醚的气相质子亲合PA进行关联，结果表明，脂肪胺，醇、醚的气相碱 性可以用下式定量描述：PA(kJ.mol^-1)-2732.0333-2457.1510∑I-1492.2351qx- 732.6277XN利用上式对64种化合物的气相碱性进行预测，平均相对误差为0．34％ ，预测值和实验值的偏差均在实验误差范围内。