About 3D solution of diffraction problems by MMDS

A new universal 3D scalar and vector modification to the method of discrete sources (MMDS) for the numerical calculation of the scattering pattern of the body of revolution is described. To illustrate the use of the developed technique, the scattered field of the spheroid and multifoil of revolution are calculated. It is shown that analytical transformation of the scatterer's surface and wavelet technique allows creating an efficiency algorithm with rather small time of computation.     

H2: An Archetypal Molecule or an Odd Exception?

Structural Chemistry -     

Mathematical model of calibration curve and results of spectral analysis

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 51, No. 5, pp. 805–810, November, 1989.     

A New Theoretical Modeling of Surface Resistance in Normal Metals at Terahertz Frequencies

A number of researchers have reported discrepancies between surface resistance measurements and classical theoretical predictions for simple mm-wave and sub-mm-wave structures. We have developed a rigorous phenomenological model for analyzing surface resistance of normal metals. The model is based on quantum mechanical analysis for spatial dispersion within the metal. We have used the model to predict the surface resistance in normal metals at terahertz frequencies. Our analysis shows that the conductivity is not only frequency but also wave vector dependent. Moreover, we have compared the results of this model with the results of the classical skin-effect model and classical relaxation- effect model. We demonstrate that our model has good quantitative agreement with the published experimental data for the room temperature surface resistance of normal metals at terahertz frequencies range from the literature.     

Structure of Dibenzocrown Ethers and their H-Bonded Adducts. 2. Structure Peculiarities of Supramolecular Assemblages Formed by [1.5]Dibenzo-18-Crown-6 and Some NH-Donors

[1.5]Dibenzo-18-crown-6 ([1.5]DB18C6) forms the H-bonded supramolecular complexes with 3-nitro-1H-1,2,4-triazole (1:1), 2,4(1H,3H)-pyrimidinedithione (1:1), 1,2,5-oxadiazole-3,4-diamine monohydrate (1:1:1), ethanedithioamide (1:1) and 1,2-hydrazinedicarbothioamide (2:3). The first two complexes are discrete molecular adducts, two next complexes represent different types of tapes, while in the last complex the components are linked into 3D grid. In all cases, the formation of co-crystals results in the substitution of all or part of supramolecular homosynthons by heterosynthons and in the changing of supramolecular architecture.This revised version was published online in July 2005 with a corrected issue number.     

Method for performing a single act of the reversible separation of ideal solution components

Russian Journal of Physical Chemistry A - A method for performing a single act of separation of the components contained in a liquid solution of optical isomers in a reversible process is proposed....     

Mannanase Transfer into Hexane and Xylene by Liquid–Liquid Extraction

The formation of noncovalent complexes between glycosidase, endo-1,4-β-d-mannanase, and ionic surfactant di(2-ethylhexyl) sodium sulfosuccinate (AOT) was shown to promote protein transfer into organic solvents such as xylene and hexane. It was found that mannanase can be solubilized in hexane and in xylene with concentration at least 2.5 and 2.0 mg/ml, respectively. The catalytic activity of the enzyme in hexane spontaneously increases with the concentration of AOT and is about 10% of the activity in aqueous system. In xylene, a catalytic activity higher than that in bulk aqueous conditions was found for the samples containing 0.1–0.3 mg/ml of mannanase, while for the samples with a higher concentration of enzyme, the activity was hardly detected.