Ward Takahashi identities and fluctuation-dissipation theorem in a superspace formulation of the Langevin equation

A class of Langevin equations is formulated as a field theory in superspace. The Ward Takahashi identities associated with the hidden supersymmetry are derived which in turn are shown to lead to the fluctuation dissipation theorems.     

Coordination compounds of Cu(II), Ni(II) and Co(II) with sulphamethazine-5-bromo-salicylaldimine

Coordination compounds of Cu (II), Ni (II) and Co (II) with sulphamethazine salicylaldimine (an antitubercular) have been prepared with a view to study their antibacterial activity. These complexes are granular, stable and are quantitatively formed and characterised by elemental analysis. Structures have been assigned based on their infrared, electronic absorption spectral and magnetic susceptibility studies. The antibacterial activity was tested against eleven available pathogens and in some cases complexes are found to be more potent.     

Dilute-solution properties of trans-1,4-polyisoprene

Trans-1,4-polyisoprene was fractionated by both fractional precipitation and preparative gel permeation chromatography to obtain possibly sharp fractions of narrow molecular weight distribution. Selected fractions were characterized by light scattering, viscosity, and gel permeation chromatography. Necessary corrections for molecular heterogeneity were applied. Some of the characteristic relations between [η] and M _w are [η] = 1.81 × 10^?4 M in benzene at 30°C, [η] = 1.38 × 10^?4 M in n-hexane at 30°C, which are found to be in good agreement with literature data when corrected for molecular heterogeneity.     

Generalized diffusion and quasi-elastic scattering widths in two-dimensional systems

The paper presents approximate calculations of dimensionality and lattice symmetry effects in the wave vector and frequency dependent diffusional response of disordered lattices. Numerical results are given and comparatively discussed for the tracer diffusion correlation function and the quasi-elastic incoherent scattering width in triangular, simple square and simple cubic lattices, only the restriction of double occupancy avoidance being taken into account. The quasi-elastic coherent scattering width is estimated for a triangular system possessing liquid-like structural disorder by means of the simple inclusion of a spread in jump lengths around a preferred set of jumps. Qualitative contact is made with recent neutron scattering experiments on alkali-metal graphite intercalation compounds.     

Exact Fokker-Planck equations from stochastic master equations

A method for deriving exact Fokker-Planck equations from stochastic master equations by expanding the probability distribution in terms of Poisson distribution is given. It is applied to two non-linear chemical processes to obtain the steady state distributions.     

Ionic correlations in fused salts

The expression for the fourth frequency moment of current correlation function in a two-component fluid is derived. This result is used to obtain certain exact sum rules, in the long-wavelength limit, for charge current correlations in fused salts.     

Potentiometrische Untersuchungen an ternären Komplexen Eisen(III)-Nitrilotriessigsäure-zweizähnige Liganden

The evidences for the formation of 1 : 1 : 1 ternary complexes in the system, Fe(III)-nitrilotriacetic acid-bidentate ligand (where bidentate ligands: oxalic acid, tiron, chromotropic acid, 8-hydroxyquinoline-5-sulphonic acid) have been cited on the basis of potentiometric studies. The hydrolytic behaviour of these biligand species has also been discussed.

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Mit 2 Abbildungen     

An Efficient, One-Pot, Triton-B Catalyzed Synthesis of O-Alkyl-S-methyl Dithiocarbonates

Summary. A novel process for the one-step conversion of a variety of primary and secondary alcohols into their O-alkyl-S-methyl dithiocarbonates using methyl iodide catalyzed by the Triton-B/CS₂ system was developed. Thus, O-alkyl-S-methyl dithiocarbonates were obtained in very good to excellent yields. This protocol is mild and efficient compared to other methods.