Synthetic,spectral, thermal and antimicrobial studies of bis(N,N‐dialkyldithiocarbamato)arsenic(III) and antimony(III) complexes with diphenyldithiophos‐phate and diphenyldithiophosphinate

Bis(N,N‐dialkyldithiocarbamato)arsenic(III)/antimony(III) diphenyldithiophosphate/diphenyldi‐thiophosphinate complexes of the type [R₂NCS₂]₂MS(S)PX₂ [where M = As and Sb; NR₂ = N(CH₃)₂, N(C₂H₅)₂ and N(CH₂)₄; X = OC₆H₅ and C₆H₅] have been synthesized and characterized by physico‐chemical, spectral [UV, IR and NMR (¹H, ¹³C and ³¹P)] and thermal (TG, DTA and DSC) analysis. The TG analysis shows single‐step decomposition of the complex to Sb₂S₃. These complexes have been screened for antibacterial and antifungal activity using the disc diffusion method. All the complexes have shown good activity as antibacterial and antifungal agents, which increased on increasing the concentration. Chloroamphenicol and terbinafin were used as standards for the comparison. Copyright © 2006 John Wiley & Sons, Ltd.     

Freezing transition in the Ising model without internal contours

We consider the low temperature Ising model in a uniform magnetic field h > 0 with minus boundary conditions and conditioned on having no internal contours. This simple contour model defines a non-Gibbsian spin state. For large enough magnetic fields (h >: h _c ) this state is concentrated on the single spin configuration of all spins up. For smaller values (h≤h _c ), the spin state is non-trivial. At the critical point h _c ≠ 0 the magnetization jumps discontinuously. Freezing provides also an example of a translation invariant weakly Gibbsian state which is not almost Gibbsian. Received: 10 November 1998     

One-point extensions of Markov processes by darning

This paper is a continuation of the works by Fukushima–Tanaka (Ann Inst Henri Poincaré Probab Stat 41: 419–459, 2005) and Chen–Fukushima–Ying (Stochastic Analysis and Application, p.153–196. The Abel Symposium, Springer, Heidelberg) on the study of one-point extendability of a pair of standard Markov processes in weak duality. In this paper, general conditions to ensure such an extension are given. In the symmetric case, characterizations of the one-point extensions are given in terms of their Dirichlet forms and in terms of their L ²-infinitesimal generators. In particular, a generalized notion of flux is introduced and is used to characterize functions in the domain of the L ²-infinitesimal generator of the extended process. An important role in our investigation is played by the α-order approaching probability u _α . The research of Z.-Q. Chen is supported in part by NSF Grant DMS-0600206. The research of M. Fukushima is supported in part by Grant-in-Aid for Scientific Research of MEXT No.19540125.     

Zero Distribution of Bergman Orthogonal Polynomials for Certain Planar Domains

   Abstract. Let G be a simply connected domain in the complex plane bounded by a closed Jordan curve L and let P _n , n≥ 0 , be polynomials of respective degrees n=0,1,··· that are orthonormal in G with respect to the area measure (the so-called Bergman polynomials). Let ϕ be a conformal map of G onto the unit disk. We characterize, in terms of the asymptotic behavior of the zeros of P _n 's, the case when ϕ has a singularity on L . To investigate the opposite case we consider a special class of lens-shaped domains G that are bounded by two orthogonal circular arcs. Utilizing the theory of logarithmic potentials with external fields, we show that the limiting distribution of the zeros of the P _n 's for such lens domains is supported on a Jordan arc joining the two vertices of G . We determine this arc along with the distribution function.     

Hölder estimates of p-harmonic extension operators

It is now a well-known fact that for 1<p<∞ the p-harmonic functions on domains in metric measure spaces equipped with a doubling measure supporting a (1,p)-Poincaré inequality are locally Hölder continuous. In this note we provide a characterization of domains in such metric spaces for which p-harmonic extensions of Hölder continuous boundary data are globally Hölder continuous. We also provide a link between this regularity property of the domain and the uniform p-fatness of the complement of the domain.     

Direct detection of alkylphosphonic acids in environmental matrices by proton coupled phosphorus NMR

A simple, convenient, and direct one‐dimensional (1D) ³¹P NMR technique is demonstrated for the detection of alkylphosphonic acids (marker of nerve agents). The results of detection were validated after conducting various in‐house exercises. The confidence generated by this study was found very useful in detection of different alkylphosphonic acids spiked in various official interlaboratory proficiency tests conducted by Organisation for the Prohibition of Chemical Weapons (OPCW). Copyright © 2009 John Wiley & Sons, Ltd.     

Quantum-chemical Study of the Structure of 1,2,2,3,4,4-Hexachloro-1,3-diphosphetane Isomers

We have used the RHF/6-31G* method to optimize the geometric parameters of three isomers of the (ClP–CCl₂)₂ molecule. We have established that the trans isomer is the most stable, and that it is energetically more favorable than the two cis isomers by 7.8 and 14.2 kJ/mole respectively.