A wave automaton for Maxwell's equations

This paper presents an extension to electromagnetic fields of the wave automaton, which was introduced in recent years for describing wave propagation in inhomogeneous media. Using elementary processes obeying a discrete Huygens' principle and satisfying fundamental symmetries such as time reversal and reciprocity, this new wave automaton is capable of modeling Maxwell's equations in 3+1 dimensions. It supplements the methods that were developed early for scalar and spinor fields. Received 19 July 2001     

Brute-force orientation of178m 2Hf and magnetic moments of178m 1Hf and178m 2Hf

Gamma-ray anisotropy measurements have been carried out with brute-force oriented^178m ₂Hf (16⁺) to derive its magnetic moment 7.26 (±0.16; +0.2/−0) nm and E2/M1 mixing ratios of some γ-transitions observed in the decay of this isomer. This magnetic moment is in agreement with an earlier proposed four-quasi-particle configuration. The magnetic moment of the 8⁻ isomer at 1147.7 keV (4.0 s) is estimated to be between 1.4 and 5.3 nm, which confirms mixing of the {p[514]9/2 +p[404]7/2}8⁻ and {n[514]7/2+n[624]9/2}8⁻ configurations, which summed together give the 16⁺ isomer.     

Maximum directed cuts in digraphs with degree restriction

For integers m, k≥1, we investigate the maximum size of a directed cut in directed graphs in which there are m edges and each vertex has either indegree at most k or outdegree at most k. © 2009 Wiley Periodicals, Inc. J Graph Theory     

Synthesis of novel alkylamino zinc(II) phthalocyanines

The synthesis of tetramethyl‐tetraphthalimidomethyl‐phthalocyaninato zinc(II) ( 6 ) and tetramethyl‐tetraaminomethyl‐phthalocyaninato zinc(II) ( 7 ) is described.     

In-beam orientation of low energy mass-separated radioactive beams: Development of the technique and first results

We report on the first results obtained with a system designed to polarize on-line mass-separated radioactive ion beams by scattering the beams from very flat single crystal surfaces at grazing incidence angles. Polarizations of 1 to 2% were already observed for deuterium.     

Crosslinking and ageing of C labelled polyisoprene part 1: Synthesis and polymerisation of 4-C-isoprene

4-¹³C-isoprene was prepared by the Wittig reaction. All reaction steps were optimised using unlabelled compounds. By reaction with triphenyl phosphine, ¹³C labelled methyl iodide afforded labelled methyl-triphenyl phosphine iodide in 84% yield. This reacted with meth acrolein with production of 4-¹³C-isoprene in 64% yield. Labelled polyisoprene was prepared by anionic polymerisation initiated by t-butyl lithium. Based on ¹³CH₃I the overall yield is ca 30%. The polymer was characterized by ¹H and ¹³C NMR spectroscopy. The contribution of each microstructure was [cis 1-4, 72%]; [trans 1-4, 10%]; [3-4, 18%].     

Electronic structure of paramagnetic clusters of transition metal ions. 3. Magnetic properties and scattered wave description of the electronic structure of the hexanuclear octahedral cluster [Fe6(μ3−S)8(PEt3)6] (BPh4)2

Spin-polarized Xα–SW calculations of [Fe₆(μ₃?S)₈(PH₃)₆]²⁺ as a model of the cluster [Fe₆(μ₃?S)₈(PEt₃)₆] (BPh₄)₂ have been performed. The highest occupied energy levels are well separated from empty levels, and up to a maximum of eight electrons can be unpaired, giving a maximum spin state with S = 4. This electronic state is consistent with the magnetic data of [Fe₆(μ₃?S)₈(PEt₃)₆](BPh ₄)₂, which have been interpreted using the Heisenberg–Dirac–Van Vleck exchange spin Hamiltonian. The S = 4 state arises from the magnetic coupling between five low-spin (S_i = 1/2) and one intermediate-spin (S = 3/2) iron(III) center. © 1994 John Wiley & Sons, Inc.     

Pyridazines 92. Synthesis of dialkyldipyridazinodiazepinones as potential HIV‐1 reverse transcriptase inhibitors

Two methods for the preparation of dialkylsubstituted dipyridazino[4,3‐b:3′,4′‐e][1,4]diazepinones and dipyridazino[3,4‐b:3′,4′‐e][1,4]diazepinones are reported. The new compounds were evaluated for their inhibitory effects against the replication of human immunodeficiency virus [HIV‐1(III_B) and HIV‐2(ROD)] in MT‐4 cells.