Cross sections for multi-particle final states at a linear collider

In this paper total cross sections for signals and backgrounds of top- and Higgs-production channels in e ⁺ e^- collisions at a future linear collider are presented. All channels considered are characterized by the emergence of six-particle final states. The calculation takes into account the full set of tree-level amplitudes in each process. Two multi-purpose parton level generators, HELAC/PHEGAS and AMEGIC + + , are used, and their results are found to be in perfect agreement.Received: 26 November 2003, Revised: 15 January 2004, Published online: 3 March 2004     

Relativistic effective potential SCF calculations of AgH and AuH

Relativistic effective potentials (REP) are now widely used in molecular electronic structure calculations. Tests of these REP are needed to assess their accuracy. This can now be done for AgH and AuH since Lee and McLean have published Dirac-Fock calculations for these molecules. Comparative SCF calculations have been performed for two types of effective potential. Satisfactory agreement between the effective potential results and Dirac-Fock values is found for spectroscopic constants and dipole moments, which supports the use of these potentials for heavy atom containing molecules.     

Heat conduction, convection and radiolysis of the

Metabolites from Microorganisms, 6-Chlorogenistein and 6,3′-Dichlorogenistein A strain of Streptomyces griseus produced chlorinated metabolites in media containing soybean meal. Two of these metabolites were isolated together with a chlorine free compound which could be identified as the isoflavone genistein (I) by its spectral properties and by comparison with an authentic sample. By NMR. and mass spectroscopy the chlorinated compounds were shown to be 6-chlorogenistein (II) and 6,3′-dichlorogenistein (III). The 7-glucoside of genistein is a constituent of soybean meal; it is hydrolysed and chlorinated by Streptomyces griseus.     

Stoffwechselprodukte von Mikroorganismen 6-Chlorgenistein und 6,3′-Dichlorgenistein. 164. Mitteilung

Metabolites from Microorganisms, 6-Chlorogenistein and 6,3′-Dichlorogenistein A strain of Streptomyces griseus produced chlorinated metabolites in media containing soybean meal. Two of these metabolites were isolated together with a chlorine free compound which could be identified as the isoflavone genistein (I) by its spectral properties and by comparison with an authentic sample. By NMR. and mass spectroscopy the chlorinated compounds were shown to be 6-chlorogenistein (II) and 6,3′-dichlorogenistein (III). The 7-glucoside of genistein is a constituent of soybean meal; it is hydrolysed and chlorinated by Streptomyces griseus.     

Dynamics of proton transfer in bacteriorhodopsin

Proton transfer in bacteriorhodopsin from the cytoplasm to the extracellular side is initiated from protonated asp96 in the cytoplasmic region toward the deprotonated Schiff base. This occurs in the transition from the photocycle late M state to the N state. To investigate this proton-transfer process, a quantum mechanics/molecular mechanics (QM/MM) model is constructed from the bacteriorhodopsin E204Q mutant crystal structure. Three residues, asp96, asp85, and thr89, as well as most of the retinal chromophore and the Schiff base link of lys216 are treated quantum mechanically and connected to the remaining classical protein through linker atom hydrogens. Structural transformation in the M state results in the formation of a water channel between the Schiff base and asp96. Since a part of this channel is lined with hydrophobic residues, there has been a question on the mechanism of proton transfer in a hydrophobic channel. Ab initio dynamics using the CHARMM/GAMESS methodology is used to simulate the transfer of the proton through a partially hydrophobic channel. Once sufficient water molecules are added to the channel to allow the formation of a single chain of waters from asp96 to the Schiff base, the transfer occurs as a fast (less than a picosecond) concerted event irrespective of the protonation state of asp85. Dynamic transfer of the proton from asp96 to the nearest water initiates the organization of a strongly bonded water chain conducive to the transfer of the proton to the Schiff base nitrogen.     

Quantum hair and quantum gravity

A black hole may carry quantum numbers that arenot associated with massless gauge fields, contrary to the spirit of the no-hair theorems. The quantum hair is invisible in the classical limit, but measurable via quantum interference experiments. Quantum hair alters the temperature of the radiation emitted by a black hole. It also induces non-zero expectation values for fields outside the event horizon; these expectation values are non-perturbative in , and decay exponentially far from the hole. The existence of quantum hair demonstrates that a black hole can have an intricate quantum-mechanical structure that is completely missed by standard semiclassical theory.Based on an essay which received second award from the Gravity Research Foundation, 1991     

Oberflächenverbindungen von Übergangsmetallen. XXIX. Die Umsetzung von Oberflächen-Chrom(VI)/Silicagel mit Aluminiumalkylen: „Formierte”︁ Phillips-Katalysatoren

Surface Compounds of Transition Metals. XXIX. Reaction of Surface Chromium (VI)/Silica Gel with Aluminium Alkyles: “Formation” of Phillips Catalysts By the reaction of surface chromium (VI)/silicagel with aluminium alkyles - leading to the so called “Phillips catalysts fo the second generation” - the metal is reduced in two 2e steps via a chromium (IV) intermediate to a final Cr product. The extent of the reduction depends on the ratio Al/Cr, the influence fo light, the presence of higher olefins and the temperature.