Observation of radiative B-->phi K gamma decays

The radiative decay B-->phi K gamma is observed for the first time. The branching fraction for the charged B--->phi K- gamma decay mode is measured to be B(B--->phi K- gamma)=(3.4+/-0.9+/-0.4)x10(-6). The photon energy distribution for the B--->phi K- gamma decay is presented. The signal for the neutral B(0)-->phi K(0)gamma decay mode is not statistically significant and an upper limit, B(B(0)-->phi K(0)gamma)<8.3x10(-6) at 90% C.L., is set. The analysis is based on a data set of 90 fb(-1) collected by the Belle experiment at the e(+)e(-) asymmetric collider KEKB.     

Measurement of branching fractions for B-->eta(c)K(*) decays

We report measurements of branching fractions for charged and neutral B-->eta(c)K decays where the eta(c) meson is reconstructed in the K(0)(S)K+/-pi(-/+), K+K-pi(0), K(*0)K-pi(+), and pp; decay channels. The neutral B0 channel is a CP eigenstate and can be used to measure the CP violation parameter sin(2phi(1). We also report the first observation of the B0-->eta(c)K(*0) mode. The results are based on an analysis of 29.1 fb(-1) of data collected by the Belle detector at KEKB.     

A generalization of gamma functions and Kronecker's limit formulas

We obtain a “Kronecker limit formula” for the Epstein zeta function. This is done by introducing a generalized gamma function attached to the Epstein zeta function. The methods involve generalizing ideas of Shintani and Stark. We first show that a generalized gamma function appears as the value at s=0 of the first derivative of the associated Epstein zeta function. Then this is used to yield Kronecker's limit formula and its “s=0”-version.     

Self-assembly formation of the ordered nanostructure arrays induced by Be interaction with Si(1 1 1) surface

Formation of the beryllium (Be) submonolayers on the Si(1 1 1)7 × 7 surface has been studied using scanning tunneling microscopy. It has been found that Be interaction with Si(1 1 1) at 500-700 °C results in a self-assembly formation of the four various types of the highly-ordered nanostructure arrays. The nanostructure arrays develop on top of the “soft” silicide layer, which period and orientation alter with the nanostructure growth: the shorter the nanostructure period, the larger the rotation angle. The main structural parameters of the silicide layer and nanostructure arrays have been established.     

Analysis of a time-limited service priority queueing system with exponential timer and server vacations

We consider a multi-class priority queueing system with a non-preemptive time-limited service controlled by an exponential timer and multiple (or single) vacations. By reducing the service discipline to the Bernoulli schedule, we obtain an expression for the Laplace-Stieltjes transform (LST) of the waiting time distribution via an iteration procedure, and a recursive scheme to calculate the first two moments. It is noted that we have to select embedded Markov points based on the service beginning epochs instead of the service completion epochs adopted for most of M/G/1 queueing analyses. Through the queue-length analysis, we obtain a decomposition form for the LST of the waiting time in each queue having the exhaustive service.      

Improvement of stability of phenacyloxycarbamidomethyl (Pocam) group,a cysteine protecting group removable with zinc reduction,under acidic conditions

In order to improve the stability of phenacyloxycarbamidomethyl (Pocam) group, a cysteine protecting group removable with zinc reduction, under acidic conditions, various alkyl substituents on the nitrogen atom of Pocam group were examined. As a result, attachment of an electron-withdrawing group improved the stability, and 2,2,2-trifluoroethyl (Tfe) group was most effective among four substituents tested. Tfe-Pocam group could be used in solid-phase peptide synthesis and peptide condensation reactions, and it was also useful for regioselective disulfide formation reactions.     

Coexistence of Two Thermally Induced Intramolecular Electron Transfer Processes in a Series of Metal Complexes [M(Cat‐N‐BQ)(Cat‐N‐SQ)]/[M(Cat‐N‐BQ)2] (M=Co,Fe, and Ni) bearing Non‐Innocent Catechol‐Based Ligands: A Combined Experimental and Theoretical Study

The different thermally induced intermolecular electron transfer (IET) processes that can take place in the series of complexes [M(Cat‐N‐BQ)(Cat‐N‐SQ)]/[M(Cat‐N‐BQ)₂], for which M=Co ( 2 ), Fe ( 3 ) and Ni( 4 ), and Cat‐N‐BQ and Cat‐N‐SQ denote the mononegative (Cat‐N‐BQ^?) or dinegative (Cat‐N‐SQ^2?) radical forms of the tridentate Schiff‐base ligand 3,5‐di‐tert‐butyl‐1,2‐quinone‐1‐(2‐hydroxy‐3,5‐di‐tert‐butylphenyl)imine, have been studied by variable‐temperature UV/Vis and NMR spectroscopies. Depending on the metal ion, rather different behaviors are observed. Complex 2 has been found to be one of the few examples so far reported to exhibit the coexistence of two thermally induced electron transfer processes, ligand‐to‐metal (IET^LM) and ligand‐to‐ligand (IET^LL). IET^LL was only found to take place in complex 3 , and no IET was observed for complex 4 . Such experimental studies have been combined with ab initio wavefunction‐based CASSCF/CASPT2 calculations. Such a strategy allows one to solicit selectively the speculated orbitals and to access the ground states and excited‐spin states, as well as charge‐transfer states giving additional information on the different IET processes.     

Pressure-induced structural transformations and the anomalous behavior of the viscosity in network chalcogenide and oxide melts

It is known that a number of compressed melts undergo structural phase transitions. Data on the structural changes at high pressures in chalcogenides (AsS, As₂S₃) and oxide (B₂O₃) melts with a network structure have been reviewed. Viscosity is one of the fundamental physical properties of a liquid. For various melts, it varies in a very wide range. Structural transformations in melts induce the corresponding changes in all physical properties, in particular viscosity. The measurements of the viscosity of a number of melts at high pressures and temperatures by the radiographic method have been reported. Changes in the viscosity by several orders of magnitude have been detected when the pressure is varied by several gigapascals. The diffusion mechanism in network-structure melts at various pressures has been analyzed. The prediction of the behavior of the viscosity of various melts at superhigh pressures is of high importance for the physics of glass transition, geophysics, and materials science.