On the equivalence of theKMS condition and the variational principle for quantum lattice systems

For quantum spin systems on a lattice of an arbitrary dimension, theKMS condition and the variational principle are shown to be equivalent at an arbitrary temperature for translationally invariant states.     

Beam-size measurement with optical diffraction radiation at KEK accelerator test facility

An experiment on the investigation of optical diffraction radiation (ODR) from a slit target as a possible tool for noninvasive electron beam-size diagnostics has been performed at the KEK accelerator test facility. The experimental setup has been installed at the diagnostics section of the extraction line. We have performed the first incoherent ODR observation from a slit target. The measured angular distributions are in reasonable agreement with the theoretical expectation. The beam-size effect onto the ODR angular pattern has been observed. Moreover, the sensitivity to the beam size as small as 14 microm has been achieved.     

Chiral phosphinooxazolidine ligands for palladium- and platinum-catalyzed asymmetric Diels-Alder reactions

Cationic palladium (Pd)- and platinum (Pt)-phosphinooxazolidine catalysts 13a-c, 15a-d, 17a-c, and 19a-c were prepared from phosphinooxazolidine ligands 1-3, MCl(2) (M = Pd and Pt), and counterions, and the activities of the catalysts in the asymmetric Diels-Alder (DA) reactions of cyclic or acyclic dienes with imide dienophiles were investigated. These catalysts demonstrated high levels of catalytic activity. The cationic Pd-POZ complex 13c provided particularly excellent enantioselectivity (98% ee) in the DA reactions of cyclopentadiene with acryloyl-, crotonyl-, and fumaroyl-1,3-oxazolidin-2-ones (20a-c).     

Rotating superfluid turbulence

Almost all studies of vortex states in helium II have been concerned with either ordered vortex arrays or disordered vortex tangles. This work numerically studies what happens in the presence of both rotation (which induces order) and thermal counterflow (which induces disorder). We find a new statistically steady state in which the vortex tangle is polarized along the rotational axis. Our results are used to interpret an instability that was discovered experimentally by Swanson et al. [Phys. Rev. Lett. 50, 190 (1983)]] and the vortex state beyond the instability that has been unexplained until now.     

Fabrication and observation of nanowire-assemblages of Si-Ge

A few of the interesting structures made by the assemblage of Si-Ge nanowires fabricated by the floating-zone melting-vapor method have been observed. They reveal shapes that are similar to coral, jellyfish and sea anemones. The pre-sintered substrate bar has some large crystalline particles (1–15 μm), which produce sites that are energetically predisposed to nucleation. The peculiar structures created by the assemblage of Si-Ge nanowires form on favored nucleation sites that consist of numerous bundles of nanowires with diameters of 20–50 nm. The periodic variation in the diameter of the bundles of nanowires is a common feature of these structures. In addition, a growth mechanism assisted by the coexistence of Ge and Si-Ge oxides is suggested. The growth process of these assemblages opens up new possibilities for the study of the growth mechanism of Si-Ge nanowires. Received: 25 July 2002 / Accepted: 9 September 2002 / Published online: 17 December 2002 RID="*" ID="*"Corresponding author. Fax: 81-298/59-2736, E-mail: HU.Quanli@nims.go.jp     

Enantioselective synthesis of attenols A and B

[reaction: see text] Enantioselective synthesis of attenols A and B was accomplished by using diastereoselective hydroboration, Lindlar reduction, and acid-catalyzed acetal formation.     

A New Preparative Method for Allylic Indium(III) Reagents by Reductive Transmetalation of pi-Allylpalladium(II) with Indium(I) Salts

A reductive transmetalation of the pi-allylpalladium(II) complexes, generated in situ from a catalytic amount of a palladium(0) complex and a variety of allylic substrates, with indium(I) salts proceeded smoothly in various solvents, providing a new route for allylindium(III) reagents.