Universal fermi gas with two- and three-body resonances

We consider a Fermi gas with two components of different masses, with the s-wave two-body interaction tuned to unitarity. In the range of mass ratio 8.62相似文献   

Spin dynamics in iron-based layered superconductor (La0.87Ca0.13)FePO revealed by 31P and 139La NMR studies

We report 31P and 139La NMR studies of (La0.87Ca0.13)FePO, which is a family member of the recently discovered superconductor LaFeAs(O1-xFx). In the normal state, Knight shift and nuclear spin-lattice relaxation rate divided by T (1/T1T) show that a Fermi-liquid state with moderate ferromagnetic fluctuations emerges below 30 K. From 1/T1T of 31P and 139La, a quasi-two- dimensional electronic structure is suggested, in which the FeP layer is more conductive than the LaO layer. In the superconducting (SC) state, although a clear Meissner signal was observed, 1/T1T increases below Tc, in contrast to a decrease of 1/T1T due to the opening of a SC gap, suggesting that novel low-energy spin dynamics develop in the SC state.     

A measurement method of the magnetic properties of magnetic sheet by means of a single sheet tester at audio frequency

A single sheet tester (SST) for audio frequency of 400 Hz–10 kHz was made experimentally and the magnetizing winding can get the nearly uniform distribution of flux density of a specimen in the longitudinal direction at the frequency up to 10 kHz. The flux densities at various positions of strips measured by the Epstein method were detected by search coils wound on strips at 400 Hz and 1.0 T. They have large discrepancy. However, the magnetic properties obtained from both methods have a little discrepancy. Although the uniformity of flux distribution in the Epstein frame is not sufficient, the average is fairly effective because the magnetic properties can be assumed to be locally linear within the small deviation of flux density.     

Interpretation of apparent chemical shifts in XP spectra from oxide—GaP interfaces

The cause of the apparent chemical shifts (ACS's) of XPS peaks between oxide and substrate GaP has been studied. The ACS's for Ga 3d, P 2p and GaLMM change significantly depending on the conditions of oxidation. The changes in the ACS's are considered in terms of not only the chemical structure of the oxide, but also other possible causes, such as charging effects, electric dipole moment, extra-atomic relaxation energy, Fermi-level pinning position, etc. The change of the Fermi-level position at the surface of substrate GaP is revealed to be a dominant factor causing the changes in the ACS's.     

Novel [D-Arg2]dermorphin(1-4) analogs with mu-opioid receptor antagonist activity

Ten Tyr-D-Arg-Phe-betaAla-NH(2) (YRFB) analogs in which specific amino acid side chains are shifted to the N(alpha)-position were synthesized, and the binding to these analogs to the mu receptor and their in vitro biological properties were evaluated. Some analogs in which a N,N-bis(p-hydroxybenzyl)-Gly residue was substituted for Tyr(1) exhibited mu receptor antagonist activities (pA(2)) between 5.3 and 6.1. Of these analogs, [N,N-bis(p-hydroxybenzyl)-Gly(1)]YRFB was found to be the most potent specific antagonist for the mu-opioid receptor.     

Enzymatic formation of an unnatural C(6)-C(5) aromatic polyketide by plant type III polyketide synthases

[reaction: see text] Substrate specificities of plant polyketide synthases (PKSs) were investigated using analogues of malonyl-CoA, the extension unit of the polyketide chain elongation reactions. When incubated with methylmalonyl-CoA and 4-coumaroyl-CoA, plant PKSs (chalcone synthase from Scutellaria baicalensis, stilbene synthase from Arachis hypogaea, and benzalacetone synthase from Rheum palmatum) afforded an unnatural C(6)-C(5) aromatic polyketide, 1-(4-hydroxyphenyl)pent-1-en-3-one, formed by one-step decarboxylative condensation of the two substrates. In contrast, succinyl-CoA was not accepted as a substrate by the enzymes.     

C2-symmetric bicyclo[2.2.2]octadienes as chiral ligands: their high performance in rhodium-catalyzed asymmetric arylation of N-tosylarylimines

Asymmetric synthesis of diarylmethylamines with high enantioselectivity (95-99% ee) was realized by use of a new C2-symmetric diene ligand, (1R,4R)-2,5-diphenylbicyclo[2.2.2]octa-2,5-diene (Ph-bod*), for the rhodium-catalyzed asymmetric arylation of N-tosylarylimines with arylboroxines.     

Higher homotopy commutativity of -spaces and the permuto-associahedra

In this paper, we give a combinatorial definition of a higher homotopy commutativity of the multiplication for an -space. To give the definition, we use polyhedra called the permuto-associahedra which are constructed by Kapranov. We also show that if a connected -space has the finitely generated mod cohomology for a prime and the multiplication of it is homotopy commutative of the -th order, then it has the mod homotopy type of a finite product of Eilenberg-Mac Lane spaces s, s and s for .

     

Analysis of spurious bulk waves in ball surface wave device

We analyzed the acoustic waves propagating in a sphere to establish a useful guideline for the design of NDE apparatus and ball surface acoustic wave (SAW) device exploiting the diffraction-free propagation of SAW on a sphere. First, we calculated the laser-generated acoustic displacements both under ablation condition and under thermoelastic condition and verified experimentally the validity of the calculation. Next, the acoustic waves excited by out-of-plane stress and those excited by in-plane stress were compared. The results showed that when the out-of-plane stress was applied, the relative amplitudes of the bulk waves to that of the SAW were larger and the number of bulk waves was larger than that when the in-plane stress was applied, while the SAW had similar waveforms in each case. The ratio of the relative amplitude of the bulk waves for the out-of-plane stress and the in-plane stress was 3.1:1 at phi(1)=90 degrees and 1.67:1 at phi(1)=0 degrees. The large amplitude for the out-of-plane stress can be explained by wide directivities of bulk waves. Consequently, we found that it is necessary for ball SAW device to select a piezoelectric material and form of interdigital transducer so that the in-plane stress becomes dominant.