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The compounds InMO[SUB4] (M=V, Nb, Ta) and BiVO[SUB4] are promising photocatalysts which are able to induce hydrolysis of water molecules under visible light irradiation. By first principles calculations, supported by experiments, we inspect their peculiar electronic structure in an attempt to rationalize the link between the bulk crystal architecture of the materiais and the related electronic properties. We find that the bottom of the conduction band of InMO[SUB4] systems consists of a large contribution (about 20%) due to 5s orbitals of In atoms. Another dominant component comes from d orbitals of V, Nb, and Ta. On the other hand, the top of the valence band of the BiVO[SUB4] shows a contribution from 6s orbitals of Bi of about 18% as well as a dominant component due to 2p states of O. We can infer that the photocatalytic activity could be improved by the large mobility coming from the s orbital component as well as by tuning the electron affinity (position of the bottom of the conduction band) and ionization potential (top of the valence band). The absorption process of a H[SUB2]O molecule in the In VO[SUB4] system was studied by fully relaxing the structure via first principles calculations. Our simulations have shown that the lone pairs of the O atom belonging to the H[SUB2]O molecule have a strong tendency to bind to In, while, at the same time, at least one of the H atoms of the water molecule forms a hydrogen bond with the O of the InVO[SUB4] catalyst surface. When a water molecule absorption occurs, it induces a shortening of the In-In and In-V bond lengths around ar the surface layer. This might suggest that the electron mobility is locally enhanced due to the resulting larger orbital overlap of In_5s-In_5s and In_5s-V_3d with respect to the case of absence of water. [ABSTRACT FROM AUTHOR]

A 1/2 magnetization plateau in magnetic fields above 23 T and antiferromagnetic (AF) long-range order (AFLRO) in low fields were observed in Cu2CdB2O6. Experimental results are consistent with quantum Monte Carlo results for an expected spin system. Two kinds of Cu sites [Cu(1) and Cu(2)] are located adjacent to each other. Spins on the Cu(1) sites are in a nearly spin-singlet state and a finite energy is necessary to break the nearly spin-singlet state. Spins on the Cu(2) sites are almost polarized in the 1/2 plateau region, whereas they form AFLRO in low fields. Therefore, the nearly spin-singlet state and AFLRO coexist adjacently in low fields, but exchange interaction between the Cu(1) and Cu(2) spins is not negligible. [ABSTRACT FROM AUTHOR]

The magnetic properties of Mn- and Eu-doped ZnS nanocrystals have been investigated. The results suggest that most of the Mn ions are coordinated on the surface of the nanocrystal, and the amount of Mn doped inside the nanocrystal does not exceed one per nanocrystal. Low-temperature magnetization shows the absence of antiferromagnetic interaction between Mn ions, in contrast to the bulk materials. For Eu-doped nanocrystal, the magnetic susceptibility data reveal the coexistence of Eu[SUP2+]and Eu[SUP3+]ions, though the starting material contains only Eu[SUP3+]ions. [ABSTRACT FROM AUTHOR]

Reports on the measurement of the high field magnetization in Sm[sub2]Fe[sub17]N[sub3.0]. Data on the observed magnetization curves; Calculation of the angle between the samarium moment and c axis.

Presents a study that measured the upper critical field hydrogen (H)[subc2] of superconducting niobium[sub3]germanium films prepared by sputtering and chemical vapor deposition in a pulsed field. Relation of the H[subc2] of the films to their superconducting critical temperature; Linear increase of H[subc2] in sputtered films; Dependence of H[subc2] to temperature.

Anodic porous alumina with duplex layers exhibits a voltage-induced switching effect and is a promising candidate for resistive random access memory. The nanostructural analysis of porous alumina is important for understanding the switching effect. We investigated the difference between the two layers of an anodic porous alumina film using transmission electron microscopy and electron energy-loss spectroscopy. Diffraction patterns showed that both layers are amorphous, and the electron energy-loss spectroscopy indicated that the inner layer contains less oxygen than the outer layer. We speculate that the conduction paths are mostly located in the oxygen-depleted area. [ABSTRACT FROM AUTHOR]

The article discusses the influence of defects on the propagation light within polymeric optical waveguides. The researchers have developed a polarization-preserving near-field scanning optical microscopy optical fiber probe, and with it observed the influence of defects and weak stresses on a propagation light within polymeric optical waveguides.

A new 52-mm warm-bore resistive insert for a hybrid magnet was designed and constructed at the Tsukuba Magnet Laboratory (TML) of the National Institute for Materials Science (NIMS). This magnet successfully generated a peak magnetic flux density of 35.5 T at the operating current of 34.88 kA and 367.5 V with a background field of 14.05 T. To supply the high magnetic fields for more time in the 52-mm warm bore, an axially cooled three-coaxial-coil structure and a staggered layout of the elongated cooling holes were adopted for Bitter disks after a parameter survey that was conducted to consider a reduction in the operating electric power. Disks were stacked in a modified Weggel scheme on a turntable with a rotating angle controlled by the stacking data of each coil. The innermost coil was connected electrically in series with the two outer coils connected in parallel. The Bitter disks used in the coils were made from two kinds of Cu-Ag plates. The magnet is now in operation for users. [ABSTRACT FROM AUTHOR]

The water-cooled insert magnet of the TML hybrid magnet successfully generated 37.9 T in a 32-mm room- temperature bore with a 14.02 T buckup field generated by a superconducting outsert magnet. At that magnetic field, the maximum electric power for the insert magnet was 13.35 MW. This Bitter-type insert magnet is divided into three coaxial coils, and the innermost coil consists of two coaxial coils. The inner coil is connected in series with the outer two coils connected in parallel. The Bitter plates for the outermost coil were made of GlidCop AL-25, and those for the other coils were made of hard-worked Cu-Ag plates. The thickness of the Cu-Ag plates was 0.40 mm, and the average 0.2 % yield strength was about 810 MPa at 373 K. [ABSTRACT FROM AUTHOR]

The performance of a flux concentrator using an YBCO oxide superconductor was tested to raise the steady state magnetic field generated by the existing magnet. This concentrator was composed of an outside hollow cylinder and a pair of half cylinders that goes in and out in the outside cylinder. This flux concentrator generated additional magnetic field more than 1.6 T for an applied magnetic field 28 T. [ABSTRACT FROM AUTHOR]

We have been developing an optical pumping nuclear spin polarizer (OPNSP) to enhance nuclear magnetic resonance (NMR) signals from small amount of nano- and biological materials. In this scheme, a semiconductor and a target (nano- or biological) material are in close contact with each other, and high nuclear spin polarization in the semiconductor created by the optical pumping method is transferred to the nuclei in the target material by a cross-polarization at the interfaces and a spin diffusion inside the target material. As a result, high nuclear spin polarization is realized in the target material. In this paper, we present profiles of the nuclear spin polarization in the target material of the OPNSP calculated for the multilayered and multi-columnar configurations, from which suitable designs of the OPNSP to achieve high nuclear polarization in the target materials are discussed. [ABSTRACT FROM AUTHOR]

The photo-induced hydrogen abstraction reactions of benzophenone in aqueous micellar SDS and Brij 35 solutions, decafluorobenzophenone in an aqueous micellar Brij 35 solution and naphthoquinone in an aqueous micellar SDS solution were investigated at room temperature under pulsed magnetic fields of 0-29.6 T. In each of these reactions, the radical pair decay rate is found to decrease with increasing field from 0 to about 3 T and to increase with increasing field above 3 T. The escape radical yield is found to increase with increasing field from 0 to about 3 T and to decrease with increasing field above 3 T. These magnetic field effects are explained in terms of the relaxation mechanism. In each of the Brij 35 micellar solution systems, the anisotropy in the g tensor of the ketyl radical and its correlation time are evaluated from the observed effects. [ABSTRACT FROM AUTHOR]

Electronic and atomic structures associated with a vacancy-type oxygen deficiency in an amorphous alumina model are studied by first-principles calculations. The energy levels of the oxygen defects significantly shift depending on their charge states because of remarkable changes of local atomic structures. That is different in character from the α crystal case. We discuss a possibility of the oxygen defects as a conductive path and present an atomistic mechanism of the resistive switching effects in the memory devices. [ABSTRACT FROM AUTHOR]

As a next-generation memory, we have developed a rare-metal-free memory using Al oxide with a high-density of oxygen vacancies (Vos). The electronic structure has been simulated using first-principles calculations. In this paper, we report the electronic structure of the band gap, analyzed using thermally stimulated current measurements, to evaluate the simulated results. We observed electronic states corresponding to resistance changes for the first time. These results show that Vo+2 (electron empty Vo) changes to Vo+1 by electron injection; the overlapped Vo+1 electron changes into a 'Vo conduction band' (VoCB), and the changed structure is stabilized by structural relaxation of Al ions around Vo. VoCB is considered as a kind of mid-gap impurity band. The origin of the on/off switching is considered to be generation/degeneration of the VoCB caused by increasing/decreasing numbers of Vo electrons. Based on knowledge of the electronic mechanism, we have changed metal/insulator/metal structure to a metal/insulator/semiconductor structure and decreased the reset-current to 7 μA. The Vos of Al oxide are considered to be useful for electronic memory storage. [ABSTRACT FROM AUTHOR]

Magnetic field effects on the triplet sensitization reaction of p-aminophenyl disulfide were studied in a sodium dodecylsulfate micellar solution by a nanosecond laser flash photolysis technique under ultrahigh magnetic fields of up to 28T. The yield of the escaped p-aminophenyl thiyl radical decreased by 6 ± 2% at 28T compared with that at 0T. [ABSTRACT FROM AUTHOR]

A local structure analysis using 27Al multiple-quantum magic-angle-spinning (MQMAS) and MAS NMR techniques has been performed on porous alumina fabricated by the anodic oxidation of aluminum. It is suggested that the main constituents of the inner and outer oxide layers composing porous alumina are [AlO4 and AlO5] and [AlO6], respectively, and that both of the layers adopt the amorphous structure. [ABSTRACT FROM AUTHOR]

We performed studies of the self-organization processes in nanoporous alumina membranes at initial and late stages of aluminum anodization by using scanning electron microscopy (SEM) and small-angle neutron scattering (SANS). SEM observations indicated three stages in the self-organization of nanopores in alumina: (1) nucleation of random nanopores with a broad radius distribution, (2) narrowing the radius distribution and (3) slow evolution of the nanoporous structure towards ordering of nanopores into large domains. SANS studies revealed orientational correlation between ordered domains of nanopores, which is characterized by a small misorientation angle. For the samples with high aspect ratios of nanopores, the SANS patterns showed azimuthal smearing, which was attributed to the redistribution of nanopores between the domains during their growth. [ABSTRACT FROM AUTHOR]

An abstract of the article "Development of a Flux Stabilizer for Solid-state Nuclear Magnetic Resonance with a Hybrid Magnet," by Kenjiro Hashi and colleagues is presented.

We report on photon coincidence measurement in a single GaAs self-assembled quantum dot (QD) using a pulsed excitation light source. At low excitation, when a neutral exciton line was present in the photoluminescence (PL) spectrum, we observed nearly perfect single photon emission from an isolated QD at 670 nm wavelength. For higher excitation, multiple PL lines appeared on the spectra, reflecting the formation of exciton complexes. Cross-correlation functions between these lines showed either bunching or antibunching behavior, depending on whether the relevant emission was from a biexciton cascade or a charged exciton recombination. [ABSTRACT FROM AUTHOR]