Investigation of SO3 absorption line for in situ gas detection inside combustion plants using a 4-µm-band laser source.

We have investigated 4-µm-band SO3 absorption lines for in situSO3 detection using a mid-infrared laser source based on difference frequency generation in a quasi-phase-matched LiNbO3 waveguide. In the wavelength range of 4.09400-4.10600 µm, there were strong SO3 absorption lines. The maximum absorption coefficient at a concentration of 170 ppmv was estimated to be about 3.2×10-5 cm-1 at a gas temperature of 190°C. In coexistence with H2O, the reduction of the SO3 absorption peak height was observed, which was caused by sulfuric acid formation. We discuss a method of using an SO3 equilibrium curve to derive the total SO3 molecule concentration.

Highly reversible capacity at the surface of a lithium-rich manganese oxide: a model study using an epitaxial film system.

Epitaxial films of Li2MnO3 were synthesized using pulsed laser deposition. A 12.6 nm film exhibited a high discharge capacity of over 300 mA h g(-1) following its fiftieth cycle and better stability than 29.8 and 47.8 nm films. The surfaces of such films are intrinsically active at the electrochemical interface.

Giant magneto-elastic coupling in multiferroic hexagonal manganites.

The motion of atoms in a solid always responds to cooling or heating in a way that is consistent with the symmetry of the given space group of the solid to which they belong. When the atoms move, the electronic structure of the solid changes, leading to different physical properties. Therefore, the determination of where atoms are and what atoms do is a cornerstone of modern solid-state physics. However, experimental observations of atomic displacements measured as a function of temperature are very rare, because those displacements are, in almost all cases, exceedingly small. Here we show, using a combination of diffraction techniques, that the hexagonal manganites RMnO3 (where R is a rare-earth element) undergo an isostructural transition with exceptionally large atomic displacements: two orders of magnitude larger than those seen in any other magnetic material, resulting in an unusually strong magneto-elastic coupling. We follow the exact atomic displacements of all the atoms in the unit cell as a function of temperature and find consistency with theoretical predictions based on group theories. We argue that this gigantic magneto-elastic coupling in RMnO3 holds the key to the recently observed magneto-electric phenomenon in this intriguing class of materials.

A novel mutation in the gene for canine acid beta-galactosidase that causes GM1-gangliosidosis in Shiba dogs.

A homozygous recessive mutation, causing GM1-gangliosidosis in Shiba dogs, was identified as a deletion of C nucleotide 1668 in the gene for canine acid beta-galactosidase, which was a novel mutation in canine GM1-gangliosidosis.

Tetranuclear mixed-metal M(II)2Cu(II)2 complexes derived from a phenol-based macrocyclic ligand having two N(amine)2O2 and two N(imine)2O2 metal-binding sites.

The reaction of N,N'-dimethyl-N,N'-ethylenebis(5-bromo-3-formyl-2-hydroxybenzylaminato)copper(II) with ethylenediamine in aqueous DMF with excess perchloric acid resulted in the [2:2] cyclic condensation of the constituents, providing the dinuclear Cu(II) complex [Cu2(H2R)](ClO4)2. It crystallizes in the monoclinic space group P2(1)/c, with a = 19.603(3) A, b = 13.370(2) A, c = 21.072(3) A, beta = 98.87(1) degrees, V = 5456(1) A3, and Z = 4. The ligand R4- has two N(amine)2O2 and two N(imine)2O2 metal-binding sites sharing two phenolic oxygens, and [Cu2(H2R)](ClO4)2 has the two Cu(II) ions in the N(imine)2O2 sites and two protons in the N(amine)2O2 sites. [Cu2(H2R)](ClO4)2 was converted by neutralization into [Cu2(R)], from which mixed-metal Cu(II)2M(II)2 complexes [Cu2M2(R)Cl4] (M = Co(II), Ni(II), Zn(II)) were derived. [Cu2Co2(R)Cl4]*2CHCl3*H2O crystallizes in the monoclinic space group C2/c, with a = 32.514(3) A, b = 12.246(3) A, c = 19.827(2) A, beta = 126.082(1) degrees, V = 6380(1) A3, and Z = 4. [Cu2Zn2(R)Cl4]*2CHCl3*H2O crystallizes in the monoclinic space group C2/c, with a = 32.53(1) A, b = 12.242(2) A, c = 19.729(9) A, beta = 126.03(3) degrees, V = 6354(4) A3, and Z = 4. The two complexes are isotructural and have a dimer-of-dimers structure with two separated Cu(II)M(II) units. In each dinuclear unit, the Cu(II) is bound to the N(imine)2O2 site and the M(II) is bonded to a phenolic oxygen and two nitrogens of the N(amine)2O2 site. The Cu(II) and M(II) ions are bridged by a phenolic oxygen and an exogenous chloride ion. The Cu(II)2Ni(II)2 complex has a defect double-cubane structure. Cryomagnetic studies for the Cu(II)2Co(II)2 complex indicate an antiferromagnetic spin-exchange interaction within each dinuclear Cu(II)Co(II) unit (J = -9.5 cm(-1) based on H = -2JS(Cu)S(Co)). The Cu(II)2Ni(II)2 complex shows a weak antiferromagnetic interaction between the adjacent Cu(II) and Ni(II) ions (-3.5 cm(-1)) and a weak ferromagnetic interaction between the two Ni(II) ions (+2.0 cm(-1)).

Temporal solitons in second-harmonic generation with a noncollinear phase-mismatching scheme.

A noncollinear second-harmonic-generation scheme that includes two gratings and a nonlinear optical crystal generates temporal solitons with a noncollinear phase mismatch and frequency-chirped laser pulses. At 180-fs pulse duration, 25-GW/cm2 fundamental intensity, -7647.3-m(-1) wave-vector mismatch, 66-fs delay time, and +/-3.07163 x 10(25) s(-2) frequency-chirp rates, temporal solitons with durations from 139 to 155 fs and Gaussian shapes can be obtained. The corresponding conversion efficiency is greater than 40%.

Efficient type I second-harmonic generation of subpicosecond laser pulses with a series of alternating nonlinear and delay crystals.

We propose a novel configuration of efficient type I second-harmonic generation (SHG) with ultrashort laser pulses by group-velocity compensation. The configuration is composed of a type I SHG crystal and a series of alternating time-delay and type I SHG crystals. The numerical calculations show that the conversion efficiency can be increased to almost 100% by using crystal pairs in series, and the duration of the second-harmonic pulse is almost the same as that of the fundamental pulse.

Multipass Michelson interferometer with the use of a wavelength-modulated laser diode.

An improved multipass Michelson interferometer is implemented. This technique uses the fact that the wavelength of a laser diode varies in proportion to the diode's injection current. With this method the sensitivity augmentation is accomplished by inserting a beam splitter into one arm of the interferometer, resulting in multiple reflections between the end mirror and the beam splitter. In addition, the interference of laser beams reflected from two arms can be accomplished with unequal arms in the condition of a short coherence length. The sensitivity increase of interference fringes and the compensation of the short coherence length have been demonstrated in experiments.

Wavelength-change characteristics of semiconductor lasers and their application to holographic contouring.

The dependence of double-heterostructure AlGaAs semiconductor laser wavelength on injection current and temperature was investigated by means of a Michelson interferometer. The lasers operated in a single longitudinal mode at 790 nm, permitting them to be applied to two-wavelength holographic contouring. Continuous change and discontinuous change by mode hopping were observed. The wavelength was continuously tunable by variation of injection current and temperature at rates of 0.0045 nm/mA and 0.070 mm/ degrees C, respectively. Discontinuties in wavelength change were observed to be integer multiples of the longitudinal mode spacing. Holographic contour fringes were interpreted given the measured variation in wavelength.

Holographic contour generation by spatial frequency modulation.

A contouring method by spatial frequency modulation using hologram interferometry is presented. The principle is that Young's fringes produced by tilting the illumination ray are modulated by the object shape and demodulated by tilting the observation ray to generate depth contours. The problems of fringe localization and visibility in the arrangements of Fresnel holography and Fourier transform holography are studied. This method has the advantages that the sensitivity and the standard plane orientation are continuously variable, and high sensitivity and large measurable depth can be achieved for diffuse surface objects.

Endoscopic hologram interferometry using fiber optics.

Basic and practical problems on the formation of fringes in endoscopic hologram interferometry using fiber optics have been studied in connection with medical diagnosis of living body cavities, nondestructive testing of inner parts of machines, etc. It is pointed out that fiber bundles instead of single fibers can be used to transmit high power laser light for object illumination to prevent the light path break induced by the high power density of concentrated laser light. The effects of extended source illumination by the fiber bundle, image transmission through the ordered fiber bundle, and fiber bundle movement on the fringe visibility were investigated.

[Local Schwartzman phenomenon in axenic rabbits]. / Etude du phénomène de Schwartzman local chez le lapin axénique

Local Schwartzman phenomenon was produced by coli-endotoxin in all the germfree rabbits tested (11 in all) at the age of 102 to 135 days. Any kinds of natural antibodies were not detected in sera of the rabbits, which in fact were found to be agammaglobulinaemic in most cases, as revealed by immunoelectrophoresis. These facts suggested that the germfree rabbits utilized here had not been sensitized to bacterial endotoxins. From the results obtained here, it may be concluded that the existence of hypersensitivity to endotoxin is not necessary to the production of local Schwartzman phenomenon by bacterial endotoxin.