Electroweak interactions at an infinite sublayer quark level. II

It is shown that the standard model of the electroweak interactions holds at an infinite sublayer quark level, insofar as we consider the weak isospin doublet (u _{L,u L} ^cp , whereu is an infinite number of quarks at an infinite sublayer level.     

Hyperfine magnetic fields in Fe−Co alloys and their tempera ture dependences

We obtained⁵⁷Fe hyperfine field parameters from Fe₁−x-Co _x alloys (0≤x≤0.6) from 77 K to 900 K. We first discuss the origin of the low temperature hyperfine fields in terms of the 3d and 4s electrons at⁵⁷Fe atoms. The⁵⁷Fe hyperfine magnetic field (hmf) of Fe-Co alloys depends more weakly on temperature than the hmf of pure Fe. This temperature dependence occurs because the alignment of the magnetic moments at both the Fe atoms and at the Co atoms depend on temperature in the same way as the bulk magnetization of Fe-Co alloys.     

Operator inequalities and construction of Krein spaces

Let be a Hilbert space. A continuous positive operatorT on uniquely determines a Hilbert space which is continuously imbedded in and for which with the canonical imbedding . A Kreîn space version of this result, however, is not valid in general. This paper provides a necessary and sufficient condition for that a continuous selfadjoint operatorT uniquely determines a Kreîn space ( ) which is continuously imbedded in and for which with the canonical imbedding .     

Separation of Isotopes of Lithium and Uranium by Electromigration Using Cation-Exchange Membranes

Isotope separation by chromatographic electromigration has been studied for lithium (⁶Li and ⁷Li) and uranium (²³⁵U and ²³⁸U), using cation-exchange membranes as migration media. The membranes were pulled back against the direction of the movement of isotopic cations in a countercurrent manner. In both cases of the elements the lighter isotope, ⁶Li or ²³⁵U, was concentrated at the frontal part of a migration zone; at the extreme front the ⁶Li atom % increased to 16.8% from the original value of 7.5% after 386 cm migration, and the ²³⁵ U atom % rose to 0.743% from the original value of 0.723% after 200 cm migration. Isotope separation coefficients were experimentally determined: ε = (3.7 ± 0.4) μ 10^?3 for lithium isotopes, and two slightly different values ε = (4.9 ± 1.0) μ 10^?5 and (5.4 ± 1.1) μ 10^?5 for uranium isotopes. The steep isotope accumulation was observed in a narrow boundary region. A mathematical expression for the isotope accumulation curve was derived, and the slope of the curve was assessed for each experimental result.     

Organic thin‐film transistor fabricated between flexible films by thermal lamination

We propose a novel and complementary method for fabrication of flexible electronics. This method is not based on conventional printing using inks, but is based on the application of a toner‐based method such as Xerox or laser printing, followed by a lamination process. The lamination method is a solvent‐free and material‐saving process that simultaneously seals the devices, and the fabricated flexible devices have structural durability against bending. We have also shown that thermal lamination has an oriented growth effect, and the electrical characteristics of flexible organic field‐effect transistors did not degrade under a bending radius of 1 mm.

     

Nitromethane pyrolysis in shock tubes and a micro flow reactor with a controlled temperature profile

Nitromethane has many applications, such as in racing, as a gasoline fuel additive, and as a monopropellant. Despite a large number of studies and the small size of the molecule, the combustion chemistry of nitromethane is still not well understood. To improve models, the pyrolysis of nitromethane (CH₃NO₂) was investigated experimentally in shock tubes and in a micro flow reactor with a controlled temperature profile (MFR), under dilute conditions. Several spectroscopic diagnostics were used in the shock tubes to follow the concentration time histories of CO, H₂O (both using IR laser absorption), and CH₃NO₂ (UV light absorption). A quadrupole mass spectrometer was used to measure CH₃NO₂, NO₂, CH₄, C₂H₄, and C₂H₂ at various temperatures with the MFR. These unique experimental results were compared to modern, detailed kinetics models from the literature, and no mechanism was able to reproduce these data over the wide range of conditions investigated. Predictions for the CO and H₂O levels were generally inaccurate, and the CH₄, C₂H₄, and C₂H₂ predictions were poor in most cases for the MFR data. Importantly, all models largely differ in their predictions. A numerical analysis was performed to identify ways to improve the next generation of nitromethane models. Results indicate that nitromethane decomposition needs to be improved below 1050 K, and that hydrocarbon-NOx interactions still need to be further investigated.     

Third-order resonant optical nonlinearity from trans–cis photoisomerization of an azo dye in a rigid matrix

 We investigated the trans–cis photoisomerization of an azo dye in a rigid matrix and the resulting third-order resonant optical nonlinearity by means of the simple theoretical prediction of a two-energy-level system, thin-layer chromatography and H-NMR studies. A methylorange (MO), a methylred (MR), congored (CR) or a Disperse Red 1 (DR1) doped polyvinyl alcohol (PVA) or silica film was used as nonlinear optical material. The existence of equi-absorbing points, or isosbestic points in the absorbance spectrum change and the remarkable stationary transmittance to be independent of the action beam intensity enabled us to confirm the photoisomerization even in a rigid matrix. Then, we measured the third-order resonant optical nonlinearity of dichroism through the polarization absorbance spectrum measurement and determined the characteristic optical parameters of the photoisomerization in the film such as the quantum yields φ_T, φ_C, the thermal reaction constant K and the photoisomerization time constant by fitting the theoretical curve of the two-energy-level system to the observed temporal transmittance change after the action beam exposure of the MO/PVA film. The quantum yields were φˉ_T=0.36 and φˉ_C=0.38, respectively. The photoisomerization time constant of MO embedded in the PVA film was a few seconds. The thermal reaction constant K depended on the excitation beam intensity. Received: 20 June 1996/Revised version: 4 October 1996     

Convenient preparation of dichloromethyl alkyl ethers

Dichloromethyl alkyl ethers have been synthesized from alkyl formates (C1–C4) and oxalyl chloride in the presence of catalytic amount of N-methylformanilide. N,N-Dimethylformamide is not suitable for the reaction. The method has the advantages of simple experimental procedure, which is applicable to large scale synthesis, without use of harmful reagents.     

Development of a scanning microscopy by total internal reflection coupled with thermal lens spectroscopy

Non-destructive measurement of a small region on a solid/liquid interface is of great importance in physical chemistry and biochemistry, especially in the research of thin films and cell membranes. Optical methods for surface analysis with high lateral resolution are suitable methods for monitoring them. We now report a new scanning optical microscopic method to which total internal reflection coupled with a thermal lens technique was introduced. Its lateral resolution was estimated both experimentally and theoretically. To experimentally estimate the resolution, the grid patterns of thin photoresist films with well-defined lateral structures were measured. The experimental resolution was about 45 microm, which was almost same as the diameter of the excitation beam at a glass/sample interface. From this result, it was verified that this new scanning microscopy ideally worked.     

Investigation of evolution hydrocarbon species on a Si surface during methane plasma with and without substrate bias, using infrared spectroscopy in multiple internal reflection geometry

We investigated evolution of hydrocarbon species on a Si surface during methane plasma both with and without substrate bias, using infrared spectroscopy in multiple internal reflection geometry (MIR-IRAS). We found that the relative density of the sp³-CH or sp³-CH₂ species to the sp³-CH₃ species was low in the low exposure regions, but that the relative density of the sp³-CH or sp³-CH₂ species increased as the exposure was higher. Substrate temperatures rose as the plasma exposure was higher. The changes of ratios would be ascribed to the substrate heating effect by plasma exposure, which would enhance the etching and/or hydrogen abstraction effects. We also found the change of CH_1-2/CH₃ ratios was enhanced when the high substrate bias was applied. The enhancement of the ratio was due to ion effects.