Exact coverings of 2-paths by hamilton cycles

We construct a C(2m, 2m, 2) design which is a family of Hamilton cycles in K_2m so that each 2-path of K_2m lies in exactly two of the cycles.     

Electron swarm parameters in SiH4-rare gas mixtures andcollision cross sections for monosilane molecules

Previously measured drift velocities and longitudinal diffusion coefficients in SiH₄-Ar mixtures were reanalyzed, and the new vibrational excitation cross sections for monosilane molecules were obtained. Not only were the new cross sections consistent with swarm parameters, but also the ratio of their magnitudes at the resonance peak agreed with earlier measurements of the electron beam experiment. Having known the vibrational excitation cross sections, the analysis of the primary ionization coefficient measured in SiH₄-Kr mixtures led to a consistent inelastic cross section, which possibly corresponds to the total section for neutral dissociations for the molecule. It was confirmed that the derived set of the cross sections also gave good agreement with the electron swarm parameters measured in pure monosilane gas     

Existence theorems of a maximum likelihood estimate from a generalized censored data sample

Summary A new type of random sample, called a generalized censored data sample, is defined. An approach to finding criteria for the existence of a maximum likelihood estiamte from a finite generalized censored data sample is presented. This approach, named the probability contents boundary analysis, gives systematically a number of practical criteria, each of which is effective for various kinds of typical distribution families in statistical analysis.     

An analysis of medium noise of Co-Cr double-layer films in perpendicular magnetic recording

The medium noise in perpendicular magnetic recording is discussed. The perpendicular recording mode was expected to prevent zig-zag walls around transitions, and the experimental result of low transition noise in Co-Cr media confirms this. Also, the main origin of the noise is concluded to be irregular clusters of grains in the film.     

The regioselective alkylation of 4,6-dimethyl-1-phenyl-2(1H)-pyrimidinone

4,6-Dimethyl-1-phenyl-2(1H)-pyrimidinone (I) was treated with alkyl halides in the presence of sodium hydride at low temperature to afford only C-6 alkylated products III and IV in good yields. Further, the mono-, IIIa-d, and di-alkylated 2(1H)-pyrimidinones IVa-d were selectively obtained by changing the amount of alkyl halides.     

Keramadine,a novel antagonist of serotonergic receptors isolated from the okinawan sea sponge Agelas sp.

A new bromine-containing alkaloid, keramadine, has been isolated from the Okinawan sea sponge Agelas sp. as a novel antagonist of serotonergic receptors and its structure has been elucidated by n.m.r. spectrometry.     

PHYTOCHROME SYNTHESIS DURING IMBIBITION IN EMBRYONIC AXES OF Pisum sativum L.*

Abstract— The exact quantity of phytochrome in crude homogenates (2kS) prepared from embryonic axes of Pisum sativum during imbibition at 25°C on 0,2% agar was estimated optically. The problem of the scattering factor was solved by using highly purified phytochrome as an internal standard. The content of phytochrome protein moiety in diluted samples of the crude homogenates of the axes was also determined by an enzyme-linked immunosorbent assay (ELISA). Phytochrome was not detectable either spectropho-tometrically or immunochemically in 2kS of dormant dry axes. Embryonic axes quickly absorbed water during the first1–2 h after the start of imbibition, after which the fresh weight stayed at a constant level for a further 10 h. The content of spectrophotometrically detectable phytochrome increased during imbibition in the dark, reaching about 0.2 μ.g/axis after 12 h. The amount of phytochrome in 2kS of axes in the light was so small that only about 0.05 μg/axis was detected after 12 h. The content of immunochemically detectable phytochrome greatly increased up to ca. 0.5 μg/axis after 12 h of dark incubation. In 2kS of the light-grown axes the content of the phytochrome protein was ca. one fourth lower than in dark-grown axes. We conclude that the appearance and increase of phytochrome in fragments of imbibed embryonic axes were caused by de novo synthesis and that the contents of both photometrically detectable phytochrome and its protein moiety in the light-grown samples were lower than those in the dark throughout the early germination process.     

Solution space of discrete Wiener-Hopf equations and Grassmann manifold

It is shown that the solution space of a system of discrete Wiener-Hopf equations is a set of points on an infinite-dimensional Grassmann manifold. Fractional transformations acting on the solution space are also discussed.     

Transformation of resonant Raman scattering into luminescence in CdxZn1−xTe mixed crystals: Time-resolved spectroscopy

We report an experimental study of time characteristics of secondary emission in Cd_xZn_1-xTe mixed crystals (x = 0.32) under resonant excitation with a picosecond dye laser. When the incident laser frequency is tuned on to the luminescence maximum of localized excitons, the decay curve of the intensity of “Raman-like” lines exhibits a single exponential decay. Off resonance, however, a short-lived component corresponding to Raman scattering appears in addition to the long-lived component. The intensity of the Raman component relative to that of the luminescence component increases with increase of the off-resonance frequency. From these temporal behaviors, we have found, for the first time, the transformation of resonant Raman scattering into luminescence in mixed crystals as a function of incident frequencies.     

Analytical and numerical studies of angular correlation function of waves scattered from randomly distributed cylinders

The analytical solution for the angular correlation function of scattered waves from randomly distributed infinitely long cylinders is obtained using the second-order approximation with a modified attenuation coefficient. The approach is based on the coherent summation of the scattered waves which preserves the interference effects such as backscattering enhancement. The modification of the transport attenuation coefficient includes the contribution due to the incoherent wave. By comparing with the exact numerical simulations, we found that the correction factor is given by (1-μ¯) which also appears in the diffusion equation. The present approach gives good agreement with numerical and experimental results.