Examinations on the radiative extinction functions in a cylindrical medium

Examining the derivation and physical meaning of the extinction function K(τ₀η, τ₀η₁) which prescribes the radiative contribution of fluid elements in the cylindrical homogeneous media, the authors introduce the alternative functions $\text{M(τ}{}_0\text{η,τ}{}_0\text{η}{}_1\text{) = ?}{}_1{}^{\mathrm{\infty }}\text{[K}{}_1\text{(τ}{}_0\text{η}{}_1\text{t) I}{}_0\text{(τ}{}_0\text{ηt)?t] dt (η ≦ η}{}_1\text{)}$ and $\text{N(τ}{}_0\text{η, τ}{}_0\text{η, τ}{}_0\text{η}{}_1\text{) = ?}{}^{\mathrm{\infty }}{}_1\text{[K}{}_0\text{(τ}{}_0\text{ηt)I}{}_1\text{(τ}{}_0\text{η}{}_1\text{t)?t] dt (η ≧ η}{}_1\text{)}$ which can eliminate the singularity of K(τ₀η, τ₀η₁) atη = η₁. The values of the functions M(τ₀η, τ₀η₁) and N(τ₀η, τ₀η₁) are numerically calculated and plotted for the parameter τ₀ and their characteristics are discussed in detail.Subsequently a numerical analysis is performed on the simultaneous radiative and convective heat transfer with uniform heat flux. As a result of this example, it is shown that the functions M(τ₀η, τ₀η₁) and N(τ₀η, τ₀η₁) are superior to the conventional extinction function K(τ₀η, τ₀η₁) for the numerical calculations.     

Measurement of the spin correlation parameters Axx and Ayy for proton-proton scattering at 47.5 MeV

A measurement of the spin correlation parameters A_xx(90° cm) and A_yy(90° cm) of 47.5 MeV proton-proton scattering has been performed by means of polarized beam and a polarized target.     

Doubly resonant photon echoes in a three-level system

This paper deals with the photon echoes associated with two optical pulses of different frequencies, resonant to a three-level system, and reveals the existence of anomalous echoes, appearing at times corresponding to the correlations between the inhomogeneous broadenings for different spectral lines. The intensities, direction of propagation and polarizations of the echoes are analyzed quantitatively.     

Polymerization of phenylpropynes

The polymerization of phenylpropynes was investigated. Cream-coloured powders, with $\text{M}$_n between 3000 and 8500, were obtained from phenylpropynes using WCl₆·tetraphenyltin; the rate was much smaller than that for the corresponding phenylacetylene. The magnitudes of the ring-substituent effects on the reactivity of phenylpropyne catalyzed by WCl₆ were p⁺ = ?0.96 towards a phenylacetylene propagating end and p⁺ = ?2.19 towards a styryl end. These findings suggest that the former proceeds by metathesis and the latter polymerizes by a conventional cationic mechanism. Introduction of a β-methyl group on phenylacetylene decreased the reactivity by a factor of 1.5–1.8, towards a styryl cation. The polymerization mechanism of phenylpropyne is discussed on the basis of these data.     

Effects of crown ether on hydrogenation over nickel and cobalt boride catalysts: effects in catalyst preparation and effects as additives

The nickel and cobalt boride catalysts prepared in the presence of crown ethers show different selectivities from the ordinary boride catalysts in the reduction of cycloalkene, styrene oxide, and 4-t-butylcyclohexanone.     

Preliminary experiment of fluorescent X-ray computed tomography to detect dual agents for biological study

The simultaneous observation of various information, such as blood flow, tissue metabolism and distribution of receptors, is quite important in order to understand the functional state of biomedical objects. The simultaneous detectability of contrast agents by fluorescent X-ray computed tomography (FXCT) with synchrotron radiation is examined in this study. The system consisted of a silicon (111) double-crystal monochromator, an X-ray slit system, a scanning table, a PIN diode, a highly purified germanium detector and an X-ray charge-coupled device (CCD) camera. The monochromatic X-ray beam energy was adjusted to 37.0 keV and collimated into a pencil beam of 1 x 1 mm. The fluorescent spectra of the K alpha lines for iodine and xenon were detected simultaneously. FXCT could image the distribution of both iodine and xenon agents in a phantom clearly and the contrast ratio was significantly better than that of transmission X-ray computed tomography images.     

Alkane oxidation via photochemical excitation of a self-assembled molecular cage

The photoexcitation of a self-assembled M6L4-type coordination cage accommodating photochemically inert alkane guests (e.g., adamantane and cyclooctane) led to the regioselective oxidation of the guest within the cage. Under anaerobic conditions, the guest oxidation was accompanied by the stable radical formation as indicated by ESR spectrometry (g = 2.002) and change in solution color (from colorless to blue). These phenomena were shown to be characteristic of the self-assembled molecular systems: i.e., from the M6L4 supersetGn assembly, none of the components (M, L, or G) can be eliminated for the unusual oxidation and/or radical formation.     

Single-walled carbon nanotubes acquire a specific lectin-affinity through supramolecular wrapping with lactose-appended schizophyllan

Single-walled carbon nanotubes can be entrapped within a helical superstructure composed of schizophyllan bearing lactoside-appendages to show an excellent water-solubility as well as a specific lectin-affinity.