Studies of lattice dynamics in 2HTaS2 by Raman scattering

Raman spectra are presented in the high and low temperature phases of 2H-TaS₂. In the normal phase at 380 K one A_1g- and two E_2g-modes have been observed at 400, 27 and 286 cm^-1, respectively. In the charge density wave state two extra peaks appear with strong scattering intensity in E_2g- symmetry and weak in A_1g-symmetry. The E_2g peak grows and hardens toward 50 cm^-1 with decreasing temperature. The temperature dependence is very similar to the E_2g-mode in 2H-TaSe₂ of similar 3a₀ × 3a₀ superstructure. Other peaks observed in 2H-TaSe₂ in the commensurate phase are not observed. This suggests the incommensurability of the charge density wave state in 2H-TaS₂.     

Grafting of methyl methacrylate and its derivatives onto blood

The grafting of vinyl monomers by tri-n-butylborane to blood has been investigated. The infrared spectra indicated that the monomers were grafted onto blood components. The grafting seems to occur onto blood proteins, mainly onto hemoglobin. The presence of water was essential to the grafting. The hydrolysis of the graft suggests that basic amino acids in the blood proteins, such as lysine and histidine, play an important role in the grafting.     

Raman scattering in low wavenumber region as a new probe to structural properties of microcrystalline silicon

The structural properties of microcrystalline silicon (μc-Si) are studied by Raman scattering. It is found that the intensity of each Raman band closely correlates with the absorption coefficient in the interband region and that the Raman band at ca. 150 cm^?1 is a sensitive probe to randomness of Si-Si bonding structure in μc-Si.     

Self-induced transparency due to two photon transition

We show theoretically that the effect of self-induced transparency can be supported by the two-photon transition in the system of three-level atoms. The distortionless propagation of the radiation wave is composed of a train of pulses which is described by a trigonometric function, and in one limit, it approaches to a single pulse with lorentzian form for the radiation intensity.     

Total synthesis of a macrocyclic spermidine alkaloid,codonocarpine

Total synthesis of codonocarpine ($\text{5}$) and its regio-isomer ($\text{1}$$\text{5}$) utilizing a new cyclization procedure is described.     

Terbium-activated InOCI phosphor

Terbium-activated InOCI was found to show high luminous emission under cathode ray or ultraviolet excitation. This paper reports on its synthesis and emission properties.     

Association Schemes and Fusion Algebras (An Introduction)

We introduce the concept of fusion algebras at algebraic level, as a purely algebraic concept for the fusion algebras which appear in conformal field theory in mathematical physics. We first discuss the connection between fusion algebras at algebraic level and character algebras, a purely algebraic concept for Bose-Mesner algebras of association schemes. Through this correspondence, we establish the condition when the matrix S of a fusion algebra at algebraic level is unitary or symmetric. We construct integral fusion algebras at algebraic level, from association schemes, in particular from group association schemes, whose matrix S is unitary and symmetric. Finally, we consider whether the modular invariance property is satisfied or not, namely whether there exists a diagonal matrix T satisfying the condition (ST)³ = S ². We prove that this property does not hold for some integral fusion algebras at algebraic level coming from the group association scheme of certain groups of order 64, and we also prove that the (nonintegral) fusion algebra at algebraic level obtained from the Hamming association scheme H(d, q) has the modular invariance property.     

10-Gbit/s Serial Optical Interconnection for an ATM Switch

Serial optical interconnection is proposed for connections in a Torus asynchronous transfer mode switch. A cross-point switch was developed that operates at a bit rate of 20 Gbit/s. The switching operation was successfully performed using cascaded cross-point switches through an optical interconnection configuration consisting of commercial optoelectronics devices. The measured switching rate was 10 Gbit/s, and it was limited by the responses of the optoelectronics devices.     

Mössbauer spectroscopy of metals from birth to death

In today's metallurgy, precision techniques, such as X-ray and electron diffraction, electron microscopy, infrared spectroscopy and electron probe micro-analyzer, are being indispensably used, and, comparing to them, Mössbauer spectroscopy is not inferior at all in usefulness, convenience and cost benefit. Actually, however, it is not yet popular among the metallurgists probably because people believe that the Mössbauer effect is a difficult physics, radioactive sources are difficult to handle, and spectral analyses are complicated. These beliefs are in fact groundless and must be dissolved for further diffusion of this useful Mössbauer technique in metals and other industries. The present introductory talk intends to help people's better understanding and no anxiety for using the Mössbauer spectroscopy by showing how it can be applied to various problems of metals and alloys from their birth to the end, that is, from the study of minerals and ores before smelting to that of corrosion and other failures. Firstly, the principle of Mössbauer spectroscopy will be explained with simplest illustrations together with simple pictures of apparatuses including the high temperature furnace and the high pressure cell. In the second will be shown typical examples of Mössbauer patterns of magnetite, carbon steel and other alloys, with indications of how to analyze the seemingly complicated spectra. Some other examples will be shown with special apparatuses easy to measure. The usefulness and convenience of Mössbauer spectroscopy will be understood again from these examples. More examples will be on amorphous alloys and other advanced materials.