Quantitative analysis of original and powdered rocks and mineral inclusions by laser ablation inductively coupled plasma mass spectrometry

Direct analysis of rocks by laser ablation inductively coupled plasma mass spectrometry is described. Both powdered standard rocks and the original rocks were analysed and the results agreed with each other in spite of the difference in the surface states. Microprobe analysis of biotite in granite JG1 was also done directly with a focused laser beam and the results obtained were very close to the solution values given by the conventional aqueous method using biotite separated from an original rock. For quantitative analysis, the measured signal intensity was normalized either by the ablated weight or the barium signal intensity. Forty-two major and minor elements (two of them being used as internal standards) in twelve standard rocks fromt the igneous rock series of the Geological Survey of Japan were determined successfully.     

Novel enhancement of the reducing ability of ytterbium diiodide by irradiation with near-UV light

Irradiation with near-UV light, dramatically enhances the reducing ability of ytterbium diiodide (YbI₂). Organic bromides, iodides, tosylates, and tellurides are reduced efficiently by a YbI₂-hv system, while these can not be reduced with YbI₂ in the dark.     

Vibration measurement by vibrating-plate holograms

If a hologram of a vibrating object is recorded on a photographic plate which vibrates synchronously with the object, the reconstructed image produces equi-amplitude fringes of the object vibration, the amplitude of which is reduced by a constant determined from the amplitude of the plate vibration. This phenomenon can be used as a method to extend the measurable range of vibration amplitudes, and some experimental results are shown.     

Exciton and magneto-absorption in tellurium

Infrared magneto-absorption has been investigated in tellurium crystals in magnetic fields up to 45 koe at liquid helium temperatures. When the magnetic field was applied parallel or perpendicular to the c-axis, oscillatory absorptions with many transmission minima involving the exciton absorption were observed. The results were analysed taking into account the complicated structure of the valence band.     

Stereospecific synthesis of chiral precursors of thienamycin from L-Threonine

L-Threonine was transformed, stereospecifically, to a versatile β-lactam (5a) in 3 steps. This β-lactam was further converted to a key intermediate (25) for the synthesis of thienamycin and its biologically active analogues. Furthermore, the compound 5a was changed to iodides (18 and 23), cyanides (19 and 24), chloromethylketone (26) and aldehydes (30 and 31) which appear to have a latent potential as precursors for the syntheses of the carbapenems.     

The structure of arugomycin,a new anthracycline antibiotic part I. structural elucidation of degradation products,AG1, AG2 and AG3.

Based on ¹H- and ¹³C-NMR and mass spectral analysis and chemical degradation, the structures of degradation products of arugomycin (arugorol, AG1, AG2 and AG3) have been determined as shown in Fig. 1.     

Magnetic field dip and the lifetime of the spherical tensor element of the density matrix in a He-Ne laser

The magnetic field dips (MFD) of the 0.633 and 1.15 μm lines of a He-Ne laser are investigated. It is found that the widths of the MFD signals are not determined by a single upper or lower laser state. Thus, there is some ambiguity in the interpretation of the MFD measurement for the determination of the lifetime, which is difficult to resolve theoretically or experimentally. The effect of pressure on MFD is also discussed, with emphasis on excitation-transfer collisions between the excited and ground states of neon atoms.