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A novel fast T-type photochromic molecular system, 1,2-diarylbenzene, was successfully developed.

Morphological and evolutional features of Ellerman bombs were studied with He filtergrams of two active regions very close to the solar limb. We quantitatively determined the elongated or spike-like shape of the bomb. The mean apparent length of 174 bombs is 1.1 arc sec, while 80 % of 204 bombs have a diameter of less than 0.6 arc sec. The mean lifetime of 77 bombs is about 12 min at Hc~ -1.2 A. The first maximum brightness of a typical bomb is attained, on average in about 2 min. Bombs grow longer in the first brightening phase and their mean upward velocity explains the blue asymmetry of He emission profiles of moustaches.

The first synthesis of (-)-pericosine E (6), a metabolite of the Periconia byssoides OUPS-N133 isolated originally from the sea hare Aplysia kurodai, has been achieved. Efficient and regioselective synthetic procedures for the synthesis of key intermediates, anti- and syn-epoxides 9 and 10, were developed using an anti-epoxidation of diene 12 with TFDO and a bromohydrination of 12 with NBS in CH(3)CN/H(2)O (2:3), respectively. In addition, comparison of the specific optical rotations between synthetic 6 and natural 6 elucidated that the naturally preferred enantiomer of pericosine E had the same absolute configuration as (-)-6 synthesized from chlorohydrin (-)-8 and anti-epoxide (+)-9.

Electromagnetic vibrations, which are generated by simultaneous imposition of a static magnetic field and an alternating electric field, were applied to the refinement of crystal grains of tough pitch copper. The electromagnetic vibrations of the frequency range from 100 Hz to 10 kHz were imposed during solidification of the copper rod. Within this frequency range, the vibration frequency of about 100 Hz was found to be the most effective in refining the copper crystal grains and the average grain size was refined up to 200 mm, which otherwise was around 600 mm in a nonvibrated specimen. It was concluded that by the electromagnetic vibration process tough pitch copper could also be refined as well as Al-Si alloys and AZ91D alloys.