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Volume 69, Issue 1
Displaying 1-4 of 4 articles from this issue
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Hiroo KAGAMI, Shigeru IIZUMI, Masatoshi IWATA, Terukazu NUREKI1993 Volume 69 Issue 1 Pages 1-6
Published: 1993
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSBased on new and previously published Sr and Nd isotope data, we examined the petrogenetic relationship between deep crust- and upper mantle-derived xenoliths contained in Cenozoic volcanic rocks and Cretaceous-Paleogene granitoid rocks in SW Japan. The deep crust- and upper mantle-derived mafic to ultramafic xenoliths contained in Cenozoic volcanic rocks from SW Japan have comparable initial Sr and Nd isotope ratios to the Cretaceous-Paleogene granitoid rocks in their respective districts. This may suggest that these xenoliths were genetically related to the Cretaceous-Paleogene granitoid rocks in SW Japan, and that regional variations in Sr and Nd isotope ratios observed in the granitoid rocks are attributed to differences in the geochemistry of the magma sources.View full abstractDownload PDF (733K) -
Tomiki IKEDA, Takeo SASAKI, Seiji KURIHARA1993 Volume 69 Issue 1 Pages 7-12
Published: 1993
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSPhotoirradiation of films of polymer liquid crystals (PLCs) with mesogenic phenyl-benzoate side-chains containing a small amount of photoresponsive guest molecules such as azobenzene derivatives, to bring about traps-cis isomerization of the guest molecule, resulted in an isothermal nematic to isotropic phase transition of the guest/host mixtures at the irradiated sites; thus, optical image could be stored with a high contrast ratio. Excellent film-forming properties of PLCs enables cell-free performance of the optical image recording systems. Furthermore, owing to the glass transition temperature (Tg) of PLCs, the stored image could be kept very stable for a long period below Tg. The photochemical phase transition of the guest/host mixtures was reversible: cis-trans back-isomerization restored the initial state, so that the image is rewritable. Resolution was found to be -2μm and response was in the range of 50ms to 200ms, which was comparable or even faster than that of low-molecular-weight liquid crystals.View full abstractDownload PDF (664K) -
Shinichi SAKURAI, Hiromitsu KAWADA, Takeji HASHIMOTO, Lewis J. FETTERS1993 Volume 69 Issue 1 Pages 13-17
Published: 1993
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSThermoreversible morphological transition of a poly(styrene-block-isoprene) (SI) block copolymer was studied by small-angle X-ray scattering and transmission electron microscopy (TEM). Although block copolymers are theoretically predicted to exhibit a reversible morphological change between lamellae and disordered state via cylinders and spheres with temperature, this thermoreversibility in morphology transition has not been experimentally confirmed yet. In order to study this thermoreversible transition, the SI diblock copolymer may have to have a biased composition and sufficient mobility. To meet these requirements, we used the SI with the weight fraction of polystyrene (PS) 0.16 and with a relative low number-average molecular weight 8.2×104. Heat treatments of the specimen were carefully conducted. Moreover, the ultrathin sectioning was performed by cryo-ultramicrotomy at -85°C for TEM studies. The cylindrical and spherical microdomains of PS which are embedded in the polyisoprene matrix were thermoreversibly observed at 150 and 200°C, respectively.View full abstractDownload PDF (871K) -
Lichenized AscomyceteYasuhiro KINOSHITA, Satoko HAYASE, Yoshikazu YAMAMOTO, Isao YOSHIMURA, ...1993 Volume 69 Issue 1 Pages 18-21
Published: 1993
Released on J-STAGE: October 13, 2006
JOURNAL FREE ACCESSFilamentous outgrowths consisting of mycobiont tissue only are produced on cultured fragments of Usnea hirta. The anatomy of these “thallus-like filaments” is similar to the naturally growing thallus consisting of a central axis surrounded by a medulla and a cortex. The filaments also contained the lichen substance usnic acid. Similar filaments were produced in four species (U. filipendula, U. flexilis, U. roseola, U. rubicunda) of the 12 tested. This result confirms that mycobionts play an important role in the morphogenesis of the lichen.View full abstractDownload PDF (3180K)
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