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81.
Yukihiro Okada Manabu Mizutani Fuyuhiko Ishii Jun Nishimura 《Tetrahedron letters》1997,38(52):5347-9016
The modification of title compounds to chiral receptors and their characterization are reported. The two synthetic methods were developed. The racemates obtained could be resolved to each stable enantiomer by a chiral HPLC column. Chiral calixarenes were designed as the receptors with planar chirality. The (−)-receptor strongly forms 1:1 complex with (R)-(+)--phenylethylammonium picrate. 相似文献
82.
83.
Nobuhiro Kawatsuki Ryoji Tsutsumi Akie Hiraiwa Hirofumi Takatsuka Takeya Sakai 《Journal of polymer science. Part A, Polymer chemistry》2008,46(14):4712-4718
Thermally enhanced photoinduced in‐plane molecular reorientation in new photo‐cross‐linkable polymer liquid crystalline (PPLC) films comprising 4‐[ω‐(4‐methoxycinnamoyloxy)alkyloxy]biphenyl side groups is explored using linearly polarized ultraviolet (LPUV) light exposure and subsequent annealing. The influence of the alkylene spacer length between the photo‐cross‐linkable group and the biphenyl mesogenic moiety is investigated. The straight‐line characteristics of the photoreactive mesogenic side group and the 4‐methoxycinnamoyl group play important roles in the high photoreactivity and the large thermally enhanced molecular reorientation, where the in‐plane order and the birefringence of the reoriented film are 0.61 and 0.18 are obtained. Finally, cooperative molecular reorientation of dichroic dyes doped in PPLC films is also achieved to fabricate a linear polarizer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4712–4718, 2008 相似文献
84.
85.
86.
Kinoshita T Haga Y Narimatsu S Shimada M Goda Y 《Chemical & pharmaceutical bulletin》2005,53(6):717-720
New cassane diterpene-acids, neocaesalpins H and I, were isolated from the leaves of Caesalpinia crista (Fabaceae), and their structures were deduced on the basis of the spectroscopic and chemical basis. These compounds were characterized as having an alpha,beta-butenolide hemiacetal ring that is rare in nature. The lacking of 5-hydroxy group also distinguished neocaesalpins H and I from cassane diterpenes (caesalpins) occurring in other Caesalpinia species from the phytochemical viewpoint. The nomenclature of three Caesalpinia species was also reviewed, and it was found that some species belonging to the genus Caesalpinia are improperly named and should be changed to valid names. 相似文献
87.
88.
Ohne Zusammenfassung 相似文献
89.
Akihiro Tsutsumi Kunio Hikichi Motozo Kaneko Jiro Furuichi 《Journal of Polymer Science.Polymer Physics》1968,6(3):493-498
Nuclear magnetic resonance of poly-β-alanine samples differing in solubility in water was studied over a wide temperature range as part of an investigation of their physical properties. Water-soluble poly-β-alanine has more branches and a lower degree of crystallinity than water-insoluble poly-β-alanine. NMR spectra of poly-β-alanine show one component at 77°K. which splits into two components, broad and narrow, at room temperature. Two transition regions were observed in curves for line width and second moment versus temperature. The higher transition temperature, corresponding to the glass transition of the polymer, appears to decrease with increasing water content. The second moment for the water-soluble polymer differs from that of the water-insoluble polymer at 77°K. This is interpreted in terms of the difference in the degree of crystallinity of the polymers. 相似文献
90.
When a diffuser is illuminated by the coherent light with a negative power-law distribution, fractal speckles are produced
in the far-field diffraction region. Fractal speckles have extremely long spatial correlation functions of the intensity distributions
in comparison with ordinary speckles, which implies that they may extend measurement ranges in various metrological applications
based on the spatial correlation of speckles. To have fractal speckles with satisfactory statistical properties, it is required
to produce a power-law illumination profile with high quality. In this paper, we report on the computer-generated holograms
for producing power-law intensities on the basis of the method of stationary phase, with the error-reduction algorithm combined
with to suppress strong ringing of the intensity. 相似文献