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991.
Hiroyuki Mochizuki Toshiko Mizokuro Nobutaka Tanigaki Ichiro Ueno Takashi Hiraga 《Journal of Polymer Science.Polymer Physics》2005,43(17):2307-2313
The crystallization behavior of an amorphous polymer, bisphenol A polycarbonate (BAPC), was evaluated. BAPC was crystallized by exposure to diphenylpropane, a component of BAPC, by vapor transportation methods. Furthermore, the surface of BAPC was also crystallized by this method. Crystallized BAPC was employed as a novel simple storage medium, and bit patterns were recorded on its surface by laser irradiation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2307–2313, 2005 相似文献
992.
Kazunori Sakata Manabu Shimoda Mamoru Hashimoto 《Journal of heterocyclic chemistry》1996,33(6):1593-1598
Three new organic hosts are described that contain a tetraaza[14]annulene core to which two crown ether voids are attached. These hosts include a free base tetraaza[14]annulene and/or its complexes with benzo-15-crown-5 rings. The crown tetraaza[14]annulene is synthesized from tetraaza[14]annulene and 4′-chloroformylbenzo-15-crown-5. Its nickel(II) and copper(II) complexes are prepared in a similar manner as above. In solution the compounds do not tend to form aggregates. However, aggregation is affected by the presence of alkali-metal salts, which coordinate to the crowns. Li+ and Na+ cations with diameters that match the diameters of the crown ether rings form 1:2 host-guest complexes. Complexes with 2:2 host-guest stoichiometry are formed when the diameters of K+ and Cs+ cations exceed that of the crown ether rings. Nevertheless, it is weak for the present macrocycle and its complexes to be inclined to form dimers owing to the steric hindrance of the substituent groups and owing to restraining the rotation of the carbonyl bond connecting the crown ether group. 相似文献
993.
Recent progress in analytical terahertz (THz) spectroscopy is reviewed with illustrative examples showing that it is an effective method for detecting and identifying intermolecular interactions in chemical compounds, such as hydrogen bonds. The unique and characteristic properties of THz waves, their significance to both science and industry, and the bases of one of the successful fields of analytical THz spectroscopy, namely THz time-domain spectroscopy and THz imaging for chemical analysis, are described. Preliminary quantitative studies are presented to show the potential of THz spectroscopy for the detection and identification of intermolecular hydrogen bonds in unknown mixture samples. The selective detection of intramolecular hydrogen bonds and the detection of intramolecular interactions in ice are also introduced. Some brief remarks are provided on future developments, the main issues, and the prospects for analytical THz spectroscopy. 相似文献
994.
Teruhiko Kai Wataru Ueno Takeo Yamaguchi Shin‐Ichi Nakao 《Journal of polymer science. Part A, Polymer chemistry》2005,43(10):2068-2074
The role of vacuum ultraviolet (VUV) rays contained in the plasma during plasma‐induced graft polymerization in the pores of a porous high‐density polyethylene (HDPE) substrate was investigated through the separation of the VUV rays from the plasma with LiF, CaF2, and quartz filters. Two characteristic phenomena, the effect of the solvent on the grafting rate and the graft polymerization in the pores of the porous substrate, were observed in the VUV‐induced graft polymerization process. These results provided clear evidence that VUV rays in the plasma played an important role in the formation of grafted layers in the pores of the HDPE substrate. The relationship between the penetration depth of the VUV rays and the distribution of the grafted layer inside the substrate was examined. The calculated penetration depth of the VUV rays (and hence the distribution of radicals) and the distribution of the grafted layer were not consistent. However, this inconsistency could be explained by the fact that the effective density of the radicals that could react with the monomer to grow the grafting polymer was very low because of the steric hindrance of the grafted chains. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2068–2074, 2005 相似文献
995.
Yasuhiro Tanoue Moritsugu Hamada Norihisa Kai Kazunori Sakata Mamoru Hashimoto Takeshi Nagai 《Journal of heterocyclic chemistry》2005,42(6):1195-1199
The usefulness of 3‐iodoindoles available for introduction of an indole unit is presented. The reaction of various halo‐3‐iodoindoles with 1,4‐naphthoquinone gave the corresponding 2‐(3‐indolyl)‐1‐4,naphthoquinones in moderate yields. The 3‐iodoindole was used for synthesis of a compound containing both naph‐thazarin and indole skeletons. 相似文献
996.
Masako Fujiwara Kazunori Arifuku Itiro Ando Tadashi Nemoto 《Analytical sciences》2005,21(11):1259-1262
Urine samples were collected during the daytime and nighttime from spontaneously hypertensive model rats and normal rats without dosing. The 1H NMR spectra were measured for their urine samples, and analyzed by a pattern recognition method, known as Principal Component Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA). The separation of urinary data due to the diurnal variation (daytime and nighttime) and also to the difference between the two strains of rat was achieved in the PCA score plot. Differences of the urinary profiles in the respective separation were effectively extracted as marker variables by the SIMCA method. NMR measurements coupled with pattern recognition methods provide a straightforward approach to inspect the disease metabolic status and the preliminary screening tool of marker candidates for further development. 相似文献
997.
The discovery stories of three fluorine-containing insecticides in our laboratory are described, i.e. amidoflumet, a new trifluoromethanesulfonanilide with high miticidal activity against various house dust mites, Metofluthrin, a potent new fluorinated pyrethroid with extremely high knockdown activity against various mosquitoes, and a new α-pyrone compound, 3-[1R-trans-(2-trifluoromethyl)cyclopropanecarbonyl]-4-hydroxy-6-methyl-2-pyrone with outstanding insecticidal activity against Blattella germanica. 相似文献
998.
S.J. Chua S. Tripathy P. Chen E. Takasuka M. Ueno 《Physica E: Low-dimensional Systems and Nanostructures》2005,25(4):356-365
Using near-field scanning optical microscopy (NSOM), we report the spatial distribution of photoluminescence (PL) intensity in III-nitride-based semiconductor layers grown on GaN substrates. Undoped GaN, In0.11Ga0.89N, and In0.13Ga0.87N/GaN multi-quantum wells (MQWs) were grown by metal organic chemical vapor deposition (MOCVD) on freestanding GaN substrates. Micro-Raman spectroscopy has been used to evaluate the crystalline properties of the GaN homoepitaxial layers. The variation of the PL intensity from the NSOM imaging indicates that the external PL efficiency fluctuates from 20% to 40% in the 200 nm InGaN single layer on freestanding GaN, whereas it fluctuates from 20% to 60% in InGaN/GaN MQWs. In the NSOM-PL images, bright island-like features are observed. After deconvolution with the spatial resolution of the NSOM, the size of these features is estimated to be in the range of 150–250 nm. 相似文献
999.
Noriaki Tsurumachi Chang-Sik Son Tae Geun Kim Kazunori Hikosaka Kazuhiro Komori Mutsuo Ogura 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):300
We investigated the temperature dependence of the time-resolved photoluminescence (PL) spectra of high-density InGaAs/AlGaAs quantum wire (QWR) distributed-feedback laser structure on a submicron grating. A red-shift of peak in the time-resolved PL after photo-excitation was observed due to the relaxation of the photo-generated excitons from the entire QWR to localized centers at 10 K. On the other hand, at 60 K, no red-shift in the time-resolved PL spectra was observed since the localization centers are thermally activated and the excitons are delocalized. 相似文献
1000.
A polymer microchannel chip with a symmetrical or unsymmetrical zigzag-side-walled structure was fabricated by an imprinting method, and applied to study shape effects on solution flow characteristics as well as on the liquid/liquid extraction efficiency of an aluminium(III) chelate complex (Al-DHAB: DHAB = o,o'-dihydroxyazobenzene) in a microchannel chip. In an unsymmetrical zigzag-side-walled channel chip (us-channel), an oil/water interface was sinusoidal, while that in a symmetrical zigzag-side-walled channel chip (s-channel) was flat as long as the observation was made under an optical microscope. It was demonstrated that the efficiency of the water-to-oil (1-butanol) extraction of Al-DHAB in the microchannel was governed by the contact time between the two phases. As the most important results, furthermore, the extraction efficiency was higher in the us-channel, as compared with that in the s-channel, owing to the sinusoidal liquid/liquid interfacial structure and, therefore, to the high interfacial area between the two phases. 相似文献