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71.
Kinzo Ishikawa Keizo Miyasaka Masahiko Maeda 《Journal of Polymer Science.Polymer Physics》1969,7(12):2029-2041
Drawing of single-crystal mats of linear polyethylene has been investigated. Drawing is possible at temperatures higher than about 90°C. The drawing is accompanied by distinct necking, with a large decrease in the thickness of the mat and a very high maximum draw ratio, sometimes over 30. The maximum draw ratio is approximately proportional to the thickness of the lamellae. This behavior strongly suggests the unfolding of chains during drawing. A change of orientation of crystal axes occurs before necking without change of lamellar orientation. The a axis orients in the drawing direction; the b axis orients perpendicular to the direction of drawing; and the chain axis tilts away from the thickness direction of the mat. The structure of films drawn from mats is characterized by a distinct double orientation of crystals. This biaxial orientation in the drawn films has a high degree of correlation with the orientation of crystal axes observed before necking, and suggests that necking takes place in such a way that the chain tilts gradually about the b axis and ultimately unfolds. The postulate of formation of transitory two-dimensional crystals in necking seems useful in explaining the double orientation in the drawn film. The orientation behavior of crystal axes observed before necking is not always similar to that observed in the deformation of a single crystal. The difference is thought to be due to the effect of forces induced by drawing that act in the direction normal to the lamellae within a mat. 相似文献
72.
Yutaka Sawada Junji Yamaguchi Osamu Sakurai Keizo Uematsu Nobuyasu Mizutani Masanori Kato 《Thermochimica Acta》1979
Isothermal and non-isothermal decomposition of hydromagnesite 4 MgCO3 · Mg(OH)2 · 4 H2O was studied thermogravimetrically. Decarbonation was strongly influenced by the partial pressure of carbon dioxide. Decarbonation in an argon atmosphere proceeded via an amorphous lower carbonate to MgO. Decarbonation in a carbon dioxide atmosphere was interrupted at ~460–480°C. This interruption was explained by the formation of a metastable intermediate and the subsequent crystallization of MgCO3, both from the amorphous lower carbonate. This explanation was supported by DTA and power X-ray diffraction analysis of the quenched specimens. 相似文献
73.
A new optical system which can efficiently generate the nearly diffraction-free beams is proposed and its characteristics are investigated by numerical analysis. This optical system consists of a new optical element called a DCC (double-concave-cone) lens and an objective lens with a large numerical aperture, and can generate the Bessel beam and also the Bessel-Gauss beam. The maximum propagation distance of nearly diffraction-free beams generated by the system agrees with its theoretical value for the Bessel beam. 相似文献
74.
Takuya MatsumotoTsuyoshi Kominami Kazumasa UedaToyonari Sugimoto Toshiji TadaHarukazu Yoshino Keizo MurataMotoo Shiro Ei-ichi NegishiHiroshi Matsui Naoki Toyota Satoshi EndoKazuko Takahashi 《Journal of solid state chemistry》2002,168(2):408-417
By the reaction of a new donor molecule, ethylenedithiotetrathiafulvalenoquinone-1,3-dithiolemethide (1) with FeBr3, GaBr3 or FeCl3 in CH3CN/CS2 charge transfer (CT) salts of 1 with counteranions of FeBr4−, GaBr4− or FeCl4− (12·FeBr4, 12·GaBr4 and 12·FeCl4) as plate crystals were obtained. Their crystal structures are apparently similar to each other, in which 1 molecules are dimerized in the parallel direction of their molecular long axes, and the dimers are stacked with changing the direction of the molecular long axes alternately to form a one- dimensional column. The counteranions intervene between the 1-stacked columns and are aligned in a zigzag manner. The room-temperature electrical conductivities of 12·FeBr4 and 12·GaBr4 are fairly high (10-15 S cm−1), but a small value (0.8 S cm−1) is obtained for 12·FeCl4. For all CT salts, temperature dependences of electrical conductivity are semiconducting in spite of very small activation energies (30-90 meV). Based on the comparison between their electrical conducting and magnetic properties, it is suggested that the d spins of FeBr4− or FeCl4− ions exert almost no influence on the π conducting electrons in the 1-stacked column. 相似文献
75.
Hasegawa C Kumazawa T Uchigasaki S Lee XP Sato K Terada M Kurosaki K 《Analytical and bioanalytical chemistry》2011,401(7):2215-2223
Dextromethorphan was extracted from human plasma samples (100 μL) using MonoTip C18 tips, which are packed with C18-bonded monolithic silica gel that is attached to the inside of the tip. The samples, which contained dextromethorphan and
trimeprazine as an internal standard (IS), were mixed with 200 μL of distilled water and 50 μL of 1 mol/L glycine–sodium hydroxide
buffer (pH 10). The mixture was extracted to the C18 phase of the tip by 20 sequential aspirating/dispensing cycles using a manual micropipettor. The analytes retained on the
C18 phase were then eluted with methanol by five sequential aspirating/dispensing cycles. The eluate was injected directly into
a gas chromatograph and detected by a mass spectrometer with selected ion monitoring in positive electron ionization mode.
An Equity-5 fused silica capillary column (30 m × 0.32 mm i.d., film thickness 0.5 μm) gave adequate separation of the dextromethorphan,
IS, and impurities. The recoveries of dextromethorphan and the IS spiked into plasma were >87.4%. The regression equation
for dextromethorphan showed excellent linearity from 2.5 to 320 ng/mL of plasma, and the limit of detection was 1.25 ng/mL
of plasma. The intraday and interday coefficients of variation were less than 10.5% and 14.7%, respectively. The accuracy
ranged from 91.9% to 107%. The validated method was successfully used to quantify the plasma concentration of dextromethorphan
in a human subject after oral administration of the drug. 相似文献
76.
Keizo Fujimoto 《Journal of computational physics》2011,230(23):8508-8526
A new electromagnetic particle-in-cell (EMPIC) model with adaptive mesh refinement (AMR) has been developed to achieve high-performance parallel computation in distributed memory system. For minimizing the amount and frequency of inter-processor communications, the present study uses the staggering grid scheme with the charge conservation method, which consists only of the local operations. However, the scheme provides no numerical damping for electromagnetic waves regardless of the wavenumber, which results in significant noise in the refinement region that eventually covers over physical signals. In order to suppress the electromagnetic noise, the present study introduces a smoothing method which gives numerical damping preferentially for short wavelength modes. The test simulations show that only a weak smoothing results in drastic reduction in the noise, so that the implementation of the AMR is possible in the staggering grid scheme. The computational load balance among the processors is maintained by a new method termed the adaptive block technique for the domain decomposition parallelization. The adaptive block technique controls the subdomain (block) structure dynamically associated with the system evolution, such that all the blocks have almost the same number of particles. The performance of the present code is evaluated for the simulations of the current sheet evolution. The test simulations demonstrate that the usage of the adaptive block technique as well as the staggering grid scheme enhances significantly the parallel efficiency of the AMR-EMPIC model. 相似文献
77.
Generalizing the theorem for Goursat flags, we will characterize those flags which are obtained by “rank 1 prolongation” from the space of 1 jets for 1 independent and m dependent variables. 相似文献
78.
Nozomu Tsuboi Takanobu Hoshino Tomonori Suzuki Keizo Kato Futao Kaneko 《Journal of Physics and Chemistry of Solids》2005,66(11):2134-2138
Delafossite-type oxides of CuTbyY1−yO2, CuEuyY1−yO2, CuCaxTbyY1−x−yO2 and CuCaxEuyY1−x−yO2 have been prepared by solid state reactions. The lattice-parameter dependence on the composition implies substitution of the Tb3+, Eu3+ and Ca2+ cations for the Y3+ site. Noticeable sharp emission lines due to the f-f transitions (5D4→7FJ, J=3-6) of Tb3+ or due to the f-f transitions (5D0→7FJ, J=0-4) of Eu3+ are observed at room temperature. Electrical conductivities of CuCaxTbyY1−x−yO2 and CuCaxEuyY1−x−yO2 are larger than those of CuTbyY1−yO2 and CuEuyY1−yO2, indicating the increase of the hole concentration caused by the substitution of Ca2+ for the Y3+ site. These results indicate the controllability of the luminescence and conductivity in CuCaxTbyY1−x−yO2 and CuCaxEuyY1−x−yO2 delafossite-type oxides by simultaneous substitution of the rare earth Tb3+ or Eu3+ cation and the Ca2+ cation for the Y3+ site. 相似文献
79.
Nishiura H Kumagai J Kashino G Okada T Tano K Watanabe M 《Photochemistry and photobiology》2012,88(2):389-397
We successfully identified the bystander effect in B16 murine melanoma cells exposed to UVA irradiation. The effect was identified based on melanogenesis following the medium transfer of the B16 cells, which had been cultured for 24 h after being exposed to UVA irradiation, to nonirradiated cells (bystander cells). Our confirmation study of the functional mechanism of bystander cells confirmed the reduced levels of mitochondrial membrane potential 1-4 h after the medium transfer. In addition, we observed increased levels of intracellular oxidation after 9-12 h, and the generation of melanin radicals, including long-lived radicals, 24 h after medium transfer. Further analysis of bystander factors revealed that the administration of EGTA treatment at the time of medium transfer led to an inhibition of melanogenesis and to neutralization of the mitochondrial membrane potential level, as well as to the restoration of intracellular oxidation levels to those of controls. The results demonstrated that the UVA irradiation bystander effect in B16 cells, as indicated by melanogenesis, was induced by the increase in intracellular oxidation due to the mitochondrial activity of calcium ions, which were among the bystander factors involved in the increase. 相似文献