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121.
W. Miyano E. Inoue M. Tsuchiya K. Ishimaru T. Kojima 《Journal of Thermal Analysis and Calorimetry》2001,64(2):459-465
DSC studies are given for polytetrahydrofurans with molecular masses equal to 650, 1400, and 2900, for their blends, and for
their cured samples. The samples were stored, annealed, and quenched to obtain the samples with different thermal histories.
Two or more endothermic peaks appear in the DSC curves for the stored samples, even for the non-blended samples. A hyperbolic
curve forced the plot of the highest melting temperature vs. the molecular mass to asymptote to about 50°C. The relationship
between the highest melting temperature and the composition for the blended samples is suitable to linear or Fox’s relation.
A peak and a shoulder appear in the DSC curves of the cured samples. As the samples are cooled at the faster rates in the
thermal treatment, the shoulder appears at the lower temperatures.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
122.
Data synchronization based on the Kuramoto model for collective synchronization and hypothesis testing based on the rank test combined with the random shuffling surrogate method are applied to finding major feature patterns of weekly nonferrous metal returns from the time series of daily spot and futures price indexes in the London Metal Exchange since 1989. Our results suggest the existence of day-of-the-week anomalies in the metal returns. We conjecture that such anomalies are large-scale manifestations of synchronously accumulated risk-aversive actions of individual market players. 相似文献
123.
Kazutaka Shimbo Shintaro Kubo Yushi Harada Takashi Oonuki Takefumi Yokokura Hiroo Yoshida Michiko Amao Mina Nakamura Naoko Kageyama Junko Yamazaki Shin‐ichi Ozawa Kazuo Hirayama Toshihiko Ando Junkichi Miura Hiroshi Miyano 《Biomedical chromatography : BMC》2010,24(7):683-691
An automated method for high‐throughput amino acid analysis, using precolumn derivatization high‐performance liquid chromatography/electrospray mass spectrometry (HPLC/ESI‐MS), was developed and evaluated. The precolumn derivatization step was performed in the reaction port of a home‐built auto‐sampler system. Amino acids were derivatized with 3‐aminopyridyl‐N‐hydroxysuccinimidyl carbamate, and a 3 μm Wakosil‐II 3C8‐100HG column (100 × 2.1 mm i.d.) was used for separation. To achieve a 13 min cycle for each sample, the derivatization and separation steps were performed in parallel. The results of the method evaluation, including the linearity, and the intra‐ and inter‐precision, were sufficient to measure physiological amino acids in human plasma samples. The relative standard deviations of typical amino acids in actual human plasma samples were below 10%. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
124.
Shuji Hasegawa Xiao Tong Sakura Takeda Norio Sato Tadaaki Nagao 《Progress in Surface Science》1999,60(5-8):89-257
By utilizing a variety of surface superstructures formed on silicon surfaces and atomic layers grown on them, close correlations between the atomic-scale structures and electrical conduction phenomena at the surfaces have been revealed. State-of-art techniques for analyzing and controlling atomic/electronic structures of surfaces are leading to an understanding of the novel electronic transport properties at surfaces. For example, the electrical conduction through surface-state bands, which are inherent in the surface superstructure, has been confirmed in in-situ measurements. An important phenomenon has also been found, where adatoms donate carriers into the surface-state band, resulting in a remarkable enhancement in electrical conductance. The nucleation of the adatoms diminishes such a doping effect. Furthermore, electrical conduction through atomic layers grown on the surfaces, whose growth structures are sensitive to the substrate surface structures, will be also discussed. In this review, we emphasize that the surface electronic transport properties are closely related to the atomic structures and atomistic dynamics on surfaces. The ultimate two-dimensional electron systems, consisting of the surface-state bands and grown atomic layers, are expected to provide a new stage in surface physics, as well as a precursory stage leading to atomic-scale electronics devices. 相似文献
125.
Polar states are realized in pseudocubic manganite films fabricated on high-index substrates, in which a Jahn-Teller (JT) distortion remains an active variable. Several types of orbital orders (OOs) were found to develop large optical second harmonics, signaling broken-inversion symmetry distinct from their bulk forms and films on (100) substrates. The observed symmetry lifting and first-principles calculation both indicate that the modified JT q2 mode drives Mn-site off centering, which can be controlled by a magnetic-field-induced phase transition via a coupling of OO and spin orders. 相似文献
126.
A series of novel bisthiacalix[4]arenes with diimine linkages of different aromatic or heteroaromatic dialdehydes have been synthesized. The structure of one of the bisthiacalixarene has been analyzed by X-ray crystallography. These molecules quantitatively extract silver ion from aqueous into organic phase under neutral conditions. 相似文献
127.
The basic study on the determination of tetrafluoroborate ion (BF4−) by ion chromatography, and total boron by conversion of boric acid to BF4− followed by ion chromatography of BF4− has been carried out. The results of thermodynamic calculations for the system of boric acid (H3BO3)-F−-H+ showed that the mole fraction of BF4− was higher than 99% at pH lower than 3.5 and 4.5 when the total free fluoride concentration (2[H2F2] + 2[HF2−] + [HF] + [F−]) was as high as 0.1 and 1.0 M, respectively. The fraction of BF4− increased with increasing total free fluoride concentration. BF4− fraction values were higher than 99% at pH 0.75 and at total free fluoride concentration of 0.05 M or higher. BF4− was hardly formed at pH > 7 even when the total free fluoride concentration was as high as 1.0 M. According to the experimental results, the fraction of BF4− at pH 0.7-0.8 was 51.2, 95.6 and 96.7% when the total fluoride concentration (2[H2F2] + 2[HF2−] + [HF] + [F−] + 3[BF3OH−] + 4[BF4−]) was 0.2, 1.0 and 3.3 M, respectively. The formation reaction of BF4− from boric acid reached an equilibrium state within 20 min regardless of reaction temperature, in the range of 20-50 °C, when the total boron and total fluoride concentrations were 66.7 mM and 1.0 M, respectively. Although BF4− was formed only under acidic conditions, BF4−, once formed, was very stable under alkaline conditions at least for several hours. We have concluded that BF4− could be analyzed by ion chromatography using sodium hydroxide solution as an eluent because BF4− was stable under chromatographic conditions. BF4− solution prepared from boric acid could be used as a standard solution in the ion chromatographic analysis of BF4− instead of the sodium tetrafluoroborate (NaBF4) reagent available commercially, if a discrepancy of about 4-5% was allowed. 相似文献
128.
Surface plasmon resonance (SPR) sensor chip is proposed for magnetic field monitoring in the infrared wavelength region. The structure is based on silicon substrate and gold as SPR-active metal used with an appropriate magnetic fluid film. The angular interrogation method has been used to study the sensor’s performance in terms of large shift and small width of the SPR curve for a wide range of magnetic field between 30 and 220 Oe. The effect of field incidence angle is also studied on the proposed sensor’s performance, and it is observed that the field should be incident as parallel to the magnetic fluid surface as possible. Any possibility of oxidation problem to the proposed SPR sensor is addressed by using a stable buffer layer. All the performance parameters were found to be significantly large for the above field incidence condition. The proposed sensor is able to achieve a resolution of the order as high as 0.18 Oe for magnetic field detection. 相似文献
129.
Wakabayashi Y Bizen D Nakao H Murakami Y Nakamura M Ogimoto Y Miyano K Sawa H 《Physical review letters》2006,96(1):017202
A novel structure of orbital ordering is found in a Nd0.5Sr0.5MnO3 thin film, which exhibits a clear first-order transition, by synchrotron x-ray diffraction measurements. Lattice parameters vary drastically at the metal-insulator transition at 170 K (= T(MI)), and superlattice reflections appear below 140 K (= T(CO)). The electronic structure between T(MI) and T(CO) is identified as A-type antiferromagnetic with a d(x2-y2) ferro-orbital ordering. The new type of antiferro-orbital ordering characterized by the wave vector (1/4 1/4 1/2) in cubic notation emerges below T(CO). The accommodation of the large lattice distortion at the first-order phase transition and the appearance of the novel orbital ordering are brought about by the anisotropy in the substrate, a new parameter for the phase control. 相似文献
130.
Resonant scattering from dielectric bispheres in the specular direction (the so-called specular resonance), previously known only in the microwave range, has been observed at the optical wavelength. Systematic experiments with micrometer-sized dielectric bispheres assembled by micromanipulation, together with rigorous numerical calculations, reveal that this scattering is a precursor of the classical rainbow and is a general phenomenon observed in the wide range of size parameters (>5 for n=1.59) for various refractive indices. 相似文献