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811.
Miki Wadati 《Pramana》2001,57(5-6):841-847
As an introduction to the special issue on nonlinear waves, solitons and their significance in physics are reviewed. The soliton
is the first universal concept in nonlinear science. Universality and ubiquity of the soliton concept are emphasized. 相似文献
812.
Prof. Dr. Koji Miki Takeru Noda Prof. Dr. Masayuki Gon Prof. Dr. Kazuo Tanaka Prof. Dr. Yoshiki Chujo Prof. Dr. Yoshiyuki Mizuhata Prof. Dr. Norihiro Tokitoh Prof. Dr. Kouichi Ohe 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(39):9211-9216
Carbon-based double helicates consisting of two anthracene-containing oligo(p-phenyleneethynylene) units and two flexible chiral 1,1′-binaphthyl units or two rigid chiral 9,9′-spirobifluorene units were developed. The curved oligo(p-phenyleneethynylene) fragments in the double helicates were successfully constructed by tin-mediated reductive aromatization. Helical oligo(p-phenyleneethynylene) double strands fixed by two rigid spirobifluorene units showed little structural change under photoirradiation, thereby emitting circularly polarized luminescence (CPL) in the visible region with a high quantum yield (ΦPL=0.93). In contrast, flexible binaphthyl units induced dynamic structural change of the oligo(p-phenyleneethynylene) luminophores under photoirradiation, leading to strong CPL (|glum|=1.1×10−2) in the near-infrared (NIR) region. UV/Vis, circular dichroism (CD), CPL and NMR spectroscopic analyses of the binaphthyl-hinged double helicate suggested excimer formation between two π-conjugated strands in the excited state. Theoretical calculations highlight the importance of the tightly interlocked excimer structure of the carbon-based double helicate in controlling the angle between the electric and magnetic transition dipole moments for strong NIR CPL generation. 相似文献
813.
814.
Tsutomu Ikegami Tetsuya Sakurai 《Journal of Computational and Applied Mathematics》2010,233(8):1927-1936
The Sakurai-Sugiura projection method, which solves generalized eigenvalue problems to find certain eigenvalues in a given domain, was reformulated by using the resolvent theory. A new interpretation based on filter diagonalization was given, and the corresponding filter function was derived explicitly. A block version of the method was also proposed, which enabled not only resolution of degenerated eigenvalues, but also an improvement in numerical accuracy. Three numerical examples were provided to illustrate the method. 相似文献
815.
816.
Jin Gong Yasuhide Yakushi Tetsuya Uchida Shinichi Yamazaki Kunio Kimura 《Journal of polymer science. Part A, Polymer chemistry》2011,49(1):127-137
Polymerizations of 4‐(4‐acetoxybenzylideneamino)benzoic acid were performed in dibenzyltoluene (DBT) and a mixture of DBT and liquid paraffin at 350 °C for 6 h. Fibrillar crystals of poly[4‐(4‐oxybenzylideneamino)benzoyl] (POAB) having the width of 50–450 nm and the length of over 15 μm were obtained by the crystallization during the polymerization. The fibrillar crystals possessed high crystallinity and the molecular chains aligned perpendicular to the long axis of the fibrillar crystals. Plate‐like crystals were initially formed by the crystallization of oligomers, and then they changed to the fibrillar crystals via the formation of bundle‐like crystals after 1 h. Molecular weight increased by the further polymerization in the crystals. Based on these results, one‐pot preparation of the fibrillar POAB crystals was examined by the polymerization of 4‐acetoxybenzaldehyde and 4‐aminobenzoic acid. The polymerization at 180 °C for 2 h and then at 350 °C for 6 h afforded the fibrillar crystals with a small amount of the ribbon‐like crystals. Although the side‐reaction to generate the p‐benzamide sequences was not completely depressed, the sequence of heating in which 180 °C for the formation of the azomethine linkage and then 350 °C for the formation of the ester linkage was preferable to prepare the fibrillar POAB crystals. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
817.
818.
Tomoyuki Yamamoto Taiji Kanda Yuko Nishihara Tetsuya Ooshima Yoichiro Saito 《Journal of Polymer Science.Polymer Physics》2009,47(12):1181-1191
Oxygen permeability and the free‐volume hole size (cavity size) of ethylene‐vinylalcohol copolymers (EVOH) indicate abnormal humidity dependence, that is, they have minimum values in the range of around 20–40% RH, not showing a monotonic increase with humidity. To clarify this abnormal phenomenon, we investigated its molecular mobility and amorphous structure change by means of solid‐state NMR and temperature‐modulated differential scanning calorimetry (TMDSC). The glass transition temperature (Tg) decreased with humidity. Specimens stored at 15–60% RH showed large enthalpy relaxation, and it was found that the amorphous structure became more compact and the molecular conformation became more stable by ageing within this range of humidity. Under these conditions, solid‐state NMR measurement showed a component with intermediate relaxation time in the amorphous region. The results obtained by TMDSC and solid‐state NMR showed a reduction in molecular mobility by densifying in the amorphous region under the condition of 15–60% RH. The fact that the oxygen permeability and the cavity size of EVOH indicate minimum values at low humidity are attributed to the reduction in molecular mobility by enthalpy relaxation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1181–1191, 2009 相似文献
819.
Hiroyuki Ono Yosuke Suzuki Tetsuya Kaneko Ryota Tanaka Fuminori Sato Yuhki Sato Hiromitsu Mimata Hiroki Itoh 《Biomedical chromatography : BMC》2019,33(9)
Blood concentrations of tacrolimus show large variability among patients and the narrow therapeutic range is related to adverse effects. Therefore, therapeutic drug monitoring is needed for strict management. 13‐O‐Demethyl tacrolimus (13‐O‐DMT) was reported as the major metabolite formed by cytochrome P450 (CYP)3A such as CYP3A5. In previous studies, the best lower limit of quantification (LLOQ) was 0.1 ng/mL for both substances. However, this LLOQ may not be low enough now because the dosage of tacrolimus has decreased in recent years. The purpose of this study was to develop and validate a high‐sensitivity and high‐throughput assay for simultaneous quantification of tacrolimus and 13‐O‐DMT in human whole blood using ultra‐performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS). Thirty‐five stable kidney transplant recipients receiving tacrolimus were recruited in this study. The calibration curve range was 0.04–40 ng/mL. All calibration samples and quality control samples fulfilled the requirements of the US Food and Drug Administration and the European Medicines Agency guidelines for assay validation. Trough concentrations of tacrolimus and 13‐O‐DMT in 35 stable kidney transplant recipients receiving tacrolimus were within the range of the respective calibration curve. Our novel UPLC–MS/MS method is more sensitive than previous methods for quantification of tacrolimus and 13‐O‐DMT. 相似文献
820.
We report on sensitivity control of fiber optic sensors using microbend long-period fiber gratings. By tuning the phase difference between a pair of periodically aligned rod arrays that sandwiches a single-mode fiber, we can change the coupling strength of the core mode with radiating cladding modes, resulting in variable pressure sensitivity of the transmission power through the fiber. This technique enables control of the measurable range of pressure. When the phase difference is shifted from π toward 0, the measurable range is expanded from 1.7 to 3.3 N/cm and higher using a light-emitting diode as an input light source. 相似文献