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991.
Keiji Konno Nobuo Deguchi Koichiro Yonetake Mitsuru Ueda Patrick E. Cassidy John W. Fitch 《Journal of polymer science. Part A, Polymer chemistry》1997,35(4):605-611
Poly(arylene ether)s ( 3 ) containing pendant benzoyl groups were prepared by the aromatic substitution reaction of 2,5-difluoro-4-benzoylbenzophenone (2) with hydroquinone ( 1a ) and methylhydroquinone ( 1b ) in the presence of potassium carbonate in N,N-dimethylacetamide. The polycondensation proceeded smoothly at 165°C and produced poly(arylene ether)s with inherent viscosities up to 0.8 dL/g. The polymer ( 3b ) derived from methylhydroquinone was quite soluble in common organic solvents and could be processed into uniform films from solutions. On the other hand, the polymer ( 3a ) derived from hydroquinone was only soluble in pentafluorophenol and methanesulfonic acid and had a high crystallinity. These polymers showed 10% weight losses at around 420 and 490°C in nitrogen. Polymer 3b also showed good tensile strength and tensile moduli. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 605–611, 1997 相似文献
992.
Nagasawa T. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2001,29(4):569-572
Reflex klystron electron oscillation, occurring in a plasma potential well formed in a system consisting of plasma and two electrodes (filaments and a mesh grid which is at floating potential), was observed in a very simple device with only filaments and a mesh grid. This oscillation mechanism consists of three elements: 1) an acceleration region on the side in which filaments are located, which accelerates primary electron beams emitted from filaments; 2) a deceleration region on the side in which the mesh grid is located, which causes the reflection of the beams; and 3) a plasma region. In addition, the velocity modulation of primary electron beams is given by the electron plasma oscillation at the presheath on the filament side. The maximum amplitude and frequency of an oscillation obtained by this mechanism were Vpp=210 mV 210 mV and f=200 MHz, respectively. These values can be controlled by the discharge potential 相似文献
993.
Kikuchi H. Nagasawa H. Mekata M. Fudamoto Y. Kojima K.M. Luke G.M. Uemura Y.J. Mamiya H. Naka T. 《Hyperfine Interactions》1999,120(1-8):623-627
AgNiO2, a model compound of an S=1/2 triangular lattice, was studied by muon spin relaxation in addition to ac, dc susceptibility,
electrical resistivity and neutron diffraction. The relaxation rate shows a sharp peak at around TN=28 K followed by a sudden decrease of initial asymmetry indicating a magnetic ordering. Three internal fields ranging from
0.2 to 0.3 T were obtained from the muon precession period. However, a neutron diffraction experiment failed to detect any
magnetic order at low temperatures. From these results, it was concluded that magnetic coherence is confined to small domain
compared with the coherence length of neutron diffraction due to spin frustration.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
994.
Yukio Furukawa Shinobu Furukawa Shino Maekawa Mitsuru Ishima 《Macromolecular Symposia》2002,184(1):99-106
The infrared spectra of the light-emitting diodes and the metal-insulator-semiconductor devices based on a poly(p-phenylenevinylene) derivative MEH-PPV have been measured in situ with a reflection configuration. The voltage-induced infrared spectra of these devices have been measured by the FT-IR difference-spectrum method. The observed bands have been attributed to the carriers injected into the polymer layers. The observation of positive carriers in the polymer light-emitting diode is probably related to the predominance of injected positive carriers, which is one of the factors in the low efficiency of the polymer light-emitting diode. In situ infrared reflective absorption measurements provide the information about injected carriers, which play a central role in the properties and the functions of polymer electronic devices. 相似文献
995.
Akinori Nishio Amane Mochizuki Jun‐Ichi Sugiyama Kazuhiko Takeuchi Michihiko Asai Koichiro Yonetake Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2001,39(3):416-429
An ordered head‐to‐tail (HT) polyurethane was successfully prepared by the polyaddition reaction of p‐isocyanatobenzyl isocyanate with ethylene glycol with dibutyltin dilaurate as a catalyst. Furthermore, the HT regularity of polyurethane was improved to 83% with 1,1,3,3‐tetraphenyl‐1,3‐dichlorodistannoxane. The polymerization was conducted in N,N‐dimethylformamide at 30 °C with both monomers mixed at once. The microstructure of the polymer was investigated by 1H and 13C NMR spectroscopy, and the polymer obtained by the polyaddition reaction had the expected HT linkages. The constitutional regularity of the polymers influenced the thermal properties and crystallinity. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 416–429, 2001 相似文献
996.
997.
998.
Takeyuki Nagasawa Atsushi Tachikawa 《Mathematical Methods in the Applied Sciences》1996,19(16):1303-1316
The initial-boundary value problem in non-cylindrical domain for a semilinear hyperbolic system is investigated. A weak solution is constructed by the method of semidiscretization in time variable combining with variational calculus, when the time sections of domain has non-decreasing property. 相似文献
999.
Daiyu KOBAYASHI Reiko WATANABE Mitsuru YAMAMOTO Masahiro KIZAKI 《Physical Therapy Research》2020,23(2):172
Objective: This study aimed to define the efficacy and features of physical therapy (PT) using the Nintendo Wii Fit U (Nintendo Inc., Kyoto, Japan) in patients with hematological malignancies confined to a bioclean room. Method: A total of 33 patients with hematological malignancies confined to a bioclean room were enrolled in this study. This study was designed as a randomized crossover test between two weeklong interventions: PT program (Therapist PT) and Wii Fit U program (Wii PT). We compared the efficacy of Wii PT and Therapist PT with regard to physical and psychological function test scores. Results: Of the 33 patients, 22 were analyzed. The validity of the crossover design was demonstrated, as there were no significant differences in period and carryover effects between the two groups. Therapist PT resulted in significantly better improvements in fatigue scores and total mood disturbance (TMD) scores in the Profile of Mood States short-form Japanese version compared to Wii PT (fatigue score, -5.2±8.3 vs 2.7±8.2; TMD score, -22.5±32.8 vs -2.6±20.5; p<0.05). Physical function improved post-Wii PT and post-Therapist PT interventions (p<0.05), and there was no difference in treatment effect. Conclusion: Improvements in physical function were clearly observed following the use of Wii PT in patients confined to a bioclean room. However, compared to Therapist PT, Wii PT was less effective in improving the psychological function of patients. 相似文献
1000.
Dr. Takayuki Iwata Satoru Kumagai Dr. Tatsuro Yoshinaga Masato Hanada Prof. Dr. Yoshihito Shiota Prof. Dr. Kazunari Yoshizawa Prof. Dr. Mitsuru Shindo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(45):11548-11553
A Pd-catalyzed domino reaction of 1,8,13-tribromo-9-methoxytriptycenes is reported. Under conventional Suzuki coupling conditions, the triptycenes underwent multiple transformations to give 1,9-bridged triptycenes. Based on mechanistic investigations, a single Pd catalyst functions as Pd0, PdII and PdIV species to catalyze four distinct processes: (1) aryl to alkyl 1,5-Pd migration, (2) intramolecular arylation, (3) homocoupling of phenylboronic acid and (4) Suzuki coupling. DFT calculations revealed that 1,5-Pd migration likely proceeds via both concerted PdII and stepwise PdIV routes. Asymmetric synthesis of the chiral triptycenes, as well as optical resolution, and further transformation are also reported. 相似文献