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961.
962.
Mitsuyasu Yatsuzuka Kikoh Satoh Sadao Nobuhara Kiyoshi Yatsui Masahiro Yokoyama 《Physics letters. A》1983,95(6):293-296
Parametric excitation of the drift wave is observed by an ion beam modulated near the lower-hybrid frequency. An rf field parallel to the magnetic field is found to play an important role in the excitation of the instability. Substantial increase of the ion and electron temperatures is observed. 相似文献
963.
Treatment of (Z)-trimethylsilyl enol ethers with dibutylboryl trifluoromethanesulfonate followed by removal of trimethylsilyl triflate generated and addition of aldehydes affords the corresponding erythro aldols with almost complete stereo- and regio-selectivities. 相似文献
964.
Tadahiko Tsushima Junko Nishikawa Tomohiro Sato Hiroshi Tanida Kazuo Tori Teruji Tsuji Susumu Misaki Masahiro Suefuji 《Tetrahedron letters》1980,21(37):3593-3594
Reductive amination of 3-fluorophenylpyruvic acid was found to give erythro-3-fluorophenylalanine with high selectivity. 相似文献
965.
Masahiro Hasegawa Kunio Arai Shozaburo Saito 《Journal of polymer science. Part A, Polymer chemistry》1987,25(11):3117-3125
The encapsulation of inorganic powder of submicron sizes was attempted with soapless emulsion polymerization of methyl methacrylate in water in the presence of the powder. The powders used were barium sulfate and calcium carbonate. The polymerizations were initiated by potassium persulfate and by sodium bisulfite-oxygen redox reaction. The encapsulation state of the powder with the polymer formed varied considerably with the initiators used. With potassium persulfate initiator the powder surface was partially or totally covered by polymer particles, while with redox initiator under air atmosphere the powder surface was well encapsulated with a film-like polymer layer. From the differences in the encapsulation states, an encapsulation mechanism is suggested for each initiator system. Based upon this mechanism, a new encapsulation process capable of covering uniformly fine powders with a film polymer is proposed. An important factor in the new process is the addition of an extremely small quantity of a surfactant into the reaction system prior to the polymerization. 相似文献
966.
Bungo Ochiai Masahiro Matsuki Daisuke Nagai Toyoharu Miyagawa Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2005,43(3):584-592
Radical polymerization behavior of a vinyl substituted cyclic carbonate, 4‐phenyl‐5‐vinyl‐1,3‐dioxoran‐2‐one ( 1 ), is described. Radical polymerization of 1 proceeded through selective vinyl polymerization to produce polymers bearing carbonate groups in the side chain, in contrast to that of an oxirane analogue of 1 , 1‐phenyl‐2‐vinyl oxirane that proceeds via the selective ring‐opening fashion. Although the homopolymerization of 1 produce polymers in relatively lower yield, copolymerizations effectively provided cyclic carbonate‐containing copolymers. Nucleophilic addition of primary amines to the resulting homopolymers and copolymers produced the corresponding multifunctional polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 584–592, 2005 相似文献
967.
Masahiro Nakagawa 《Liquid crystals》1990,8(5):651-675
On the basis of the symmetry consideration of the Sc* phase, a generalized elastic free energy of ferroelectric Sc* liquid crystals is presented to account for the layer compression or dilatation and the layer distortion as well as c director deformation. The present elastic free energy is expressed in terms of three vectors, i.e. the c director and the wave vector and the spontaneous polarization vector. According to the present Sc* model with C2 symmetry, it is shown that there may exist 17 non-chiral, 4 chiral terms and 14 flexoelectric terms in the Sc* phase. A few practical applications are also presented to elucidate some interesting elastic properties of Sc* (or Sc) in simplifed geometries. 相似文献
968.
969.
Multimetal‐Substituted Epsilon‐Iron Oxide ϵ‐Ga0.31Ti0.05Co0.05Fe1.59O3 for Next‐Generation Magnetic Recording Tape in the Big‐Data Era 下载免费PDF全文
Prof. Shin‐ichi Ohkoshi Dr. Asuka Namai Marie Yoshikiyo Dr. Kenta Imoto Kazunori Tamazaki Koji Matsuno Osamu Inoue Tsutomu Ide Kenji Masada Masahiro Goto Takashi Goto Takayuki Yoshida Tatsuro Miyazaki 《Angewandte Chemie (International ed. in English)》2016,55(38):11403-11406
From the viewpoints of large capacity, long‐term guarantee, and low cost, interest in magnetic recording tapes has undergone a revival as an archive storage media for big data. Herein, we prepared a new series of metal‐substituted ?‐Fe2O3, ?‐GaIII0.31TiIV0.05CoII0.05FeIII1.59O3, nanoparticles with an average size of 18 nm. Ga, Ti, and Co cations tune the magnetic properties of ?‐Fe2O3 to the specifications demanded for a magnetic recording tape. The coercive field was tuned to 2.7 kOe by introduction of single‐ion anisotropy on CoII (S=3/2) along the c‐axis. The saturation magnetization was increased by 44 % with GaIII (S=0) and TiIV (S=0) substitution through the enhancement of positive sublattice magnetizations. The magnetic tape media was fabricated using an actual production line and showed a very sharp signal response and a remarkably high signal‐to‐noise ratio compared to the currently used magnetic tape. 相似文献
970.
Zameer Shervani Yutaka Ikushima Masahiro Sato Hajime Kawanami Yukiya Hakuta Toshirou Yokoyama Takako Nagase Hironobu Kuneida Kenji Aramaki 《Colloid and polymer science》2008,286(4):403-410
We have employed a number of reducing and capping agents to obtain Ag(0) metallic nanoparticles of various sizes and morphologies.
The size and morphology were tuned by selecting reducing and capping agents. Spherical particles of 15 and 43 nm diameter
were obtained when 1 wt% aqueous starch solution of AgNO3 precursor salt was reduced by d(+)-glucose and NaOH, respectively, on heating at 70 °C for 30 min. Smaller size particles obtained in the case of d(+)-glucose reduction has been attributed to the slow reduction rate by mild reducing agent d(+)-glucose compared to strong NaOH. Conducting the reduction at ambient temperature of silver salt in liquid crystalline
pluronic P123 and L64 also gave spherical particles of 8 and 24 nm, respectively, without the addition of any separate reducing
agent. NaOH reduction of salt in ethylene glycol (11 g)/polyvinyl pyrolidone (PVP; 0.053 g) mixture produced large self-assembled
cubes of 520 nm when smaller (26–53 nm) star-shaped sharp-edged structures formed initially aggregated on heating the preparation
at 190 °C for 1 h. Increasing the amount of PVP (0.5 g) in ethylene glycol (11 g) and heating at 70 °C for 30 min yielded
a mixture of spherical and non-spherical (cubes, hexagons, pentagons, and triangle) particles without the addition of an extra
reducing agent. Addition of 5 wt% PVP to 1 wt% aqueous starched solution resulted in the formation of a mixture of spherical
and anisotropic structures when solution heated at 70 °C for 1 h. Homogeneous smaller sized (29 nm) cubes were synthesized
by NaOH reduction of AgNO3 in 12.5 wt% of water-soluble polymer poly(methyl vinyl ether) at ambient temperature in 30 min reaction time. 相似文献