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521.
Our theory is useful for establishing the convergence of a crystalline algorithm as well as for justifying the crystalline
flow as a limit of anisotropic curvature flow with smooth interfacial energy.
Accepted March 29, 2001?Published online September 3, 2001 相似文献
522.
Takanori Shibata Shiho Yoshida Yoshikazu Arai Maiko Otsuka Kohei Endo 《Tetrahedron》2008,64(5):821-830
A chiral iridium complex catalyzed a consecutive and enantioselective [2+2+2] cycloaddition of polyynes to give axially chiral compounds. Intermolecular reaction of tetraynes, possessing aryl groups on their termini, with protected but-2-yne-1,4-diols gave C2-symmetrical quateraryl compounds. Intramolecular reaction of hexaynes, possessing aryl or alkyl groups on their termini gave C2-symmetrical biaryl compounds. The catalytic synthesis of a pentacene derivative with axial chiralities is also discussed. 相似文献
523.
Mugio Nishizawa Tomoaki Iyenaga Hirofumi Yamamoto Kosuke Namba Yoshikazu Shizuri Yoshihide Matsuo 《Tetrahedron letters》2007,48(24):4229-4233
Total synthesis of (±)-thallusin was achieved using Hg(OTf)2·PhNMe2-induced olefin cyclization, and Suzuki coupling with a pyridylboronic acid derivative. Hg(OTf)2 also acted as a catalyst to isomerize the double bond into the more thermodynamically stable isomer when treated in toluene. Synthetic (±)-thallusin as well as an analogue showed morphogenesis-inducing activity. 相似文献
524.
Hideki Jona Jun Shibata Masanori Asai Yasuhiro Goto Sachie Arai Shigeru Nakajima Osamu Okamoto Hiroshi Kawamoto Yoshikazu Iwasawa 《Tetrahedron: Asymmetry》2009,20(21):2439-2446
An efficient and practical asymmetric synthesis of 1-tert-butyl 3-methyl (3R,4R)-4-(2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)piperidine-1,3-dicarboxylate 1, a useful intermediate for the synthesis of nociceptin antagonists, has been developed. This method includes the following key steps: (1) diastereoselective reduction of a chiral enaminoester 3 having (R)-1-phenylethylamine as a chiral pool constituent with the use of a combined TFA–NaBH4 reduction system and (2) efficient isomerization from 3,4-cis-substituted piperidine 8 to 3,4-trans-substituted piperidine 1 under basic conditions. The above methods proved to be applicable for large-scale operation and hundred grams of enantiomerically pure compound 1 (>98% ee) was obtained. 相似文献
525.
526.
Yoshikazu Kobayashi 《Journal of Mathematical Analysis and Applications》2008,338(2):852-872
A generation theorem of semigroups of locally Lipschitz operators on a subset of a real Banach space is given and applied to the problem of the well-posedness of the Carrier equation utt−κ(‖u‖2)Δu+γ|ut|p−1ut=0 in Ω×(0,∞) with acoustic boundary condition, where p>2 and Ω is a bounded domain in an arbitrary dimensional space. 相似文献
527.
We study simple cases of crystalline driven curvature flow with spatially nonuniform driving force term. We assume special
monotonicity properties of the driving term, which are motivated by our previous work on Berg’s effect. We show that initially
flat facets may begin to bend, provided, loosely speaking, they are too large.
相似文献
528.
Hitoshi Nakahara Yoshikazu Kusano Takumi Kono Yahachi Saito 《Applied Surface Science》2009,256(4):1214-1217
Brightness of carbon nanotube (CNT) emitters was already reported elsewhere. However, brightness of electron emitter is affected by a virtual source size of the emitter, which strongly depends on electron optical configuration around the emitter. In this work, I-V characteristics and brightness of a CNT emitter are measured under a practical field emission electron gun (e-gun) configuration to investigate availability of CNT for electron microscopy. As a result, it is obtained that an emission area of MWNT is smaller than its tip surface area, and the emission area corresponds to a five-membered-ring with 2nd nearest six-membered-rings on the MWNT cap surface. Reduced brightness of MWNT is measured as at least 2.6×109 A/m2 sr V. It is concluded that even a thick MWNT has enough brightness under a practical e-gun electrode configuration and suitable for electron microscopy. 相似文献
529.
Takayuki Oku Takayuki Kikuchi Takenao Shinohara Jun-ichi Suzuki Yuya Ishii Masayasu Takeda Kazuhisa Kakurai Yuji Sasaki Mikio Kishimoto Makoto Yokoyama Yoshikazu Nishihara 《Physica B: Condensed Matter》2009,404(17):2575-2577
We have performed small-angle polarized neutron scattering experiments of spherical Fe16N2 nano-particles, which are potential candidate materials for high density magnetic recording tape. The results were analyzed based on a core-shell model, and we evaluated the magnetic structure of the particles. The correlation between the magnetic structure and magnetic stability of the particles were discussed in terms of high density recordings. 相似文献
530.
K. Deguchi S. Ogawara T. Okutsu M. Nagao T. Watanabe Y. Mizuguchi Y. Kubo F. Tomioka S. Ishii S. Tsuda T. Yamaguchi M. Nagasawa Y. Takano 《Physica C: Superconductivity and its Applications》2009,469(15-20):965-966
Single-crystalline (Lu, Ca)Ba2Cu3O7−δ (Lu(Ca)123) whiskers have been successfully grown using the Te-doping method. X-ray diffraction patterns of Lu(Ca)123 whiskers showed sharp (0 0 l) peaks corresponding to REBa2Cu3O7−δ phase (RE = rare earth elements). Transport measurements showed that the superconducting transition occurred at 83 K in the obtained whiskers. 相似文献