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91.
A number of hexagonal phases with inflated/deflated a lattice parameters but equal c parameters are found to exist with compositions close to that of the icosahedral phase. Surprisingly, no cubic or orthorhombic approximants are found. The closeness of the hexagonal phases to the icosahedral phase is shown through the electron diffraction features. Through stereographic analysis of the hexagonal phases it is shown that they consist of three icosahedral units rotated by 120 degrees about a common twofold axis, forming the sixfold axis. It is suggested that this phase falls into a class of crystals closely related to both the icosahedral and decagonal quasicrystals, but are not approximants to them. These phases can instead be considered to be approximant to the hexagonal quasicrystal. 相似文献
92.
Stefan Hollands Akihiro Ishibashi Robert M. Wald 《Communications in Mathematical Physics》2007,271(3):699-722
A key result in the proof of black hole uniqueness in 4-dimensions is that a stationary black hole that is “rotating”—i.e.,
is such that the stationary Killing field is not everywhere normal to the horizon—must be axisymmetric. The proof of this
result in 4-dimensions relies on the fact that the orbits of the stationary Killing field on the horizon have the property
that they must return to the same null geodesic generator of the horizon after a certain period, P. This latter property follows, in turn, from the fact that the cross-sections of the horizon are two-dimensional spheres.
However, in spacetimes of dimension greater than 4, it is no longer true that the orbits of the stationary Killing field on
the horizon must return to the same null geodesic generator. In this paper, we prove that, nevertheless, a higher dimensional
stationary black hole that is rotating must be axisymmetric. No assumptions are made concerning the topology of the horizon
cross-sections other than that they are compact. However, we assume that the horizon is non-degenerate and, as in the 4-dimensional
proof, that the spacetime is analytic. 相似文献
93.
94.
We show that the Nomura algebra of the nonsymmetric Hadamard model coincides with the Bose–Mesner algebra of the directed Hadamard graph. 相似文献
95.
96.
Akihiro Furuta 《Tetrahedron letters》2008,49(1):110-113
A combination of a catalyst derived from ferrous acetate and sodium thiophene-2-carboxylate efficiently promoted hydrosilylation of aromatic and aliphatic ketones to give the corresponding secondary alcohols in high yields with extremely high selectivity. 相似文献
97.
98.
Akihiro Tohsaki 《Frontiers of Physics》2011,6(3):320-336
We explain how to treat a microscopic wave function of ??-condensation taking a 3??-nucleus as a typical example. The wave function has been originally proposed ten years before by Horiuchi, R?pke, Schuck and the present author (Phys. Rev. Lett., 2001, 87: 192501). The microscopic model, which fully takes into account the Pauli principle between all the constituent nucleons, effective internucleon forces and the Coulomb force, can play an important role in reproducing an ??-gas nature thanks to ??-condensation as an excited state of ??-like nuclei. An essential point of the wave function is to describe their ground state simultaneously. We study its typical features by giving an analytical formula of the norm kernel and the kernel concerning the one-body operator for 3??-condensation. 相似文献
99.
The uniqueness of a binary doubly-even self-dual [48, 24, 12] code is used to prove that a self-orthogonal 5-(48, 12, 8) design, as well as some of its derived and residual designs, including a quasi-symmetric 2-(45, 9, 8) design, are all unique up to isomorphism.Received November 5, 2003 相似文献
100.
Renhua Qiu Guoping Zhang Xinhua Xu Kangbin Zou Lingling Shao Dawei Fang Yinhui Li Akihiro Orita Ryosuke Saijo Hidetaka Mineyama Tomoyoshi Suenobu Shunichi Fukuzumi Delie An Junzo Otera 《Journal of organometallic chemistry》2009,694(9-10):1524-1528
Zirconocene and titanocene bis(perfluorooctanesulfonate)s were synthesized. In contrast to the corresponding triflates and perchlorates, these compounds are air- and water-stable. They were proved to be ionic on the basis of conductivity measurements and X-ray analysis, allowing these complexes to be stored for months. The strong Lewis acidity of these cationic metallocene species, which was proved by ESR study, enabled catalytic glycosylation. 相似文献