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31.
Shirakawa S Terao SJ He R Maruoka K 《Chemical communications (Cambridge, England)》2011,47(38):10557-10559
Highly diastereo- and enantioselective conjugate addition of α-substituted nitroacetates to maleimides under base-free neutral phase-transfer conditions was developed for the synthesis of α,α-disubstituted α-amino acid derivatives. 相似文献
32.
Tsukamoto K Shinohara Y Iwasaki S Maeda H 《Chemical communications (Cambridge, England)》2011,47(17):5073-5075
For detection of Hg(2+) and Ag(+), we have developed a coumarin-based probe with an N'-acetylthioureido group as a novel fluorescence switch, in which the hydrogen bond formation between the N-hydrogen and the acetyl O atom markedly increases the susceptibility of the probe toward desulfurization by Hg(2+) and Ag(+). 相似文献
33.
Tsuchiya T Imai H Miyoshi S Glans PA Guo J Yamaguchi S 《Physical chemistry chemical physics : PCCP》2011,13(38):17013-17018
The electronic structure and modification of the local interatomic structure of a reactive sputtered amorphous tantalum oxide (a-TaO(x)) thin film with the variation of oxygen nonstoichiometry, x in a-TaO(x) have been investigated by X-ray absorption spectroscopy (XAS), X-ray photoemission spectroscopy (XPS), Raman scattering spectroscopy, and Rutherford back scattering spectroscopy. A parallel chemical shift of Ta4f(7/2) and O1s core levels observed with the variation of x indicates the Fermi level shift by reduction and oxidation in the framework of the rigid band model. Extended X-ray absorption fine structure (EXAFS) suggests both the increase of average coordination number of the first Ta-O shell in polyhedra and a considerable reduction of the average Ta-O bond length with the increase of x. The relative intensity of Raman shift peaks at 670 cm(-1) and 815 cm(-1), corresponding to Ta-O stretching of TaO(6) octahedra and TaO(5) probably with a pyramidal form, respectively, drastically changes between x = 2.47 to 1.86, suggesting the change in the predominant polyhedron from TaO(6) to TaO(5) with a modification in multiplicity of oxygen by the reorganization of the polyhedral network. 相似文献
34.
Based on the dispersionless KP (dKP) theory, we study a topological Landau-Ginzburg (LG) theory characterized by a rational
potential. Writing the dKP hierarchy in a general form treating all the primaries in an equal basis, we find that the hierarchy
naturally includes the dispersionless (continuous) limit of Toda hierarchy and its generalizations having a finite number
of primaries. Several flat solutions of the topological LG theory are obtained in this formulation, and are identified with
those discussed by Dubrovin. We explicitly construct gravitational descendants for all the primary fields. Giving a residue
formulae for the 3-point functions of the fields, we show that these 3-point functions satisfy the topological recursion relation.
The string equation is obtained as the generalized hodograph solutions of the dKP hierarchy, which show that all the gravitational
effects to the constitutive equations (2-point functions) can be renormalized into the coupling constants in the small phase
space.
Supported in part by NSF grant DMS-9403597. 相似文献
35.
36.
Shogo Tanimura 《Annals of Physics》1992,220(2)
R. P. Feynman showed F. J. Dyson a proof of the Lorentz force law and the homogeneous Maxwell equations, which the obtained starting from Newton's law of motion and the commutation relations between position and velocity for a single nonrelativistic particle. We formulate both a special relativistic and a general relativistic versions of Feynman's derivation. Especially in the general relativistic version we prove that the only possible fields that can consistently act on a quantum mechanical particle are scalar, gauge, and gravitational fields. We also extend Feynman's scheme to the case of non-Abelian gauge theory in the special relativistic context. 相似文献
37.
The processes of field ionization are considered by the time dependent perturbation theory. The metal wave function to be occupied by a tunneling electron from a monovalent atom is approximated by the tight-binding method. The system considered is hydrogen imaging a tungsten-type metal. The (001) crystallographic plane with an interatomic spacing of 3.16 Å and an externally applied electric field of 2.3 V/Å is considered for numerical results. Image formation mechanisms of field ion microscopy are qualitatively discussed. 相似文献
38.
The phase-matched second harmonic generation by periodic structures composed of laminae of nonlinear optical crystals has been studied experimentally. It is shown that the intensity of the second harmonic is approximately proportional to the square of the number of laminae under phase-matched condition, which is satisfied over a broad frequency range by the variation of the angle of incidence when a laminar structure with a period much larger than the coherence length is used. 相似文献
39.
Hiroki Kanda Brian Beckford Takeji Fujibayashi Takao Fujii Yu Fujii Kenta Futatsukawa Toshiyuki Gogami Yun-Cheng Han Osamu Hashimoto Kentaro Hirose Ryotaro Honda Kenji Hosomi Alan Iguchi Takatsugu Ishikawa Yusuke Kaneko Masashi Kaneta Yuma Kasai Daisuke Kawama Taito Kawasaki Chigusa Kimura Shogo Kiyokawa Takeshi Koike Kazushige Maeda Tomofumi Maruta Nayuta Maruyama Masao Matsubara Koji Miwa Yohei Miyagi Sho Nagao Satoshi N. Nakamura Akira Okuyama Kotaku Suzuki Tadaaki Tamae Hirokazu Tamura Nobuhiro Terada Kyo Tsukada Tie-Shang Wang Fumiya Yamamoto Takeshi O. Yamamoto Hirohito Yamazaki 《Few-Body Systems》2013,54(7-10):1175-1178
Photoproduction of the neutral kaon on the deuteron has been investigated at the Research Center for Electron Photon Science, Tohoku University. We constructed the Neutral Kaon Spectrometer-2 for the detection of charged particles from the decay of the neutral kaon and the hyperon. We obtained a momentum distribution of K 0 with the inclusive measurement. It was consistent with the previous measurement. The total cross section of γ + d → K 0 + Λ + p was estimated from the measured integral cross section of γ + d → Λ + X. The total cross section with respect to the photon energy was compared with the theoretical calculations. It favored the Saclay-Lyon A model calculation with the ratio of the neutral to charged coupling constants of the axial-vector meson, K 1, as ~ ?1.5. The energy dependence and the magnitude of the total cross section were similar to the total cross section of γ + p → K + Λ. 相似文献
40.
Shogo Morisako Seiya Watanabe Satoru Ikemoto Satoshi Muratsugu Mizuki Tada Makoto Yamashita 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15173-15177
A pincer‐iridium complex bearing a Lewis‐base‐free X‐type alumanyl ligand has been synthesized. X‐ray diffraction, NMR and IR spectroscopy, as well as XANES analysis confirmed its tetrahydrido‐IrV structure and Lewis acidity at the Al center as supported by DFT calculations. The resulting complex was applied as a catalyst for the transfer dehydrogenation of cyclooctane. 相似文献