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排序方式: 共有290条查询结果,搜索用时 15 毫秒
31.
Takuo Okuchi Naotaka Tomioka Narangoo Purevjav Jun Abe Stefanus Harjo Wu Gong 《高压研究》2013,33(2):273-280
Neutron powder diffraction measurements of 0.9 mm3 of mixture of deuterated brucite and pressure medium were conducted at pressures to 2.8 GPa, using an opposed anvil cell and a medium-resolution diffractometer at Japan Proton Accelerator Research Complex pulsed neutron source. Spurious-free diffraction patterns were successfully obtained and refined to provide all structural parameters including Debye–Waller factors. Tilting of hydroxyl dipoles of brucite toward one of the three nearest-neighbor oxygen anions was confirmed to be substantial at pressure as low as 1.5 GPa. By this application, technical feasibility to analyze such a small sample has been newly established, which would be useful to extend the applications of neutron diffraction at high pressures. 相似文献
32.
Hyperplane arrangements in a three-dimensional vector spaceare considered in this paper. A characterization of the freenessof such an arrangement is given in terms of the characteristicpolynomial and a restricted multiarrangement. As an application,the freeness of cones over certain two-dimensional affine arrangementsis proved. 2000 Mathematics Subject Classification 52C35 (primary),32S22 (secondary). 相似文献
33.
We numerically study quantum mechanical features of the Bunimovich stadium billiard and the rational billiards which approach the former as the number of their sides increases. The statistics of energy levels and eigenfunctions of the rational billiards becomes indistinguishable from that of the Bunimovich stadium billiard below a certain energy. This fact contradicts the classical picture in which the Bunimovich stadium billiard is chaotic, but the rational billiard is pseudointegrable. It is numerically confirmed that the wave functions do not detect the fine structure, which is much smaller than the wavelength. 相似文献
34.
We study self-propulsion of a half-metal coated colloidal particle under laser irradiation. The motion is caused by self-thermophoresis: i.e., absorption of a laser at the metal-coated side of the particle creates local temperature gradient which in turn drives the particle by thermophoresis. To clarify the mechanism, temperature distribution and a thermal slip flow field around a microscale Janus particle are measured for the first time. With measured temperature drop across the particle, the speed of self-propulsion is corroborated with the prediction based on accessible parameters. As an application for driving a micromachine, a microrotor is demonstrated. 相似文献
35.
K. Tshoo Y. Satou H. Bhang S. Choi T. Nakamura S. Deguchi Y. Kawada Y. Kondo N. Kobayashi Y. Nakayama K. N. Tanaka N. Tanaka N. Aoi M. Ishihara T. Motobayashi H. Otsu H. Sakurai S. Takeuchi Y. Togano K. Yoneda Z. H. Li F. Delaunay J. Gibelin F. M. Marques N. A. Orr T. Honda M. Matsushita T. Kobayashi Y. Miyashita T. Sumikama K. Yoshinaga S. Shimoura D. Sohler T. Zheng Z.X. Cao 《Few-Body Systems》2013,54(1-4):459-463
The unbound excited states of the most neutron-rich dripline oxygen isotope, 24O, have been investigated by using the 24O(p,p′)24O* reaction at the beam energy of 62 MeV/nucleon in inverse kinematics. The first and second unbound excited states of 24O have been observed at ${E_{\rm x}= 4.63_{-0.14}^{+0.30}}$ MeV and ${E_{\rm x}= 5.13_{-0.24}^{+0.19}}$ MeV (preliminary) along with the evidence for another higher lying state at around 7.3 MeV. The quadrupole deformation parameter ${\beta_{2^+}}$ was deduced to be ${0.15_{-0.03}^{+0.08}}$ (preliminary) for the first time. The systematics of the ${\beta_{2^+}}$ and the ${E_{\rm x}(2_1^+)}$ in the Z = 8 isotopes shows the N = 16 spherical shell closure in 24O. 相似文献
36.
Hideyuki Toyota Tomonori Sasaki Yoshio Jinbo Naotaka Uchitomi 《Journal of Crystal Growth》2008,310(1):78-82
GaSb/AlGaSb multi-quantum well (MQW) structures with an AlSb initiation layer and a relatively thick GaSb buffer layer grown on Si (0 0 1) substrates were prepared by molecular beam epitaxy (MBE). Transmission electron microscopy (TEM) images and high-resolution X-ray diffraction (XRD) patterns indicated definite MQW structures. The photoluminescence (PL) emission around 1.55 μm wavelength was observed for 10.34 nm GaSb/30 nm Al0.6Ga0.4Sb MQW structure at room temperature. Dependence of PL emission energy on GaSb well width was well explained by finite square well potential model. 相似文献
37.
38.
Yukako Yoshinaga Dr. Takeshi Yamamoto Prof. Dr. Michinori Suginome 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(18):7318-7322
Enantiospecific intramolecular Suzuki–Miyaura-type coupling with α-(2-halobenzoylamino)benzylboronic esters to give 3-substituted isoindolinones is achieved by using copper catalysts with 2,2′-bipyridine-based achiral ligands. Enantioenriched α-aminobenzylboron reactants bearing a hydrogen atom at the boron-bound stereogenic carbons undergo stereoinvertive coupling in the presence of a 6-phenyl-2,2′-bipyridine ligand with high enantiospecificity. α-Aminobenzylboronates bearing fully substituted boron-bound stereogenic centers also gave the 3,3-disubstituted isoindolinones with stereospecific stereochemical inversion in the presence of simple 2,2′-bipyridine as a ligand. 相似文献
39.
Wada M Yokota C Ogata Y Kuroda N Yamada H Nakashima K 《Analytical and bioanalytical chemistry》2008,391(3):1057-1062
A sensitive high-performance liquid chromatography (HPLC)–fluorescence method for determination of morphine (Mor) in rat brain
and blood microdialysates was developed using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) as a label. Mor was labeled with DIB-Cl under mild reaction conditions (at room temperature
for 10 min). The separation of DIB-Mor was carried out on an octadecylsilica (ODS) column with CH3CN/0.1 M acetate buffer (pH 5.4) within 14 min. The detection limits of Mor in brain and blood microdialysates at a signal-to-noise
ratio of 3 were 0.4 and 0.6 ng mL−1, respectively. The proposed method was successfully applied to the preliminarily study of potential pharmacokinetic interaction
between Mor and diclofenac. 相似文献
40.
Ohyama K Oyamada K Kishikawa N Ohba Y Wada M Maki T Nakashima K Kuroda N 《Journal of chromatography. A》2008,1208(1-2):242-245
Three new chiral stationary phases with different lengths of l-phenylalanine peptide were prepared by solid-phase synthesis with tert-butoxycarbonyl (Boc)-l-phenylalanine on silica. The effect of phenylalanine peptide length on enantioselectivity was studied. The best separation of R/S-warfarin was achieved by the chiral stationary phase with intermediate peptide length. These stationary phases were found to exist mainly in alpha-helical conformation by using FT-IR spectra. The end-capping reagents for the N-terminus of the peptide were also evaluated. 相似文献