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261.
Katsuya Nagayama Toshimasa Tanaka Kazuhiro Tanaka Hiroshi Hayami Shinichiro Aramaki 《Experiments in fluids》2008,44(5):843-850
Loach has a unique swimming style of bending the whole body and staying at the bottom of water. We studied the three-dimensional
flow field around and behind the loach using stereoscopic-PIV. We captured flow fields in horizontal and vertical plane, and
it seems loach leaves vortex tube arches. From the analysis of body motion and flow field, we propose flow structure with
vortex tube arches connected along the loach body. After being released, they are separated and flow away and dissipate.
This research article was submitted for the special issue on Animal locomotion: The hydrodynamics of swimming (Vol. 43, No.
5). 相似文献
262.
Akira Nagai Ryo Nishimura Yohei Hattori Eri Hatano Ayako Fujimoto Masakazu Morimoto Nobuhiro Yasuda Kenji Kamada Hikaru Sotome Hiroshi Miyasaka Satoshi Yokojima Shinichiro Nakamura Kingo Uchida 《Chemical science》2021,12(34):11585
Here, we present single crystalline capsules of a photoresponsive molecule produced by simple recrystallization from organic solutions without direct human processing. During the crystal growth process, a movie was taken of the capsule taking in the organic solution. The capsules responded rapidly (<1 s) to the UV light stimuli and released the captured solution or solute. In principle, they can take in any substance dissolved in organic solvents, and their size can be controlled. Moreover, the capsule can be broken by multi-photon excitation using a near-infrared laser within the biological window. Furthermore, because the molecular packing in the crystal is unidirectional, the response can be controlled by the polarization of the light. This study shows the new potential of photoresponsive molecules.A novel diarylethene formed “crystalline capsules” containing liquid inclusions, and chemicals trapped in the capsules were released by photoinduced breaking. Operations by multiphoton and linear polarized light were demonstrated. 相似文献
263.
[reaction: see text] A stereocontrolled synthesis of (-)-CP55,940, a potent cannabinoid receptor agonist, has been attained using a novel aldolization/retro-aldolization interconversion strategy, in which a temporarily generated chiral aldol motif plays essential roles. 相似文献
264.
Wolfgang Voegeli Koichi Akimoto Shinichiro Nakatani Toshio Takahashi Yoshihito Mitsuoka Hiroshi Sugiyama Hiroshi Kawata 《Surface science》2007,601(4):1048-1053
We have determined the structure of the 4H-SiC(0 0 0 1)-3 × 3 surface after exposure to small amounts of molecular oxygen at room temperature using surface X-ray diffraction. The 3 × 3 reconstruction remains until at least an exposure of 10,000 L, but the diffracted intensities change, indicating structural changes. Comparison of the Patterson maps of the clean and oxidized surface shows that the main changes occur at the Si tetramer on top of the 3 × 3 surface. Atomic positions for several models were fitted to the experimental data. A model in which oxygen atoms are inserted into the Si tetramer gives the best fit to the experimental data. The best-fit atomic positions agree well with those obtained using density functional calculations. 相似文献
265.
Reflection spectra of silicate, borate, phosphate, fluorophosphate and fluoride glasses are studied in the spectral region of 2–13 eV in order to understand their dispersion behaviors in the visible region from the point of view of atomic structures.The absorption bands due to bridging oxygen ions or fluorine ions are found at 11.6 eV and 10.4–9.5 eV in silicate glasses, at 10.2 and 8.8 eV in borate glasses, at 9.5 eV in phosphate glasses, at 11.2 eV in fluorophosphate glasses and at 11 eV in fluorozirconate glasses.In silicate glasses, the bands due to nonbridging oxygen ions are found in the region 8.8-4.9 eV. They shift to lower energies with increasing ionic radius, in the order of Ca2+, Sr2+ and Ba2+, for the glasses containing low valency cations, while they shift to higher energies with increasing ionic radius, in the order of Ti4+, Zr4+ and Th4+ or in the order of Nb5+ and Ta5+, for the glasses containing high valency cations.In glasses containing large amounts of PbO, strong bands due to PB2+ ions appear in the lower energy regions of 6.3–5.6 eV and 5.2–4.7 eV. 相似文献
266.
Taiki Morita Somaraju Yugandar Shinichiro Fuse Hiroyuki Nakamura 《Tetrahedron letters》2018,59(13):1159-1171
Isoxazole is an important pharmacophore that is critical for biological activity. The isoxazole ring ranks 33rd in frequency among the 351 ring systems found in marketed drugs, thus suggesting a great deal of interest in the synthesis of functional isoxazoles. In recent years, various approaches have been developed for the synthesis and functionalization of isoxazoles. This comprehensive survey summarizes the recent new synthetic approaches to functionalized isoxazoles, with particular focus on the last three years with regard to the following reaction types: (1) 1,3-dipolar cycloaddition, (2) condensation, (3) cycloisomerization, and (4) direct functionalization. 相似文献
267.
Kobayashi T Shiga M Murakami A Nakamura S 《Journal of the American Chemical Society》2007,129(20):6405-6424
Phenol blue (PB) is a primary skeletal structure part of indoaniline dyes and well-known as a solvatochromic dye. It has been recently observed by pump-probe (PP) transient absorption measurements that PB shows ultrafast ground state recovery within a few hundred femtoseconds after photoexcitation. In this work, the ultrafast photochemical reaction mechanism of PB has been investigated using direct ab initio (CASSCF) nonadiabatic molecular dynamics with the trajectory surface hopping (TSH) method. The swarm of trajectories starting from the S1 Franck-Condon (FC) point has mostly shown surface hops (nonadiabatic transitions) from the S1 state to the S0 state at 110-120 fs in the vicinity of an S1/S0 conical intersection and after decay to the S0 state bifurcated into two (Reverse and Forward) directions with almost the same branching ratio and reached the vicinity of the S0 minimum energy point at 200-300 fs, which is in good agreement with the fast time component of the ground state recovery in the PP measurements. After reaching the vicinity of the S0 minimum energy point, the trajectories showed a coherent vibration of bending motion between quinoneimine and aniline rings with a low frequency of 43 cm-1, which presumably corresponds to a coherently photoexcitation-induced vibrational mode with a low frequency recently observed by the PP measurements. 相似文献
268.
Tsukasa Iwabuchi 《Mathematical Methods in the Applied Sciences》2014,37(9):1273-1277
The Cauchy problem for the Keller–Segel system of parabolic elliptic type is considered for initial data in the Besov spaces with p < ∞ , and a sufficient condition is given on the existence and the uniqueness of local solutions. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
269.
Bhardwaj V Trabelsi K Singh JB Choi SK Olsen SL Adachi I Adamczyk K Asner DM Aulchenko V Aushev T Aziz T Bakich AM Barberio E Belous K Bhuyan B Bischofberger M Bondar A Bračko M Brodzicka J Browder TE Chen A Chen P Cheon BG Cho K Choi Y Dalseno J Doležal Z Eidelman S Epifanov D Gaur V Gabyshev N Golob B Haba J Hayasaka K Hayashii H Horii Y Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Inami K Ishikawa A Iwabuchi M Iwasaki Y Iwashita T Joshi NJ Julius T Kang JH Kawasaki T Kiesling C Kim HO Kim JB 《Physical review letters》2011,107(9):091803
We report a study of B→(J/ψγ)K and B→(ψ'γ)K decay modes using 772×10? B ?B events collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. We observe X(3872)→J/ψγ and report the first evidence for χ(c2)→J/ψγ in B→(X_{c ?cγ)K decays, while in a search for X(3872)→ψ'γ no significant signal is found. We measure the branching fractions, B(B(±)→X(3872)K(±))B(X(3872)→J/ψγ)=(1.78(-0.44)(+0.48)±0.12)×10(-6), B(B(±)→χ(c2)K(±))=(1.11(-0.34)(+0.36)±0.09)×10(-5), B(B(±)→X(3872)K(±))B(X(3872)→ψ'γ)<3.45×10? (upper limit at 90% C.L.), and also provide upper limits for other searches. 相似文献
270.
Shinichiro Iwai 《Journal of luminescence》2011,131(3):409-414
Photo-induced insulator to metal transitions (PIMT) in quarter filled layered organic conductors ET [bis(ethylenedithio)tetrathiafulvalene]-based salts α-(ET)2I3, θ-(ET)2RbZn(SCN)4, and κ-(d-ET)2Cu[N(CN)2Br] were investigated using ultrafast spectroscopy in the near, mid-infrared and terahertz (THz) regions. In charge ordered salts α-(ET)2I3 and θ-(ET)2RbZn(SCN)4, an immediate (<30 fs) generation of a microscopic metallic state is driven by the electronic process. Subsequently, condensation of the microscopic metallic domain to the macroscopic scale is accompanied by a small molecular rearrangement in α-(ET)2I3. However, in θ-(ET)2RbZn(SCN)4, a large structural difference between the insulator and metallic phases prevents stabilization of the macroscopic metallic state. In a dimer Mott insulator κ-(d-ET)2Cu[N(CN)2Br], photo-generation of the metallic state shows a finite rise time of ca. 1 ps, which is attributable to the photo-induced change of on-site Coulomb energy on each dimer (Udim) through dimeric molecular rearrangement. Thus, the ultrafast dynamics of PIMT depend strongly on the molecular arrangement in the layer of ET salts. 相似文献