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101.
Kashiwagi T Amemiya F Fuchigami T Atobe M 《Chemical communications (Cambridge, England)》2012,48(22):2806-2808
We have successfully demonstrated that a microflow reactor is extremely useful in controlling reactions involving an unstable o-benzoquinone. The key features of the method are an effective o-benzoquinone generation and its rapid use for the following reaction without decomposition in a microflow system. 相似文献
102.
Fumihiro Ito 《Tetrahedron letters》2009,50(46):6252-8013
A new ionization method that uses metal-complex-based ionization probes containing the 2,6-bis(oxazolinyl)pyridine (pybox) ligand is presented. This method was proven to effectively ionize large complex molecules, including biomolecules. The preparation of the charged probes and their application to the ionization of biomolecules using cold-spray ionization mass spectrometry are shown. 相似文献
103.
Hideaki Takahashi Fumihiro Miki Hajime Ohno Ryohei Kishi Suguru Ohta Shin-ichi Furukawa Masayoshi Nakano 《Journal of mathematical chemistry》2009,46(3):781-794
The reaction mechanism for the dehydration of 1,4-butanediol in hot water has been investigated by means of the hybrid quantum
mechanical/molecular mechanical approach combined with the theory of energy representation (QM/MM-ER). We have assumed that
the proton transfers along the hydrogen bonds of the water molecules catalyze the reaction, where the transition state (TS)
forms a singlet biradical electronic structure. It has been revealed by the simulation that the biradical electronic state
at the TS changes to zwitterionic structure in solution due to the hydration of the polar solvent. Such the electronic structure
change gives rise to the substantial stabilization of the TS in hot water. As a result, the water-catalytic path becomes more
favorable in aqueous solution than another possible path that proceeds without proton transfers as opposed to the reaction
mechanism in the gas phase. Furthermore, the activation free energy computed by the present method is in excellent agreement
with the experimental result. 相似文献
104.
Fumihiro Chiba Teruo Ushijima 《Journal of Computational and Applied Mathematics》2009,233(4):1155-1174
Our fundamental solution method gives an analytic representation of the approximate solution for the reduced wave problem in the exterior region of a disc. The asymptotic behavior of this representation yields an approximate formula for the scattering amplitude. An error estimate for this formula is given. We add two numerical tests: the numerical estimate of errors; and profiles of scattering cross sections and the far-field coefficient. Both tests include cases of high wave numbers. 相似文献
105.
Stress fibers are contractile actomyosin bundles commonly observed in the cytoskeleton of metazoan cells. The spatial profile of the polarity of actin filaments inside contractile actomyosin bundles is either monotonic (graded) or periodic (alternating). In the framework of linear irreversible thermodynamics, we write the constitutive equations for a polar, active, elastic one-dimensional medium. An analysis of the resulting equations for the dynamics of polarity shows that the transition from graded to alternating polarity patterns is a nonequilibrium Lifshitz point. Active contractility is a necessary condition for the emergence of sarcomeric, alternating polarity patterns. 相似文献
106.
Xiaobin Ding Jiaoxia Yang Linfan Zhu Fumihiro Koike Izumi Murakami Daiji Kato Hiroyuki A. Sakaue Nobuyuki Nakamura Chenzhong Dong 《Physics letters. A》2018,382(34):2321-2325
A detailed-level collisional-radiative model for the M1 transition spectrum of the Ca-like W54+ ion as observed in an electron beam ion trap (EBIT) was constructed based on atomic data calculated by the relativistic configuration interaction method and distorted wave theory. The present calculated transition energy, rate and intensity of W54+ M1 transitions are compared with previous theoretical and experimental values. The results are in reasonable agreement with the available experimental and theoretical data. The synthetic spectrum explained the EBIT spectrum in the 12–20 nm region, while a new possibly strong transition has been predicted to be observable with an appropriate electron beam energy. The present work provides accurate atomic data that may be used in plasma diagnostics applications. 相似文献
107.
Microgravity experiments of single droplet combustion in oscillatory flow at elevated pressure 总被引:1,自引:0,他引:1
Yasuhiro Ogami Satoru Sakurai Syoichi Hasegawa Mehdi Jangi Hisashi Nakamura Kentaro Yoshinaga Hideaki Kobayashi 《Proceedings of the Combustion Institute》2009,32(2):2171-2178
An experimental study for 1-butanol single droplet flames in constant and oscillatory flow fields was conducted under microgravity conditions at elevated pressure. In the constant flow experiments, flow velocities from 0 to 40 cm/s were tested. Using obtained data of d2, the burning rate constants were evaluated. The burning rate constant in the quiescent condition was also calculated successfully at high pressure by the extrapolation method based on the Frössling relation. In the oscillatory flow experiments, the flow velocities were varied from 0 to 40 cm/s at the frequencies of 2–40 Hz. Results showed that the burning rate constant during the droplet lifetime varied following the quasi-steady relation at 0.1 MPa; however, in the conditions with higher frequencies at 0.4 MPa, the average burning velocity became larger than that for the constant flow case with the velocity equivalent to the maximum velocity in the oscillatory flow. Under the condition where the burning rate constant increased, it was observed that the flame did not sufficiently move back upstream, leading to enhancement of the heat transfer from the flame to the droplet surface. Therefore, the instantaneous burning rate constant increased. To investigate the mechanism of such flame behavior, the ratio of two characteristic times, τf/τD (τf: flow oscillation characteristic time, τD: diffusion characteristic time), were compared. As the flow oscillatory frequency increased, τf/τD becomes smaller. τf/τD also became smaller at high pressure. If τf/τD is small due to the small mass diffusion rate, the droplet flame could not move back to the appropriate position for the minimum velocity in steady flow, leading to an increase of the burning rate constant, especially in the case of higher frequency at high pressure. 相似文献
108.
The quantity of photons generated during fluorescence microscopy is principally determined by the quantum yield of the fluorescence dyes and the optical power of the excitation beam. However, even though low quantum yields can produce poor images, it is challenging to tune this parameter, while increasing the power of the excitation beam often results in photodamage. Here, we propose the use of stimulated emission (SE) as a means of enhancing both the signal intensity and signal-to-noise ratio during confocal fluorescence microscopy. This work experimentally confirmed that both these factors can be enhanced by SE radiation, through generating a greater number of photons than are associated with the standard fluorescence signal. We also propose the concept of stimulated emission enhancing fluorescence (SEEF) microscopy, which employs both the SE and fluorescence signals, and demonstrate that the intensity of an SEEF signal is greater than those of the individual SE and fluorescence signals. 相似文献
109.
The Mott relation between the electrical and thermoelectric transport coefficients normally holds for phenomena involving scattering. However, the anomalous Hall effect (AHE) in ferromagnets may arise from intrinsic spin-orbit interaction. In this work, we have simultaneously measured AHE and the anomalous Nernst effect (ANE) in Ga1-xMnxAs ferromagnetic semiconductor films, and observed an exceptionally large ANE at zero magnetic field. We further show that AHE and ANE share a common origin and demonstrate the validity of the Mott relation for the anomalous transport phenomena. 相似文献
110.
T. Ohtani R. Fujimoto H. Yoshinaga M. Nakahira Y. Ueda 《Journal of solid state chemistry》1983,48(2):161-167
The Cr3±xSe4 shows an order-disorder transition from the monoclinic Cr3Se4 type to the CdI2-type structure. This transition originates in the intralayer disordering of metal vacancies in the alternate partially filled metal layers along thec axis. The transition is reversible and of first order. The transition temperature vs composition curve has a maximum (~900°C) at a stoichiometric composition of Cr3Se4. A statistical treatment of this phenomenon was attempted via the Bragg-Williams approximation. 相似文献