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951.
Fumiko Akagi Masaki MukohMasafumi Mochizuki Junko UshiyamaTakuya Matsumoto Harukazu Miyamoto 《Journal of magnetism and magnetic materials》2012,324(3):309-313
Thermally assisted magnetic recording (TAR) with bit-patterned media was investigated by micromagnetic simulation. The media were assumed to be FePt layers. The effective head-field margin as well as the increase in temperature margin and down-track shift margin was investigated. Conditions of the head and medium that lead to a recording density beyond 5 Tb/in2 were proposed. 相似文献
952.
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954.
In this article, the non-isothermal Poiseuille flow and its stability in a vertical annulus filled with porous medium are investigated. The flow is induced by external pressure gradient and buoyancy force due to linearly varying inner wall temperature. The non-Darcy model along with Boussinesq approximation has been used. The Chebyshev spectral-collocation method has been adopted to solve the governing equations related to basic flow as well as its stability. Special attention is given to understand the effect of curvature parameter of the annular geometry on the flow, heat transfer rate and stability of the stably stratified flow. A comprehensive numerical experiment indicates that reducing gap between two concentric cylinders decreases the heat transfer rate as well as the maximum magnitude of the flow velocity. It stabilizes the flow which has been shown through stability analysis. Furthermore, appropriateness of the Forchheimer term in the momentum equation has been examined by investigating the flow regime as well as its stability in the presence and absence of Forchheimer term. Finally, it has been found from the energy analysis at critical point that the thermal-buoyant instability is the only mode of instability for the considered range of different parameters. 相似文献
955.
《Comptes Rendus Chimie》2014,17(5):431-436
An efficient and convenient synthesis of 1,3-oxazine derivatives has been achieved by the one-pot, multicomponent condensation of α- or β-naphthol, an aniline and formaldehyde using thiamine hydrochloride (VB1) as a versatile biodegradable and reusable catalyst in water as a universal solvent. 相似文献
956.
Jane Huang 《Molecular physics》2015,113(15-16):2159-2168
The diffuse interstellar band (DIB) at 5797.1 Å is simulated based on three premises: (1) The carrier of the DIB is polar as concluded by T. Oka et al. from the anomalous spectrum toward Herschel 36 (Her 36). (2) The sharp central feature observed by P.J. Sarre's group is the Q-branch of a parallel band of a prolate top. (3) The radiative temperature of the environment is Tr = 2.73 K. A 2Π ← 2Π transition of a linear radical is simulated. Results depend on 10 parameters, with the rotational constant B being the most critical. Comparisons of calculated spectra with observed data constrain B, which in turn constrains the number of heavy atoms to 5 ≤ n ≤ 7. Upper limits based on the Her 36 spectrum and lower limits based on stability against photodissociation are also discussed. The latter is based on the assumption that the DIB molecules are produced top-down from the breakdown of dust rather than bottom-up by chemical reactions. A difficulty with this limit is that J.P. Maier's laboratory has observed many molecules within this size range, some of which have been tested astronomically. Candidates are discussed in light of many prolate tops observed by the P. Thaddeus and M.C. McCarthy microwave group. 相似文献
957.
An in situ‐generated catalytic system based on PdCl2 and primary amine‐based ligand exhibited excellent activity (up to 98% isolated yield) in the Suzuki–Miyaura cross‐coupling reactions of aryl bromides with arylboronic acids in water, at room temperature, without any additive. The efficiencies of the ligands follow the order: (C6H5)3CNH2 > C6H5CH2 NH2 > C6H5 NH2 > C6H11 NH2, which is in accordance with the palladacycle forming capacity of the respective ligands. Moderate‐to‐good yields (up to 78% isolated yield) of the coupling products were also obtained with less reactive aryl chlorides as substrates at room temperature in isopropanol using an alternative protocol based on Pd(OAc)2 and (C6H5)3CNH2. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
958.
Abdolali Ramazani Mohammad Almasi KashiGhafour Seyedi 《Journal of magnetism and magnetic materials》2012
Crystalline Co nanowires were pulse electrodeposited into nanoporous aluminum oxide template having an ultra-thinned barrier layer. The effects of off-time between pulses and electrolyte acidity on the microstructure and magnetic properties of the nanowires were investigated. Increasing the off time between pulses increased the crystallinity and the alignment of easy axis with the wire axis. The rate of these increments was seen to depend on the electrolyte acidity and reached its maximum at pH=5.25 electrolyte acidity. Optimizing the crystallinity and crystal orientation, a coercivity value of 3320 Oe and a squareness of>90% were obtained for pure Co nanowires. A 10% increase in coercivity was found after annealing the samples. 相似文献
959.
A novel one‐pot synthesis of biaryl derivatives has been developed starting from bromobenzaldehyde and phenylboronic acid in the presence of activated methylene compounds via sequential Suzuki coupling/Knoevenagel condensation in aqueous isopropanol medium at room temperature. Significantly, this strategy afforded a straightforward and efficient approach to construct original biaryls in which a new carbon double bond bound to activated moieties such as nitrile, ester and amide is formed from three simple substrates in a one‐pot procedure. Moreover, a wide scope of substrates could effectively participate in the process affording the target products in moderate to excellent yields. 相似文献
960.
The influence of Na2, CO3, K2CO3, and Li2CO3 addition on the relative volatility factor α of light and heavy water ai temperatures close to the isotope effect inversion temperature has been investigated. The measurements for Na2CO3 and K2CO3 solutions have been made in the temperature range. 100–330 °C at various salt concentrations. In the case of Li2CO3 temperature range and concentration was limited by the solubility of this salt. The factor α was determined by analysis of gas and liquid phases at equilibrium. Data on pure waters obtained by other investigators are listed for comparison. The temperature dependence of factor α for salt solutions and pure waters is presented in the form of equations derived from experimental data. 相似文献