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31.
32.
Large eddy simulation is used to investigate passive and reactive scalar mixing at high Reynolds Re and Schmidt Sc numbers in order to prove capability of the LES‐SGS micromixing approaches based on the eddy dissipation and DQMOM‐IEM models properly simulating liquid reacting flows. Simulations were performed for a fast neutralization reaction in a confined jet reactor. The mean profiles for passive scalar agree well with measurements. It was shown that the most contribution to the scalar variance is made by large scale motions whereas the contribution of fine scales smaller than typical inertial range scales is negligible. Thus, the existing LES models are capable of predicting the scalar variance at large Sc numbers. The results obtained for reactive transport revealed discrepancies in the determination of micromixing rate and product concentration. A special study was performed to investigate the dynamics of fine structures using locally refined box embedded into global grid. Typical statistical properties of fine structures were reproduced numerically. 相似文献
33.
Capillary driven surface oscillations of liquid argon (Tsat = 87.3 K at 1,013 hPa) have been investigated in a partly filled right circular cylinder under non-isothermal boundary conditions. The oscillations take place during the reorientation from the normal gravity surface position towards a new position upon step reduction of gravity. The situation is similar to the end of thrust in a rocket tank when the cold propellant moves along the warmer tank wall driven by capillary forces. The aim was to investigate the influence of the temperature difference between the slightly subcooled cryogenic liquid and the superheated cylinder wall on the oscillations and their characteristics in a single-component, two-phase system. Axial wall temperature gradients of averaged 0.15 K/mm ? 1.93 K/mm above the normal gravity surface position were implemented. A general dependence of the reorientation behavior on the gradient value was observed, concerning the apparent contact line behavior, the frequency and damping of the oscillations of the free surface center point, and the apparent contact angle. The behavior of the ullage pressure was found to follow the behavior of the contact line. 相似文献
34.
Daniel E. Lynch Uwe Geissler Nicholas J. Calos Barry Wood Nikolai N. Kinaev 《Polymer Bulletin》1998,40(4-5):373-380
Summary
In an attempt to produce a processible poly(pyrrol-2-ylsquaraine) by forming a copolymer of poly(pyrrol-2-ylsquaraine) with
polymethylmethacrylate, two synthetic routes were utilised. The first included forming the polysquaraine and then polymerising
the attached methacrylate groups to form the desired product and the second proceeded via the preformed methacrylate polymer, containing N-alkylpyrrole side chains, which was then condensed with squaric acid. Difficulties arose in the first route when the polysquaraine
product was found to be insoluble, hence preventing any further polymerisation but partial solubility during the second procedure
did allow bissquaraines to be formed and, as a consequence, the resultant product exhibited fluorescent properties. Yet the
desired processible poly(pyrrol-2-ylsquaraine) was not achieved.
Received: 30 October 1997/Revised version: 22 January 1998/Accepted: 23 January 1998 相似文献
35.
S. V. Sudareva M. V. Kuznetsov E. I. Kuznetsova Yu. V. Blinova E. P. Romanov I. B. Bobylev 《The Physics of Metals and Metallography》2009,108(6):569-578
Structure and dynamics of two interacting 180° domain walls of different polarity, which form a 360° wall, have been investigated analytically and numerically in a uniaxial ferromagnet with a large quality factor placed in a magnetic field. A strong influence of damping and field on the frequency and nature of the dynamic transformation of the structure of interacting domain walls from the Bloch to the Néel type and vice versa has been revealed. 相似文献
36.
37.
James S. Bendall Marzia Paderi Francesca Ghigliotti Nello Li Pira Vitoguido Lambertini Vladimir Lesnyak Nikolai Gaponik Giuseppe Visimberga Alexander Eychmüller Clivia M. Sotomayor Torres Mark E. Welland Christina Gieck Leonardo Marchese 《Advanced functional materials》2010,20(19):3298-3302
A novel all‐inorganic electroluminescent device is demonstrated based on highly luminescent CdTe nanocrystals intercalated within a laminar hydrotalcite‐like structure. The laminar scaffold acts to both support and distribute the CdTe nanocrystals. The device is synthesized using simple wet chemical processes at room temperature in ambient conditions. It has high thermal stability, operating continuously up to 90 °C, and a maximum efficiency at J = 0.12 A cm?2. The device is targeted at the automotive industry. 相似文献
38.
Oleksii Parniakov Olivier Bals Viacheslav Mykhailyk Nikolai Lebovka Eugene Vorobiev 《Food and Bioprocess Technology》2016,9(2):243-251
The effects of pulsed electric fields (PEF) and osmotic impregnation in glycerol solution on the amount of unfreezable water in apple were determined by means of low-temperature differential scanning calorimetry (DSC). The obtained data were compared with behaviour of pure water–glycerol solutions (sample WG). PEF treatment was applied using a near-rectangular monopolar generator with pulse duration of 100 μs at electric field strength of 800 V/cm. The osmotic impregnation of PEF-treated apple discs was done using water–glycerol (sample AWG) and apple juice–glycerol (sample AJG) osmotic solutions at different concentration of water or juice in glycerol, W = 30–100 wt%. The data evidenced that for the PEF-treated samples the glycerol was able to penetrate successfully inside apple tissue. The state diagrams for WG, AWG and AJG samples were rather similar. It was observed that free water existed only for moisture content above some minimum value. The unfreezable water content was the largest in AJG, followed by WG and AWG. The juice concentration in glycerol W ≈ 80 wt% was found to be optimal for preservation of the texture of PEF-treated samples. 相似文献
39.
E. P. Pozhidaev D. A. Mudretsov V. M. Shoshin Yu. P. Bobylev A. A. Zhukov V. G. Veselago 《Technical Physics Letters》2013,39(6):517-519
Designs of an IR polarizerless gate based on the electrically controlled light-scattering effect in a liquid crystal are presented. The radiation transmission in the wavelength range of 2.5–25.0 μm has been experimentally measured. 相似文献
40.