71 research outputs found

    Extraction of Sm(III)and Nd(III) with N,N,N’,N’-tetrabutyl-3-oxy-diglycolamidefrom hydrochloric acid

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    The extraction behavior of Sm(III) and Nd(III) with N,N,N’,N’-tetrabutyl-3-oxa-diglycolamide (TBDGA) in 70% kerosene-30% n-octanol from hydrochloride acid wasstudied. The effect of hydrochloric acid concentration, extractant concentration,and temperature on the distribution of rare earth elementswas investigated. The extraction mechanism was established and the stoichiometry of the main extracted species was confirm to be SmCl3•2TBDGA and NdCl3•2TBDGA for Sm(III) and Nd(III), respectively. The extraction distribution ratio decreases with an increase in temperature, which demonstrates that the extraction reaction is exothermic. The IR spectra of the loaded organic phase and free extractant were recorded and discussed

    A Simulation Study on the Effect of Cavity Shapes on the Penetration of Linear Shaped Charges with Curved Liners

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    The finite element models of curved-liner shaped charges penetrating aluminum-alloy thin plates were constructed with the ANSYS/LS-DYNA software to analyze the effect of cavity shapes on the charge penetration with curved liners. The cavity height, radius, and spatial dimensions were numerically simulated. Simulation results indicate that these properties are important factors in determining the penetration of curved-liner charges. The penetration depth exhibits an initial increase followed by a decrease with the fixed cavity radius. When the cavity height is fixed, the penetration depth decreases with the cavity radius. When the cavity is semicircular, the penetration depth first increases and then decreases with the cavity radius and height.Построены конечноэлементные модели кумулятивных зарядов со сложнопрофильной облицовкой, проникающих через тонкие пластины из алюминиевого сплава. Использовано программное обеспечение ANSYS/LS-DYNA для анализа влияния формы выемки на их проницаемость. Выполнены численные расчеты высоты, радиуса и пространственных размеров выемки. Показано, что эти характеристики являются важными факторами при определении проницаемости зарядов. Глубина проникновения увеличивается, а затем уменьшается с увеличением высоты выемки при постоянном радиусе. При фиксированной высоте глубина проникновения уменьшается с увеличением радиуса. При полуокружной выемке глубина проникновения увеличивается, затем уменьшается с увеличением ее радиуса и высоты

    A Statistical Study on Photospheric Magnetic Nonpotentiality of Active Regions and Its Relationship with Flares during Solar Cycles 22-23

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    A statistical study is carried out on the photospheric magnetic nonpotentiality in solar active regions and its relationship with associated flares. We select 2173 photospheric vector magnetograms from 1106 active regions observed by the Solar Magnetic Field Telescope at Huairou Solar Observing Station, National Astronomical Observatories of China, in the period of 1988-2008, which covers most of the 22nd and 23rd solar cycles. We have computed the mean planar magnetic shear angle (\bar{\Delta\phi}), mean shear angle of the vector magnetic field (\bar{\Delta\psi}), mean absolute vertical current density (\bar{|J_{z}|}), mean absolute current helicity density (\bar{|h_{c}|}), absolute twist parameter (|\alpha_{av}|), mean free magnetic energy density (\bar{\rho_{free}}), effective distance of the longitudinal magnetic field (d_{E}), and modified effective distance (d_{Em}) of each photospheric vector magnetogram. Parameters \bar{|h_{c}|}, \bar{\rho_{free}}, and d_{Em} show higher correlation with the evolution of the solar cycle. The Pearson linear correlation coefficients between these three parameters and the yearly mean sunspot number are all larger than 0.59. Parameters \bar{\Delta\phi}, \bar{\Delta\psi}, \bar{|J_{z}|}, |\alpha_{av}|, and d_{E} show only weak correlations with the solar cycle, though the nonpotentiality and the complexity of active regions are greater in the activity maximum periods than in the minimum periods. All of the eight parameters show positive correlations with the flare productivity of active regions, and the combination of different nonpotentiality parameters may be effective in predicting the flaring probability of active regions.Comment: 20 pages, 5 figures, 4 tables, accepted for publication in Solar Physic

    Consumer xenocentrism in China: an exploratory study

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    Purpose Marketing research has focussed more on in-group favoritism and out-group derogation (i.e. ethnocentrism) than out-group favoritism and in-group derogation (i.e. xenocentrism). The purpose of this paper is to explore the xenocentric behavior in the consumer sphere to explain why some consumers have a bias for foreign products even when domestic ones are qualitatively similar or better. As the Chinese economy has experienced more than three decades of near double-digit growth and increased openness to foreign products, it is important to examine phenomena related to the formation of Chinese attitudes toward foreign products with the rising tensions between the seemingly irreversible globalization and Chinese re-awakening nationalism. Design/methodology/approach This study is based on a review of the extant literature and focus groups in three cities in China. Findings This study has found that consumer xenocentrism (CX) is prevalent in China, especially among the new emerging wealthy classes, younger consumers, and the local elite. It appears that Chinese consumers are psychologically or sociologically orientated or predisposed toward foreign (Western) goods. The findings from this study suggest that both consumer ethnocentrism and CX are possible or even expected. The short review of Chinese history presented here has shown that these phenomena can be explained by traditional in-group/out-group theories. Specifically, when there are too many xenocentrics, national esteem is threatened and this prompts many individuals to become more ethnocentric. Research limitations/implications This study is based on the literature and focus groups data, hence, the findings are not intended to be generalizable. Practical implications The findings from this study should be of interest to business practitioners and policy makers. Social implications The historical and cultural perspectives taken in this study indicate that understanding consumers’ xenocentric behavior entails knowledge and deep understanding of how cultural values and contemporary social-political forces interplay within consumers’ formation and change of attitudes toward the choice of domestic and foreign products. Originality/value This study shows that the ability of foreign products to meet the individual’s need or enhance his/her self-esteem more so than domestic products is indicative of something more than simply an international, cosmopolitan, or modern orientation. The fact that consumer foreign bias is found with both mundane and widely available products, expensive and inexpensive products, and conspicuous and non-conspicuous goods challenges the assumption that this phenomenon is simply traditional prestige-consumption behavior. Future research needs to be directed at measuring the CX construct and examine potential antecedents of such a behavior

    Subgrid modeling of anisotropic rotating homogeneous turbulence.

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    pp. 1-7International audienceWe investigate subgrid modeling of anisotropic rotating turbulence with a dynamic equation of structure functions of the filtered velocity field. The local volume-averaged structure function equation of rotating turbulence is introduced and an eddy viscosity subgrid model is obtained. The resulting subgrid model is similar to that of the study of Cui et al. [Phys. Fluids 16, 2835 (2004)]. It is directly related to the transfer term: the third-order structure function. This term can be computed dynamically during large eddy simulations (LES). Tests are successfully carried out in LES of decaying, rotating, homogeneous turbulence at high Reynolds numbers. Results are in excellent agreement when compared with those of Cambon et al. [J. Fluid Mech. 337, 303 (1997)]
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