LiCoO2/LiMn2O4复合薄膜电极制备及其在高温下的电化学性能

LiCoO2/LiMn2O4复合薄膜电极制备及其在高温下的电化学性能;锂离子电池;表面包覆     

THE ROLE OF ISSUE LINKAGE IN MANAGING NONCOOPERATING BASINS: THE CASE OF THE MEKONG

The Mekong River (MR) is the major water source in Southeast Asia, sharedby six countries. There is a rush, by riparian states, to acquire sources of alternative energy and other benefits to meet growing demands for water and energy. China and Myanmar have refused to cooperate fully in the MR Forum, leading to increase risks within the region. Development of the water resources of the MR Basin is the subject of intense debate both within the Mekong region and internationally. This paper investigates the concept of issue linkage to resolve unidirectional externalities in the MR. Using linked games, the paper shows that the downstream nations can consider the use of linkage as a form of side payment in achieving a basin‐wide agreement. While this approach supports the Integrated Water Resource Management‐based Basin Development Strategy adopted by the Mekong River Commission in April 2011 for managing the region's sustainability development, facts on the ground suggest that traditional issues to be linked may not be sufficient. The paper addresses this observation and suggests a cadre of issues, including nontraditional ones, to be analyzed in a future work.     

VORTEX-SURFACE INTERACTION NOISE: A COMPENDIUM OF WORKED EXAMPLES

Students attending a graduate course on the Theory of Vortex Sound given recently at Boston University were required to investigate the low Mach number unsteady flow and the accompanying acoustic radiation for a selection of idealized flow-structure interactions. These included linear and non-linear parallel blade-vortex interactions for two-dimensional airfoils, and for finite span airfoils of variable chord; interactions between line vortices and surface projections from a plane wall; bluff-body interactions involving line and ring vortices impinging on circular cylindrical and spherical bodies, and vortex motion in the neighborhood of a wall aperture. In all cases, the effective source region was localized in either two or three dimensions, and could be regarded as acoustically compact, and the sound was calculated by routine numerical methods using the theory of compact Green functions. The results are collected together in this paper as a compendium of canonical solutions that provide qualitative and quantitative insight into the mechanisms responsible for sound production, and a database that can be used to validate predictions of more generally applicable numerical schemes.     

简单水热法合成石墨-CdSe复合材料及其光催化降解有机染料(英文)

A graphene-CdSe composite was synthesized by a facile hydrothermal method,and characterized by X-ray diffraction,scanning electron microscopy with energy dispersive X-ray analysis,transmission electron microscopy and UV-vis diffuse reflectance spectrophotometry.The graphene-CdSe composite efficiently catalyzed the photodegradation of methylene blue(MB),methyl orange(MO) and rhodamine B(Rh.B) in aqueous solution under UV or visible light irradiation.The graphene-CdSe composite exhibited a higher photocatalyt...     

Demi-linear analysis Ⅲ——demi-distributions with compact support

A series of detailed quantitative results is established for the family of demidistributions which is a large extension of the family of usual distributions.     

Ternary oil—water—amphiphile systems: self-assembly and phase equilibria

The micellization properties and phase behaviour of model ternary surfactant—oil—water systems were studied by grand canonical Monte Carlo simulations assisted by histogram reweighting techniques. Larson's lattice model was used for a symmetrical H₄T₄ surfactant, where H represents hydrophilic and T hydrophobic groups. In contrast to earlier studies, oil chains of variable length, from T to T₄, were studied and the effect of added oil on the critical micelle concentration (cmc) was determined quantitatively. It was found that the cmc decreases as the volume fraction of oil in the aqueous phase is increased. Longer oil chains have a stronger effect than shorter chains for the same volume fraction. The oil, tail and head density profiles were obtained for typical micelles. Simulation results for the density profiles indicate that long chain oils are almost exclusively located within the micellar aggregates, in agreement with single-chain mean-field theory predictions. Ternary phase diagrams were obtained both by simulations and by quasichemical theory. The results suggest that the critical micelle concentration line is directed towards the oil-lean corner of the three-phase triangle, if there is one present in the system. It was also found that the amount of oil that can be dissolved in the ternary system increases sharply at the surfactant critical micelle concentration, indicating that micellization greatly enhances oil solubility.     

Analytical expressions for the correlation function of a hard sphere dimer fluid

A closed form expression is given for the correlation function of a hard sphere dimer fluid. A set of integral equations is obtained from Wertheim's multidensity Ornstein-Zernike integral equation theory with Percus-Yevick approximation. Applying the Laplace transformation method to the integral equations and then solving the resulting equations algebraically, the Laplace transforms of the individual correlation functions are obtained. By the inverse Laplace transformation, the radial distribution function (RDF) is obtained in closed form out to 3D (D is the segment diameter). The analytical expression for the RDF of the hard dimer should be useful in developing the perturbation theory of dimer fluids.     

Adsorption isotherm of a Lennard-Jones nitrogen in a carbon slitlike pore

A density functional perturbation approximation based both on second-order perturbation theory and on the pore average density has been proposed to study the adsorption hysteresis of nitrogen in a carbon slit pore. The main advantage of the present approximation is that it is computationally much simpler than the original density functional approximation based on the second-order perturbation theory of liquids, and can be applied to several model fluids confined in a strong external field in order to study their structural and thermodynamic properties. The calculated adsorption hysteresis for the confined Lennard-Jones nitrogen is in very good agreement with computer simulation, even if its accuracy slightly deteriorates for the desorption branch. The calculated equilibrium particle density distributions also compare well with computer simulations, and are better than those of a density functional theory based on the so-called mean-field approximation.     

沙粒粒径在水平水流中对湍流调制及减阻效应的影响作用

运用基于欧拉-欧拉方法的混合欧拉多相流模型结合雷诺应力湍流模型,对较大雷诺数下的水平固液两相湍流进行了数值计算,主要考察了以Kolmogorov尺度(约为2v/ur)为临界值的细小沙粒颗粒在5％的固相体积分数下对湍流场的调制及其减阻效应.研究发现,无量纲颗粒直径dp+≤2的小颗粒减小了固液两相湍流的雷诺应力,并且三个方向上的速度脉动也被不同程度地削弱;而dp+=4的大颗粒使缓冲层区域的雷诺应力稍增大,在增强法向速度脉动的同时对流向脉动有抑制作用,并且值得关注的是,较大颗粒的存在导致缓冲层中的部分区域出现了流变现象.在减阻方面,较小的颗粒(dp+≤2)有大致相同的减阻表现,而大颗粒(dp+=4)已经失去了减阻性能,总体上看,在所研究的情形下微颗粒的减阻性能随着其粒径的增大而降低.