Advanced Composite Solid Electrolytes for Lithium Batteries: Filler Dimensional Design and Ion Path Optimization

Composite solid electrolytes are considered to be the crucial components of all-solid-state lithium batteries, which are viewed as the next-generation energy storage devices for high energy density and long working life. Numerous studies have shown that fillers in composite solid electrolytes can effectively improve the ion-transport behavior, the essence of which lies in the optimization of the ion-transport path in the electrolyte. The performance is closely related to the structure of the fillers and the interaction between fillers and other electrolyte components including polymer matrices and lithium salts. In this review, the dimensional design of fillers in advanced composite solid electrolytes involving 0D–2D nanofillers, and 3D continuous frameworks are focused on. The ion-transport mechanism and the interaction between fillers and other electrolyte components are highlighted. In addition, sandwich-structured composite solid electrolytes with fillers are also discussed. Strategies for the design of composite solid electrolytes with high room temperature ionic conductivity are summarized, aiming to assist target-oriented research for high-performance composite solid electrolytes.     

Noncentrosymmetry in micropolar elasticity

Consequences of noncentrosymmetry in a micropolar elastic solid are considered. A solid which is isotropic with respect to coordinate rotations but not with respect to inversions, has three new elastic constants in addition to the six considered in the fully isotropic micropolar solid. The acentric micropolar solid is predicted to undergo torsional deformation when subjected to tensile load.     

Stresses and displacements of a transversely isotropic elastic halfspace due to rectangular loadings

Analytical solutions in exact closed-forms are obtained for stresses and displacements in an solid due to rectangular loading. The stresses and displacements are induced in the solid due to the vertical and horizontal loadings uniformly distributed on a rectangular area. The rectangular area is horizontally embedded in or on the solid. The solid occupies a space of semi-infinite extent and has a linear elastic property with transverse isotropy. The classical integral transforms are used in the solution formulation. The solutions are systematically presented in matrix forms and in terms of elementary harmonic functions. The solutions are easily implemented for numerical calculations and applied to problems encountered in engineering. Comparisons of the present solution with existing similar solutions are presented for the stresses and displacements induced by the vertical load. In addition, the numerical results of the stresses and displacements in the solid induced by the horizontal and vertical loads are also presented. These results illustrate the effect of different elastic constants of transversely isotropic solids on the stress and displacement fields.     

CFD simulation of particle segregation in a rotating drum. Part I: Eulerian solid phase kinetic viscosity

Although the Eulerian approach coupling the kinetic theory of granular flow is usually used to study granular flows with relative lower solid fractions, it can be used to study relative denser granular flows if appropriate solid phase kinetic viscosity values were adopted. A granular bed surface fitting (BSF) method is proposed to determine the appropriate solid phase kinetic viscosities of the granular flows in a rotating drum. The specularity coefficient is also used to address the interaction between particles and the drum wall. The BSF solid phase kinetic viscosity increases with decreasing of particle sizes and drum rotational speeds. The BSF solid phase kinetic viscosity and the specularity coefficient follow a power-law relationship with 0.6–1.1 as the exponent of the specularity coefficient. The BSF solid phase kinetic viscosities for the particles of two different sizes are used to study particle segregation in a rotating drum. The core thickening segregation mechanism and the segregation band formations are well predicted.     

Carbazolyl and anthryl substituted diacetylenes: studies of crystal structures and energy transfer in the polymerization of mixed crystals

Diacetylenes substituted with carbazole and anthracene side groups can be co-crystallized to form substitutional solid solutions. By solid-state polymerization of these mixed crystals, macroscopic single crystals of the corresponding co-polymers are obtained. The crystal structures of the monomers are discussed with regard to structural aspects of the formation of solid solutions and the reactivity in the solid state. The influence of isostructural doping on the polymerization and the energy transfer involved in the reaction are discussed.     

基于复阻尼理论的流固耦合地震时程响应研究

在粘滞阻尼系统的地震动力学方程基础上,建立了基于应力相关复阻尼理论的流固耦合地震动力学方程。根据复阻尼系统求解理论,利用Newmark-β积分法,编制了Rayleigh阻尼和复阻尼模型的流固耦合三维有限元程序。以深水薄壁钢管墩柱为例,计算了两种阻尼模型的流固耦合地震时程响应和复阻尼模型的损耗因子;对比分析了无水和有水两种工况下的动力响应,并研究了此两种阻尼模型地震响应的差异。研究表明,在加速度峰值为2m/s2的El-Centro波作用下,应力相关复阻尼方法计算的结构震动响应数值远大于传统的Rayleigh阻尼模型,考虑流固耦合效应时,结构的震动响应是不考虑此效应时的1.5～2倍多;损耗因子随着位移的增大而增大,并且考虑流固耦合效应时的损耗因子明显大于不考虑此效应的损耗因子值。     

A local RBF collocation method for band structure computations of 2D solid/fluid and fluid/solid phononic crystals

In this paper, an efficient local radial basis function collocation method (LRBFCM) is presented for computing the band structures of the two‐dimensional (2D) solid/fluid and fluid/solid phononic crystals. Both systems of solid scatterers embedded in a fluid matrix (solid/fluid phononic crystals) and fluid scatterers embedded in a solid matrix (fluid/solid phononic crystals) are investigated. The solid–fluid interactions are taken into account by properly formulating and treating the continuity/equilibrium conditions on the solid–fluid interfaces, which require an accurate computation of the normal derivatives of the displacements and the pressure on the fluid–solid interfaces and the unit‐cell boundaries. The developed LRBFCM for the mixed wave propagation problems in 2D solid/fluid and fluid/solid phononic crystals is validated by the corresponding results obtained by the finite element method (FEM). To the best knowledge of the authors, the present LRBFCM has yet not been applied to the band structure computations of 2D solid/fluid and fluid/solid phononic crystals. For different lattice forms, scatterers' shapes, acoustic impedance ratios, and material combinations (solid scatterers in fluid matrix or fluid scatterers in solid matrix), numerical results are presented and discussed to reveal the efficiency and the accuracy of the developed LRBFCM for calculating the band structures of 2D solid/fluid and fluid/solid phononic crystals. A comparison of the present numerical results with that of the FEM shows that the present LRBFCM is much more efficient than the FEM for the band structure computations of the considered 2D solid/fluid and fluid/solid phononic crystals. Copyright © 2016 John Wiley & Sons, Ltd.     

Solid lubricants: a review

The fundamental mechanisms of solid lubrication are reviewed with examples from well-known solid lubricants like the transition metal dichalcogenides and diamond-like carbon families of coatings. Solid lubricants are applied either as surface coatings or as fillers in self-lubricating composites. Tribological (friction and wear) contacts with solid lubricant coatings typically result in transfer of a thin layer of material from the surface of the coating to the counterface, commonly known as a transfer film or tribofilm. The wear surfaces can exhibit different chemistry, microstructure, and crystallographic texture from those of the bulk coating due to surface chemical reactions with the surrounding environment. As a result, solid lubricant coatings that give extremely low friction and long wear life in one environment can fail to do so in a different environment. Most solid lubricants exhibit non-Amontonian friction behavior with friction coefficients decreasing with increasing contact stress. The main mechanism responsible for low friction is typically governed by interfacial sliding between the worn coating and the transfer film. Strategies are discussed for the design of novel coating architectures to adapt to varying environments.     

一种基于ObjectARX技术的扫掠体求解算法

扫掠体的研究在机械制造、碰撞检测以及机器人路径规划等方面具有重要的意义。利用计算几何和计算机图形学的有关理论,论述了三维实体空间扫掠体的求解过程及步骤,提出了扫掠体的生成策略。通过误差分析探讨了影响算法误差的因素。在AutoCAD平台上利用面向对象的应用程序开发环境ObjectARX并结合VisualC 实现了三维实体扫掠体的生成。最后给出了扫掠体的生成实例。     

Numerical Simulation of Nucleate Boiling Phenomenon Coupled with Thermal Response of the Solid

The present work describes the response of a heated solid surface during nucleation, growth and departure of a single bubble. Two dimensional, axisymmetric, finite difference schemes are used to solve the governing equations in the liquid, vapor and solid phases. The interface between liquid and vapor phases is tracked by a level set method. An iterative procedure is used at the interface between the solid and fluid phases in order to match temperatures and heat fluxes. Time and space invariant heat fluxes are supplied at the solid base and calculations are carried out for solids with different thermo-physical properties and thicknesses. Near the three-phase contact line, temperatures in the solid are observed to fluctuate significantly over short periods as the bubble base first expands outwards then contracts inwards before departure. The results show that waiting and growth periods can be related directly to wall superheat. The functional relationship between waiting time and wall superheat is found to agree well with the correlations based on experimental data reported in the literature.     

LDV MEASUREMENTS OF SOLID-LIQUID SLURRY FLOW USING REFRACTIVE INDEX MATCHING TECHNIQUE

A refractive index matched facility for studying solid-liquid slurry flow was developed. The refractive index matching of the solid and liquid facilitates the use of non-intrusive—laser velocimetry to measure solid and liquid velocities for slurries with solid concentrations as high as 50 percent by volume. Silica gel and sodium iodide solution in water were used us the refractive index matched solid and liquid respectively. Tests were conducted on solid liquid slurry with 5 percent solid concentration by volume in the Reynolds number range of 700 to 8000. The Reynolds number ranges for the four flow regimes, stationary bed, saltation, heterogeneous and homogeneous flow were identified. It was shown that signal processing technique utilizing histograms and signal amplitude discrimination can be used to discriminate between liquid and solid velocities. The details of the facility and the results of the tests conducted on the slurry are discussed in this paper.     

Wave Propagation in a Green–Naghdi Thermoelastic Solid with Diffusion

The Green and Naghdi theory of thermoelasticity is applied to study plane-wave propagation in an elastic solid with thermo-diffusion. The governing equations of an elastic solid with generalized thermo-diffusion are solved to show the existence of three coupled longitudinal waves and a shear vertical (SV) wave in a two-dimensional model of the solid with thermo-diffusion. The reflection of plane waves from a thermally insulated stress-free surface of an elastic solid with thermo-diffusion is also studied. A non-homogeneous system of four equations in reflection coefficients is obtained. The speeds of the plane waves are computed numerically and plotted against frequency for a particular range. The complex absolute values of the reflection coefficients of all reflected waves are computed numerically and plotted against the angle of incidence of the striking wave at the free surface. The effects of diffusion parameters are shown graphically for speeds and reflection coefficients of plane waves.     

Solid State Porous Metal Production: A Review of the Capabilities,Characteristics, and Challenges

Porous metals have been under development for nearly a century, but commercial adoption remains limited. This development has followed two primary routes: liquid state or solid state processing. Liquid state foaming introduces porosity to a liquid or semi‐solid metal, and solid state foaming introduces porosity to a metal, which is fully solid. Either method may create pores by internal gas pressure or introducing metal around a template directly control porosity. Process optimization and commercial output has been primarily related to liquid state methods, as solid state processing is often more complex, diverse, and with lower throughput. Solid state methods, however, are often more versatile and offer greater control of pore characteristics. Ongoing advancements in solid state foaming have allowed for a wide array of metals and alloys to be made porous and the three‐dimensional structure to be precisely tailored. In general, solid state processing remains limited to niche applications, often with modest dimensions (cm scale). “Traditional” solid state processes are being further refined and extended, and continuing developments to reduce cost, increase output, and control pore characteristics are likely to produce important advancements in coming years. The extensive variability of pore quantity and morphology makes solid state processes suitable, and often preferable, for an assortment of functional and structural applications, with electrodes and biomedical devices being among the most popular in current research. Various techniques for introducing porosity, the way these methods are applied, important considerations, typical outcomes, and current applications are reviewed.

     

CFD-DEM study of the effects of solid properties and aeration conditions on heat transfer in fluidized bed

The solid properties are of significant influence on the thermal performance of the fluidized bed. In order to provide valuable information for the application of this equipment, a numerical study is carried to clarify the effects of solid properties on the heat transfer characteristics in a lab-scale fluidized bed by means of the CFD-DEM method. Specially, two aeration conditions, i.e. the same superficial velocity and the same fluidization number, are considered. The results show that the violent convective mechanism at bed bottom plays a significant role in the heating of the bed material. The entrainment of rising bubbles and hence solid mixing are the key factors to get better temperature uniformity of the bed during the heating process. With the decrease of particle density and size, the internal circulation of solid phase is strengthened under the same superficial velocity, while slightly weakened under the same fluidization number. Obvious resemblance can be captured between solid mixing and temperature uniformity, and the enhanced solid mixing usually leads to homogeneous temperature distribution of the bed. It can be found that the heating rate decreases with increasing solid density regardless of aeration setup. In addition, it is positively related to particle diameter under the same fluidization number, while keep unchanged under the same superficial velocity. Furthermore, enhanced solid mixing and better temperature uniformity can be captured with increasing solid heat capacity, which confirms that gas temperature shows considerable effect on gas-solid flow.     

Anisotropic effective moduli of microcracked materials under antiplane loading

This study focuses on the prediction of the anisotropic effective elastic moduli of a solid containing microcracks with an arbitrary degree of alignment by using the generalized self-consistent method (GSCM). The effective elastic moduli pertaining to anti-plane shear deformation are discussed in detail. The undamaged solid can be isotropic as well as anisotropic. When the undamaged solid is isotropic, the GSCM can be realized exactly. When the undamaged solid is anisotropic it is difficult to provide an analytical solution for the crack opening displacement to be used in the GSCM, thus an approximation of the GSCM is pursued in this case. The explicit expressions of coupled nonlinear equations for the unknown effective moduli are obtained. The coupled nonlinear equations are easily solved through iteration.     

全固态锂离子电池中金属锂负极界面优化改性研究

以共聚物PEDOT-co-PEG作为锂金属阳极的表面改性层,采用磷酸铁锂复合阳极和“石榴石型”物质以及聚合氧乙烷聚合物组成的固体电解质制备了全固态锂离子电池。采用SEM分析了锂金属充电-放电反复操作后的形态学改变;采用电化学组抗谱试验研究了改性后的锂金属以及复合固体电解质接触面的稳定性并对全固态锂离子电池的充电-放电性能和界面稳定性进行了研究。结果表明,未改性的锂金属在固态电池充电-放电过程中会生成锂枝晶,从而导致全固态锂离子电池的高电流密度容量快速衰变;“石榴石型”物质以及聚合氧乙烷聚合物组成的固体电解质与改性后的金属锂具有良好的接触面,从而扼制锂枝晶的形成,提高全固态锂离子电池的机械性能;在PEDOT-co-PEG共聚物改性锂金属后,全固态锂离子电池的平稳性显著提高,且容量减弱放缓。     

利用工业固体废弃物制备烧胀陶粒的研究进展

工业固体废弃物是一种放错位置的资源。阐述了利用工业固体废弃物制备烧胀陶粒的可行性,综述了以煤矸石、粉煤灰、钢渣、尾矿等工业固体废弃物为原料制备烧胀陶粒的国内外研究进展,并分析了利用工业固体废弃物制备烧胀陶粒目前存在的主要问题和发展前景。     

2.5D coupled BEM–FEM used to model fluid and solid scattering wave

We describe a hybrid method to study fluid and solid interaction problems in the frequency domain. The numerical method is based on subdomain decomposition. The BEM is used to model unbounded solid mediums, whereas the confined subdomains, both fluid and solid, are represented by the FEM. The analysis is carried out by superposing two‐and‐a‐half dimension (2.5D) problems for different longitudinal wave numbers. A novel 2.5D FEM formulation for inviscid fluids is proposed, which include the energy lost at the fluid boundary enclosure. The fluid and solid subdomains are coupled, and appropriate boundary conditions are imposed at the interfaces. The proposed technique is verified from analytical solutions. A cylindrical cavity located in an unbounded solid medium excited by a dilatational point source is studied. Computed results are in good agreement with the analytical solution. Later, noise and vibration in a concrete tunnel due to an internal pressure load is analysed with the proposed methodology. Results show that tunnel and soil displacements increase with the load speed, as did the air pressure inside the tunnel, according with the travelling ranges defined by the wave propagation velocities in each medium. Copyright © 2014 John Wiley & Sons, Ltd.     

Relationship between the residual electric resistance of solid solutions and the rate of their melting in contact with metals

The rates of melting of tin-, lead-, and indium-based binary solid solutions in contact with low-melting metals (Bi, Sn, In, Pb) have been measured. A linear relationship is established between the rate of contact melting in these systems and the residual resistances of solid solutions. The obtained relations are used to predict the rates of melting for various solid solutions in contact with metals.     

Intermediate phases in the region of a morphotropic transition and the properties of ferroelectric piezoceramics

It is established that the region of a morphotropic phase transition in ternary solid solution systems based on lead zirconate titanate exhibits a complicated structure. The maxima of the physical characteristics of solid solutions in this morphotropic phase transition region are determined to a considerable extent by an intermediate phase. A series of solid solutions with good prospects for applications in high-temperature piezoceramics technology are found.