Layered Structure Model Research Articles

A Regular Biporous Model of the Cathode Active Layer Structure of a Lithium-Oxygen Battery. Calculation of Overall Characteristics of the Cathode Active Layer

The active layer of a lithium-oxygen battery (LOB) cathode must have a complex structure consisting of two types of pores (macropores and mesopores). For successful operation of the cathode active layer during the LOB discharge, attempts are being made to create two types of pore clusters: a macropore cluster that provides the transport of oxygen to a zone, where the final product, lithium peroxide, is formed, and a mesopore cluster that guarantees the delivery of lithium ions. The structure of the cathode active layer composed of two types of clusters is optimized in model calculations. However, it from the experimental data, even after the actual implementation of these theoretical recommendations, that the LOB dimensional characteristics during the discharge (in particular, current density I, mA/cm2, and cathodic capacitance C, C/cm2) remain low. In the present work, a new type of cathode active layer structure was suggested: a regular biporous model. In this model, the channels for the supply with oxygen and lithium ions are separated from each other. This fact allows one to simultaneously and independently improve the operation of each of the two channels. The calculations showed a clear advantage of the active layers with this new structure. In particular, the current density i and cathode capacitance С raised to tens of mA/cm2 and about of a thousand of C/cm2.

Study on Home Chairs Design Evaluation for Low-and Middle-income Groups Based on User Experience

Pay attention to the home living environment of low-and middle-income groups, study the user-centered design evaluation method to guide the design of home chairs suitable for low-and middle-income groups. Introducing Analytic Hierarchy Process（AHP）into home chairs’ design evaluation, it establishes a different layer and different elements structure model based on sensory experience, behavioral experience, emotional experience and economic experience from the point of user experience. Scoring each element, it calculates and determines the weight value of every element, and forms an evaluation method of home chairs for low-and middle-income Groups. Using the method to evaluate the design schemes of 3 home chairs, it obtains the optimal scheme. Then, surveying the market sales data to verify the accuracy of the result. The evaluation method consists of four major elements: sensory experience(B1), 27%; behavior experience(B2), 41%; emotional experience(B3), 10%; economic experience(B4), 22%. The method can effectively solve the complex comparison of multiple elements in design evaluation and provide a comprehensive method combining qualitative and quantitative methods for product design, and provides reference for products design and evaluation of the same type

Syntheses, characterization and properties of two new dodeca-niobates presenting unprecedented features.

Two new dodeca-niobate materials, K3[Nb2O2][H7SiNb12O40]·16H2O (1) and [Cu(en)2]9[(VNb12V1.69Nb0.31O42en0.31)2]·20.69H2O (2) (en = ethylenediamine), have been obtained under hydrothermal conditions and characterized by IR, UV-Vis, XRD, and single crystal X-ray diffraction analysis. Single crystal X-ray analysis reveals that compound 1 presents a reasonable bridging layer structure model and that K plays a great role in the three-dimensional structure. Compound 2 is the first capped Keggin POM with organic ligand chelating the capping atom. The photocatalytic hydrogen evolution and styrene epoxidation catalytic properties of the two compounds were also assessed. Additionally, compound 1 is also a good photocatalyst to degrade RhB.

Academia a new knowledge supplier to the industry! Uncovering barriers in the process

PurposeIn the era of Industry 4.0, knowledge component plays a vital role in manufacturing. For tacking the new complexities of the business, a concept of knowledge supply chain (KSC) is being proposed, which takes into account of knowledge component. Higher education institutes (HEIs) which are primary creator of knowledge are important foundations of such supply chain and act as the “knowledge supplier.” The purpose of this paper is to focus on why the HEIs are failed to become knowledge supplier in developing country like India.Design/methodology/approachThis research paper adopts a resource-based theory to explore the concept and identify barriers which obstructs the progress of HEIs to become prominent knowledge supplier to industry. To tackle the research problem, an integrated hybrid approach of interpretive structural modeling–analytic hierarchy process is used. Expert elicitation was engaged to find out the prominence of each barrier and the interrelations among them.FindingsBased on literature review, eight critical barriers were recognized. The findings put forward a four layer structural model. Based on this model, various remedial actions are also suggested to eliminate the barriers or lessen their negative effects on KSC.Practical implicationsThis study finds its practical implication in higher education reforms as the identified barriers could enhance the decision-making quality regarding academia–industry interaction.Social implicationsUsing the results of the study, HEIs could improve their social sustainability as they have different stakeholders covering wider sections of society and one being industry.Originality/valueMost of the existing studies talk about short-term interactions like technology transfer. This study takes into account the barriers which are acting as roadblocks in long-term knowledge supplying role of HEIs.

The layered structure model for winonaite parent asteroid implicated by textural and mineralogical diversity

The winonaites are primitive achondrites that are associated with IAB iron meteorites. They provide valuable insights into differentiation processes on asteroids in the early Solar System. However, there is still little understanding of the lithological diversity as well as the structure of the winonaite parent asteroid. In this work, we report the petrologic texture and mineralogy of a suite of winonaites (i.e., Northwest Africa (NWA) 725, NWA 6448, NWA 4024, Grove Mountains (GRV) 022890, GRV 021663, and Sahara (SAH) 02029) that exhibit a wide diversity of petrographic textures from primitive chondritic texture to coarse-grained equigranular texture. In particular, we recognized an unusual winonaite (SAH 02029) with a distinctive mineralogy and mineral chemistry (e.g., depleted in troilite, plagioclase contains melt inclusions, high plagioclase An values, and LREE-depleted clinopyroxene). The petrological and mineralogical features of SAH 02029 indicate that this meteorite has undergone silicate partial melting and may represent the residue of ~ 5–10 vol% partial melting. The textural and mineralogical diversity among winonaites suggests that the winonaite-IAB parent asteroid would have formed a four-layered structure during its evolution history: (1) surface layer consisting of precursor chondritic materials; (2) subsurface layer composed of diverse lithologies that experienced limited metamorphism and FeNi–FeS partial melting; (3) deep residues of silicate partial melting; and (4) interior layer consisting of incomplete differentiation metal pools. This conclusion enables us to establish constraints on the evolution history of winonaite-IAB parent body.

An Investigation of Damping Mechanism in Two-Layered Beam with General Sectional Shape

Objectives The paper aims to develop a theory model of clamped layered structures for parameter study of a mechanical damper. The model can be applied to many cantilever friction cases such as general shape cantilever beams, different material cantilever beams, different cross-section beams, non-uniform thickness beams, etc.

Measurement Method for Dispersion States of Filler Particles in Particulate Composite Materials by Macroscopic Permittivity

Abstract A new model for estimating macroscopic permittivity was proposed to predict filler particles' dispersion states in a particulate composite material. In the model, the estimation targets are randomly packed composite materials. The composite materials were represented as a cluster of unit cells. A proposed layer structure model connected the unit cells. The macroscopic permittivity was estimated by calculating the synthetic capacity of the cluster. The proposed model was validated by comparisons between estimated and measured macroscopic permittivity of several particulate composite materials. It was also identified that the proposed model could estimate the permittivity more accurately than an existing theoretical equation's one due to considering the effects for the dispersion states of filler particles. Furthermore, it was indicated that the proposed model could also estimate the dispersion states of filler particles by the measured permittivity. The applicability of the method was confirmed by comparisons between estimated and experimental dispersion states of filler particles.

Numerical and experimental nonlinear dynamic response reduction of smart composite curved structure using collocation and non-collocation configuration

In this work, a generic geometrical nonlinear mathematical model of smart composite curved shell panels has been developed for the evaluation of the linear and nonlinear dynamic responses. Further, the dynamic deflections are reduced by employing the piezoelectric material with the parent composite using two different arrangements (sensor and actuator). The current layered structure model is developed based on the higher-order mid-plane kinematics including the stretching effect. The electric potential due to the piezoelectric material included via a quadratic function of thickness for the current combined electro-elastic modeling. The geometrical distortion of the smart shell panel structure accounted via Green-Lagrange strain field including all of the nonlinear higher-order terms. The desired responses are evaluated computationally using an original computer code (MATLAB environment) with the help of the current higher-order model and finite element steps. The nonlinear dynamic deflection values are obtained through the direct iterative method in conjunction with Newmark’s integration. Additionally, the accuracy of the proposed model is demonstrated via comparison study with the available published literature with and without electric field potential. The reduction of response frequencies is also compared with the in-house experimental data. Lastly, few more numerical examples are computed for the various geometrical parameter including the shell configuration and the comprehensive behaviour of the currently developed nonlinear numerical model for the analysis of smart layered structure discussed in details.

A new low-carbon design method based on multi-agent interactive reinforcement learning

With the development of manufacturing industry, considerable attention has been paid to the issue of environmental problems caused by the manufacturing process. One of the most important methods to solve this kind of problem is the low-carbon design of the products before manufacturing process. Therefore, a new part structure low-carbon design method is proposed in this paper. At first, the layered structure model based on part features is constructed in order to divide the product into part features, and as a result, the carbon footprint is calculated for each part feature. Then, the part features are clustered into several classes looking forward to find the higher carbon emissions part features as initial features for low-carbon design. After that, the multi-agent interactive reinforcement learning method is performed on the topological path of multiple initial parts using the Q-learning algorithm in Markov environment, so as to meet the design requirements of low-carbon design. Finally, a 6400 kN injection molding machine moving template design was taken as an example to verify the effectiveness of the proposed low-carbon design method.

Scattering of torsional surface waves in a three layered model structure

In this article, a comparative study has been made to investigate the scattering behaviour of three layered structure model on torsional surface wave. For such model intermediate layer is taken as fiber reinforced composite, resting over a dry sandy Gibson substratum and underlying by different anelastic media. We consider two distinct mediums for topmost layer. In the first case, topmost layer has been taken as fluid saturated homogeneous porous layer, while in the second case the fluid saturated porous layer has been replaced by a transversely isotropic layer. Simple form expression for the secular equation of torsional surface wave has been worked out in both the cases by executing specific boundary conditions, which comprises Whittaker\'s function and its derivative, for imminent result that have been elaborated asymptotically. Some special cases have been constituted which are in excellent compliance with recorded literatures. For the sake of comparative study, numerical estimation and graphical illustration have been accomplished to identify the effects of the width ratio of the layers, Biot\'s gravity parameter, sandy parameter, porosity parameter and other heterogeneity parameters corresponding to the layers and half spaces, horizontal compressive and tensile initial stress on the phase velocity of torsional surface wave.

Differential Geometry Soft Variable Structure Control of Magnetic Levitation Movement Stage

Background: It is easy to carry out a wide range of high-precision micro movement on the magnetic levitation stage which also turns to be suitable in precision manufacturing and ultra-precision measurement field. In view of the strong coupling and nonlinear characteristics of the dynamic model of the sandwich layer structure, the differential geometry soft variable structure control method is proposed. Keywords: Magnetic levitation movement stage, differential geometry, feedback linearization, soft variable structure controller, variable saturation, upside coil.

A three-dimensional modelling of the layered structure of comet 67P/Churyumov-Gerasimenko

We provide a three-dimensional model of the inner layered structure of comet 67P based on the hypothesis of an extended layering independently wrapping each lobe. A large set of terrace orientations was collected on the latest shape model and then used as a proxy for the local orientation of the surfaces of discontinuity which defines the layers. We modelled the terraces as a family of concentric ellipsoidal shells with fixed axis ratios, producing a model that is completely defined by just eight free parameters. Each lobe of 67P has been modelled independently, and the two sets of parameters have been estimated by means of non-linear optimization of the measured terrace orientations. The proposed model is able to predict the orientation of terraces, the elongation of cliffs, the linear traces observed in the Wosret and Hathor regions and the peculiar alignment of boulder-like features which has been observed in the Hapi region, which appears to be related to the inner layering of the big lobe. Our analysis allowed us to identify a plane of junction between the two lobes, further confirming the independent nature of the lobes. Our layering models differ from the best-fitting topographic ellipsoids of the surface, demonstrating that the terraces are aligned to an internal structure of discontinuities, which is unevenly exposed on the surface, suggesting a complex history of localized material removal from the nucleus.

Abnormal Polarity Effects of Streamer Discharge in Propylene Carbonate under Microsecond Pulses**Supported by the National Natural Science Foundation of China under Grant No 51677190, and the Hunan Provincial Natural Science Foundation of China under Grant No 2017JJ1005.

Propylene carbonate (PC) has a great potential to be used as an energy storage medium in the compact pulsed power sources due to its high dielectric constant and large resistivity. We investigate both the positive and negative breakdown characteristics of PC. The streamer patterns are obtained by ultra-high-speed cameras. The experimental results show that the positive breakdown voltage of PC is about 135% higher than the negative one, which is abnormal compared with the common liquid. The shape of the positive streamer is filamentary and branchy, while the negative streamer is tree-like and less branched. According to these experimental results, a charge layer structure model at the interface between the metal electrode and liquid is presented. It is suggested that the abnormal polarity effect basically arises from the electric field strength difference in the interface between both electrodes and PC. What is more, the recombination radiation and photoionization also play an important role in the whole discharge process.

Oxidation rates of aluminium nitride thin films: effect of composition of the atmosphere

This paper presents an analysis of thermal oxidation kinetics for Aluminium nitride (AlN) epitaxy layers using three methods: dry, wet and mixed. The structures thus obtained were examined by means of scanning electron microscope, energy-dispersive X-ray spectroscopy, spectroscopic ellipsometry and secondary ions mass spectroscopy. On the basis of the investigation results, a model of layer structure after oxidation was proposed, the thickness of the layers was assessed and the refractive indices for particular layers were determined. The modelling results prove that AlN thermal oxidation in dry oxygen follows the logarithmic law, wet oxidation follows the parabolic law, whereas mixed oxidation follows the linear law.

Simulation Analysis of Strength of Double Layer Structure of Prefabricated Substation

The construction of the substation in the urban center has become a common phenomenon. There is a need to consider the cost of land, and make the substation covering a small area, safe and economical. This paper presents a new model of substation built with assembled upper and lower double layer structure of module blocks in the urban center, and proposes to install 110kV of prefabricated cabin on the top of 10kV and 35kV of prefabricated cabin, with a small area and easy construction, but the strength of double layer structure becomes the key to design. Based on the finite element theory, this paper establishes a finite element model of double layer structure of prefabricated substation in the finite element software ABAQUS, and carries out strength simulation analysis of the most unfavorable conditions, of which the inclined degree of the entire structure is 5°, and the seismic intensity is 8°. The research results show that: when the inclined degree of the entire structure is 5°, the maximum stress of the structure is 92.49MPa, and the safety factor of strength is 2.5; when the seismic intensity is 8°, the horizontal load excitation has a greater impact on the double layer structure, the maximum stress is 160.5MPa, and the safety factor is 1.5; the vertical load excitation has a less impact, and the maximum stress is only 30.3MPa. In the early period of design of the strength simulation analysis method, this paper can obtain the safety factor of strength of structure under the most unfavorable conditions, which has reference significance on the design and optimization of the structure of substation.

Glancing angle deposition of SiO2 thin films using a novel collimated magnetron sputtering technique

A novel deposition flux collimation technique has been explored in combination with glancing angle deposition geometry in radio frequency magnetron sputtering deposition technique with a motive to tailor the refractive index of silicon di-oxide thin film. In this technique, a collimating plate has been placed in parallel to the substrate at variable substrate to collimator distances (DSC=4mm, 6mm and 9mm) and the effect of DSC on various properties of the deposited film at different spatial locations on the substrate has been investigated. The use of such collimator was found to be highly effective in reducing the refractive index of the deposited film. A lowest refractive index of ~1.31 @ 550nm of SiO2 was achieved by using this novel collimation technique in combination with glancing angle deposition geometry which is not possible by glancing angle deposition geometry alone in the framework of non-directional deposition flux in magnetron sputtering technique. Variable angle spectroscopic ellipsometry (VASE) has been employed to accurately determine thickness and refractive index of the deposited films at various spatial locations of the sample. Ellipsometry data fitting model at different spatial locations has been verified by simulating the transmission spectrum based on the layer structure model obtained from ellipsometry modeling and then comparing it with that of the experimentally measured transmission spectra. For a given DSC an optimum location on the substrate surface was obtained to exhibit lowest refractive index. FTIR measurement showed no significant difference in bonding behavior of SiO among different representative spots of the deposited SiO2 samples. AFM measurement on various spatial locations indicates a possible strong correlation between variation of refractive index and the grain size which is again affected by the degree of collimation and ad atom kinetic energy at various spatial locations.

Design of Phosphor White Light Systems for High-Power Applications

We developed a strategy that transforms phosphor down-converting white light sources from low-power systems into efficient high-power ones. To incorporate multiple phosphors, we generalized and extended a phosphor layer model, which we term CCAMP (color correction analysis for multiple phosphors). CCAMP describes both the scattering and saturation of phosphor materials and allows modeling of different layered structures. We employed a phosphor mixture comprising YAG:Ce and K2TiF6:Mn4+ to illustrate the effectiveness of the model. YAG:Ce’s high density and small particle size produce a large amount of scattering, while the long (4.8 ms) photoluminescent lifetime of K2TiF6:Mn4+ results in saturation at high pump power. By incorporating experimental photophysical results from the phosphors, we modeled our system and chose the design suitable for high-power applications. We report the first solid-state phosphor system that creates warm white light emission at powers up to 5 kW/cm2. Furthermore, at this high p...

Study on the Impact Resistance of Bionic Layered Composite of TiC-TiB₂/Al from Al-Ti-B₄C System.

Mechanical property and impact resistance mechanism of bionic layered composite was investigated. Due to light weight and high strength property, white clam shell was chosen as bionic model for design of bionic layered composite. The intercoupling model between hard layer and soft layer was identical to the layered microstructure and hardness tendency of the white clam shell, which connected the bionic design and fabrication. TiC-TiB2 reinforced Al matrix composites fabricated from Al-Ti-B4C system with 40 wt. %, 50 wt. % and 30 wt. % Al contents were treated as an outer layer, middle layer and inner layer in hard layers. Pure Al matrix was regarded as a soft layer. Compared with traditional homogenous Al-Ti-B4C composite, bionic layered composite exhibited high mechanical properties including flexural strength, fracture toughness, compressive strength and impact toughness. The intercoupling effect of layered structure and combination model of hard and soft played a key role in high impact resistance of the bionic layered composite, proving the feasibility and practicability of the bionic model of a white clam shell.

Microwave absorption by hydrogen plasma in carbon nanotubes films with layered dielectric structure

A layered structure model is proposed for microwave dielectric properties of nonhomogeneous hydrogen plasma in carbon nanotubes (CNTs) film. Using the transfer matrix method for solving electromagnetic wave propagation equation, the microwave attenuation of the film is calculated in the range of 0–30 GHz under different conditions. It is found theoretically that with the increase of hydrogen plasma nonhomogeneity, the frequency bandwidth of strong microwave absorption by the film increases markedly. The application of a moderate static magnetic field can effectively improve microwave attenuation properties of hydrogen plasma in CNTs. The numerical results are in good agreement with the available experimental data.

Structure and Field Emission Properties of CNx Powders Synthesized by a Polymerization Process

The CNx powders were prepared by a polymerization process. The phase structure and bonding structure of the as-prepared powder were analyzed by X–ray diffraction and X–ray photoelectron spectroscopy, respectively. To prepare CNx field emission cathode, the CNx powders were coated onto Ti substrate using a suspension sedimentation method, followed by an annealing treatment to form a TiC phase. A three layer (Ti substrate–TiC joint network–CNx particles) structure model was proposed to explain the electron field emission properties for the as-prepared field emission cathode. The field emission measurement shows that for the as-prepared CNx cathode, the threshold electric field is 2.04 V/μm and the emission current density at 3.73 V/μm is 158 μA/cm.