Mechanism of hybrid-magnetic-circuit multi-couple motor

Discusses the interval between laminations in a permanent magnet inductor motor which makes the air gap magnetic field produced by the permanent magnet very uneven in the axial direction, and limits the performance of a motor. Proposes a hybrid magnetic circuit multi couple motor to compensate for the uneven air gap magnetic field, thereby improving the performance of a motor.

Multi-segment and Multi-ply Overlapping Process of Multi Coupled Activities Based on Valid Information Evolution

Complex product development will inevitably face the design planning of the multi-coupled activities, and overlapping these activities could potentially reduce product development time, but there is a risk of the additional cost. Although the downstream task information dependence to the upstream task is already considered in the current researches, but the design process overall iteration caused by the information interdependence between activities is hardly discussed; especially the impact on the design process＇ overall iteration from the valid information accumulation process. Secondly, most studies only focus on the single overlapping process of two activities, rarely take multi-segment and multi-ply overlapping process of multi coupled activities into account; especially the inherent link between product development time and cost which originates from the overlapping process of multi coupled activities. For the purpose of solving the above problems, as to the insufficiency of the accumulated valid information in overlapping process, the function of the valid information evolution （VIE） degree is constructed. Stochastic process theory is used to describe the design information exchange and the valid information accumulation in the overlapping segment, and then the planning models of the single overlapping segment are built. On these bases, by analyzing overlapping processes and overlapping features of multi-coupling activities, multi-segment and multi-ply overlapping planning models are built; by sorting overlapping processes and analyzing the construction of these planning models, two conclusions are obtained： （1） As to multi-segment and multi-ply overlapping of multi coupled activities, the total decrement of the task set development time is the sum of the time decrement caused by basic overlapping segments, and minus the sum of the time increment caused by multiple overlapping segments; （2） the total increment of development cost is the sum of the cost increment caused by all overlapping process. And then, based on overlapping degree analysis of these planning models, by the V1E degree function, the four lemmas theory proofs are represented, and two propositions are finally proved： （1） The multi-ply overlapping of the multi coupled activities will weaken the basic overlapping effect on the development cycle time reduction （2） Overlapping the multi coupled activities will decrease product development cycle, but increase product development cost. And there is trade-off between development time and cost. And so, two methods are given to slacken and eliminate multi-ply overlapping effects. At last, an example about a vehicle upper subsystem design illustrates the application of the proposed models; compared with a sequential execution pattern, the decreasing of development cycle （22%） and the increasing of development cost （3%） show the validity of the method in the example The proposed research not only lays a theoretical foundation for correctly planning complex product development process, but also provides specific and effective operation methods for overlapping multi coupled activities.

COMSOL Multiphysics在锂离子电池中的应用

作为一种具有前景的能量存储系统,锂离子电池需要进一步提高能量密度、功率密度、可靠性和循环稳定性,以满足不断增长的大型能源存储、电动汽车和便携式电子设备需求。当前对锂离子电池的实验研究仍然面临多个挑战,这些挑战包括电解液的导电性和安全性、高能量负极的沉积-剥离机制的优化、高能量正极的循环电压和容量维持、高电流条件下的界面极化和容量释放,以及在极端电流-温度-针刺条件下的热失控管理等问题。这些问题涉及到电-化-力-热等多个场的耦合作用,需要进行协同优化处理。COMSOL Multiphysics提供了一种可行的工具,通过求解多物理场耦合的连续方程,能够同时考虑载流子浓度、电流密度、电-化学势、温度、应力/应变和几何形态等综合信息的演化。本文概述了该工具在锂离子电池的电解液、负极和正极设计等方面的研究,并聚焦于多场耦合对电池性能的综合影响、多场耦合模拟方法以及理论模拟与实验表征的结合。最后,本文对理论与实验联合研究中的多场和多尺度问题进行了展望。

Characteristics of dual-frequency capacitively coupled SF_6/O_2 plasma and plasma texturing of multi-crystalline silicon

Due to it being environmentally friendly, much attention has been paid to the dry plasma texturing technique serving as an alternative candidate for multicrystalline silicon （mc-Si） surface texturing. In this paper, capacitively coupled plasma （CCP） driven by a dual frequency （DF） of 40.68 MHz and 13.56 MHz is first used for plasma texturing of mc-Si with SF6/O2 gas mixture. Using a hairpin resonant probe and optical emission techniques, DF-CCP characteristics and their influence on mc-silicon surface plasma texturing are investigated at different flow rate ratios, pressures, and radio-frequency （RF） input powers. Experimental results show that suitable plasma texturing of mc-silicon occurs only in a narrow range of plasma parameters, where electron density ne must be larger than 6.3 x 109 cm-3 and the spectral intensity ratio of the F atom to that of the O atom （[F]/[O]） in the plasma must be between 0.8 and 0.3. Out of this range, no cone-like structure is formed on the mc-silicon surface. In our experiments, the lowest reflectance of about 7.3% for mc-silicon surface texturing is obtained at an [F]/[O] of 0.5 and ne of 6.9 × 109 cm-3.

Multi-soliton solutions for the coupled modified nonlinear Schrdinger equations via Riemann–Hilbert approach

The coupled modified nonlinear Schrodinger equations are under investigation in this work. Starting from analyzing the spectral problem of the Lax pair, a Riemann-Hilbert problem for the coupled modified nonlinear Schrodinger equations is formulated. And then, through solving the obtained Riemann-Hilbert problem under the conditions of irregularity and reflectionless case, N-soliton solutions for the equations are presented. Furthermore, the localized structures and dynamic behaviors of the one-soliton solution are shown graphically.

A STUDY OF A FULLY COUPLED TWO-PARAMETER SYSTEM OF SEQUENTIAL FRACTIONAL INTEGRO-DIFFERENTIAL EQUATIONS WITH NONLOCAL INTEGRO-MULTIPOINT BOUNDARY CONDITIONS

In this article, we discuss the existence and uniqueness of solutions for a coupled two-parameter system of sequential fractional integro-differential equations supplemented with nonlocal integro-multipoint boundary conditions. The standard tools of the fixed-point theory are employed to obtain the main results. We emphasize that our results are not only new in the given configuration, but also correspond to several new special cases for specific values of the parameters involved in the problem at hand.

H_∞ couple-group consensus of stochastic multi-agent systems with fixed and Markovian switching communication topologies

The paper addresses the issue of H_∞ couple-group consensus for a class of discrete-time stochastic multi-agent systems via output-feedback control. Both fixed and Markovian switching communication topologies are considered. By employing linear transformations, the closed-loop systems are converted into reduced-order systems and the H_∞ couplegroup consensus issue under consideration is changed into a stochastic H_∞ control problem. New conditions for the mean-square asymptotic stability and H_∞ performance of the reduced-order systems are proposed. On the basis of these conditions, constructive approaches for the design of the output-feedback control protocols are developed for the fixed communication topology and the Markovian switching communication topologies, respectively. Finally, two numerical examples are given to illustrate the applicability of the present design approaches.

Novel Apriori-Based Multi-Label Learning Algorithm by Exploiting Coupled Label Relationship

It is a key challenge to exploit the label coupling relationship in multi-label classification（MLC）problems.Most previous work focused on label pairwise relations,in which generally only global statistical information is used to analyze the coupled label relationship.In this work,firstly Bayesian and hypothesis testing methods are applied to predict the label set size of testing samples within their k nearest neighbor samples,which combines global and local statistical information,and then apriori algorithm is used to mine the label coupling relationship among multiple labels rather than pairwise labels,which can exploit the label coupling relations more accurately and comprehensively.The experimental results on text,biology and audio datasets shown that,compared with the state-of-the-art algorithm,the proposed algorithm can obtain better performance on 5 common criteria.

Mathematical modeling for coupled solid elastic-deformation and gas leak flow in multi-coal-seams

Based on the new viewpoint of solid and gas interaction mechanics, gas leakage in a double deformable coal seam can be understood. That is, under the action of geophysical fields, the methane flow in a double deformable coal seam can be essentially considered to be compressible with time dependent and mixed permeation and diffusion through a pore cleat deformable heterogeneous and anisotropy medium. Based on this new viewpoint, a coupled mathematical model for coal seam deformation and gas leakage in a double coal seam was formulated and numerical simulations for gas emission from the coal seam are presented. It is found that coupled models might be closer to reality.

Method of Multi-Mode Sensor Data Fusion with an Adaptive Deep Coupling Convolutional Auto-Encoder

To address the difficulties in fusing multi-mode sensor data for complex industrial machinery, an adaptive deep coupling convolutional auto-encoder (ADCCAE) fusion method was proposed. First, the multi-mode features extracted synchronously by the CCAE were stacked and fed to the multi-channel convolution layers for fusion. Then, the fused data was passed to all connection layers for compression and fed to the Softmax module for classification. Finally, the coupling loss function coefficients and the network parameters were optimized through an adaptive approach using the gray wolf optimization (GWO) algorithm. Experimental comparisons showed that the proposed ADCCAE fusion model was superior to existing models for multi-mode data fusion.

Coupled Attribute Similarity Learning on Categorical Data for Multi-Label Classification

In this paper a novel coupled attribute similarity learning method is proposed with the basis on the multi-label categorical data（CASonMLCD）.The CASonMLCD method not only computes the correlations between different attributes and multi-label sets using information gain,which can be regarded as the important degree of each attribute in the attribute learning method,but also further analyzes the intra-coupled and inter-coupled interactions between an attribute value pair for different attributes and multiple labels.The paper compared the CASonMLCD method with the OF distance and Jaccard similarity,which is based on the MLKNN algorithm according to 5common evaluation criteria.The experiment results demonstrated that the CASonMLCD method can mine the similarity relationship more accurately and comprehensively,it can obtain better performance than compared methods.

Multi-coupled single scattering method of solving vector radiative transfer equations

A new method of multi-coupled single scattering （MCSS） for solving a vector radiative transfer equation is de- veloped and made public on Internet. Recent solutions from Chandrasekhar＇s X-Y method is used to validate the MCSS＇s result, which shows high precision. The MCSS method is theoretically simple and clear, so it can be easily and credibly extended to the simulation of aerosol/cloud atmosphere＇s radiative properties, which provides effective support for research into polarized remote sensing.

Multi-symplectic method for the coupled Schrdinger–KdV equations

In this paper, we present a multi-symplectic Hamiltonian formulation of the coupled Schrtidinger-KdV equations （CS＇KE） with periodic boundary conditions. Then we develop a novel multi-symplectic Fourier pseudospectral （MSFP） scheme for the CSKE. In numerical experiments, we compare the MSFP method with the Crank-Nicholson （CN） method. Our results show high accuracy, effectiveness, and good ability of conserving the invariants of the MSFP method.

Multi-symplectic scheme for the coupled Schrdinger-Boussinesq equations

In this paper, a multi-symplectic Hamiltonian formulation is presented for the coupled Schrdinger-Boussinesq equations （CSBE）. Then, a multi-symplectic scheme of the CSBE is derived. The discrete conservation laws of the Langmuir plasmon number and total perturbed number density are also proved. Numerical experiments show that the multi-symplectic scheme simulates the solitary waves for a long time, and preserves the conservation laws well.

Solving the atmospheric scattering optical transfer function using the multi-coupled single scattering method

The atmospheric scattering optical transfer function （OTF） is solved by applying the multi-coupled single scattering （MCSS） method to the three-dimensional radiative transfer equation （RTE） under the periodic ground condition. This approach is a direct hit to the atmospheric scattering OTF using the same original context of modulation transfer function （MTF） measurement, i.e., images of sinusoidal grating at different spatial frequencies. Both the amplitude and phase shift of the OTF at various zenith and azimuth angles can be obtained at an arbitrary spatial frequency.

Coupled Vibration Analysis of Vehicle-Bridge System Based on Multi-Boby Dynamics

For establishing the refined numerical simulation model for coupled vibration between vehicle and bridge, the refined three-dimensional vehicle model is setup by multi-body system dynamics method, and finite element method of dynamic model is adopted to model the bridge. Taking Yujiang River Bridge on Nanning-Guangzhou railway line in China as study background, the?refined numerical simulation model of whole vehicle and whole bridge system for coupled vibration analysis is set up. The dynamic analysis model of the cable-stayed bridge is established by finite element method, and the natural vibration properties of the bridge are analyzed. The German ICE Electric Multiple Unit (EMU) train refined three-dimensional space vehicle model is set up by multi-system dynamics software SIMPACK, and the multiple non-linear properties are considered. The space vibration responses are calculated by co-simulation based on multi-body system dynamics and finite element method when the ICE EMU train passes the long span cable-stayed bridge at different speeds. In order to test if the bridge has the sufficient lateral or vertical rigidity and the operation stability is fine. The calculation results show: The operation safety can be guaranteed, and comfort?index is “excellent”. The bridge has sufficient rigidity, and vibration is in good condition.

Multi-component Dirac equation hierarchy and its multi-component integrable couplings system

A general scheme for generating a multi-component integrable equation hierarchy is proposed. A simple 3M- dimensional loop algebra ~X is produced. By taking advantage of ~X a new isospectral problem is established and then by making use of the Tu scheme the multi-component Dirac equation hierarchy is obtained. Finally, an expanding loop algebra ~FM of the loop algebra ~X is presented. Based on the ~FM, the multi-component integrable coupling system of the multi-component Dirac equation hierarchy is investigated. The method in this paper can be applied to other nonlinear evolution equation hierarchies.

Approximate Solution of Oil Film Load-carrying Capacity of Turbulent Journal Bearing with Couple Stress Flow

The instability of the rotor dynamic system supported by oil journal bearing is encountered frequently, such as the half speed whirl of the rotor, which is caused by oil film lubricant with nonlinearity. Currently, more attention is paid to the physical characteristics of oil film due to an oil-lubricated journal bearing being the important supporting component of the bearing-rotor systems and its nonlinear nature. In order to analyze the lubrication characteristics of journal bearings efficiently and save computational c[~brts, an approximate solution of nonlinear oil film forces of a finite length turbulent journal bearing with couple stress flow is proposed based on Sommerfeld and Ocvirk numbers. Reynolds equation in lubrication of a finite length turbulent .journal bearing is solved based on multi-parametric principle. Load-carrying capacity of nonlinear oil film is obtained, and the results obtained by different methods are compared. The validation of the proposed method is verified, meanwhile, the relationships of load-carrying capacity versus eccentricity ratio and width-to-diameter ratio under turbulent and couple stress working conditions are analyzed. The numerical results show that both couple stress flow and eccentricity ratio have obvious influence on oil film pressure distribution, and the proposed method approximates the load-carrying capacity of turbulent journal bearings efficiently with various width-to-diameter ratios. This research proposes an approximate solution of oil film load-carrying capacity of turbulent journal bearings with different width-to-diameter ratios, whicb are suitable for high eccentricity ratios and heavy loads.

A generalized multi-field coupling approach and its application to stability and deformation control of a high slope

Human activities, such as blasting excavation, bolting, grouting and impounding of reservoirs, will lead to disturbances to rock masses and variations in their structural features and material properties. These engineering disturbances are important factors that would alter the natural evolutionary processes or change the multi-field interactions in the rock masses from their initial equilibrium states. The concept of generalized multi-field couplings was proposed by placing particular emphasis on the role of engineering disturbances in traditional multi-field couplings in rock masses. A mathematical model was then developed, in which the effects of engineering disturbances on the coupling-processes were described with changes in boundary conditions and evolutions in thermo-hydro-mechanical （THM） properties of the rocks. A parameter, d, which is similar to damage variables but has a broader physical meaning, was conceptually introduced to represent the degree of engineering disturbances and the couplings among the material properties. The effects of blasting excavation, bolting and grouting in rock engineering were illustrated with various field observations or theoretical results, on which the degree of disturbances and the variations in elastic moduli and permeabilities were particularly focused. The influences of excavation and groundwater drainage on the seepage flow and stability of the slopes were demonstrated with numerical simulations. The proposed approach was further employed to investigate the coupled hydro-mechanical responses of a high rock slope to excavation, bolting and impounding of the reservoir in the dam left abutment of Jinping I hydropower station. The impacts of engineering disturbances on the deformation and stability of the slope during construction and operation were demonstrated.

Analysis of high-frequency local coupling instability induced by multi- transmitting formula - P-SV wave simulation in a 2D waveguide

Local coupling instability will occur when the numerical scheme of absorbing boundary condition and that of the field wave equation allow energies to spontaneously enter into the computational domain. That is, the two schemes support common wave solutions with group velocity pointed into the computation domain. The key to eliminate local coupling instability is to avoid such wave solutions. For lumped-mass finite element simulation of P-SV wave motion in a 2D waveguide, an approach for stable implementation of high order multi-transmitting formula is provided. With a uniform rectangular mesh, it is proven and validated that high-freqaency local coupling instability can be eliminated by setting the ratio of the element size equal to or greater than x/2 times the ratio of the P wave velocity to the S wave velocity. These results can be valuable for dealing instability problems induced by other absorbing boundary conditions.