A CLOSED SYSTEM OF EQUATIONS FOR DENSE TWO-PHASE FLOW AND EXPRESSIONS OF SHEARING STRESS OF DISPERSED PHA’E AT A WALL

Inthis paper, each of the two phases in dense two-phase flow is considered as continuous medium and the fundamental equations for two-phase flow arc described in Eulerian form. The generalized constitutive relation of the Bingham fluid is applied to the dispersed phase with the analysis oj physical mechanism of dense two-phase flow. The shearing stress of dispersed phase at a wall is used to give a boundary condition. Then a mathematical model for dense two-phase flow is obtained. In addition, the expressions of shearing stress of dispersed phase at a wall is derived according to the fundamental model of the friclional collision between dispersed-plutse particles and the wall.

The i-E Equations of Steady-state Voltammograms at Microdisk Electrodes

Based on the theories of conventional electrodes, as well as the properties of microdisk electrode, the i-E equations for chronoamperometry at disk microelectrode for reversible, quasi-reversible and irreversible systems are derived. Steady-state voltammograms for the oxidation of [Fe(CN)6]4- , Fe2+ and ascorbic acid were measured at a series of microdisk electrodes with different radii. The conventional log-plot shows that oxidations of [Fe(CN)6]4- and ascorbic acid are reversible and totally irreversible, respectively, but the oxidation of Fe2+ is reversible at larger radius microdisk electrodes and quasi-reversible at smaller radius microdisk electrodes. The application of the log-plot to the voltammograms yielded a straight line, its slope allows us to evaluate the charge transfer coefficient and the intercept gives values of the electron transfer rate constant.

Investigations on if-E Curve in Cyclic Derivative Chronopotentiometry(Ⅵ)——Theoretical Equations of if-E Curves in the Case of Quasi-reversible and Irreversible Electrode Reactions

The theory of if-E curve in cyclic derivative chronopotentiometry is presented. Theoretical equations of if-E curves in the case of quasi-reversible and irreversible electrode reactions are deduced respectively.

基于SEM和神经网络的移动社交电商用户隐私信息披露意愿研究

在移动社交电商情境中,用户的交互方式发生改变,个人隐私信息安全问题凸显,上述变化将会对用户的隐私信息披露意愿产生重要影响。为了探究移动社交电商用户隐私信息披露意愿的影响因素,本文基于S-O-R理论建立结构方程模型,旨在探究影响用户隐私信息披露意愿的影响因素及其作用机理。结果表明隐私政策有效性、隐私设置有效性、信息交互、情感交互等因素均正向显著影响用户隐私信息披露意愿。在此基础上,基于平台特征和用户感知收益构建了GA-BP神经网络预测模型,并针对不同预测结果提出具体应对措施。最终,文章从隐私信息安全保障和平台个性化服务等方面提出促进移动社交电商平台可持续发展的建议。

A connection between the(G'/G)-expansion method and the truncated Painlevé expansion method and its application to the mKdV equation

Recently the （G′/G）-expansion method was proposed to find the traveling wave solutions of nonlinear evolution equations. This paper shows that the （G′/G）-expansion method is a special form of the truncated Painlev＇e expansion method by introducing an intermediate expansion method. Then the generalized （G′/G）-（G/G′） expansion method is naturally derived from the standpoint of the nonstandard truncated Painlev＇e expansion. The application of the generalized method to the mKdV equation shows that it extends the range of exact solutions obtained by using the （ G′/ G）-expansion method.

The Two Patterns of High Exact Difference in Convection Equation

This paper gives two patterns of high exact d ifference in solving convection equation. The error of cut section is to O(Δ t 2+Δx 4).

基于APEC-SEM的在线学习平台用户体验设计研究

目的为改善学生用户对在线学习平台的体验满意度,使设计师精准把握设计重点与优先级,以有效提升平台用户体验、促进平台的可持续发展。方法在APEC用户体验模型的基础上引入结构方程,提出一种在线学习平台用户体验设计框架。通过理论模型结合深度访谈,提取影响在线学习体验的设计要素,并通过问卷分析建立在线学习平台用户体验满意度的结构方程模型,计算各设计要素影响权重,得出设计优先级与设计策略。结论构建了基于APEC模型与结构方程模型的用户体验设计框架,并将其应用于大学生在线学习平台设计中,提升平台的用户体验水平,为相关用户体验设计研究提供一定理论参考。

Solvability Results on a Set-valued Input-output Equation

A class of set-valued Leontief input-output equation is introduced and two solvability theorems are obtained, which provide some corresponding existence, surjection as well as continuity results.

Solution of Nonlinear Stochastic Langevin’s Equation Using WHEP, Pickard and HPM Methods

This paper introduces analytical and numerical solutions of the nonlinear Langevin’s equation under square nonlinearity with stochastic non-homogeneity. The solution is obtained by using the Wiener-Hermite expansion with perturbation (WHEP) technique, and the results are compared with those of Picard iterations and the homotopy perturbation method (HPM). The WHEP technique is used to obtain up to fourth order approximation for different number of corrections. The mean and variance of the solution are obtained and compared among the different methods, and some parametric studies are done by using Matlab.

Alternating Segment Explicit-Implicit and Implicit-Explicit Parallel Difference Method for Time Fractional Sub-Diffusion Equation

The fractional diffusion equations can accurately describe the migration process of anomalous diffusion, which are widely applied in the field of natural science and engineering calculations. This paper proposed a kind of numerical methods with parallel nature which were the alternating segment explicit-implicit (ASE-I) and implicit-explicit (ASI-E) difference method for the time fractional sub-diffusion equation. It is based on the combination of the explicit scheme, implicit scheme, improved Saul’yev asymmetric scheme and the alternating segment technique. Theoretical analyses have shown that the solution of ASE-I (ASI-E) scheme is uniquely solvable. At the same time the stability and convergence of the two schemes were proved by the mathematical induction. The theoretical analyses are verified by numerical experiments. Meanwhile the ASE-I (ASI-E) scheme has the higher computational efficiency compared with the implicit scheme. Therefore it is feasible to use the parallel difference schemes for solving the time fractional diffusion equation.

Accounting for Quadratic and Cubic Invariants in Continuum Mechanics–An Overview

The differential equations of continuum mechanics are the basis of an uncountable variety of phenomena and technological processes in fluid-dynamics and related fields.These equations contain derivatives of the first order with respect to time.The derivation of the equations of continuum mechanics uses the limit transitions of the tendency of the volume increment and the time increment to zero.Derivatives are used to derive the wave equation.The differential wave equation is second order in time.Therefore,increments of volume and increments of time in continuum mechanics should be considered as small but finite quantities for problems of wave formation.This is important for calculating the generation of sound waves and water hammer waves.Therefore,the Euler continuity equation with finite time increments is of interest.The finiteness of the time increment makes it possible to take into account the quadratic and cubic invariants of the strain rate tensor.This is a new branch in hydrodynamics.Quadratic and cubic invariants will be used in differential wave equations of the second and third order in time.

R1233zd(E)制冷剂CPA状态方程

R1233zd(E)属于氢氟烯烃类(HFOs)物质,是一种新型替代制冷工质。为更加精确地描述其热力学性质,以CPA状态方程为基础,利用文献公开报道的R1233zd(E)的饱和液相密度、饱和气体密度及饱和蒸气压测量数据,拟合获取到CPA状态方程的5个参数。基于MATLAB,实现了利用CPA状态方程计算工质的热力学性质。研究结果表明:CPA状态方程在求解饱和气相密度时,精度与SRK方程相比有所降低;计算饱和液体密度和单相液体密度时的精度显著提升。

苏威肉鸽E系乳鸽和成年鸽体尺、屠宰性能比较及相关性分析

为探究不同年龄段和性别苏威肉鸽E系体尺和屠宰性能的差异,以28日龄和成年苏威肉鸽E系为材料,测定体重、体尺和屠宰性状,对比分析各测定指标的差异,应用相关分析原理对苏威肉鸽E系的体重、体尺与屠宰性能间的相关关系进行分析,并建立回归方程。结果表明:28日龄乳鸽体重与成年公鸽体重存在显著差异。除体斜长、胸宽和胸深无显著差异外,其他各指标均存在不同程度的显著性差异。其中乳鸽龙骨长、胸角和胫长与成年公母鸽存在显著差异。成年鸽中公鸽体尺指标普遍高于母鸽。苏威肉鸽E系体尺与屠宰性能之间存在相关回归关系,经方差分析和回归系数显著性检验,显示回归方程显著。就回归方程而言,乳鸽的回归方程决定系数R2高于成年鸽。通过各性状的相关和回归分析,可间接估测其生产性能,从而简化对肉鸽生产性能的测定过程,加速育种进程。这一研究为利用苏威肉鸽E系的体尺性状预测屠宰性能提供了理论依据。

基于SEM的B2C电子商务信任评价模型及算法

消费者信任对B2C型电子商务的成功起着非常重要的作用。本文通过结构方程模型(SEM)原理构建了消费者网上信任度指数评估模型,在单位结构变量的约束下,考虑误差方差。推导了应用偏最小二乘(PLS)估计算法的模型最佳迭代初值,提高了计算速度,说明了算法的收敛性。由此模型可以分析评价指标体系的各结构变量之间、结构变量与观测变量之间的相关关系；文中进一步给出了电子商务信任度指数计算公式,从而可以更有效地分析消费者网上交易的信任度,以便采取有效措施促进电子商务的发展。

L—E—E方程在计算天然气物性中的应用

为了使输气管道能够稳定、安全、经济地运行,实现科学的调度和管理,有必要对输气管道输送工况进行研究。在输气管道运行压力达10 MPa 状态下,天然气的热物性参数若用理想气体状态方程进行分析计算,将会产生很大的误差。应用 L—E—E方程求解实际气体的压缩因子、实际气体密度、比热、绝热指数、焦耳—汤姆逊效应系数、熵、焓等参数并编制了计算软件。计算结果表明,应用 L—E—E方程计算天然气物性参数时,其计算精度高,能够较好地满足工程实际的需要。

交流示波极谱法中i_f～E曲线的研究(Ⅱ)——i_f～E曲线的理论公式

提出利用i_f～E曲线代替常用的dE/dt～E曲线的新的交流示波极谱法,并研究了该法的基本理论,推导出i_f～E曲线的理论公式。

基于SEM的电子商务物流配送服务对企业经营绩效的影响

企业经营绩效被视为现代企业控制体系的三大支柱之一。知识经济时代,电子商务已经成为企业发展的新契机。通过对网络评价数据统计分析,在艾瑞咨询公司评价体系的基础上构建了更贴近现实的电子商务物流配送三级评价指标体系。运用结构方程模型的理论进行实证研究,对有网购经历的人进行问卷调查,对调查的数据进行信度和效度检验,研究发现电子商务务环境下物流配送对企业经营绩效具有重要的影响。为提高顾客满意度和忠诚度,提升企业绩效,有针对性地提出了物流配送服务的发展对策。

基于GT&SEM方法的电子商务物流配送安全影响因素研究

为提高电子商务物流配送安全管理水平,促进电子商务繁荣发展,研究电子商务物流配送安全影响因素并采取有针对性的对策。依据扎根理论研究方法,通过既有研究、调研访谈及典型案例分析,对调研和搜集的数据资料依次进行开放性译码、主轴译码、选择性译码、理论饱和性检验等环节,建立电子商务物流配送安全影响因素指标体系;在此基础上,构建电子商务物流配送安全影响因素结构方程模型,设计问卷并收集有效问卷数据,运用?SPSS19.0?软件对数据进行处理和信效度检验,并采用?AMOS21.0?对模型进行检验和修正。最终结果表明,制度建设、安全设备、配送网络、规范操作、安全素质等因素对电子商务物流配送安全影响较大。

基于SEM的电子商务和信息管理与信息系统专业满意度研究——以云南农业大学经济管理学院为例

通过对云南农业大学经济管理学院电子商务和信息管理与信息系统两个专业的专业满意度进行调查,借助顾客满意度和忠诚度模型,分析影响专业满意度的因素,建立结构方程模型,运用AMOS软件拟合模型并进行检验。研究发现专业服务、课程设置、师资状况等方面的感知质量是影响学生对专业满意度的关键因素。提高大学生的专业满意度,要从提升专业师资状况、改善专业教学条件设备、优化专业课程设置等关键指标入手,加强对学生的专业指导,使学生明确专业发展目标,提高专业综合素养,从而增强就业信心。

Sylvester时变矩阵方程求解的终态神经网络算法

为了更好地提高收敛的速度和精度,提出一种终态神经网络(TNN)及其加速形式(ATNN)的求解方法。该网络求解方法具有终态吸引特性,能够在有限的时间内得到时变矩阵的有效解。相比于具有渐近收敛动态特性的神经网络,该神经网络方法具有有限时间收敛性,不仅能够改变收敛速度,而且能达到较高的收敛精度。将3种不同的神经网络方法用于求解时变Sylvester动态方程;同时,以终态神经网络求解二次优化问题,实现冗余机械臂Katana6M180有限时间收敛的重复运动规划任务。仿真结果验证了终态神经网络方法的有效性。