Evolution of insoluble eutectic Si particles in anodic oxidation films during adipic-sulfuric acid anodizing processes of ZL114A aluminum alloys

The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were in-vestigated by optical microscopy (OM) and scanning electron microscopy (SE...     

Modeling electric vehicle’s following behavior and numerical tests

The micro modeling for electric vehicle and its solution were investigated. A new car-following model for electric vehicle was proposed based on the existing car-following models. The impacts of the electric vehicle＇s charging electricity were studied from the numerical perspective. The numerical results show that the electric vehicle＇s charging electricity will destroy the stability of uniform flow and produce some prominent queues and these traffic phenomena are directly related to the initial headway, the distance between two adjacent charging stations and the number of charging stations. The above results can help traffic engineer to choose the position of charging station and the electric vehicle＇s driver to adjust his/her driving behavior in the traffic system with charging station.     

高斯曲率内蕴公式的几种形式的推导方法

考虑曲面上高斯曲率内蕴公式的表示问题,运用曲面基本方程的矩阵表示法,给出了高斯曲率是内蕴量的直接的显式公式,并指出这种内蕴公式与Brioschi的表示公式是明显一致的;给出了高斯曲率简化公式的推导来源,揭示出了高斯曲率隐式公式的发现过程.     

Creep behavior and failure mechanisms of CVI and PIP SiC/SiC composites at temperatures to 1650 °C in air

Creep properties of 2D woven CVI and PIP SiC/SiC composites with Sylramic™-iBN SiC fibers were measured at temperatures to 1650 °C in air and the data was compared with the literature. Batch-to-batch variations in the tensile and creep properties, and thermal treatment effects on creep, creep parameters, damage mechanisms, and failure modes for these composites were studied. Under the test conditions, the CVI SiC/SiC composites exhibited both matrix and fiber-dominated creep depending on stress, whereas the PIP SiC/SiC composites displayed only fiber-dominated creep. Creep durability in both composite systems is controlled by the most creep resistant phase as well as oxidation of the fibers via cracking matrix. Specimen-to- specimen variations in porosity and stress raisers caused significant differences in creep behavior and durability. The Larson-Miller parameter and Monkman-Grant relationship were used wherever applicable for analyzing and predicting creep durability.     

Photocatalytic oxidation activity of titanium dioxide film enhanced by Mn non-uniform doping

1 Introduction Heterogeneous photocatalysis is an effective technique for reducing the concentration of pollutants at low concentration. It has been demonstrated that almost all organics can be oxidized to generate carbon dioxide, water and simple mineral…     

Pressure sintering of W-15wt.%Cu alloys prepared by mechanical alloying as a subsequent densification treatment method

1. Introduction W-Cu alloys are widely used in many fields due to their superior properties [1]. With the rapid de-velopment of technology, more demands are being made on the W-Cu alloys. For instance, higher heat conductivity, lower thermal expansion coefficient, and more rigorous air tightness are required when these alloys are used for electronic package materi-als, such as heat sink materials. Especially, the re-quirement of more rigorous air tightness means that the W-Cu alloys must pos…     

CAS wavelet method for solving the fractional integro-differential equation with a weakly singular kernel

In this paper, a computational method for numerical solution of a class of integro-differential equations with a weakly singular kernel of fractional order which is based on Cos and Sin (CAS) wavelets and block pulse functions is introduced. Approximation of the arbitrary order weakly singular integral is also obtained. The fractional integro-differential equations with weakly singular kernel are transformed into a system of algebraic equations by using the operational matrix of fractional integration of CAS wavelets. The error analysis of CAS wavelets is given. Finally, the results of some numerical examples support the validity and applicability of the approach.     

大数据负载的体系结构特征分析

针对大数据离线分析类和交互式查询类负载,首先对这些负载的一些共性进行分析,提取出公共操作集,并对它们进行分组整理;然后在大数据平台上测试这些负载运行过程中的微体系结构特征,采用PCA和SimpleKMeans算法对这些体系结构特征参数进行降维和聚类处理。实验分析结果表明负载之间有公共的操作集,如Join和Cross Production;有些负载有相似的属性,如Difference和Projection共享相同的微体系结构特征。实验结果对于 处理器等硬件平台的设计以及应用程序的优化具有指导性的意义,并且为大数据基准测试平台的设计提供了参考。     

基于本体的飞机设计知识组织模型

为了解决飞机设计中知识信息量大和表现形式多样的问题,提出了一种基于本体的知识组织模型构建方法.起初论述了知识组织和本体的有关概念,然后在此基础上提出基于本体的ABC反馈方法,并构造飞机设计知识模型来验证研究成果的正确性和有效性,同时描述了基于本体构建知识模型的优点.     

大规模流体场景的真实感与实时模拟

目的 基于物理的流体动画模拟是计算机图形学领域中的研究热点,针对实际应用中仍难以实现大规模流体场景的真实感与实时模拟,提出了基于shallow water方程的物理模拟方法。方法 首先,给出shallow water方程的稳定欧拉数值求解方法,解决模拟过程中存在的毛刺、陡坡水滴斑点等数值求解的不稳定性问题;其次,提出刚体和粒子系统与流体高度场的稳定耦合模型,实现双向固流耦合和流体表面细节的真实感模拟;最后,设计高度场的多精度网格算法以及粒子的隔点采样方法,加速大规模流体的物理模拟计算。结果 实验结果表明,本文方法解决了传统欧拉方法求解shallow water方程的流体模拟过程中存在的不稳定和计算复杂等问题,在300×300网格分辨率和2.2×10⁴粒子数的规模下,达到了20帧/s的实时模拟速度。结论 本文算法具有良好的高效性和稳定性,适用于电子游戏和视景仿真等实时应用领域中的大规模流体场景的真实感模拟。