小曲率轿车覆盖件拉深模设计

在分析小曲率轿车覆盖件成形特点的基础上，指出采用阶梯拉深是提高材料塑性变形、减少回弹的有效措施，并以一个典型零件——前盖外板为例，设计了其拉深J-艺补充面，并给出了有限元模拟结果以验证有效性。     

大学学科课程研究性教学模式的构建

大学学科课程研究性教学模式主要适用于专业核心课程的教学。它的核心理念是人本教学理念、权变中心理念、主体有序互动理念和发展性能力养成理念 ;主要方式是基本知识与经典理论交往式教学、课题研究汇报教学和课题研讨评点教学 ;目标指向是学生的发展性能力养成。     

FTSR薄板坯连铸连轧SS400钢板的组织与性能

研究了唐钢薄板坯连铸连轧线(FTSR)生产的4种不同厚度SS400钢板的显微组织和力学性能，井测定了钢板的应变硬化指数。实验结果表明：随钢板厚度的减小，其晶粒尺寸呈现出减小的趋势，该钢板具有较为优良的综合力学性能及较好的成形性。另外，通过对5．75mm厚SS400钢板的系列温度冲击实验发现，该钢板在-60℃时仍具有较好的韧性。     

Splash Splat to Disk Splat Transition Behavior in Plasma-Sprayed Metallic Materials

A variety of metallic powder particles were thermally sprayed onto the mirror polished metallic substrate surface and the effect of both substrate temperature and ambient pressure on the flattening behavior of the particle was systematically investigated. In the flattening behavior of the sprayed particle onto the substrate surface, critical conditions were recognized both in the substrate temperature and ambient pressure. That is, the flattening behavior changed transitionally on that critical temperature and pressure range, respectively. A transition temperature, T _t, and transition pressure, P _t, were defined and introduced, respectively for those critical conditions. The fact that the dependence of both transition temperature and transition pressure on the sprayed particle material had similar tendency indicated that the wetting of the substrate by the molten particles seemed to be a domination in the flattening. Three-dimensional transition curvature by combining both transition temperature and transition pressure dependence was proposed as a practical and effective controlling principle of the thermal spray process. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

基于曲率匹配和递归排序的自适应排样算法

为提高盘状毛坯的使用率,提出一种口腔修复加工中模型边界在盘状毛坯中的排样算法,主要包括边界匹配、多边形定位及递归排序.首先基于协方差矩阵及矩阵SVD分解算法对模型多边形进行分段,并采用等弧长曲线采样曲率匹配确定待匹配模型边界;然后依毛坯边界角度分布及沿圆周排样的思想确定模型轮廓的旋转和平移定位;最后提出一种基于包络率的递归排序算法,对在排样过程中发现的大孔洞可动态地调整排样顺序.实验结果表明,该算法可以处理不规则模型边界在任意形状毛坯中的排样,能有效地降低加工成本.     

Quantification model of proper curvature for large‐sized curved TVs

We present a feasible modeling method to estimate the proper curvature for large‐sized curved TVs. We especially focused on two factors – preference and perceived distortion – to be considered to determine the proper curvature. The preference includes a number of advantages that people expect to fulfill the possibilities of a more immersive image and sense of realism from curved display. On the other hand, the perceived distortion means the side effects that people can notice uncomfortable feeling caused by the shape of a curved one. In order to find out how two factors would be different as a number of conditions like curvature, size, and viewing angle change, a series of subjective assessments were conducted. The evaluation results show that both the preference and perceived distortion vary with the conditions considerably. We performed the statistical analysis based on the results and proposed the quantification model of proper curvature, which has higher preference and less perceived distortion, for various‐sized curved TVs.     

Coherent microscopy by laser optical feedback imaging (LOFI) technique

The application of the non-conventional imaging technique LOFI (laser optical feedback imaging) to coherent microscopy is presented. This simple and efficient technique using frequency-shifted optical feedback needs the sample to be scanned in order to obtain an image. The effects on magnitude and phase signals such as vignetting and field curvature occasioned by the scanning with galvanometric mirrors are discussed. A simple monitoring method based on phase images is proposed to find the optimal position of the scanner. Finally, some experimental results illustrating this technique are presented.     

When Disaster Strikes

The importance of securing data against the threat of natural disasters i s something most MIS managers don't realize until it's too late. This column describes how two fires and an earthquake adversely affected several companies that were unprepared, or only partially prepared, for such disasters. It also discusses disaster recovery measures some MIS executives believe their companies should strengthen not only to protect the data center but to reduce their employees risk of losing valuable informa- tion from office files.     

确定河流生态流量的几种湿周法比较

为比较不同湿周法在计算河流生态流量中的适用性,采用幂函数描述无量纲化的湿周～流量关系,利用曲率法、斜率法及多目标评价法中的线性加权和法、理想点法(尺度系数r分别取1,2,∞)、乘除法等7种方法计算河流生态流量。结果表明:曲率法的结果偏小;斜率法、理想点法(r=1)、线性加权和法的结果相同,且位于各方法的中间;另外3种多目标评价方法得到的河流生态流量大于斜率法等的结果,但湿周的增加比例明显小于流量增加比例。在湿周～流量关系符合幂函数关系时,利用斜率法或理想点法(r=1)、线性加权和法确定河流生态流量的方法是适宜的。     

基于曲面曲率和RLDA的3D掌纹识别方法

提出一种新的3D掌纹识别方法,利用掌纹曲面的3D曲率信息提高当前2D掌纹识别算法的精确度和鲁棒性。首先因曲率是3维物体的重要表征,能够与视点无关地表现曲面的局部形状,不管手掌发生旋转或者平移,曲率信息都是稳定的,因此提取3D掌纹的均值曲面曲率特征来刻画3D掌纹的曲面特征;继而获得3D掌纹映射到2D空间上的灰度图像——均值曲率图像(MCI);然后在获得的MCI上采用正则化的LDA(RLDA)方法来进行二次特征抽取,以消除传统线性判别分析(LDA)应用于识别时存在的小样本问题和优化准则函数并不直接与识别率相关等问题。实验结果表明,所提出的方法相比与传统的LDA、PCA、ICA、LPP等方法有更高的精度和速度。