Melting,crystallization behaviors,and nonisothermal crystallization kinetics of PET/PTT/PBT ternary blends

The melting, crystallization behaviors, and nonisothermal crystallization kinetics of the ternary blends composed of poly(ethylene terephthalate), poly(trimethylene terephthalate) (PTT) and poly(buthylene terephthalate) (PBT) were studied with differential scanning calorimeter (DSC). PBT content in all ternary blends was settled invariably to be one‐third, which improved the melt‐crystallization temperature of the ternary blends. All of the blend compositions in amorphous state were miscible as evidenced by a single, composition‐dependent glass transition temperature (T_g) observed in DSC curves. DSC melting thermograms of different blends showed different multiple melting and crystallization peaks because of their various polymer contents. During melt‐crystallization process, three components in blends crystallized simultaneously to form mixed crystals or separated crystals depending upon their content ratio. The Avrami equation modified by Jeziorny and the Ozawa theory were employed to describe the nonisothermal crystallization process of two selected ternary blends. The results spoke that the Avrami equation was successful in describing the nonisothermal crystallization process of the ternary blends. The values of the t_1/2 and the parameters Z_c showed that the crystallization rate of the ternary blends with more poly(ethylene terephthalate) content was faster than that with the lesser one at a given cooling rate. The crystal morphology of the five ternary blends investigated by polarized optical microscopy (POM) showed different size and distortional Maltese crosses or light spots when the PTT or poly(ethylene terephthalate) component varied, suggesting that the more the PTT content, the larger crystallites formed in ternary blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

基础影响下车载飞轮电池动态性能的联合仿真分析

以车载飞轮电池为研究对象,利用ADAMS软件建立了飞轮转子与等效基础的机械模型,并利用MATLAB软件建立了相应的不完全微分PID控制器模型.通过联合仿真分析了基础的加速、减速、转弯和爬坡运动,以及因路面不平整引起的基础纵向振动、横向振动和俯仰振动对高速飞轮转子系统动态性能的影响.仿真结果表明,基础的不同运动状态均会对高速飞轮转子的稳定运行产生显著影响,仿真分析结果可对车载飞轮电池的设计提供有益参考.     

移动混合开发框架

针对现有混合开发框架在开发便利性和应用性能方面的不足,研究了以HTML5开发为基础的移动混合开发框架的问题.结合HTML5跨平台特性、打包机制、多窗口管理机制、原生插件开发技术等,实现了一套自有的混合开发框架.本混合开发框架为开发带来了便利,提升了开发效率,同时,混合引擎中独特实现的Widget应用管理以及窗口管理模式也改善了混合应用的性能,提升了用户体验.我公司实现的企业级移动解决方案表明该框架性能较好,易于使用,具有较好的商业价值.     

基于频域的运动模糊参数估计

运动模糊图像复原的关键之一是模糊核函数的估计,即降质图像的模糊方向和距离变化的估计。已经有多种方法用于模糊核函数的估计,通过对运动模糊图像频谱的研究,提出了一种基于形态学的模糊运动方向计算方法,并根据模糊图像频谱的黑色条纹周期出现的规律,采用投影法计算极值点,从而获取模糊运动距离。实验结果表明该算法简单有效,得到的运动模糊参数较准确。     

基于隶属函数的骆岗机场新型大雾预报方法

准确预报大雾对机场减少航班大面积延误和旅客滞留有重要意义。本文阐述一种适用于机场的大雾短时预报方法。通过选取骆岗机场历史地面逐时观测气象资料,依据气温趋势不同类型,运用模糊隶属度与发生条件概率模型,分别建立短时大雾的预报方法。利用VC++程序开发了骆岗机场大雾短时预报软件,可扩展硬件构建实时预警系统。使用2011年地面资料检验结果显示:对未来3小时大雾预报准确率为91.3%,TS评分为0.84。因此,本文提出的大雾短时预报方法在骆岗机场附近3小时大雾预报中是有效的。     

小型图书管理系统的设计和实现

图书管理系统作为现代社会高校日常事务中不可或缺的一个IT系统,拥有悠久的历史传承。从其功能上看,它将图书工作人员从繁琐、杂乱的图书管理信息中解救出来,也使得读者能够更快捷全面的了解图书信息。作为软降工程的一个项目,小型图书管理系统实现了计算机的管理自动化。此系统,用C#开发前端界面和后台业务,用SQL作为数据库来存放读书信息。实现了信息管理、借还操作、图书排列及信息查询等多个必须功能。从结果上看前期工作已基本上满足日常图书管理工作的基本需求。     

三维动画技法分析及其对传统动画的冲击

近年来,计算机软件技术发展十分迅速,特别是在开发立体三维的软件上有了明显突破,现在市场上流行的三维制作软件使用范围非常广泛。在动画制作方面,立体三维制作的软件有3dsmax,maya,softimage,lightwave等等,从三维动画进入人们的视野开始,人们就开始喜欢上了它。三维动画的出现对行业内的二维动画有一定的冲击。本文就三维动画的技术和在行业内的影响力做具体分析。     

基于UC/GUI的嵌入式GUI在S3C 2410上的移植

嵌入式图形用户界面为嵌入式系统提供了人机交互界面,大大方便了嵌入式系统的人机交互,进而加速了嵌入式系统的流行。选择了基于UC/GUI的嵌入式GUI作为移植对象,并详细介绍了将其移植至S3C2410开发平台上的技术。该移植技术对于其他的嵌入式开发板也具有一定的参考价值。     

单幅图像多尺度小波深度提取算法

针对浅景深图像中平滑前景区域深度提取误差大的问题,基于像素点分类思想对深度值进行修正,提出一种基于多尺度小波线索的、可同时面向单幅浅景深图像和广角图像的深度图提取算法.首先使用小波分析法在多个尺度下提取图像深度信息;然后提出自适应分类法并根据尺度与深度变化规律对像素点做深度修正,得到深度图;最后结合区域生长与边缘分割算法对深度图进行区域优化.为了加快深度计算,还提出了快速zerocount法以及多尺度加速法来满足标清视频实时处理要求.实验结果证明,采用文中算法获得的深度图相对深度正确,前景和背景区域深度一致性好.     

Liquefaction of wood in the presence of phenol using phosphoric acid as a catalyst and the flow properties of the liquefied wood

The liquefaction of wood in the presence of phenol using phosphoric acid as a catalyst and the flow properties of the obtained liquefied wood were investigated. It was found that phosphoric acid is a satisfactory catalyst for liquefying wood. The amount of phenol that reacts with the liquefied wood components (i.e., combined phenol) increases with an increase in liquefaction temperature, liquefaction time, catalyst content, or liquid ratio. By removing the free phenol, the resulting liquefied woods become novolaclike resins. The measurements of the flow properties of these liquefied woods reveal that the melts of liquefied woods behave as pseudoplastics and their flows obey the Ostwald de Waele power law equation. The amount of combined phenol within the liquefied wood and the presence of filler in the liquefied wood have great influence on their flow properties. The flowing temperature, activation energy, and zero shear viscosity of the liquefied woods show tendencies to increase with an increase in combined phenol. © 1994 John Wiley & Sons, Inc.