聚合物成型加工微型实验——聚氯乙烯棒材的挤出成型和测试表征

提出了聚合物成型加工实验微型化的设想,阐述了对聚合物成型加工微型实验的内涵和设计背景等的理解。详细介绍了自行设计的"聚氯乙烯棒材的挤出成型和测试表征"微型实验的教学目标、教学内容、实验用微型化装置与设备以及教学效果等。对化学专业本科生开设聚合物成型加工微型实验是一种有益的探索与尝试。     

挤出吹塑中型坯自由吹胀的动力学分析

聚合物挤出吹疗程 型坯的自由吹胀受到多方面因素的影响。采用动力学方法对此进行了研究。模拟了史胀过程听型坯轮廓变化， 吹胀压力，材料模量，型坯初始壁厚对此过程的影响。     

应用XMAC测井资料分析油田套损区岩石力学特征

本文应用萨中开发区北一区断东中块XMAC交叉式多极子阵列声波测井资料,认识了的标准层部位和油层部位的岩石力学分布特征,描述了地应力及岩石力学参数与套管损坏之间的相关性,为实现油田开发与套管防护双赢提供了一定技术支持。     

注聚平台振动特性及阻尼基座隔振性能

基于Abaqus软件建立大型注聚泵作用下注聚平台动力响应分析模型，探究注聚泵布置方式、开启数量、启动间隔等参数对注聚平台振动特性的影响规律。基于被动隔振原理提出一种迷宫式约束阻尼隔振基座用于降低平台的振动，并采用数值方法对该约束阻尼隔振基座的隔振效率进行研究。结果表明，注聚平台的振动响应会随着注聚泵开启数量的增加呈现线性增长趋势，不同启动间隔可导致注聚泵机振动载荷相互抵消，从而导致注聚平台振动响应大幅降低，而迷宫式约束阻尼隔振基座可显著降低注聚平台多个自由度的振动响应，其隔振效率可达20%。     

一种新型定差式恒流量注水堵塞器

针对常规注水堵塞器难以达到油田注水井定量注水要求以及阀门、水嘴寿命短的问题,研制开发了一种新型定差式恒流量注水堵塞器。这种恒流量注水堵塞器通过定差减压与可变节流的共同作用,在注水井的进口压力或地层压力发生变化的情况下可以维持注水量恒定,保证了注水层面配水一次到位,缩短了配水周期。这种恒流量注水堵塞器的阀门及水嘴采用抗冲击、耐磨材料制成,具有寿命长、可更换的特点。打捞部分结构及外形尺寸与通用的配水器相同,可直接用于井下偏心分层注水系统,无须改动系统的其他部件。     

Flowrate effects on the lateral coalescence of two growing bubbles

The coalescence of two growing bubbles presents unique characteristics compared to static bubble coalescence. The gas injection flowrate significantly affects the different stages of bubble evolution, which is poorly understood. In this study, we investigate the flowrate effects on the lateral coalescence of two growing bubbles experimentally. The synchronous bubbling from adjacent needles is achieved using water to push air. During the bubble growth process, we find that the initial nonlinear evolution of bubble volume is because the bubble emerges as a small spherical cap with a large curvature radius and apparent contact angle. As the neck expands after bubble coalescence, the injection flowrate accelerates the neck evolution compared to the case without air injection. We find the neck expansion time decreases linearly with increasing flowrate, while the expansion speed increases with flowrate, but only in the early stage. Moreover, we propose a new theoretical expression that predicts the neck radius well at all the flowrates. At the post-coalescence oscillation stage, the average projection area of the coalesced bubble increases linearly with time, except for periodic oscillations. Besides, we find that the injected air primarily influences the coalesced bubble's height, which in turn affects the projection area.     

梧州桂江三桥钢管拱混凝土压注施工技术

梧州桂江三桥钢管拱混凝土压注施工是全桥施工中的一个重要组成部分，高温地区配合比及压注方法的设计，保证了钢管拱混凝土的压注质量。     

Space and time resolved surface temperature distributions in Si power diodes operating under self-heating conditions

In order to optimize and improve the design of power devices with improved surge current safe operating area it is necessary to obtain a good correlation between measured and simulated space and time resolved temperature distributions. Therefore, an IR microscope capable of measuring the space and time resolved surface temperature distributions in Si power diodes operating under self-heating conditions has been developed. The minimum detectable spot size is 15 μm, while the signal rise time is detector limited to about 1 μs. The lower temperature detectivity limit is about 10°C over room temperature.

Using this instrument dynamic thermal phenomena in fast recovery 3.3 kV Si power diodes having radiation-induced recombination centers [Proceedings of the 7th EPE, Trondheim, 1997] subjected to 1.2 ms 400–2000 A/cm² and 0.3–2 ms 2000 A/cm² current pulses have been studied. The experimental results have been compared to results from 2D device simulations including surface recombination and carrier lifetime temperature dependence. The agreement between experimental and device simulation results (i.e. dynamic IV characteristics and time and space resolved temperature distributions) is very good up to a peak current density of 1500 A/cm², and a reasonable good one for peak current densities up to 2000 A/cm² (1.2 ms current pulses).     

Novel deprocessing technique for failure analysis of flip-chip integrated circuit packages

A novel technique for flip-chip package deprocessing that allows for detailed failure analysis of internal flip-chip packaging structures and chip circuitry has been developed. A systematic approach of selective wet etching and plasma etching is utilized. Understanding of package level reliability can be greatly enhanced with the capability to systematically access and examine defects in three-dimensions with powerful analytical tools such as the SEM/EDS. Additionally, the ability to inspect large areas of internal packaging structures, e.g., solder bump array, in three-dimensions makes it faster and more convenient to locate defects, compared to two-dimensional techniques such as progressive cross-sectioning. Case studies involving defects in solder bumps, underfill material, and substrate metallization are presented.     

Integrated process simulation of primary shaping: multi scale approaches

We investigate simulation approaches for the modelling of the primary shaping processes micro powder injection moulding and micro casting. We could reproduce the segregation during micro powder injection moulding (MicroPIM) with a simulation using particle methods. The phase field method allows for accurate prediction of the dynamics of solidification of a melt, whereby model order reduction is used to limit the computational effort. The results give valuable advice for the process conduct and the dimensioning of the micro parts.