激光多普勒动态位移测量系统信号处理方法的研究

为了实现远距离、非接触方式对爆炸容器的高速变形过程进行测量,项目研究了激光多普勒动态位移测量系统;但是随着试验任务要求的不断提高,现有激光多普勒动态位移测量系统一些技术指标(量程、分辨率)不能满足测试要求的现状,通过信号分析方法的研究,在不改变硬件的条件下,改进信号处理方法,重新研制数据处理系统,挖掘原系统的潜力,扩展原有测量系统的量程,并提高测量对象的分辨率;实验结果表明,该数据处理系统运行稳定可靠,检测精度高,其信号处理方法是可行的.     

析电子商务专业课程的实践能力体系教学改革

电子商务专业是一个综合性很强的专业,需要学生学习的专业课程众多,特别是实践能力要求很高的课程,每一门课程都需要学生掌握多个能力,且课程之间的关系密切。科学合理的进行教学改革有助于缩短学生在校学习和就业岗位需求能力的差距,提高学生的就业竞争力。     

气-液-固三相流化床

本文较系统地讨论了气-液-固三相流化床的研究现状,包括流动城、相含率、相闻质量传递、各相混合、热量传递特性和气泡行为等,同时指出了这一领域今后可能的发展趋势。     

系统集成环境下基于 STEP 的产品装配模型研究

系统集成是当今计算机应用发展的趋势，ＳＴＥＰ标准为我们进行有效的ＣＡＤ／ＣＡＰＰ／ＣＡＭ集成提供了新的途径。本文介绍了系统集成环境下基于ＳＴＥＰ的装配建模方法，提出了一面向产品整个生命周期的装配模型，并以减速器为对象建立了装配ＣＡＤ／ＣＡＰＰ集成系统。     

TEXTURE AND MECHANICAL PROPERTIES OF WARM ROLLED Fe_3Al BASED ALLOY

ＴＥＸＴＵＲＥＡＮＤＭＥＣＨＡＮＩＣＡＬＰＲＯＰＥＲＴＩＥＳＯＦＷＡＲＭＲＯＬＬＥＤＦｅ_３ＡｌＢＡＳＥＤＡＬＬＯＹＳＵＮＺｕｑｉｎｇ，ＭＡＯＷｅｉｍｉｎ，ＣＨＡＩＳｈｕｙａｎ，ＹＡＮＧＷａｎｇｙｕｅ，ＨＵＡＮＧＹｕａｎｄｉｎｇ（Ｕｎｉｖｅｒｓｉｔｙ...     

GTA Welds of Iron-Aluminide Based Alloys

The weldability of two Fe3Al-based intermetallic alloys and one Fe- 16%Al-based (atom fraction) alloy has been investigated for gas tungsten arc (GTA) welding on sheets with a thickness of 2 mm. The results indicated that pre-heating and post-annealing treatment were important procedures for retarding cold crack initiation and the proper selection of filler could effectively improve the weldability. For the same alloys with the same welding filler, it is better to choose lower welding current, in another word, lower heat input.     

Hot Tearing Characteristics of Binary Mg-Gd Alloy Castings

Hot tearing characteristics of Mg-xGd (x = 1, 2, 5 and 10 wt pct) binary alloys have been studied in a constrained rod casting apparatus attached with a load cell and data acquisition system. The onset temperature of the hot tearing was identified from the force drop in the force–temperature–time curve, and the corresponding onset solid fraction was obtained from the fraction solid–temperature curve derived using Scheil non-equilibrium solidification model. The results indicate that the onset solid fraction for the hot tear decreased as the Gd content increased. The susceptibility defined by the total tear volume measurements by the X-ray micro-tomography technique indicates that the susceptibility increased with increase in Gd content to reach a maximum at 2 pct and then reduced with further increase in Gd to reach a minimum with 10 pct Gd. The high susceptibility observed in Mg-2 pct Gd was attributed to its cellular or columnar grain structure, which facilitated easy tear propagation, high strain at the onset with little amount of remaining liquid. In contrast, the lowest susceptibility of Mg-10 pct Gd was related to its equiaxed grain structure, which effectively accommodated the strain during solidification by reorienting themselves and the ability of the Gd-rich liquid to partially or completely refill the tear at the end of solidification. The results also indicate that the increase in mold temperature [723 K (450 °C)] significantly reduced the total crack volume and hence reduced the susceptibility, which was attributed to the increase in the hot spot size and lesser total stain at the hot spot region.     

Experimental and numerical analysis of hot tearing susceptibility for Mg–Y alloys

The influences of Y content and initial mold temperatures on the hot tearing susceptibility (HTS) of binary Mg–Y alloys were investigated using a constrained rod casting (CRC) apparatus, which is equipped with a load cell and data acquisition systems. The hot crack formation was monitored during CRC experiments. The experimental results show that HTS first increases with increase in the Y content, reaches the maximum at about 1.5 wt% Y and then decreases with further increase in the content of Y. The severest of hot tearing is found in Mg–1.5 wt% Y alloy which is due to its large columnar grain structure, wide solidification range, and small amount of eutectic. The resistance to hot tearing is apparently improved by increasing the initial mold temperature. ProCAST simulation software was used to predict the hot tearing of Mg–Y alloys in CRC. The simulation results show a good agreement with the experimental measurements. The numerical simulations will be helpful and valuable to optimize the alloy composition and casting parameters to minimize the hot tearing defects.     

超重力场技术用于油田注水脱氧的工业研究

在超重机中做了用天然气对油田注水脱氧的工业试验。测试了气液比、处理水量、转速等对出口液氧含量、气体压降的影响。该试验机在设计能力５０ｍ￣３／ｈ下，供给９０ｍ￣３／ｈ的天然气，在９６０ｒ／ｍｉｎ，可将水中含氧从５－６ｍｇ／ｌ脱除至０．０５ｍｇ／Ｉ以下，可满足油田注水要求。经５００ｈ连续运转，超重机性能稳定，合乎工业要求。     

三相流化床和两相鼓泡塔内的压强径向分布

利用应变片压力传感器测定了三相流化床和气-液鼓泡塔内压强的径向分布,比较了不同操作条件下床层内不同轴向位置上压强径向分布的特征,初步探讨了体系的流体湍动特性。