基于LabVIEW的三传声器声速测量方法研究

提出了一种新的声速测量方法,通过测量管道壁面上3个固定位置的声压求解出声速。以LabVIEW软件为测量分析平台,建立声速测量系统,测得当前介质在不同频率处的声速。与理论的声速计算值比较,测量结果验证了测量方法的正确性。     

NiCr薄膜微加热器在低温环境下的电学特性研究

设计了一种适用于深低温环境的微型加热器。使用AC磁控溅射技术将NiCr(80/20 at.%)合金沉积到SiO2/Si基底上,并采用微加工工艺实现薄膜图形化,作为加热器的加热元件。研究了NiCr薄膜的电学性能和晶体结构与退火条件之间的关系。实验表明:在450℃氮气环境下退火30min,可以获得深低温性能优良的NiCr加热器。该加热器在20K时的电阻温度系数(TCR)为80.80×10-6/K。X射线衍射(XRD)分析显示NiCr薄膜在450℃氮气环境下退火后,薄膜的结晶度增大,因此,退火条件对薄膜的电阻率和电阻温度系数有较大的影响。     

基于无线疲劳监测系统的铝合金材料疲劳损伤研究

铝合金材料具有重量轻、强度高等特点,是国民经济发展的重要基础材料,在诸多领域(如飞行器设计与制造、建筑装饰等)中占有十分重要的地位。然而,其抗疲劳性能较差,在交变荷载作用下容易产生疲劳裂纹和发生疲劳破坏。提出了一种基于无线疲劳监测系统的铝合金材料疲劳损伤研究方法,实时监测了铝合金构件的疲劳应变,并实时分析了构件的疲劳损伤状况,为研究铝合金材料的疲劳性能提供了可借鉴性的方法。     

注塑级PVC／ABS合金的性能及其加工

阐述了注塑用聚氯乙烯/丙烯腈-丁二烯-苯乙烯共聚物(PVC/ABS)合金的制备工艺以及合金组成与冲击强度和屈服应力的关系,分析了影响注塑工艺条件的因素,并对体系的热稳定性和流变特性及其影响因素也作了简要的论述。     

镁铝合金阳极氧化表面处理工艺研究

研究了镁铝合金的阳极氧化过程,通过表面处理、化学清洗(脱脂除油)、碱蚀、化学抛光、电解着色、水合封孔、清洗和干燥等过程,得到符合国家标准的镁铝合金成品。     

基于Cortex M3的铝型材生产全自动牵引切割系统的研究与设计

分析了铝型材生产中对牵引切割的技术要求,建立了双牵引机运动模型,并根据该模型设计了一种基于Cortex M3的无双线牵引机控制系统,设计了硬件电路,编写相应的控制程序及设计了无线通信协议,使该系统具有良好的兼容性。该系统完全实现了双牵引机运动模型,并在某铝材生产厂家运行测试。试验证明,该系统完全符合厂家的要求,而且价格低廉,结构简单,性能稳定,具有良好的应用前景。     

无线传感器网络技术在炮口冲击波测试中的应用

炮口冲击波现场试验中测点分布数量较多且相对分散,且对测试仪器机动性要求较高,针对该问题,将无线传感器网络技术应用其中,不仅能提高测试系统的上下电灵活性,而且为整个测试系统提供了统一时基。重点介绍了系统无线模块的电源管理模块智能化设计和无线传感网络的工作流程,并且对测试系统的无线同步性进行实验室激波管校准试验和现场火炮实测试验。试验结果表明:将无线传感器网络技术应用于炮口冲击波测试,可以使仪器操作更简单,提高测试系统的机动性和测试效率。     

Condensed combustion products of aluminized propellants. IV. Effect of the nature of nitramines on aluminum agglomeration and combustion efficiency

The condensed combustion products of two model propellants consisting of ammonium perchlorate, aluminum, nitramine, and an energetic binder were studied by a sampling method. One of the propellants contained HMX with a particle size D ₁₀ ≈ 490 μm, and the other RDX with a particle size _{D 10} ≈ 380 μm. The particle-size distribution and the content of metallic aluminum in particles of condensed combustion products with a particle size of 1.2 μm to the maximum particle size in the pressure range of 0.1–6.5 MPa were determined with variation in the particle quenching distance from the burning surface to 100 mm. For agglomerates, dependences of the incompleteness of aluminum combustion on the residence time in the propellant flame were obtained. The RDX-based propellant is characterized by more severe agglomeration than the HMX-based propellant — the agglomerate size and mass are larger and the aluminum burnout proceeds more slowly. The ratio of the mass of the oxide accumulated on the agglomerates to the total mass of the oxide formed is determined. The agglomerate size is shown to be the main physical factor that governs the accumulation of the oxide on the burning agglomerate. __________ Translated from Fizika Goreniya i Vzryva, Vol. 42, No. 4, pp. 78–92, July–August, 2006.     

Passivation and pitting corrosion of nanostructured Sn-Ni alloy in NaCl solutions

The passivation and pitting corrosion of tin-nickel alloy (34% Ni-66% Sn) in NaCl solution was studied using potentiodynamic, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques complemented by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of concentration of the chloride ion, the switching potential, scans rate and pH on the electrochemical behavior of Sn-Ni alloy is discussed. The data indicate that the corrosion rate and the pitting corrosion of Sn-Ni alloy increases by the increasing of chloride ion concentration. The observed corrosion resistance of electrodeposited Sn-Ni alloy is due to the formation of a thin passive film from tin and nickel oxides.     

分离式双管板列管换热器的设计与制造

论述了双管板换热器材料选择、管板胀管槽等结构的设计、双管板检漏设计、最佳胀管压力计算等 ,以及双管板制造中内侧管子管板液压强度胀接、外侧管子管板强度焊接、双管板间空腔内和管子管板焊接接头气密性试验的要求