51CrV4蝶形弹簧的机械镀锌工艺

釆用4种不同施镀工艺在51CrV 4蝶形弹簧表面制备了4种镀锌层,采用目测法观察镀层的外观及镀层覆盖完整情况,采用硫酸铜试验测试分析镀层厚度的均匀性,采用划格试验法测试镀层的结合强度。结果表明:保持性活化剂+沉积性活化剂施镀和复合活化剂施镀制备的镀层均存在一定缺陷,工件表面有漏镀、镀层不完整,并且镀后蝶形弹簧边缘镀层容易脱落。通过硫酸铜置换铜层后,使得基体表面的成分改变,不易析出杂质,保持洁净,改善了锌粉颗粒在基体表面的沉积效率以及镀层与基体之间的结合强度,减少了漏镀和镀层脱落,获得了覆盖更为完整、厚度均匀的镀层,镀层的耐腐蚀性得到提高。对闪铜后施镀的两种镀层进行对比,复合活化剂施镀镀层粗糙,但结合相对较好,施镀过程也更简便。对基体经硫酸铜置换铜层后再进行施镀所得的两种镀层进行比较。

共底贮箱氢氧泄漏监测设备研制

本文介绍了共底贮箱氢氧泄漏监测设备的详细结构设计,包括共底抽真空装置、共底气体成分分析装置、发射现场抽空管路和现场使用流程优化等内容。目前,所研制的2套共底氢氧泄漏监测设备已顺利交付使用,并已参与了3次发射任务,确保了火箭发射任务期间的航天器安全和发射人员人身安全,未来将持续服务于新一代中型运载火箭高密度发射任务。

镀锌层硅酸盐+虫胶复合转化膜的制备和表征

目的阻碍热镀锌板出现白锈,提高镀锌层的耐腐蚀性能。方法采用正交试验法优化出添加虫胶水溶液的有机无机复合钝化液。通过电化学Tafel极化曲线、交流阻抗(EIS)、乙酸铅点滴和中性盐雾试验,对比分析基体、硅酸盐+虫胶复合钝化膜与铬酸盐钝化膜的耐腐蚀性能。采用摩擦法测试对比分析基体和无铬钝化膜试样的附着性能,并通过扫描电子显微镜、X射线光电子能谱和红外光谱对形貌和结构进行分析。结果添加虫胶水溶液的复合钝化膜表面平整致密,72 h中性盐雾试验后的腐蚀面积小于10%。乙酸铅点滴试验和电化学测试显示,复合钝化膜的耐腐蚀性能较基体好。附着力试验测试显示,复合钝化膜具有良好的附着能力。结论因为复合钝化液中的虫胶与硅酸盐交织为O—Si—CH_2结构,与金属离子结合生成致密的膜层附着在镀锌层表面,使得复合钝化膜致密平整,且使腐蚀过程得到了强烈的抑制。

镀锌层无铬钝化的研究进展及性能检测

概述了国内外镀锌板无铬钝化技术的研究现状与进展,介绍了单一无机钝化、有机钝化、有机无机复合钝化的防腐蚀机理以及技术发展;总结了钝化条件对钝化膜外观和防腐蚀性能的影响,详细阐述了有机物+无机盐、硅烷+有机酸或有机树脂以及硅烷+有机物+无机盐的复合钝化技术,并对比分析了上述不同钝化技术的优缺点。总结了钝化耐蚀性检测及评价标准及具体检测方案。根据有机无机复合钝化耐腐蚀机理及试验数据,有机和无机复合钝化有希望代替铬酸盐钝化。展望了有机提取材料钝化技术的发展前景,指出天然提取有机物植酸、虫胶和单宁酸与无机物复合钝化是发展方向之一。

Influences of Injection Barrier and Mobility on Recombination Rate and Zone in OLEDs

The luminous efficiency of organic light-emitting devices depends on the recombination probability of electrons injected at the cathode and holes at the anode. A theoretical model to calculate the distribution of current densities and the recombination rate in organic single layer devices is presented taking into account the charge injection process at each electrode, charge transport and recombination in organic layer. The calculated results indicate that efficient single-layer devices are possible by adjusting the barrier heights at two electrodes and the carrier mobilities. Lowering the barrier heights can improve the electroluminescent(EL) efficiency pronouncedly in many cases, and efficient devices are still possible using an ohmic contact to inject the low mobility carrier, and a contact limited contact to inject the high mobility carrier. All in all, high EL efficiency needs to consider sufficient recombination, enough injected carriers and well transport.

Recombination Efficiency and Width in Bilayer Organic Light-emitting Devices

A bilayer model with ohmic anode contact and injection limited cathode contact has been proposed to calculate the recombination efficiency and recombination zone width of the device. The effects of the thickness of hole transport layer and the barriers of organic/organic interface on the combination efficiency and recombination width have been discussed. It is found that： （1） When the electrons are blocked fully and the holes are not blocked significantly at the organic/organic interface, for a given Lh/L, the recombination efficiency increases with increasing the applied voltage, but at a higher applied voltage, the recombination efficiency decreases with increasing Lh/L; （2） The recombination efficiency increases with increasing applied voltage and Hh＇, and when applied voltage and Hh＇ exceed some value, the recombination efficiency appears as a plateau; （3） The recombination width decreases with increasing the applied voltage and Lh/L. This model might explain the relative experiment phenomena.

基于射线技术的低压竖直管气液两相流模型研究

为解决油田开采末期因地层压力下降引起的含气率增加、气液速度差异变大而导致的气液两相流测量困难,本文采用文丘里管和射线传感器相结合的方法对竖直管自下而上流动方向的气液两相流进行了试验研究。其中射线传感器布置在文丘里的喉部,用于测量空隙率,而文丘里管用于测量两相流总流量。从均相流模型出发,结合Chisholm滑速比经验公式,提出了一种新的液相修正系数与空隙率的关联式。试验工质采用来自大庆油田产出的天然气、原油及地层水,试验压力为0.1~0.4 MPa,空隙率范围为34.5%~95.8%。根据试验结果,利用本文计算模型得到的液流量、气流量及气液总流量的均方根误差分别为3.4%、9.6%和3.2%。与利用滑速比计算液相修正系数的Zhang模型进行对比,本文的模型计算得到气量结果明显更优,表明空隙率可以更好地表征低压力下气体流量变化,为工业应用提供一种新的计算思路。