氚在305铝合金及其预生膜中渗透率的研究

文章叙述了氚在305铝合金及其预生膜中渗透率的测量方法,推导出计算氚在305铝合金及其预生膜中的渗透率的经验公式。实验结果表明氚在镀预生膜的铝中的渗透率低,在100-250℃铝表面镀层阻挡氚渗透效果极为明显,而且温度越高效果越显著。     

有机/无机复合透明耐磨薄膜的制备

以甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)水解聚合产物作为主要成膜物质,引入正硅酸乙酯(TEO S)水解产物硅溶胶作为无机增强物,调节两种混合溶液pH值,利用两者羟基之间的共缩聚反应在聚碳酸酯(PC)板表面制备有机/无机复合透明耐磨薄膜;采用TG/DTA、FT-IR、SEM及UV-V IS对成膜过程、薄膜性能与结构进行表征。结果表明,KH-570和TEO S水解聚合产物通过共缩聚反应在PC板表面形成带有有机基团的无机交联网络,基本骨架由S i-O-S i组成,经120℃热处理后,薄膜均匀致密,提高了PC板的耐磨性,并有一定的增透作用。     

氮化硼薄膜的脉冲激光沉积

用Ｑ开关ＹＡＧ激光器的１．０６μｍ的脉冲激光在硅及玻璃衬底上沉积了氮化硼薄膜。做了ＳＥＭ，ＸＲＤ，红外透射谱和紫外一可见透射谱等测试。确认为六方氮化硼（ｈ－ＢＮ）薄膜．并测出其禁带宽度、晶格常数等。     

基站电磁环境测试方法的比较与分析

GSM移动通信基站电磁辐射测量常用的方法有两种,一种是用频谱分析仪和定向天线进行测量,计算出辐射功率密度;另一种是用射频电磁辐射仪,可以直接读出辐射功率密度.对实际运行的基站,两种方法的测量结果不一致,通过在实验室的反复实验,分析出这两种测量方法的特点,找到了测量结果不一致的原因.电磁辐射的测量不仅要了解测量方法的特点,还要了解辐射信号的特性,才能给出恰当的测试结论.     

刀具涂层的分类与应用

提出了刀具涂层的分类方法,分析了涂层刀具的选择依据。     

高温激光测距传感器自动防护门设计

在高温激光测距传感器的前端,设计了一种自动防护门。测距时门打开,不测距时防护门能很快地自动关闭,以防止水雾、灰尘、氧化皮等进入传感器内影响传感器的正常使用。     

Microstructure and mechanical properties of quaternary Cr–Si–O–N films by a hybrid coating system

Quaternary Cr–Si–O–N films were deposited by a hybrid coating system using a Cr cathodic arc target and a Si sputtering target in an Ar/N₂/O₂ gaseous mixture. The influence of oxygen flux rate on the microstructure and properties of the Cr–Si–O–N films were investigated. The results indicated that the oxygen-free Cr–Si–N film exhibited nanocolumnar microstructure containing CrN nano columns and amorphous Si₃N₄ phase. The Cr–Si–O–N films exhibit equiaxed CrN nanocrystallites likely surrounded by amorphous SiO₂ and Si₃N₄ phases. Further increasing the oxygen content gives films containing Cr₂O₃ crystallites. The hardness first increases from 30 GPa for the Cr–Si–N film to a maximum value of approximately 50 GPa for the oxygen content of 16 at.% and then decreases for larger oxygen content. All the Cr–Si–O–N films exhibit low friction coefficient (0.22–0.26) and low residual stress (− 0.03–0.08 GPa). The influence of the oxygen content on the microstructure and mechanical properties of the Cr–Si–O–N films is discussed.     

双膜式和多管式磺化反应器传质系数的比较

通过对双膜和多管膜式磺化反应器传质系数的计算与分析比较,表明传质系数的决定性因素是三氧化硫的扩散距离,其传质系数与实际情况较接近。又根据传质系数建立了反应高度与反应率的关系,分析了产品质量差异的原因,以及多管膜式磺化反应器和双膜式磺化反应器差异的原因。     

STABILITY ANALYSIS FOR THE PREDICTION OF THE MINIMUM TEMPERATURE OF FILM BOILING

The stability of film boiling on a vertical, constant temperature wall is analyzed by a steady-state small perturbation method. It was found that large amplifications of the perturbations in the downstream direction are predicted when the vapor Reynolds number falls below a critical value, indicating a great tendency to collapse the vapor film. Using a relatively simple model for the film thickness, the minimum wall temperature required to sustain the vapor film is calculated. The results show a tendency which is in agreement with experimental observation. It is suggested, however, that using a more accurate model for the film thickness can lead to a good prediction of the minimum wall temperature and explain the large effect of liquid subcooling, system pressure, surface tension and other fluid properties.