Tunable water-based lubrication behavior of alkyl- and fluoroalkyl-silanes

In this paper,we report the tribological properties of self-assembled molecular(SAM) films of fluoroalkylsilanes and non-fluoroalkylsilanes,with different chain-lengths,adsorbed on Si substrate surfaces by covalent bonds.The SAM films were characterized using a universal ball-disk experimental tester in aqueous solutions.The substrate surface was examined by X-ray photoelectron spectroscopy(XPS),and the SAM films adsorbed on the Si surfaces were inspected by contact angle measurements and XPS.Lubrication studies revealed that several kinds of fluoroalkylsilanes had similar friction coefficients;the small differences were attributed to the chain flexibility.In contrast,differences in the aqueous lubrication properties of SAM films of non-fluoroalkylsilanes were clearly identified.It is suggested that substitution with fluorine atoms and the surface affinities of fluoroalkylsilanes contributed to redistribution of surface changes,causing variations in lubrication behaviors.     

溶胶-凝胶法制备(Bi, Nd)4Ti3O12铁电薄膜

采用溶胶凝胶法在Pt/Ti/SiO2/Si基片上制备了(Bi, Nd)4Ti3O12铁电薄膜.将薄膜分别进行每一层、每二层、每三层500 ℃空气中预退火10 min，分别称为样品a、b、c，最后都于氮气氛中680℃总退火半小时. 结果表明预退火工艺对薄膜的铁电性能影响很大.样品a、b的铁电性能(2Pr分别为47.8 μC/cm2和51.9 μC/cm2)远远高于样品c(2Pr = 28.7 μC/cm2).三组薄膜都呈现良好的抗疲劳特性.     

预退火工艺对Bi3.15Nd0.85Ti3O12铁电薄膜性质的影响

采用溶胶一凝胶法在Pt／Ti／SiO2/Si基片上制备了Bi3.15Nd0.85Ti3O12铁电薄膜。将薄膜分别进行每一层预退火、每二层预退火、每三层空气中500℃预退火10min，分别称为a．b、c组薄膜，最后都于氮气氛中680℃总退火0．5h。结果表明，预退火工艺对薄膜的铁电性能影响较大，而对取向基本没有影响。同时，a,b两组薄膜的铁电性能（2Pr分别为47．8μC／cm2。和51．9μC／cm2）远远优于c组薄膜的铁电性（2Pr=28．7 μC／cm2）。所有Bi3.15Nd0.85Ti3O12薄膜都呈现良好的抗疲劳特性。     

光学薄膜镀制技术的对比研究

本文介绍了两种光学镀膜真空淀积技术——离子辅助淀积和反应离子镀,并详述了近年来的应用及进一步的发展。     

激光与光学薄膜的相互作用机制

应用激光与光学薄膜作用产生的等离子体形貌,研究了该作用过程和机理,实验结果与之吻合。     

FeSi／Cu多层膜的磁性和磁光效应

用射频交流溅射法制备了具有不同层厚的ＦｅＳｉ／Ｃｕ多层膜系列样品。通过铁磁共振谱测量发现：当Ｃｕ层厚度（ｄＣｕ）小于１５Ａ时，ＦｅＳｉ层间发生交换耦合。室温饱和磁化强度测量发现：ｄＣｕ＜１５Ａ，磁化强度随ｄＣｕ减小而明显下降。磁光克尔谱测量则表明：ｄＣｕ＜１５Ａ时，谱线出现异常。将上述三个结果进行综合分析提出如下模型：ｄＣｕ＜１５Ａ，Ｃｕ层中传导电子被反向极化，并通过ＲＫＫＹ相互作用使ＦｅＳｉ层间     

南极瑞穗站大气光学特征研究

本文利用南极瑞穗站１９７９年太阳可见光波段直接辐射的分光测量和微气象观测资料＾［１－２］。分别计算了整层大气、分子大气、臭氧和气溶胶的散射和吸收所构成的光学厚度τｔ（λ）、τＲ（λ）、τ０３（λ）和τａ（λ）及埃斯屈朗浑浊度系数β和波长指数ａ，并与北京和拉萨的相应值进行了比较＾［３－５］。文中对波长指数和埃斯屈朗浑浊度系数及整层大气垂直光学厚度与大气稳定度参数、湍流热通量的关系也进行了讨论。     

氢化纳米硅薄膜的光声光谱研究

分析了纳米硅薄膜材料从可见光到近红外范围的光声光谱，并与微晶硅和非晶硅材料进行了对比．纳米硅的光吸收系数比后两者都高（特别是在１．４～１．９ｅＶ之间，高出近一个数量级），其原因是纳米硅薄膜中大量晶粒对光子的散射、晶粒界面缺陷的吸收及载流子吸收的影响，此外，纳米硅光声谱中Ｕｒｂａｃｈ边宽且缓，反映出这种材料很高的无序程度．