Titanium‐implanted CaTiO3 films and their changes in Hanks' solution

Titanium‐implanted CaTiO₃ film was prepared and then characterized by x‐ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectrometry (RBS) before and after immersion in Hanks' solution for 7 days. An as‐prepared specimen contained a small amount of Ar implanted during sputtering, although the pressure was as low as 10^?4 Torr. Even though Ar convolution increased with an increase in the relative Ti ion dose, most of the convoluted Ar was not from the Ar gas used for Ti ion production but rather was from the Ar gas used for sputtering the CaTiO₃. During Ti implantation, the CaTiO₃ films were ion‐etched by Ti ions. The composition of the CaTiO₃ film was not changed to any great degree by the Ti implantation, however its properties changed considerably. After immersion in Hanks' solution, the thickness of the specimen not implanted with Ti decreased the most whereas the [Ca]/[P] ratio, which was nearly unity before exposure, decreased significantly, becoming 0.23 on the Ti‐implanted specimen prepared at 200 W and 0.13 on the Ti‐implanted specimen prepared at 50 W. It was also observed by XPS that the ratio [Ca]/[P] was ～1.9 for all Ti‐implanted specimens after immersion in Hanks' solution for 7 days. Judging from the binding energies of Ca 2p_3/2 and P 2p electrons and the [Ca]/[P] ratio, it was suggested that a hydroxyapatite‐like substance had formed on the surfaces of the Ti‐implanted specimens after immersion in Hanks' solution. Copyright © 2003 John Wiley & Sons, Ltd.     

基于表面阻抗边界条件的等离子体薄涂层电磁散射的时域有限差分分析

基于表面阻抗边界条件时域有限差分(FDTD)方法研究了一维斜入射情况下非磁化等离子体薄涂层涂敷金属材料的电磁散射特性, 该方法忽略对薄层背景材料进行网格剖分, 大大减少了计算量. 首先推导了理想导体涂敷等离子体薄涂层的表面阻抗频域表达式, 然后代入边界条件并变换到时域, 再用分段线性递推卷积方法将时域表达式离散得到FDTD迭代式. 编程计算了垂直及斜入射情形下的平行极化和垂直极化反射系数, 通过验证算例与解析解对比, 结果表明该方法的准确性和有效性. 最后利用该方法分析了不同入射角对反射系数的影响.     

激光二极管泵浦的高重复频率Nd：YAG激光器

报道两个１．５Ｗ连续激光二极管端面泵浦的声光调ＱＮｄ：ＹＡＧ激光器，输出激光脉冲的最高重复频率为３０ｋＨｚ重复频率１ｋＨｚ时，最窄脉宽为１２ｎｓ，最高峰值功率为１２．１ｋＷ。     

Iodate Sensing Electrodes Based on Phosphotungstate‐ Doped‐Glutaraldehyde‐Cross‐Linked Poly‐L‐lysine Coatings

Glassy carbon electrode modified with phosphotungstate‐doped‐glutaraldehyde‐cross‐linked poly‐L ‐lysine (PLL‐GA‐PW) film was employed for iodate determination. The PLL‐GA‐PW film electrode shows excellent electrocatalytic activity towards iodate reduction with significant reduction of overpotential. Under optimized experimental conditions, a linear range from 5×10^?8 to 2.27×10^?2 M with a sensitivity of 61.75 μA mM^?1 was obtained. Possible interfering species, in iodate determination, were evaluated and the applicability of proposed sensor for iodate estimation in table salt was also demonstrated. The PLL‐GA‐PW film electrode shows fast response, wider linear range, and good selectivity and stability.     

Effects of Co-addition of DBS and PEG on Wetting Performance of TiO_2 Film

Nanocrystalline anatase TiO2 films with indium tin oxide(ITO) coated glass as the film substrate were fabricated through spin-coating technique. The TiO2 pastes were prepared with sodium dodecylbenzenesulfonate(DBS) modified TiO2 nanocrystals, synthesized by sol-hydrothermal processes in advance, together with different amounts of polyethylene glycol(PEG) macromolecules. The as-prepared films were mainly characterized by ultraviolet-visible (UV-Vis) spectroscopy, field emission scanning electron microscopy(...     

运动黏度在FLC薄膜-白油固液复合润滑体系中的作用

利用直流等离子体沉积技术制备了含氢类富勒烯碳膜(FLC),在工业级白油润滑条件下考察了FLC薄膜润湿性、摩擦学特性和白油运动黏度对整个固液复合润滑体系的影响。研究结果表明:在5~150 mm~2/s的考察范围内,白油的运动黏度越小,其对FLC薄膜的润湿性越好;随着运动黏度的增大,白油分子量增加且分子链变长,在薄膜表面油膜吸附增强,油膜厚度增加,FLC薄膜摩擦系数逐渐减小,于32 mm~2/s时达到最小值(0.114),随着黏度进一步增大,过高的运动黏度增加了黏性阻力和摩擦阻力,FLC薄膜摩擦系数反而上升;同时,FLC薄膜的磨损率随黏度增大而减小,当黏度超过26 mm~2/s之后,变化幅度趋缓。     

Optimum packing density and crystal structure of tin-doped indium oxide thin films for high-temperature annealing processes

The influence of high-temperature annealing on the electrical properties and microstructure of tin-doped indium oxide (ITO) thin films was investigated as a function of oxygen gas flow ratio to argon gas during the sputtering deposition. The ITO thin films were annealed at 500 °C in air after the deposition. It was found that the ITO thin films, which were deposited in relatively low oxygen gas flow ratio, exhibited high Hall mobility and low-resistivity after the annealing. Furthermore, the X-ray reflectivity and diffraction measurement revealed that the ITO thin film with low-resistivity after annealing exhibited high packing density, smooth surface and low crystallization degree. It can be considered that the carrier electron scattering was suppressed with increasing in the packing density of the ITO thin film; as a result, the Hall mobility and resistivity were improved.     

分数维方法研究GaAs薄膜中的极化子

本文采用分数维方法, 在讨论Al_0.3Ga_0.7As衬底上GaAs薄膜的分数维基础上, 计算了GaAs薄膜中的极化子结合能和有效质量. 随着薄膜厚度的增加, 极化子结合能和质量变化单调地减小. 当薄膜厚度L_w<70 Å并且衬底厚度L_b<200 Å时, 衬底厚度的变化对薄膜中极化子的结合能和质量变化的影响比较显著, 随着衬底厚度的增加, 薄膜中极化子的结合能和质量变化逐渐变大; 当薄膜厚度L_w>70 Å或者衬底厚度L_b>200 Å时, 衬底厚度的变化对薄膜中极化子的结合能和质量变化的影响不显著. 研究结果为GaAs薄膜电子和光电子器件的研究和应用提供参考. 关键词： 分数维方法 GaAs薄膜 极化子 低维异质结构     

不同重力环境下辐射加热材料表面着火特性分析

研究外界辐射加热下，不同重力环境中热薄燃料的着火特性．探讨了重力、环境氧浓度、环境压力及外界辐射强度对着火的影响．结果表明，随着重力的变化，存在不同的着火机制．在微重力和在高的环境氧浓度中，材料的着火延迟时间变短．压力减小，着火延迟时间增大．随着辐射强度的增大，着火延迟时间变小．     

ZnSe/SiO2复合薄膜光学常数与荧光光谱的研究

采用溶胶-凝胶工艺与原位生长技术，制备了ZnSe/SiO₂复合薄膜.X射线衍射分 析表明薄膜中ZnSe晶体呈立方闪锌矿结构.X射线荧光分析结果显示薄膜中Zn与Se摩尔比为1 ∶1.01—1∶1.19.利用场发射扫描电子显微镜观察了复合薄膜的表面形貌，结果表明复合薄 膜表面既存在尺寸约为400nm的ZnSe晶粒，也存在尺寸小于100nm的ZnSe晶粒.利用椭偏仪测 量了薄膜椭偏角Ψ，Δ与波长λ的关系，采用Maxwell-Garnett有效介质理论对薄膜的光学 常数、厚度、气孔率、ZnS 关键词： 2复合薄膜')" href="#">ZnSe/SiO₂复合薄膜 光学性质 椭偏光度法 荧光光谱