212 resultados para tin


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采用等离子电弧沉积法在9Cr18钢表面制备了厚约0.5 μm的TiN薄膜,通过显微硬度测试以及纳米压痕和纳米划痕试验,对比考察了9Cr18钢及其表面TiN薄膜的机械和摩擦性能。结果表明,9Cr18钢及其表面TiN沉积膜的纳米硬度分别为8GPa和38GPa,弹性模量分别为250GPa和580 GPa,9Cr18、TiN和有机薄膜的摩擦系数分别为0.40、0.12和、0.10;TiN沉积膜可显著提高基体钢的承载和耐磨能力。

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采用等离子电弧沉积的方法分别在GT35和40CrNiMo钢上沉积厚约为0.5mm 的氮化钛(TiN)膜。为了筛选基材,采用纳米压痕和划痕技术评价膜基界面结合和固体润滑效果。纳米压痕结果,采用等离子电弧沉积的方法,分别在GT35和40CrNiMo钢上沉积厚约为0.5$\mu $m 的氮化钛(TiN)膜。为了筛选基材,采用纳米压痕和划痕技术,评价膜基界面结合和固体润滑效果。纳米压痕结果,GT35,40CrNiMo和TiN的纳米硬度/弹性模量的典型值分别约为11.5 Gpa/330 Gpa,6.0 Gpa/210 Gpa,30 Gpa/450 Gpa。纳米划痕结果,GT35有较理想的膜基结合能力;GT35,40CrNiMo,TiN及其有机膜的摩擦系数分别约为0.25,0.45,0.15,0.10。同40CrNiMo相比,GT35是较为理想的基体材料。纳米压痕和划痕技术能提供丰富的近表面的弹塑性变形、断裂和摩擦等的信息,是评价亚微米薄膜力学性能的有效手段。

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用扫描电镜对比分析了电弧离子镀增加直线磁场过滤对沉积TiN和TiAlN薄膜中颗粒的密度和尺寸的影响,,结果表明,TIN薄膜中颗粒的最大直径,从14μm减小到3μm,颗粒密度从lO~9/cm~2。降低到10~5/cm~2.TilN薄膜由于靶材中含有低熔点金属Al,因而发射出更大的颗粒,有的颗粒集团达到20μm,磁场过滤后颗粒尺寸减小,颗粒密度降低到10~6/cm~2。分析了脉冲叠加直流偏压对TiCrZrN复合薄膜相组成的影响。颗粒可使电弧离子镀rriN/crN多层膜的结合力降低,并使针孔产生遗传。使用直线型磁场过滤及脉冲叠加直流偏压不仅使颗粒密度和尺寸显著降低和减小,而且多层化对小颗粒产生了包覆作用。

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采用等离子电弧沉积的方法,分别在GT35和40CrNiMo钢上沉积厚约为0.5μm的氮化钛(TiN)膜。为了筛选基材,采用纳米压痕和划痕技术,评价膜基界面结合和固体润滑效果。纳米压痕结果,GT35,40CrNiMo和TiN的纳米硬度/弹性模量的典型值分别约为11.5 GPa/330GPa, 6.0 GPa/210GPa, 30GPa/450GPa。纳米划痕结果,GT35有较理想的膜基结合能力;GT35,40CrNiMo,TiN及其有机膜的磨擦系数分别约为0.25,0.45,0.15, 0.10。同40CrNiMo相比,GT35是较为理想的基体材料。纳米压痕和划痕技术能提供丰富的近表面的弹塑性变形、断裂和磨擦等的信息,是评价亚微米薄膜力学性能的有效手段。

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采用真空磁过滤电弧离子镀方法,在GT35基体上沉积类金刚石膜。通过对清洗工艺及弧电流、工件所加负偏压、沉积温度等参数的研究,制定出了合理的工艺路线,并对这种膜层进行了X-射线光电子谱(XPS)分析,利用干涉仪、纳米硬度计对膜层的粗糙度、纳米硬度作了进一步检测。结果表明,采用此种方法制备的类金刚石膜层,SP^3含量约为40.1%;组织致密,无大的颗粒;镀膜后的粗糙度可以达到0.015μm;纳米硬度约为55GPa。并将膜层与TiN膜层组成摩擦副,进行了耐磨性试验。结果表明膜层的耐磨性较好。

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建立了一套利用高功率YAG激光器辐照固体锡靶产生高转换效率极紫外光(extreme ultraviolet)源的实验装置.利用建立的实验装置开展了极紫外光源的强度和转换效率与抽运激光强度关系的实验研究,发现极紫外光源的转换效率随抽运激光强度的变化具有饱和效应.实验发现:当抽运激光能量达到250mJ时,极紫外光源的转换效率最高,波长为13.5nm处0.27nm带宽范围内的极紫外光源的能量转换效率为1.6%,此时对应的激光强度为1.8×1011W/cm2.

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根据STANNEX氧化锡电极(以下简称锡电极)的热导率曲线,以平壁导热为模型,建立了锡电极中心轴向温度分布的简化模型。根据锡电极使用的实际情况建立实验炉,测试了锡电极在稳态下的边界温度以及锡电极中心在稳态下的实际温度分布。根据实验所测得的边界条件对锡电极的温度分布作了深入细致的推导。用有限差分法求出了锡电极的轴向温度分布,计算结果跟实际测试温度能较好地吻合。对电极导电的牵引材料的选择有很好的指导意义,同时也为玻璃电熔的散热与功率配置以及电极使用过程中的冷却提供了较好的参考。根据实际温度情况采取相应的冷却措

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Thermal stability, Raman spectra and blue upconversion luminescence properties of Tm-3divided by /Yb-3divided by -codoped halide modified tellurite glasses have been Studied. The results showed that the mixed halide modified tellurite glass (TFCB) has the best thermal stability, the lowest phonon energies and the strongest upconversion emissions. The effect of halide on upconversion intensity is observed and discussed and possible upconversion mechanisms are evaluated. The intense blue upconversion luminescence of Tin (3+) in TFCB Glass may be a potentially useful material for developing upconversion optical devices.. (C) 2004 Elsevier Ltd. All rights reserved.

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Electrochemically active Polypyrrole (PPy) nano-fiber array device was fabricated via electrochemical deposition method using aluminum anodic oxide (AAO) membrane as template. After alkaline treatment electrochemically active PPy nano-fiber lost electrochemical activity, and became electrochemically inactive PPy. The electronic properties of PPy nano-fiber array devices were measured by means of a simple method. It was found that for an indium-tin oxide/electrochemically inactive PPy nano-fiber device, the conductivity of nano-fiber increased with the increase of voltage applied on the two terminals of nano-fiber. The electrochemical inactive PPy nano-fiber might be used as a nano-fiber switching diode. Both Au/electrochemically active PPy and Au/electrochemically inactive PPy nano-fiber devices demonstrate rectifying behavior, and might have been used for further application as nano-rectifiers. (c) 2005 Elsevier B.V. All tights reserved.

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Tin oxide doped beta-Ga2O3 single crystals are recognized as transparent conductive oxides (TCOs) materials. They have a larger band gap (4.8 eV) than any other TCOs, thus can be transparent in UV region. This property shows that they have the potential to make the optoelectronic device used in even shorter wavelength than usual TCOs. beta-Ga2O3 single crystals doped with different Sn4+ concentrations were grown by the floating zone technique. Their optical properties and electrical conductivities were systematically studied. It has been found that their conductivities and optical properties were influenced by the Sn4+ concentrations and annealing. (c) 2006 Elsevier Ltd. All rights reserved.

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采用中频感应提拉法生长了高质量的Tm:Y2SiO5(Tm:YSO)晶体,测定了晶体的晶格常数和分凝系数.运用劳厄照相法确定了单斜晶系Tm:YSO晶体的三个偏振轴〈010〉,D1和D2,在室温下测量了三个偏振轴方向的吸收光谱、荧光光谱和荧光寿命,计算了晶体吸收峰的吸收线宽和吸收截面.研究发现,相对于其他两个偏振轴方向,D1方向在790 nm处出现较强的吸收峰,同时在2μm附近出现了一定强度的发射峰,D1方向的吸收截面较大,荧光寿命较长.Tm:YSO晶体适用于AlGaAs二极管抽运固体激光器,在2μm波段固体激光器的应用上将有很大的发展潜力.

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ZnO/ITO/ZnO sandwich structure films were fabricated. The effects of buffer layer on the structure and optical properties of ZnO films were investigated by x-ray diffraction (XRD), photoluminescence, optical transmittance, and absorption measurements. XRD spectra indicate that a buffer layer has the effects of lowering the grain orientation of ZnO films and increasing the residual stresses in the films. The near-band-edge emissions of ZnO films deposited on both single indium tin oxide (ITO) buffer and ITO/ZnO double buffers are significantly enhanced compared with that deposited on a bare substrate due to the quantum confinement effect. (C) 2006 American Institute of Physics.

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用直流磁控溅射法制备透明导电锡掺杂氧化铟(ITO)薄膜,靶材为ITO陶瓷靶,组分为m(In2O3):m(SnO2)=9∶1。运用分光光度计、四探针测试仪研究了基底温度对薄膜透过率、电阻率的影响,并用X射线衍射(XRD)仪对薄膜进行结构分析。计算了晶面间距和晶粒尺寸,分析了薄膜的力学性质。实验结果表明,在实验设备条件下,直流磁控溅射ITO陶瓷靶制备ITO薄膜时,适当的基底温度(200℃)能在保证薄膜85%以上高可见光透过率下,获得最低的电阻率,即基底温度有个最佳值。薄膜的结晶度随着基底温度的提高而提高。

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The phylogenetic relationships within the family Penaeidae are examined based on mitochondrial 16S rRNA gene sequence analysis of 30 species from 20 genera. The analysis generally supports the three- tribe scheme proposed by Burkenroad ( 1983) but it is not consistent with the five- group classification of Kubo ( 1949). Three clades are resolved: ( Penaeus sensu stricto + Fenneropenaeus + Litopenaeus + Farfantepenaeus + Marsupenaeus + Melicertus + Funchalia + Heteropenaeus), ( Metapenaeus + Parapenaeopsis + Xiphopenaeus + Rimapenaeus + Megokris + Trachysalambria) and ( Metapenaeopsis + Penaeopsis + Parapenaeus), corresponding to the Penaeini, Trachypenaeini and Parapenaeini respectively, while the affinities of Atypopenaeus and Trachypenaeopsis are obscure. The molecular data support that Miyadiella represents the juvenile stage of Atypopenaeus. Within the Trachypenaeini, Trachypenaeus sensu lato is clearly paraphyletic, while the monophyly of Penaeus sensu lato in the Penaeini is questionable.