Preparation of Pt/Ce–Zr–Y mixed oxide/anodized aluminium oxide catalysts for hydrogen passive autocatalytic recombination

The use of a Pt-based catalyst was evaluated for autocatalytic hydrogen recombination. The Pt was supported on a mixture of Ce-, Zr- and Y-oxides (CZY) to yield nanosized Pt particles. The Pt/CZY/AAO catalyst was then prepared by the spray-deposition of the Pt/CZY intermediate onto an anodized aluminium oxide (AAO) layer on a metallic aluminum core. The Pt/CZY/AAO catalyst (3 × 1 cm) was evaluated for hydrogen combustion (1–8 vol% hydrogen in the air) in a recombiner section testing station. The thermal distribution throughout the catalyst surface was investigated using an infrared camera. The maximum temperature gradient (ΔT) for the examined hydrogen concentrations did not exceed 36 °C. The Pt/CZY/AAO catalyst was also evaluated for prolonged hydrogen combustion duration to assess its durability. An average combustion temperature of 239.0 ± 10.0 °C was maintained for 53 days of catalytic hydrogen combustion, suggesting that there was limited, or no, catalyst deactivation. Finally, a Pt/CZY/AAO catalytic plate (14.0 × 4.5 cm) was prepared to investigate the thermal distribution. An average surface temperature of 212.5 °C and a maximum ΔT of 5.4 °C was obtained throughout the catalyst surface at a 3 vol% hydrogen concentration.     

Dual effect synergistically triggered Ce:(Y,Tb)3(Al,Mn)5O12 transparent ceramics enabling a high color-rendering index and excellent thermal stability for white LEDs

Ce:Y₃Al₅O₁₂ transparent ceramics (TCs) with appropriate emission light proportion and high thermal stability are significant to construct white light emitting diode devices with excellent chromaticity parameters. In this work, strategies of controlling crystal-field splitting around Ce³⁺ ion and doping orange-red emitting ion, were adopted to fabricate Ce:(Y,Tb)₃(Al,Mn)₅O₁₂ TCs via vacuum sintering technique. Notably, 85.4 % of the room-temperature luminescence intensity of the TC was retained at 150 °C, and the color rendering index was as high as 79.8. Furthermore, a 12 nm red shift and a 16.2 % increase of full width at half maximum were achieved owing to the synergistic effects of Tb³⁺ and Mn²⁺ ions. By combining TCs with a 460 nm blue chip, a warm white light with a low correlated color temperature of 4155 K was acquired. Meanwhile, the action mechanism of Tb³⁺ ion and the energy transfer between Ce³⁺ and Mn²⁺ ions were verified in prepared TCs.     

Unraveling the effect of alumina-supported Y- doped ceria composition and method of preparation on the WGS activity of gold catalysts

The demands for high-purity hydrogen required in fuel-cell applications impose new goals and challenges for design of well performing water-gas shift (WGS) catalysts. Gold-based catalysts have exhibited high activity in the WGS reaction at low temperature. Preparation of appropriate and economically viable supports with complex composition by various synthesis procedures is an attractive approach to WGS performance improvement. The effect of two different preparation methods (wet impregnation or mechanical mixing) and ceria content (10, 20 or 30 wt%) on textural, structural, surface and reductive properties and WGS activity of gold catalysts was studied. Additionally, the role of Y₂O₃ as a promoter of ceria was examined. Long-term stability test was carried out at 260 °C over the most active catalyst. The composition of the best performing sample (composed of about 70 wt% alumina), prepared by mechanical mixing, was considered promising in case of practical applications because of its cost efficiency. The combination of gold nanoparticles and alumina supported Y-doped ceria proved an advantageous approach for developing new catalytic formulations with high effectiveness in clean hydrogen production.     

计量用脉冲Nd：YAG倍频激光器及其电源

介绍了脉冲Nd:YAG倍频激光器双波长（1064／532nm）3种输出的激光光路。1064nm输出的动静比可达0.40；KTP晶体外腔倍频效率可达0.50。介绍了稳定可靠的调Q电路、逻辑控制电路和开关电源的主电路及其参数计算。     

Nd:YAG激光治疗慢性肥厚性鼻炎对鼻腔黏液纤毛系统的影响研究

本文对Nd：YAG激光的三种不同方法治疗慢性肥厚性鼻炎治疗前、治疗后的鼻粘膜的临床表现及黏液毛系统的光镜、电镜进行了对照研究，对Nd:YAG激光治疗慢性鼻炎提供了理论依据。     

应用激光活化饵料藻种的研究

应用Nd:YAG激光(波长1.06μm,功率5w,照射时间0.5-3 min)和Ar+激光(波长488nm,功率70mw,照射时间5-15min)对长期保存的不同保存形式的塔胞藻(Pyramidomonassp.)进行辐照处理。研究了不同剂量激光辐照对藻体生长和叶绿素含量的影响。实验结果表明:照射剂量为60s的Nd:YAG激光及剂量为15min的Ar+激光对液体保存形式的藻种有较明显的促长效果,接种后这两种激光处理组的比生长速率分别较对照提高达53.33%和28.89%,叶绿素含量分别增加73.33%和65.69%。两种激光对液体保存藻种的活化效果均好于固体保存种。     

激光辐照对不同饵料微藻生长的影响

利用Nd:YAG激光(波长1.06μm,功率5W,照射时间0.5-3min)和Ar 激光(波长:488nm,功率70mw,照射时间5-20min)分别照射角毛藻和叉鞭金藻,辐照后进行细胞增殖和生长速率的测定。实验结果表明:照射剂量为1min的Nd:YAG激光及剂量为5min的Ar 激光对叉鞭金藻有较明显的促长效果,这两种激光处理组的细胞增殖量在辐照后的两天内较对照组分别高42.9%和48.1%,但这种促长效果随时间的推移逐渐消失。不同剂量的两种激光辐照角毛藻后,在延滞期均出现生长抑制现象,但进入指数生长期或传代培养后,剂量为1min的Nd:YAG激光及剂量为10min的Ar 激光对角毛藻有明显的促长效果,其中在指数生长期1min剂量的Nd:YAG激光处理可促长27.0%,传代培养后10min的Ar 激光处理组生长速率提高达51.2%。本文对不同激光及不同激光参数条件下,两种饵料藻的耐受性及生长特性的差异也进行分析探讨。本实验结果不仅证实了已有研究的推论,还展示出激光技术在饵料藻种选育中的应用前景。     

静压下ZnS：Te中Te等电子陷阱的发光

研究了4块ZnS：Te薄膜样品(Te组分从0．5％到3．1％)的光致发光谱在常压下的温度特性．对于Te组分较小的2块样品观察到2个发光峰，分别来自Te1和Te2等电子陷阱；而对Te组分较大的2块样品则只观察到1个来自Te2等电子陷阱的发光．我们还研究了这些发光峰在低温1．5K下的流体静压压力行为．观察到与Te1有关的发光峰压力系数比ZnS带边的要大很多，而与Te2有关的发光峰压力系数则比带边小．根据Koster-Slater模型，价带态密度半宽随压力的增加是Te1中心有较大压力系数的主要原因，而Te1和Te2中心的不同压力行为则是由于压力对两者缺陷势增强的不同效果引起的．     

Ce,Eu双掺BSO晶体光折变效应研究

在ＢＳＯ晶体中同时掺入Ｃｅ和Ｅｕ离子，生长了Ｃｅ：Ｅｕ：ＢＳＯ晶体，对晶体的二波耦合和四波混频性能了测试。结果表明，Ｃｅ和Ｅｕ离子对晶体的光折变效应起到了增强的作用。     

YAG光学功能陶瓷材料

对日本研制的ＹＡＧ光学功能陶瓷的制备工、性能作了较详细的介绍。与过去的ＹＡＧ单晶陶瓷作了对比，并对其发展及应用前景进行了分析。