钨镍共掺杂V2O5薄膜的光电特性研究

利用溶胶–凝胶旋涂法和后退火工艺在FTO导电玻璃上制备了钨镍共掺杂V₂O₅薄膜,研究了薄膜在不同温度和不同偏压下的光电特性和相变特性。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM） 和X射线光电子能谱仪（XPS） 测试了钨镍共掺杂V₂O₅薄膜的晶体结构、表面形貌和组分,分析了不同钨镍共掺杂浓度对V₂O₅薄膜相变光电特性的影响。结果表明,当钨和镍的掺杂质量分数分别为3 %和1.5 %时,钨镍共掺杂的V₂O₅薄膜的相变温度为218.5 ℃,在可见光范围内有较高的透过率,在近红外1310 nm波长处的光学透过率达48.83%,与未掺杂V₂O₅薄膜的光学透过率相比提高了10.29%,薄膜电阻降低了30.53%,热致回线宽度收窄为15 ℃,说明钨镍共掺杂的V₂O₅薄膜具有良好的可逆相变光电特性,有望在新型光电器件领域得到较好的应用。     

氧化铌在玻璃结构中的特性及其应用

本文将铌硅酸盐玻璃结构与性能的理论研究成果应用于光学玻璃研制过程。在LaF₂、LaF₃和LaF₄等稀土光学玻璃中,引入了Nb₂O₅,极大地改善了工艺稳定性,显着地提高了光学玻璃的内在质量和成品率,本工作为稀土光学玻璃的研制与生产提供了又一新的途径。     

基于Ge2Sb2Se4Te1的可重构光开关的仿真

光开关是集成光路上一个重要的元器件。提出了一种用在L和C波段基于硫系相变材料（Ge₂Sb₂Se₄Te₁）的片上2×2定向耦合器式的可重构光开关,可通过改变相态切换开关。利用仿真软件Lumerical中的Mode Solutions和FDTD Solutions模块设计器件,得到在1500~1625 nm内耦合长度为24.9 μm的Ge₂Sb₂Se₄Te₁非晶态下插入损耗（IL）>-0.36 dB,串口对比度（CT）<-24 dB;Ge₂Sb₂Se₄Te₁晶态下IL>-0.44 dB,CT<-30.46 dB。利用仿真软件COMSOL模拟532 nm波长激光加热Ge₂Sb₂Se₄Te₁,结果显示：一个25 ns、峰值功率45 mW的高斯短脉冲可以使材料由晶态转化为非晶态;施加多个峰值功率20 mW、周期1 μs且占空比0.03%的高斯脉冲阵列可重回晶态。仿真结果表明,设计的光开关在通信波段通过激光加热可以快速实现切换光路的作用。     

铌硼镧锌系统玻璃的研究

根据X射线、差热分析与扫描电镜等测定数据,获得了以下实验结果:1)Nb₂O₅的引入显著扩展了硼镧锌系统玻璃生成范围。其方向主要出现在B₂O₃含量降低或La₂O₃含量增加的区域Nb₂O₅形成了玻璃网络。     

光热敏微晶玻璃的制备及其特性研究

研究了SiO₂-R₂O-Al₂O₃-ZnO-B₂O₃(R=Li、Na、K)系统的玻璃组成及光敏、热敏组分对敏化、成核及受控结晶的影响。在1320～1420℃熔化制备了原始透明玻璃。用=2537Å光源进行光刻,经400～560℃及2～5h热处理工艺,获得了性能良好的光热敏微晶玻璃。测定了玻璃中微晶相的密度变化,证明了体积效应。由x射线粉末衍射分析鉴定其微晶相为Li₂O·SiO₂,晶粒尺寸为23.8nm.     

H2O/CO2污染对煤油燃料超声速燃烧影响数值研究

在纯净空气与H₂O/ CO₂污染空气来流对比试验结果基础上,采用数值计算方法和化学动力学方法,研究了H₂O和CO₂污染组分对煤油燃料超声速燃烧的影响,获得了试验手段难以得到的燃烧室流场参数和性能数据。完成了相应的煤油燃料超声速燃烧室二维数值计算,其中匹配了进口总温、总压、马赫数、氧气摩尔分数和工作当量油气比。将数值计算结果与相应试验测量值进行了对比分析,并结合燃烧室流场数据、性能参数分析了H₂O和CO₂污染的动力学影响、以及对燃烧室性能的影响。研究表明:(1)数值计算结果与实验测量值总体上吻合,两种手段均体现了纯净空气来流时不同煤油当量油气比的燃烧室性能,并反映了一致的“污染效应”影响趋势;(2) H₂O污染、H₂O+ CO₂污染的存在降低了煤油燃料超声速燃烧室性能,体现在燃烧诱导压升、燃烧效率、流向冲量增量的下降,而且随着污染组分含量的增加,燃烧室性能下降越加显著。      

单价银离子在 CaO-P2O5 系统玻璃中的发光特性

在弱还原气氛下制备了单价银离子(Ag⁺)掺杂的CaO-P₂O₅系统玻璃,测试了其在室温下的吸收光谱、激发光谱和发射光谱。Ag⁺-CaO-P₂O₅玻璃的吸收光谱表明两个吸收峰。高能峰位于220nm波长,由4d¹⁰→4d⁹5P¹跃迁引起,低能峰中心位于240nm波长,归因于4d¹⁰→4d⁹5s¹跃迁,该吸收与其发射特性有关。紫外波段的宽带吸收产生了可见波段强烈的荧光发射,发光峰位于440nm波长,半宽度为130nm.研究了掺质浓度与发光特性的关系,随着掺质浓度的增加(0.05～0.25mol%),发光峰向较长波段移动。在Ag₂O含量为0.5mol%时,出现了浓度猝灭现象。为了比较起见,同时还研制了Cu⁺-CaO-P₂O₅及Cu⁺-Ag⁺-CaO-P₂O₅玻璃。     

快速轴流型与密封型CO2激光器超脉冲特性研究

快速轴流型CO₂激光器和密封型CO₂激光器超脉冲运转时,能够获得前沿迅速上升、脉宽窄、峰值功率高的激光脉冲输出,在激光加工和激光医疗等领域有重要应用价值。本文从理论和实验两个方面对快速轴流型与密封型CO₂激光器超脉冲特性进行了研究,设计并研制了适合CO₂激光器超脉冲运转的控制电源,在国内首次实现了快速轴流型与密封型CO₂激光器的超脉冲运转。     

阿达马光谱术中的数据处理方法—快速阿达马变换

本文系统的讨论了应用于阿达马光谱术中的数据处理方法——快速阿达马变换。给出了:1.阿达马矩阵的构造方法。2.阿达马光谱术中矢量方程的建立。3.置换π₁,π₂的构造。4.判别任意2ⁿ（n≥o）阶阿达马矩阵中任意元素H_μj的判别式的给出:H_μj=(-1)^{μ_n-1j_n-1+μ_n-2j_n-2+…+μ₁j₁+μ₀j₀}。5.快速阿达马变换算式的建立。6.快速阿达马算法的验证。     

HfO2薄膜的离子束刻蚀特性研究

实验研究了HfO₂薄膜特性以及掩模材料AZ1350以Ar为工作气体下的离子束的刻蚀特性.给出了离子能量、离子束流密度和离子束入射角等因素与刻蚀速率的关系曲线,用最小二乘法拟合了上述因素与刻蚀斜率的函数关系方程;分析了光刻胶和基片在刻蚀过程中随刻蚀深度的变化对图形转移精度的影响,用AFM的Tapping模式测量了刻蚀前后HfO₂薄膜表面质量的变化.结果表明刻蚀速率与离子能量的平方根,及速流密度成正比,并随离子束入射角变化而变化;与刻蚀前相比,刻蚀工艺降低了因HfO₂薄膜刻蚀深度的增加引起图形转移精度下降,因此提高刻蚀选择比是获得高分辨率图形的前提.研究结果已应用到了在HfO₂/SiO₂多层膜衍射光栅的制作中.     

掺杂BaF2晶体的性能研究

为提高 BaF₂晶体的性能,生长了掺杂 LaF₃、NaF、CeF₃及纯的 BaF₂晶体,测试了其紫外透过谱、X 射线激发发射谱、紫外光激发谱、抗辐照性能及能谱,发现只有掺杂1.0%LaF₃的 BaF₂晶体能大幅度降低慢成份而对快成份影响不大且在10⁵～10⁶rad辐照剂量之下和纯 BaF₂一样在快成份光输出上有抗辐照能力,首次发现掺杂 LaF₃的BaF₂晶体紫外光激发谱中,385nm 处新激发峰。     

Effects of Glass-to-Rubber Transition on the Friction Properties of ZrO2 Reinforced Polybenzoxazine Nanocomposites

The present work is a generic study to examine the effects of the glass-to-rubber transition of resin matrix on the friction and wear characteristics of zirconium oxide (ZrO₂) reinforced polybenzoxazine nanocomposites, in relation to the content of ZrO₂. The thermal and tribological properties of the nanocomposites were measured by dynamic mechanical thermal analysis (DMA) and friction test, respectively. DMA results revealed that the storage modulus and T _g values of the nanocomposites increased with increasing ZrO₂ content to 4 wt%, due to the exceptional mechanical strength of ZrO₂ particles and the interfacial adhesion between ZrO₂ and matrix to restrict the segmental motion of polymer. The friction coefficient (COF) values as a function of applied load (50?C750?N) for the nanocomposites under testing temperatures (50, 100, 200, 250, and 300?°C) were measured. Comparable to the pure resin, the nanocomposites possessed relatively higher COF values with the increase of applied pressure under varying temperatures, which resulted from the reinforcement of ZrO₂. It is noted that the nanocomposites containing 4 wt% ZrO₂ occupied relatively higher modulus and glass transition temperature, resulting in better capability to stabilize the friction coefficient and wear rate under the applied conditions. In addition, the friction mechanism of the nanocomposites were proposed based on the experimental and reference results.     

Sliding Wear of Electrically Conductive ZrO<Subscript>2</Subscript>−WC Composites Against WC–Co Cemented Carbide

ZrO₂-based composites with WC addition can be successfully machined by electrical discharge machining (EDM) in demineralised water. ZrO₂ composites with 40 vol.% WC were produced from nanocrystalline and micrometre sized WC starting powders in order to compare their tribological behaviour. Friction and wear data are obtained on wire-EDM’ed ZrO₂–WC composite flats sliding against a WC–Co cemented carbide pin using a small-scale pin-on-plate testing rig. Correlations between wear volume, wear rate and friction coefficient on the one hand and material properties and test conditions on the other hand were elucidated. The experimental results revealed that the grain size of the electro-conductive WC-phase exhibits a strong influence on the friction and wear behaviour of the ZrO₂-based composite.     

Effect of ZrO2 Nanoparticles Additive on the Tribological Behavior of Multialkylated Cyclopentanes

Monodisperse ZrO₂ nanoparticles with a particle size of about 6–7 nm and low volatile multialkylated cyclopentanes (MACs) lubricant were prepared and characterized. The effect of ZrO₂ nanoparticles as additive on the friction and wear behavior of MACs base oil was investigated. The friction and wear performance of 2 wt% ZrO₂ nanoparticles + MACs was evaluated using an Optimal SRV oscillating friction and wear tester, with a steel ball sliding against the same steel counterpart disc. Results indicate that the wear resistance and load-carrying capacity of MACs base oil were markedly raised and its friction coefficient changed little when 2 wt% ZrO₂ nanoparticles were added to it.     

β-BaB2O4晶体在连续波可调谐环形染料激光器腔内倍频

本文以角调谐β-BaB₂O₄晶体用于若单明6G连续波环形染料激光器内腔倍频, 在290—305nm波段范围产生了可调谐紫外辐射.在296nm处, 最大二次谐波功率输出为0.6mW.线宽2MHz.     

Effect of Mo and Ag on the friction and wear behavior of ZrO2 (Y2O3)–Ag–CaF2–Mo composites from 20 °C to 1000 °C

In this paper, a series of ZrO₂ matrix high-temperature self-lubricating composites were prepared by hot-press technique. The effect of Mo and Ag on the friction and wear behavior of the ZrO₂(Y₂O₃)–Ag–CaF₂–Mo composites in a wide temperature range was investigated. The XRD results showed that CaMoO₄ formed on the worn surface above 400 °C. The excellent lubrication performance of CaMoO₄ endowed the low coefficient of friction of the ZrO₂(Y₂O₃)–Ag–CaF₂–Mo composites at high temperatures. The ZrO₂(Y₂O₃)–10Ag–10CaF₂–10Mo composites showed favorable wear resistance at all the tested temperatures which was attributed to the combined action of hardness and phase transformation.     

Experimental study of the speed-dependence tribotechnical characteristics of some plasma-sprayed oxide coatings at elevated temperatures

The effect of the sliding speed on friction and wear characteristics of plasma-sprayed ceramic coatings (Al₂O₃-13% TiO₂, ZrO₂-8% Y₂O₃, Al₂O₃-modified) was studied. Plasma-sprayed coatings are not hard and have high layered structure. Abrasion of coatings in the friction pair with steel and bronze counter-bodies occurs through brittle detachment conglomerated regions with low cohesive resistance. The modified coating (Al₂O₃) has the highest wear resistance and the lower coefficient of friction compared to the coatings (Al₂O₃-13% TiO₂, ZrO₂-8% Y₂O₃) in the studied velocity range (0.1–10 mm/s). Laser melting can be used as an efficient way of increasing the tribotechnical properties of plasma-sprayed oxide coatings.     

掺杂BaF2晶体的性能研究

生长了十几种掺杂的Ba₂F晶体.研究了共闪烁性能和抗辐照性能, 发现有些杂质对BaF₂闪烁体的光输出有很大影响, 另一些杂质影响不大, 还有的杂质不但影响不大, 而且还大大地提高了BaF₂晶体严重辐照损伤后的恢复能力.对上述结果作了解释.首次提出[F₂]心模型来解释BaF₂晶体220nm快成份发光的机制及其现象.     

LD泵浦的全固体绿激光器研究

主要论述了用激光二级管(LD)泵浦、内腔倍频的绿激光器的原理和结构。在激光阈值、斜效率的讨论中指出:当LD的泵浦光束在激光晶体中的尺寸越小,光功率密度越高,激光阈值就越低,转换效率就越高;在放大基波的结构中,激光腔镜对基波的反射度越高,基波的放大倍数就越大,转换效率就越高;重点讨论了内腔倍频激光器中的“绿光问题”,指出造成“绿光问题”是由于模式正交分量之间的和频效应与空间烧孔形成的横向饱和;用Poincare图分析了激光器中出现的混沌行为;对如何克服“绿光问题”,得到稳定激光输出提出了几种方案。针对LD的光形状是一个椭圆光锥,选择了用多组透镜准直、棱镜对扩束的泵浦光传输系统方案;对腔体、激光膜层作了概述,具体提出了用平凹腔结构,并把激光膜层直接做在晶体上,可以减少腔内损耗;对YAG-KTP,YVO₄-KTP组合的绿激光器作了研究。在内腔倍频YAG激光器中观察到的实验现象很好地附合理论结果。在YVO₄-KTP的绿激光器中,比内腔倍频YAG激光器较容易得到YAG-KTP组合绿激光器,最大连续输出功率为14.4mW,阈值15.0mW,光-光斜效率为4.1%.YVO₂-KTP绿激光器:最大连续输出120mW,阈值100mW,光-光斜效率为6.3%.     

Studying tribological characteristics of alumina- and zirconia-based ceramics

Tribotests of ceramic specimens of various compositions (Al₂O₃-1% TiO₂, ZrO₂-5.3% Y₂O₃, Al₂O₃-15% (ZrO₂ + 5.3% Y₂O₃)) were carried out under dry friction conditions. It has been shown that all of the specimens have a high wear resistance, while the Al₂O₃-15% (ZrO₂ + 5.3% Y₂O₃) specimens have the lowest wear rate and the highest microhardness. This is due to the fine-grained structure of these specimens and their higher density compared to that of the other ceramic compositions.