1064nm激光和355nm激光同时辐照DKDP晶体的耦合预处理效应

为了研究DKDP晶体在惯性约束核聚变(ICF)装置应用中的多波长激光诱导损伤特性,建立了1064 nm激光和355 nm激光同时辐照DKDP晶体的损伤测试装置,分析了不同激光能量密度组合下的损伤针点形貌、密度、尺寸和损伤概率。结果表明,当355 nm激光以R-on-1方式辐照样品,并加入不同能量密度的1064 nm激光时,随着1064 nm激光能量密度的升高,测试样品的抗激光损伤性能得到改善,损伤针点形貌逐渐与1064 nm激光单独作用时的损伤形貌类似,损伤针点密度减小,损伤针点尺寸增大,整体上表现出耦合预处理效应。     

Study for infrared spectroscopic ellipsometric properties of diamond films

Spectroscopic ellipsometric measurements in infrared region (2.5 - 12.5 μm) are carried out to characterize the structure and quality of diamond films grown by microwave plasma chemical vapor deposition (MPCVD) and hot filament chemical vapor deposition (HFCVD), respectively. It is found that the establishment of appropriate models has the strongest influence on the fit of ellipsometric spectra. The best fit is achieved for MPCVD film with a 77.5-nm middle layer of SiO2, and for HFCVD film with an 879-nm rough surface layer included by Bruggeman effective medium approtimation (EMA). Finally the refractive index and the extinction coefficient are calculated for both films, the results show that the film grown by MPCVD is optically much better than that grown by HFCVD at infrared wavelengths.     

悬空氧化铟纳米线晶体管制备与光电性能表征

一维(1D)半导体纳米线在纳米电子学和纳米光子学中表现出色.然而,纳米线晶体管的电特性对纳米线与衬底之间的相互作用非常敏感,而优化器件结构可以改善纳米线晶体管的电学和光电检测性能.本文报道了通过一步式光刻.     

烧结多孔表面强化冷凝传热的实验研究

实验研究了不同粒径金属粉末烧结制备的多孔涂层表面对垂直管外水蒸气冷凝传热的强化作用。发现:粒径为50μm的细粉覆盖一层及两层的多孔管的传热效果反而不如光管,使冷凝传热效果恶化;而粉末粒径为250μm的烧结表面的强化传热特性比光管提高10％～15％,而且也明显优于粒径为50μm的表面。同时,两种不同粒径表面,两层粉末错落堆积烧结表面的传热效果也优于单层粉末烧结表面。基于孔隙微观结构变化对冷凝液流动与导热的影响分析讨论了多孔烧结表面强化膜状冷凝传热的机理。     

Study for infrared spectroscopic ellipsometric properties of diamond films

Spectroscopic ellipsometric measurements in infrared region (2.5 - 12.5 μm) are carried out to characterize the structure and quality of diamond films grown by microwave plasma chemical vapor deposition (MPCVD) and hot filament chemical vapor deposition (HFCVD), respectively. It is found that the establishment of appropriate models has the strongest influence on the fit of ellipsometric spectra. The best fit is achieved for MPCVD film with a 77.5-nm middle layer of SiO2, and for HFCVD film with an 879-nm rough surface layer included by Bruggeman effective medium approtimation (EMA). Finally the refractive index and the extinction coefficient are calculated for both films, the results show that the film grown by MPCVD is optically much better than that grown by HFCVD at infrared wavelengths.     

消除CCD不良背景的工艺研究

对电荷耦合器件(CCD)交流成像中存在的背景发白、亮条、亮点、拖影和固定图像噪声等不良背景进行了分析,并提出了调整栅介质生长方法、本征吸杂、低温退火等消除不良背景的具体工艺方法,获得了高质量的CCD器件.测试结果表明,其交流成像中的不良背景得到了有效控制.     

金刚石薄膜的红外椭圆偏振光谱研究

采用红外椭圆偏振光谱对微波等离子体化学气相沉积法（MPCVD）和热丝化学气相沉积法（H-FCVD）制备的金刚石薄膜在红外波长范围（2.5—12.5μm）的光学参数进行了测量.建立了不同的光学模型，且在模型中采用Bruggeman有效介质近似方法综合考虑了薄膜表面和界面的椭偏效应.结果表明，MPCVD金刚石膜的椭偏数据在模型引入了厚度为77.5nm的硅表面氧化层、HFCVD金刚石膜引入879nm粗糙层之后能得到很好的拟合.最后对两种模型下金刚石薄膜的折射率和消光系数进行了计算，表明MPCVD金刚石薄膜的红外 关键词： 金刚石薄膜 红外椭圆偏振光谱 光学参数 有效介质近似     

基于双曲面弯晶技术的便携式X射线荧光光谱仪快速测定土壤中(类)金属元素的含量

为解决常规便携式X射线荧光光谱仪现场检测土壤(类)金属元素时存在的检测元素种类少、部分元素检出限高等缺点,选择GB 15618-2018、GB 36600-2018、农业农村部发布的《第三次全国土壤普查工作方案》包含的重(类)金属元素、金属营养元素以及具有开采价值的(类)金属元素作目标元素,对题示方法的应用可行性(检出限、精密度、准确度)进行了全面考察。土壤样品经烘干、研磨、压实后,用配有双曲面弯晶的便携式X射线荧光重金属分析仪分析,采用快速基本参数法(Fast FP)定量。结果显示：Cd、Hg、As、Cu、Sb、Tl、Mo、Sn、Se、Cs等主要目标元素的检出限为0.2～3 mg·kg^-1,基本低于环境背景值或上述标准要求的限值(Hg和Se除外)。按照试验方法分析3种水系沉积物成分分析标准物质和两种土壤成分分析标准物质,除测定值在测定下限以下的元素以及Tl、Mg元素外,标准物质中其余主要目标元素测定值的相对标准偏差(n=7)基本低于20%,相对误差的绝对值基本低于35%,Cu、Pb、Cr、Zn和Ni等基础项目元素测定值的相对标准偏差和相对误差符合或接近HJ/T ...     

化学变脸之神奇的超浸润——推荐一个化学科普实验

自然界中有一类神奇的超浸润,如荷叶上水珠和水黾轻功"水上漂"等,这是材料表面特异的微纳超级结构和活性物质所致。效法自然,合成了两种超浸润界面剂和一种开关型的Cu(OH)2@ZIF-8纳米网膜。从自然植物–日常应用–科技发展,由浅入深,全方位地科普了神奇而又不乏科学趣味的自然现象(化学变脸),以激发青少年对于自然、科学的兴趣。     

Study for infrared spectroscopic ellipsometric properties of diamond films

Spectroscopic ellipsometric measurements in infrared region (2.5 - 12.5 μm) are carried out to characterize the structure and quality of diamond films grown by microwave plasma chemical vapor deposition (MPCVD) and hot filament chemical vapor deposition (HFCVD), respectively. It is found that the establishnent of appropriate models has the strongest influence on the fit of ellipsometric spectra. The best fit is achieved for MPCVD film with a 77.5-nm middle layer of SiO2, and for HFCVD film with an 879-nm rough surface layer included by Bruggeman effective medium approtimation (EMA). Finally the refractive index and the extinction coefficient are calculated for both films, the results show that the film grown by MPCVD is optically much better than that grown by HFCVD at infrared wavelengths.