基于FDTD的三角形银纳米颗粒阵列等离子共振吸收特性的模拟

利用时域有限差分法,数值模拟了银纳米三角阵列的等离子共振吸收特性,仿真计算了银纳米颗粒尺寸大小对阵列等离子体共振的影响.数值计算结果表明,三角形银纳米颗粒阵列的等离子共振吸收峰随颗粒尺寸的增大而红移,可通过改变颗粒大小调节共振吸收波长数值以用于不同的应用研究.基于FDTD理论模拟的计算结果与实验规律基本相符,并较好地阐释了银纳米三角有序阵列表面等离子共振吸收峰的频移与其纳米粒子长径比之间的一些依赖关系,此结论将有利于纳米光传感器应用的进一步探索研究.     

Transmission resonance and color generation of metal- dielectric subwavelength gratings in visible regions

Metal-dielectric subwavelength gratings under s-polarized and p-polarized visible radiation are studied for discovering their intriguing behaviors of spectral resonance and color property.The dependence of their resonance and color on grating parameters as well as angle of incidence and position of plane of incidence is also analyzed.For s-polarized light,the behavior of spectral resonance with single peak and higher peak efficiency is found.While transmission spectra for p-polarized light are not able to achieve a behavior like that of s-polarization,creating a perceived color is feasible.Moreover,a security grating with distinctive color shifts has been designed and its resonant properties as well as related color variation have also been provided.     

基于光纤连接的腔系统实现两比特离散量子傅立叶变换

提出了在外加经典场驱动的情况下,利用光纤连接的2个腔系统执行两比特离散量子傅立叶变换的方案.该方案通过发送2个原子交替通过一系列经典场和腔场来实现,而且该两比特方案可推广至N比特离散量子傅立叶变换.     

Thermodynamic analysis of simplified dual-pressure ammonia-water absorption power cycle

A simplified dual-pressure ammonia-water absorption power cycle (DPAPC-a) using low grade energy resources is presented and analyzed. This cycle uses turbine exhaust heat to distill the basic solution for desorption. The structure of the cycle is simple which comprises evaporator, turbine, regenerator (desorber), absorber, pump and throttle valves for both diluted solution and vapor. And it is of high efficiency, because the working medium has large temperature difference in evaporation and small temperature difference in absorptive condensation, which can match the sensible exothermal heat resource and the cooling water simultaneously. Orthogonal calculation was made to investigate the influence of the working concentration, the basic concentration and the circulation multiple on the cycle performance, with 85–110 °C heat resource and 20–32°C cooling water. An optimum scheme was given in the condition of 110 °C sensitive heat resource and 20 °C cooling water, with the working concentration of 0.6, basic concentration of 0.385, and circulation multiple of 5. The thermal efficiency and the power recovery efficiency are 8.06 % and 6.66%, respectively. The power recovery efficiency of the DPAPC-a is 28.8% higher than that of the steam Rankine cycle (SRC) and 12.7% higher than that of ORC (R134a) under the optimized situation.     

二进小波与扩散滤波结合的光学相干层析图像降噪

斑点抑制各向异性扩散(SRAD)是一种重要的图像降噪方法。将二进小波与SRAD结合,提出一种光学相干层析图像的二进小波扩散滤波降噪方法。该方法利用二进小波分解得到的不同尺度间小波系数的相关性区分边缘和噪声,修改SRAD中扩散系数得到新的扩散系数计算公式。实验表明,新方法具有更好的降噪能力,降噪后得到的图像的信噪比和对比度噪声比率等量化衡量指标都优于经典SRAD方法。     

大相对孔径红外变焦距光学系统设计

设计了工作在8~12μm波段的非致冷红外连续变焦光学系统。该系统由4组元5片透镜组成,其中前固定组、变倍组和补偿组均只有1片透镜,后固定组为两片。焦距50~200mm,相对孔径较大,为1∶1。设计过程中编写了适用于二组元变焦系统的ZEMAX宏程序,该程序可给出凸轮曲线的数据和形状,同时使像面位置不受限于高斯光学关系,能够满足某些焦距位置离焦的要求。系统在空间频率为20lp/mm处,各个视场的MTF值均在0.4以上。     

光测设备特种载车结构设计

光测设备特种载车是光测设备实现机动布站的专用运输工具和承载平台。在光测设备载车结构设计时,除采用普通车辆的设计方法外,还提出了针对四轮独立悬挂式特种载车的设计方法,重点对载车有别于其他特种车的厢盖、厢体、底盘及辅助设施的结构设计方法进行了阐述。并对关键零部件进行了强度校核计算。通过对光测设备载车的平顺性实验,光测设备各典型部位的振动加速度均方根值小于0.5G。为同类型光测设备载车的设计提供了可供参考的依据。     

光纤之父——华裔诺贝尔奖获得者高锟的科学思想与方法研究

被誉为“光纤之父”的香港中文大学校长高锟教授是第八位华裔诺贝尔自然科学奖获得者,由于他在光纤材料和传输研究方面取得的突破性成就,开创了人类光纤信息通讯的新时代。本文从高锟成长的历程探讨了东西方教育对他日后科学研究和技术创新的影响,分析了他在光纤通信研究方面取得杰出贡献对人类开创信息时代的意义和价值。最后,研究了高锟的科学思想和方法的三大特点：重视直觉,学会基于问题的思考,激发超越逻辑的灵感;关注创造,善于独树一帜的思维,追求另辟溪径的探索;强调方法,既要脚踏实地地研究,也要高瞻远瞩地看路。     

山东昌乐锆石的谱学特征及变生程度

利用激光拉曼光谱、红外吸收光谱并结合宝石学特征对山东昌乐某蓝宝石砂矿中的锆石谱学特征和变生程度进行了研究.拉曼图谱显示,锆石的变生系数H/W值(1007 cm-1)大都大于600(在625～5412,仅1个为441),主要为全晶质锆石和弱变生锆石,变生程度很小.红外光谱的结果表明,锆石的结晶程度高度一致,H/M值(610 cm-1):原样为20～23,氧化条件热处理(600℃)后为20～22,还原条件热处理(600℃)后为28～30,判断为晶质锆石;样品的物理性质与晶质锆石比较接近.因此,所测样品为变生程度很弱的高型锆石,还原条件下热处理后锆石的变生系数有明显增大,其结晶度有所改善.