制备工艺对多孔阳极氧化铝特性的影响

通过对草酸溶液中制备的多孔阳极氧化铝(PAA)的形貌、晶态结构和光致发光(PL)特性的表征和机理分析,研究了草酸电解液浓度、阳极氧化电压和退火等丁艺对PAA的形成及特性的影响.PAA的孔径在50～120 nm之间,且随着阳极氧化电压的升高而增大,而受电解液浓度的影响较小.X射线衍射结果表明:PAA为非晶态结构,退火之后结晶,并有多相共存.PL测试表明PAA在375～500 nm之间有一较宽的蓝色发光带,发光峰在425 nm左右,是由氧空位引起的,且其峰强可通过改变阳极氧化电压和草酸浓度等参数来调制.     

运动对小白鼠乳酸脱氢酶(LDH)同工酶的影响初探

经总酶活性测定和凝胶电泳图谱分析发现:剧烈运动后,小白鼠六种组织LDH总酶活性,骨骼肌有显著升高,(p<0.05),其余五种组织均变化不显著;心肌、骨骼肌、肾脏的M型LDH相对活性显著升高(P<0.05),而H型LDH相对活性显著下降(p<0.05);相应地,A亚基比例显著升高,B亚基比例显著下降,这种变化似能反应剧烈运动对小白鼠厌氧代谢的明显影响.     

Semiconductor optical amplifier used as regenerator for degraded differential phase-shift keying signals

Phase and amplitude regeneration are necessary for degraded differential phase-shift keying communication systems.This paper proposes a regenerator based on semiconductor optical amplifier for differential phase-shift keying signals.The key regeneration mechanism is theoretically analysed.The effectiveness of semiconductor optical amplifier based regenerator is demonstrated by comparing the bit error rate and eye diagrams before and after regeneration for 40-Gbit/s differential phase-shift keying 1080-km transmission systems.The results show that regeneration effects are very well.Bit error rate is less than 10 12 with the regenerator.     

基于神经网络的三维宽场显微图像复原研究

提出一种利用BP神经网络进行三维宽场显微图像复原的非线性映射方法,将三维图像转化为二维图像进行处理,利用神经网络的学习能力,通过训练,建立含有散焦信息的二维模糊图像与二维清晰图像之间的映射关系,然后对切片堆叠进行逐幅复原,从而实现显微图像的三维复原.得到的复原图像在视觉上和定量分析上都获得了很好的效果.由于采用小规模神经网络,训练时间短,计算量小,使实时复原成为可能.     

980 nm激发下Er3+/Yb3+共掺杂ZrO2-Al2O3粉末的上转换发光特性

通过固相反应法制备了Er3+/Yb3+共掺杂ZrO2-Al2O3粉末的样品,并对样品在980nm激光激发下的上转换发光特性进行了研究.从发射光谱可以发现,在可见光范围内有3个强的发光带,一个位于654nm附近的红光带和两个分别位于545nm、525nm附近的绿光带,分别对应于Er3+离子的以下辐射跃迁:4F9/2→4I15/2、4S3/2→4I15/2、2H11/2→4I15/2.其中又以Er3+离子的4F9/2→4I15/2跃迁产生的红色荧光辐射最强.对其上转换发光机制进行了分析,发现这三个发光过程都是双光子过程.对样品粉末进行了XRD检测,发现ZrO2主要以立方相为主,并且计算得到了这种立方结构的晶格常数.Al2O3固溶于ZrO2中,Al3+嵌入ZrO2后产生氧空位,导致ZrO2晶体的对称性降低,这种结构变化更有利于提高上转换效率,即上转换发光强度增强.     

SiO2脊形条波导热极化引起的电光效应

通过理论模拟对具有上覆盖层的SiO2脊形条波导结构进行了优化,在此基础上利用微电子工艺制作了SiO2脊形波导Mach-Zehnder 型电光调制器,并进行热极化引起的电光和非线性效应的研究.热极化过程大幅增强了样品的电光及非线性效应,二次电光系数由热极化前的1.56×10-22(m/V)2提高到热极化后的8.50×10-22(m/V)2,极化后得到了0.093pm/V的线性电光系数,对热极化的物理机理进行了理论分析.     

Mid-infrared supercontinuum generation to 4.5 microm in ZBLAN fluoride fibers by nanosecond diode pumping

A mid-infrared supercontinuum (SC) is generated in ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF...) fluoride fibers from amplified nanosecond laser diode pulses with a continuous spectrum from approximately 0.8 microm to beyond 4.5 microm. The SC has an average power of approximately 23 mW, a pump-to-SC power conversion efficiency exceeding 50%, and a spectral power density of approximately -20 dBm/nm over a large fraction of the spectrum. The SC generation is initiated by the breakup of nanosecond laser diode pulses into femtosecond pulses through modulation instability, and the spectrum is then broadened primarily through fiber nonlinearities in approximately 2-7 m lengths of ZBLAN fiber. The SC long-wavelength edge is consistent with the intrinsic ZBLAN material absorption.     

傅里叶变换红外光谱仪遥测污染云团的吸收光谱算法

遥感傅里叶变换红外光谱技术因其具有对污染源作无干扰监测、多组分的同时连续测定、区域性或大范围地区的测量等优点,因而已广泛的应用于遥感测量技术。利用傅里叶变换红外(FTIR)光谱仪远距离探测目标,根据探测的目标源是否充满光谱仪的视场,建立了三种辐射模型。在所建立模型的基础上,选用了D&P公司生产的便携式Model-101型傅里叶变换红外光谱仪,实时探测目标云团和背景,运用差谱法和发射光谱法对探测结果进行了光谱分析,进而得到了扣除背景影响后的目标云团吸收光谱。给出了相应的仿真实验结果示例。实验结果表明,由差谱法得到的结果准确度较好。     

Fabrication of polymer compound microlens by lens-on-lens microstructures

We proposed a novel method for fabricating polymer compound microlenses (PCMLs) using micro-inkjet technique and subsequent curing process. Two different types of PCMLs with sandwich microstructure (PDMS-Glycerol-PDMS), concave and convex PCMLs, have been designed and fabricated in experiments. Convex PCML has two real images and two foci. The concave PCML has one real and one virtual focal planes, which can generate one real image and one virtual image respectively. Moreover, the diameter of concave PCML can be controlled by adjusting the curing time and temperature. The proposed method is simple, efficient and suitable for realizing large-scale high numerical aperture PCMLs array, which has potential applications in diverse optical systems such as optical storage and three-dimensional imaging.     

嵌入式三色光变器

为了提升现有导模共振防伪光变器件的性能,设计了一种基于ZnS覆盖膜的一维单周期矩形结构三色光变器.当自然光入射角为45°时,可在0°,58°,90°方位角分别获得相应的蓝、绿、红三色反射峰,对研究结果进行了物理解释.分析并提出了该器件周期、槽深、膜厚以及入射角变化对反射峰的影响规律,对器件的设计、制作和测试有重要指导作用.三色光变器基于简单结构实现方位角调节的自然光三色光变效果,可运用传统激光全息产业的模压和蒸镀工艺进行制作,在光变图像防伪领域有重要应用.