微通道板真空体电阻与Ⅱ代倒象微光管匹配关系的研究

国内研制的20/30Ⅱ代倒象微光管经常出现微通道板真空体电阻偏高或偏低的问题,直接影响Ⅱ代倒象微光管荧光屏的亮度和目标分辨力,严重影响微光管的质量。经过对20/30Ⅱ代倒象微光管的研制和理论分析,证明英国马拉德公司对用于××1383Ⅱ代倒象微光管的H36微通道板技术条件中真空体电阻技术指标的规定也存在一定的问题。本文从目前国内外工艺水平和有关文献资料的分析出发,进行专题研究。本文中所推导的计算公式和对文献资料提供的技术数据的推导分析,同样适用于其他型号微通道板的真空体电阻与相应Ⅱ代、Ⅲ代微光管匹配关系的计算与研究。     

Light scattering by groups of spherical particles

Light scattering by groups of spherical particles is considered. It is shown that the structure of the groups and their orientational distribution can be judged from the spectrum and polarization of the scattered light. Syktyvkar State University, 55, Oktyabr'skii Ave., Syktyvkar, 167001, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 228–231, March–April, 1997.     

自发参量下转换光场的实验研究进展综述

自发参量下转换(spontaneous parametric down-conversion,SPDC)光场是基于单色泵浦光子流和量子真空噪声对非线性晶体的综合作用而产生的,它固有的量子起源决定了在非经典光场研究中的重要地位和作用.对SPDC光场的相干特性和它在绝对测量光电探测器量子效率中的应用进行了深入而细致的研究和探讨.     

Synthesis and optoelectronic properties of silole‐containing polyfluorenes with binary structures

2,5‐Bis(2‐bromofluorene‐7‐yl)silole was prepared by a modified one‐pot synthesis with a reverse addition procedure, from which novel silole‐containing polyfluorenes with binary random and alternating structures (silole contents between 4.5 and 25% and high M_w up to 509 kDa were successfully synthesized. The well‐defined repeating unit of the alternating copolymer comprises a terfluorene and a silole ring. Optoelectronic properties including UV absorption, electrochemistry, photoluminescence (PL), and electroluminescence (EL) of the copolymers were examined. The different excitation energy transfers from fluorene to silole of the copolymers in solution and in the solid state were compared. The films of the copolymers showed silole‐dominant green emissions with high absolute PL quantum yields up to 83%. EL devices of the copolymers with a configuration of ITO/PEDOT/copolymer/Ba/Al displayed exclusive silole emissions peaked at around 543 nm and the highest EL efficiency was achieved with the alternating copolymer. Using the alternating copolymer and poly(9,9‐dioctylfluorene) as the blend‐type emissive layer, a maximum external quantum efficiency of 1.99% (four times to that of the neat film) was realized, which was a high efficiency so far reported for silole‐containing polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 756–767, 2007     

The effect of ITO films thickness on the properties of flexible organic light emitting diode

Indium tin oxide (ITO) thin films were deposited on cyclic olefin copolymer substrate at room temperature by an inverse target sputtering system. The crystal structure and the surface morphology of the deposited ITO films were examined by X-ray diffraction and atomic force microscopy, separately. The electrical properties of the conductive films were explored by four-point probing. Visible spectrometer was used to measure the optical properties of ITO-coated films. The performance of the flexible organic light emitting diode device with different thickness anode was investigated in this study.     

双轴晶体Nd^3＋：KGd（WO4）2的非偏振吸收光谱研究

报道了用三个方向相互垂直的非偏振吸收光谱测量计算Ｊｕｄｄ－Ｏｆｅｌｔ参数从而算出双轴晶体Ｎｄ３＋ＫＧｄ（ＷＯ４）２的荧光寿命、荧光分支比和发射截面的方法。得到的荧光寿命为１１９μｓ，平均发射截面为２．３×１０－１９ｃｍ２。     

透同光路指示光的CO_2激光器

报导封离型可透同光路指示光的ＣＯ２激光器的研制，并给出了其电流—工作特性曲线。对需可见光作同光路指示的ＣＯ２激光应用整机的开发，开辟了一条新的途径。     

Properties of polystyrene-poly(methylmethacrylate) random and diblock copolymers in dilute and semidilute solutions

Solution properties for random and diblock copolymers of polystyrene (PS) and poly(methyl methacrylate) (PMMA) have been measured by dynamic and total intensity light scattering in solvents of differing quality. The results are compared with the corresponding properties for PS and PMMA homopolymers of similar molecular weight, in order to determine if interactions between unlike monomers are significant. The hydrodynamic radius (R_h) and diffusion second virial coefficient (k_d) for the random copolymer are found to be larger than the corresponding values for the homopolymers in a solvent which is near-theta for the two homopolymers, whereas no such effect is observed for the block copolymer. This suggests that most intrachain interactions occur a relatively short distance along the chain backbone. In a mutual good solvent R_h and k_d of the random copolymer are comparable to the average of the values for the homopolymers, indicating that in a good solvent monomer/solvent interactions dominate over monomer/monomer interactions. For an isolated diblock copolymer in a mutual good solvent, there is no evidence that interactions between unlike monomers lead to additional expansion of the entire molecule, as measured by R_h, nor expansion of the individual blocks as probed by light scattering with one block optically masked. However, at low but finite concentration there is evidence (the coefficients of the binary interaction terms in the viscosity and the mutual diffusion coefficient, and the second and third virial coefficients) that a weak ordering effect may exist in block copolymer solutions, far from the conditions where microphase separation occurs. Finally, measurements of ternary polymer-polymer-solvent solutions show no dependence on monomer composition or monomer distribution for the tracer diffusion of probe PS-PMMA copolymers in a PMMA/toluene matrix. This indicate that the frictional interaction is largely unaffected by interactions between unlike monomers. However, there is evidence that the thermodynamic interaction is more unfavorable between a random copolymer and the homopolymer matrix than between a diblock and the matrix. © 1994 John Wiley & Sons, Inc.     

光纤码分多址技术在城域接入网中的应用

分析了光纤码分多址技术O -CDMA在城域接入网中的应用。回顾了O -CDMA技术的发展历史 ,详细地介绍了O -CDMA技术的特点 ,其具有的公平性、灵活性、网络控制管理、对服务区处理能力以及高的安全性使O -CDMA技术成为较好的城域接入网技术。阐述了目前在应用中O -CDMA存在的一些技术方面的问题     

Implementation and experimental study on fast object modeling based on multiple structured stripes

In this paper, a practical structured light-based system for fast object modeling and reconstruction is reported. The system consists of an off-the-shelf digital projector, a video camera and a turntable. The system calibration is implemented accurately and automatically by taking a single image of an illuminated calibration template. The multiple color light stripes emitted by the projector adopt only three colors and the color can be modified easily according to the surface texture of the object. This makes the system widely applicable in many situations, and the assumption about color neutrality, which is a limitation to other similar systems, can be largely relaxed. The registration and merging algorithm is greatly simplified by employing a turntable. The validity and high accuracy of the method are demonstrated by extensive real experiments.