格兰-泰勒棱镜和格兰-付科棱镜透射比的比较研究

为了验证空气隙的厚度是否对偏光棱镜的透射比产生影响,对格兰-泰勒棱镜和格兰-付科棱镜的透射比进行了详细的理论分析,并利用UV-3101分光光度计分别对两只格兰-泰勒棱镜和两只格兰-付科棱镜的透射比进行了实验测试,发现格兰-泰勒棱镜的透射比(85%左右)明显高于格兰-付科棱镜(50%左右)。理论分析表明,对于严格的准直光束,两种棱镜的透射比均随波长的变化而振荡,且这种振荡对格兰-付科棱镜强于格兰-泰勒棱镜;但在分光光度计上的测试并未出现振荡,这说明对于非严格准直的光束,空气隙的厚度并不影响棱镜的透射比。     

用二棱镜进行三自由度稳象

反射棱镜稳象,从本质上说可看为棱镜的自动调整的问题,它和棱镜调整在理论上有很多相似之处。因此我们对棱镜所起的稳象作用的分析,实际上就是对反射棱镜在运动状态下的物象空间的共轭关系的分析。用反射棱镜在运动状态下的共轭关系,结合以棱镜调整特性所进行的棱镜分类,可对几类棱镜的稳象作用和它们组合的稳象作用进行一些分析。象道威棱镜、别汉棱镜等一类棱镜称为象旋转器,它们都具有消除象倾斜的作用;而当上述一类棱镜的某一反射面为一屋脊面所取代,就把它们称为圆束偏器,它们可用来稳定光轴。而对于三自由度稳象就是要求反射棱镜既是象旋转器,又是圆束偏器。从反射棱镜的动态成象特性来看,一块反射棱镜不可能起到上述的两类棱镜的作用。但当二象旋转器棱镜的主截面相互     

空气隙偏光镜空气层厚度的优化设计

棱镜偏光镜的空气隙对其透射比同样具有影响,对空气隙的厚度进行优化设计对提高棱镜的透射比很具实际意义.以格兰泰勒棱镜为例,利用菲涅耳公式和多光束干涉理论,给出空气隙棱镜e光透射比的计算公式,分析了e光透射比随其空气隙厚度的变化规律,提出了为提高透射比棱镜空气隙厚度的最佳取值,从而实现棱镜的优化设计.     

Glan－Taylor偏光棱镜的设计

本文介绍的Glan-Taylor棱镜是一种重要的Glan型冰洲石偏光棱镜,广泛用于各种光学系统中。本文从半视场角与棱镜切割角的关系入手,分析了影响Glan-Taylor棱镜结构的若干参量,并介绍了一种棱镜设计方法,可以对用于任一波段起偏的这种棱镜实现结构的优化设计。     

利用全反射原理精确测量棱镜折射率

依据全反射原理和自准直测角法,实现了对棱镜折射率的精确测量。通过使用高准直半导体激光器将激光入射到棱镜内部与空气分界面上,逐步旋转棱镜或改变棱镜的入射角,得到待测棱镜的反射光强随入射角变化曲线。在曲线左侧收尾处出现一个台阶,其反射光强随入射角增大迅速衰减。全反射临界点,对应的入射角为全反射角。用两次自准直测角法精确测量棱镜底角。通过该方法,分别对两块不同棱镜的折射率进行了测量,测量棱镜折射率精度为±1.24×10-4。     

Glan－Taylor偏光棱镜的设计

本文介绍的Ｇｌａｎ－Ｔａｙｌｏｒ棱镜是一种重要的Ｇｌａｎ型冰洲石偏光棱镜，广泛用于各种光学系统中。本文从半视场角与棱镜切割角的关系入手，分析了影响Ｇｌａｎ－Ｔａｙｌｏｒ棱镜结构的若干参量，并介绍了一种棱镜设计方法，可以对用于任一波段起偏的这种棱镜实现结构的优化设计。     

直角棱镜腔偏振耦合输出特性研究

激光器采用直角棱镜腔具有较好的稳定性,在军用激光器中应用广泛,由于直角棱镜内发生全反射产生相移,耦合输出透过率与耦合波片的相移量、光轴方位角,以及直角棱镜材料和棱线方向有关,直角棱镜与波片的不同组合能够达到的最高耦合透过率不同;对直角棱镜偏振耦合特性进行了理论分析,并采用MATLAB软件计算不同相移波片的方位角与偏振透过率的关系,并对光波耦合过程中偏振状态变化进行了模拟,对不同材料直角棱镜的耦合特性进行了对比,并根据理论分析进行实验验证,这些研究对直角棱镜谐振腔的设计、调试以及直角棱镜材料的选择具有实际意义。     

微角分束偏光棱镜分束角的特性研究

为了了解微角分束偏光棱镜的分束特性,根据冰洲石晶体的光学性质以及光在棱镜入射与出射介面和棱镜中的传播方向,在光正入射的条件下,分析了棱镜的分束角随工作波长的变化关系; 在工作波长一定的条件下,分析了入射角对棱镜分束角大小的影响及规律; 设计了实验,对制作的棱镜样品进行了实验测试。结果表明,微角分束偏光棱镜的分束角随工作波长而变,且波长越短,分束角越大; 在棱镜的主截面内,入射角由-20°~20°变化时,分束角呈非线性由小变大。这一结果对于微角分束偏光棱镜的设计和使用具有实际价值。     

Wollaston棱镜晶体光轴的垂直偏差对分束特性影响分析

为了了解晶体光轴精度对Wollaston棱镜性能的影响,给出了光晶体轴存在纵向垂直偏差时Wollaston棱镜分束角的精确表达式,与常规Wollaston棱镜分束角进行分析表明：o光的分束角变小,d光的分束角不受影响：当Wollaston棱镜两部分的晶体光轴存在横向偏差时,棱镜的分束角及消光比均不受影响,但棱镜的透射比...     

窄线宽准分子激光腔内棱镜扩束器的优化设计

棱镜扩束器(PBE)广泛用在准分子激光腔内光谱压窄系统中,可以有效降低光束发散角和系统内能量密度。为了实现窄线宽激光输出并降低腔内损耗,需要对棱镜扩束器的棱镜个数、单棱镜扩束倍数和棱镜顶角进行优化设计。根据棱镜扩束倍数的理论,数值分析了入射角、顶角和出射角对棱镜扩束倍数的影响,并在实验上很好地验证了扩束倍数与入射角的关系。此外,推导了激光器线宽压窄系统实现一定激光线宽输出所需的总棱镜扩束倍数。优化设计了扩束倍数M为13.3的氟化钙消色散棱镜扩束器,在此基础上,实现了0.915pm的窄线宽ArF激光输出,实验结果与理论设计吻合。     

高校固定资产管理中云计算技术的应用探讨

随着时代的发展,国家对人才的需求量不断增加,并且对人才培养的要求越来越高。高校作为人才输出的重要基地,人们对高等教育的重视程度不断加深,尤其是近年来高校在发展的过程中其规模也在不断的扩展,导致固定资产管理中的一些问题逐渐凸显出来。本文就固定资产管理中存在的问题进行分析,进一步探讨云计算技术在高校固定资产管理中的应用。     

细支气管肺泡癌患者EGFR基因突变的研究

目的探讨表皮生长因子受体（EGFR）基因酪氨酸激酶域体细胞在细支气管肺泡癌（BAC）患者中突变的相关因素。方法分析和检测本院37例细支气管肺泡癌石蜡包埋标本EGFR基因突变状况,采用PCR技术进行EGFR基因18、19、20和21外显子突变分析。结果37例BAC患者中有18例（48．6％）酪氨酸激酶域存在体细胞突变,其中3例（8．1％）为18外显子替代突变,5例（13．5％）为19外显子突变,7例（18．9％）为20外显子替代突变,8例（21．6％）为21外显子替代突变。结论EGFR基因与BAC密切相关。     

UMTS及EPC网络QoS机制的研究

随着社会的发展,用户对业务质量的需求也日益提高,为此3GPP组织加强了对QoS的研究,在UMTS阶段引入了端到端QoS机制,并在LTE阶段对QoS机制进行了扩展和增强,目前QoS的研究是3GPP研究的一个热点。本文对3GPP移动通信网QoS演进进行了介绍,分析了UMTS和EPC网络的QoS实现机制,并对两种QoS实现机制进行了分析。     

Magnetic and Acoustically Active Lipospheres for Magnetically Targeted Nucleic Acid Delivery

With the aim of obtaining a carrier for combined magnetic‐field‐ and ultrasound‐targeted nucleic acid delivery, acoustically active lipospheres are prepared that comprise magnetic nanoparticles and plasmid DNA or synthetic siRNA. The lipospheres, with average diameters of 5 μm and smaller, are obtained upon shaking a mixture of soybean oil, a cationic lipid, magnetic nanoparticles, a nucleic acid, and aqueous buffer in a perfluoropropane atmosphere in a sealed vial. These lipospheres create contrast in ultrasound imaging and display greatly increased magnetophoretic mobility and in consequence greatly improved magnetic retention in a flow model when compared with free magnetic nanoparticles. In cell culture, the lipospheres are sedimented within minutes to the surface of cells using a gradient magnetic field. This sedimentation results in the association of about 50% of the applied plasmid DNA with the cells and in functional DNA and siRNA delivery in vitro. Under these conditions, ultrasound does not have an enhancing effect on nucleic acid delivery. When magnetic, acoustically active lipospheres carrying 125iodine‐labeled plasmid DNA are injected into the tail veins of mice, the application of a gradient magnetic field to the chests of the mice results in a two‐ to threefold enrichment of both lung lobes with the plasmid. A similar enrichment is obtained when ultrasound alone (1 MHz, 10 min) is applied. The combined application of magnetic field and ultrasound has no synergistic effect in terms of liposphere capture in the lungs. Histological analysis reveals intact lipospheres in lung capillaries. A synergistic effect of magnetic field and ultrasound is observed in site‐specific plasmid deposition in a dorsal skinfold chamber model in mice after injection into the carotis. These conditions also result in functional plasmid delivery to the vasculature after intrajugular injection.     

Improved LUT Technique for HPA Nonlinear Pre-Distortion in OFDM Systems

In this paper, we focus on the Look-up Table (LUT) technique for the compensation of HPA nonlinear distortion. An improved LUT method is proposed with better performance compared with conventional LUT technique in terms of convergence speeds, BER and total degradation (TD). It can get over 8 dB gain in out-of-band spectrum re-growth suppression and about 0.3 dB BER performance gain than conventional LUT technique with the same iteration times. Also, we propose an actual application of HPA with pre-distorter in OFDM transmitter. Ai Bo was born in Shannxi Province in China on February 7, 1974. He received a BSc. Degree from Engineering Institute of Armed Police Force in 1997, a Master and Dr. degree from Xidian University in 2002 and 2004 in China respectively, and now working as a post dr. in Dept. of E&E, state of key lab. on microwave and digital communications in Tsinghua University in China. He has once participated in the key research project on HDTV in TEEG (Team of Engineering Expert Group) of China. He is an editorial committee member of journal of “Computer Simulations”, “Information and Electronic Engineering”, an IEEE member and a senior member of Electronics Institute of China (CIE). He has published over 60 scientific papers in his research area till now. His current interests are the research and applications of OFDM techniques with emphasis on synchronization and HPA linearization techniques. Yang Zhi-Xing graduated from Tsinghua University, P.R. China in 1970. He is now a Professor and Deputy Director of State Key Lab. on Microwave and Digital Communication at the Department of Electronic Engineering and the Director of the DTV R&D Center in Tsinghua University. As a DTV technical expert for the Chinese government, Professor Yang has also been a member of the DTV standardization Committee of China and a leader of the DTV Standardization Harmonizing Group in Ministry of Information Industry of China. His major research interests include broadband information transmission technologies and DTV broadcasting systems. Pan Chang-Yong received the B.S. and M.S. degrees from the Department of Electronic Engineering in Tsinghua University, P.R. China, in 1996 and 1999, respectively. He is now an associate professor in the Department of Electronic Engineering and a member of the DTV R&D Center in Tsinghua University. His research interests are in the areas of broadband wireless transmission systems and satellite communications. Zhang Tao-Tao was born in Shandong Province in China in 1982, he received BSc. degree from Tsinghua University in 2004 and now pursing his Master degree in Dept. of E&E, state of key lab. on microwave and digital communications in Tsinghua University in China. His research interests is the power amplifier linearization techniques. Wang Yong was born in Shannxi Province in China in 1976. He received a BSc., a Master and a Dr. Degree from Xidian University in China in 1997, 2002 and 2005, respectively, and now is an associate professor in Xidian University. He has once participated in the key research project on HDTV in TEEG (Team of Engineering Expert Group) in China and is an IEEE Member. His interests are broadband multimedia communications. Ge Jian-Hua was born in September, 1961 in JiangSu Province in China. He received the B.Sc., Master and Ph.D. degree from Xidian University in 1982, 1985 and 1989, respectively. He is now the professor in both Xidian University in Xi’an and Shanghai Jiaotong University in Shanghai. He is the senior member of Chinese Electronics Institute. He has won lots of scientific and technical prizes in China and published many papers. His interests are transmission communications and web security.     

0.55 µm 激光在复杂组分雾霾中的散射传输特性

基于典型雾霾粒子的消光、吸收、散射截面、不对称因子参量和粒径分布函数的分析, 运用蒙特卡罗方法研 究了不同组分、不同混合方式的雾霾介质中波长 0.55 µm 激光的传输散射特性, 比较了典型污染物颗粒介质对光的透 射率影响。研究表明, 同等浓度下, 硫酸铵介质对光的透射率最高, 碳溶胶介质的透射率最低, 且雾霾的透射率小于灰 霾透射率。此外, 对不同混合状态簇团粒子组成介质的透射率比较分析表明, 典型污染物粒子外混合状态和内混合状 态对光的衰减性几乎相同, 而雾霾介质中水组分的分布对光的透射率有明显的影响。     

Smart cities education: An insight into existing drawbacks

Smart cities aim to increase citizens’ quality of life by employing technology. Education is one of the areas of focus in smart cities and in this context, smart education is a term used to refer to education provided by smart cities. As research in this area has expanded recently as shown by the number of literature reviews in a smart city context, a review could help summarize existing directions focusing in this case on education in the smart cities context. As our understanding on negative consequences is limited, this research will address this knowledge gap by concentrating on challenges and difficulties when it comes to education in smart cities. The articles indexed in Scopus and Web of Science were review and a qualitative analysis of the articles fitting our research criteria was done. Three themes were identified: shortcomings on the existing educational initiatives to address the needs of smart cities, negative consequences of smart city education in other areas and problems that arise as a result of employing technology in education.     

Optimization of Half-Rate Codec Assignment in GERAN

Half-Rate (HR) channel coding can be used to deal with temporary traffic peaks in Global System for Mobile Communications (GSM)/Enhanced Data Rates for Global Evolution (EDGE) Radio Access Networks. Since operators have to pay for the use of HR codecs, the number of transceivers on which HR can be used is normally limited. An algorithm that optimizes the assignment of a limited number of HR codecs in a network is presented. The final solution obtained with the greedy algorithm proposed has proved to be optimal. Subsequent application of the algorithm in a real environment shows significant performance benefits in terms of network congestion reduction in comparison to the current approach used by network operators. Matías Toril received an M.S. degree in telecommunication engineering in 1995 from the University of Málaga, Spain. Since 1997, he is on the staff of the Communications Engineering Department, where he is currently working toward a Ph.D. degree. From 2000 to 2003, he simultaneously joined the Nokia Networks Competence Team in Málaga. His research interests include optimization of mobile radio access networks and radio resource management. Ricardo Ferrer obtained his M.S. in Telecommunication from the University of Malaga in 2000. He joined the Nokia Networks Competence Team in Málaga in 2000, where he worked in control and optimization algorithms for telecommunication cellular networks. In 2003 he joined TarTec where he leads the development of a network optimization solution. Salvador Pedraza received an M.S. degree in electrical engineering in 1995 and Ph.D. in control engineering in 2000 from the University of Málaga, Spain. He joined Nokia Networks in July 2000 for three years. In June 2003 he co-founded TarTec for providing solutions and services for cellular network performance optimisation, being responsible of research and technology unit. His research interests include control and optimization techniques for mobile networks and stochastic processes theory. Volker Wille Following under graduate studies in Germany and an internship at Bell Communications Research, USA, Volker Wille carried out postgraduate studies in UK leading to a PhD degree. In Nokia, he currently is responsible for development of features that enable self-regulation of cellular networks. Juan J. Escobar obtained his M.S. in telecommunication engineering from the University of Málaga. He joined the Nokia Networks Competence Team in Málaga in 2001, where he worked in control and optimization algorithms for telecommunication cellular networks. In 2003 he joined TarTec, where he leads the development of a common framework for network performance optimization.     

普遍意义下介观RLC并联电路的量子化及在真空态下的量子涨落

对具有普遍意义的介观RLC并联电路进行量子化并对各支路电流与电压的量子涨落进行研究, 同时分析耗散电阻对两个支路的量子涨落所产生的影响. 结果表明:各支路的量子涨落均与电路元件的参数有关并且随时间而衰减; 而耗散电阻对电感支路和电容支路量子涨落的衰减因子及其系数均产生影响, 对两个支路电流与电压的量子涨落的衰减因子产生的影响相同, 而对其系数产生的影响不同.当电感支路与电容支路的耗散电阻相同时, 两个支路的电压涨落与耗散电阻有关, 而电流涨落不受耗散电阻的影响.     

免疫介导豚鼠脊髓运动神经元损伤的超微结构及钙稳衡改变

应用常规透射电镜及草酸盐-焦亚锑酸盐技术原位固定细胞内钙,对豚鼠脊髓前角细胞内的钙分布进行超微定位,探讨钙稳衡改变在免疫介导运动神经元损伤中的作用.结果发现模型组豚鼠脊髓前角运动神经元可见粗面内质网扩张、线粒体肿胀、嵴排列紊乱等.神经元周围胶质细胞增生.在运动神经元扩张的粗面内质网池和线粒体内室可见数量不等颗粒状电子致密的钙沉积物.线粒体内室内钙沉积颗粒与线粒体肿胀的程度相关.星形胶质细胞内肿胀的线粒体内室及扩张的粗面内质网池内也可见电子致密钙沉积颗粒.因此认为,钙稳衡失调参与了免疫介导的运动神经元损伤过程.