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71.
一种高环境对比度(A-CR)和大开口率的显示器已经从理论上证明,并通过把一个正常显黑反射型显示器(NB-RLCD)和一个有机电致发光器件(OLED)堆垛的实验加以证明。这种前后双置(以下称为tandem型)的器件组合可以分别在明亮或昏暗的环境下切换NB-RLCD模式或OLED模式。RLCD的正常显黑特性也可以提升OLED模式工作时的A-CR性能。为了在RLCD模式下获得更好的图像品质,一个复杂并且具有传输功能的结构被用于消除镜面反射和提高可视角至CR﹥2:1超过55°的锥面可视角度。另外,这样的结构也可以提高OLED49.4%的表面量子效率。在我们的实验里,忽略环境亮度因素并使A-CR保持在100:1以上。  相似文献   
72.
The self-organizing mapping (SOM) and hierarchical clustering (HC) methods are integrated to detect brain functional activation; functional magnetic resonance imaging (fMRI) data are first processed by SOM to obtain a primary merged neural nodes image, and then by HC to obtain further brain activation patterns. The conventional Euclidean distance metric was replaced by the correlation distance metric in SOM to improve clustering and merging of neural nodes. To improve the use of spatial and temporal information in fMRI data, a new spatial distance (node coordinates in the 2-D lattice) and temporal correlation (correlation degree of each time course in the exemplar matrix) are introduced in HC to merge the primary SOM results. Two simulation studies and two in vivo fMRI data that both contained block-design and event-related experiments revealed that brain functional activation can be effectively detected and that different response patterns can be distinguished using these methods. Our results demonstrate that the improved SOM and HC methods are clearly superior to the statistical parametric mapping (SPM), independent component analysis (ICA), and conventional SOM methods in the block-design, especially in the event-related experiment, as revealed by their performance measured by receiver operating characteristic (ROC) analysis. Our results also suggest that the proposed new integrated approach could be useful in detecting block-design and event-related fMRI data.   相似文献   
73.
本文介绍了通信电源的基本状况及其主要特点;文中推荐的典型供电方案,正在各地推广应用。通信部门关于供电电源完善化方面的一系列考虑,对于改进其他在电力系统中运行的远动、自动和计算机等电子设备的电源,亦具有一定的参考价值。  相似文献   
74.
在便携电子产品市场,无线网络的出现让人们能够随时随地进行高效的无线通信,而这正是设计便携式电子产品时的首要考虑因素之一。无线调制解调器是一种与无线网络而非电话系统连接的调制解调器。当用户连接无线调制解调器时,实际上就直接连接了无线互联网服务提供商。全球移动通信系统(GlobalSystemforMobile,GSM)和通用分包无线服务(GeneralPacketRadioService,GPRS)无线调制解调器均由uSB的VBUS线供电,提供了一种实现通用式便携设备环境的好方法。不过,这种调制解调器设计也带来了功率管理问题,因为GSM和GPRS发送器需要高达2A的峰值电流,而这却超过了USB电源的最大电流容量。  相似文献   
75.
With the recent increase in routing App usage, it is urgent to analyze the impact of inevitable information delay in routing Apps on traffic. To analyze the negative impact of such delayed routing Apps on traffic, this paper investigates the impact of ideal and delayed routing Apps on traffic. Firstly, the effect of ideal routing Apps has been explored with theoretical analysis and derivation based on a macroscopic network model. Then, an extended network model is built to characterize the delayed routing. The impact of such delayed routing Apps is investigated by simulation experiments while considering routing usage proportion and amount of delay. The results demonstrate that ideal navigation does improve traffic efficiency, but in some cases, delayed navigation is even worse than no navigation.  相似文献   
76.
New energy power generation equipment has the characteristics of diurnal, perturbative, seasonal, and periodic power generation, which makes new power optical communication network(POCN) more dynamic and changeable. This is directly reflected in the dynamics of the link risk and service importance of the POCN. In this paper, aiming at the problem of the dynamic importance of service in POCN, and the resulting power optical communication network reliability decline problem, a new energy POCN dyna...  相似文献   
77.
1 Introduction High power laser diode arrays (LDA) have many advan- tages such as small volume, long working life, high slope efficiency and high optical density, so they have many applications in medical treatment, material pro- cessing, and for the pumping source of solid laser and etc. But unfortunately, the LDA can not be easy to use directly in these fields because of their poor beam quality and extremely asymmetric divergent beams (!x≈ 5°~10°and !y≈20°~35°, for example), so it …  相似文献   
78.
ZHAO Chong-guang    QU Zhou    LIU Yang    WANG Ji    WANG Li-jun 《光机电信息》2006,(6):28-35
1 Introduction Fiber lasers have been developed for more than forty years since Snitzer!s proposal and the demonstration of Nd- doped fiber in 1961 [1]. But fiber lasers have not been attracted considerable attention until the develop- ment of the low- loss fiber fabrication technology and the high power semiconductor laser technology recently. Actually,it is the application and development of fiber communication technology that has promoted the rapid development of fiber laser. Fiber laser, …  相似文献   
79.
I. Introduction Streaming media has been widely used over the Internet in recent years. However, the growing use in streaming media, which generally has large size, can have a significant impact on the user perceived latency and network congestion. A popular approach to reduce the response time and backbone bandwidth consumption is to deploy proxy caches at the edge of the Internet. Due to the large size and different popularity for different part of the streaming video, it is not practical …  相似文献   
80.
An all-fiber based Er^3+ :Yb^3+ co-doped double clad fiber laser operating at 1 550 nm is demonstrated. By using 9 m long Er^3+ : Yb^3+ co-doped fiber(EYDF) as the gain medium, and using a pair of fiber Bragg gratings as wavelength filters, the line-width of the output laser is as narrow as 0.2 nm and the output power is more than 6 mW. The fluorescent effect of the laser before its emission is also studied. And it is found that the Er^3+ : Yb^3+ co-doped double-clad fiber laser also exhibits a high gain for Yb^3+ transition near 1 080 nm.  相似文献   
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