SOA功率均衡技术的误码率性能分析

对光交叉连接 (OXC)节点中采用半导体光放大器 (SOA)功率均衡技术的方案性能进行了理论分析。首先模拟计算了链路中引入SOA后的功率代价 ;然后逐一讨论了发射机消光比 ,信号码率 ,SOA的噪声系数对系统性能的影响 ;最后计算了OXC节点级联链路的误码率性能。从而为OXC节点和网络设计提供了理论分析和指导依据。     

信息安全在邮政金融网中的实现

随着邮政金融网络化进程的推进,邮政金融系统的安全风险也越来越高,因此如何实现网络信息安全成为保证邮政金融系统正常运行至关重要的因素.文中介绍了实现网络信息安全的有关技术及实现方法,如数据加密、数字签名、防火墙等.通过应用这些安全防范技术,提出相应的网络信息安全方案,使邮政金融信息能够安全地在网络中进行通信.合理的网络安全方案和完善的管理体制是邮政金融网络系统安全运行的必要条件.     

A Catalytic and Shape‐Memory Polymer Reactor

An originally designed catalytic and shape‐memory polymer reactor is reported. This reactor is made of a unique shape‐switchable polymer composed of a thermosensitive control layer and an inert substrate layer. With the inert substrate layer made of poly(acrylamide), the thermosensitive control layer consists of nickel nanoparticles and a smart polymer composite of poly(1‐vinylimidazole) (PVIm) and poly(acrylic acid) (PAAc) that exhibit switchable domains. The self‐healing and dissociation between PVIm and PAAc induce convex/concave‐switchable shapes in the resulting reactor, which cause tunable access to the encapsulated metal nanoparticles. In this way, this reactor demonstrates tunable catalytic ability. Unlike reported smart polymer reactors exhibiting tunable catalysis usually due to the thermal phase transition of poly(N‐isopropylacrylamide) (PNIPAm), this novel reactor adopts the shape‐switchable strategy for tunable catalysis. This novel design suggests a new protocol for the development of smart catalytic reactors, which opens new opportunities for controlled chemical processes.     

基于FPGA的HDB3编译码

主要分析NRZ(单极性不归零码)码与HDB3码(三阶高密度双极性码)之间的转换原理,并介绍了用FPGA(现场可编程门阵列)完成HDB3编译码器的设计思路。     

基于节点持续传输准则的认知传感器网络信道分配策略

在异构分级式认知传感器网络中,为提高数据分组的传输成功率,提出将节点划分为具备持续传输条件和不具备持续传输条件两类,两类节点分别以牺牲较多能耗和分配较优信道的方式提高数据分组的传输成功率,并由此得到一种集中式信道分配策略.为了降低节点在信息传输过程中每比特平均能耗,对数据分组自适应调节机制进行了优化,确保不具备持续传输条件的节点得到最优的传输数据分组大小.仿真结果证明,提出的分配策略和优化机制能够有效提高能量的使用效率,改善网络性能.     

换热型节能技术在基站中的应用研究

换热型节能技术虽在基站中得到了大量应用,但由于应用场景至今还没有科学客观定量评估规定,使工程实施处于一种无章可循的尴尬局面,阻碍了换热型节能技术的进一步推广和应用。深入研究分析了基站内各类设备工作环境温湿度、空气清洁度和换热型节能设备能效比等技术指标,对比了不同标准中相关技术指标,指出了不同标准相关技术指标差别和部分标准存在的问题,并结合大气空气质量和环境温度等因素,提出了换热型节能技术应用场景和新风系统工程设计方法。     

Energy efficiency optimization for HCNs based on small base station transmission power allocation

In the research of green communication, considering the base station (BS) power allocation from the perspective of energy efficiency (EE) is meaningful for heterogeneous cellular networks (HCNs) optimization. The EE of two-tier HCNs was analyzed and a new method for the network EE optimization was proposed by adjusting the small BS transmitting power. First, the HCNs ware modeled by homogeneous Poisson point processes (PPPs), and the coverage probability of BSs in each tier was derived. Second, according to the definition of EE, and the closed-form of EE was given by deriving the total power consumption and total throughput of HCNs respectively. At last, the analytical performance of the EE of HCNs on the small BS transmission power was analyzed, and a small BS power optimization algorithm was proposed to maximize the EE. Simulation results show that, the transmission power of small BS has a significant impact on the EE of HCNs. Furthermore, by optimizing the transmission power of small BS, the EE of HCNs can be improved effectively.     

Non‐Volatile Polymer Electroluminescence Programmable with Ferroelectric Field‐Induced Charge Injection Gate

Electroluminescence (EL) of organic and polymeric fluorescent materials programmable in the luminance is extremely useful as a non‐volatile EL memory with the great potential in the variety of emerging information storage applications for imaging and motion sensors. In this work, a novel non‐volatile EL memory in which arbitrarily chosen EL states are programmed and erased repetitively with long EL retention is demonstrated. The memory is based on utilizing the built‐in electric field arising from the remnant polarization of a ferroelectric polymer which in turn controls the carrier injection of an EL device. A device with vertically stacked components of a transparent bottom electrode/a ferroelectric polymer/a hole injection layer/a light emitting layer/a top electrode successfully emits light upon alternating current (AC) operation. Interestingly, the device exhibits two distinctive non‐volatile EL intensities at constant reading AC voltage, depending upon the programmed direct current (DC) voltage on the ferroelectric layer. DC programmed and AC read EL memories are also realized with different EL colors of red, green and blue. Furthermore, more than four distinguishable EL states are precisely addressed upon the programmed voltage input each of which shows excellent EL retention and multiple cycle endurance of more than 10⁵ s and 10² cycles, respectively.     

公用电话的现状及未来发展方向

本文介绍了公用电话系统新的技术特点，并分析、总结了它的未来发展方向。