Switched-mode AGC circuits with internally created reset module for burst-mode unbalanced data optical receiver

This paper presents an innovative switched-mode auto gain control (AGC) circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced (BMU) optical data transmission.Conventional AGC circuit is inappropriate for BMU data transmission because it is based on average level detection and requires considerable time to settle on a predefined gain.Therefore,we adopt a fast switched-mode AGC based on peak level detection.After the gain is adjusted,the peak level detectors need to re-detect the peak level of the input signal.Thus,we develop an internally created reset module.This AGC with reset module exhibits a fast operation and achieves an adjusted stable gain within one-bit,avoiding any bit loss up to 10Mb/s data rate.During power-up,the peak level detectors possibly hold an uncertain level resulting in the bit-errors.We propose a power-up reset circuit to solve this problem.Designed in a 0.5 μm CMOS technology,the circuit achieves an optical sensitivity of better than - 30dBm and a wide dynamic range of over 30dB with a power dissipation of only 30 mW from a 5V supply.     

手机信号采集与传输技术设计与实现

嵌入式平台上,3G手机的信号采集和传输由于数据速率过高,在实现上存在较大的难度,设计了一种由射频芯片、FPGA和CY7C68013构成的手机信号采集和传输方案。以TD-SCDMA信号为例,设计了系统的硬件架构和软件部分,包括FPGA中的软件及USB固件程序。最后提出验证方案,结果表明,该方案能使高达102.4 Mbit/s的TD-SCDMA数据流实现准确无误的采集和传输。     

点内库仑相互作用对三量子点系统输运性质的影响

本文利用非平衡格林函数运动方程方法,研究了与两个电极耦合在一起的三耦合量子点系统中,点内部的库仑关联或阻塞与点间的耦合强度对体系输运性质,即对系统微分电导和系统态密度的影响.通过理论计算发现,由于量子点上的局域态密度的不同从而导致系统微分电导或隧穿性质的不同,会开启新的Kondo输运通道,也会增强一些原有的输运通道.     

自动校对中现代藏文音节字研究

现代藏文自动校对中,对音节字（ ）的校对是其基础。在藏文文本中音节字是用音节点进行间隔的,由于藏文二维的书写特征和音节字形成过程中与其构件之间严格的搭配规则等诸多问题,使得对它的校对又区别于任何一种文字。文章介绍了音节字的构件、结构和搭配规则等问题,列举了藏文音节字中的错误类型,并针对其特殊性给出了一个特有的音节字校对的流程和方法。     

活性染料代碱剂SM应用性能探讨

采用代碱剂SM替代碳酸钠对3种活性染料进行固色,探讨了固色代碱剂的用量对固色率、染色牢度等方面的影响.结果表明,代碱剂的质量浓度为1.6~2.0 g/L时即可达到较好的固色效果,且色光变化不明显,皂洗和摩擦牢度较好,可有效代替传统的固色碱剂.     

Toward the development of Mg alloys with simultaneously improved strength and ductility by refining grain size via the deformation process

Magnesium(Mg) alloys, as the lightest metal engineering materials, have broad application prospects.However, the strength and ductility of traditional Mg alloys are still relativity low and difficult to improve simultaneously.Refining grain size via the deformation process based on the grain boundary strengthening and the transition of deformation mechanisms is one of the feasible strategies to prepare Mg alloys with high strength and high ductility.In this review, the effects of grain size on the strength and ductility of Mg alloys are summarized, and fine-grained Mg alloys with high strength and high ductility developed by various severe plastic deformation technologies and improved traditional deformation technologies are introduced.Although some achievements have been made, the effects of grain size on various Mg alloys are rarely discussed systematically and some key mechanisms are unclear or lack direct microscopic evidence.This review can be used as a reference for further development of high-performance fine-grained Mg alloys.     

华为交换机一机双网技术的探讨

文章叙述了铁通从网络优化、运维作业组织优化和节约运营成本等方面需要,提出在公网交换机上实现原有专网交换机的功能,淘汰专网交换机,实现一机双网。     

Exponential stability for cellular neural networks: an LMI approach

A new sufficient conditions for the global exponential stability of the equilibrium point for delayed cellular neural networks （DCNNs） is presented. It is shown that the use of a more general type of Lyapunov-Krasovskii function enables the derivation of new results for an exponential stability of the equilibrium point for DCNNs. The results establish a relation between the delay time and the parameters of the network. The results are also compared with one of the most recent results derived in the literature.     

四节介质塞加载圆波导平面相控阵理论分析和优化设计

本文用积分方程法严格分析了四节介质塞加载圆波导平面相控阵,给出了阵列反射系数表达式。在分析基础上进行了优化设计,找到了一个合适的目标函数和优化方法。理论和实验对比结果表明,在整个频带内,大扫描角大致趋近,其它扫描角比较符合。     

不同他人在场对4～6岁儿童有意记忆影响的研究

本研究通过设置不同他人在场的情境探讨了４～６岁儿童有意记忆情况，以现：不同的他人在场是影响４～６岁ＪＬ童有意记忆的重要因素；不同的他人在场对４～６岁儿童有意记忆影响各不相同；男女儿童在不同的他人在场的条件下，有意记忆成绩的性别差异不同显著．