No.7信令监测系统的发展与应用

简要介绍No.7信令监测系统的技术现状、发展前景及应用情况,阐述了No.7信令监测系统在公众电话网（国际国内电话网／智能网等）的网络维护管理工可以发挥的强大功能和多种应用。     

Electrochemically Induced Crystalline-to-Amorphous Transition of Dinuclear Polyoxovanadate for High-Rate Lithium-Ion Batteries

Polyoxometalates are intriguing high-capacity anode materials for alkali-metal-ion storage due to their multi-electron redox capabilities and flexible structure. However, their poor electrical conductivity and high working voltage severely restrict their practical application. Herein, the dinuclear polyoxovanadate Sr₂V₂O₇·H₂O with unusually high electrical conductivity is reported as a promising anode material for lithium-ion batteries. During the initial lithiation process, the Sr₂V₂O₇·H₂O anode experiences an electrochemically induced crystalline-to-amorphous transition. The resulting amorphous structure provides high redox activity and fast reaction kinetics via reversible V^4.9+/V^2.8+ redox couple through the intercalation mechanism. Furthermore, when coupled with the LiFePO₄ cathode, the strong V O bonds of the amorphous anode provide excellent structural stability, with the full-cell capable of performing >12 000 cycles with a capacity retention of 72%. Another advantage of Sr_2xV₂O_7-δ·yH₂O (0.5 ≤ x ≤ 1.0) is its composition adjustability, which enables delicately regulating the Sr vacancy content without destroying the structure. The defect Sr_2xV₂O_7-δ·yH₂O (x = 0.5) electrodes show significantly improved specific capacity and rate capability without sacrificing other key properties, delivering a high specific capacity of 479 mAh g^-1 at 0.1 mA cm^-2 and 41.9% of its capacity in 2 min. Overall, the preliminary study points the way forward for the facile preparation of high-quality polyoxometalates for advanced energy storage applications and beyond.     

1-氯-1,1-二硝基-2-(N-氯脒基)乙烷的合成、表征和晶体结构

采用高锰酸钾/盐酸体系氧化氨基的方法获得了1-氯-1,1-二硝基-2-(N-氯脒基)乙烷,收率为70%,用核磁、红外、质谱、元素分析等方法对该产物进行了结构表征.以二氯甲烷为溶剂制备出了其单晶,用X射线单晶衍射仪测定了晶体结构.结果表明,该化合物的分子式为C2H2Cl2N4O4,相对分子质量为216.98,该晶体为正交...     

多媒体内容描述接口--MPEG-7

国际标准化组织继 MPEG1、2和 4之后 ,又着手制定了 MPEG- 7标准。本文初步探讨了MPEG- 7的内容及应用范围 ,并讨论了 MPEG- 7与MPEG1、2和 4之间的关系     

PCI接口控制器CY7C09449及其应用

CY7C89449是Cypress公司开发的PCI协议主/从模式接口控制器.介绍了其功能特点及应用,并说明了引脚功能及配置注意事项.给出了一个机械手控制卡电路实例,旨在介绍如何利用CY7C09449实现PCI与TMS320C6711之间的数据传输.     

Analog Circuit Design Methodology in a Low Power RISC Microprocessor

There are various kinds of analog CMOS circuits in microprocessors. IOs, clock distribution circuits including PLL, memories are the main analog circuits. The circuit techniques to achieve low power dissipation combined with high performance in newest prototype chip in the Super H RISC engines are described. A TLB delay can be decreased by using a CAM with a differential amplifier to generate the match signal. The accelerator circuit also helps to speed up the TLB circuit, enabling single-cycle operation. A fabricated 96-mm² test chip with the super H architecture using 0.35-m four metal CMOS technology is capable of 167-MHz operation at 300 Dhrystone MIPS with 2.0-W power dissipation.     

基于USB接口的心电信号数据采集系统

介绍了基于USB接口的心电信号数据采集系统，给出了该系统的硬件组成原理及软件设计方法。由于该系统使用了高性能的USB专用芯片CY7C64613，因而具有使用方便、即插即用等特点。与笔记本电脑相连即可构成移动式心电信号检测分析仪器，具有较高的实用推广价值。     

Correlation of laser-beam-induced current with current-voltage measurements in HgCdTe photodiodes

Laser-beam-induced current (LBIC) is being investigated as an alternative to electrical measurements of individual photodiodes in a two-dimensional array. This is possible because LBIC only requires two electrical contacts to an array and the two-dimensional scanning of a focused laser beam across the array to image the entire array. The measured LBIC profiles, obtained from linear arrays of HgCdTe photodiodes, will be used to study the uniformity of photodiodes in the array and to extract the R₀A of the photodiodes. It will be shown that the shape of the LBIC signal is correlated to the electrical performance of the photodiode, with R₀A related to the spreading length of the photodiodes. Linear arrays of n-on-p, mid-wavelength infrared (MWIR) and long wave-length infrared (LWIR) devices were formed in liquid-phase epitaxy HgCdTe epilayers using a plasma junction-formation technique. The LBIC profiles were measured on each of the devices at various temperatures. For the MWIR devices, the extracted spreading length shows no correlation with R₀A. However, the LBIC signal does detect nonuniform devices within the array. For the case of the LWIR devices, the spreading length is extracted as a function of temperature, with the R₀A subsequently calculated from the spreading length. The calculated R₀A, obtained without requiring contact to each photodiode in the array, agrees well with electrical measurements. Asymmetry of the LBIC signals for certain devices in the arrays is shown to be a result of localized leakage at the photodiode junction or from the contact pads through the passivation layers. These results are confirmed by numerical modeling of the device structures.     

嵌入式技术在我国农电系统抄表中的应用

随着电力信息化建设的不断推进，用电营销管理在我国农电系统中得到迅速的普及和应用，为了摆脱电量数据的采集、传输环节上传统的手工抄表效率低下的困境，可以利用手持抄表器代替手工抄表。现提出了基于ARM7TDMI核的S3C44BOX微处理器芯片的手持抄表器的硬件系统设计方案，及其系统软件的实现。     

一类0-1背包问题的启发式网络策略模型与算法

针对遗传算法(GA)易陷入局部最优解、搜索精度低等缺点,提出了网络启发式策略的遗传算法(NSHGA),并将其成功地应用于0-1背包问题的求解。该算法采用网络节点关联策略,使算法具有良好的全局寻优能力。同时引入网络节点矩阵优化,利用其精细的局部遍历搜索性能,使算法具有较高地搜索精度。实例仿真结果表明,NSHGA算法可有效避免基本GA算法的早熟收敛,且具有寻优能力强、搜索精度高等特点。此外,与基本遗传算法仿真相比,可明显提高0-1背包问题求解的精度。