DESIGN ISSUES FOR BIT RATE-ADAPTIVE 3R O/E/O TRANSPONDER IN INTELLIGENT OPTICAL NETWORKS

IntroductionWith the rapid progress of Optical Add- DropMultiplexer and Optical Cross- Connect( OADM/OXC) technologies,itis becoming possible for car-riers to provide high- speed services such as OC- 48/OC- 1 92 and Gigabit Ethernet transmission chan-nels directly from the optical domain. Line speedsof electrical layer devices such as IP routers andATM switches are continually growing to satisfythe increasing demands of data,as evidenced bythe introduction of line card speeds of OC- …     

船舶无线电时钟浅析

根据STCW公约的要求,履行船舶无线电值班职责的无线电操作员应当至少每天校对一次无线电时钟,但是由于公约本身表达得不清楚以及我们理解的偏差,使得我们在履行无线电值班过程中遇到一些困难.本文详细地介绍了无线电时钟的概念,在此基础上介绍了如何正确地完成船舶的对时业务.     

xpMODEL: A Novel Model for ASIP Architecture

Introduction Various factors are making it increasingly dif-ficult and expensive to design and manufacture tra-ditional ASICs. In fact, there are signs of a revolu-tion afoot, with an increasing trend of engineersfrom hardware application groups going off…     

Hardware-Software Co-implementation of H.264 Decoder in SoC

Introduction H.264/AVC standard[1]significantly improvesthe video compression ratio and enhances the pow-er of video coding algorithms with increasing com-plexity. It has achieved a wide application in manyvideo fields, such as smart set-top box, video-based web browser, and videoconference etc. Image and video processing algorithms arehighly computationally intensive[2]. So they aremostly implemented by dedicated hardware archi-tecture. While with the increasing of parallel andpipelined pro…     

基于多端口串行Flash的超长条形LED显示屏控制

为了不增加硬件成本而提高显示数据的输出速度,在分析现有条形LED显示屏单元板电路的基础上,提出了一种基于多端口串行Flash存储器的LED显示控制系统,该系统由STC12C5616高速1T单片机和带SPI接口的SST26VF016B串行多端口Flash存储器组成.显示数据输出时,利用单片机的高速同步串行口(SPI)高速时钟,将多端口串行Flash存储器中的显示数据以"存储器直接存取(DMA)"的方式直接输出至超长条形LED显示屏.最后,以4 096×64点阵单色LED显示屏为例进行了测试.结果表明,显示屏刷新率达到62.5 Hz,验证了该系统在实际应用中的有效性和可行性.     

Influences of clock resolution of bandwidth measurement on packet pair algorithm

Influences of the clock resolution of bandwidth estimator on the accuracy and stability of the packet pair algorithm was analyzed. A mathematic model has been established to reveal the relationship between the result deviation coefficient and the packet size, clock resolution and real bandwidth（value）of the measured route. A bandwidth self-adapting packet pair algorithm was presented based on the mathematic model to reduce the estimation error resulting from the clock resolution and to improve the accuracy and stability of measurement by adjusting the deviation coefficient. Experimental results have verified the validity and stability of the algorithm.     

连铸连挤下注系统设计

本文推导出了连铸连挤机所采用的两级压头下注系统主要技术参数的实用计算公式,并据此设计制造了下注系统,工艺试验结果表明,该系统设计合理,具有实用价值。     

时钟同步技术及其在地铁综控系统中的应用

介绍当前城市地铁综控系统分层、分布式的特点,并指出保持全线站点时钟一致性的重大意义,分析当前世界上主要的GPS和NTP协议对时方式。最后针对地铁综控系统的网络拓扑结构和特点提出NTP协议和GPS相结合的时钟同步方案,测试结果证明这种混合对时方案基本可以满足地铁综合监控系统对时钟同步的要求,具有一定的应用价值。     

基于GPS时间源的自控时钟的设计与实现

分析了普通石英大钟时间源和控制方式技术上的不足,提出了以GPS为时间源,采用角度定位闭环控制的高精度自控时钟的设计思路。重点叙述了GPS信息格式和筛取时间信息的方法以及使用旋转变压器作角度定位的原理和实现方法。     

应用免疫组织化学方法评价组织芯片的可靠性

目的探讨组织芯片技术在免疫组化试验中的可靠性和提高组织芯片可信性的方法。方法选择82例人乳腺癌标本石蜡蜡块,利用传统制片技术和自行研制的专用器具分别制作常规石蜡切片和组织芯片,采用免疫组化技术检测雌激素受体(ER)、孕激素受体(PR)的表达。结果采用自行研制的专用器具制备组织芯片,所得样本的可分析率均在92.9%以上,且随着对同一标本取材数量的增加,其可分析标本率也明显上升。采用传统方法检测的82例乳腺癌标本中ER和PR的阳性率分别为61%和58.5%;采用组织芯片技术,一式一份取材,其阳性率分别为51.9%和50.0%,一式两份方式取材,其阳性率分别为53.8%和53.8%,采用一式三份方式取材,其阳性率分别为57.1%和60.7%,且三种不同取材方式的检测结果与传统制片法之间并无统计学差异(P>0.75)。结论在采用统一制备标准并保证组织芯片质量的前提下,挖取直径1.5mm的组织样本制备组织芯片,尽管组织芯片技术与传统方法检测的结果的一致率仍随着对同一标本取材次数的增加而提高,但是三种不同取材方式的检测结果之间并无统计学差异。因此,一式一份取材制备组织芯片完全可替代传统制片技术用于免疫组织化学乃至原位杂交、荧光原位杂交技术的研究,且可保证组织芯片的可信性和高通量特征。     

用于无线通信系统的信号强度检测电路设计

为了解决传统的信号检测电路准确度不高,对温度和工艺变化抵抗能力不够的问题,建立了信号强度检测电路的系统模型.推导得到限幅放大器增益与信号强度检测单元误差的关系以及降低信号强度检测单元误差的方法.通过分析,得到在提高准确度的前提下减小限幅放大器增益随温度和工艺变化的方法.基于以上分析,引入增益加强结构,以提高限幅放大器增益的准确性和抵抗温度及工艺变化的能力.采用0.18 μm体硅(CMOS)工艺,1.8 V供电电源,面积为500 μm×200 μm的电路进行测试,结果表明:测试温度从-40 ℃变化到85 ℃时,该信号强度检测电路都可以提供55 dB的动态范围和大于55 MHz的带宽,其检测误差小于1.5 dB,电路功耗为1.89 mW,检测精度高达1.5 dB.      

基于C/S结构的阅览室门控管理系统的实现

介绍了基于C／S结构的阅览室门控管理系统的设计、实现过程．系统基于C／S（Client／Server）模式运行．服务器端为阅览室管理模块．客户端为阅览室刷卡显示模块，每个客户端由一台PC机和一台读卡器构成．读卡器和PC机之间通过RS232口进行通信，使用CRC循环冗余校验码保证通信的准确性．数据库采用SQL Server2000系统，支持TCP／IP协议。     

桩核高度对下颌桩核基牙式全口覆盖义齿应力分布的影响

目的研究桩核高度对下颌桩核基牙式全口覆盖义齿及其支持组织应力分布的影响,为临床工作提供实验依据和指导。方法建立下颌桩核基牙式全口覆盖义齿及其支持组织的三维有限元模型,对义齿行全牙列垂直加载,分别计算当桩核根外段高度为3、4、5、6mm时义齿及其支持组织的应力值并进行比较研究。结果随着桩核根外段高度的增加,基牙牙本质、牙周膜、义齿基托及皮质骨的应力增大,黏膜的应力分布无明显改变。结论在保证义齿固位的前提下,应尽量降低桩核高度,维护组织健康。     

TGFβ1-(78-109)-HBc融合蛋白的原核表达

目的　应用基因工程技术制备TGFβ1 (78- 10 9) HBc融合蛋白 ,作为TGFβ1疫苗 ,用于抗纤维化研究。方法　合成TGFβ1 (78- 10 9)编码区DNA ,连接于质粒载体 ,再在其下游连接HBc编码区 ,测序证实后 ,进行原核表达 ,表达产物以SDS PAGE、ELISA等方法鉴定。结果　经DNA序列分析证实融合基因序列完全正确 ,SDS PAGE证实原核表达产物相对分子质量为 2 5kD ,ELISA检测证实TGFβ1 (78- 10 9)和HBc的抗原表位均可正确暴露。结论　本研究成功构建了TGFβ1 (78- 10 9) HBc融合基因 ,进行了原核表达 ,并初步证实了表达产物的抗原性 ,为下一步进行TGFβ1疫苗抗纤维化的研究打下了基础     

High Performance SAR ADC with Mismatch Correction Latch and Improved Comparator Clock

We propose a high performance 10-bit 100-MS/s(million samples per second)successive approximation register(SAR)analog-to-digital converter(ADC)with mismatch correction latch and improved comparator clock.Using a high-low supply voltage technology,the bias output impedance of the preamplifier of the comparator is increased.Therefore,the common mode rejection ratio(CMRR)of the comparator is improved,and further diminishing the signal-dependent offset caused by the input common-mode voltage variation.A digital-to-analog converter(DAC)control signal correction latch is proposed to correct the control signal error resulted from process mismatch.The 30-point Monte Carlo mismatch simulated results demonstrate that the minimum spurious-free dynamic range(SFDR)of the ADC is improved by 2 dB with this correction latch.To ensure sufficient high bit switching time of the DAC and sufficient low bit comparison time of the comparator,a data selector used in the comparator clock is presented.The optimized time distribution improves the performance of the SAR ADC.This prototype was fabricated using a one-poly-eight-metal(1 P8 M)55 nm complementary metal oxide semiconductor(CMOS)technology.With measured results at 1.3 V/1.5 V supply and 100-MS/s,the ADC achieves a signalto-noise and distortion ratio(SNDR)of 59.4 dB and consumes 2.1 mW,resulting in a figure of merit(FOM)of31 fJ/conversion-step.In addition,the active area of the ADC is 0.018 8 mm2.     

Experimental Study on the Compressive Behavior of CFRP/ECCs

In this study, nine square concrete columns, including six CFRP/ECCs and three plain concrete control specimen columns, were prepared. The CFRP tubes with fibers oriented in the hoop direction were manufactured with 10, 20, or 40 mm rounded corner radii at vertical edges. A 100 mm overlap in the direction of fibers was provided to ensure a proper bond. Uniaxial compression tests were conducted to investigate the compressive behaviors including the axial strength, stress-strain response, and ductility. It is evident that the CFRP tube confinement can improve the compressive behavior of concrete core, in terms of axial compressive strength or axial deformability. Based on the experimental results and some existing test database attained by other researchers, a design-oriented model is developed. The predictions of the model for CFRP/ECCs show good agreement with test results.     

IEC61850-9-2标准下合并单元的研制

针对当前合并单元的研究现状,分析了合并单元的采样值映射模型IEC61850-9-2及其实现方法,在此基础上设计了一种基于现场可编程门阵列(FPGA)的合并单元装置。该装置通过在FPGA芯片上配置NiosII软核处理器和相关接口,完成合并单元同步、多路数据接收和处理以及以太网通信等功能,能满足电子式互感器数字接口的要求。     

交通影响评价中存在的问题——以扬州市为例

目前,我国各城市纷纷进行交通影响评价,在扬州市规划局和交警支队等相关部门的指导下,扬州市于2006年开始了交通影响评价工作。在阐述了扬州市交通影响评价的实践过程及基本要素的同时,给出了交通影响评价报告的编制内容。最后,总结了扬州市交通影响评价中存在的问题。     

DETECTION OF PLASMA SOLUBLE INTERLEUKIN－2 RECEPTOR IN PATIENTS WITH SEVERE AND CHRONIC ACTIVE HEPATITIS B

ＤＥＴＥＣＴＩＯＮＯＦＰＬＡＳＭＡＳＯＬＵＢＬＥＩＮＴＥＲＬＥＵＫＩＮ－２ＲＥＣＥＰＴＯＲＩＮＰＡＴＩＥＮＴＳＷＩＴＨＳＥＶＥＲＥＡＮＤＣＨＲＯＮＩＣＡＣＴＩＶＥＨＥＰＡＴＩＴＩＳＢＺｈａｎｇＳｈｕｌｉｎ；ＷｕＧｕａｎｇｌｉ；ＹａｎＹｕｌａｎ；Ｃｈｅ...     

Experimental Study of the Controlling Characteristics of Inverter-Driven Multi-type Air Conditioner

The controlling algorithm was studied for the inverter-driven multi-type air conditioner using electronic expansion valve (EEV) in outdoor unit. The performance of inverter-driven air conditioner with two different units was investigated by varying the outdoor ambient temperature and compressor speed. Based on the test results, the effect of EEV opening on the indoor unit exit superheat was discussed. For the specified outdoor ambient temperature scope and the EEV opening, the superheats of indoor units decrease with the outdoor ambient temperature rising. Improper distribution of refrigerant into each indoor unit will causes excessive superheat difference between two indoor units. Suggestions were then given for the controlling of the superheat.