以易控的工艺条件为基础，通过设计简易实验装置来模拟锆合金在实际生产中的张力退火过程。采用X射线衍射（XRD）和电子背散射（EBSD）技术，对不同温度和不同张力下退火处理后的Zr–4合金织构和再结晶行为进行研究。结果表明，施加外加应力和提高退火温度可显著改变再结晶织构演化过程。随着外加应力值的增加以及退火温度的升高，锆合金的主要织构($\\overline 1 2\\overline 1 5$

Improving performance of coherent coded It can be shown that if the channel estimates are perfect(a1=a1, a2 OFDM systems using space time transmit a2)diversity can be achieved

IEEE TRANSACTIONS ON COMMUNICATIONS. VOL 50. NO. 1 JANUARY 2002 LDPC-Based Space-Time Coded OFDM Systems Over Correlated Fading Channels: Performance Analysis and Receiver design Ben Lu, Student Member, IEEE, Xiaodong Wang, Member, IEEE, and Krishna R Narayanan, Member: IEEE AbstrackWe consider a space-time coded (STC) orthogonal systems integrate the techniques of antenna array spatial diver-

Introduction Frequency-selective fading is a dominant impairment in mobile communications Fading reduces receive signal-to-noise ratio and degrades the bit-error-rate(BER) Frequency selectivity of the channel, i. e, delay spread, induces inter-symbol interference(ISI) To combat frequency-selective fading

INFORMATION TO USERS This manuscript has been reproduced from the microfilm master UMl filt the text directly from the original or copy submitted. Thus, some thesis dissertation copies are in typewriter face, while others may be from any type of coMm

第五章同步时序逻辑电路 本章知识要点: 一、时序逻辑电路的基本概念; 二、同步时序逻辑电路的分析和设计方法; 三、典型同步时序逻辑电路的分析和设计

Chapter Three Telecommunication Technology Chapter Study Tasks (3) In this chapter, you will be able to Identify the key concepts of telecommunication -Learn the basics of data and serial communications -Get the general ideas of the text and the extensive reading -Complete all the practice required

4.1设计前的准备 4.2系统设计原则与步骤 4.3工作区子系统设计 4.4水平子系统设计 4.5管理子系统设计 4.6垂直干线子系统设计 4.7设备间子系统设计 4.8建筑群子系统设计 4.9其它系统的设计 4.10图纸设计 4.11综合布线系统设计方案 4.12学生宿舍网络综合布线系统设计方案

Chapter Two Sensing Technology Chapter Study Tasks (2) In this chapter, you will be able to -Get the general idea of remote sensing -Tell the difference between passive and active sensors -Get the general ideas of the texts and extensive -Complete all the practice required

一、无线寻呼系统的组成及工作原理。 二、集群系统的概念、网络结构及发展趋势。 三、移动卫星通信系统的分类及各相关的系统组成。 四、全球星手机的号码结构