"勇气"号火星车的全景照相系统分析

“勇气”号火星车在火星的顺利着陆与发回的大量三维全景照片引起了世人的关注〔1〕。本文详细的介绍了火星车上的三维全景照相系统的工作原理和系统结构,分析了三维全景照相设备的主要构成和关键技术参数,分析了全景照相机的参数标定方法和装置。本文还从双目视觉的基本原理和计算公式出发,从全景照相系统提供的一对双目照片中提取了部分火星表面的视差图。     

Direct generation of subpicosecond chirp-free pulses at 10 GHz froma nonpolarization maintaining actively mode-locked fiber ring laser

0.7-1.3 ps highly stable, transform-limited, sech²-shaped pulses at 10 GHz in the 1536-1569 nm wavelength region from a nonpolarization maintaining (PM), single intensity modulator, actively and harmonically mode-locked fiber ring laser have been directly generated. Little degradation of long-term stability of the laser operation was observed due to the non-PM nature of the laser cavity     

RC正弦波振荡电路教学设计

本文以8音阶简易电子琴电路引入,从信号产生和8音阶实现两个问题入手,引出RC正弦波振荡电路理论,并拓展应用到实现简易电子琴的设计.通过全员参与,步步设疑,层层探究,理论与应用结合,激发了学员兴趣,提高了学员能力.     

长波长GaInNAs垂直腔面发射激光器

新出现的直接跃迁GaInNAs与具有高反射率的AlAs／GaAs分布布拉格反射镜相结合构成了GaAs基长波长(1．3—1．6μm)垂直腔面发射激光器(VCSEL)，将成为光纤通信、光互联和光信息处理等的关键元件。本文从材料的选取、外延技术和GaInNAs VCSEL国外和国内的发展状况等方面对长波长GaInNAs VCSEL进行了综合阐述。     

密码协议的健全性分析

“健全”的密码协议，可以抵抗多种类型的攻击，建议作为密码协议设计的一个准则，这将有助于协议的早期分析，部分地弥补ＢＡＮ逻辑的不足。     

业务财务一体化需求分析思路与方法研究

首先介绍电信运营商实施业务财务一体化的外部驱动力及意义,然后介绍3种实施业务财务一体化的需求分析思路与方法,最后给出电信运营商业务财务一体化实施方法建议及对实施难点的探讨。     

驱动复杂RLC互连树的逻辑门延时

提出了一个用于估计RL C互连树驱动点导纳的闭端等效π模型,并将其用于驱动复杂RL C互连树的逻辑门延时的估计中.与其他方法相比,它具有结构简单、精度较高的特点     

Self-service reservation in the fieldforce

On-line service reservation is becoming increasingly popular in the service industry. As services become more complex, requiring co-ordination among individual actions, the planning for making service appointments is normally conducted manually by the operators, often resulting in slow responses to customers. To tackle this problem, we have developed a real-time service reservation portal that takes an order from a user and works out appointment options, based on the availability of enterprise resources, for the user to book on-line. The portal is capable of dealing with complex workflow appointing, supporting interactive fine-tuning in individual appointments, respecting customer preferences and work policies, monitoring progress of workflow, informing the customer of status changes in job scheduling, dispatching and execution, as well as handling exceptions automatically. We have integrated the portal, code-named FieldReserve, with other components in the BT fieldforce optimisation suite (FOS) that covers functions of resource planning, scheduling and execution for the fieldforce to demonstrate the feasibility and potential benefits of this technology. Benefits demonstrated are to provide customers with instant response of service reservation, to provide volume control on reservation, to break away from one-size-fits-all lead times for service fulfilment, to provide customers with equal access to service provision, and to bring transparency of service progress to customers. Currently, we are actively engaging with businesses and have obtained strong support to downstream the key values of this technology in commercial contexts.     

RTD/HEMT串联型RTT的设计与研制

依据RTD/HEMT串联型RTT的概念,设计了RTD/HEMT单片集成材料结构,该结构采用分子束外延技术生长.采用湿法化学腐蚀、金属剥离、台面隔离和空气桥互连技术,研制了RTD/HEMT串联型RTT,并对RTT及RTT中RTD和HEMT的直流特性进行了测试.测试结果表明:在室温下,器件具有明显的栅控负阻特性,正接型RTT的最大峰谷电流之比在2.2左右,反接型RTT的最大峰谷电流之比在4.6左右.实验为RTD/HEMT串联型RTT性能的优化和RTD/HEMT单片集成电路的研制奠定了基础.     

短脉冲激光辐照的非傅里叶热力耦合效应

将非傅里叶耦合热弹性方程无量纲化得到了通用的表征热力耦合效应的无量纲数λ;通过分析比较无量纲非傅里叶耦合与非耦合热弹性方程的级数解,研究了短脉冲激光辐照的非傅里叶热力耦合效应的特性.发现热力耦合不仅使光致热应力波较非耦合的波速增大,波长变长,波幅在传播过程中不断衰减,并使该应力波激发出与其速度相同的第二温度波.不论耦合与非耦合,应力波随参数ε的变化均具有饱和特性且在某一条件下呈现奇异的双峰波形.热力耦合效应的强弱主要取决于λ;另外还取决于脉冲触发后经历的时间和脉冲底宽之比,比值越大,耦合效应越强.因而对于超短脉冲激光辐照情况,在通常λ的绝对值较小(10-3量级及以下)的情况下,忽略热力耦合效应也可能会导致较大误差.