三维医学图像配准在图像引导放疗中的应用

为了确定病人的摆位误差,实现精确放疗,提出一种改进的Demons弹性配准算法。采用FDK算法对锥形束CT(CBCT)图像进行三维重建,利用可视化工具包 (VTK)体绘制法可视化重建结果;在分割与配准工具包 (ITK)基础上实现Demons算法,并基于对称梯度的思想,将参考图像和浮动图像的梯度场信息加入到Demons算法中,给出新的Demons形变力公式。分别使用单模态和多模态医学图像进行配准实验,结果显示改进的Demons算法与原始Demons算法相比,配准速度更快、精度更高。基于对称梯度的Demons算法更适用于图像引导放射治疗中CBCT重建图像与CT计划图像间的配准。     

MCNP源子程序在停机剂量率计算中的应用

在核聚变装置的停堆剂量率的计算中,通常采用MCNP程序来实现光子的输运计算,但由于聚变装置几何和材料的高度复杂性使得栅元数量庞大,同时由于标准MCNP在进行光子输运计算时,SDEF通用源卡只支持1 000个以下的栅元描述,因此直接采用SDEF通用源卡的方法无法实现聚变堆的停堆剂量率精确计算与分析。本论文采用MCNP内置源子程序方法直接对衰变光子源进行抽样,解决了SDEF通用源卡受限的问题。以国际热核聚变实验堆ITER最新发布的停机剂量率基准例题以及ITER-T426基准实验例题对源子程序进行了校验,结果表明了该方法的可用性与正确性。     

Behaviors of Electron Heat Transportation in HT-7 Sawtoothing Plasma

It is found that in HT-7 ohmic plasma, main energy loss comes from electron heat conduction, hence quantitative data of electron heat diffusivity is a very important issue for investigation of electron heat transportation behavior in different target plasmas so as to get high performance plasma. A time-to-peak method of the heat pulse propagation originating from the sawtooth activity on the soft x-ray intensity signal has been adopted to experimentally determine electron heat diffusivity χe^HP on the HT-7 tokamak. Aiming to improve the signal-to-noise (S/N) ratio of the original signal to get a stable and reasonable electron heat diffusivity χe^HD value, some data processing methods, including average of tens of sawteeth, is discussed. The electron heat diffusivity χe^HP is larger than χe^PB which is determined from the balance of background plasma power. Based on variation of the measured electron heat diffusivity χe^HP , performances of different high confinement plasmas are analyzed.     

数字化白光扫描干涉仪的研究

研究并设计实现了微形貌测量白光扫描干涉仪系统和光纤偏振耦合点监测白光扫描干涉仪系统.前者采用Mirau相移干涉形式,用压电陶瓷传感器PZT作移项器,主要用于微形貌测量,精度可达nm量级.后者采用光路补偿白光Michelson干涉形式,用格兰棱镜对偏振态进行调整控制,用移动参考臂来补偿由于耦合点所造成的光程差,光纤寄生偏振耦合测试仪的空间分辨率达到50mm,测量范围达到1km,探测灵敏度不小于-80dB(耦合模式与主模式的功率比).     

强化规划体系创新,加快规划方式转变 科学推动华东坚强智能电网建设迈上新台阶

通过对华东电网30年发展历程的全面回顾,指出电网规划必须满足于电网发展的客观需要.针对当前电网发展的内外部环境,华东电网有限公司全面启动以"四化"为特征的坚强智能电网建设,创新规划体系,突破关键技术,开展多适应性电网规划优化体系研究势在必行.在分阶段制定规划方式转变路线图的基础上,提出了围绕自愈、安全、经济、清洁和优质五个重要方面,提升电网规划能力,加强核心技术攻关的重点工作.     

Removal of NO and SO2 in Corona Discharge Plasma Reactor with Water Film

In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water, and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NO~ removal under suitable conditions is obtained in our experiments.     

新铜试剂-铜(Ⅰ)体系萃取原子吸收法间接测定微量硫酸根的研究

本文研究[Cu(NCP)_2]O_2~(2+)SO_4~(2-)离子对的形成和萃取条件,对反应体系中pH值、羟胺、甲醇等的用量以及振荡时间、放置时间等因素做了选择实验,提出了它们对反应体系的影响。     

视频信号的实时小波压缩芯片ADV611及其应用

介绍了美国AD公司新推出的专用视频图像压缩/解压缩芯片ADV611的结构特点和工作原理,并详细介绍了基于ADV611和DSP芯片TMS320VC5402的实时视频图像传输系统方案,目前该方案已经用于某部队的哨位监控系统.     

超宽带无线通信系统的调制方式研究

超宽带技术是目前无线通信中非常有发展前途的技术.本文介绍了超宽带通信的基本原理,着重分析了目前使用的几种调制方法,简要说明了各种调制方法的频谱特性,并比较了这些调制方法的性能.