脉冲He—Ne激光用于斜弱视治疗

本文介绍了脉冲He-Ne激光治疗儿童斜弱视的光电原理、治疗方法与临床应用。     

集成本振小型化L 波段多通道组件

设计多通道变频系统时,需要在有限的设备空间内包含完整功能的模块。这就要求在满足性能指标的前提下,模块体积尽量小、功能尽可能多、集成度尽可能高。文中采用小型化频率源、射频信号穿墙技术并内置本振功分电路的方法,设计了一款变频组件。在保证功能以及性能的前提下,相比于传统设计方法,文中的设计方法有效将组件模块的体积减小为原来的70%、重量减轻为原来的50%,有利于系统的小型化以及通用化。经实物加工与测试,验证了该方案的可行性与实效性。     

PERFORMANCE OF TWO GENERALIZED ORDER STATISTICS CFAR DETECTORS WITH AUTOMATIC CENSORING TECHNIQUE IN MULTIPLE TARGET SITUATIONS

This paper presents two generalized modified OS-CFAR detectors and an automatic censoring technique. For these two new OS-CFAR detectors, analytic expressions of the false alarm rate, the detection probabilities and the measure of ADT under the Swerling 2 assumption are obtained. Their detection performances are analyzed in homogeneous background and in the presence of strong interfering targets, and they are compared with several previously proposed CFARs.     

PERFORMANCE OF MULTIUSER DETECTION FOR CDMA SYSTEM IN A FLAT RAYLEIGH FADING ENVIRONMENT

In a CDMA communication network using conventional signal detection, system capacity is limited and its performance is degraded by the multi-access interference (MAI). Multiuser detection, which makes use of cross-correlation information between spread spectrum codes, can reduce or eliminate the MAI in a Gaussian channel so as to mitigate the near-far effects and increase the system capacity. This paper extends the multiuser detector to a flat Rayleigh fading CDMA environment, and discusses the bit error rate of typical multiuser detection algorithms in such a environment by combining theoretical analysis and computer simulation. It is shown that multiuser detection is superior to conventional detections in the flat Rayleigh fading channels.     

微波遥感典型地物介电常数实地测量

在微波遥感定量化研究中,要求对遥感目标的介电特性有较准确的了解.为此采用自由空间法在野外实地测量典型目标的介电常数.给出了基本原理,定标方法及在X波段对黑土,草地,和冰所测的介电常数。分析比较了测量结果。     

两种改进的适用于多目标情况的恒虚警检测算法

本文基于筛选平均(CM)和无偏筛选平均(UCM)提出了两种改进的恒虚警检测器MCM-CFAR和MUCM-CFAR,并应用了何友(1994)提出的自动筛选技术.在Swerling Ⅱ型目标假设下,并考虑瑞利分布杂波和单脉冲检测情形,本文推导出了MCM-CFAR和MUCM-CFAR检测器的Pfa、Pd和平均判决门限(ADT)的解析表达式,并与其它方案进行了比较.分析结果表明,它们在均匀背景和多目标环境中的性能均明显优于GOSCA和OS;当IL=4,IR=2时,MCM-CFAR比OS改善了2dB,MUCM-CFAR也比OS改善了1.5dB;MCM的性能略优于CM,MUCM与UCM接近,但它们的样本排序时间不足CM、UCM和OS的一半,便于工程实现.     

酮苯装置用加氢裂化尾油生产优质白油料

加氢裂化尾油经溶剂脱蜡工艺生产出的高质量润滑油基础油,具有很好的低温流动性能,且对添加剂感受性好,硫、氮含量低,饱和烃含量高,可以调合中、高档润滑油,制备白油,综合利用加氢裂化尾油具有明显的经济效益。     

一种偏置集中力火箭舱体结构优化设计研究

为解决大型运载火箭助推器舱体结构承受偏置集中力问题,开展舱体结构优化设计研究.首先围绕舱段结构多工况、多约束的设计需求,采用多目标折衷规划实现舱体结构整体传力路径拓扑优化,根据拓扑优化结果设计一种"梁式"舱体结构,对舱体结构开展强度仿真分析,计算结果表明,"梁式"舱体结构可以提高整体承载能力14.2％,最后通过地面静力试验验证了舱体结构优化设计的正确性.     

A downlink beamforming assisted by locally positioned communication devices

Recently, multiple cell types with overlapping coverage have been deployed simultaneously to increase cellular network capacity. Cross‐tier interference is one of the key technical challenges in the use of this method. A simple and practical beamforming scheme assisted by locally positioned communication devices for the downlink of a multi‐cell wireless hierarchical cell structure system is proposed in this paper to maximize the capacity of the embedded small cell and simultaneously ensure minimal impact on the performance of existing macrocells. The locally positioned communication devices can be implemented with low complexity and at low cost and can continuously provide helpful and accurate information to base stations for the proper configuration of geographical cell coverage, allowing neighboring cells to cooperate effectively with each other. Simulation results verify that the proposed scheme can provide a significant gain over conventional systems not using the proposed algorithm. Copyright © 2013 John Wiley & Sons, Ltd.     

Bright Aggregation‐Induced Emission Dots for Dynamic Tracking and Grading of Patient‐Derived Xenografts in Zebrafish

Cancer prognosis will benefit from a scoring system that could grade malignant traits of patient‐derived cells by assessing their growth and metastasis in a living system. Specific tracking of patient‐derived cells requires labeling by contrast agents with good signal‐to‐noise ratio and no specific stain of host tissues. Towards this aim, aggregation‐induced emission (AIE) dots are developed for in vivo cancer tracking with emphasis on reproducible optimized formulation and specific fluorescent labeling of cells that enable enhanced spatial temporal resolution in vivo. The importance of energy‐dependent AIE dots uptake for patient‐derived cell labeling is emphasized to reveal their specific uptake by viable cancer cells. Using optically transparent zebrafish embryo, the ability is demonstrated to follow the engraftment of transplanted AIE dot labeled cells in zebrafish brains over one week. Cells detected outside the brain after 7 d are quantified as metastatic cells. Results from seven clinical samples demonstrate the utility of this methodology to differentiate low engraftment level of benign neoplasms from higher engraftment level and metastasis detected in malignant ovarian cancer specimens. Achieving clinically validated results supports the use of AIE dot labeled patient derived cells in zebrafish xenografts for future cancer prognosis.