一种预测低层大气折射率剖面的实用方法

提供了一种实用的低层大气折射率剖面的短时预测方法。针对一天中折射率变化最为剧烈的日出日落前后的大气折射率剖面的试验测试，使用这个方法进行了预测。它用微波折射率仪等精密空气折射率测量设备测得的时变参数推算未来２－３ｈ的低层大气折射率剖面，结果表明预测结果和实测的大气折射率剖面相吻合。     

Determination of 8[(3S)-3-amino-1-pyrrolidinyl]-1-cyclopropyl-7-fluoro-9-methyl-4-oxo-4H-quinolizine-3-carboxylic acid hydrochloride and related substances by high performance liquid chromatography

Summary The purity of the investigational antibacterial Abbott-086719.1 (I) which is 8[(3S)-3-amino-1-pyrrolidinyl]-1-cyclopropyl-7-fluoro-9-methyl-4-oxo-4H-quinolizine-3-carboxylic acid hydrochloride is determined using gradient elution HPLC. The chromatographic separation was optimized and the chromatographic parameters critical to separation are discussed in detail. Most acceptable separations were achieved using an Alltima C18 column (5 μm) measuring 4.6 mm I.D. × 15 cm with 0.01M–0.03M citrate eluents which were modified with acetonitrile or with mixtures of acetonitrile and methanol. Related substances in I were determinable to 0.05 %. Repeatability (RSD values) for determining related substances at levels of 0.50 to 0.06 % ranged from ±1.9 to ±10 %. Determinations of I in 5 % dextrose in water and in hydroxypropyl methylcellulose were made using the same column and a simple isocratic system. The determination of I was stability indicating with precision (RSD values) of ±0.5 % to ±2.0 % and good agreement with theory for formulations containing I at 1.0 to 95 mg/mL concentrations. Recoveries of I from the vehicles were quantitative and linearity of the detector response of I was demonstrated to at least 0.10 mg/mL.     

基于核主分量相关判别分析特征提取方法的目标HRRP识别

为有效提高雷达高分辨1维距离像目标识别系统的总体性能,需要对目标高分辨1维距离像进行特征提取,以得到具有最小信息损失、高可分性且低维度的目标特征,为实现该目的提出一种基于核主分量相关判别分析的特征提取算法。该算法基于目标高分辨1维距离像的统计特性,通过对核主分量分析中核函数的选择,实现对不同类型距离单元的特征提取。同时综合线性判别分析与典型相关分析理论构建新的准则函数,以实现特征空间中类内相关性与类间差异性最大化,同时减少目标特征中的冗余信息。利用实测数据进行实验,结果表明该方法提高了特征向量的可分性,降低了特征向量的维度,并且对该算法在不同强度杂波下的识别性能进行了分析,实验结果表明,该方法可以有效的提高目标高分辨1维距离像目标识别系统的总体性能。     

浅海复杂环境下等效声速剖面的构建方法*

针对浅海复杂环境声速剖面水平变化情况下的声传播损失预报及目标定位问题,提出了一种基于遗传算法的等效声速剖面重构算法。首先,将声速剖面进行时间和空间上的分解,从而将声速剖面抽象为对声速剖面前三阶正交函数系数的反演;其次,利用遗传算法,以先验声速剖面集为基础,进行参数反演。仿真结果表明,在浅海复杂条件下,传播损失预报受声速剖面及海洋参数的影响,不能直接运用接收或发射位置处的声速剖面进行传播损失预报,否则会对预报结果造成误差。通过构建具有声传播累积效应的等效声速剖面可以提高匹配场定位精度,完成目标定位,且在构建等效声速剖面时,接收位置处即本地声速剖面所占权重较大。     

表面强化处理尖轨的廓形优化设计

在对尖轨进行表面强化处理后,其表面硬度和耐磨性大幅提高,为进一步提高尖轨使用寿命,降低轮轨接触应力和磨耗,需要对既有尖轨廓形进行优化.结合现场实际和实测车轮数据,提出不同轨顶坡角度,并选择在不同断面进行建模计算.通过比较不同轨顶坡和接触应力及接触斑面积分析得出1:20为最优的轨顶坡角度,并选择与之匹配的轨距角半径为13mm,从而提出优化后的尖轨廓形.     

硬盘录像机在数字转播车中的应用

以实际应用为基础简略介绍了PDR204D硬盘录像机及其在数字转播车中的多种应用。     

辉光放电光谱分析技术在金属材料分析中的应用

本文主要介绍了辉光放电光谱仪的基本原理,分析特点以及在金属材料分析中的应用,并从理论上推导出辉光放电光谱分析技术用于金属材料分析的理论依据。着重介绍了基板分析、深度逐层分析。对磷青铜镀银层逐层分析;渗碳、氮钢板分析;彩涂钢板分析进行了探讨。     

Digital correlation of grainy shadow images for surface profile measurement

An optical method, combining the projection of a structured light pattern with the digital correlation technique, is discussed in this paper. This method allows measurement of full-field profile on object surface of about 20 mm square size. Tests on a rotated plane surface have been performed in order to quantify the method capabilities. It is shown that this technique leads to an accuracy of about 1 μm for a spatial resolution of around half a millimeter. Profile measurements of a micro-engraved object and at the crack tip of a polymer sample are also presented. Results give proof that this technique remains efficient even in presence of important height slope.