基于特征融合的手背静脉识别

图像平移和旋转会降低手背静脉识别的准确性,针对该问题,本文提出了一种特征融合的手背静脉识别法.该方法充分考虑图像的细节特征和全局特征,首先选取图像中的交叉点和端点作为特征点,再从特征点中提取出图像匹配的基准点,计算基准点至特征点间的相对距离及基准点与特征点连线间相邻连线产生的夹角作为细节特征;然后利用不变矩方法提取图像特征作为全局特征;最后将两种图像特征融合,进行手背静脉识别.实验模拟结果表明,该方法可快速有效地实现手背静脉识别.     

霍尔槽实验在电镀填孔中的应用

通过对霍尔槽规格设置和填孔铜槽槽液调整,用霍尔槽实验确认电镀铜填孔槽光泽剂和整平剂浓度。     

基于步行者航位推算的井下人员辅助定位

针对目前井下人员定位系统存在的问题,提出一种基于步行者航位推算的辅助定位方法。利用低成本的惯性测量单元(IMU)和磁力计,设计稳定的姿态与航向参考系统(AHRS),利用惯性导航的相关理论,并通过分析人员步行姿态,进行零速修正(ZUPT),组成步行者航位推算系统,对井下人员进行实时航位推算。以实验室大楼走廊模拟井下矿道环境进行航位推算实验,实验结果表明,本方法对人员行走距离和方向做出良好的推算,能成为现有井下定位的有效补充,提高人员定位精确度。     

甲基苯丙胺标准物质的定值与不确定度分析

为了建立法庭科学毒品检测量值溯源体系,研制了甲基苯丙胺纯度标准物质。通过红外光谱、质谱法对甲基苯丙胺样品进行定性分析,优化并建立了高效液相色谱(HPLC)、差示扫描量热法(DSC)两种定值分析方法。采用热重分析法和电感耦合等离子体质谱法测定水分和无机离子的含量。通过均匀性与稳定性检验结果表明,甲基苯丙胺标准物质的均匀性良好,稳定性至少1年,同时对其进行了不确定度评定。研制的甲基苯丙胺标准物质的纯度为99.8%,扩展不确定度为0.2%(k=2)。     

Application of Ion-Selective Electrodes as Reference Electrodes

Abstract

Reference electrodes limiting interfering effects of conventional reference electrodes on the measurement involving ion-selective electrodes have been developed. They are constructed of a plastic body with porous plug or sleeve junction. Solid state, low impedance, ion-selective electrodes (cupric, cadmium, fluoride) in the equilibrium of corresponding ion solution are used as the half-cells. The absence of interfering ions in the electrolyte allows the determination of the ion of interest at extremely low levels without interference. The electrodes have good reproducibility and stable intercomparison potentials of ± 0.2 mV. The performance of the electrodes has been tested for the measurement of sub-ppm halide levels. Data on stability, reproducibility, effects of temperature, ionic strengthand pH is presented and compared to that of conventional reference electrodes.     

Water-Phosphoric Acid Media: Electrochemical Properties

Abstract

Electroactivity ranges at polished Platinum, vitreous Carbon, and Mercury electrodes are determined in H₂O - H₃PO₄ mixtures (0.1 -14 M H₃PO₄). The Ferrocene system is considered as a comparison system. Ag⁺/Ag_s and AgCl/Ag_s systems are considered as reference systems. The R_o(H) acidity function is determined. It varies from -2.0 to -6.0 when H₃PO₄ varies from 5.5 to 11.5 M.     

Chemical Shift Reference for MASSCP-13C NMR Studies of Reagents Immobilized on Silica Gel

Abstract

This report demonstrates that immobilized trimethylsilane is an appropriate reference standard for MASSCP-¹³C NMR studies of reagents immobilized on silica gel. An example is presented which shows that the immobilized trimethylsilane exhibits many of the advantages as a reference for these solid samples as does tetramethylsilane for liquid samples. It is further shown that pure solids may interact with an immobilized phase and produce significant spectral changes and thus are not appropriate as reference standards.     

A Reference Optical System of Laser Doppler Longitudinal Displacement Measurement

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2DW_(232-236)~(14-18)型硅电压基准二极管的研制

本文介绍了２ＤＷ_（２３２－２３６）~（１４－１８）型硅电压基准二极管的研制过程及研制结果。     

激光引信数据采集处理系统的研制

文中介绍了为建立目标和背景的激光反射特性数字模型而研制的用于脉宽几十纳秒的数据采集系统的设计和工作方式。针对测量窄脉冲信号幅值及实现不间断连续采集过程的使用目的,将窄脉冲回波信号的身值展宽成100us的方波,以系统设置的发射 基信号或回波信号自身作为采集的同步控制信号,并将基准信号展宽为5-50us的方波,以其上升沿触发采集,实现发射与采集同步,提高了采集存储的有效性;而且,在作用距离范围内,不管目标或背景位于多远处,都能保证于脉宽峰值处采集,保证了采集精度。系统的各项技术指标均达到使用要求并经过了测试试验验证。