均匀磁化永磁棒的磁场

本文综合运用分子电流观点及磁荷观点,系统地计算了沿轴向、横向及其它任意方向均匀磁化的有限长永磁棒在轴线上的磁场以及无限长永磁棒在全空间的磁场.     

基于LED的标准太阳光谱灯拟合算法

在测量领域中需要使具有高稳定性及良好光谱匹配性的人工模拟太阳光谱标准灯.本文提出一种基于多种不同峰值波长LED光源的方法来准确模拟AM1.5的光谱分布.以最小二乘法和高斯分布数学模型为基础,在理论上实现了非均匀间隔峰值波长的光谱拟合,从而指导LED的种类选择及其所需的驱动电流值,并通过实验论证其可行性.结果表明:在300～1100 nm的范围内,使用较少LED种类的情况下,此方法光谱失配误差小于±2.76％.此算法可精确地分辨标准太阳光谱AM1.5的吸收谷,且应用于AM0的拟合时获得小于±1.67％的光谱失配度.在工程实践中,该算法对快速、准确获得标准太阳光谱灯具有良好的指导意义.     

QuEChERS/液相色谱－串联质谱测定猪肉中赛拉嗪及其代谢产物2，6-二甲基苯胺

建立了QuEChERS/液相色谱－串联质谱测定猪肉样品中赛拉嗪及其代谢产物2,6-二甲基苯胺（DMA）的新方法。样品匀浆后经乙腈－2%乙酸提取、C18吸附剂/N-丙基乙二胺（PSA）净化处理,提取液经氮吹、定容后,以0.1%甲酸－水溶液和0.1%甲酸－乙腈溶液为流动相,采用Waters C18色谱柱（100 mm × 2.1 mm,3.5 μm）进行分离,正离子模式下多反应监测模式检测,基质匹配外标校准曲线定量。赛拉嗪和DMA的线性范围均为0.2～500 μg/L,检出限分别为0.10、0.30 μg/kg,定量下限分别为0.32、1.00 μg/kg,加标回收率分别为95.6%～108%和70.3%～79.5%,相对标准偏差（RSD）分别为2.6%～2.8%和3.1%～5.0%。该方法成功应用于市售猪肉中赛拉嗪和DMA的检测,为肉制品中赛拉嗪和DMA的检测提供了一种简单、快速、灵敏的新方法。     

Design of data acquisition system and algorithm research for omnidirectional gamma-ray positioning equipment

This article introduces the design and performance of the data acquisition system used in an omnidi- rectional gamma-ray positioning system, along with a new method used in this system to obtain the position of radiation sources in a large field. This data acquisition system has various built-in interfaces collecting, in real time, information from the radiation detector, the video camera and the GPS positioning module. Experiments show that the data acquisition system is capable of carrying out the proposed quantitative analysis to derive the position of radioactive sources, which also satisfies the requirements of high stability and reliability.     

由习题引发的思考——关于直线与圆相交的又一判定方法

已知⊙O'的圆心坐标为(1,1),半径为1/(1/2)则⊙O'与一次函数.y=3~(1/3)x 1的图像位置关系是____. 这道题初看起来,不     

Design of data acquisition system and algorithm research for omnidirectional gamma-ray positioning equipment

This article introduces the design and performance of the data acquisition system used in an omnidirectional gamma-ray positioning system, along with a new method used in this system to obtain the position of radiation sources in a large field. This data acquisition system has various built-in interfaces collecting, in real time, information from the radiation detector, the video camera and the GPS positioning module. Experiments show that the data acquisition system is capable of carrying out the proposed quantitative analysis to derive the position of radioactive sources, which also satisfies the requirements of high stability and reliability.