用于肿瘤标志物现场快速检测的便携式仪表的研制

针对肿瘤标志物高灵敏度现场快速检测的需求,将电化学检测技术与电子技术相结合,采用差分脉冲伏安法(Differential pulse voltammetry,DPV)研制了一种可用于肿瘤标志物现场快速检测的便携式仪表,检测电压和电流的分辨率分别为0.8 mV和1nA.结合实验室自制微流控纸芯片,利用该便携式仪表对肿瘤标志物癌胚抗原(Carcinoembryonic antigen,CEA)进行检测,实验结果表明,在1～500 μg/L浓度范围内,DPV峰值电流响应与CEA抗原浓度对数呈线性关系,线性相关系数为0.998,检出限为10 pg/mL.根据抗原抗体特异性结合和电化学检测原理,检测到电化学反应的微弱电流后,仪表可以根据已经标定的电流与浓度之间的比例关系自动计算出肿瘤标志物的浓度.此便携式仪表具有检测灵敏度高、检出限低等优点,可广泛应用于肿瘤标志物的即时检测.     

用Monte Carlo方法模拟闪锌矿相ZnS电子的输运特性

用Monte Carlo方法模拟闪锌矿相(zinc blende)ZnS电子的输运特性.实验采用的是非抛物线模型计算电子的能带结构,模拟包含了声学声子散射,极性光学声子散射,压电散射,电离杂质散射,能谷间散射以及自散射等散射机理.通过模拟得到了ZnS材料的平均漂移速度、平均电子能量随电场强度变化的曲线图,以及总散射率随电子能量变化图,并将结果与文献报道的模拟结果[1]进行比较得出:本实验方法具有模型简单,计算速度快,获得结果比较准确的优点.     

M2 factor of four-petal Gaussian beam

Based on the second-order moments, this paper derives an analytical expression of the M^2 factor of four-petal Gaussian beam. The results show that the M^2 factor is only determined by the beam order n. The corresponding numerical calculations are also given. As the beam order increases, the augment of M^2 factor is disciplinary. As the expression of M^2 factor is expressed in series form and becomes more complicated, a new concise formula of M^2 factor is also presented by using curve fitting of numerical calculations. When 3 ≤ n ≤ 200, the maximum error rate of fitting formula will not exceed 2.6% and the average error rate is 0.28%. This research is helpful to the applications of four-petal Gaussian beam.