A capacitive sensor based on molecularly imprinted polymers and poly(p-aminobenzene sulfonic acid) film for detection of pazufloxacin mesilate

A novel capacitive sensor for pazufloxacin mesilate (pazufloxacin) determination was developed by electropolymerizing p-aminobenzene sulfonic (p-ABSA) and molecularly imprinted polymers (MIPs), which was synthesized through thermal radical copolymerization of metharylic acid (MAA) and ethyl-ene glycol dimethacrylate (EGDMA) in the presence of pazufloxacin template molecules, on the gold electrode surface. Furthermore, 1-dedecanethiol was used to insulate the modified electrode. Alter-nating current (ac) impedance experiments were carried out with a Model IM6e to obtain the capaci-tance responses. Under the optimum conditions, the sensor showed linear capacitance response to pazufloxacin in the range of 5 ng·mL-1 to 5 μg·mL-1 with a relative standard deviation (RSD) 5.3% (n=7) and a detection limit of 1.8 ng·mL-1. The recoveries for different concentration levels of pazufloxacin samples varied from 94.0% to 102.0%. Electrochemical experiments indicated the capacitive sensor exhibited good sensitivity and selectivity and showed excellent parameters of regeneration and stabil-ity.     

高速高压超短脉冲在容性负载上的测量及分析

高速高压超短脉冲在多个领域具有广泛的应用。利用传输线终端反射的原理和高速开关产生高速高压的超短脉冲信号是一种通用办法。然而，当脉冲信号加载到一个容性负载时，终端负载的不匹配会导致信号的反射。反射信号可能再次回到负载器件上，形成二次导通，并带来应用上缺陷。本文通过理论分析和仿真实验，提出了一些改进措施，可以有效抑制反射信号。     

Design of a capacitive main power coupler for RF superconducting accelerators

An updated main coupler has been designed for the superconducting accelerator of Free Electron Laser (FEL) project under construction in Peking University. A capacitive structure is chosen for the main coupler. Numerical investigation using CST Microwave Studio demonstrates the cold window part. The other nonstandard structures such as holding rods and antenna are also optimized. The coupler uses a 95% purity Al2O3 ceramic cold window. The VSWR (Vottage Standing Wave Ratio) is 1.02 at 1.3 GHz and the frequency bandwidth is 45 MHz with VSWR<1.1. The electric field intensity is 8.5×10m-2 kV/mm around the window with 20 kW Continuous Wave (CW) transmitted power. The Qext is designed variable from 5×106 to 1×107.     

新型宽带容性馈电微带天线单元仿真设计

设计一种新型宽频带微带天线单元.天线采用空气介质腔,通过容性馈电贴片进行同轴线馈电,并进行边缘开槽.通过采用HFSS高频系统仿真软件仿真分析发现,适当的调整天线切口、空气腔体和馈电贴片的长宽可以调整天线的带宽和驻波比性能.以反射系数S11≤-10 dB为标准,可测得天线的阻抗带宽达到50%,覆盖4～6 GHz,并且通过改变馈电贴片宽度或空气腔体宽度可以实现天线的双频特性.     

CMOS工艺兼容的温湿度传感器

设计并制备了一个CMOS工艺兼容的温湿度传感器,讨论了感湿理论模型并用COVENTOR软件进行了模拟,给出了具体的结构参数及工艺制作步骤,最后对温湿度传感器进行了测量,对理论值和实际测量值做了比较并给出了分析结果．结果表明,传感器在25℃时的灵敏度为0.015pF/%RH,从15％RH～95％RH,电容实际变化量为1.23pF．     

电容式绝对压力传感器的改进模型及温度特性分析

在传感器敏感膜模型的基础上对电容式绝对压力传感器提出了一种改进模型,考虑了由于温度的变化电容结构空腔中残余气体对传感器性能产生的影响．结果表明温度的改变会导致残余气体压力的改变,进而使传感器的测量产生一定的温度漂移,同时也降低了传感器的灵敏度;并由此计算了残余气体存在时,传感器测量值的温度漂移量以及灵敏度的温度系数．这对于工艺的改进以及后续电路的设计具有指导意义．     

分步磁控溅射ZnO和/或功能化碳纳米粒子修饰ZnO电子传输层增强聚合物太阳能电池效率

氧化锌具有良好电子传输性和高透光性,ZnO作为电子传输层已被广泛应用于聚合物太阳能电池。但采用溶胶凝胶法和真空镀膜制备ZnO电子传输层,因ZnO界面具有大量缺陷,极大增加载流子复合。抑制ZnO界面复合电流和改善ZnO界面接触性能,是提高ZnO基电子传输层聚合物太阳能电池性能关键所在。基于P3HT:PCBM反转型聚合物太阳能电池,采用磁控溅射ZnO层,研究了离子液功能化碳纳米粒子(ILCNs)修饰层或Ar/O₂混合气体溅射沉积ZnO修饰层,以及Ar/O₂溅射ZnO界面层与ILCNs联合修饰ZnO界面的聚合物太阳能电池性能。纯Ar和Ar/O₂混合气体下一步溅射沉积ZnO电子传输层,其电池效率分别为2.2%和2.8%。经ILCNs修饰或Ar/O₂溅射ZnO修饰层,电池效率分别达到3.4%和3.1%,并且分步溅射ZnO层并联合ILCNs修饰ZnO界面,聚合物太阳能电池效率可提高到3.8%。ZnO修饰型聚合物太阳能电池克服了电化学阻抗负阻效应,降低了反向暗电流并显示出更好的整流特性。研究表明,采用ILCNs修饰ZnO层和分步溅射ZnO层能有效抑制ZnO界面缺陷和改善界面接触性能,而采用分步溅射ZnO层与ILCNs联合修饰ZnO界面,这种联合修饰ZnO界面方案,更能增强ZnO层电子传输和提取能力,是提高聚合物太阳能电池效率更为有效方案。     

掺钌氢氧化钴复合材料在碱液中的电化学行为

应用化学共沉淀法制备掺钌氢氧化钴复合材料,X射线衍射(XRD)、扫描电子显微镜(SEM)显示非晶态RuO2颗粒分散在六方晶系Co(OH)2薄片的表面.循环伏安、恒流充放电测试表明,Co/Ru=8/1的复合材料在碱性电解液中具有优良的电容性能和较高的比容量.     

Influence of the High‐Frequency Capacitive Discharge Regimes on the Parameters of the Plasma in N2/CO2/He Gas Mixtures

The optical radiation spectra and the spatial structure of a planar highfrequency capacitive discharge in N₂/CO₂/He gas mixtures have been investigated depending on the excitation frequency, discharge current, pressure, and chemical composition of the mixture.     

横截面插入三根谐振线的矩形波导特性电纳的计算

本文针对矩形波导横截面上任意位置插入两根电感线和一根电容线的结构,通过变分的方法确定三根谐振线上电流的比例系数,从而得到其特性电纳的计算公式。本文的结果还可以用来计算一根电容带线、两根电感带线,三根电感带线或者两根对称电感带线和一根电容带线情况的特性电纳的计算。