Alternating current（AC） conductivity and dielectric properties of thermally evaporated Au/Pt OEP/Au thin films are investigated each as a function of temperature（303 K–473 K） and frequency（50 Hz–5 MHz）.The fre...Alternating current（AC） conductivity and dielectric properties of thermally evaporated Au/Pt OEP/Au thin films are investigated each as a function of temperature（303 K–473 K） and frequency（50 Hz–5 MHz）.The frequency dependence of AC conductivity follows the Jonscher universal dynamic law.The AC-activation energies are determined at different frequencies.It is found that the correlated barrier hopping（CBH） model is the dominant conduction mechanism.The variation of the frequency exponent s with temperature is analyzed in terms of the CBH model.Coulombic barrier height Wm,hopping distance Rω,and the density of localized states N（EF） are valued at different frequencies.Dielectric constant ε1（ω,T） and dielectric loss ε2（ω,T） are discussed in terms of the dielectric polarization process.The dielectric modulus shows the non-Debye relaxation in the material.The extracted relaxation time by using the imaginary part of modulus（M’’）is found to follow the Arrhenius law.展开更多
基于荧光淬灭原理的光纤氧传感器一直是许多研究工作的重点。介绍了一种制作简单、成本低的光纤氧传感器制造方法。该方法基于荧光淬灭原理,在光纤末端涂覆荧光材料铂八乙基卟啉(PtOEP)实现的。传感器中荧光材料被395nm的紫光激发,并由...基于荧光淬灭原理的光纤氧传感器一直是许多研究工作的重点。介绍了一种制作简单、成本低的光纤氧传感器制造方法。该方法基于荧光淬灭原理,在光纤末端涂覆荧光材料铂八乙基卟啉(PtOEP)实现的。传感器中荧光材料被395nm的紫光激发,并由Y形光纤引导,使用广州犀谱光电USB2000+光谱仪记录荧光的发光强度时序图。最后得到的PtOEP的( I 0/ I 100 )-1的值为0.78,即光纤氧传感器的灵敏度为0.78,而且,斯特恩-沃尔默(Stern-Volmer)图显示出很好的线性特性。从氧气到空气环境的响应时间为24 s,从空气环境到氧气的响应时间是5 s。结果表明,基于荧光淬灭原理的光纤氧传感器具有较高的灵敏度和更快的响应时间。展开更多
文摘Alternating current（AC） conductivity and dielectric properties of thermally evaporated Au/Pt OEP/Au thin films are investigated each as a function of temperature（303 K–473 K） and frequency（50 Hz–5 MHz）.The frequency dependence of AC conductivity follows the Jonscher universal dynamic law.The AC-activation energies are determined at different frequencies.It is found that the correlated barrier hopping（CBH） model is the dominant conduction mechanism.The variation of the frequency exponent s with temperature is analyzed in terms of the CBH model.Coulombic barrier height Wm,hopping distance Rω,and the density of localized states N（EF） are valued at different frequencies.Dielectric constant ε1（ω,T） and dielectric loss ε2（ω,T） are discussed in terms of the dielectric polarization process.The dielectric modulus shows the non-Debye relaxation in the material.The extracted relaxation time by using the imaginary part of modulus（M’’）is found to follow the Arrhenius law.
文摘基于荧光淬灭原理的光纤氧传感器一直是许多研究工作的重点。介绍了一种制作简单、成本低的光纤氧传感器制造方法。该方法基于荧光淬灭原理,在光纤末端涂覆荧光材料铂八乙基卟啉(PtOEP)实现的。传感器中荧光材料被395nm的紫光激发,并由Y形光纤引导,使用广州犀谱光电USB2000+光谱仪记录荧光的发光强度时序图。最后得到的PtOEP的( I 0/ I 100 )-1的值为0.78,即光纤氧传感器的灵敏度为0.78,而且,斯特恩-沃尔默(Stern-Volmer)图显示出很好的线性特性。从氧气到空气环境的响应时间为24 s,从空气环境到氧气的响应时间是5 s。结果表明,基于荧光淬灭原理的光纤氧传感器具有较高的灵敏度和更快的响应时间。
