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催化化学发光分析系统研究进展 总被引:1,自引:0,他引:1
催化化学发光是分子通过催化剂表面时被氧气氧化过程中产生的一种光辐射现象。在过去的三十几年里,催化化学发光技术发展迅速,特别是在传感器方面快速发展,成为一项新型分析检测技术,在公众安全、排放检测、环境保护等方面发挥了巨大的作用。基于催化发光技术设计的传感器具有检测限低、灵敏度高、快速、仪器简单易操作、易实现小型化,便携等优点,在无机小分子气体及易挥发有机物的分析检测中展现了其独特的优势。应用于催化发光的催化材料发展至今已达上千种,囊括了金属、金属氧化物,非金属氧化物、硫化物、硒化物、金属盐类、有机物、陶瓷玻璃类等各类材料;复合材料的应用丰富了催化材料的种类;纳米新材料的引入为其发展提供了新的契机;材料的形貌等也得以深入研究。催化发光新技术也不断发展,催化发光与其他技术(雾化、分离富集、等离子体等)联用的发展,静态催化发光技术、多级催化发光技术、循环催化发光技术等的开发应用进一步提高了催化法光分析系统的灵敏度与选择性,拓展了催化发光的应用范围。本文综述了近年来催化发光的催化材料、联用技术及其他新技术的发展,并对其发展趋势进行了展望。 相似文献
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采用掺镧锆锡钛酸铅反铁电陶瓷作为阴极材料,研究了脉冲电压激励下陶瓷的电子发射特性.当激励电压为800V、抽取电压为0V时,得到1.27A/cm2的发射电流密度;当抽取电压增加到4kV时,获得1700A/cm2的发射电流密度.分析了发射电流随抽取电压的变化关系,讨论了反铁电陶瓷强电子发射的内在机理.结果表明:掺镧锆锡钛酸铅反铁电陶瓷能够在较低的激励电压(400V)下实现电子发射,发射电流远大于按照Child-Langmuir定律计算出的电流,三接点附近局域反铁电—铁电相变产生初始电子发射,初始电子电离中性粒子形成等离子体,增强了电子发射.
关键词:
铁电阴极
反铁电体
电子发射 相似文献
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研究了丝阵Z箍缩等离子体内爆过程中单丝行为、物理参数匹配、X射线发射情况。根据丝阵Z箍缩等离子体动力学一维模型研制了相关的计算程序,对单丝的内爆过程进行了数值模拟,对丝阵箍缩匹配关系进行了计算,给出了丝阵初始半径、电流脉冲宽度和峰值电流的匹配关系,同时对丝阵内的最小丝间距、材料的选择等问题进行优化研究。 相似文献
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强激光激发下微微秒时间分辨光谱是最近几年发展起来的研究发光材料在极高密度激发下瞬态发光过程的新实验技术。从最近几年的研究工作看,它可以研究高密度激发下直接带半导体材料中的激子分子发光,激子和激子碰撞发光,高密度电子—空穴等离子体的发光等,还可用来区别激子发光和拉曼散射二次辐射等,由此可见这是一种很有前途的新技术。上述材料中的一些发光现象在低密度激发下是看不到的,当把激发密度提得很高时才表现出 相似文献
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常压下低温等离子体光辐射特性测量 总被引:1,自引:1,他引:0
采用常压空气辉光放电(APGD)技术在自行设计的电极板表面产生出一薄层低温等离子体,并利用光谱诊断光学系统对所产生的等离子体进行光辐射特性实验测量;实验获取了几种电极板在几个不同加载功率下的辐射光谱,并对光谱的辐射强度进行平均化处理分析。分析结果表明此沿面APGD的光辐射强度与加载功率之间存在线性增加的关系,且随电极板静态电容的增加而增强。该方法可以为控制APGD等离子体的产生量提供一种简便可行的途径。 相似文献
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“微环”等离子体辐射和粒子损失测量 总被引:1,自引:0,他引:1
本文报道了用高增益、快响应的钽酸锂热电探测器对“微环”托卡马克装置等离子体光辐射损失和粒子通量损失进行时空分辨测量的实验方法和结果。测量表明,在全部损失到壁上的功率中,中性粒子通量的贡献是主要的,光辐射损失只占小部分。对光辐射中不同波长的辐射功率进行了测量。 相似文献
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研究高功率微波作用下等离子体中的雪崩效应,对于研究等离子体防护技术具有重要意义.通过采用等离子体流体近似方法,建立等离子体中的波动方程、电子漂移-扩散方程和重物质传递方程,表征电磁波在等离子体中的传播以及等离子体内部带电粒子的变化情况,分析研究了高功率微波作用下雪崩效应的产生过程和变化规律.研究表明,入射电磁波功率决定了雪崩效应的产生;初始电子密度能够影响雪崩效应产生的时间;入射电磁波的激励作用初始表现为集聚效应,当激励能量积累到一定阈值时,雪崩效应才会产生;在雪崩效应产生过程中,等离子体内部电子密度的变化非常迅速并且比较复杂.雪崩效应产生后,等离子体内截止频率会远超过入射波频率,电磁波不能在等离子体中传播,从而起到防护高功率微波的效果. 相似文献
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从核爆炸光辐射特点出发, 结合我国中纬度地区大气特点,研究了(0.2~1.2)μm波段大气传输性能。通过实际测量数据分析可知,大气对(0.2~1.2)μm光辐射起主要作用的成分有水蒸气、二氧化碳和臭氧的分子吸收和散射以及气溶胶大粒子的散射。综合考虑这些因素,改进了水平路径传输上(0.2~1.2)μm光辐射大气传输经验方程。计算机仿真结果表明:该方程能体现我国中纬度地区光辐射的传输情况,对(0.4~0.8)μm可见光波段能很好地吻合。将(0.4~0.8)μm波段光辐射大气传输定量计算结果直接应用到基于可见光辐射探测的核爆炸探测子系统中,模拟核爆炸探测,实验结果表明:与传统大气传输计算软件的定性结果相比,该方法的测量精度有明显的提高。 相似文献
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A. K. Shuaibov V. I. Chygin L. L. Shimon I. V. Shevera P. P. Gorun R. O. Obukhovskii 《Technical Physics》2010,55(5):679-685
The results of studying the radiation due to argon, krypton, and xenon monochloride bands, as well as to the bands of chlorine molecules, from the plasma of a transverse Ar-Kr-Xe-Cl2 volume discharge are reported. The working mixture of a pulse radiation source is optimized with regard to its pressure and elemental composition and parameters of an excitation system. By numerically solving the Boltzmann kinetic equation for the electron energy distribution function, the transport characteristics of plasma electrons and discharge power specific losses are found for different values of the reduced electric field strength. The plasma parameters are simulated for the quaternary mixture, which is most appropriate for a multiwave UV-VUV source. Qualitative analysis is conducted for the most important electron processes in the multicomponent plasma that govern the joint formation of argon, krypton, and xenon monochlorides in the transverse discharge. 相似文献
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R. T. Kuznetsova V. A. Svetlichnyi T. N. Kopylova E. N. Tel’minov 《Optics and Spectroscopy》2000,89(2):236-242
Spectral luminescent properties of eight organic dyes are studied upon excitation by focused radiation from the XeCl* laser at the pump power up to 200 MW/cm2. The transmission of pump radiation by dyes is investigated as a function of the pump power. It is shown that variations in the energy, spectral, and temporal parameters of radiation of organic dyes upon high-power excitation are explained by the development of superluminescence (amplified spontaneous emission). 相似文献
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利用一维辐射流体力学程序MULTI数值模拟研究了功率为1014Wcm2、脉冲宽度为300ps、波长为0.44μm的强激光辐照平面Au靶时产生X射线的过程,给出了X射线转换效率和能谱分布.通过将靶物质划分为对所产生的X射线光学薄的转化区和光学厚的再发射区,得到了作为黑体辐射热源的最佳靶厚度,并给出了辐射加热靶所产生的等离子体的密度和温度的空间分布.
关键词:
辐射流体力学
激光等离子体
X射线转换
辐射热波 相似文献
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为优化交流等离子体显示器(AC PDP)的单元结构和驱动电压,采用光谱测量系统和交流等离子体显示器宏单元对电极结构参量、带有浮动电极的新型单元结构及维持电压脉冲参量对Ne-Xe混合气体放电辐射的红外光谱的影响进行了实验研究。结果表明,随着维持电极宽度增加,单元放电辐射的828 nm红外光谱的强度提高,而其辐射效率基本保持不变;随着维持电极间隙增大或在维持电极间加有适当宽度的浮动电极,红外辐射光谱的强度及其辐射效率均提高;提高维持电压脉冲频率或幅度,可增加红外辐射强度,但辐射效率降低。 相似文献
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Yin Xia Chuang Xue Chen-Guang Li Guang-Wei Meng Ying-Kui Zhao Jun Yan Bai-Wen Li 《理论物理通讯》2019,71(11):1388-1392
With the actual mean free path for radiation in air and a simplified nuclear device, a one-dimension simulation research on fireball phenomenon in a sea level atmosphere is carried out based on the multi-group radiation hydrodynamic codes (RDMG). It is shown that our theoretical calculations can describe the whole process of the fireball evolution for strong explosions from the early X-ray expansion stage to the shock wave propagation stage. The radius of the shock wave and the brightness of the fireball are in good agreement with the experimental results. The whole thermal radiation power curve of the fireball evolution for strong atmospheric explosion at sea level is plotted for the first time. The impact of radiation opacity of the nuclear device material on the early fireball phenomenon is also studied. It is found that trajectories of the radiation fronts and case shocks change with the opacity of equivalent device material. From our simulations, we find that only the early fireball depends on the details of the nuclear device, and after the formation of main shock, the evolution is determined by the properties of hot air for strong atmospheric explosion. 相似文献
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《Infrared physics》1992,33(1):47-51
Plasma luminescence has been measured in the visible range from 200 to 800 nm. The effect of collisions with sputtered copper ionic species at different argon gas pressures on the emission light intensity has been studied. The behaviour of well resolved lines at 210 and 657 nm as a function of gas pressure and microwave radiation power is measured. The transmission of He-Ne laser line (632.8 nm) through the induced plasma shows dependence on the microwave radiation power. There are observed transitions for the absorption of laser intensity for the filling gas pressures 0 and 5.3 torr at the radiation power of 175 W. 相似文献
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The radiation characteristics of a two-element array of equilateral triangular patch microstrip antenna on a ferrite substrate
are studied theoretically by considering the presence of bias magnetic field in the direction of propagation of electromagnetic
waves. It is found that the natural modes of propagation in the direction of magnetic field are left- and right-circularly
polarized waves and these modes have different propagation constants. In loss-less isotropic warm plasma, this array antenna
geometry excites both electromagnetic (EM) and electroacoustic plasma (P) waves in addition to a nonradiating surface wave.
In the absence of an external magnetic field, the EM- and P-waves can be decoupled into two independent modes, the electroacoustic
mode is longitudinal while the electromagnetic mode is transverse. The far-zone EM-mode and P-mode radiation fields are derived
using vector wave function techniques and pattern multiplication approaches. The results are obtained in both plasma medium
and free space. Some important antenna parameters such as radiation conductance, directivity and quality factor are plotted
for different values of plasma-to-source frequency. 相似文献