Theoretical analysis for transmission of Gaussian and sine time irradiance of electromagnetic beam in collisional dusty plasmas

A theoretical model of propagation of Gaussian and Sine time irradiance of an electromagnetic beam in collisional dusty plasma has been done in the present analysis. It contains equilibrium of dust charge, particle density, and energy of plasma ingredients having charge neutrality. Ionization of neutral particles, recombination of free electrons with ions, adsorption and emission of electrons from dust grain surface, and binary collisions between plasma components are also considered in this treatment. Time varying behaviour of modified electron temperature and collision frequency has been illustrated numerically as a function of dust densities. Also, the comparative analyses of variation of beam waist parameter with the dimensionless length of transmission for both the Gaussian and Sine time irradiance are involved in this model as a function of distinguishable time width, collision frequencies, and dust densities under the condition that the size of dust nebulous is greater than the electrons mean free path for the adsorption on the dust grain surface. The observed results are significant for the applications in industry and astrophysics.     

Progress of laser ionization mass spectrometry for elemental analysis — A review of the past decade

Mass spectrometry using a laser ionization source has played a significant role in elemental analysis. Three types of techniques are widely used: high irradiance laser ionization mass spectrometry is capable of rapid determination of elements in solids; single particle mass spectrometry is a powerful tool for single particle characterization; and resonance ionization mass spectrometry is applied for isotope ratio measurements with high sensitivity and selectivity. In this review, the main features of the laser ablation process and plasma characterization by mass spectrometry are summarized. Applications of these three techniques for elemental analysis are discussed.     

用于测量太阳总辐射的空间辐射计

简述了在不同航天任务上测量太阳总辐射的各种辐射计,以及这些辐射计的结构、仪器特性、原理和运行等。这些空间辐射计大多数采用电标定的原理,以腔体探测器作为感知太阳总辐射的传感器。讨论了空间辐射计寻日方式对太阳总辐射测量精度的影响。最后,结合以往宇航任务中太阳总辐射测量的历史和经验,简述了高精度测量太阳总辐射空间辐射计的发展趋势。     

溯源于低温绝对辐射计的太阳光谱辐照度仪定标方法研究

为了提高太阳直射光谱辐照度的观测精度,对使用棱镜分光的太阳光谱辐照度仪,在可见-近红外波段开展了基于标准探测器的辐射定标方法研究。建立了可调谐激光器-积分球的辐照度定标装置,以溯源于低温绝对辐射计的标准辐照度探测器作为传递基准,通过替代法得到照度仪在可见-近红外10个波段的绝对光谱辐照度响应度,分析得到的合成定标不确定度优于0.95%。与溯源于中国计量院金点黑体的标准灯定标法进行了比对实验,两者的偏差在4.67%的范围内,证明了此辐射标准传递方法的合理性。     

可见-近红外波段太阳光谱辐照度仪的辐射定标方法研究

为了满足可见-近红外波段太阳光谱的高精度观测需求,对使用细分光谱技术进行太阳直射辐射观测的新型太阳光谱辐照度仪,开展了辐射定标方法的研究。使用光谱辐照度标准灯在400 nm～1 050 nm光谱范围内对仪器进行相对定标,对满足比尔-朗伯定理的波段采用Langley法进行绝对定标,在整个光谱范围内将辐射基准溯源到大气层顶的太阳光谱辐照度。在甘肃敦煌和安徽合肥两地进行了室外比对实验,仪器观测结果和MODTRAN4.0模型的理论模拟结果一致,和CE318的4个气溶胶观测通道的结果偏差在5%以内,验证了该定标方法的合理性。     

城市路径下激光光强起伏特性测量及链路余量估算

在城市环境下进行了3.5 km的激光大气传输实验。实验中对光强起伏和到达角起伏进行了同步测量,分析了接收光强起伏的统计特性以及传输路径上大气折射率结构常数的特性。基于实验结果,对自由空间光通信中不同闪烁指数下的衰落冗余以及不同探测阈值下的衰落概率进行了估算,从而为空间光通信系统的设计提供可靠的实验基础。     

Spectroradiometry Applied to Dental Composite Light Curing

Abstract: In the literature the irradiance of light-curing units (LCUs) is usually measured and expressed in watt per square centimeter (Wcm^?2) or as spectral irradiance with arbitrary units. However, neither situation measures how the broadband really interacts with the substrate. For the correct dosimetry of such sources, it is necessary to evaluate the spectral distribution of their irradiance, also called spectral irradiance, which has units of Wcm^?2nm^?1. Here, the theory of optical dosimetry with respect to dental light-cure composite resins is revised; moreover, experimental determination of the optical dosimetry of composite resins cured with light-emitting diode (LED) sources is reported, including all of the substrates participating in the curing processes, especially the adhesive agent, as well as adjacent tissues like the enamel and dentine. A review of the literature showed that a casual use of different radiometric quantities and units is observed. This encompasses many types of mistakes and gives rise to dubious interpretation of the published results. We strongly recommend that interdisciplinary coworkers solve this kind of problem before publication and provide additional reliability and accordance with internationally assigned radiometric quantities and units as published by the Bureau International des Poids et Mesures and the International Union of Pure and Applied Chemistry (IUPAC).     

积分球的光功率波形变换理论

分析说明了积分存在一次反射短时平均等照度性质，提出了积分球的几个概念：平均反射程λ、平均反射时间μ、平均反射率ρ^-、平均出射程η、平均出射时间τ（等于积分球的时间常数）。用分析方法推导了积分球时间常数的一般表达式、积分球对δ函数形式的功率波形的变换表达式、积分球对任意光功率波形的变换表达及其反变换表达式。     

Numerical procedures and their practical application in PV modules’ analyses. Part II: Useful fractions and APE

The article regards aspects of PV modules tested with the use of natural sunlight. The analysis of spectral structure of solar energy resources in southern Poland, carried out on the basis of meteorological data originating from SolarLab PW Wrocław and AGH Kraków, Poland [1] was used in the article. It is a continuation of the article: Analysis of solar energy resources in southern Poland for photovoltaic applications [1], describing the method to determine spectral parameters of average photon energy (APE) and useful fraction (UF) with the use of a solar radiation spectrum simulator. This article, however, includes an experimental presentation of their impact on PV conversion of modules with different absorbers. Theory and practice of the measurements were described with the use of spectral parameters such as: UF, APE. Their influence on the efficiency of modules’ photovoltaic conversion with various spectral characteristics of absorbers was presented. The most recent methods described, which characterise the structure of solar energy resources such as annual distributions of APE and UF, have not been commonly used yet in Poland and other countries, even though they most precisely define adjustment of the spectral factor to the selected PV module.Practical application of UF, in detection of absorber type used in the tested PV module/cell is demonstrated in the final part of the article.     

距离选通成像系统分辨力模拟测试装置的设计

距离选通成像系统采用的是脉冲激光主动照明与ICCD选通技术相结合的方法。为了在室内模拟测试在一定大气条件下距离选通成像系统的分辨力,设计了一套模拟测试装置。以辐射传输理论为基础,建立了大气距离选通成像系统后向散射光和信号光的模型。该模型给出了后向散射光和信号光在光电阴极面上照度随时间的变化规律。采用两个模拟光源,分别模拟了信号光和后向散射光。采用阴极面等效辐射照度法,给出了模拟光源功率的方法。以S 20光电阴极的像增强器与CCD的耦合为例,计算了模拟光源的功率。