阵列型微波黑体的发射率分析

在微波波段, 用于标定温度和辐射功率的发射率接近于1的标准发射率器件, 即微波频段的黑体, 结构形式一般为表面涂覆吸波材料的金属锥体阵列. 这种黑体器件常用于为微波辐射计提供参考亮温, 要求具有高发射率和均匀的温度分布. 对此类黑体器件的发射率评估主要基于基尔霍夫热平衡定律, 即通过评估反射率来确定发射率. 已报道的研究集中在黑体发射率随频率的变化趋势, 较少针对其随方向和极化状态的变化趋势. 本文针对此类周期型排布的黑体, 提出基于Floquet模式分析的反射率评估方法, 相比已报道的基于后向散射的评估方法, 具有更大的适用范围. 基于这种方法, 对某黑体的发射率随频率、角度和极化状态的变化规律进行了计算分析. 分析结果表明: 此黑体发射率在X到K_α波段内随频率提高而增大; 在发射率较低的低频处, 垂直极化与水平极化的发射率随俯仰角的变化趋势不同, 并且存在垂直极化发射率随俯仰角增大而明显降低的现象. 这些规律均与其物理上低频段内涂层对电磁波的衰减特性相符合.     

-60℃～80℃面源黑体辐射特性校准系统

分析面源黑体及其辐射特性校准在红外热像仪研制、航天红外遥感及民用领域等的需求背景。提出一种基于光谱辐亮度比对的－60℃－80℃面源黑体辐射特性校准装置，并详细地分析校准数学模型。     

大气层外核爆炸X－射线辐射场特性研究

Ｘ射线被认为是大气层外反导栏截武器的主要破坏因素。在航天器结构材料的辐射损伤计算中，需要核爆炸Ｘ射线辐射场的数学模式。从Ｐｌａｎｃｋ黑体谱出发，提出按温度梯度分层的归一化黑体谱组合模式，给出Ｘ－射线的释放能量及辐射脉冲，从而建立了大气层外核栏截Ｘ－射线辐射场特性的数学模式     

Chemical Reactivity on Gas‐Phase Metal Clusters Driven by Blackbody Infrared Radiation

We report the observation of chemical reactions in gas‐phase Rh_n(N₂O)_m⁺ complexes driven by absorption of blackbody radiation. The experiments are performed under collision‐free conditions in a Fourier transform ion cyclotron resonance mass spectrometer. Mid‐infrared absorption by the molecularly adsorbed N₂O moieties promotes a small fraction of the cluster distribution sufficiently to drive the N₂O decomposition reaction, leading to the production of cluster oxides and the release of molecular nitrogen. N₂O decomposition competes with molecular desorption and the branching ratios for the two processes show marked size effects, reflecting variations in the relative barriers. The rate of decay is shown to scale approximately linearly with the number of infrared chromophores. The experimental findings are interpreted in terms of calculated infrared absorption rates assuming a sudden‐death limit.     

室温黑体高精度测温电路的设计

介绍一种测量黑体的高精度测温电路。其测量范围为０—５０℃，测温精度为±０．１℃，最小分辨率为０．０２℃。     

黑体钳形腔

讨论黑体钳形腔的设计方法。给出黑体模拟数学式及适用腔体的几何参数。     

A Monte Carlo implementation to solve radiation heat transfer in non-uniform media with spectrally dependent properties

This paper presents the application of the Monte Carlo method to solve the radiative heat exchange in non-homogeneous, non-isothermal gases with spectrally dependent properties. Among others models, the absorption-line blackbody (ALB) distribution function, originally defined and derived for the spectral line-based weighted-sum-of-gray-gases (SLW) model, allows an immediate, simple implementation of the Monte Carlo method to account the spectral dependence of the radiative properties. This work shows how the Monte Carlo method can be combined to the ALB distribution function, and provides results for heat transfer in a mixture of water vapor, carbon dioxide and nitrogen that have satisfactory agreement with the SLW method and with line-by-line integration. Finally, the solution technique is employed to solve two examples aiming at demonstrating the effect of the absorbing species concentration on the thermal radiative exchanges. The method is of great interest for the computation of radiative transfer in combustion systems where the chemical species concentration and the temperature are not uniform.     

Amplitude-squared squeezing of the photon field in a Kerr-nonlinear blackbody

We find the photon field in a Kerr-nonlinear blackbody is an amplitude-squared squeezed state. The squeezing effect decreases with increasing temperature T. The amount of the amplitude-squared squeezing in a Kerr-nonlinear blackbody is much larger than the corresponding squeezing in normal blackbody, and the degree of amplitude-squared squeezing is much larger than the amplitude squeezing for the same range of parameters in a Kerr-nonlinear blackbody. The frequency ω_k and parameter γ also have important influences on the amplitude-squared squeezing in a Kerr-nonlinear blackbody.     

光纤瞬态高温传感器及动态测试系统

为了解决特殊环境下的瞬态高温测量, 设计了一种基于黑体辐射的光纤高温传感器及动态测试系统。根据辐射测温的基本原理, 结合光纤传感技术, 采用了“接触-非接触”测量方法和光纤光栅窄带滤波技术, 提高了测量精度, 减小了背景光的影响。由于瞬态温度随时间变化快, 动态误差大, 探索了一种利用大功率高频CO2激光器作为激励源, 用激光脉冲加热被校传感器。用测得的温度信号对被校传感器进行可溯源高温动态校准的新方案。实验结果表明, 系统测温范围为800～2000 ℃, 并具有精度高, 响应快, 抗电磁干扰, 性能稳定的特点, 解决了热电偶响应速度慢, 寿命短的缺陷, 为冶金、石油、化工、武器研制等领域的瞬态高温测量提供了一种新的测试手段。     

采用低温面源黑体实现红外系统宽动态范围定标

针对大口径地基红外辐射测量系统在辐射定标时存在定标时间长、成本高和设备机动性差等缺点,提出一种仅采用低温面源黑体实现红外系统宽动态范围定标的方法.首先对红外系统中的衰减片进行标校,测量其实际透过率并计算其辐射量;然后采用低温面源黑体在两个积分时间下分别进行辐射定标,根据定标结果解算系统响应率、杂散辐射和探测器自身偏置;结合标校获得的衰减片特性对低温定标结果进行外推,即可获得宽动态范围定标结果.为验证该定标方法有效性,分别采用该方法和通用的高温黑体加大口径平行光管定标法,对Φ600mm红外系统进行宽动态范围辐射定标实验.实验结果表明:本文方法的宽动态范围定标误差小于10.25%,能够满足该系统的辐射定标精度要求.该方法只需要一个低温黑体即可实现红外系统的外场宽动态范围辐射定标,操作简单、实时性强,具有一定的应用价值.