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1.
魏平田 《计测技术》1995,(6):7-11,22
从辐射测法中辐射率变化对温度的影响,讨论了多色辐射测量法的发展与应用实践,比较了不同处理方法的优缺点。  相似文献   

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Radiation     
《Vacuum》1974,24(6):278
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Radiation Weighting Factors and High Energy Radiation   总被引:1,自引:0,他引:1  
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Radiation Exposure and Radiation Risk in Civil Aircraft   总被引:4,自引:0,他引:4  
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原遵东 《计量学报》2014,35(5):434-439
用典型红外辐射温度计的辐射源尺寸效应的实验数据说明不同测量条件下的检定/校准结果的差异可能为其最大允许误差绝对值的数倍。提出具有明确测量条件的平面辐射源瞄准模型和以辐射源前置光阑的方式对于不同空腔黑体辐射源实现相同的等效平面源直径的方法,提出了对光阑的技术特性和放置距离要求,分析表明低温辐射源对光阑的冷却作用可能引起不可忽略的示值降低。采用等效平面源模型的实验结果表明以不同几何条件的空腔黑体辐射源可得到一致的检定结果。讨论了应用平面辐射源模型可能遇到的实际技术问题和解决的对策。  相似文献   

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复杂结构的声辐射解耦及其声辐射效率分析   总被引:5,自引:0,他引:5  
提出一种用边界元方法与声辐射理论求解复杂结构的声辐射模态与声辐射效率的理论方法。先将结构的声辐射功率表示为一个正定的厄米特二次型,运用广义特征值分解求解了复杂结构的声辐射模态,然后利用声辐射模态关于阻抗矩阵与均方速度耦合矩阵的正交性,求解了复杂结构的声辐射效率,最后用具有解析解的脉动球与辐射立方体验证了该方法的有效性。  相似文献   

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医院放射科空调系统的辐射防护问题   总被引:1,自引:0,他引:1  
唐志国 《制冷》2005,24(2):47-50
介绍了医院放射科产生射线的设备及射线的种类,介绍了空调风管穿越放射科房间墙壁时的处理措施,并着重介绍了包裹在风管外的辐射防护材料的屏蔽厚度的计算问题.  相似文献   

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Using spectral-analysis data and the statistical model of Goody, the emissivity and absorption coefficient of sulfur dioxide are calculated.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 30, No. 1, pp. 58–62, January, 1976.  相似文献   

10.
聚四氟乙烯的辐射交联   总被引:4,自引:0,他引:4  
概述了聚四氟乙烯辐射交联研究方面的最新成果。重点介绍了辐射交联工艺条件,加工过程安全性,交联后材料性能以及工业化应用前景。  相似文献   

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Tritium occurs from both natural and manufactured processes. In the environment, tritium can exist in the form of tritiated water (HTO) and in an organic form known as organically-bound tritium (OBT). Although, the concentrations of environmental OBT are relatively low, there is concern that current risk factors may underestimate the risk from OBT. Because tritium poses an internal hazard at cellular levels, microdosimetric techniques provide suitable tools for the study of radiation quality of tritium. In this study, microdosimetric simulations are performed for tritium uniformly distributed in a medium, and for tritium bound to biologically critical sites of dimensions from 10 nm to 2 microm. Results of local energy density are different for these two cases in microscopic regions. Based on the spatial distribution of energy deposition, dose mean lineal energies are calculated for tritium in forms of HTO and OBT. The dose mean lineal energies of OBT are about a factor of 1.7 higher than those of HTO in a wide range of target dimensions of biological interest. The results are consistent with radiobiological findings that OBT is about twice as effective as that of HTO.  相似文献   

13.
The National Metrology Institute of Spain (CEM) has designed, characterized, and set-up its new system to calibrate thermocouples and infrared radiation thermometers up to 1600 °C by comparison to radiation thermometry. This system is based on a MoSi2 three-zone furnace with a graphite blackbody comparator. Two interchangeable alumina tubes with different structures are used for thermocouples and radiation thermometer calibrations. The reference temperature of the calibration is determined by a standard radiation thermometer. Normally, this is used at CEM to disseminate the International Temperature Scale of 1990 (ITS-90) in the radiation range, and it refers to the Cu fixed point. Several noble metal thermocouples and infrared radiation thermometers with a central wavelength near 900 nm have been calibrated, and their uncertainty budgets have been obtained.  相似文献   

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为了检测出接近本底的低活度放射性物质,并且满足国家标准GB/T 24246-2009中对行人辐射监测系统的性能要求,本文设计了一种行人辐射监测系统,并对监测系统低放射性探测灵敏度测量原理进行了研究.本监测系统在本底稳定性满足要求的基础上,能够探测到接近本底的低活度放射性物质,为相关开发机构或安检部门开展类似问题研究提供...  相似文献   

17.
Absolute spectral radiometry is currently the only established primary thermometric method for the temperature range above 1300 K. Up to now, the ongoing improvements of high-temperature fixed points and their formal implementation into an improved temperature scale with the mise en pratique for the definition of the kelvin, rely solely on single-wavelength absolute radiometry traceable to the cryogenic radiometer. Two alternative primary thermometric methods, yielding comparable or possibly even smaller uncertainties, have been proposed in the literature. They use ratios of irradiances to determine the thermodynamic temperature traceable to blackbody radiation and synchrotron radiation. At PTB, a project has been established in cooperation with VNIIOFI to use, for the first time, all three methods simultaneously for the determination of the phase transition temperatures of high-temperature fixed points. For this, a dedicated four-wavelengths ratio filter radiometer was developed. With all three thermometric methods performed independently and in parallel, we aim to compare the potential and practical limitations of all three methods, disclose possibly undetected systematic effects of each method and thereby confirm or improve the previous measurements traceable to the cryogenic radiometer. This will give further and independent confidence in the thermodynamic temperature determination of the high-temperature fixed point’s phase transitions.  相似文献   

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《Journal of Modern Optics》2013,60(6):691-702
We study the general properties of the photon statistics of fluorescence radiation, emitted by a two-level atom in a strong laser field and a perturber bath. We investigate the deviation of the factorial moments from a Poisson distribution, and we show that for long counting times the lowest-order correction can be expressed entirely by the quantity Q, which represents the deviation of the variance from the average. We introduce and evaluate the quantities gn(t), which serve as a measure for the deviation of the higher-order statistics from Poissonian statistics. Subsequently we obtain explicit expressions for the average waiting time for the appearance of the n th photon, after an arbitrary initialization of the counting process. It turns out that the average time delay is again determined by Q. Hence this parameter can be measured in a photon-counting experiment, which involves only the observation of a single photon, rather than an (in principle) infinite number of photons.  相似文献   

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