5种固体径迹氡探测器某些性能的比较以及火花计数器的改进

对5种固体径迹氡探测器的相对误差、探测下限和探测效率等性能作比较测试后,推荐出一种有推广价值的探测器。改进了火花计数器的成形电路,并对计数器中心电极尺寸、重物等予以研究。改进后的火花计数器的径迹密度测量上限经“重孔”校正后,对直径为21、16和11mm的中心电极分别为4000、4600和5000/cm~2。     

驻极体测氡法及其应用

驻极体收集积分测氡法利用驻极体产生的静电场收集~(218)Po~+离子,显著地提高了测氡灵敏度。文章介绍了方法在秦山核电站、湖南省环境监测中心站和一些铀矿山应用的情况及质量保证体系。     

Meteorological Database for the United States

Abstract A meteorological database for the 48 contiguous states of the United States has been developed for use in indoor air pollution predictive models. The database contains predicted typical monthly meteorological statistics at the county level derived from hourly meteorological data from 208 (234 for precipitation) geographically distinct monitoring stations. Interpolation and extrapolation techniques were used to predict statistics for counties not containing a meteorological monitoring site. The LBNL database includes statistics for meteorological variables including dry-bulb temperature, dew-point temperature, barometric pressure, wind speed, wind direction, hours of precipitation, precipitation, and derived infiltration degree-days. The database consists of individual files of derived statistics for each weather variable and is potentially useful for indoor radon modeling as well as for other purposes. Each file contains data values for all 12 months and an aggregation of the 12 months up to a yearly statistic for all county centroids. A test was conducted to assess the quality of interpolated values. Examples showing the use of the database for mapping infiltration degree-days and an application of the database to a statistical correlation analysis attempting to find meteorological factors influencing indoor radon levels in the United States are discussed.     

有源扩散方程的一种解和“双滤纸法”测氢的换算公式

文章从流速场中级联衰变下气载核素的扩散规律出发,提出了强吸附性壁圆管内氡子体扩散方程的完整定解问题,求出了等速分布廓线时的方程的精密解,弥补了C.W.Tan这部分工作的不足。引进了新的物理量m(μ),导出了等速分布条件下m(μ)与F(μ)的互换关系式。从测量氡子体的α计数出发,通过放射性平衡比m(μ)给出了“双滤膜法”测氡的换算公式。由J·W·Thomas的精密实验数据,取镭-A扩散系数D=0.07cm~2·s~(-1)时,理论与实验十分吻合。     

香港地区土壤和建筑材料中天然放射性水平及天然辐射所致居民剂量估算

本文报道了香港地区土壤、常用建材及路基体中~(238)U、~(226)Ra、~(232)Th 和~(40)K 含量的测量结果,由此估算了空气γ吸收剂量率和室内氡浓度,并且与初步实测值进行了比较。最后估算出天然本底辐射所致香港居民人均年有效剂量当量为3.24 mSv。     

气球法测氡比对实验

本文详细介绍了一二次气球法测氡比对实验。１９８６年比对发现气球法灵敏度低，比对结果普遍偏高等问题。１９８８年比对针对上述问题采取了相应的措施，取得了较为满意的结果。在环境水平氡浓度下，参加者之间符合良好，并基本上消除了经典的闪烁法之间的方法误差。此外，还讨论了一些具体问题，如滤膜过滤效率、穿过滤膜子体的影响等。     

非恒定浓度氡刻度室及其在测氡刻度中的应用

非恒定浓度氡刻度室是一种用于相对测量的刻度装置。文章介绍了装置的基本原理和方法。刻度实验指出,刻度系数相对标准差为±10%。氡刻度室还具有经济、方便的特点。     

Characterization of Radon Decay Products in a Domestic Environment

Field measurements of the concentration and activity size distribution of radon decay products were conducted in a one-story house located in the Princeton, NJ area. Radon concentration and particle number concentration were also measured. The concentration and activity-weighted size distribution of radon decay products were determined using a microcomputer-controlled, semi-continuous screen diffusion battery system with 6 parallel sampler/detector units. A condensation nuclei counter was used for the measurements of indoor panicle number concentration. Several measurements were made in the living room as well as more than one hundred measurements in the master bedroom of the Princeton house. Aerosols were generated from taking a shower, burning a candle, smoldering a cigarette, vacuuming, and cooking. Therefore, the influence of various indoor panicle sources on the behavior of radon decay products was investigated. With panicles generated from typical household activities, Potential Alpha Energy Concentration (PAEC) increases and the unattached fraction decreases. Larger panicles generated from cigarette smoke and cooking dramatically shifted most of the radon decay products into the attached mode (15-500 nm). With regard to the higher attachment rate, the size distributions of radon decay products remained stable for long periods of time after particle generation. On the other hand, aerosols produced from candle burning and vacuuming were much smaller, with an average attachment diameter of 15 nm. These panicles did decrease the unattached fraction, especially during the aerosol generation period. However, the size distributions of radon decay products returned to the background condition within ISO minutes after the end of particle generation. In these cases, the panicles had a higher deposition rate and a lower attachment rate. The dose of alpha radiation per unit radon concentration resulting from each of these aerosol conditions was calculated using the measured activity size distributions and the most recent James dosimetric model. These doses to basal cells at a breathing rate of 0.45 m³ hr¹ ranged from 3 to 14 μGy Bq^?1 hr while the dose to secretory cells at a breathing rate of 1.5 m³ hr¹ ranged from 13 to 77 μGy Bq^?1 hr for the various aerosol conditions.     

吸入氡子体气溶胶粒子在呼吸道内的沉着分布

本文使用气溶胶粒子通过圆柱管的沉着机制——布朗扩散、重力沉降及惯性碰撞沉着理论和怀希尔(Weibel)肺模型,计算出吸入氡子体气溶胶粒子在各支气管段的沉着几率。根据沉着几率和氡子体放射性在气溶胶粒子上的分配比,从而获得吸入氡子体的沉着量。用计算结果与流行病学资料进行比较,氡子体沉着量多的支气管亦是肺癌发病率高的位置。     

吸入短寿命氡子体家兔肺剂量随日龄的变化

本文介绍吸入短寿命氡子体的家兔肺组织吸收剂量随日龄的变化。实验结果指出,新生家兔肺组织剂量相对较低,而后剂量随日龄的增大而增高,20—40天幼兔的肺组织剂量达最大值,然后又下降。