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对庐江地震台化学实验室内不同季节空气中氡和汞含量进行测量、分析,得出影响观测室内空气中氡值的主要因素为,标定仪器和空气流通情况,并与国家环境控制标准做对比,得出庐江地震台化学实验室内空气质量符合国家环境控制标准要求。同时,对如何降低室内空气中氡、汞的含量,提出相应的预防措施。 相似文献
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根据氡观测仪的氡室校准和氡气固体源校准两种校准方式的实验结果, 讨论了使用标准仪器校准氡观测仪器的可靠性问题。 用国际公认的计量传递仪器AlphaGUARD P2000Pro或AlphaGUARD P2000F测氡仪作为氡气溯源仪器, 对九江地震台FD-125氡钍分析器的三个闪烁室进行了氡室校准、 氡气固体源校准和仪器校准三种方法实验, 得到标准仪器校准、 氡气固体源校准得出K值相对氡室校准结果偏差均小于6%, 结果表明, 三种方法的校准结果均符合目前氡观测计量溯源技术要求, 能达到与国家氡计量刻度相统一目的。 相似文献
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利用HD-6型多功能自控氡室, 配合国际标准计量仪器AlphaGUARD PQ2000Pro测氡仪, 分别采用循环采样和负压采样两种方式, 对FD-125氡钍分析器的3个闪烁室进行校准实验, 计算3个闪烁室K值和相对固有误差。 结果表明: 循环采样方式得到的闪烁室K值比负压采样方式小, 负压采样方式得到的K值偏大, 已经接近《地震水文地球化学观测技术规范》要求的闪烁室K值的极限。 循环采样得到的闪烁室相对固有误差≤5%, 达到了《地震水文地球化学观测技术规范》的要求, 而负压采样方式得到的闪烁室相对固有误差>5%, 未达到《地震水文地球化学观测技术规范》的要求; 因此, 循环采样方式更适合地震监测闪烁室法测氡仪的氡室校准。 相似文献
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Radon-thoron monitoring in Tatun volcanic areas of northern Taiwan using LR-115 alpha track detector technique: Pre-calibration and installation 总被引:1,自引:0,他引:1
Arvind Kumar Vivek Walia Tsanyao Frank Yang Hsiao-Hsien Chang Shih-Jung Lin Karumpil Philips Eappen Baldev Raj Arora 《Acta Geophysica》2013,61(4):958-976
In the present study, experiments have been carried out to calibrate LR-115 alpha detector films in bare and cup-mode exposure for the measurement of radon and thoron concentrations in soil gas. Results showed non-uniformity in track formation on the films in bare-mode exposure. However, in cup-mode exposure the non-uniformity was reduced to a greater extent. The calibration factors obtained for radon in bare- and cup-mode exposures are 0.049 and 0.034 tr. cm?2 per Bq m?3 d, respectively. An attempt has been made to calibrate the radon-thoron discriminative cup with LR-115 films for simultaneous measurements of radon and thoron. This paper also presents the preliminary results of radonthoron monitoring in Tatun volcanic areas of northern Taiwan for the first time using radon-thoron discriminators with LR-115 films. The results show that the safe temperature to install the LR-115 films in volcanic areas is ≤ 65°C and thoron concentration in the study area is low. 相似文献
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Luis S. Quindos Poncela Carlos Sainz Fernandez Ismael Fuente Merino Jose L. Gutierrez Villanueva Alberto Gonzalez Diez 《Acta Geophysica》2013,61(4):848-858
Radon can be used as a naturally occurring tracer for environmental processes. By means of grab-sampling or continuous monitoring of radon concentration, it is possible to assess several types of dynamic phenomena in air and water. We present a review of the use of radon and its progeny at the University of Cantabria. Radon can be an atmospheric dynamics indicator related with air mass interchange near land-sea discontinuities as well as for the study of vertical variations of air parameters (average values of different types of stability: 131–580 Bq m?3). Concerning indoor gas, we present some results obtained at Altamira Cave (Spain): from 222 to 6549 Bq m?3 (Hall) and from 999 to 6697 Bq m?3 (Paintings Room). Finally, variations of radon concentration in soil (0.3 to 9.1 kBq m?3) and underground water (values up to 500 Bq l?1) provide relevant information about different geophysical phenomena. 相似文献
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测氡仪对比观测研究是探索仪器运行规律和提供可靠地震研究数据的支撑。文章基于使用AlphaGUARD P2000测氡仪作为无源标定仪器对DDL-2测氡仪进行溶解氡的校准实验,开展DDL-2测氡仪氡浓度响应研究以及DDL-2测氡仪和FD-105K测氡仪对比观测研究。结果表明:(1)校准K值的偏差值都在4.827 6%以内,满足目前地震监测观测技术要求和仪器标定要求;(2)DDL-2测氡仪可描述动态的水氡浓度,使用Origin 2018数据分析软件对氡浓度绘制拟合曲线,为氡值变化过程提供数学模型,鼓泡过程中水氡浓度经历迅速上升期、平缓期和稳定期,稳定后氡浓度变化幅度约为5.0 Bq/L,并且变化形态不尽相同;(3)使用Origin 2018对比分析数据,发现DDL-2测氡仪与AlphaGUARD P2000测氡仪较FD-105K测氡仪氡浓度日变化响应更灵敏且氡测值曲线吻合度更高。 相似文献
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H. A. Wollenberg A. R. Smith D. F. Mosier S. Flexser M. Clark 《Pure and Applied Geophysics》1984,122(2-4):327-339
In the Long Valley caldera, where seismicity has continued essentially uninterrupted since mid-1980 and uplift is documented, samples of water from hot, warm, and cold springs have been collected since September, 1982, and their222Rn concentrations analyzed. Concurrently, rocks encompassing the hydrologic systems feeding the springs were analyzed for their radioelement contents, because their uranium is the ultimate source of the222Rn in the water.The222Rn concentration in the springs varies inversely with their temperature and specific conductance. High concentrations (1500 to 2500 picocuries per liter) occur in dilute cold springs on the margins of the caldera, while low contents (12 to 25 pCi/l) occur in hot to boiling springs. Springwater radon concentrations also correlate slightly with the uranium content of the encompassing rocks.A continuous monitoring system was installed in August, 1983, at a spring issuing from basalt, to provide hourly records of radon concentration. A gamma detector is submerged in a natural pool, and we have observed that the radioactivity measured in this manner is due almost entirely to the222Rn concentration of the water. Initial operation shows diurnal and semidiurnal variations in the222Rn concentration of the springwater that are ascribed to earth tides, suggesting that those variations are responding to small changes in stress in the rocks encompassing the hydrologic system. 相似文献
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利用国际刻度参考装置AlphaGUARD测氡仪及水氡测量组件, 使用水中溶解氡(或豁免级氡气源), 开展代替目前氡气固体源校准方法实验。 对FD-125测氡仪标配的3个闪烁室(1#、 3#及5#)分别使用水中溶解氡和氡气固体源进行校准实验, 3个闪烁室的校准K值相对误差分别为5.06%, 1.92%及2.76%, 可以达到目前地震监测氡观测技术要求。 实验结果表明, 水中溶解氡代替氡气固体源校准, 可以解决目前氡气固体源校准中存在的运输困难、 维修技术要求高等问题, 是今后氡观测仪器校准技术的发展趋势。 相似文献
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Constantin Cosma Botond Papp Mircea Moldovan Victor Cosma Ciprian Cindea Liviu Suciu Adelina Apostu 《Acta Geophysica》2010,58(5):947-956
Soil radon gas and/or its exhalation rate are used as indicators for some applications, such as uranium exploration, indoor
radon concentration, seismic activity, location of subsurface faults, etc., and also in the studies where the main interest
is the field verification of radon transport models. This work proposes a versatile method for the soil radon sampling using
a special manner of pumping. The soil gas is passed through a column of charcoal by using passive pumping. A plastic bottle
filled with water is coupled to an activated charcoal column and the flow of water through an adjustable hole made at the
bottom of bottle assures a controlled gas flow from the soil. The results obtained for the activity of activated charcoal
are in the range of 20–40 kBq/m3, for a depth of approximately 0.8 m. The results obtained by this method were confirmed by simultaneous measurements using
LUK 3C device for soil radon measurements. Possible applications for the estimation of radon soil potential are discussed. 相似文献
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2008年8月福建省地震局水化学中心实验站对新购置的水氡仪器进行标定,标定结果出现异常:全部闪烁室K值超出《地震水文地球化学观测技术规范》所要求的取值范围,但每个闪烁室多次标定的K值的相对偏差基本小于5%,说明虽然K值超出要求,但是固体氡气源装置上标称氡射气剂量分配值是稳定的。造成标定结果异常的可能原因主要有,标定过程出现漏气,新仪器选择的各项指标有误,固体氡气源故障。更换干燥剂、橡皮管,检查每一个接口,以及闪烁室的密封性能和真空泵的抽真空性能,重新检查仪器状态均已正常后,用现用的两套仪器进行标定,以检验是否因新仪器选择的各项指标有误造成标定结果异常。两次标定结果类似,分析认为,可能是固体氡气源故障,虽然在这次标定中,固体氡气源装置上标称氡射气剂量分配值是稳定的,但可能其含量较以前发生了变化。 相似文献
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聊古一井数字化氡与模拟水氡观测资料的对比评价 总被引:9,自引:0,他引:9
数字化氡在聊古一井投入观测已近4年, 与模拟水氡观测相比, 具有采样率高, 数字传输、保存和资料处理快捷方便, 人为观测误差少的优点, 从而使氡的信息量大大增加, 为捕捉地震短临异常信息提供了有利条件。对数字化氡与模拟水氡同期观测资料的对比分析结果表明, 二者的变化趋势、方差及均值变化均不一致, 数字化氡与模拟水氡观测的物理含义不同,是一种新的测项, 尚不能完全替代原有的模拟水氡观测; 数字化氡在反映地震短临异常方面优于模拟水氡; 气水分离装置(脱气装置)是实现氡数字化观测的重要基础环节, 对于获取真实可靠的观测结果具有重要作用。 相似文献
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Implementation of an automatic calibration procedure for HYDROTEL based on prior OAT sensitivity and complementary identifiability analysis 下载免费PDF全文
Médard Bouda Alain N. Rousseau Silvio J. Gumiere Patrick Gagnon Brou Konan Roger Moussa 《水文研究》2014,28(12):3947-3961
Efficiency of hydrological models mostly depends on the quality of the calibration performed prior to use. In this paper, an automatic calibration framework for the distributed hydrological model HYDROTEL is proposed. The calibration procedure was performed for three watersheds characterized with different hydroclimatological conditions: the Sassandra located in Ivory Coast, Africa, and the Montmorency and Beaurivage watersheds located in Quebec (Canada). Results of one‐a‐time (OAT) sensitivity analysis showed that the order of the most sensitive parameters differs for each watershed. Thus, the sensitivity depends on the hydroclimatic and physiographic characteristics of the watersheds. Co‐linearity indices showed that all model parameters were identifiable, that is, none of the studied parameters could be explained by a combination of the other parameters. Following these findings, an automatic calibration was run. Results indicated there was good agreement between simulated and measured streamflows at the outlet of each watershed; Nash–Sutcliffe efficiency (NSE) ranging between 0.77 and 0.92 and R2 ranging from 0.87 to 0.97. When comparing NSE and R2 values obtained using a process‐oriented, multiple‐objective, manual calibration strategy, a slight increase in model efficiency was reached with the automatic calibration procedure (4.15% for NSE and 2.95% for R2) improving predictions of peak flows for the Montmorency and Beaurivage watersheds (temperate climate conditions) and flows beyond the rainfall season in the Sassandra watershed. The proposed automatic calibration procedure introduced in this paper may be applied to other distributed hydrological model. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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对测氡仪器进行定期校准是保证测量结果准确性和可靠性的关键。基于用国际公认的计量传递仪器AlphaGUARD P2000F作为氡气溯源仪器及其自带水氡测量组件对三套DDL-1型电离法测氡仪使用水中溶解氡进行校准实验。实验结果和用固体氡源校准三套仪器的结果与仪器出厂校准结果进行对比,两种校准方法的K值相对误差均小于5%,达到目前地震监测氡观测技术要求。实验结果表明,水中溶解氡代替固体氡气源校准,可以解决目前固体氡源校准中存在的运输困难、维修技术要求高、国家环保部门监管严格等问题,为地震氡观测仪器校准技术找到了一种新的途径。 相似文献
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A laboratory instrument was developed to investigate the electrical properties of rock samples with respect to changes of frequency, temperature and pressure. The instrument can be used to obtain general trends and typical values for geological media. It should be of particular interest in geothermal studies and research in the geophysical properties of rocks. The design intervals for quantities under investigation were 20–300°C, 105-4 × 107 Pa and 5 × 10?4-103 Hz. Certain limitations exist on the simultaneous use of the highest values of temperature and pressure. The main features of the instrument are: analog electrical outputs recorded by an x-y recorder or observed on a scope with an attached camera (according to the frequency range); pressures produced by an oil hydraulic system in order to ensure electrical insulation of the sample; temperatures obtained by placing the pressure vessel into a thermostatically controlled room. Thus the monitoring instrumentation is directly accessible during the experiment. Information is also given about calibration procedures and examples of rock sample data are given. 相似文献
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A. A. Spivak S. A. Kozhukhov M. V. Sukhorukov V. A. Kharlamov 《Izvestiya Physics of the Solid Earth》2009,45(2):118-133
The results of measurements of the volumetric activity of subsurface radon Rare given for several sections of the Earth’s crust located within the central part of the East European Platform. The influence of tectonic structures on the spatial zonality of radon emanation and the intensity of its temporal variations is shown. The temporal variations in radon emanation are characterized by periodicity with periods of approximately a day, as well as of 4, 14, and 29 days, and, as correlation analysis shows, they are determined by the cyclic recurrence of tidal deformations and by cyclonic processes in the atmosphere. The high correlation of the mean values of the volumetric activity of subsurface radon with the value of atmospheric pressure is established. The dependence of the volumetric activity of subsurface radon and its temporal variations on the depth within the range of depths 0.8–11.5 m is determined. As a result of laboratory experiments, the nonlinear nature of the dependence of radon emanation on the frequency of vibration action is established. For granites, the intensity of radon emanation is maximal at frequencies of 16 and 32 Hz. The results of complex measurements of the microseismic background and the volumetric activity of subsurface radon carried out in the region of the Nelidovo-Ryazan tectonic structure demonstrate the high correlation between the volumetric activity of subsurface radon and the relative amplitude of the quasi-monochromatic component of the microseismic background with a peak frequency of 16.5 Hz. 相似文献
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The concentrations of222Rn and226Ra in the water column and in the sediments of Santa Barbara and San Nicolas Basins have been measured semi-annually over the last four years. Approximately one-third of excess radon profiles obtained in the water column in these basins can be adequately fit with a one-dimensional eddy diffusion-decay model. Exponential profiles in the center of San Nicolas Basin yield a vertical eddy diffusivity of 26±16 cm2/s and 3.4±1.0 cm2/s for Santa Barbara Basin. The application of a two-dimensional eddy diffusion-decay model to profiles obtained in the center and on the margins of San Nicolas Basin produces a better fit than is found using a one-dimensional vertical eddy diffusivity. The two-dimensional model for San Nicolas Basin predicts a vertical eddy diffusivity of 17 cm2/s and a horizontal eddy diffusivity of 105 cm2/s. These values are in reasonable agreement with those predicted from the vertical buoyancy gradient and the horizontal length scale.The vertically integrated radon excess (standing crop) in the water column of Santa Barbara Basin averages 53±23 atoms/m2 s. This is in good agreement with the flux across the sediment-water interface of 60±15 atoms/m2 s, calculated by measuring radon emanation in the sediments as a function of depth and applying a molecular diffusion-reaction model. Hence, one-dimensional molecular diffusion accurately predicts the flux of radon from the laminated Santa Barbara Basin sediments. In San Nicolas Basin the integrated radon excess in the water column is 376±143 atoms/m2 s, but the diffusive randon flux from San Nicolas Basin sediments averages only 190±53 atoms/m2 s. This descrepancy indicates that a non-diffusive process, probably macrofaunal irrigation, supplies much of the flux of radon from San Nicolas Basin sediments. 相似文献
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Abstract The design and construction of a special-purpose laboratory catchment and rainfall simulator is described. The equipment consists of a soil catchment area that can be inclined at various angles. Additional instrumentation then measures the flow of water across the surface of, and through, the soil bed. Precipitation is provided by a unit that simulates rainfall at particular rates with uniform distribution. The equipment was used to examine infiltration, runoff and other hydrological properties of a number of soils under different rainfall intensities and with different catchment slopes. Correlations were obtained for these variables. 相似文献