湿度对CR-39固体核径迹探测器测量^220Rn／^222Rn水平的影响研究

在可调控温度、湿度及氡浓度的南华大学氡实验室对不同的湿度条件下CR-39固体核径迹探测器测量^220Rn、^222Rn的探测效率进行了测定,分析了湿度对CR-39固体核径迹探测器测量^220Rn、^222Rn探测效率的影响．实验结果表明：相对湿度在35％-95％范围内,当湿度为50％左右时,CR-39固体核径迹探测器测^222Rn,探测效率最高,标准偏差为2．0％;相对湿度在30％-100％范围内,当湿度为75％时,CR-39固体核径迹探测器测^220Rn的探测效率最低,标准偏差达到78．4％．     

Radon Levels in China

This paper reviewed and summarized the results and problems of a nation-wide environmental radon survey which was carried out from 1984 to 1990 in China. Indoor radon concentrations were measured in 10,811 dwellings, and which covered 26 provinces and cities all over China. The range of indoor radon concentrations was <LLD-386.8Bq·m^?3, the average was 22.5 Bq·m^?3 and 19.6 Bq·m^?3 for arithmetic mean and geometric mean, respectively. Both outdoor radon concentrations and indoor radon progeny concentrations were also reported. Even though the grab sampling was taken as the main method of the survey, it was still a valuable reference.     

Effect of the fungal protease EPg222 on proteolysis and texture in the dry fermented sausage ‘salchichón’

Proteolytic activity of the fungal protease EPg222 and its effect on the texture of the dry fermented sausage ‘salchichón’, which has a long ripening process, was assayed. Samples with enzyme added showed a significant reduction of myofibrillar protein concentration during the ripening period, compared with a control, and proteolytic activity of the enzyme led to a higher accumulation of non‐protein and ‐amino acid nitrogen. Analysis of volatile compounds in ripened dry fermented sausages revealed that only in EPg222 batches were branched compounds derived from amino acids catabolism detected that are associated with the flavour of dry cured meat products. The texture profile analysis showed reduction in hardness, gumminess and chewiness values in treated compared with control sausages. The effect of this enzyme could be of great interest in stimulating proteolysis, in flavour development and in reducing the hardness of dry fermented sausages produced by a long ripening process. Copyright © 2004 Society of Chemical Industry     

紫外线消毒反应器的生物验证试验研究

紫外线消毒技术存在无持续消毒效应、不能在线监测等缺点,因此为了保证紫外线消毒的安全可靠,必须对所设计的紫外反应器进行生物验证试验,以确保反应器的消毒效果和剂量。通过对加拿大紫外消毒反应器在不同透光率下的消毒效果和剂量进行研究,建立了该反应器所对应的紫外线剂量-灭活率曲线。结果表明,该反应器对MS-2噬菌体具有良好的灭活效果。     

Temporal variations of radon concentration in the saturated soil of Alpine grassland: The role of groundwater flow

Radon concentration has been monitored from 1995 to 1999 in the soil of the Sur-Frêtes ridge (French Alps), covered with snow from November to April. Measurements were performed at 70 cm depth, with a sampling time of 1 h, at two points: the summit of the ridge, at an altitude of 1792 m, and the bottom of the ridge, at an altitude of 1590 m. On the summit, radon concentration shows a moderate seasonal variation, with a high value from October to April (winter), and a low value from May to September (summer). At the bottom of the ridge, a large and opposite seasonal variation is observed, with a low value in winter and a high value in summer. Fluctuations of the radon concentration seem to be associated with temperature variations, an effect which is largely delusory. Indeed, these variations are actually due to water infiltration. A simplified mixing model is used to show that, at the summit of the ridge, two effects compete in the radon response: a slow infiltration response, rich in radon, with a typical time scale of days, and a fast infiltration of radon-poor rainwater. At the bottom of the ridge, similarly, two groundwater contributions compete: one slow infiltration response, similar to the response seen at the summit, and an additional slower response, with a typical time scale of about a month. This second slower response can be interpreted as the aquifer discharge in response to snow melt. This study shows that, while caution is necessary to properly interpret the various effects, the temporal variations of the radon concentration in soil can be understood reasonably well, and appear to be a sensitive tool to study the subtle interplay of near surface transfer processes of groundwater with different transit times.     

吸入短寿命氡子体的家兔全肺及气管基底细胞层的剂量估算

本文介绍了吸入短寿命氡子体所致家兔全肺和气管基底细胞层吸收剂量的估算方法。进行该实验是为了较准确地确定吸入短寿命氡子体所致肺组织剂量。并探讨全肺剂量及气管基底细胞层剂量之间的差别。实验结果指出,每单位α潜能暴露量在家兔全肺及气管基底细胞层产生的平均吸收剂量分别为0.71和0.91Gy/(J·h·m~(-3))或为0.25和0.32rad/WLM。     

东营凹陷盐222块沙四段上亚段有效储层识别

针对东营凹陷盐222块砂砾岩岩性复杂，非均质性强，岩石骨架对测井曲线的影响比常规砂岩储层突出的特点，在综合利用岩心、录井和常规测井资料的基础上，分析了盐222块沙四段上亚段的储层特征，建立了有效储层的判断标准，并对砂砾岩的有效储层进行了划分。研究结果表明，东营凹陷盐222块有效储层的物性标准为：岩性标准为含砾砂岩以下（包括含砾砂岩、细砂岩），含油性标准为油斑级以上（包括油斑），孔隙度大于等于6％，渗透率大于等于0．85&#215;10^-3μm^2；有效储层的电性标准为：声波时差大于等于197μs／m，补偿密度小于等于2．57g／cm^3，深侧向电阻率大于等于15Ω&#183;m。据此标准，对盐222块21口井341个层进行了有效储层的判断，有效储层即油层为313个，其中非油层转油层为50个，二次解释的结论与试油结果具有良好的对应性。     

The effects of oxygenation aeration treatment on dissipation behaviors of tricaine mesylate in carp (Cyprinus carpio) muscle and water

Tricaine mesylate (MS-222) is one of the most used anesthetics in fish. It can be absorbed by the human body via food consumption, with related detriments to human health. In this study, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was developed for the determination of MS-222 in carp muscle and water samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). For cleanup procedure, multiplug filtration cleanup (m-PFC) method with n-Hexane delipidation was adopted. The extraction solvent, cleanup methods and sorbents were optimized. All method validation parameters were in the acceptable range. The dissipation behavior study was followed by the method development. Firstly, the anesthesia dose and time were optimized in application study. Secondly, carps were revived for different period of time with (experimental group) and without (control group) the oxygenation aeration treatment to compare the dissipation rate of MS-222. After being anesthetized for 6 h at 50 mg/L and 12 h of elimination, the concentrations of MS-222 in crap muscle and water of experimental group was lower than those of control group. After 36 h of elimination under oxygenation aeration, over 90% of MS-222 was dissipated in carp muscle. The results showed that the half-life of MS-222 in carp muscle was 6.2 h. The findings suggested that the commonly-used oxygenation aeration treatment in aquaculture production had potential effects in accelerating the dissipation of MS-222 in carp and water. In this study, three days of withdrawal period was recommended in carps after MS-222 administration under oxygenation aeration.