闽南常用石材天然放射性核素含量分析

报道闽南常用石材的 33个样品中 ,天然放射性核素含量的分析结果 ,并按照国家有关石材产品分类标准进行划分 .分析结果表明 ,所采集的 33个石材样品 ,有 3个样品的天然放射性核素(2 2 6Ra,2 3 2 Th,40 K)含量异常偏高 ,其放射性比活度大于 C类控制值 ;而其余 30个样品的天然放射性核素含量处于正常本底水平 .所有石材比活度的范围 :2 2 6Ra为 15 .4～ 4 78.0 Bq·kg-1;2 3 2 Th为15 .3～ 6 6 9.3Bq· kg-1,40 K为 15 5～ 2 10 3Bq· kg-1.根据国家标准和建设部行业标准的要求 ,只有 11个石材样品 (其放射性比活度属于 A类控制值 ,内照射指数 MRa和外照射指数 Mr均小于 1)能用于住宅建设和内装修     

黑龙江省主要燃煤电厂粉煤灰天然放射性水平

为了解黑龙江省主要燃煤电厂粉煤灰天然放射性核素水平及其应用情况,采用低本底HPGeγ谱仪对样品中天然放射性核素含量进行测量。依据国家标准GB6566-2001,对其进行比较分析,结果表明,采集的粉煤灰中天然放射性核素水平属于正常水平,属A类建筑材料,不受应用限制。     

哈尔滨某电厂粉煤灰的天然放射性水平测量

为了解哈市某电厂粉煤灰中天然放射性核素水平及其应用情况，对其灰库内的粉煤灰进行取样测量，采用低本底HPGeγ能谱仪对样品中粉煤灰天然放射性核素含量进行测量。依据国家标准GB6566—2001，进行比较分析，结果表明，采集的粉煤灰中天然放射性核素水平属于正常水平，属A类建筑材料，不受应用限制。     

几种建筑材料中的放射性核素对环境的影响及其防治

花岗岩的石材产品 ,煤灰砖、大理石、硅酸盐、粘土及水泥制品等都是天然原料经加工的制成品 .然而人们极易忽视或者不了解赋存于这些原料中的天然放射性核素对环境的污染 ,危害人类健康 ,应引起高度重视 .1　放射性核素在建筑材料中赋存概况放射性核素在建筑材料中普遍存在 ,但其品位、种类及地区各有差别 .国家标准规定 :建筑、装饰材料的伽马辐射量不得大于 51 .6× 1 0 - 4 μC· kg- 1·h- 1 .衡阳医学院的测试结果 :灰渣砖、花岗岩、瓷砖等均超过上述国家标准 .此外 ,马赛克、木材、青砖及大理石等的值也很高 .花岗岩中的放射性核素 ,…     

江西某地区水中总α,总β放射性测量及评价

为了对江西某地区水中总α,总β放射性进行监测,对该地区的河水和井水进行采样,将样品分别进行浓缩、转移、洗涤、灼烧,经马弗炉高温灰化,采用BH1216低本底α、β测量仪测量水中总α、β放射性浓度.测量结果显示,井水水样总α、总β的平均比活度分别为0.045 9 Bq/L与0.1102 Bq/L;河水水样总α、总β的平均比活度分别为0.079 9 Bq/L与0.146 8 Bq/L,平均值均符合国家标准,少数井水样品与河水样品的总α比活度超过了国家标准.     

中国大陆主要省份土壤中天然放射性核素含量分布规律研究

综合了中国大陆28个省土壤中天然放射性核素238U,226Ra,232Th和40K含量的调查结果,分析了这些天然放射性核素含量分布现状和及其分布规律,初步探讨了引起部分省份放射性核素含量偏高的主要原因.研究结果表明,中国28个省市土壤中放射性核素238U,226Ra,232Th和40K的含量按面积加权平均值分别为39.5,36.5,49.1和580.0 Bq/kg;土壤中238U,226Ra,232Th的含量随地域的变化规律基本一致,40K含量随地域的分布规律则不显著.土壤中的天然放射性核素含量与成土母岩和铀资源分布有着明显的相关性.     

某引水工程天然放射性浓度水平及危害评价

通过对该引水工程南、北线工程涉及区地表岩土体γ照射量率;铀、钍、钾含量;土壤氡、水氡浓度水平以及库区水中总α、总β含量进行分析研究,结合《铀矿地质勘查辐射防护和环境保护规定》(GB15848-2009)、《生活饮用水卫生标准》(GB5749—2006)对工程涉及区进行天然放射性分析评价表明:库区天然放射性核素浓度水平较低,库区水体满足生活饮用水卫生标准;南线经过多处花岗岩体,天然放射性辐射较强,危害大;北线天然放射性辐射较南线弱,危害小,局部地段经过一定的防护,能保证引水工程的安全。     

β计数法测定水环境中的131I

131I是核医学应用中非常重要的核素,同时也是核泄漏事故中释放的主要裂变核素之一,其准确测定对于环境保护具有非常重要的意义.本文详细描述了不同水环境中的131I的β计数测定法,并对海水、放射性废水等不同水环境样品进行了检测,结果表明:1)本研究中碘的化学回收率为85.39%～94.47%,平均值为90.90%;2)海水样品平行样中131I的体积比活度为0.673 4～0.735 1 Bq/m3,放射性废水平行样中131I的体积比活度为16.80～17.43 Bq/m3,平行样研究结果表明此方法的重现性很好.     

湖北当阳铅锌伴生放射性矿污染调查与评估

为了掌握湖北当阳铅锌伴生放射性矿的辐射环境现状,在2009年5月至2011年7月期间,使用各种辐射监测仪器对该矿山的工作场所和生活区进行了氡及其子体浓度、空气y吸收剂量率、各种介质中天然放射性核素含量的测定.结果表明,坑道内氡气浓度、空气γ吸收剂量率以及各种环境介质中天然放射性核素含量分别为当地本底水平的179倍、12.3倍以及13～43.6倍;坑道内氡析出率为对照点的42.5倍.矿区职业人员及公众的年有效剂量均超过国家标准限值,应当采取必要的辐射管理措施对自然环境和工作人员加以保护.     

单纯形格子法研究掺渣建材产品放射性

工业废渣越来越多地被综合利用于建筑材料的生产。如果所掺工业废渣的天然放射性核素较高,容易改变或增加建材产品的放射性。以掺渣砌块为例,运用单纯形格子点设计和规划求解,建立掺渣砌块放射性数学模型,找出了最佳的原料配比和主要指标-混料因子之间的内在规律,得到了满足约束条件的优化配方。该方法为掺渣制品配方的确定及产品放射性的控制提供了重要参考。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has