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1.
高探测效率的闪烁室测氡是氡测量的主要方法,但其取样结束后需静置3 h才开始测量.为实现闪烁室快速测氡的需要,在Rn-222、Po-218和Bi-214的探测效率相同的条件下,依据氡及其子体的衰变关系,本文建立了一种闪烁室测氡仪快速定值的方法.此法基于积分计数法,利用测量周期为60 min时的刻度因子K0,计算测量周期为30 min和15 min的理论刻度因子.本文选取对氡及其子体探测效率近似100%的54 mL小闪烁室,在氡浓度为20 Bq/mL的条件下开展快速定值实验.实验结果表明,本文测量的实验值与理论值误差在5%以内,能够实现闪烁室快速测氡.  相似文献   

2.
姚磊 《科技资讯》2014,(13):110-111
氡室是一种可以对氡探测器进行刻度标定及其性能测评,氡及其子体的相关研究提供一个测量模拟环境的仪器。氡室的工作运行温度是在-5℃~+40℃内,在对氡探测器进行测评是,室内温度要保持常温的情况下,温度和湿度被氡室控制和调节。论文介绍了HD-6型氡室的基本结构,研究了氡室内氡浓度变化规律,探讨了补氡过程对氡及子体平衡关系的影响。根据测量原理进行方法选择,并且对整个测量系统的组成部分进行详细分析。根据氡及其子体的放射平衡关系,将补氡区域进行浓度划分,对补氡过程中实际测量数据进行数值分析,通过分析结果探讨了温湿度、气溶胶因素对氡室内补氡过程中产生的影响。为以后HD-6型氡室的补氡动态过程提供了实际数据参考和影响因素的分析。  相似文献   

3.
针对同位素测氡法探火工作量大,周期长,易受气候及环境因素制约的问题,利用氡在向地表运移过程中产生的,能精确反映母体氡在一段时间中的累积值的固态长寿命子体210Po,提出了基于放射化学分析手段测定210Po活度浓度探测隐蔽矿井火区的氡子体210Po法探火。为了探究氡子体210Po法探火在现场探测中的效果与精度,在已知火源位置的柳湾煤矿开展了现场实验研究,在井下火区对应地表位置进行网格测点布置,对测点处的氡气浓度及其固态长寿命子体210Po的活度浓度进行测量。通过比较氡气浓度与210Po活度浓度探测结果相关性及其影响因素,对利用氡子体210Po探测采空区煤自燃火源位置的技术进行论证。结果表明,火区近地表土壤层氡气浓度与210Po活度浓度在总体分布上具有很强的相关性,但210Po活度浓度受外界因素干扰较小,其分布更能准确反映井下煤自燃火区情况。相比同位素测氡法,氡子体210P...  相似文献   

4.
准确测量环境高浓度氡是评价高氡浓度场所氡年释放量及辐射危害的必要工作,通过基于高纯锗γ谱仪测量技术,利用特制的采样测量盒,建立了测量高氡浓度的方法及装置。实验结果表明:该测量方法探测效率为7. 16×10~(-3),采样盒放于高纯锗探头表面条件下所对应的探测上限可达1×10~(11)Bq/m~3,探测下限为5. 5×10~4Bq/m~3;与闪烁室测氡方法进行了高氡浓度测量比对,两者相对偏差在2%以内。  相似文献   

5.
针对闪烁室测氡仪在多种采样方式的刻度系数,以FD125氡钍分析仪为实验仪器,分别对真空法、循环法和连续监测法等3种采样方式得到的刻度系数进行对比研究.结果表明,不区分采样方式使用同一刻度系数会引入较大的测量误差.通过对比分析3种采样方式的效率因子,得出循环采样法采样时间为10 min的采样效率最高,真空采样法的效率最低,而且循环采样法其采样时间越长,采样效率越高,但循环采样时间过长会影响氡与其子体的平衡,降低效率因子.  相似文献   

6.
净化空气中的氡子体是室内降氡技术手段之一.为了有效地检测空气净化器净化室内空气中氡子体的效率,设计了一套远距离测量α潜能浓度(Cp)的系统,并将该系统在容积为13.5m3的标准氡室里进行了严格的刻度.同时测量Cp和瞬时氡浓度(CRn)就可以求出可比的平衡因数F,对完善该检测方法进行了讨论.  相似文献   

7.
为提高辐射环境监测数据的准确度,对空气伽马吸收剂量率影响因素进行了研究。针对空气伽马吸收剂量率两个主要影响参数—空气氡及其子体浓度和相对湿度,分别进行了室内外本底测量、增加氡浓度和改变相对湿度实验。采用闪烁室测氡仪(ZnS(Ag)型)、静电收集室测氡仪(RAD7)和电离室测氡仪(AlphaGUARD)测量空气氡浓度,用X-γ剂量率仪(CKL-3120)测量空气伽马吸收剂量率。联合观测空气伽马吸收剂量率、空气氡浓度、温度、相对湿度和大气压强,实验结果表明:空气氡浓度、相对湿度与空气伽马吸收剂量率呈现弱的正相关。  相似文献   

8.
被动积分测220Rn方法及其应用   总被引:3,自引:0,他引:3  
利用氡^220Rn半衰期的差别、氡^220Rn及其子体释放的α粒子能量的差别以及^220Rn子体产生初始带电荷的特性,研究了平行氡^220Rn测量方法、吸收体法^220Rn水平测量方法及驻极体灵敏测^220Rn方法.这些方法在环境^220Rn水平监测、介质表面^220Rn出率的测量、室内^220Rn及其子体分布测量中得到了应用。  相似文献   

9.
谱仪的探测效率表征了探测器接收和记录信息的能力.为了更精确的测量α放射性核素的活度,定准α能谱仪的探测效率是非常必要的.本文利用查圆面源对窗的几何因子表和基于蒙特卡罗思想的MatLab模拟这两种方法对α谱仪探测效率进行了理论计算,并用Matlab软件对这两者所得的数据进行了比较分析,结果表明在5.5%的.对误差范围内两者可以近似相等.通过241 Am标准面源与氡子体标准源对α谱仪的探测效率进行了测量,发现用241 Am标准面源测得的探测效率与理论计算的探测效率相差很大,用氡子体标准源测得的探测效率与理论值符合的很好.研究表明241 Am标准面源的活度的均匀性与准确性以及尺寸定位的准确性是造成241 Am标准面源探测效率实验值与理论计算值差异的主要原因.  相似文献   

10.
利用放化分离提纯技术和α谱仪测量技术,建立针对可吸入颗粒物中~(210)Po的活度测量方法.通过自制小型氡室开展模拟实验,将聚四氟乙烯(PTFE)滤膜放入小型氡室密封60 d后,测量氡浓度变化情况,滤膜经过酸浸湿法消解处理后,利用~(210)Po在银片上的自沉积,通过低本底α谱仪对镀有~(210)Po的银片进行测量.结果表明,氡室内氡浓度维持在2×105Bq·m-3左右,氡衰变子体~(210)Po通过自沉降,能够在滤纸上检出较高~(210)Po活度,平行性好,适合开展氡及其子体模拟实验.  相似文献   

11.
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.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
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。  相似文献   

18.
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.  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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