SrSO4:EU和CaSO4:EU的热释光和光释光发光谱

测量了SrSO4：Eu(摩尔分数为0．1％)和CaSO4：Eu(摩尔分数为0．1％)的光释光发光谱和热释光发光谱,得到SrSO4：Eu的光释光发光波长与热释光发光波长均为375nm,而CaSO4：Eu的光释光发光波长与热释光发光波长均为385nm,说明热释光和光释光具有相同的发光中心,均来自于Eu^2 的能级跃迁。同时在CaSO4：Eu的热释光发光谱中还观察到了Eu^3 的发光。     

新疆阿舍勒铜矿石英的释光特征及矿床成因意义

对新疆阿舍勒铜矿中的石英进行了二维、三维热释光和光释光的分析,对该铜矿附近的凝灰岩、玛尔卡库里大断裂中的石英脉、金矿和花岗伟晶岩中的石英矿物进行了热释光、光释光的分析与对比.铜矿体中的石英的释光特征与凝灰岩、断裂带石英脉、金矿、花岗伟晶岩中石英存在较大差异.铜矿中石英在170℃有2个发光峰,波长段分别为340nm和405nm左右,而没有如金矿和断裂带石英中存在的与热液成因相关的560-590 nm附近的发光峰,也没有如花岗伟晶岩石英中存在的与深成岩浆作用有关的476nm和625nm附近的2个发光峰.结合对样品的稀土元素进行的中子活化分析,证明铜矿的形成与金的流体成矿不同,属于火山成因铜矿床.     

MgB4O7:Tb磷光体的研制及其热释光(TL)特性

以碳酸镁和硼酸为原料在高温条件下合成了基质材料MgB4O7并制备了MgB4O7：Tb磷光体。用Risφ／OSL-15-B／C热释光（TL）,光释光（OSL）自动测量仪和TL/OSL三维光谱自动测量仪分别测量了这种磷光体的二维热释光发光曲线和三维热释光发光谱。由MgB4O7：Tb的三维热释光发光谱可看出这种磷光体在230℃、340℃和420℃附近有三个热释光峰,发光谱的波长分别为489nm、548nm、589nm和620nm。此外,不同的高温烧结温度不仅对发光峰的发光强度有很大影响,而且还对。Tb^3＋发光谱形产生影响。当温度高于850℃时Tb^3＋离子发光谱线开始变成了发光谱带。     

α-Al2O3:C的光释光和LiF(Mg,Cu,P)的热释光比较研究

LiF(Mg,Cu,P)热释光探测器是最理想的热释光探测器.光释光(OSL)是新世纪发光剂量学的前沿,是辐射监测的一个新的发展方向.α-Al2O3:C是目前研究最深入的材料,也是目前唯一商用的光释光剂量材料.论文就光释光和热释光的基本原理、α-Al2O3:C和LiF(Mg,Cu,P)的发光灵敏度、动态范围、剂量响应、探...     

首都师范大学光断代实验室简介

首都师范大学光断代实验室是以研究结晶固体发光为基础的研究实验室 ,特别是对磷光体的发光机制进行理论探索 ,对具体矿物的发光过程积累实验资料尤有兴趣 ,为将来的释光矿物图谱编制打下基础。热释光的发光过程、固体发光的条件、固体对辐射的热释光响应、以及固体的热和光历史对发光的影响 ;磷光体释光 (热释光、光释光 )现象的应用研究 ,是年龄测定技术的基础 ,也是我们最感兴趣的研究领域。实验室以教书、育人、共同研究为宗旨 ,承担环境演变、考古和地质样品年龄测定及物源追踪、古物的不取样分析、各类辐射的固体剂量计的开发研究、微…     

掺Dy的MgB4O7磷光体的研制及其热释光特性

以碳酸镁和硼酸为原料在高温条件下合成了基质材料MgB4O7并制备了MgB4O7∶Dy磷光体.用RGD-3热释光剂量仪和三维热释光谱仪分别测量了这种磷光体的二维发光曲线和三维发光谱,实验观察到:1)MgB4O7∶Dy磷光体热释光发光峰峰温为220 ℃和380 ℃;2)Dy3 离子的发光波长为480 nm、575 nm和660 nm;3)磷光体220 ℃和380 ℃发光峰的相对强度随高温固相反应温度的升高而变化,但发光峰温和波长基本保持不变.对比MgB4O7∶Dy和MgSO4∶Dy两种热释光材料的三维发光谱,验证了掺入Dy3 离子的热释光材料的发光峰峰温主要由基质材料决定,发光波长则取决于Dy3 离子的能级跃迁的结果.     

α-Al_2O_3:C单晶的β辐射热释光与光释光性能研究

以高纯碳粉作为碳源直接加入原料,采用导模法(EFG)生长了α-Al2O3:C单晶。研究了晶体经过低剂量β射线辐照后的热释光与光释光特性,α-Al2O3:C单晶的热释光发光曲线在350 K、540 K和689 K附近有3个热释光峰,540 K附近为主要热释光峰,689 K附近为新的热释光峰,发现晶体的陷阱能级深度发生变化并产生了新深度的陷阱能级;随着β吸收剂量的增加,发光强度也随之增强,但是3个热释光峰温位置大致保持不变。在多次连续同剂量辐照过程中,随着辐照次数的增加,主热释光峰强度增强,峰温向高温方向偏移。α-Al2O3:C单晶的光释光衰减曲线呈指数变化,其由前期快衰减部分和后期慢衰减部分组成,快衰减部分衰减速率随着吸收剂量的增加变化很小,而慢衰减部分衰减速率则有较为明显的减慢。在低剂量范围内(低于10Gy),热释光和光释光过程灵敏度不随吸收剂量而变化,剂量响应曲线呈线性的特点。     

荧光玻璃、热释光和光释光探测器性能比较

介绍了荧光玻璃探测器、热释光探测器和光释光探测器基本原理和近期发展,并总结了荧光玻璃、热释光探测器、光释光探测器的优缺点.荧光玻璃最大优点是长期稳定性好和可多次读取.热释光和光释光探测器具有灵敏度高、低探测阈、较好的稳定性和能量响应、环境适应性强等优点.但与LiF:Mg,Cu,P相比,α- Al2O3:C光释光探测器对...     

芙蓉石的三维热释光谱

对新疆阿尔泰地区的芙蓉石及其围岩-白色半透明石英进行了三维热释光谱的分析.芙蓉石在170℃有2个低温热释光峰,发光波段分别为480 nm和630 nm,而白色石英只有480 nm 1个低温峰.480mm波段处的热释光峰是深成岩浆岩石英中最常见的峰,释光中心是Si位置上的(AJO4)0;表明芙蓉石是深成岩浆作用形成的.630 nm、170℃-210℃处的低温热释光峰是芙蓉石的特征热释光峰,可能是由于Fe3+置换Si4+晶格位置形成的[FeO4]0芯所引起的.本文还检测到芙蓉石和围岩石英在990nm、330℃处存在很强的高温热释光峰.     

湖光岩砂石的释光剂量研究

采集湖光岩玛尔湖周围部分岩洞内的岩样及岩壁下和湖岸边的砂土样品,用粗颗粒法测量它们的热释光和光释光;用复合作用剂量响应模型分析热释光和光释光剂量响应,并计算对应的热释光和光释光古剂量。结果表明:相同采样点的样品,热释光和光释光古剂量间都存在一些差异;不同采样点样品的释光剂量相差很大;热释光古剂量测量值较准确的样品,光释光古剂量测量值与热释光测量值无显著的数量级差别。此测量分析对第四纪火山考古有一定参考意义。     

Possible use of a BGO array for neutron stimulated emission computed tomography by summing adjacent signals

Neutron stimulated emission computed tomography (NSECT) is a new approach for biological spectroscopy and imaging. Since the gamma-ray photons emitted from stimulated element have energies from 100 keV to about 6 MeV, previous reports have proposed that the projection path can be defined by the neutron beam. In this paper, another possible method has been applied and the performance presented through simulations. When using signals from a single BGO crystal it is impossible to achieve good energy resolution for such high-energy photons. When summing additional signals from adjacent crystals, the energy spectrum becomes much better. Using an energy window with energy resolution of 90 keV, an average intrinsic spatial resolution of 3.938 mm FWHM is obtained.     

基于信号功率谱梯度分析的n-γ甄别方法研究

发现了液体闪烁体探测器在分别与中子和γ射线作用时输出脉冲的功率谱梯度存在较大差异这一特征,由此提出一种基于脉冲信号的频域特征参数来甄别中子和γ射线的方法--功率谱梯度分析（SGA）法。本文论述了SGA法的基本原理及其可行性,并通过伴随粒子中子飞行实验验证了SGA法n-γ甄别结果的正确性。研究了SGA法在采样率从5 G/s逐步递减到250 M/s下甄别性能的变化。结果表明,与基于时域特征的n-γ甄别方法相比,SGA法对噪声较不敏感,抗干扰能力强,甄别性能更为稳定且计算量小。     

Optically stimulated luminescence dosimeter based on CaS：Eu,Sm

Alkaline earth sulfides (MgS, CaS and BaS) crystal doped with rare-earth ions is an optically stimulated luminescence dosimeter with very high sensitivity, short time constant of the optically stimulated luminescence (OSL)separated perfectly from the stimulation. In this paper, an OSL dosimeter is described. It has linear dose response from 0.01 to 1000 Gy. The equipment, relatively simple and small in size is promising for applications in space exploration and for high dose irradiation and dangerous irradiation conditions.     

TEVA树脂分离-ICP-MS测量钍基体中微量铀

针对233 U提取工艺1AW钍基体中微量铀(m(Th)/m(U)=105)的分析,以TEVA树脂萃取色谱为主要分离纯化手段,以ICP-MS为测量手段,建立了一个简便快速的分析方法。上柱时模拟料液的体积为1mL、酸度为2.5mol/L,铀的洗脱液为12mL硝酸(2mol/L),方法对1AW模拟样品中铀的回收率为97.1%~100.0%,sr=1.1%(n=5)。该方法能够有效地将钍基体去除,从而实现微量铀的准确测量。     

一种直接测量穆斯堡尔谱小能量移位和弱线的方法

本文描述了一种利用穆斯堡尔色散结合共振过滤的简易方法,直接测量穆斯堡尔谱小能量移位和弱线成份。用不同厚度的吸收体作吸收补偿,可从穆斯堡尔色散谱中直接测得较精确的谱线小能量移位(可小至0.01mm/s)和从强的背景谱中直接分离出弱相的谱线(小于5％的相成分)。这种方法适宜于辐照样品、非化学计量的化合物、组分不同或有少量杂质的合金和腐蚀样品的穆斯堡尔测量。     

Radiation effects in atomic cryogenic solids

Radiation effects and relaxation processes in atomic solids are discussed with the example of solid Xe preliminarily irradiated by an electron beam. The study was performed employing concurrently the combination of current and optical “activation spectroscopy” methods. Three relaxation processes were monitored simultaneously upon controlled warming-up of pre-irradiated solids: thermally stimulated exoelectron emission (TSEE), thermally stimulated luminescence (TSL) in the VUV range and the total desorption yield by pressure measuring above the sample. Anomalous strong low-temperature “post-desorption” (ALTpD) of own atoms from pre-irradiated Xe solids was observed for the first time. The data obtained demonstrated a clear correlation between the yields of exoelectrons, photons of recombination luminescence and neutral particles pointing to the common origin of the phenomena. It was shown that the key primary process of the relaxation cascade including the ALTpD is a thermally stimulated electron detrapping, promoting electrons into the conduction band. Subsequent branching of the relaxation paths results in the relaxation emissions observed. An accumulation of charges of both signs as well as excess electrons under exposure to an electron beam was found.     

^41Ca示踪-AMS法测定细胞胞浆内Ca^2＋浓度的方法研究

^41Ca示踪剂是理想的生物医学示踪剂。本工作首次将^41Ca示踪剂用于测定在石棉作用下引起人肺成纤维细胞(HLF)胞浆钙离子浓度。采用体外培养的HLF作为研究对象，用石棉进行染毒，用超声破碎离心提取细胞胞浆制备生物样品，并对样品进行加速器质谱(AMS)测量。研究结果初步证明可将^41Ca示踪-AMS法用于石棉作用下HLF细胞的胞浆钙离子浓度分析。该方法有可能应用于生物学领域，为深入研究生命活动的机理提供分析手段。     

Influence of water content on the inactivation of P. digitatum spores using an air–water plasma jet

In order to investigate whether an air–water plasma jet is beneficial to improve the efficiency of inactivation, a series of experiments were done using a ring-needle plasma jet. The water content in the working gas(air) was accurately measured based on the Karl Fischer method. The effects of water on the production of OH(A~2Σ~+–X~2Π_i) and O(3p~5P–3s~5S) were also studied by optical emission spectroscopy. The results show that the water content is in the range of 2.53–9.58 mg l~(-1), depending on the gas/water mixture ratio. The production of OH(A~2Σ~+–X~2Π_i) rises with the increase of water content, whereas the O(3p~5P–3s~5S) shows a declining tendency with higher water content. The sterilization experiments indicate that this air–water plasma jet inactivates the P. digitatum spores very effectively and its efficiency rises with the increase of the water content. It is possible that OH(A~2Σ~+–X~2Π_i) is a more effective species in inactivation than O(3p~5P–3s~5S) and the water content benefit the spore germination inhibition through rising the OH(A~2Σ~+–X~2Π_i) production. The maximum of the inactivation efficacy is up to 93% when the applied voltage is -6.75 kV and the water content is 9.58 mg l~(-1).     

Evaluations of dielectric property and drug release profile of 5-FU patches based on plasma charged electrets

In the present study, the electret 5-fluorouracil patch was developed, the effective surface potential, piezoelectric coefficient d33, open-circuit thermally stimulated discharge (TSD) current spectra and shear adhesion of the patch were measured. The drug release profile of the patch was determined by using high performance liquid chromatography method. A stable potential difference which was positively dependent on the surface potential of the electret was generated on two sides of the patch. The measurements of d33 coefficient, TSD current spectra and adhesion performance showed that the electrostatic field of the electret could cause polarization and cohesive strength decreasing of the matrix molecules, change the distribution and interaction of the drug molecules in patch, therefore to increase the release of drug from the transdermal patch.     

佛波醇酯和人外周血促α照射致细胞恶性转化频率增加的研究

旨在观察佛波醇酯（ＰＭＡ）和人血多形核白细胞（ＰＭＮ）产生的氧自由基对α粒子致细胞转化频率（ＴＦ）的增加效应。Ｃ３Ｈ１０Ｔ１／２细胞经０．５、１．０和１．５Ｇｙα粒子照射后加入ＰＭＡ及ＰＭＡ刺激的人血，测定存活分数和ＴＦ，由１２５０个皿的实验所得初步结果看出，ＰＭＡ能刺激照射的Ｃ３Ｈ１０Ｔ１／２细胞增殖，并依赖于接种细胞密度和照射剂量，ＰＭＡ使０．５Ｇｙ照射的细胞ＴＦ增高２．１倍，ＰＭＡ刺激的人血增加２．８倍。