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1.
核外环境对衰变率的影响   总被引:1,自引:0,他引:1  
核衰变速率是否受核外环境影响, 一直是核物理研究的热点问题。 这一问题不仅对核物理基础研究很重要, 而且与天体物理、 地质年代学、 凝聚态物理和核废物处理等都有重要关系。 旨在对这方面研究工作的进展做一介绍。The possible change of nuclear decay rates in different environments has long been an interesting topic due to its importance not only in nuclear physics but also in astrophysics, geological dating, condensed matter physics, disposal of nuclear waste etc. The progresses in the investigation of variations in nuclear decay rates are reviewed.  相似文献   

2.
将84个清凉寺窑汝官瓷和钧台窑钧官瓷样品进行质子激发X射线荧光分析,得到每个样品胎和釉的7种主量化学组分。将所有样品的7种主量化学组成数据进行散布分析,以确定汝官瓷和钧官瓷原料来源是否相同。从散布分析图可以看出,汝官瓷釉和 钧官瓷釉样品的原料产地和配方明显不同,汝官瓷胎和钧官瓷胎样品的原料产地和成分接近,但有所不同。The seven main chemical components of the body and glaze samples of 84 RuGuan porcelains from Qingliangsi kiln and JunGuan porcelains from Juntai kiln are determined by the proton induced X-ray emission ( PIXE). Then these data are analyzed by scatter analysis to confirm whether the sources of the raw materials of Ru-Guan porcelain from Qingliangsi kiln and JunGuan porcelain from Juntai kiln are the same or not. The figure of the scatter diagram shows that the sourcing area of the raw material and batch formula of RuGuan porcelain and Jun-Guan porcelain glaze are obviously different and the sources of the raw materials and components of their body samples are close but a bit different.  相似文献   

3.
Nuclear analytical technique is an efficient method in study of rarity cultural relic for its advantage of nondestructive analysis. Longquan celadon is one kind of the most important ancient porcelain in China. In order to determine the inner provenance property and age's characteristic of ancient Longquan porcelain, ten components in porcelain body and glaze were measured by the Wave Dispersive X-ray Fluorescence (WDXRF). Multivariates Statistical Analysis was used to analyze the experiment data. The results showed that the chemical compositions in porcelain body of three typical kilns were similar. The difference of components in porcelain glaze can be used to identify the provenance and age.  相似文献   

4.
以黄冶窑四个时期的白瓷样品作为研究对象,利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对样品进行分析,结果表明:黄冶窑白瓷胎的物相基本相同,主要是莫来石、α石英和方石英、未熔石英和少量的粘土相;黄冶窑白瓷釉中有气泡存在,釉中气泡为圆形,釉中存在微米级的针状或柱状钙长石晶体,釉存在分相结构,且分相结构与析晶相伴而生;黄冶窑白瓷胎中有气孔、未熔的石英颗粒、较大的Ti颗粒、莫来石晶体和石英晶体。The white porcelain samples of the four periods of Huangye kiln were studied in this paper, and the samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the material phase is basically the same of the white porcelain bodies from Huangye kiln, and mainly mullite, alpha quartz and cristobalite, unmelted quartz and a small amount of clay phase; There are some round bubbles in HuangYe kiln white porcelain, glazes, so are some feldspathic crystals with micro-level needles or columnar. It is evident to observe phase separation structure, which is accompanied by the birth. Apart from some pores, unfused quartz particles, larger Ti particles, mullite crystals and quartz crystals can also be found in the embryo of Huangye kiln white porcelain.  相似文献   

5.
A mass of Longquan celadon shards were excavated from the Chuzhou site of Huai'an City in Jiangsu Province, China. These celadon shards were fired during the period of the Late Yuan Dynasty to the Tianshun era of the Ming Dynasty, as identified by archaeologists at Nanjing Museum. In order to research the chemical composition features of this ancient celadon porcelain, energy dispersive X-ray fluorescence (EDXRF) for non-destructive analysis was used to determine the chemical composition of the porcelain body and glaze in these shards. The results indicate that Ti and Fe in the body of Longquan celadon are characteristic elements which can distinguish porcelain produced during the Late Yuan Dynasty from those produced in the Ming Dynasties. The results of the principal component analysis (PCA) show that different body and glaze raw materials were used for the production of porcelain in different periods and the raw materials of the body and glaze are also different for various vessel shapes. The chemical compositions in the porcelain body of civilian ware are slightly different. The imperial and civilian Longquan celadon porcelains produced during the Hongwu era to the Tianshun era of the Ming Dynasty are distinguishable by the MnO, Fe2O3, Rb2O and SrO content in their porcelain glaze.  相似文献   

6.
采用能量色散X射线荧光(EDXRF)技术测试了若干严和店窑汝瓷和钧台窑钧官瓷样品胎和釉的化学组成, 利用多元统计中的因子分析方法分析了两窑场胎和釉的差异。结果表明:严和店窑汝瓷和钧台窑钧官瓷能较好地加以区分。再次证明了钧瓷和汝瓷是有区别的。 The chemical components of the body and glaze samples of some Ru porcelains from Yanhedian kiln and Jun official porcelains from Juntai kiln are determined by the technology of Energy Dispersive X ray Fluorescence(EDXRF) in this work. The difference of the two kiln’s glaze and body are analyzed by factor analysis method of Multi dimensional statistical analysis. The results indicate that Yanhedian Ru porcelains can be well distinguished from Jun official porcelains from Juntai kiln. This evidence once again proves that Jun ceramics and Ru ceramics can be distinguished obviously.  相似文献   

7.
核材料辐射出的γ射线对人体有很强的辐射损伤, 实际工作中多用铅玻璃对其进行屏蔽。 以甲状腺为研究对象, 应用蒙特卡罗方法通用软件MCNP4B程序建立模型, 模拟计算了操作人员在操作核弹头时, 弹头中产生的γ射线透过各种厚度的铅玻璃时人体甲状腺吸收剂量率。 结果表明, 铅玻璃确有良好的降低γ射线吸收剂量率的作用。
The γ ray which is radiated from a nuclear material can cause serious radiation damage to human organs, so lead glass are often used as a shielding material. In this paper, thyroid was the subject investigated. A mathematical model was established by using the general software code MCNP4B. We have calculated a series of thyroid’s absorbed dose rate when the γ ray which was generated from the warhead penetrated the various depths of the lead glass via the model. The results indicate that lead glass work well as a protector against γ rays.  相似文献   

8.
选取耀州窑瓷胎样品25个,唐三彩的胎3个,作坊匣钵料样品1个,耀州博物馆附近粘土矿样品4个.用中子活化分析测量样品中29种元素的含量,从这29种元素中挑选出8种指纹元素,将指纹元素的含量进行散布分析.结果表明,出自不同窑口的古耀州瓷的胎,有着长期稳定的、集中的原料产地.耀州窑唐三彩的胎料产地和耀州瓷胎的原料产地相同.25 samples of Yaozhou porcelain bodies, 3 samples of the tri-color pottery bodies during the Tang Dynasty, 1 samples of Saggar material during Song Dynasty and 4 samples of clay mineral taken from the place near Yaozhou Kiln Museum was selected . The technique of neutron activation analysis (NAA) has been employed to measure the content of 29 kinds of elements in the samples. 8 elements of them were selected as fingerprint elements to make scatter analysis.The conclusion is that the ancient Yaozhou por...  相似文献   

9.
通过微米孔准直或电磁聚焦技术可将加速器产生的MeV离子束形成微米尺寸的离子束斑(微束), 从而用来研究固体和生物样品的微米空间分辨的材料信息和辐照响应。 结合MeV离子微束的发展历史综述了微束技术和跨学科应用, 包括利用微束开展具有空间分辨的离子束分析、 单粒子效应、 微纳加工和细胞辐射响应等研究。 介绍了中国科学院近代物理研究所的高能重离子微束辐照装置, 该装置成功地将总能量为1 GeV的C离子在大气中聚焦为1 μm×2 μm的微米束斑。 Beam of MeV ions from particle accelerators can be confined by collimators or focused by electrical/magnetic quadruples into micrometer size, and this microbeam can be used to obtain spatial information or radiation effect in solids and biological samples. This paper reviews the technical developments and the multi disciplinary applications of microbeam, including ion beam analysis, single event effect in semiconductor devices, proton beam writing and cellular response to targeted particle irradiations. Finally, the high energy heavy ion microbeam facility at the Institute of Modern Physics of Chinese Academy of Sciences is introduced, which has successfully focused 1 GeV Carbon ions into a beam spot of 1 μm×2 μm in air.  相似文献   

10.
采用把重离子碰撞的动力学和统计衰变过程相结合的一个两步模型,再现了INDRA Collaborations 对入射能为35 AMeV40Ca+40Ca 和48Ca+48Ca 反应的实验结果。进而得到了反应碎块同位素分布的Isoscaling 参数α(Z) 和β(N),约化对称能系数ζ(Z) 及与平均场中的对称能强度系数Cs 之间的关系。结果表明,Isoscaling 参数强烈依赖于系统的丰中子程度。随着质子数的增大,ζ(Z) 在动力学阶段呈现平缓趋势但在衰变之后呈现上升趋势,且该结果不依赖于所选取的反应系统。对称能效应在统计衰变过程之后的末级碎块分布中有明显表现。A two-step model for combining the dynamical and statistical decay processes in heavy-ion collisions is used to reproduce the experimental results of the INDRA Collaborations on 40Ca+40Ca and 48Ca+48Ca reactions at 35 AMeV. We obtain the isoscaling parameters α(Z) and β(N) of isotopic distributions of the fragments, the reduced symmetry energy coefficient ζ(Z) and its dependence on the symmetry energy strength coefficient Cs in the mean field. Our results suggest that Isoscaling parameters strongly depend on the degree of neutron-rich. With the increasing atomic number, ζ(Z) represents a smoothly flat tendency during the dynamical process but shows the increasing tendency after decay, and such results are independent on the selected reaction systems. The effect of symmetry energy shows evidently in the isotopic distributions of fragments after statistical decay process.  相似文献   

11.
为研究清凉寺窑汝瓷胎和张公巷窑青瓷胎的原料特征及来源, 选取37个清凉寺窑汝瓷胎样品(32个汝官瓷胎和5个汝民瓷胎)、 32个张公巷窑青瓷胎样品以及14个岩石样品, 用中子活化分析 (NAA)方法测得每个样品中的23种元素含量; 使用散布分析及主成分分析方法处理NAA数据。 结果表明: 元素Fe, Ce, Ba, Ta, Th, La, Sm和Cr可作为区分汝官瓷胎和张公巷窑青瓷胎原料产地的指纹元素; 汝官瓷胎原料产地较集中, 来源相对稳定; 清凉寺窑汝民瓷胎料产地与汝官瓷基本相同, 均为就地取材; 张公巷窑青瓷胎原料产地较为分散, 与汝官瓷不同, 但二者距离相近。 关  相似文献   

12.
黄冶窑文化内涵丰富,其创烧于隋,兴盛于唐代中期,停烧于唐代晚期。为探讨不同时期黄冶窑白瓷的胎料来源和釉料配方是否相同,选取黄冶窑隋、早唐、中唐、晚唐四个时期的80个白瓷样品,利用质子激发X射线荧光分析(PIXE)测定各样品胎、釉中9种化学成分(Na2O、MgO、Al2O3、SiO2、P2O5、K2O、CaO、TiO2、Fe2O3)的含量,用多元统计分析中的Fisher判别分析处理PIXE数据,并计算各样品釉的木灰釉式系数b来划分瓷釉类型。结果表明:黄冶窑四个时期的胎料取自同一或相近的地点,都是就地取材;四个时期的釉料配方比较相似,而四期白瓷的釉料配方最为稳定,且与二期釉料配方最相似,而与一期釉料配方已有明显不同;黄冶窑白瓷釉大部分为钙釉,存在少量钙碱釉和碱钙釉。  相似文献   

13.
The proton induced X-ray emission (PIXE) is used to determine the chemical ingredients of seven main elements in the samples of Ru Guan porcelain glazes and Ru Civil porcelain from Qingliangsi kiln in Baofeng County and the samples of celadon glaze from Zhanggongxiang kiln in Ruzhou City. The PIXE data are then analyzed by scatter analysis and fuzzy cluster method for determining their classification and provenance. The results show that there are obvious differences between the ingredients of glaze material of Ru Guan porcelain and Ru Civil porcelain from Qingliangsi kiln, of which the former ingredients are stable and its source is localized, and that the sources and ingredients of the glaze of Ru Guan porcelain and those of celadon glaze from Zhanggongxiang kiln are not wholly the same, of which the latter sources are much scattering.  相似文献   

14.
景德镇宋代以生产青白瓷而闻名,其中湖田窑又是景德镇宋代窑址中最典型的一处,其生产的青白瓷精巧细致,有“假玉器”和“饶玉”之称。研究采用能量色散X荧光光谱分析仪和色差计,分析了湖田窑宋代青白瓷的胎、釉化学组成和色度值,初步探讨了不同时期青白瓷的组成、配方和呈色特征。研究表明,湖田窑北宋和南宋青白瓷胎体组成特征基本一致,均与当地瓷石原料较为接近,极有可能采用了附近的三宝瓷石原料制胎。瓷釉组成结果显示釉中含有较高的CaO和一定量的MnO和P2O5,表明湖田窑青白瓷釉为“钙釉”,且釉料配方中引入了一定量的草木灰。色度分析结果显示,湖田窑北宋和南宋青白瓷釉主波长分别为500和496 nm左右,均落在可见光波的绿色波段。但对比北宋和南宋瓷釉组成和色度结果发现,北宋青白瓷釉无论是组成还是色度数据结果均较南宋更为分散,且南宋青白瓷釉层呈色相较北宋样品b值更小,釉色更为偏蓝。研究认为,湖田窑青白瓷从北宋至南宋,釉料配方经历了从探索逐渐走向成熟、稳定的过程。研究结果不仅为景德镇湖田窑青白瓷的断源断代提供了数据支撑,也为湖田窑青白瓷制瓷技艺的传承和传播提供了一定的科学素材。  相似文献   

15.
巩窑唐代早期白瓷的EDXRF线扫描分析   总被引:6,自引:1,他引:5  
具有悠久瓷器生产历史的巩窑,是我国古代北方烧制白瓷的3个代表性窑口之一。在唐代早期,为了掩盖瓷胎表面的粗糙状态和较深的胎体颜色,提高瓷器的质量和白度,巩窑白瓷在胎的表面施加了一层装饰层——化妆土。用能量色散X射线探针技术对这些白瓷碎片的剖面进行了主要化学成分的线扫描分析,结果表明: 巩窑唐代早期白瓷的化妆土使用了不同的原料,与光学显微镜下观察到的现象相符合。另外,白瓷釉可能是加有草木灰的钙釉。  相似文献   

16.
芜湖东门渡窑是古代宣州窑场的早期窑口之一,属古越窑系青瓷;该窑口出产的陶瓷产品器型别具一格,具有鲜明的地域特色.但长期以来,对于东门渡窑瓷器仅仅从其外观推测其工艺特征,对该类瓷器的微观结构特征和配方工艺特点缺乏必要的分析证据.为系统解析东门渡窑古陶瓷的胎、釉化学组成和烧制工艺,运用波长色散X射线荧光光谱法(EDXRF)...  相似文献   

17.
景德镇窑和德化窑是南方白釉瓷窑口中最具有代表性的两个窑口。该文利用能量色散X射线荧光光谱分析仪,对30件宋、元、明时期的德化白瓷以及元代景德镇枢府白瓷样品进行了测试,并从时空角度对比分析了不同白瓷样品胎釉的组成特征。结果表明,景德镇枢府白瓷胎釉组成铁含量均明显偏高,而德化白瓷胎釉组成中的钾含量均明显偏高,且随着时间发展具有上升趋势,这应是德化雕塑白瓷异军突起的主要原因。  相似文献   

18.
为了解繁昌柯家冲窑青白瓷釉化学组成特征及其演变过程,并探索我国南方早期青白釉的工艺技术来源,本文运用能量色散X射线荧光光谱法(EDXRF)分析了柯家冲窑五代至北宋中期不同阶段青白瓷釉的化学组成,并将分析结果与同时期北方定窑白瓷釉及南方越窑青瓷釉化学组成进行了综合对比研究。结果显示,繁昌柯家冲窑青白釉化学组成在北宋中期时发生了明显变化,其中尤以SiO2含量的下降和CaO含量的上升最为明显,着色元素Fe,Mn,Ti的氧化物含量自五代时期至北宋中期变化幅度很小,繁昌柯家冲窑青白釉釉色由偏白向偏青转变的原因可能与该窑瓷器胎色的不断加深有关。此外,主成分分析及具有相似功能特性的元素组合对比分析结果显示,繁昌柯家冲窑青白瓷釉的化学组成与北方定窑白瓷釉较为接近,其釉料配方工艺可能来源于同时期我国北方地区以定窑为代表的白瓷窑场。本文研究结果对了解我国早期青白瓷釉的化学组成特征及晚唐五代时期南、北方制瓷工艺技术交流问题等有重要学术价值。  相似文献   

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