~(90)Y在不同材料器壁上的吸附性能

用HDEHP萃取法从高放废液中提取了90Sr,对137Cs的去污因子约为800。以90Sr-90Y为示踪剂,在不同pH条件下对90Y在聚丙烯、聚乙烯、玻璃等材料管壁上的吸附进行了研究。结果表明,在pH=0~10范围内,3种材料的管壁吸附90Y的变化趋势基本一致。当pH3时,90Y在3种材料上基本不吸附;当pH3时,90Y在3种材料上均有较大的吸附,且在玻璃上的吸附远大于在聚丙烯和聚乙烯上的吸附;对于聚丙烯和聚乙烯2种材料,当pH7时,90Y在聚丙烯上的吸附大于在聚乙烯上的;pH7时,情况相反。根据实验结果,在90Sr-90Y的实验中,应尽量选用聚丙烯或聚乙烯作为容器,且溶液的pH值应小于3。     

核电厂在役检查计划与协调

基于核动力运行研究所(RINPO)在广东大亚湾核电站役前检查和在役检查的实践经验,并结合我国在役检查的特点,简要阐述了在役检查的前期准备和计划,包括对检查组织机构、检验设备/工具、检验技术,备品备件及消耗材料、检验人员和检验文件的要求;同时,重点介绍了在核电站大修期间,如何在有限的时间、人力和特定环境下科学地、周     

IAEA及其总干事巴拉迪获诺贝尔和平奖

【本刊2005年10月综合报道】诺贝尔委员会2005年10月7日在挪威首都奥斯陆宣布,将2005年诺贝尔和平奖授予国际原子能机构(IAEA)和该组织总干事巴拉迪,以表彰他们在阻止核能在军事领域内的使用以及在和平利用核能等方面的卓越贡献。评委会在公告中说,IAEA近年来在阻止核能在军事领域的使用和加强民用核能的安全性方面做出了突出贡献,总干事巴拉迪是该组织勇敢和优秀的代言人。在核裁军努力看似陷入僵局的时候,在核武器可能流入一些国家或恐怖组织手中的时候,以及在核能再次显现出越来越重要作用的时候,IAEA及其总干事巴拉迪的工作具有不…     

正电子直线加速器俘获节加速场梯度对俘获率的影响

一、引言在正电子直线加速器中,正电子在靶上生成,经过一段匹配段,进入加速管。通常称这根加速管为俘获节。俘获节的加速场梯度如何影响正电子的俘获率,是在加速器设计和运行过程中很感兴趣的一个问题。所谓俘获,指的是,粒子在横向不碰到系统管壁,在纵向聚到一定相位范围,且在俘获节末端的能散度不超过某个限度。这样,正电子在以后的加速过程中,一定相宽内粒子数的多少将决定最终束流能谱的好坏。     

核电厂在役检查计划与协调(英文)

基于核动力运行研究所(RINPO)在广东大亚湾核电站役前检查和在役检查的实践经验,并结合我国在役检查的特点,简要阐述了在役检查的前期准备和计划,包括对检查组织机构、检验设备/工具、检验技术、备品备件及消耗材料、检验人员和检验文件的要求;同时,重点介绍了在核电站大修期间,如何在有限的时间、人力和特定环境下科学地、周密地计划和安排在役检查各种活动以及加强现场协调和管理的必要性,从而保证在役检查任务的顺利完成。     

强磁防垢除垢磁化器在锅炉上的应用

水中溶解物质的结晶可以以壁面粗糙点为核心直接形成在受热面壁上,也可以以水中的胶体质点、气泡及其它物质的悬浮点为核心形成在水溶剂中。在壁面上结晶的将在金属表面上形成坚硬而质密的沉淀物,称为水垢。 水垢是在各种热交换器设备中形成的一种粘附力很强的坚硬结晶物,其主要成分是钙镁盐类,其危害性主要表现在:导热性差,阻碍热交换,影响传热效率,增加能源消耗,增加流阻,消耗人力物力大,降低设备利用率,威胁生产等等。水垢有这些特点,而它又几乎在我们的日常用水设备中无处不在,给我     

巴基斯坦苏来曼山锡瓦利克砂岩铀矿床

在巴基斯坦苏来曼山区,已知的含铀透镜体分布在沿苏来曼山麓100余哩长条地带内的七个地方。最好的露头在巴格哈耳·楚尔,在那里已做了大量的钻探工作。在巴格哈耳·楚尔及其他地方,氧化带的铀矿物主要是准钙钒铀矿,而在非氧化带,铀矿物则是晶质铀矿或铀石。矿化透镜体长与宽可达300呎,厚7—9呎。矿化控制尚不清楚。隆起的喜马拉雅山的剥蚀,被认为是这些地区铀矿的来源,铀被搬运并沉积在苏来曼山脉的问题仍在研究。     

Co~(60)γ射线对春小麦植株当代性状变异及对其后代影响的初步观察

辐射育种是电离辐射在农业上应用的一个重要方面,在作物育种工作中具有特殊意义。近年来国内外的研究资料表明:用较高剂量辐射照射作物种子,可以显著地增加突变频率,并且在变异的深度上也大大地超过其在自然条件下的自发变异;可以获得在自然界很少存在的新类型。此外,在适当的剂量条件下,辐射可以改善作物品种的某些单一特性,而不损害     

两年来世界发现大量铀矿床

最近二年,外刊关于世界铀矿资源和铀矿普查勘探情况的报道日益增多。尽管报道比较零乱而且很不具体,但仍可以看出,在目前世界能源紧张的形势下,各国都在积极寻找出路,解决能源不足的问题。综合外刊最近大量报道的材料,可以看出在过去的两年里,各国在寻找铀资源方面,经过了相当的努力,发现了一批新矿。值得注意的是,这些新发现的铀矿床,不少是在新区和在找矿思想上有了     

印度、巴基斯坦发誓要减少核冲突的危险

【法新社伊斯兰堡 10月 18日电】　印度和巴基斯坦 10月 17日发表联合声明 ,发誓双方将减少核冲突的危险 ,并将继续努力 ,为克什米尔主权纠纷寻求解决方案。印、巴两国在伊斯兰堡举行的三天会谈昨天结束。由两国外交部秘书率领的代表团决定在 1999年 2月上旬在新德里举行另一轮会谈 ,议题集中在和平、安全、克什米尔以及互信措施。声明说 :“双方将在核和常规领域建立互信 ,以减低冲突的危险。”在 2月会谈举行之前 ,印、巴两国 11月间将在新德里会谈 ,讨论其他议程。巴基斯坦曾呼吁联合国在克什米尔举行公民表决 ,但印度表明它对克什米尔的…     

Identification of radiation treatment of wheat （Triticum aestivum. L）and rice （Oryza sativa. L） samples using thermoluminescence of contaminating minerals

Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence （TL） is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture （NIFA）, Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities （TL1） than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves （TL2）. The ratio of the area of first glow curve to that of second glow curve （TL1/TL2） was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results （comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves）, all the irradiated and unirradiated samples of wheat and rice were unequivocally identified.     

有效探测面积大于1000 cm2的正比计数器测量系统性能测试

为对自制的活性面积高达1 000 cm²的大面积源进行表面发射率定值,同时作为现有2πα、2πβ表面发射率标准装置能力的扩充,研制了一套内置式大面积2π多丝正比计数器测量系统,并利用活性区直径为8 mm的²⁴¹Am点源及活性区面积为10 cm×15 cm的大面积²⁴¹Am和⁹⁰Sr-⁹⁰Y源对其进行计量学性能测试。结果表明：计数器内计数响应均匀性优于±0.4%,有效探测面积达1 400 cm²;所得²⁴¹Am源高压坪曲线的坪长为1 400 V,坪斜为0.27%/100 V,坪区内计数变化为0.87%;⁹⁰Sr-⁹⁰Y源高压坪曲线的坪长为300 V,坪斜为0.75%/100 V,坪区内计数变化为0.80%;10次测量重复性好于0.4%,8 h内短期稳定性好于0.3%,1 a内长期稳定性好于0.8%。     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn （11）. When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.     

Current status of radiation therapy for prostate cancer

Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

Interaction between uranium and humic acid (Ⅰ): Adsorption behaviors of U(Ⅵ) in soil humic acids

The adsorption behaviors of uranium on three soil humic acids (HAs), which were extracted from soils of different depths at the same site, were investigated under various experimental conditions. The adsorption results showed that U(Ⅵ) in solutions can be adsorbed by the three soil HAs, with the order of FHA (HA from 5 m depth of soil) ＞SHA (HA from the surface) ＞THA (HA from 10 m depth of soil) for adsorption efficiency in each desirable condition, and the adsorption reached equilibrium in about 240 min. Although the maximum adsorption efficiency was adsorption could be described with Langmiur isotherm or Freundlich isotherm equation. The L/S (liquid/solid, mL/g)ratio and pH were important factors influencing the adsorption in our adsorption system besides uranium concentration. The adsorption efficiency decreased with the increase of the L/S ratio and pH at the pH range of 2.0-3.0 for SHA and THA or 2.5 - 6.0 for FHA. However, no significant difference in adsorption of U(Ⅵ) was observed at the experimental temperature. All the results implied that humic substances have different characteristics in samples even collected at the same site.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现：从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。     

Information for authors

<正>1.NUCLEAR SCIENCE AND TECHNIQUES(NST),a bimonthly journal,is devoted to all aspects of nuclear science and technology,theoretical or experimental.Its special interest lies in the subjects of synchrotron radiation science and technology;low energy accelerators,radiation technology and applications;radiochemistry,radiopharmaceuticals and nuclear medicine;nuclear electronics and instrumen-     

PLASMA SCIENCE AND TECHNOLOGY AUTHOR INDEX TO VOLUME 16(2014)

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Web Services interface of SSRF archive data analysis system

Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.