Properties of intermediate-frequency vacuum arc in sinusoidal curved contact and butt contact

In this report,two new contact structures of a vacuum interrupter with a sinusoidal curved surface are proposed to improve the capability by increasing the surface area.The experimental investigation of vacuum arc at intermediate frequency(360-800 Hz)was conducted and the results were compared with a butt contact with the same contact diameter(41 mm)and the same material.By analyzing the arc behavior,arc voltage characteristics,arc energy,current interrupting capacity,ablation of the anode contact and condensation of the arc products at a 3 mm gap,the differences in their vacuum arc characteristics were determined.The correlations of their arc energy with the amplitude and the frequency of the current were also achieved.Analysis suggests that the ruled curved contact has strong application potentiality because of its low arc energy,low arc voltage noise and arc voltage peak,light ablation on the surface of the anode contact and high interrupting capacity.     

重离子径迹模板中组装半导体CdS一维纳米材料

用重离子辐照的聚碳酸酯为模板,采用电化学沉积法制备了半导体CdS纳米线和纳米管.通过选用不同蚀刻时间的模板,得到了直径20～100 nm、长度20～30 μm范围、粗细均匀且具有纤维锌矿结构的CdS纳米线与纳米管.利用扫描电子显微镜(SEM)、X射线衍射(XRD)和透射电子显微镜(TEM)对CdS纳米线与管的形貌和晶体结构特征进行了表征.     

低能氮离子注入香菇生物学效应的研究

本文用能量为 15 keV,而注量不同的氮离子注入对武香一号香菇进行诱变,分析了不同注量下菌丝长速,菌丝生物量以及多糖含量的变化,对该低能离子与微生物间的作用规律进行了初步探索,为进一步筛选出多糖高产菌株提供前提.实验结果表明菌丝长速,菌丝生物量及多糖含量随不同注量的变化情况基本遵循"马鞍型曲线".注量小时菌丝日均长速较快,随着注量的增大,菌丝日均长速呈下降趋势,但在1.5×1016cm-2附近,菌丝长速有短暂回升.在注量较小时,随着注量的增加,菌丝生物量及多糖含量先升高后降低,注量为4×1015cm-2时,两者均达到最大值,而后会出现小的波动,注量增加到1.5×1016cm-2时,菌丝生物量及多糖含量又会达到-个较大的峰值.通过发酵动力学分析,研究了香菇液体菌种培养过程中菌丝球数量及形态、摇瓶总重、pH值、多糖含量等指标的变化情况,绘制该菌发酵产糖的过程曲线,这将为诱变前后液体发酵过程的控制提供参数.     

放疗后早期肿瘤组织内99Tcm-rh-Annexin Ⅴ分布与Survivin、Caspase-3蛋白表达的相关性研究

采用99Tcm-rh-AnnexinⅤ作为核素凋亡显像示踪剂,观察小鼠放疗后早期肿瘤组织内Survivin、Caspase-3蛋白表达。结果显示,放疗组肿瘤组织内99Tcm-rh-AnnexinⅤ分布、TUNEL检测阳性细胞数及Caspase-3蛋白表达均明显多于对照组,Survivin蛋白表达A组明显高于B组,差异均存在显著性（P均<0.01）。相关性研究表明,肿瘤组织的放射性摄取与TUNEL阳性细胞数呈明显正相关（r=0.942,P=0.000）;肿瘤组织内Survivin蛋白表达与Caspase-3蛋白表达呈明显负相关（r=-0.836,P=0.000）。肿瘤组织内99Tcm-Annexin Ⅴ分布与Caspase-3蛋白表达呈明显正相关（r=0.948,P=0.000）,与Survivin蛋白表达呈明显负相关（r=-0.819,P<0.01）。以上结果提示,肿瘤组织内99Tcm-rh-AnnexinⅤ的分布可以反映放疗后早期肿瘤组织细胞凋亡的状况以及凋亡调控蛋白Survivin、Caspase-3表达水平的变化。     

三代核电自主化依托项目的工程建造管理模式

2007年7月24日,国家核电技术公司、三门核电有限公司、山东核电有限公司、中国技术进出口总公司,与美国西屋联合体及分包商分别签订了第三代核电自主化依托项目4个机组的核岛设计及部分主设备采购合同;国家核电技术     

国外最新消息

伊朗总统宣布已开始安装6000台新离心机伊朗总统艾哈迈迪·内贾德2008年4月8日宣布,伊朗已开始在纳坦兹铀浓缩基地安装6000台新的离心机。(编译自法新社2008年4月8日报道)     

不断变化、充满挑战的景象

无论在贫国还是在富国,能源问题都是一个快速上升的政治问题。油价已超过100美元一桶。全球变暖归因到煤及其他化石燃料。生物燃料受到更加密切的关注,包括对粮食生产和供应的影响。核能再一次接受人们的辩论。     

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民意测验表明,与几年前相比,英国公众离接受新建核电站更近了。然而,这种支持依然很脆弱。核能在英国的声望在21世纪的头几年和现在有了很大的提高,除了顽固反对核能的少数派外,公众普遍接受新建核电站,以迎接能源安全和气候变化的双重挑战,但是新建核电站的这种必要性要以合适的方式向公众提出。核工业一路走     

全国核与辐射设施退役学术研讨会简介

在国家政府有关部门及中核集团公司支持下,由中国核学会辐射防护分会会同相关学会于2007年11月5日至10日在四川绵阳召开了全国核与辐射设施退役学术研讨会.     

Continuous compositional spread investigation of SiC-based thin films prepared by MW-ECR plasma enhanced magnetron co-sputtering

A kind of combinatorial material methodology,also known as continuous compositional spread method,was employed to investigate the relationship between the optical band gap and composition of SiC thin films.A wide range of SixCy thin films with different carbon contents have been successfully deposited in a single deposition by carefully arranging the sample position on the substrate holder.The films were characterized by surface profiler,x-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy,fourier transform infrared spectroscopy and Raman spectroscopy.The carbon content y increases linearly from 0.28 to 0.72 while the sample position changed from 85 to 175 mm,the optical band gap changed between 1.27 and 1.99 eV,the maximum value corresponded to the stoichiometric SiC sample at the position of 130 mm,which has the highest Si?C bond density of 11.7×10^22 cm^-3.The C poor and C rich SixCy samples with y value less and larger than 0.5 were obtained while samples deviated from the position 130 mm,the optical band gap decreased with the Si?C bond density.     

Three dimensional nonlinear shock waves in inhomogeneous plasmas with different size dust grains and external magnetized field

The evolution of three dimensional nonlinear shock waves is investigated in a dusty plasma with inhomogeneous particles’density,nonadiabatic dust charge variation,external magnetized field and power law dust size distribution.For this purpose,a modified nonlinear Korteweg-de Vries Burgers equation containing variable coefficients is obtained by reductive perturbation method.The effects of inhomogeneity,dust size distribution,external magnetized field,dust charge variation and obliqueness parameter on shock structures are numerically examined in great detail.Furthermore,research results show that oscillatory shock waves and monotone shock waves exist and transform each other in this system.     

Guest Editorial:Special Section on the Second China-Japan Academic Symposium on Nuclear Fuel Cycle(ASNFC-2013)

<正>Shanghai,China,November 27-30,2013As a high-density energy with almost no discharge of greenhouse gas,nuclear energy plays an important role in long-term energy security and global warming prevention.However,to realize a sustainable development of nuclear energy for the future,it is necessary to save uranium resource and minimize radioactive waste.Advanced nuclear fuel     

法国核电未来的出路:对外出口

[英国《国际核工程》网站2010年12月8日报道]在法国电力公司(EDF)和阿海珐集团(Areva)组成的联盟在2009年阿联酋核电项目竞标中败北后,法国总统萨科奇下令组建了一个以法电前总裁     

PLASMA SCIENCE AND TECHNOLOGY AUTHOR INDEX TO VOLUME 18,NOS.1-4(2016)

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巴基斯坦将再建2台核电机组

【加拿大原子能公司网站2006年3月27日报道】5家世界一流的核技术与工程公司签订了一份为期4年的合同,共同组建“CANDU联盟”(Team CANDU),以便为在安大略新建核电机组提供交钥匙服务和有竞争力的解决方案。CANDU联盟的成员包括:加拿大原子能公司(AECL)、加拿大巴布科克与威尔科克斯公司(B&W)、加拿大通用电气公司(GEC)、加拿大日立有限公司(HCL)和SNC-兰万灵核工程公司(SLN)。安大略省电力局(OPA)2005年12月发布的一份报告显示,2/3的安大略基荷装机容量需要在未来15年内更换。CANDU联盟是一项战略结盟,为安大略省提供一种…     

Evaluation of NBI absorption and fast ion stored energy to improve thermal energy confinement time calculation in EAST

The absorption of neutral beam power and the fast ion stored energy in EAST plasmas with neutral beam injection(NBI)is analyzed to improve the calculation of thermal energy confinement time.The neutral beam power absorption and fast ion stored energy are systematically calculated using the TRANSP code,through the investigation of global parameters including plasma current,line averaged density and beam energy.Results have shown that scaling laws for the NBI absorption coefficient and fast ion energy rate are obtained through statistical analysis.A comparison of the confinement improvement factor H98y2 with these new scaling laws against those assuming fixed coefficients is given.     

Nuclear Fusion Within Extremely Dense Plasma Enhanced by Quantum Particle Waves

Quantum effects play an enhancement role in p-p chain reactions occurring within stars.Such an enhancement is quantified by a wave penetration factor that is proportional to the density of the participating fuel particles.This leads to an innovative theory for dense plasma,and its result shows good agreement with independent data derived from the solar energy output.An analysis of the first Z-pinch machine in mankind’s history exhibiting neutron emission leads to a derived deuterium plasma beam density greater than that of water,with plasma velocities exceeding 10000 km/s.Fusion power could be achieved by the intersection of four such pinched plasma beams with powerful head-on collisions in their common focal region due to the beam and target enhanced reaction.     

西伯利亚化学联合体将集中俄罗斯所有的铀转化产能

正【俄罗斯西伯利亚化学联合体网站2014年1月20日报道】在2013年第二季度,安加尔斯克(Angarsk)电化学厂关闭了六氟化铀生产线,并将其生产线转到西伯利亚(Siberian)化学联合体。这样,西伯利亚化学联合体将成为俄罗斯最大的铀转化基地。之前有报道说,俄罗斯国家原子能集团公司(Rosatom)计划将西伯利亚化学联合体