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AMS ^(10)Be测量本底研究和改进 被引量:2
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作者 naveed ali 付东坡 +4 位作者 朱正 蒋正元 丁杏芳 周力平 刘克新 《原子能科学技术》 EI CAS CSCD 北大核心 2008年第B09期246-250,共5页
10Be是加速器质谱(AMS)测量中重要性仅次于14C的核素,在第四纪地质研究等方面发挥着重要作用。为开展岩石暴露年龄测定和黄土中10Be含量测量等应用研究,北京大学加速器质谱(PKUAMS)在设备改进的基础上对10Be测量本底进行了较为系统的研... 10Be是加速器质谱(AMS)测量中重要性仅次于14C的核素,在第四纪地质研究等方面发挥着重要作用。为开展岩石暴露年龄测定和黄土中10Be含量测量等应用研究,北京大学加速器质谱(PKUAMS)在设备改进的基础上对10Be测量本底进行了较为系统的研究,使测量本底达到了6×10-15。本工作主要介绍AMS10Be测量本底的主要来源,从提高10Be离子计数率与抑制7Be干扰本底两个方面对10Be测量本底进行了较为系统的研究与改进。 展开更多
关键词 AMS 10Be测量 本底 计数率
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H^+,N^+和Ar^+离子束辐射诱导碳纳米结构的变化(英文) 被引量:2
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作者 A Ishaq Shahid Iqbal +6 位作者 naveed ali A A Khurram A U Akrajas C F Dee Shahzad Naseem H M Rafique Yan Long 《新型炭材料》 SCIE EI CAS CSCD 北大核心 2013年第2期81-87,共7页
在室温和高温下,以不同辐射剂量的H+、N+和Ar+离子辐照多壁碳纳米管和无定形碳纳米线。利用透射电镜和拉曼光谱研究多壁碳纳米管和无定形碳纳米线的结构变化及损伤。以70keV N+离子束辐射多壁碳纳米管在室温下可形成无定形碳纳米线。10... 在室温和高温下,以不同辐射剂量的H+、N+和Ar+离子辐照多壁碳纳米管和无定形碳纳米线。利用透射电镜和拉曼光谱研究多壁碳纳米管和无定形碳纳米线的结构变化及损伤。以70keV N+离子束辐射多壁碳纳米管在室温下可形成无定形碳纳米线。1000K下70keV的H+离子束照射导致无定形碳纳米线向金刚石结构转变。离子辐照多壁碳纳米管的有序程度足够高,70keV的N+和Ar+离子能够引起碳从多壁碳纳米管的剥落。离子辐射能够为缺陷的转化提供必需的动力学驱动力。 展开更多
关键词 多壁碳纳米管 离子束辐射 相转变 无定形碳纳米线 洋葱状碳
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Comparison of Mechanical Properties of Acid and UV Ozone Treated Nanodiamond Epoxy Nanocomposites
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作者 Sobia A.Rakha naveed ali +3 位作者 Yasir A.Haleem Fakhre Alam Aqeel A.Khurram Arshad Munir 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2014年第8期753-758,共6页
Nanodiamond(ND) powder was successfully activated by wet chemical method and by exposure of UV/O3 in a chamber followed by mixing in triethylenetetramine(TETA) solution.The reinforcement role of activated ND in th... Nanodiamond(ND) powder was successfully activated by wet chemical method and by exposure of UV/O3 in a chamber followed by mixing in triethylenetetramine(TETA) solution.The reinforcement role of activated ND in the mechanical properties of epoxy matrix was studied.Both treatments,i.e.acid and UV/O3 provide ND surface with chemical functionalities for adhesion with epoxy resin.Fourier transform infrared spectroscopy was utilized to confirm the attachment of surface groups to the ND particles.The low content of acid and UV/O3 activated ND was dispersed ultrasonically in the epoxy matrix separately to make nanocomposites.The mechanical properties of the nanocomposites were investigated under three point bending.The strong interactions among activated ND particles and the epoxy resin provide efficient load transfer interfaces,which enhances the mechanical properties of the composites.It was found that the flexural strength,modulus,and toughness of 0.1 wt%ND loaded nanocomposites have been enhanced up to 85%,57%,and 39%,respectively for UV/O3 treated ND powder.It is also found that the optimum ND concentration to achieve maximum reinforcement is 0.1 wt%while higher concentrations lead to decrease in mechanical properties.The significant improvement of the mechanical properties of the ND/epoxy nanocomposites is attributed to the good dispersion of the functionalized ND in epoxy matrix. 展开更多
关键词 NANODIAMOND DISPERSION Mechanical properties NANOCOMPOSITES
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