C_(60)薄膜的离子注入损伤研究

在２００ｋｅＶ重离子加速器上，用１２０—３６０ｋｅＶ的Ｈ，Ｎ，Ａｒ和Ｍｏ离子注入Ｃ６０薄膜．对注入后薄膜的拉曼谱进行了分析．结果表明，不同离子注入Ｃ６０薄膜后，Ｃ６０的１４６９ｃｍ－１特征峰随注入剂量的增加均呈指数式下降，同时在１３００—１７００ｃｍ－１范围出现非晶碳峰，并逐渐增强，最终完全非晶化．而且１４６９ｃｍ－１拉曼峰的强度及Ｃ６０薄膜完全非晶化所对应的剂量与注入离子的种类和能量有关．进一步的分析表明，Ｃ６０分子的损伤主要是由注入离子的核能量转移所造成，与电子能量转移无关．Ｈ离子注入Ｃ６０薄膜后，１４６９ｃｍ－１处特征拉曼峰向短波方向非对称展宽，这可能是注入的Ｈ离子通过电子能量转移使Ｃ６０分子发生聚合的结果The C 60 films have been implanted with 120—360keV H,N, Ar and Mo ions by using a 200keV heavy ion accelerator. The samples were investigated by Raman spectra. The results showed an exponential decrease of intensity for 1469cm -1 line depending on the kind of ions and dose. There appeared a structural transformation of C 60 to amorphous carbon at certain doses, which is correlated to the nuclear energy transfer. H ions implantation resulted in an asymmetrical broadening of 1469cm ...北京市自然科学基金,北京市跨世纪人才工程专项基

离子注入对C_(60)薄膜结构的影响

利用高能离子注入技术系统地研究了不同剂量、不同种类离子注入对Ｃ６０薄膜结构的影响，并利用Ｒａｍａｎ光谱对其结构进行分析．结果表明：中等能量的离子注入会影响Ｃ６０薄膜的结构，使Ｃ６０分子薄膜产生聚合和非晶碳化现象，但上述现象的出现与注入离子的剂量大小有关，并存在一注量阈值，只有在此阈值之上，Ｃ６０薄膜结构才发生改变，研究表明这与注入离子同Ｃ６０分子之间互作用方式有关C 60 films were irradiatied at room temperature by medium energy(120 360keV) radiation of different ions (H +,He +,N +,Ar +), and the radiation effects were investigated using Raman spectra. The results showed that the radiation of medium energy ions could cause C 60 films polymerized and amorphous. However, occurrence of the phenomena depends on dosage, which is related to the interaction between the radiation ion and C 60 molecule. A possible explanation for th..

生活事件、性格对某些心身疾病的影响的调查分析

本文用生活事件经历调查表(LEES)对278名心身疾病者,282名癌症患者和 273名健康人(对照组)作调查。结果表明:心身疾病和癌症患者病前出现应激性事件的频度(人次),及对事件产生负性情绪体验的强度(得分)皆明显高于对照组。在应激性生活事件中,家庭事件因素的频度和强度均较高,从某种意义上说,它可能是心身疾病和癌症的重要前因之一。生活事件强度体验与个体个性特征、应付策略和社会支持有关。</p

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies