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121.
122.
Material effect of inner-detectors on the performances of the BESⅢ Electromagnetic Calorimeter (EMC) is investigated. The BESⅢ Time-Of-Flight counters (TOF) have been utilized to improve the energy resolution and detection efficiency for photons after a careful energy calibration. A matching algorithm between TOF and EMC energy deposits is developed, and the effects of beam-related background are discussed. The energy resolution is improved and the photon detection efficiency can be increased by the combined measurement of EMC and TOF detectors. 相似文献
123.
HE Miao WANG Yi-Fang BIAN Jian-Ming CAO Guo-Fu DENG Zi-Yan HE Kang-Lin HUANG Bin JI Xiao-Bin LI Gang LI Hai-Bo LI Wei-Dong LIU Chun-Xiu LIU Huai-Min MA Qiu-Mei MA Xiang MAO Ya-Jun MAO Ze-Pu MO Xiao-Hu QIU Jin-Fa SUN Sheng-Sen SUN Yong-Zhao WANG Ji-Ke WANG Liang-Liang WEN Shuo-Pin WU Ling-Hui XIE Yu-Guang YANG Ming YOU Zheng-Yun YU Guo-Wei YUAN Chang-Zheng YUAN Ye ZANG Shi-Lei ZHANG Chang-Chun ZHANG Jian-Yong ZHANG Ling ZHANG Xue-Yao ZHANG Yao ZHENG Zhi-Peng ZHU Yong-Sheng ZOU Jia-Heng 《中国物理C(英文版)》2008,32(4)
Material effect of inner-detectors on the performances of the BESⅢ Electromagnetic Calorimeter (EMC)is investigated.The BESⅢ Time-Of-Flight counters(TOF)have been utilized to improve the energy resolution and detection efficiency for photons after a careful energy calibration.A matching algorithm between TOF and EMC energy deposits is developed,and the effects of beam-related background are discussed.The energy resolution is improved and the photon detection efficiency can be increased by the combined measurement of EMC and TOF detectors. 相似文献
124.
孙永昭 何康林 李卫东 边渐明 曹国富 邓子艳 何苗 黄彬 季晓斌 李刚 李海波 刘春秀 刘怀民 马秋梅 马想 冒亚军 毛泽普 莫晓虎 邱进发 孙胜森 王纪科 王亮亮 文硕频 伍灵慧 谢宇广 杨明 尤郑昀 俞国威 苑长征 袁野 臧石磊 张长春 张建勇 张令 张学尧 张瑶 郑志鹏 朱永生 邹佳恒 《中国物理 C》2007,(5)
在ψ(3770)处,D0→K-π+是研究D0-■混合的非常理想的衰变道.实验上,良好的K/π识别技术将对寻找D0-■混合过程起着决定性的作用.在BESⅢ实验的物理预研究中,发现利用飞行时间的信息,能够精确测定末态中含有多条带电径迹事例的起始时间,从而可以改善飞行时间计数器的时间分辨率.进一步的研究表明,应用该方法后,BESⅢ双层TOF的时间分辨率从~78ps降到~64ps.按照20fb-1的ψ(3770)数据量进行估算,在95%置信度下,D0-■混合率的上限值可以提高7%左右. 相似文献
125.
126.
We have synthesized a ferrocene-based 1,3-alternate thiacalix[4]arene ditopic receptor 3 that contains four identical polyether arms terminated with the ferrocene amide moieties. Our studies have revealed that this redox-active receptor can be used as an electrochemical sensor to recognize both europium (Eu3+) and dihydrogen phosphate ions with a high selectivity. 相似文献
127.
The introduction of fluorine atoms into organic molecules is an attractive but challenging topic. In this work, an interesting palladium-catalyzed difluoroalkylative carbonylation of aryl olefins has been developed. A wide range of aryl olefins were transformed into the corresponding difluoropentanedioate compounds with good functional-group tolerance and excellent regioselectivity. Inexpensive ethyl bromodifluoroacetate acts both as a difluoroalkyl precursor and a nucleophile here. Additionally, a scale–up reaction was also performed successfully, and further transformations of the obtained product were shown as well.An interesting palladium-catalyzed difluoroalkylative carbonylation of aryl olefins has been developed. A wide range of aryl olefins were transformed into the corresponding difluoropentanedioate compounds with good functional-group tolerance and excellent regioselectivity. 相似文献
128.
YOU Ke ZHU Yu-Can LV Jun-Guang SUN Han-Sheng TIAN Wei-Hua ZHAO Wen-Heng ZHENG Zhi-Peng YE Ming-Han QING Cheng-Rui HE Zuo-Xiu CUI Feng-Zhu YU Chang-Jiang 《中国物理C(英文版)》1991,15(11):966-972
A search for the neutrinoless double beta decay of 48Ca is carried out in a coal mine which is located 512m underground near Beijing.Large scintillation crystals of natural CaF2 were used as both the detector and the double beta decay source.Result obtained after a total of 7588.5 hours of data taking gives 1.1×1022 years (68%C.L.) as the lower limit of the half-life of the neutrinoless double beta decay of 68Ca. 相似文献
129.
In order to describe the time delay in the surface roughing process the Kardar-Parisis-Zhang (KPZ) equation with memory effects is constructed and analysed using the dynamic renormalization group and the power counting mode coupling approach by Chattopadhyay [2009 Phys. Rev. E 80 011144]. In this paper, the scaling analysis and the classical self-consistent mode-coupling approximation are utilized to investigate the dynamic scaling behaviour of the KPZ equation with memory effects. The values of the scaling exponents depending on the memory parameter are calculated for the substrate dimensions being 1 and 2, respectively. The more detailed relationship between the scaling exponent and memory parameter reveals the significant influence of memory effects on the scaling properties of the KPZ equation. 相似文献
130.
We study the temperature T and the phase of the Josephson critical current I(Ф) by taking into account the roughness scattering effect at inerface in an f-wave superconductor (S)/Insulator layer (I)/f-wave superconductor (S) junction. It is found that the Josephson critical currents in f-wave Sir-wave S, the barrier strength and the roughness strength at inerface always suppress the Andreev reflection. When α=β, the phase dependence of the Josephson current I(Ф) between two f-wave S is predicted to be sin Ф; particularly, when a α≠ β, the phase dependence of the Josephson current I(Ф) between two f-wave superconductors is not predicted to be sin Ф and with the barrier strength increasing, the period of the I(Ф) turns decrease. 相似文献