共查询到20条相似文献,搜索用时 62 毫秒
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本文描述了北京谱仪BES主漂移室一个多层多单元模型的结构, 给出在日本KEK12GeV质子同步加速器K2试验束上, 利用动量0.5~1.5GeV/c的e+,π+和p束测量模型性能的主要结果. 在3.1cm的单元半宽内, 室的单丝空间分辨率σx=170~210μm. 相当四十次dE/dx取样的能量分辨率σE/E约为15%, 提供了北京谱仪工作能区鉴别粒子的一种有效方法, 可同飞行时间(TOF)计数器和簇射计数器相互补充. 相似文献
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环形正负电子对撞机(circular electron-positron collider, CEPC)通过d E/dx的测量进行长寿命带电粒子的鉴别,要求对d E/dx的测量达到约3%的精度.但d E/dx的测量对带电粒子π/K,π/P和K/P各有一个分辨盲区,对应的横动量分别为1 GeV/c, 1.6 GeV/c和2 GeV/c.一种解决方案是采用高精度飞行时间(time of flight, TOF)探测器填补分辨盲区,探测器系统的时间分辨要求小于50 ps.针对这一要求本文提出一种小颗粒飞行时间探测器,具体方案为采用小块塑料闪烁体(1 cm×1 cm×0.3 cm)侧面耦合硅光电倍增管读出.介绍了该探测器的构建以及利用90 Sr电子准直源和高速波形采集电子学对该探测器的性能标定.结果显示,采用恒比定时法,该探测器的时间分辨约为48 ps,可以满足CEPC对飞行时间探测器的要求. 相似文献
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从MonteCalor模拟和北京谱仪 (BESⅡ )所取的实验数据入手 ,分析了p和 p产生次级带电径迹和中性径迹的几率以及好径迹选择条件对这些次级径迹的去除情况、p在探测器中的能量损失和 p的湮没、p和 p在桶部簇射计数器中沉积能量的分布以及 3种不同的粒子鉴别方法的优劣 .给出了BES目前可以正确重建出的p和 p的动量的最小值和利用TOF和dE dx的联合信息鉴别p和 p的优越性 . 相似文献
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从Monte Calor模拟和北京谱仪(BESⅡ)所取的实验数据入手,分析了p和p产生次级带电径迹和中性径迹的几率以及好径迹选择条件对这些次级径迹的去除情况、p在探测器中的能量损失和p的湮没、p和p在桶部簇射计数器中沉积能量的分布以及3种不同的粒子鉴别方法的优劣.给出了BES目前可以正确重建出的p和p的动量的最小值和利用TOF和dE?dx的联合信息鉴别p和p的优越性. 相似文献
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In this study, an energy model based on the first law of thermodynamics is developed to evaluated energy efficiency and specific energy consumption. The influences of hot air temperature and initial weight of coffee beans on energy consumption are considered. Furthermore, a comparison between combined microwave–hot air spouted bed drying and hot air spouted bed drying methods on energy consumption is also investigated in detail. The results show that energy efficiency as well as energy consumption depends on hot air temperature, initial weight of coffee bean, and typical drying methods (combined microwave–hot air spouted bed and hot air spouted bed). The optimum drying condition is also achieved in this study. 相似文献
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B. A. Brusilovsky 《辐射效应与固体损伤》2013,168(3-4):303-306
The effect of polymorphous transitions on the temperature dependence of the number of ions scattered in a given direction has been studied for different scattering angles. 相似文献
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通过一个简单的具体问题,对内能和机械能之间的本质区别进行了解析,这对于深入理解热力学中的概念及其规律的本质是极有意义的。 相似文献
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The nuclear symmetry energy coefficient(including the coefficient a_(sym)~((4)) of the I~4 term) of finite nuclei is extracted by using the differences of available experimental binding energies of isobaric nuclei.It is found that the extracted symmetry energy coefficient a_(sym)~*(A,I) decreases with increasing isospin asymmetry I,which is mainly caused by Wigner correction,since e_(sym)~* is the summation of the traditional symmetry energy e_(sym) and the Wigner energy ew.We obtain the optimal values J = 30.25±0.10 MeV,a_(ss)=56.18±1.25 MeV,a_(sym)~((4)) = 8.33±1.21 MeV and the Wigner parameter x= 2.38 ±0.12 through a polynomial fit to 2240 measured binding energies for nuclei with20 ≤ A ≤ 261 with an rms deviation of 23.42 keV.We also find that the volume symmetry coefficient J■ 30 MeV is insensitive to the value x,whereas the surface symmetry coefficient a_(ss) and the coefficient a_(sym)~((4)) are very sensitive to the value of x in the range 1≤x≤4.The contribution of the a_(sym)~((4)) term increases rapidly with increasing isospin asymmetry I.For very neutron-rich nuclei,the contribution of the a_(sym)~((4)) term will play an important role. 相似文献
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Chenyixuan Ni Xiaodai Xue Shengwei Mei Xiao-Ping Zhang Xiaotao Chen 《Entropy (Basel, Switzerland)》2020,22(12)
As a fundamental infrastructure of energy supply for future society, energy Internet (EI) can achieve clean energy generation, conversion, storage and consumption in a more economic and safer way. This paper demonstrates the technology principle of advanced adiabatic compressed air energy storage system (AA-CAES), as well as analysis of the technical characteristics of AA-CAES. Furthermore, we propose an overall architectural scheme of a clean energy router (CER) based on AA-CAES. The storage and mutual conversion mechanism of wind and solar power, heating, and other clean energy were designed to provide a key technological solution for the coordination and comprehensive utilization of various clean energies for the EI. Therefore, the design of the CER scheme and its efficiency were analyzed based on a thermodynamic simulation model of AA-CAES. Meanwhile, we explored the energy conversion mechanism of the CER and improved its overall efficiency. The CER based on AA-CAES proposed in this paper can provide a reference for efficient comprehensive energy utilization (CEU) (93.6%) in regions with abundant wind and solar energy sources. 相似文献
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Summary A method is given to calculate the maximum compositional gradient in single crystals, grown by unidirectional solidification,
of binary or pseudobinary materials. The calculation is based on the data obtained from the phase diagrams. Compositional
gradients of HgTe-CdTe and PbTe-SnTe systems along the growth axis are shown. 相似文献