M—矩阵的判定

本文引入了α－双对角占优的概念，进而给出了若干个判定Ｍ－矩阵的充分条件及充分必要条件。     

Investigation of the energy resolution with a RETGEM detector

A novel Micro-pattern gaseous detector （MPGD）, thick GEM with electrodes made of a resistive material （RETGEM） is presented. In this paper we mainly investigate the energy resolution of a RETGEM in Ar＋CO2 with different gas mixtures. The results indicate that an energy resolution 30% in single and double mode can be obtained. The existence of an optimum energy resolution is discussed.     

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针对准中性Vlasov-Poisson系统中多尺度物理参数共存的问题开展研究,采用渐近保持格式推导出与Vlasov方程相耦合的Poisson方程。数值模拟了一维等离子体在真空中的膨胀,比较了渐近保持PIC算法与传统PIC算法模拟结果的异同。结果表明：两种算法在满足多尺度中小尺度量限制的前提下,其结果保持高度一致;且在克服小尺度量束缚时,渐近保持PIC算法依然可以正确地模拟等离子体的物理行为,大大节省了计算时间。     

高电压锯齿波聚束器的设计研制

近些年来,使用锯齿波直接形成的方法建造非谐振型聚束器在国内及国际均得到了广泛的应用。由于电子技术及机械加工工艺的飞速发展和更高功率电子管的出现,可以设计出更高指标的聚束器,进而可以有效提高束线的匹配效率及运行稳定度。对兰州重离子加速器源束线新的高电压锯齿波聚束器的研制进行了详细阐述,由于该聚束器具有目前国际同类型设备中最高的电压、频率以及相对苛刻的现场条件限制,故还对设计中所涉及的工程实施方案进行了有效补充和完善。     

耦合界面计算格式的一维流体力学Lagrange有限点方法

为探索高维多介质流体力学散乱点集上的Lagrange有限点方法,首先对相应一维问题进行研究,提出一种Lagrange有限点方法:在计算区域内(包括物质界面)设置任意离散点集,所有力学量都设在该点集上,在内点和界面点上分别建立离散格式.内点算法为基于Taylor展开的差分方法.界面点算法为显式追踪算法,从定解条件出发,利用Rankine-Hugoniot关系和特征差分方法,计算界面点位置及相应的状态量变化.通过追踪界面点的运动得到物质界面是方法的最大特色.典型算例计算结果与精确解符合很好,验证了算法的合理和有效性.     

An X-ray imaging device based on a GEM detector with delay-line readout

An X-ray imaging device based on a triple-GEM (Gas Electron Multiplier) detector, a fast delay-line circuit with 700 MHz cut-off frequency and two dimensional readout strips with 150 μm width on the top and 250 μm width on the bottom, is designed and tested. The localization information is derived from the propagation time of the induced signals on the readout strips. This device has a good spatial resolution of 150 μm and works stably at an intensity of 105 Hz/mm2 with 8 keV X-rays.     

Investigation of the energy resolution with a RETGEM detector

A novel Micro-pattern gaseous detector (MPGD), thick GEM with electrodes made of a resistive material (RETGEM) is presented. In this paper we mainly investigate the energy resolution of a RETGEM in Ar+CO_2 with different gas mixtures. The results indicate that an energy resolution 30% in single and double mode can be obtained. The existence of an optimum energy resolution is discussed.     

Development of a China test cryomodule for ILC

Research and development of a 1.3 GHz 9-cell cavity test cryomodule were carried out by a collaboration group between IHEP (Institute of High Energy Physics) and TIPC (Technical Institute of Physics and Chemistry) in China. The cryomodule is a "test model" for the ILC cryomodule, and a key component of a superconducting accelerator test unit which will be built in the near future, also can be used as a horizontal test facility for 1.3~GHz 9-cell cavities. This paper presents the development status of the cryomodule, including structure design, cryogenic flow diagram, thermal and mechanical simulations, heat load estimation and etc.     

ICP-AES测定氟化稀土中铝

采用高氯酸、盐酸分解样品,草酸将稀土沉淀分离,用ICP-AES快速测定氟化稀土中的铝,加标回收率达98%—102%,相对标准偏差＆lt;2.0%,此方法分析简单快速、结果准确可靠。     

创新研究型物理实验教学平台的建设与实践

实验教学中心在面向全校物理、材料科学、地空科学及生命科学类高年级本科生开设创新研究型实验课程中,创建了创新研究型物理实验教学平台,使学生自主设计课题,制定研究方案,选择相应的平台对该课题进行系统研究.通过三学年的建设与教学实践,表明该平台的建立不仅增强了学生实验动手机会,而且提高了学生自主分析问题、解决问题的能力,激发了学生的主观能动性、主动创造思维,培养了学生的创新能力.同时也促进了教师知识的更新和教学水平的提高.