∧c^＊ in a coupled-channel baryon-meson scattering

Possible structures and properties of some excited states of Λ_c⁺ dynamically generated in the coupled-channel P-wave meson-baryon scattering are studied by solving the Bethe-Salpeter(BS) equation in the framework of the Chiral Unitary Approach. It is shown that both Λ_c⁺(2765) and Λ_c⁺(2940) could be generated dynamically and could be compound states with multi-configuration molecular-like structures. The couplings of the generated states to various reaction channels are also calculated. Moreover, two highly excited states, Λ_c⁺(3024) and Λ_c⁺(3134), are predicted.     

Design studies on the 4π γ-ray calorimeter for the ETF experiment at HIRFL-CSR

A high detection efficiency calorimeter which is used to detect γ-rays with energies from 1 MeV up to 10 MeV as well as light charged particles has been proposed. Design of the geometry, results of the crystal tests and Monte Carlo simulations are presented in this paper. The simulation results confirm that the calorimeter can obtain high detection efficiency and good energy resolution with the current designed geometry. And the calorimeter is competent for the future External Target Facility (ETF) experiments.     

Radiation induced inter-device leakage degradation

The evolution of inter-device leakage current with total ionizing dose in transistors in 180 nm generation technologies is studied with an N-type poly-gate field device (PFD) that uses the shallow trench isolation as an effective gate oxide. The overall radiation response of these structures is determined by the trapped charge in the oxide. The impacts of different bias conditions during irradiation on the inter-device leakage current are studied for the first time in this work, which demonstrates that the worst condition is the same as traditional NMOS transistors. Moreover, the two-dimensional technology computer-aided design simulation is used to understand the bias dependence.     

基于(u,p)方程含多孔材料有源声学结构的声学性能研究

为准确分析含多孔材料有源声学结构的声学性能,利用一种结合(u,p)方程和有限元技术的计算方法对有源声学结构建模,分析声波在多孔材料中传播规律,并进行了实验验证.基于固相位移和流相声压的(u,p)方程对多孔材料固、流两相间强烈耦合进行分析,建立了多孔材料的有限元模型,并对含有多孔材料双层板有源声学结构的声学性能进行了测量...     

脉冲激光在镀层圆柱表面激发的表面波

分别从理论和实验上研究了脉冲激光在快、慢镀层圆柱表面激发的表面波声场.脉冲激光线源在镀层圆柱周向上激发超声波信号并利用激光干涉仪检测.对钢基底锌镀层圆柱和锡基底铜镀层圆柱试样表面波的理论频散和实验信号估计频散进行了比较,瞬态位移场则利用留数定理与FFT技术数值仿真得到并与实验波形进行对比.结果显示:理论频散和仿真波形与...     

金纳米棒核/贵金属壳杂化纳米结构的可控制备和性质调控

贵金属纳米颗粒由于其独特的光学及催化性能引起了人们的广泛关注,而这些性能与纳米颗粒的尺寸、形貌、结构组成等密切相关.目前如何有意识地控制晶体生长过程,以得到人们需要的纳米结构和组成,仍具有相当大的挑战性.文章重点介绍了利用具有特定形貌和晶面组成的金纳米棒（Au nanorods）作为种子,借助形成核/壳结构,诱导了Ag...     

红色荧光粉NazCa1-x-2y-zBiyMoO4∶Eu3+x+y发光研究

采用高温固相法制备系列红色荧光粉Naz Ca1-x-2y-zBiyMoO4 ∶ Eu3+x+y (y,z=0,x=0.24,0.26,0.30,0.34,0.38; x=0.30,y=0.01,0.02,0.03,0.04,0.05,0.06,0.07,z=0; x=0.30,y=0.04,z=0.38).用X射线粉末衍射(XRD)法测试了所制样品晶相结构.采用荧光光谱仪对样品的发光性能进行了表征,结果表明:当Eu3+单掺杂量浓度x=0.30时,荧光粉(Ca0.70 MoO4∶Eu3+0.30)的发光强度最强;当Eu3+-Bi3+共掺杂量浓度y=0.03时,电荷迁移带(CTB)强度达到最强,而对于Eu3+特征发射峰,当共掺杂浓度y＜0.03时,位于393 nm处的激发峰强度比464 nm强,共掺浓度y＞0.03时,464 nm峰比393 nm峰强,共掺浓度为y=0.04时,393和464 nm处两峰位置强度都达到最强.作为电荷补尝剂的Na2 CO3掺入上述荧光粉中后,荧光粉激发和发射强度明显地增强.结果表明,通过调节Bi3+ /Eu3+掺杂比例可以改变位于近紫外光393 nm和蓝光区464 nm处激发光相对强度.