分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Angle-resolved photoemission spectra (ARPES) are calculated in the Hubbard model by using cluster perturbation method. It is found that in a cluster of 12 sites, the local density of states displays the phase transition from normal conductor to Mott insulator with the increase of the electron-electron coupling. We show that a pseudogap develops from the metallic phase to the insulating phase. Evidence of spin-charge separation is also verified in the calculated single particle spectral functions.
分类: 核科学技术 >> 裂变堆工程技术 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: In a molten salt reactor (MSR), the fuel is dissolved in fluoride salt. In this paper, the reactivity worth and reactivity initiated transient of Molten-Salt Reactor Experiment (MSRE) in the control rod failure events are analyzed. The point kinetic coupling heat-transfer model with decay character of six-group delayed neutron precursors due to the fuel motion is applied. The relative power and temperature transient under reactivity step and ramp initiated at different power levels are studied. The results show that the reactor power and temperature increase to a maximum, where they begin to decrease to stable values. Comparing with full power level, the transient result at low power level is more serious. The results are of help in our study on safety characteristics of an MSR system.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Different channel lengths and layouts on 0.18 m NMOS transistors are designed for investigating the dependence of short channel effects (SCEs) on the width of shallow trench isolation (STI) devices and designing in radiation hardness. Results show that, prior to irradiation, the devices exhibited nearideal IV characteristics, with no significant SCEs. Following irradiation, no noticeable shift of threshold voltage is observed, radiationinduced edgeleakage current, however, exhibits significant sensitivity on TID. Moreover, radiationenhanced drain induced barrier lowering (DIBL) and channel length modulation (CLM) effects are observed on shortchannel NMOS transistors. Comparing to stripegate layout, enclosedgate layout has excellent radiation tolerance.
分类: 化学 >> 物理化学 提交时间: 2017-11-05 合作期刊: 《结构化学》
摘要: A novel coordination complex, {[Cd2(C20H10O5)2(H2O)4]·10H2O}n, has been synthesized based on fluorescein (2-(6-hydroxy-3-oxo-3H-xanthen-9-yl) benzoic acid) and systematically characterized by elemental analysis, infrared (IR) spectrum, thermo gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P2/n with a = 20.428(5), b = 8.084(2), c = 21.689(5) Å, β = 96.360(5)º, Mr = 993.46, V = 3559.7(15) Å3, Z = 4, Dx = 1.845 g/cm3, μ = 1.276 mm-1, F(000) = 1974.0, GOOF = 1.044, λ(MoKα) = 0.71073 Å, the final R = 0.0553 and wR = 0.1720 for 7245 observed reflections with I > 2σ(I).
分类: 物理学 >> 核物理学 提交时间: 2016-08-30
摘要: WIMPs are a well-motivated galactic dark matter candidate. Liquid argon (LAr) is an attractive target for the direct detection of WIMPs. The LAr prototype detector is designed to study the technology and property of LAr detector. The prototype detector have an active volume containing 0.65 kg of liquid argon. The liquid nitrogen(LN) cooling system allows the temperature of liquid argon to be maintained at the boiling point (87.8 K) with fluctuations less than 0.1 K. The prototype was calibrated with a Na22 source, with the light yield 1.591�.019 p.e./keV for the 511 keV gamma rays using the domestic-made argon purification system.