大功率LED热管散热器的热设计研究

给出了一种应用于大功率LED散热的新型热管翅片散热器,该散热器能够有效利用自然风和垂直对流,建立了散热器结构模型,采用Icepak软件分析了散热器参数对大功率LED芯片结温的影响规律.结果表明,热管导热系数、直径以及自然风风速对芯片结温有显著影响,芯片结温随热管导热系数、直径以及自然风风速的增加而降低,翅片导热系数和表...     

CRITICAL CURRENT DENSITY OF Y-Ba-Cu-Sn-O SUPERCONDUCTORS

The magnetic curves of bulk Y-Ba-Cu-Sn-O have been studied in the temperature range 60-77K and in fields up to 2.4T. The results indicate that J_c varies with the magnetic field as a power law and decreases exponentially with temperature. The critical current density J_c can be improved by the substitution of Sn for Cu.