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澳大利亚科学家发明“印制”激光技术,让便携超薄电视、可折叠电子报纸不再遥不可及。传统激光昂贵且不能印刷于介质,最近澳大利亚墨尔本大学和意大利帕多瓦大学的研究人员利用“量子点”(半导体材料的纳米晶体),终于开发出价格不贵、可以印刷的激光。 相似文献
993.
<正>一组研究人员利用高能激光束引爆了一个小塑料球,创造了类似于在黑洞外围所发现的情况。这一研究上的进展可以使科学家们对极端环境中物质和能量的性 相似文献
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Optical Properties of Zinc-Blende InGaN/GaN Quantum Well Structures and Comparison with Experiment 下载免费PDF全文
Optical properties of zinc-blende InGaN/GaN Q W structures are investigated using the multiband effective-mass theory. The transition wavelength values at 300 K ranged from 440 to 570nm in the investigated range of the In composition and the well width. The theoretical wavelengths show reasonable agreement with the experimental results. The optical gain decreases with the increasing well width. This is mainly due to the reduction in the quasi-Fermi-level separation because the optical matrix element increases with the well width. 相似文献
999.
Numerical Study on Open-Circuit Voltage of Single Layer Organic Solar Cells with Schottky Contacts: Effects of Molecular Energy Levels, Temperature and Thickness 下载免费PDF全文
We numerically investigate the effects of the exciton generation rate G, temperature T, the active layer thickness d and the position of LUMO level EL related to the cathode work function Wc at a given energy gap on the opencircuit voltage Voc of single layer organic solar cells with Schottky contact. It is demonstrated that open-circuit voltage increases concomitantly with the decreasing cathode work function Wc for given anode work functions and exciton generation rates. In the case of given cathode and anode work functions, the open-circuit voltage first increases with the exciton generation rate and then reaches a saturation value, which equals to the builtin voltage. Additionally, it is worth noting that a significant improvement to Voc could be made by selecting an organic material which has a relative high LUMO level (low |EL| value). However, Voc decreases as the temperature increases, and the decreasing rate reduces with the enhancement of exeiton generation rate. Our study also shows that it is of no benefit to improve the open-circuit voltage by increasing the device thickness because of an enhanced charge recombination in thicker devices. 相似文献
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Numerical Investigation on Inviscid Instability of Streaky Structures in Incompressible Boundary Layer Flow 下载免费PDF全文
Numerical investigation is made on the effect of streaky structures in transition by inviscid linear disturbance equation with temporal mode. Several disturbances with different streamwise wave numbers were induced, and the evolutions with time step were received. It suggests that the exponential growth and periodic variation of the waves are in existence. As the streamwise wave number increases, the disturbance growth rate begins by increasing, reaches a maximum at around α=0.4 with a disturbance frequency of 0.2186 + 0.001457i, and then decreases. Furthermore, the eigenfunctions of pressure disturbance are plotted. 相似文献