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k 《Solid-state electronics》2008,52(6):849-856
We present the hole subband structure calculation in single and double p-type δ-doped quantum wells in Si based on the 4×4 Luttinger–Kohn Hamiltonian. The valence band bending and the Γ hole states are calculated within the lines of the Thomas–Fermi–Dirac approximation and the effective mass theory at the Brillouin zone center. The obtained zone center eigenstates are then used to diagonalize the k·p Hamiltonian for non-zero k. The hole subband structure is analyzed as a function of the impurity density and the distance between δ wells. It is shown that the application of a 4×4 model to describe the hole ground state in single p-type δ-doped in Si can be misleading. 相似文献
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介绍TY2100A柴油机为提高动力性、可靠性所采取的改进设计与质量保证措施,以及实施这些措施后该型柴油机动力性与可靠性试验结果。 相似文献
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S.A. Nouh H. Amer 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(7):1129-1134
The effect of neutron dose on the structural properties of a Makrofol polycarbonate detector has been studied. Samples of Makrofol were classified into three main groups. The first, second and third groups were irradiated with neutrons in the dose ranges of 0.01-0.08, 0.1-0.8 and 1.0-8.0 Sv, respectively. The structural modifications in the neutron irradiated samples were studied using X-ray diffraction and Fourier-transform infrared spectroscopy. In addition, the effect of neutron dose on the intrinsic viscosity of the liquid samples, as a measure of the mean molecular mass of the Makrofol polymer, was studied. An increase in the -OH groups was observed at dose ranges of 0.01-0.04 and 3.21-8.0 Sv due to the degradation of carbonate group and the -H abstraction from the polymer backbone to form hydroxyl groups. This indicates that the degradation is dominant at these dose ranges that enhance the degree of ordering in the irradiated samples. On the other hand, irradiation in the dose range 0.04-3.21 Sv was characterized by a dominant crosslinking mechanism that led to an increase of the amorphous phase and average molecular mass. 相似文献
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随着我国煤炭事业的蓬勃发展,各种先进的煤矿采掘设备相继研制成功并投入使用,提高了安全系数,加快了掘进速度。该文重点介绍EBZ160TY型掘进机,在巷道掘进使用中取得的效果。 相似文献
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在立式中频感应淬火设备中对TY320单双边支重轮进行淬火处理改进工艺研究。结果表明,采用多次同时均匀加热然后冷却的方式,大大提高了TY320支重轮的硬度和淬硬层深度,提高生产率50%,降低了废品率和劳动强度。 相似文献
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多侧音测距广泛应用于USB统一测控系统中,载波及侧音跟踪状态对距离结果有重要影响。在距离捕获阶段,载波及侧音跟踪状态影响距离匹配结果,在距离跟踪阶段,载波或侧音失锁会造成距离结果跳周。结合多测距音测距原理对捕获阶段和跟踪阶段中出现的问题进行了深入分析,在测距过程中利用速度值对距离结果进行实时检测及递推的方法可以解决上述问题,并结合工程应用数据对问题解决方法进行了验证。 相似文献