988 resultados para Crenne, Hélisenne de, époque 1538-1541


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We report the structural and optical characteristics of InAs quantum dots (QDs) grown on GaAs (311)A substrates. Atomic force microscopic result shows that QDs on (311)A surface exhibit a nonconventional, faceted, arrowhead-like shapes aligned in the [233] direction. The photoluminescence (PL) intensity, peak position and the full width at half maxinum (FWHM) are all closely related to the measurement temperature. The fast redshift of PL energy and monotonous decrease of linewidth with increasing temperature were observed and explained by carriers being thermally activated to the barrier produced by the wetting layer and then being retrapped and recombined in energetically lower-lying QDs states. This model explains our results well.

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于2010-11-23批量导入

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报道了Φ150mm CMOS硅外延材料的研究开发及集成电路应用成果,对Φ200mmP/P~-硅外延材料进行了初步探索研究。Φ150mm P/P~+硅外延片实现了批量生产,并成功应用于集成电路生产线,芯片成品率大于80%。硅外延片的参数指标能满足集成电路制造要求。

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于1905-07-02批量导入IMP-IR

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用47MeV/nucleon的12C离子轰击133Cs靶,产生许多种不同元素的同位素。利用经典的化学分离方法,从大量的Cs和其它反应产物混合物中分离出I、Ba和Ce等。使用离线γ谱学方法,完成I、Ba、Ce等样品的γ活性测量。根据每种元素不同同位素的特征γ射线峰的强度和丰度,对I、Ba和Ce等样品中杂质的含量进行分析。结果显示该流程对杂质元素去污的效果是满意的。

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利用同位旋相关的量子分子动力学模型 ,研究了中能重离子碰撞过程中的库仑相互作用对于动量耗散的同位旋效应 .计算结果表明 :由于库仑相互作用的存在 ,使得碰撞过程中的化学不稳定区和力学不稳定区减小 ,明显地减弱了动量耗散 ;其减弱的程度与对称势的形式及强度有关 ,对称势越强则动量耗散的减弱幅度越大 .动量耗散灵敏地依赖于核子 核子碰撞截面的同位旋相关性而较弱地依赖于对称势 ,这一特征不论有无库仑相互作用均存在 .

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The proton radioactivity half-lives of spherical proton emitters are investigated within a generalized liquid drop model (GLDM), including the proximity effects between nuclei in a neck and the mass and charge asymmetry. The penetrability is calculated in the WKB approximation and the assault frequency is estimated by the quantum mechanism method considering the structure of the parent nucleus. The spectroscopic factor is taken into account in half-life calculation, which is obtained by employing the relativistic mean field (RMF) theory. The half-lives within the GLDM are compared with the experimental data and other theoretical values. The results show that the GLDM works quite well for spherical proton emitters when the assault frequency is estimated by the quantum mechanical method and the spectroscopic factor is considered.

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利用长期定位试验研究了下辽河平原地区不同施肥处理下潮棕壤微生物量碳的变化。结果表明:不施肥处理的微生物量碳含量最低,化肥均衡施用和施用循环肥均能显著提高土壤微生物量碳含量(P<0.05),以化肥N、P、K+循环猪圈肥处理效果最好;各处理的微生物量碳均呈现出春冬季较低,夏秋季较高的趋势;化肥均衡施用配合循环肥能显著提高土壤微生物量碳的周转强度,缩短周转时间(P<0.05),以化肥N、P、K+循环猪圈肥处理土壤微生物量碳的周转时间最短,1年可周转1.03次。