排序方式: 共有38条查询结果,搜索用时 15 毫秒
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研究了高能短脉冲激光薄膜制备的整个烧蚀过程.首先建立了基于超热理论的烧蚀模型,然 后利用较为符合实际的高斯分布表示脉冲激光输入能量密度,给出了考虑蒸发效应不同阶段 的烧蚀状态方程.结合适当的边界条件,以Si靶材为例,利用有限差分法得到了靶材在各个 阶段温度随时间和烧蚀深度的演化分布规律及表面蒸发速度与烧蚀深度在不同激光辐照强度 下随时间的演化规律.结果表明,在脉冲激光辐照阶段,靶材表面的蒸发效应使得靶材表面 温度上升显著放缓;在激光辐照强度接近相爆炸能量阈值时,蒸发速度与蒸发厚度的变化由 于逆流现象将显著放缓.还得到了考虑了熔融弛豫时间及蒸发效应的固-液界面随时间的演化 方程,这一结论较先前工作更具有普适性.
关键词:
脉冲激光烧蚀
热流方程
温度演化
有限差分法 相似文献
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讨论了脉冲激光沉积法中烧蚀阶段熔融前靶材吸收率的变化对于其温度分布的影响. 给出了靶材吸收率随时间的变化规律,并在此基础上,利用较为符合实际的高斯分布表示脉冲激光输入能量密度,建立了相应的热传导方程. 结合适当的边界条件,利用有限差分法,以硅靶材和钨靶材为例,给出了靶材熔融前温度分布随时间和深度变化的演化分布规律,同时对相关过程的物理图像进行详细的讨论.对于吸收率的变化与脉冲激光能量密度的分布对于相应过程的影响,进行了分析讨论. 结果表明,在脉冲激光中间的持续过程中,忽略靶材吸收率的变化对于最终的模拟结果有重要影响,从而导致理论结果与实验数据有较大差异.
关键词:
脉冲激光沉积
吸收率
有限差分
温度演化 相似文献
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5 纳米技术51 纳米管用于微观探测[43]瑞斯(Rice)大学的斯玛勒(RSmalley)小组将单个碳纳米管粘合到隧道扫描显微镜和扫描力显微镜(scanningforcemicro-scopes)的探针上.纳米管长约几个微米,但宽只有5—20nm.这些长长、窈窕的探针可以再生,十分便宜;可以导电,用于探测粗糙的地方,甚至沟槽底部.不像标准的金字塔形探针,纳米管探针勘查表面时不易受损.当它和表面接触时只发生弯曲,当撤回时,立即弹性恢复原来准直形状.52 纳米技术中的计数[44]德国慕尼黑的… 相似文献
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3粒子、核和等离子体31夸克不具有明显的结构[19]1976年,基于质子-反质子对撞资料的分析,费米国家实验室对撞检测器(CDF)合作组发现,从大角度相互作用飞出的高能喷注事件比预计的多.有人(并非实验者自身)解释说,这或许是亚夸克存在的证据.为检... 相似文献
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We numerically investigate the effect of four kinds of partial attacks of multiple targets on the Barabási Albert (BA) scale-free network and the Erdos-Rényi (ER) random network. Comparing with the effect of single target complete knockout we find that partial attacks of multiple targets may produce an effect higher than the complete knockout of a single target on both BA scale-free network and ER random network. We also find that the BA scale-free network seems to be more susceptible to multi-target partial attacks than the ER random network. 相似文献
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An ablation model of targets irradiated by pulsed laser is established. By using the simple energy balance conditions, the
relationship between ablation surface location and time is derived. By an adiabatic approximation, the continuous-temperature
condition, energy conservation and all boundary conditions can be established. By applying the analytical method and integral-approximation
method, the solid and liquid phase temperature distributions are obtained and found to be a function of time and location.
The interface of solid and liquid phase is also derived. The results are compared with the other published data. In addition,
the dynamics process of pulsed laser deposition of KTN (Kta0.65Nb0.35O3) thin film is simulated in detail by using fluid dynamics theory. By combining the expression of the target ablation ratio
and the dynamic equation and by using the experimental data, the effects of laser action parameters on the thickness distribution
of thin film and on the thin film component characteristics are discussed. The results are in good agreement with the experimental
data. 相似文献