透明激光陶瓷散射损耗分析

 为了定量分析激光陶瓷中散射损耗对其透过率的影响,通过建立气孔尺寸分布模型,引入第二相体积比概念,并结合Mie散射、瑞利散射和全散射积分等理论,讨论了激光陶瓷中气孔、晶界第二相和表面粗糙度等引起的散射损耗对激光陶瓷透光性能的影响。研究结果表明：气孔率的大小将明显影响陶瓷透过率,且气孔尺寸分布决定了透过率包络的变化趋势;晶界和表面散射对透过率的影响主要集中在短波长处;在气孔率较低情况下,晶界第二相的存在是导致短波长处透过率急剧降低的主要因素。     

Improved charge trapping flash device with Al2O3/HfSiO stack as blocking layer

In this paper, we investigate an Al₂O₃/HfSiO stack as the blocking layer of a metal-oxide-nitride-oxide-silicon-type (MONOS) memory capacitor. Compared with a memory capacitor with a single HfSiO layer as the blocking layer or an Al₂O₃/HfO₂ stack as the blocking layer, the sample with the Al₂O₃/HfSiO stack as the blocking layer shows high program/erase (P/E) speed and good data retention characteristics. These improved performances can be explained by energy band engineering. The experimental results demonstrate that the memory device with an Al₂O₃/HfSiO stack as the blocking layer has great potential for further high-performance nonvolatile memory applications.     

Novel high-voltage self-adaptive power device based on interface charge＊

This paper presents a novel high-voltage lateral double diffused metal-oxide semiconductor （LDMOS） with self- adaptive interface charge （SAC） layer and its physical model of the vertical interface electric field. The SAC can be self-adaptive to collect high concentration dynamic inversion holes, which effectively enhance the electric field of dielectric buried layer （EI） and increase breakdown voltage （BV）. The BV and EI of SAC LDMOS increase to 612 V and 600 V/tim from 204 V and 90.7 V/ttm of the conventional silicon-on-insulator, respectively. Moreover, enhancement factors of r/which present the enhanced ability of interface charge on EI are defined and analysed.     

Modelling of multi-bodies in close proximity under water waves——Fluid resonance in narrow gaps

Viscous fluid model and potential flow model with and without artificial damping force(f=-μV,μ the damping coefficient and V the local averaging flow velocity) are employed in this work to investigate the phenomenon of fluid resonance in narrow gaps between multi-bodies in close proximity under water waves.The numerical results are compared with experimental data available in the literature.The comparison demonstrates that both the viscous fluid model and the potential flow model are able to predict the res...     

Solution to the MHD flow over a non-linear stretching sheet by homotopy perturbation method

In this study,by means of homotopy perturbation method(HPM) an approximate solution of the magnetohydrodynamic(MHD) boundary layer flow is obtained.The main feature of the HPM is that it deforms a difficult problem into a set of problems which are easier to solve.HPM produces analytical expressions for the solution to nonlinear differential equations.The obtained analytic solution is in the form of an infinite power series.In this work,the analytical solution obtained by using only two terms from HPM soluti...     

量子系统保结构计算新进展

本文主要介绍量子系统保结构计算最新进展情况,分以下几部分内容:哈密顿系统的辛算法、适合于量子系统的哈密顿量显含时间的辛算法、A2B模型分子和双原子分子系统的经典轨迹辛算法计算、双原子分子CO在激光场中的经典轨迹的辛算法计算及其振动和解离、定态Schr dinger方程的辛形式及求解定态Schr dinger方程本征值问题的辛 打靶法、含时Schr dinger方程的保结构算法及其在激光原子物理中的应用、伪分立态模型、强激光与原子相互作用的渐近边界条件、"非齐线性正则方程"的辛算法及其在计算强激光场中一维原子的多光子电离和高次谐波发射中的应用以及Heisenberg方程的保结构计算等等。     

非对称电极表面微观形貌对交流电渗流速的影响

经典交流电渗理论是利用电场进行非机械式微流体驱动的基础.传统理论交流电渗理论以双电层理论为基础,通过耦合电场方程以及流场方程得到微电极表面交流电渗流速表达式,通常与实验流速相差较大. 以电极表面微观形貌对交流电渗流速的影响为研究目标,定义微电极表面粗糙度为微观形貌特征参数,建立了等效双电层模型,并对传统交流电渗流速公式进行了修正.理论并仿真分析了表面粗糙度对于交流电渗流速的影响,利用非对称电极对交流电渗微流体驱动进行了实验研究,并进行对比分析.结果表明,理论分析与实验结果具有较好的一致性. 关键词： 交流电渗 电极表面粗糙度 等效双电层     

转捩边界层中流向条纹的新特性

基于边界层转捩后阶段的高精度直接数值模拟结果,发现流向条纹结构的低速条纹的演化过程中存在不连续现象,以及随高速条纹的发展会出现称之为"高速斑"的新特性. 通过详细剖析边界层转捩过程中的复杂涡系结构以及上喷下扫流动现象,证实流向高低速条纹新特性与流场涡系结构的演化过程紧密相关. 关键词： 流向条纹 边界层 转捩 直接数值模拟     

任意偏振激光作用下二维模型H原子的谐波发射

采用二维渐近边界条件和辛算法数值求解了任意偏振激光和H原子相互作用的二维含时Schrödinger方程的无穷空间初值问题. 计算了二维H原子在不同偏振激光作用下的谐波发射,得到各种椭圆率下谐波谱的特点与已有文献结果一致.通过电子的基态布居概率和某一时刻的概率密度分布以及电子的平均位移,对不同椭圆率下谐波谱的特点进行了分析. 结果表明,将渐近边界条件和辛算法推广到二维是合理和有效的. 关键词： 二维渐近边界条件 辛算法 任意偏振激光 高次谐波     

第一性原理方法研究He掺杂Al晶界力学性质

基于密度泛函理论方法,本文开展了氦掺杂AlΣ3((111)/180°)晶界数值模拟拉伸试验.计算结果表明,He在晶界中最低杂质形成能为2.942 eV,偏析到晶界的偏析能为0.085 eV;在拉伸条件下,清洁Σ3晶界的理论拉伸强度为9.65 GPa,拉伸断裂从晶界界面开始;而He掺杂后,晶界的理论拉伸强度下降到7.14 GPa,在断裂发生前应力曲线中出现平台效应,拉伸断裂从包含He杂质的界面开始.通过对比键长和电荷密度分布,本文认为He的满壳层电子结构一方面导致了He与Al之间 关键词： He 晶界 第一性原理计算 力学性质