Study of nanocrystalline Fe－Al－N soft magnetic thin films

Fe－Al－N films were fabricated by reactive sputtering using a radio-frequency magnetron sputtering system. The effects of Al and N content and annealing temperature on microstructure and magnetic properties were investigated. The Fe－Al－N films, which have good soft magnetic properties, consist of nanocrystalline α-Fe grains and a small amount of other phases in the boundaries of α-Fe grains. The average α-Fe grain size is about 10－15nm. A slight amount of Fe－N and Al－N compounds precipitate in the boundaries of α-Fe grains and suppress their growth. Annealing improves the soft magnetic properties slightly by releasing the residual stress and reducing defects.     

Nuclear Level Density and Thermodynamic Functions for Nuclei with Static Deformation

The level densities of even-odd and even-even isotopes^161,162Dy,^166Er and ^171,172Yb were calculated using microscopic theory of interacting fermions and compared with experiments.It is found that the data can be well reproduced with level density formalism for nuclei with static deformation.The nuclear temperature as well as the reproduced with level density formalism for nuclei with static deformation.The nuclear temperature as well as the entropy of nuclear system as a function of excitation energy has been extracted from the BCS theory.It is shown that the entropy exhibits an S-formed shape as a function of excitation energy.This is interpreted as a phase transition.Procedure of treating the even-odd and even-even nuclear systems has been presented and discussed.     

A New Higher Order Shear Deformation Model for Static Behavior of Functionally Graded Plates

In this paper, a new displacement based high-order shear deformation theory is introduced for the static response of functionally graded plate. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory presented is variationally consistent, has strong similarity with classical plate theory in many aspects, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Numerical illustrations concerned flexural behavior of FG plates with Metal-Ceramic composition. Parametric studies are performed for varying ceramic volume fraction, volume fraction profiles, aspect ratios and length to thickness ratios. The validity of the present theory is investigated by comparing some of the present results with those of the classical, the first-order and the other higher-order theories. It can be concluded that the proposed theory is accurate and simple in solving the static behavior of functionally graded plates.     

双面电弧焊接的传热模型

将等离子焊接(PAW)电弧和钨极氩弧焊(TIG)电弧串接,相对作用于工件的正反面形成双面电弧焊接(DSAW)系统,可以引导焊接电流沿工件厚度方向流过小孔,补偿等离子电弧穿透工件时消耗的能量,以有效地提高等离子弧的穿透能力.综合考虑影响双面电弧焊接正反面熔池几何形状的力学因素,建立了熔池表面变形的控制方程,以此为基础并采用帖体曲线坐标系建立了DSAW焊接传热的数学模型,分析了DSAW,PAW焊接传热的差异,从传热的角度解释了DSAW焊接熔深增加的原因.焊接工艺实验表明,计算结果与实测结果吻合良好. 关键词： 双面电弧焊接(DSAW) 传热模型 熔池表面变形模型     

主动抛光盘面形测试技术的研究

主动抛光盘技术是新发展起来的一种能够根据需要将抛光盘面实时地主动变形成离轴非球面来磨制深非球度高精度天文镜面的磨制技术。简单介绍了抛光盘变形控制结构和面形检测机构，对深非球面度面形变形进行了精度分析，探讨了主动抛光盘的动态响应和校正，并对抛光盘的改造提出了一些建议。     

振动波包法模拟氢溴酸光解离动力学

研究了在零度和非零度时的双原子分子离子HBr⁺在不同包络函数的超快激光脉冲作用下的光解离动力学. 主要计算了HBr⁺电子基态时的参数. 利用从头算理论在CCSD/6-311++G(3df,2pd)水平计算了HBr+的势能值,用Morse参数模拟后,与非依时傅立叶格点哈密顿方法获得的束缚态振动能量本征值进行比较. 另外,探索了温度、脉冲包络函数和光强度对光解离过程的影响.     

22nm极紫外光刻物镜热和结构变形及其对成像性能影响

极紫外光刻技术(EUVL)是半导体制造实现22nm及其以下节点的下一代光刻技术。在曝光过程中,EUVL物镜的每一面反射镜吸收35%～40%的入射极紫外(EUV)能量,使反射镜发生热和结构变形,影响投影物镜系统的成像性能。基于数值孔径为0.3,满足22nm技术节点的产业化EUV投影物镜,采用有限元分析(FEA)的方法研究反射镜变形分布,再将变形导入光学设计软件CODE V中,研究反射镜变形其对成像特性的影响。研究结果表明:当达到硅片的EUV能量为321mW,产量为每小时100片时,反射镜最高升温9.77℃,通光孔径内的最大变形为5.89nm;若采用相干因子0.5的部分相干光照明,变形对22nm线宽产生6.956nm的畸变和3.414%的线宽误差。     

二维非极性晶体中声学形变势表面磁极化子

本文研究磁场中二维非极性晶体通过形变势与声学声子强、弱耦合的表面极化子的性质。采用线性组合算符和拉格朗日乘子法导出表面磁极化子的基态能量。讨论了表面磁极化子的振动频率、基态能量和有效质量与磁场的关系。     

双参数变形玻色湮没算符高次幂的本征态及其量子统计性质

本文构造了双参数变形玻色湮没算符高次幂a^'k(k≥3)的k个正交归一木征态的数学结构,发现它们能构成一个完备的Hilbert空间,并且讨论了它们的量子统计性质.     

In situ three‐dimensional reciprocal‐space mapping during mechanical deformation

Mechanical deformation of a SiGe island epitaxically grown on Si(001) was studied by a specially adapted atomic force microscope and nanofocused X‐ray diffraction. The deformation was monitored during in situ mechanical loading by recording three‐dimensional reciprocal‐space maps around a selected Bragg peak. Scanning the energy of the incident beam instead of rocking the sample allowed the safe and reliable measurement of the reciprocal‐space maps without removal of the mechanical load. The crystal truncation rods originating from the island side facets rotate to steeper angles with increasing mechanical load. Simulations of the displacement field and the intensity distribution, based on the finite‐element method, reveal that the change in orientation of the side facets of about 25° corresponds to an applied pressure of 2–3 GPa on the island top plane.