入射

The main works include: In this thesis, we use Finite Difference Time Domain method to study the relationship between diffraction efficiency, angular dispersion and grating constant, to discuss how the grating figure influence the diffraction efficiency, and to research the frequency spectrum characteristic.

主要工作包括：本文分别在垂直入射和自准直入射（光垂直于光栅刻槽面入射）情况下，采用时域有限差分方法，利用商业数值计算软件OptiFDTD对二维闪耀光栅进行了矢量电磁场数值计算，研究了光栅的衍射效率和角色散随光栅常数的变化情况，研究了光栅形状对光栅衍射效率的影响，还讨论了各种光栅的频谱特性。

Based on the relations of the diffraction field and the surface wave, which conclude diffraction factor and interference factor, some relations were conformed such as: the diffraction fringes spatial distribution versus surface wavelength, the fringes half angular width versus the numbers of surface wave covered by laser spots and incidence angle, diffraction intensity versus surface wave amplitude.

通过对衍射因子和干涉因子的分析，得到衍射条纹空间分布与表面波波长的关系、条纹的半角宽度与入射激光光斑覆盖表面波的个数和入射方向的关系、衍射光强度与表面波振幅的关系，并解释了条纹缺级现象。

In order to testify our whether correction to Rossi's exchange term andthe potential of electron and nucleus is reasonable, we calculate 〓 moleculeelastic differential scattering cross section by electron impact on 100eV, ourresult is obviously better than Rossi's. Then we calculate elastic differentialscattering cross section at 150eV. In order to check the program thatcalculates molecule excitation cross section by electron impact, we calculatehydrogen excitation cross section from ground state to 〓 state at 20eVand 30eV, oxygen excitation cross section from ground state to 〓 state at15eV and 20eV. These calculations are in agreement with other theoreticresults, and experiment measure. Finally, we calculate sulfur moleculeexcitation〓 cross section by electron impact at5eV,7eV,9eV, 11eV, 13eV,15eV, and draw curve of excitation total crosssection corresponding to incident electron energy.

为了核对我们修改的计算激发态的程序是否正确，计算了电子与氢分子碰撞从基态激发到〓态入射能量分别为20eV和30eV时的微分截面以及电子与氧分子碰撞从基态激发到〓态入射能量分别为15eV和20eV时的微分截面，与别人的理论计算结果、实验的测量值基本一致，最后计算了电子与硫分子在5eV、7eV、9eV、11eV、13eV、15eV时的碰撞激发〓截面，作出了电子的入射能量与激发总截面的关系曲线，找出了总截面最大时对应的电子入射能量大约是11电子伏。

According to the boundary relations of the electromagnetic field, and based on the phenomena of double refraction and double reflection in crystals, the reflectivity and transmissivity are deduced at boundary when an extraordinary beam is incident from an isotropic medium upon a crystal or from a crystal to an isotropic medium with optical ax.

为分析非常偏振光在晶体表面的能量损耗，给出一种求解反射率和透射率的方法，即根据电磁场的边值关系以及晶体的双折射和双反射现象，求解晶体光轴在入射面内时，非常偏振光从各向同性介质入射到晶体和从晶体出射到各向同性介质两种情况的反射率和透射率的方法，并给出反射率和透射率的解析解，同时得到对于晶体光轴在入射面内的情况，光轴的取向对非常偏振光反射率的大小几乎没有影响，但对产生全反射的临界角θc影响较大的结论。

Second order incident boundary condition on fixed incident boundary is derived for numerical simulations, based on the cnoidal or sinusoidal motions of wave maker paddle, which shows that the prediction with second order incident boundary condition is more accurate than the prediction with first order incident boundary condition. 2 The analytical solution for higher-order Boussinesq equations is derived and its applicable range is discussed. 3 A 2-D fully non-linear numerical model using boundary element method is developed to obtain wave forces acting on rectangular obstacle. 4 The three-dimensional fully non-linear waves are studied in a numerical wave tank using finite element method.The studies on the coupled numerical model combined Boussinesq equations with Laplace equation are following.

非耦合非线性波浪计算模型：1 根据造波板做椭圆余弦运动或正弦运动速度，推导出数值模拟波浪水槽时固定入射边界上的二阶波浪入射边界条件，数值计算结果和实验结果的对比表明采用二阶入射边界条件对波面升高的预报比采用一阶入射边界条件对波面升高的预报更为精确；2 推导了波浪水槽造波板做正弦运动所产生波浪的高阶Boussinesq方程摄动展开解析解，讨论了该解析解的适用范围；3 对整个波浪水槽应用边界元方法数值模拟了波浪对物体的非线性作用；4 用有限元法求解三维Laplace方程模拟了三维完全非线性波浪水槽。

The result indicates that the output power oscillates and weakens along with increasing input power,and its oscillation period depends on the distance between the medium and beam focal point.Limiter′s limiting ability will decrease if waist size of the incident Gaussian beam and the aperture size increase.With a fixed input power scope,medium′s best limiting position will move towards the focal point if waist size of Gaussian beam and the aperture size increase,but the best limiting position will change a lot with different input power scopes.

结果表明：限幅器的出射功率随入射功率的增加衰减振荡，其振荡周期取决于介质相对于光束焦点的位置；限幅器的限幅能力随入射光束腰半径和光阑孔径的变大而减弱；入射功率范围固定，入射光束腰半径和光阑孔径增大时，介质的最佳限幅位置向入射光束的焦点靠近，但是在某些入射功率范围内会存在多个最佳限幅位置；光限幅器的箝位输出功率随光阑线性透过率的增加存在线性增加和非线性增加两个不同区域，实际应用中应在线性增加区域确定光阑孔径的大小。

A FDTD program was written and the electromagnetic fields for various polarized incident beams are calculated and the polarization states of the diffractive waves are extracted. The relation between the polarization state of the diffraction wave and the grating balzed angle and polarization angle for the linearly polarized incident wave is analyzed; In the spectral range of 1530 ~ 1570nm, the polarization dispersion is studied for the linearly and circularly polarized incident beam.

用时域有限差分程序计算出任意偏振方向线偏光经过闪耀光栅衍射后的电磁场分布，提取衍射波的S偏振和P偏振分量，分析它们与光栅闪耀角和入射光波偏振角的关系；分析在1530 -1570nm光谱范围内，入射光波为线偏振波和园偏振波时，衍射光波的偏振色散特性与光栅闪耀角的关系。

Results show that amplitude of displacement excited by vertical incidence wave is larger than that excited by inclined incidence wave and not influenced greatly by the incidence angle. In vertical incidence, amplitudes of displacement of two points at the same altitude along each cavern are basically identical and maximum relative displacement occurs between top and bottom point of the cavern. While in the case of inclined incidence, displacement amplitude on sides meeting the wave is larger than that on leed sides, and maximum relative displacement occurs on left skewback and bottom of the cavern.

结果表明，位移幅值受入射角度的影响不敏感，竖直入射比斜入射情况要大；竖直入射时，各洞室两侧同一高程处的位移幅值基本相同，相对位移差最大部位为洞顶与洞底，而斜入射时迎波面比背波面一侧位移大，且相对位移差最大部位为洞室迎波面的左拱座与洞底。

Based on the research on the scattering of the Gaussian beam from single sphere, the intensity distributions of LGB beam in different propagation distance is analyzed. Without considering the relationship of scattering and phase shift, the beam coefficients is gained by the solution of scattering cross section, and the LGB is expanded in terms of the vector spherical harmonics as fundamental Gaussian beam. The scattering of the beam with orbital angular momentum from single sphere located on the propagation axis is studied.

在单体球粒子对高斯光束散射研究的基础上，分析了在自由空间不同传输距离LGB光束的光强分布情况，在不考虑散射和波束相移关系的情况下，将LGB作为入射高斯光束，通过对波束入射时的散射衰减截面求解得到波束因子，利用矢量球谐函数对入射高斯波束进行展开，从而研究了单球粒子在在轴条件下对具轨道角动量高斯波束入射的散射问题。

We then add boundaries delineated forward/backward facing reflected shock, Mechanical equilibrium, M2=1 and reflected shock strong/weak separating conditions on the (M0,q1) map of shih(2004). This is followed by systematically investigating multiply possible three shock theoretical solutions of steady Mach reflections in perfect triatomic gases. Pressure-deflection shock polar solutions are used to help illustrate different solution behaviors of these theoretical three-shock solutions. M0 is flow Mach no. upstream of incident shock, M1 is flow Mach no. downstream of incident shock, M2 is flow Mach no. downstream of reflected shock,q1 is flow deflection downstream of incident shock.

随后本文由石(2004)论文中加入前后分界、机械平衡、M2=1及强弱分界条件，然后有系统地探讨三原子分子理想气体(r=1.2857 )稳态马赫反射参震波理论多重解之交点及其对应之压力-转折角震波极图解，并建构出此三原子分子理想气体稳态马赫反射流场三震波十阶多项式理论解於(Mo，q1)平面上之解域图，其中M0为入射震波上游流场马赫数，M1为入射震波下游流场马赫数，M2为入射震波下游流场马赫数，q1为入射震波下游流场转折角。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了