According to the mean size measurement based on diffraction , we put forward a new method by calculating the ratio of two scattering light intensity at different scattering angle , which can solve the problem caused by the diffraction method 文中根据衍射法求取平均粒度的方法，提出了用两个不同散射角的散射光强比求取平均粒度的方法，解决了衍射法测平均粒度的缺点。
Then we also presented the simple way to solve the polydisperse powder concentration by calculate it as monodisperse powder , compared the measurement results which were got at different diameter , scattering angle and distribution 然后本文还分析了将具有尺寸分布尘粒的浓度测量按单一粒径尘粒进行近似测量的计算情况，并比较了它们在不同粒度、不同测量角度、不同分布参数情况下的差异。
The energy loss of protons or silicon nuclei due to nuclear scattering is calculated using binary collision approximation and the " magic " formula is used to calculate the scattering angle . the electronic energy loss is calculated by bethe - bloch formulation at high energy , by linhard - scharff formulation at low energy and the interpolation formulation is used for the medium energy region . the nuclear reaction is calculated using intra - nuclear cascade model 核散射采用经典两体碰撞近似，并用“梦幻”公式求解散射角；电子阻止在高能时采用bethe - bloch公式，低能时采用lindhard - scharff公式，中能时采用biersack的插值公式；核反应过程采用核内级联模型。
In the first part , the basic knowledge of particle scattering in meteorology and physics was introduced . the particles to be discussed include aerosol particles , fog droplets and raindrops and the em wave band in the discussion is near - infrared . in the second part , the mie theory was briefly reviewed and was applied to investigate the scattering characteristics of spherical atmospheric particles , the result shows that in the visibility measurement meter using forward - scattering method , when the working wavelegth is between 0 . 8 m ~ 2 m , the scattering angle is between 25 ~ 40 , the distinguishability and the relative scattering intensity would be better than those under other conditions . in the third part , the superellipsoid was used to describe a wide range of shapes such as spheres . ellipsoids and cylinders . an improved t - matrix method which can be used to calculate arbitry shaped particle ' s scattering field was introduced , and the scattering characteristics of non - spherical atmospheric particles was investigated with this method 计算结果表明，从相对散射强度、同一方向上不同粒子散射的可区分程度来看，在散射式能见度探测仪器中，工作波长介于0 . 86 m 2 m ，探测角度选取前向25度40度时，探测的结果将会是比较理想的。第三部分中，使用超椭球方程来统一描述各种非球形粒子的形状，然后使用t矩阵方法计算了一些形状的非球形粒子的近红外散射特性。另外，在本文中还针对球形粒子的散射场提供了一种三维可视化方法，使对散射场强度的空间分布的理解更加简单，直观。
The conclusions are as follows : the ultrasonic intensity is proportion to the laser intensity ; the ultrasonic induced by a laser line source has much more advantages than by a laser point source , such as stronger energy , higher snr , more directivity and shape ; the intensity of cfpi ' s output signal is linear with ultrasonic vibration velocity , and is effected by incidence angle and scattered angle ; snr will increase by reducing cfpi ' s bandwidth , reducing incidence angle , increasing cavity ' s length and reflectivity 在分析点光源激励声表面波机理的基础上，求出了线光源激励的超声振动的位移表达式，发现线光源激励的近场区表面波具有波形好，信噪比高，指向性好，幅度强等特点。通过理论推导，得出共焦fabry - perot干涉仪的输出光强除了与样品表面的振动速度成正比，并与入射角和散射角有关；适当减小cfpi的带宽，增加腔长，增大镜面反射率，或者减小检测入射角都可以提高系统的信噪比。
Based on the theory of glow discharge , the angle distribution of electron and the recombination process are simulated by adopting monte carlo method . the doping process of n - type diamond film is investigated by this method for the first time . the results indicate : 1 ) the scattering angle of electrons near the substrate is mainly lange - angle , which is helpful to grow diamond film over a large area when glow discharge is kept ; 2 ) after considering the recombination process , the number of particles distribution is provided 主要结果如下： ( 1 )研究了电子在雪崩碰撞和分解电离后的角分布情况，结果表明基片附近电子的散射以大角散射为主，在维持辉光放电的条件下，较高的偏压和工作气压对金刚石的横向连续成膜是有益的； ( 2 )考虑了低温合成金刚石薄膜过程中电子与各种碎片粒子的复合过程，给出了不同的复合系数情况下的粒子数分布，结果显示各种碎片粒子的分布随复合系数的变化会出现粒子数分布的涨落现象。
