The effects of sediment parameters on the multi - path structure in shallow water are investigated in detail . a method of dividing the multi - path arrival time differences into groups is presented . theoretical analysis for the method is given 详细研究了沉积层声速、密度和衰减系数变化对浅海多途到达结构的影响，提出了对多途到达时延差进行分组的研究方法，从理论上对该方法进行了研究。
Firstly , an estimation algorithm for spectrum of the ct system is presented in the paper by using a standard cylinder or wedge phantom , where the mass attenuation coefficient of the contained material of the phantom is not necessarily to be known 本文首先给出了由标准均匀圆柱状模体或楔状模体估计ct系统的x射线能谱的算法，该算法不必已知构成模体的物质关于不同能量的光子的质量衰减系数。
Generally speaking , the high group velocity and low attenuation factor and high qr in the same area , but relatively low group velocity and high attenuation factor and low qr in the same area in china is the general distribution 在不同周期，面波衰减系数或品质因子在整个中国大陆区域分布是不均匀的；总体表现为高群速度分布的区域呈现高丛和低衰减系数、低群速度分布的区域呈现低丛和高衰减系数分布的特点。
The damping coefficient of the laminated composites is more than twice that of ly12 aluminum alloy . furthermore , the damping coefficient of laminated composite is enhanced with the increasing of thickness of fiber / resin layer . the vibration damping mechanism is analyzed 研究了不同纤维树脂层厚度时叠层复合材料的阻尼性能，发现随中间层厚度的增加，叠层复合材料的振动衰减系数增加，并分析其振动衰减机制。
Then , according to waveguide theory , planar waveguide is analyzed . the main parameters , such as spread constant , decay coefficient , cut - off wavelength and so on , are deduced from dispersion formula of planar waveguide . the distributions of electromagnetic wave in the planar waveguide are obtained also 其次根据波导理论分析了平面波导，由平面波导的色散方程推导出了导模的传播常数、衰减系数、截止波长等特征参数以及波导中光波电磁场的分布。
The initial model ( vs , vp , qb , p ) based on previous work of this research group is adopted , and by terms of the relationship between the attenuation factor and s - wave quality factor , the stochastic least square is conducted to inverse the o > > of ail layers under every grid , i . e . the qb structure of every uiut - column Q _ 、 p ) ，利用衰减系数和层内s波品质因子q _之间的关系，通过阻尼最小二乘法反演方法反演每个单元格内各层q _ ，得到每个“单元柱”的q _三维结构
This is of very important significance to understand the material property and geodynamic of corresponding area , , the surface wave attenuation mechanism and the inversion algorithm of attenuation and s - wave quality factor are discussed systemically in this paper . some important fruits and understanding are resulted from the the crust and upper mantle tomography of china . ( 1 ) calculating of the rayleigh surface wave attenuation factor y 本文首先探讨了面波衰减的机理，对面波衰减和s波品质因子q _反演的计算方法进行了系统的研究，并对中国大陆地区地壳上地幔q _三维结构进行层析成像，取得了以下重要成果： ( 1 ) rayleigh面波衰减系数计算。
It is found that if the cavity dissipation is losses and the reservoir is in vacuum , the quantum nonlocality appears periodically . when the cavity dissipation and the average photon number of the reservoir are taken into account , the initial quantum nonlocality will be lost . the rapidity of the loss of the initial quantum nonlocality depends on the amplitude of the initial field , the average photon number n and the cavity damping constant k 结果表明，如果腔场无损耗且处于真空库，则量子态周期性地显现出一定的非局域性；如果考虑到腔场的损耗和热库的平均光子数，那么，量子态将会丧失它初始的非局域性，初始量子非局域性丧失的速度与初始腔场的幅度、腔的衰减系数以及热库的平均光子数有关，场越强、平均光子数和衰减系数越大，量子非局域性丧失得就越快。
A dynamical system is built which is satisfied to lyapunov function whose energy function is penalty function in augmented lagrange multiplier method . the dynamical system is global stable , and its stable solution is the optimization solution of sub - problem in augmented lagrange multiplier method according to lasalle invariance principle . finally a complete optimization algorithm is developed 针对这种工业过程，本文基于一个lqr的性能指标（本性能指标和衰减系数和自然频率密切相关） ，提出应用本文提出的mmlaax优化算法，对不确定工业过程进行鲁棒pto控制器的设计，取得令人满意的效果。
X4 ? gridding attenuation and 2 ? x2 ? gridding group velocity are calculated respectively , based on the attenuation and velocity , the distribuation of rayleigh wave quality factor qr are yielded finally . ( 3 ) building the s - wave quality factor og3d structure of the continental crust and upper mantle of china area 为此把中国大陆区域划分成4 4网格和2 2网格，利用lsqr方法分别进行衰减系数和群速度网格化反演，得到4 4单元格的衰减系数分布和2 2单元网格的群速度分布。
