利用面波频散反演场地参数的Occam法   总被引：2，自引：2，他引：2  

欧阳联华  王家林  吴健生 《物探化探计算技术》2003,25(1):1-4

将Constable等人1987在解释大地电磁测深资料时提出的Occam反演方法应用到面波频散反演之中，其思路是求满足一定的残差条件下的最光滑的模型。从文中反演的几组数据结果来看，该方法在面波反演中的应用效果是令人满意的。  相似文献   

江苏高邮地震台地磁变化与地震关系的初探   总被引：1，自引：1，他引：1  

赵卫红  蒋延林  赵永红  王福才  赵峰  张骞  李凤如 《山西地震》2003,(4):36-39

分析了江苏高邮地磁台1980年至2002年地磁垂直分量日变幅逐日比值的高值异常与江苏及邻区ML5．0以上地震之间的关系，发现它们之间有良好的对应关系，通过分析地磁垂直分量谐波幅度的逐日比，提出了适用于高邮地磁台的地震分析预报参数，并对其内检预报效能进行了评价。  相似文献   

Re-occurrence of site-specific response in former Yugoslavia—part II: Friuli, Banja Luka and Kopaonik     

M. D. Trifunac  S. S. Ivanovi 《Soil Dynamics and Earthquake Engineering》2003,23(8):663-681

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Modeling of Rayleigh waves dispersion in the Sannio region (Southern Italy) from seismic active refraction data     

Salvatore de Lorenzo  Giovanni Iannaccone  Aldo Zollo 《Journal of Seismology》2003,7(1):49-64

Short period surface waves, recorded during a seismic refractionsurvey in the Sannio region (Southern Italy), have been modeled to infera shallow velocity model for the area. Based on the decrease of resolutionwith depth, due to the bias on group velocity estimates arising frominterference of the Rayleigh waves with higher modes, we carried out aprocedure of fitting, with synthetic seismograms, of selected filtered traceswith a gaussian filter, having a width at half height equal to 1 Hz and acentral frequency lying in the range [1,4] Hz. We estimated the likelihoodbetween synthetic and observed seismograms by measuring their semblance.In this way we were able to infer a more refined local velocity modelcharacterized by a high Vp and Vs vertical gradient in the sedimentarycover. Two ad hoc resolution studies, based on group velocity andamplitude data respectively, indicate that the local velocity model is a goodvelocity model also for the entire studied area. The increase in the numberof available data when using amplitude information allows us to make amore selective choice in the model parameter space (Vp and Vs of eachlayer) and to solve for the Vp/Vs ratio. The inferred Vp velocity in thehalf-space is equal to 2.8 km/s. This value is in excellent agreement withthat inferred by other authors (3 km/s) by modeling P-wave travel timevs. distance. The best-fit model furnish low Vp/Vs for the sedimentarycover so indicating a high degree of the sediment's compaction in thestudied area. The inferred shallow high-velocity gradient indicates thatthe shallow sedimentary layer in the area could trap and focus the energytraveling into it.  相似文献   

Comparison of the Langrangian Footprint     

N. Kljun  R. Kormann  M. W. Rotach  F. X. Meixer 《Boundary-Layer Meteorology》2003,106(2):349-355

We compare flux and concentration footprint estimates of athree-dimensional Lagrangian stochastic dispersion modelapplying backward trajectories with the results of ananalytical footprint model by Kormann and Meixner.The comparison is performed for varying stability regimesof the surface layer as well as for different measurementheights. In general, excellent correspondence is found.  相似文献   

登陆热带气旋的大暴雨天气与一般暴雨对比分析及其雨强增幅原因的初探     

沈树勤  胡洛林 《气象科学》1997,17(3):290-297

本文以９０１５号热带气旋登陆后造成的省淮以南大暴雨天气为例，与８闪一般暴雨天气的热力动力条件进行对比，分析它们之间的异同点，并利用二维点尺度力学模式对地面中尺度锋区引起民环流进行模拟试验，结果表明，在热带气旋伸向东北部一条辐合线的偏北旗帜的中尺度锋区驱动扰动涡旋，在涡旋的上升部位可对大暴雨有增幅作用。  相似文献   

UNIVERSALITY OF THE LAGRANGIAN VELOCITY STRUCTURE FUNCTION CONSTANT (C0) ACROSS DIFFERENT KINDS OF TURBULENCE     

SHUMING DU 《Boundary-Layer Meteorology》1997,83(2):207-219

In this paper, we evaluate the Lagrangian velocity structure function constant, C0, in the inertial subrange by comparing experimental diffusion data and simulation results obtained with applicable Lagrangian stochastic models. We find in several different flows (grid turbulence, laboratory boundary-layer flow and the atmospheric surface layer under neutral stratification) the value for C0 is 3.0 ± 0.5. We also identify the reasons responsible for earlier studies having not reached the present result.  相似文献   

多标度分形与地球化学场分解   总被引：3，自引：0，他引：3  

孟宪伟  张晓华 《地质与勘探》1996,(4)

在地球化学叠加场内，不同时期、不同规模的地质作用形成的地球化学景观具有不同的分形标度区间和分维。利用多标度分形方法把黑龙江省团结沟金矿外围的叠加地球化学场分解成了分别与北东向和北面向构造相对应的地球化学正常场和异常场，并在此基础上，讨论了地球化学场的演化。  相似文献   

High Pressure-Differential Thermal Analysis and Ultrasonic Wave Amplitude Analysis of Ice-Water Equilibrium at 1.5-5.0GPa     

Xu Yousheng  Zheng Haifei  Xie Hongsen  Zhang Yueming  Xu Huigang  Guo Jie 《中国地球化学学报》1996,15(2):153-158

Water is the most active component in all geological systems.It has an important effect on the physical properties of minerals and melts.It also plays a key role in the evolution of the Earth.Accurate thermodynamics data on water are currently confined to pressures below 1.0GPa and temperatures below 900℃.Presented in this paper are new data available on the P-T properties of water at pressures up to 5.0GPa,develoged from differential thermal analysis and ultrasonic wave amplitude analysis.It has been found that there may exist another ternary point at 3.0GPa and that ultrasonic wave amplitude change of ice-water transition shows two inflection points above 2.0GPa, consistent with the two peaks of differential thermal curves above 2.0GPa .It may be a new phenomenon which needs further study.  相似文献   

裂隙岩体中的对流扩散研究     

陈尤雯  莫海鸿 《岩土力学》1997,18(3):47-52

揭示一个基于代数拓扑理论的裂隙网络中物质弥散模型，还给出了应用于网络中的对流扩散的对应性原理的证明。应用拓扑理论给出的框架，使其起了一个数据结构的组织者的作用，由此得到网络中每一个分支上的浓度的解。这个解是在拉普拉斯空间上的解析解。网络中任意点在任何时刻的浓度可以很方便地用数值拉氏反变换求出。  相似文献