Numerical Simulation of the Response Features of Apparent Seismic Wave Velocity Ratio in a Horizontal Layered Medium

This paper deals with the response features of AR(apparent ratio of seismic wave velocities to the changes of TR(true ratio of wave velocities)in the horizontal layered model by mathematical modeling.The results show that:(1)the response features of AR are associated with the parameters of the structure and its dynamic changes,and the relative position between the hypocenters and the monitoring networks,showing complicated patterns strongly related to the concrete paths of propagation of seismic waves from the source to the receiver in the observatories of the network;(2)the depth of the seismic source would have important influence on the response features of AR,especially the capacity to carry the anomalous information in the condition of the earth media,being in the anomalous state would be greater for those earthquakes which occur inside the anomalous layers than those underneath the anomalous layers;(3)the response features of AR are clearly related to the changes of TR(true ratio of wave velocities)instead of changes of wave velocities themselves,i.e.the response could be small as the changes in TR is small even in the case of large changes in the wave velocities.It is suggested that more attention must be paid to all these features in combination with detailed investigation of the velocity structure of the earth media in the study region and best fitting of precise hypocenter locations when one wants to obtain the reliable precursors from the changes in AR.

Analysis of the co-seismic responses of the fluid well pattern system in Jiangsu Province to the Wenchuan and Tohoku earthquakes

This thesis discusses the earthquake reflecting ability of the observation well pattern system of Jiangsu Province, China, which has been digitally renovated, and probes into the cause of the major differences in the earthquake reflecting abilities of well holes at different measurement points. This is achieved through the analysis of the co-seismic responses to the Wenchuan (2008; Ms8.0, China) and Tohoku (2011; Ms9.0, Japan) earthquakes. We found that the co-seismic response of water level from regional well holes in Jiangsu Province was stronger than that of water temperature. The water-level co-seismic response follows a consistent law and is closely related to the earthquake magnitude. The co-seismic response of water temperature strongly varied among well points, and was more often manifested as a slow restorative change. The co-seismic responses also varied based on tectonic elements. The response in central and northern Jiangsu was weaker than that of southern Jiangsu, possibly due to the thicker loess cover layer in central Jiangsu which makes it less effective at capturing the micro-changes of stress-strain states relative to the hilly land in the south. The more complicated geological structure in southern Jiangsu makes it contribute to greater changes in the state of underground water after a minor disturbance.

Clinical features of autoimmune hepatitis patients with poor response to treatment

Objective To investigate the clinical features of autoimmune hepatitis(AIH)patients with poor response to treatment.Methods A total of 61 AIH patients were enrolled,among whom 49(80.33%)achieved complete response(good response group)and 12(19.67%)had incomplete response(poor response group).The

A method for active deception jamming discrimination based on frequency response

There are many types of radar active deception false target jamming that are highly correlated with the real target.Recognizing the real and false targets under a low Signal-to-Noise Ratio(SNR)is difficult.To solve the above problem,this article proposes a real/false target recognition method based on the features of multi-pulse joint frequency response by analyzing the differences in the scattering characteristics and modeling real target echoes as a synthesis of multi-scattering center echoes.Firstly,in the range-doppler domain,the real and false targets are truncated along the range dimension,and a fast Fourier transform is performed to extract the features of multi-pulse joint frequency response.Then,a two-channel feature fusion network is designed for real and false target recognition.Finally,a Multi-Coherent Processing Interval Joint Decision Method(M-CPIJDM)based on temporal information is proposed to improve the recognition performance.Experiments using the measured data show that the proposed method can well recognize real and false target signals under four jamming backgrounds:distance false target,velocity false target,distance-velocity composite false target,and forwarding dense false target.