搜索结果: 1-15 共查到“理学 VLF”相关记录34条 . 查询时间(0.144 秒)
Evolution of magnetotelluric,total magnetic field,and VLF field parameters in Central Italy:relations to local seismic activity
Magnetotelluroc tectonomagnetism VLF waves
2015/9/28
Magnetotelluric data were collected at Collemeluccio (41.72°N, 14.37°E) in Central Italy from summer 1991 to spring 1998. Analyzed by means of tensor decomposition on the geoelectric potential and rob...
Tectonomagnetic and VLF electromagnetic signals in Central Italy
tectonomagnetism seismomagneticnetwork seismic activity VLF
2015/9/14
Tectonomagnetic field observations from absolute magnetic field level measurements were undertaken in Central Italy in an area extending between latitude 41°N and 43°N and between longitude 13°E and 1...
Ionospheric perturbations associated with two huge earthquakes in Japan, using principal component analysis for multiple subionospheric VLF/LF propagation paths
Ionospheric perturbations Earthquakes Subionospheric VLF/LF propagation
2015/8/24
The presence of ionospheric perturbations in possible association with two huge earthquakes (Noto-hanto peninsula and Niigata-chuetu-oki earthquakes) in 2007 was studied on the basis of a conventional...
VLF-EM and VES: an application to groundwater exploration in a Precambrian basement terrain SW Nigeria
Electromagnetic (VLF-EM) Hard rock environment Groundwater development Layer resistivity Bed thickness mappingss mapping
2015/8/17
In a hard rock environment with surface or near surface expression of outcrops, the use of VES only becomes difficult due to its associated problems and limitations. However, the use of VLF-EM becomes...
VLF波渗透电离层传播计算研究进展
甚低频电磁波 计算方法 模型应用
2018/5/4
3~30kHz的甚低频（Very-Low-Frequency，VLF）电磁波对近地空间的高能粒子分布具有非常重要的作用.闪电和地面VLF通信台等VLF波主要辐射源产生的VLF波能够渗透进入电离层，并以哨声波模式继续传播至磁层与高能粒子发生相互作用.本文从VLF电磁波渗透电离层传播计算方法的发展、计算模型验证以及模型在电离层现象研究中的应用等方面对VLF波渗透进电离层之后的传播计算的研究进展进行综述...
VLF波渗透电离层传播计算研究进展
甚低频电磁波 计算方法 模型应用
2018/5/4
3~30kHz的甚低频（Very-Low-Frequency，VLF）电磁波对近地空间的高能粒子分布具有非常重要的作用.闪电和地面VLF通信台等VLF波主要辐射源产生的VLF波能够渗透进入电离层，并以哨声波模式继续传播至磁层与高能粒子发生相互作用.本文从VLF电磁波渗透电离层传播计算方法的发展、计算模型验证以及模型在电离层现象研究中的应用等方面对VLF波渗透进电离层之后的传播计算的研究进展进行综述...
电离层人工调制激发的VLF波在磁层的传播特性及应用研究
电离层人工调制 VLF波l射线追踪 波粒共振
2014/1/9
电离层人工调制可以激发甚低频（VLF）波，其中向上传播进入磁层的VLF波，不但能够用来研究磁层中的各种物理现象，且具有人工沉降高能粒子，消除辐射带等实际用途.本文使用射线追踪方法，模拟电离层调制激发的VLF波在磁层的传播路径，分析激发纬度和调制频率对传播路径和传播特性的影响；并基于低频波的色散方程和波粒共振条件，分析VLF波传播路径上与磁层高能粒子的最低共振能及其分布.研究表明，VLF波通过在磁层...
Anomalies Observed in VLF and LF Radio Signals on the Occasion of the Western Turkey Earthquake (Mw = 5.7) on May 19, 2011
Earthquake Precursors European Radio Network Radio Signal Analysis
2013/3/11
Since 2009 a network of VLF (20 - 60 kHz) and LF (150 - 300 kHz) radio receivers is operating in Europe in order to study the disturbances produced by the earthquakes on the propagation of these signa...
本文利用DEMETER卫星记录的变化磁场数据统计研究了2005—2009年北半球7级以上强震前后空间磁场的扰动特征.在震中±10°范围内利用震前2个月至震后1个月的5年同期观测的ELF/VLF[370~897 Hz]频段磁场功率谱密度数据构建了背景场,定义了表征空间磁场在地震时段相对于背景场的扰动幅度指标.统计研究发现26个强震中42%的地震主要表现为震前磁场扰度幅度逐渐上升,超过3倍标准差,随后...
电离层人工调制激发的下行ELF/VLF波辐射
电离层人工调制 ELF/VLF波辐射 全波解 HAARP实验
2011/11/22
通过大功率ELF/VLF调幅高频波对电离层进行加热,形成电离层虚拟天线,可以作为发射ELF/VLF波的一种有效手段.本文使用汪枫(2009)的调制加热模型,计算高频加热电离层产生的低频辐射源强度,采用全波解算法分析辐射的低频波向下传播过程中的衰减和反射问题,并采用HAARP实验参数,模拟出在海面上接收到的低频信号强度为PT量级,与实验数据一致.模拟结果表明,加热泵波功率、低频调制波频率、以及加热纬...
电离层人工调制激发的下行ELF/VLF波辐射
电离层人工调制 ELF/VLF波辐射 全波解 HAARP实验
2011/11/9
通过大功率ELF/VLF调幅高频波对电离层进行加热,形成电离层虚拟天线,可以作为发射ELF/VLF波的一种有效手段.本文使用汪枫(2009)的调制加热模型,计算高频加热电离层产生的低频辐射源强度,采用全波解算法分析辐射的低频波向下传播过程中的衰减和反射问题,并采用HAARP实验参数,模拟出在海面上接收到的低频信号强度为PT量级,与实验数据一致.模拟结果表明,加热泵波功率、低频调制波频率、以及加热纬...
Decrease of VLF transmitter signal and Chorus-whistler waves before l'Aquila earthquake occurrence
Decrease of VLF transmitter signal Chorus-whistler waves l'Aquila earthquake occurrence
2010/10/21
We investigate the VLF emissions observed by the Instrument Champ Electrique (ICE) experiment onboard the DEMETER micro-satellite. We analyze intensity level variation 10 days before and after the occ...
本文利用搭载在DEMETER卫星上的感应式磁力仪(Instrument Magnetometer Search-Coil, IMSC)探测数据分析了磁场甚低频(Very Low Frequency, VLF)波功率谱的空间分布.在排除地磁扰动影响(Dst≤-30 nT,Kp≥3,AE≥200 nT)的前提下,我们给出2007年不同季节,日侧和夜侧,磁场VLF波功率谱的全球分布的背景场探测和对应的统...
本文利用搭载在DEMETER卫星上的感应式磁力仪(Instrument Magnetometer Search-Coil, IMSC)探测数据分析了磁场甚低频(Very Low Frequency, VLF)波功率谱的空间分布.在排除地磁扰动影响(Dst≤-30 nT,Kp≥3,AE≥200 nT)的前提下,我们给出2007年不同季节,日侧和夜侧,磁场VLF波功率谱的全球分布的背景场探测和对应的统...
VLF-LF radio signals collected at Bari (South Italy): a preliminary analysis on signal anomalies associated with earthquakes
VLF-LF radio signals a preliminary analysis signal anomalies earthquakes
2009/12/14
At the beginning of 2002 an OmniPAL receiver was put into operation at the Department of Physics of Bari University (Southern Italy). The electric field strength of five VLF-LF signals transmitted fro...