Results 41 to 50 of about 16,809 (204)
Dizhen xuebao, 2021 基于中国地震科学探测台阵在鄂尔多斯及周边地区布设的461个地震台为期2年的地震观测资料，采用背景噪声层析成像方法，研究获得了鄂尔多斯及周边地区5—46 s周期、分辨率高达0.3°×0.3°的瑞雷面波相速度分布图像。与基于程函方程的地震面波成像结果对比看出，噪声层析成像在较短周期具有明显的优势（5—16 s），可以获得更高分辨率的成像结果。短周期（5—10 s）的相速度分布揭示，河套盆地、太原盆地和运城盆地等均表现为显著的低速异常，表明这些盆地的新生代沉积较厚，临汾盆地为弱低速异常，推测其沉积层相对较薄 ...
Jing Liu +4 more
doaj +1 more source
Gravitational red-shift and deflection of slow light [PDF]
, 2008 We explore the nature of the classical propagation of light through media with strong frequency-dependent dispersion in the presence of a gravitational field.
A. N. Jordan +9 more
core +3 more sources
Models for Photon-photon Total Cross-sections [PDF]
, 1999 We present here a brief overview of recent models describing the photon-photon cross-section into hadrons. We shall show in detail results from the eikonal minijet model, with and without soft gluon summation.Comment: 7 pages, 5 figures, laTeX, requires ...
A. Grau +23 more
core +2 more sources
The focusing problem for the Eikonal equation [PDF]
Journal of Evolution Equations, 2003 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Angenent, S. B., Aronson, D. G.
openaire +2 more sources
Two approaches to the problem of ray seismic tomography
Геофизический журнал, 2015 Approximation of nonlinear geophysical medium as a linear one substantiates a transition to geometrical seismics based on geometric optics. Conditions, necessary and sufficient for application of geometrical optics bring possibility of linearization ...
T.A. Tsvetkova
doaj +1 more source
Elastic Differential Cross Sections for Space Radiation Applications [PDF]
, 2014 The eikonal, partial wave (PW) Lippmann-Schwinger, and three-dimensional Lippmann- Schwinger (LS3D) methods are compared for nuclear reactions that are relevant for space radiation applications.
Ford, William P. +4 more
core +3 more sources
Multiple surface wave tomography methods and their applications to the Tibetan Plateau
地球与行星物理论评, 2023 Surface wave tomography is a widely used geophysical method to measuring seismic velocity and anisotropy in the crust and upper mantle. This paper briefly reviewed the history of surface wave tomography, and summarized the principles and advantages of ...
Lun Li +3 more
doaj +1 more source
Seismic imaging of the critical zone of dolerite dykes at Cap Fréhel in Brittany (France)
Near Surface Geophysics, EarlyView.Abstract In June 2023, we measured ten near‐surface seismic profiles to image the critical zone of dolerite (diabase) dykes that cut the sandstone at Cap Fréhel in Brittany (France). Seismic ray tracing and inversion are used to determine the thickness of the regolith layer from first‐arrival P‐wave traveltimes.
M. Zillmer +4 more
wiley +1 more source
Fast Two-scale Methods for Eikonal Equations [PDF]
SIAM Journal on Scientific Computing, 2012 Fast Marching and Fast Sweeping are the two most commonly used methods for solving the Eikonal equation. Each of these methods performs best on a different set of problems. Fast Sweeping, for example, will outperform Fast Marching on problems where the characteristics are largely straight lines.
Chacon, Adam, Vladimirsky, Alexander
openaire +2 more sources
SDFs from Unoriented Point Clouds using Neural Variational Heat Distances
Computer Graphics Forum, EarlyView.We propose a novel variational approach for computing neural Signed Distance Fields (SDF) from unoriented point clouds. We first compute a small time step of heat flow (middle) and then use its gradient directions to solve for a neural SDF (right). Abstract We propose a novel variational approach for computing neural Signed Distance Fields (SDF) from ...
Samuel Weidemaier +5 more
wiley +1 more source