排序方式： 共有11条查询结果，搜索用时 31 毫秒
1.
2.
Ernest Heymsfield 《地震工程与结构动力学》1999,28(12):1651-1667
The direct boundary integral equation technique is used to study in-plane surface amplification of in-plane seismic body waves for the case of an inhomogeneity in a bedrock half-space. In the studied soil configuration, a soil layer rests on a rock half-space which includes a rock inclusion. The rock inclusion considered is a semi-infinite horizontal rock layer in which its upper boundary borders the soil layer. Materials in the soil–rock configuration are considered viscoelastic except for the section of the rock half-space below the level of the rock inclusion which is considered elastic. A parametric study is performed to determine controlling factors for surface displacement due to in-plane body waves. The study investigates varying the stiffness and the thickness of the rock inclusion for a range of frequencies and wave incidence angles. Anti-plane waves for this type of soil-rock configuration have been addressed in a previous article by Heymsfield (Earthquake Engng. Struct. Dyn. 28 : 841–855 (1999)). Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
3.
4.
Chang Ki Kim Martin Stuefer Carl G. Schmitt Andrew Heymsfield Greg Thompson 《Pure and Applied Geophysics》2014,171(8):1963-1982
An ice microphysics parameterization scheme has been modified to better describe and understand ice fog formation. The modeling effort is based on observations in the Sub-Arctic Region of Interior Alaska, where ice fog occurs frequently during the cold season due to abundant water vapor sources and strong inversions existing near the surface at extremely low air temperatures. The microphysical characteristics of ice fog are different from those of other ice clouds, implying that the microphysical processes of ice should be changed in order to generate ice fog particles. Ice fog microphysical characteristics were derived with the NCAR Video Ice Particle Sampler during strong ice fog cases in the vicinity of Fairbanks, Alaska, in January and February 2012. To improve the prediction of ice fog in the Weather Research and Forecasting model, observational data were used to change particle size distribution properties and gravitational settling rates, as well as to implement a homogeneous freezing process. The newly implemented homogeneous freezing process compliments the existing heterogeneous freezing scheme and generates a higher number concentration of ice crystals than the original Thompson scheme. The size distribution of ice crystals is changed into a Gamma distribution with the shape factor of 2.0, using the observed size distribution. Furthermore, gravitational settling rates are reduced for the ice crystals since the crystals in ice fog do not precipitate in a similar manner when compared to the ice crystals of cirrus clouds. The slow terminal velocity plays a role in increasing the time scale for the ice crystals to settle to the surface. Sensitivity tests contribute to understanding the effects of water vapor emissions as an anthropogenic source on the formation of ice fog. 相似文献
5.
6.
Gultepe I. Heymsfield A. J. Fernando H. J. S. Pardyjak E. Dorman C. E. Wang Q. Creegan E. Hoch S. W. Flagg D. D. Yamaguchi R. Krishnamurthy R. Gaberšek S. Perrie W. Perelet A. Singh D. K. Chang R. Nagare B. Wagh S. Wang S. 《Boundary-Layer Meteorology》2021,181(2-3):227-265
Boundary-Layer Meteorology - Our goal is to provide an overview of the microphysical measurements made during the C-FOG (Toward Improving Coastal Fog Prediction) field project. In addition, we... 相似文献
7.
8.
Ernest Heymsfield 《地震工程与结构动力学》1999,28(8):841-855
The direct boundary integral equation technique is applied to determine the impact on surface amplification caused by an inhomogeneity in a bedrock half-space. The particular soil-rock configuration studied is one in which a soil layer rests on a rock half-space which includes a rock inclusion. The particular rock inclusion considered for this study is a semi-infinite rock layer with its upper boundary bordering the soil layer. Materials are considered viscoelastic except for the section of the rock half-space below the level of the rock inclusion which is considered elastic. A parametric study is performed to determine controlling factors for surface displacement due to a vertically incident shear wave. The study includes varying the stiffness and the thickness of the inclusion for a range of frequencies. Solutions from a one-dimensional analysis are compared with the results of a two-dimensional analysis in order to establish limits inside of which a two-dimensional analysis is required. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
9.
Two-dimensional scattering of SH waves in a soil layer underlain with a sloping bedrock 总被引：1，自引：0，他引：1
A two-dimensional analysis is applied to examine the effect that a sloping bedrock half-space has on the amplification of an anti-plane shear wave. The direct boundary integral equation method is used for the two-dimensional analysis. The particular soil–rock configuration investigated includes a homogeneous soil layer underlain by a sloping rock half-space. The rock half-space dips for a horizontal distance L and then becomes horizontal so that the overlying soil layer has a thickness H that remains constant from this point to infinity. The materials in the soil–rock configuration are considered viscoelastic except in the rock half-space below soil layer thickness H, which is considered elastic. This limitation in damping is due to the correction used for the truncation of the half-space boundary. Four cases are used to study the relationship between rock slope and surface displacement, vertical, 1:2, 1:4, 1:8. Surface displacements are determined for each of these cases for half-space incidence angles of 90, 75, and 60°. To allow for applicability to a wide range of problems, results are determined as a function of dimensionless parameters. In addition, solutions from a one-dimensional analysis are compared with the results of the two-dimensional analysis to establish limits outside of which a one-dimensional analysis suffices. 相似文献
10.
Gultepe I. Pardyjak E. Hoch S. W. Fernando H. J. S. Dorman C. Flagg D. D. Krishnamurthy R. Wang Q. Gaberšek S. Creegan E. Scantland N. Desjardins S. Heidinger A. Pavolonis M. Heymsfield A. J. 《Boundary-Layer Meteorology》2021,181(2-3):203-226
Boundary-Layer Meteorology - The objective of this work is to evaluate GOES-R (Geostationary Operational Environmental Satellites-R series) data-based fog conditions which occurred during the C-FOG... 相似文献