Spread-F during the magnetic storm of 22 January 2004 at low latitudes: Effect of IMF-Bz in relation to local sunset time     

R G Rastogi  H Chandra  P Janardhan  Thai Lan Hoang  Louis Condori  T K Pant  D S V V D Prasad  B Reinisch 《Journal of Earth System Science》2014,123(6):1273-1285

The paper describes the results of spread-F at low latitude stations around the world during the magnetic storm starting at 0130 UT on 22 January 2004. The storm can be divided into two phases, first phase up to 1000 UT when interplanetary magnetic field IMF-Bz was highly fluctuating around a small positive value and the second phase after a sudden large southward turning of IMF-Bz at 1030 UT. The first phase produced strong spread-F at Jicamarca, Sao Luis, and Ascension Island and caused complete inhibition of spread-F at Thumba and Waltair in India. It generated weak spread-F at Ho Chi Minh City in Vietnam and strong spread-F at Hainan and Chung Li. The strong spread-F at Hainan and Chung Li were caused by the positive IMF-Bz during the first phase of the storm and not by the negative pulse of IMF-Bz at 1000 UT.  相似文献   

Graded-Density Reservoirs for Accessing High Stress Low Temperature Material States   总被引：1，自引：0，他引：1  

Raymond F. Smith  K. Thomas Lorenz  Darwin Ho  Bruce A. Remington  Alex Hamza  John Rogers  Stephen Pollaine  Seokwoo Jeon  Yun-Suk Nam  J. Kilkenny 《Astrophysics and Space Science》2007,307(1-3):269-272

In recently developed laser-driven shockless compression experiments an ablatively driven shock in a primary target is transformed into a ramp compression wave in a secondary target via unloading followed by stagnation across an intermediate vacuum gap. Current limitations on the achievable peak longitudinal stresses are limited by the ability of shaping the temporal profile of the ramp compression pulse. We report on new techniques using graded density reservoirs for shaping the loading profile and extending these techniques to high peak pressures.  相似文献   

Estimation of the Roll Hydrodynamic Moment Model of a Ship by Using the System Identification Method and the Free Running Model Test     

Hyeon Kyu Yoon Nam Sun Son Gyeong Joong Lee 《Oceanic Engineering, IEEE Journal of》2007,32(4):798-806

When a fast container ship or a naval vessel turns, accompanying roll motions occur. This roll effect must be considered in the horizontal equations of the motion of the ship to predict the maneuverability of the ship properly. In this paper, a new method for determining a model structure of the hydrodynamic roll moment acting on a ship and for estimating the hydrodynamic coefficients is proposed. The method utilizes a system identification technique with the data from sea trial tests or from free running model (FRM) tests. To obtain motion data that is applied to the proposed algorithm, an FRM of a large container ship was developed. Using this model ship, standard maneuvering tests were carried out on a small body of water out of doors. A hydrodynamic roll moment model was constructed utilizing the data from turning circle tests and a 20-20 zig-zag test. This was then confirmed through a 10-10 zig-zag test. It was concluded that a model structure of the hydrodynamic roll moment model could be established without difficulty through a system identification method and FRM tests.  相似文献   

Guocun landslide in a slate slope with dip structure on 27 March 2021 in Tonglu County,Zhejiang Province,China     

Wang  Fawu  Zhao  Zixin  Chen  Ye  Zhu  Guolong  Nam  Kounghoon  Ye  Zhenhua 《Landslides》2022,19(6):1435-1447

On 27 March 2021, a landslide with a volume of approximately 2?×?10⁴ m³ occurred in Guocun Village next to Kengheng road in Tonglu County, Zhejiang Province, China. The landslide caused no casualties as a result of timely road closures, because of the unusual noises detected early by local residents. The motion mechanism of the landslide was studied using video analysis. Slope cutting resulting from road construction might have been the major triggering factor for the landslide. The intrusion of magma and the uplift process of Huangshan led to the metamorphism of mudstone to easily fractured slate, and the brittle layered slate might have controlled the change of motion from transitional sliding to dry debris flow.

  相似文献   

Limited-Area Forecasting Model Based on Semi-Lagrangian Semi-Implicit Scheme Leading to Solving the Separable Elliptic Equations     

Batka  M.  Nam  T.T. 《Studia Geophysica et Geodaetica》2004,48(4):811-828

  相似文献   

Hydrocarbons in the Basement of the South China Sea (Vietnam) Shelf and Structural–Tectonic Model of their Formation     

Kerimov  V. Yu.  Leonov  M. G.  Osipov  A. V.  Mustaev  R. N.  Hai  Vu Nam 《Geotectonics》2019,53(1):42-59

Geotectonics - The paper considers the origin of hydrocarbon accumulations within the Pre-Cenozoic basement of the Vietnam shelf. It is shown that the formation of hydrocarbon deposits is...  相似文献   

Age and Growth of Southern Bluefin Tuna,Thunnus maccoyii,Based on Otolith Microstructure     

Ku  Jeong Eun  Lee  Sung Il  Kim  Doo Nam 《Ocean Science Journal》2021,56(4):413-423

Ocean Science Journal - Age and growth of southern bluefin tuna (SBT, Thunnus maccoyii) were estimated based on otoliths collected by Korean tuna longline vessels in the Atlantic and Indian Oceans...  相似文献   

Responses of chemically active and naturally fractured shale under time‐dependent mechanical loading and ionic solution exposure          下载免费PDF全文

Chao Liu  Son K. Hoang  Younane N. Abousleiman 《国际地质力学数值与分析法杂志》2018,42(1):34-69

In this paper, the analytical dual‐porosity dual‐permeability poromechanics solution for saturated cylinders is extended to account for electrokinetic effects and material transverse isotropy, which simulate the responses of chemically active naturally fractured shale under time‐dependent mechanical loading and ionic solution exposure. The solution addresses the stresses, fracture pore pressure, matrix pore pressure, fluid fluxes, ion concentration evolution, and displacements due to the applied stress, pore pressure, and solute concentration difference between the sample and the circulation fluid. The presented solution will not only help validate numerical simulations but also assist in calibrating and interpreting laboratory results on dual‐porosity dual‐permeability shale. It is recommended that the analytical solutions of radial and axial displacements be used to match the corresponding laboratory‐recorded data to determine shale dual permeability and chemo‐electrical parameters including membrane coefficient, ions diffusion coefficients, and electro‐osmotic permeability.  相似文献   

Changes in heat wave characteristics over Extremadura (SW Spain)     

Acero  Francisco Javier  Fernández-Fernández  María Isabel  Carrasco  Víctor Manuel Sánchez  Parey  Sylvie  Hoang  Thi Thu Huong  Dacunha-Castelle  Didier  García  José Agustín 《Theoretical and Applied Climatology》2018,133(1-2):605-617

Theoretical and Applied Climatology - Heat wave (HW) events are becoming more frequent, and they have important consequences because of the negative effects they can have not only on the human...  相似文献   

A nearly analytic symplectic partitioned Runge–Kutta method based on a locally one-dimensional technique for solving two-dimensional acoustic wave equations     

Chol Sim  Chunyou Sun  Nam Yun 《Geophysical Prospecting》2020,68(4):1253-1269

In this paper, we develop a new nearly analytic symplectic partitioned Runge–Kutta method based on locally one-dimensional technique for numerically solving two-dimensional acoustic wave equations. We first split two-dimensional acoustic wave equation into the local one-dimensional equations and transform each of the split equations into a Hamiltonian system. Then, we use both a nearly analytic discrete operator and a central difference operator to approximate the high-order spatial differential operators, which implies the symmetry of the discretized spatial differential operators, and we employ the partitioned second-order symplectic Runge–Kutta method to numerically solve the resulted semi-discrete Hamiltonian ordinary differential equations, which results in fully discretized scheme is symplectic unlike conventional nearly analytic symplectic partitioned Runge–Kutta methods. Theoretical analyses show that the nearly analytic symplectic partitioned Runge–Kutta method based on locally one-dimensional technique exhibits great higher stability limits and less numerical dispersion than the nearly analytic symplectic partitioned Runge–Kutta method. Numerical experiments are conducted to verify advantages of the nearly analytic symplectic partitioned Runge–Kutta method based on locally one-dimensional technique, such as their computational efficiency, stability, numerical dispersion and long-term calculation capability.  相似文献