专业外语-英语摘要

1、EffectsofwaveshapeonsheetflowsedimentTian-JianHsu,DanielM.A two-phase model is implemented to study the effects of wave shape on the transport of coarse-grained sediment in the sheet flow regime. The model is based on balance equation for the average mass, momentum, and fluctuation energy for both t

2、he fluid and sediment phases. Model simulations indicate that the responses of the sheet flow, such as the velocity profiles, the instantaneous bed shear stress, the sediment flux, and the total amount of the mobilized sediment, cannot be fully parameterized by quasi-steady free-stream velocity and

3、may be correlated with the magnitude of the local horizontal pressure gradient (or free-stream acceleration). A net sediment flux in the direction of wave advance is obtained for both skewed and saw-tooth wave shapes typical of shoaled and breaking waves. The model further suggests that at critical

4、valuesofthehorizontalpressuregradient,thereisafailureeventwithinthebed that mobilizes more sediment into the total bed shear stresses and the total sediment flux appear promising.本摘要是一篇信息型摘要(informative abstract)。全文采用了一般现在atwo-phasemodelisimplementedto themodel isbased modelsimulationsindicate/sugge

5、stthattheresponsessuchas;both and becorrelatedisobtained for thereWatertableresponsetoatidalagitationinacoastalaquifer: The Meyer-Polubarinova-Kochina theory revisitedThe linear potential model of Meyer and Polubarinova-Kochina (MPK) solves Laplaces equation in a quadrant, the vertical face of which

6、 is subject to a harmonic variation of hydraulic head induced by a tide. On the horizontal face of the quadrant a linear combination of the partial derivatives of the head with respect to time and with respect to the vertical Cartesian coordinate are linearly related. The fields of pore pressure (he

7、ad) and Darcian velocity, trajectories of marked particles, the oscillating phreatic surface and its upper envelop are obtained. Hydrograph in a piezometer located 60m from the shore line in a thick unconfined coastal aquifer (Oman) is interpreted by the analytical results of the model using the det

8、ected groundwater amplitude attenuated as compared with the tide amplitude. MPK method provides a potentially superior description to the Dupuit-Forchheimer method for tidally driven phreatic 本摘要是一篇信息型摘要(informative abstract)。全文采用了一般现在1）solve(problems)ina besubjectwithrespectbeinterpretedcomparedpro

9、videapotentiallysuperiordescriptionto Methodology to estimate the output of a dual solar-wind renewable energy system in JapanMiguel Esteban, Qi Zhang, Agya Utama, Tetsuo Tezuka, Keiichi Ni The potentially damaging effects of climate change make it imperative to develop zero-carbon energy systems an

10、d societies based on renewable energy sources that do not negatively affect the environment. However, these systems are often criticized for their intermittency, and the present paper proposes a method to analyze the true minimum capacity factor that can be expected from such a system based on a his

11、torical hourly estimation of the electricity produced by a given solarwind generating mix. A simulation was carried out to show how much energy could be produced for a sample future group of scenariosencompassingavariety of solarand windmixes,and theresultsshow that, with a 1:2 mix of solar to wind

12、energy, the system will always operate at least at 10% capacity from 10:00 to 16:00, as calculated using the meteorological conditions of the year 2001. This study also analyzes the land requirements necessary to implement such a solarwind energy system, highlighting the vast areas that would be necessary to be covered with wind turbines and solar panels if such a system were to supply the majority of the electricity demand in Japan.本摘要是一篇信息型摘要(informative abstract)