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熟悉的地方有风景
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作者 《中华活页文选(高一年级版)》 2013年第8期55-56,共2页
也许我们—直向往着远方那“黄河之水天上来”的壮观风景,向往那“大江东去,浪淘尽千古风流人物”的豪迈风景,也许我们一直以来都认为美好的风景就在远方,海市蜃楼般飘渺迷人,流水落花般零丁飘落,于是我们毫不犹豫地舍弃身旁熟悉... 也许我们—直向往着远方那“黄河之水天上来”的壮观风景,向往那“大江东去,浪淘尽千古风流人物”的豪迈风景,也许我们一直以来都认为美好的风景就在远方,海市蜃楼般飘渺迷人,流水落花般零丁飘落,于是我们毫不犹豫地舍弃身旁熟悉的一切,一身风霜,一生沧桑,却在我们蓦然回首之际才发现多少美好的风景都在那灯火阑珊处。它们一直行走在生命的两旁,随时播种,随时开放。 展开更多
关键词 高中生 作文 语文学习 课外阅读
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Effect of non-Gaussian properties of the sea surface on the low-incidence radar backscatter and its inversion in terms of wave spectra by an ocean wave spectrometer 被引量:1
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作者 陈萍 黄萍 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第5期1142-1156,共15页
The principle of ocean wave spectrometers was first presented several decades ago to detect the directional wave spectrum with real-aperture radar(Jackson,1981). To invert wave spectra using an ocean wave spectrometer... The principle of ocean wave spectrometers was first presented several decades ago to detect the directional wave spectrum with real-aperture radar(Jackson,1981). To invert wave spectra using an ocean wave spectrometer,for simplicity,the hydrodynamic forcing and wave-wave interaction effect are neglected and a Gaussian slope probability density function(pdf) is used to calculate the normalized backscattering cross-section( σ 0) of the ocean surface. However,the real sea surface is non-Gaussian. It is not known whether the non-Gaussian property of the sea surface will affect the performance of the inversion of the wave spectrum if following existing inversion steps and methods. In this paper,the pdf of the sea surface slope is expressed as a Gram-Charlier fourth-order expansion,which is quasi-Gaussian. The modulation transfer function(MTF) is derived for a non-Gaussian slope pdf. The effects of non-Gaussian properties of the sea surface slope on the inversion process and result are then studied in a simulation of the SWIM(Surface Waves Investigation and Monitoring) instrument configuration to be used on the CFOSAT(China-France Oceanography Satellite) mission. The simulation results show that the mean trend of σ 0 depends on the sea slope pdf,and the peakedness and skewness coefficients of the slope pdf affect the shape of the mean trend of σ 0 versus incidence and azimuth; owing to high resolution of σ 0 in the range direction,MTF obtained using the mean trend of σ 0 is almost as accurate as that set in the direct simulation; in the inversion,if ignoring the non-Gaussian assumption,the inversion performances for the wave spectrum decrease,as seen for an increase in the energy error of the inverted wave slope spectrum. However,the peak wavelength and wave direction are the same for inversions that consider and ignore the non-Gaussian property. 展开更多
关键词 slope probability density of the sea surface ocean wave spectrometer NON-GAUSSIAN directionalwave spectrum energy error
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