土壤水的储存

与地表水的蓄水相反,水文研究过程中对降水在土壤中暂时蓄水量和蓄水时间考虑得很少。这是因为获得数据比较困难之故。现在,应用奥地利耕水试验设施进行的一系列观测,都为求某些土壤水的蓄水系数提供了可能。土壤中水的蓄存及消耗与地表水域的情况相似。当然,土壤的水力过程不易观察到。     

Simulations of Titan's brightness by a two-dimensional haze model

We have used a 2-D microphysics model to study the effects of atmospheric motions on the albedo of Titan's thick haze layer. We compare our results to the observed variations of Titan's brightness with season and latitude. We use two wind fields; the first is a simple pole-to-pole Hadley cell that reverses twice a year. The second is based on the results of a preliminary Titan GCM. Seasonally varying wind fields, with horizontal velocities of about 1 cm sec-1 at optical depth unity, are capable of producing the observed change in geometric albedo of about 10% over the Titan year. Neither of the two wind fields can adequately reproduce the latitudinal distribution of reflectivity seen by Voyager. At visible wavelengths, where only haze opacity is important, upwelling produces darkening by increasing the particle size at optical depth unity. This is due to the suspension of larger particles as well as the lateral removal of smaller particles from the top of the atmosphere. At UV wavelengths and at 0.89 micrometers the albedo is determined by the competing effects of the gas the haze material. Gas is bright in the UV and dark at 0.89 micrometers. Haze transport at high altitudes controls the UV albedo and transport at low altitude controls the 0.89 micrometers albedo. Comparisons between the hemispheric contrast at UV, visible, and IR wavelengths can be diagnostic of the vertical structure of the wind field on Titan.     

Homochirality as the signature of life: the SETH Cigar

A characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. It is therefore suggested that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality (SETH). A novel miniaturized space polarimeter, called the SETH Cigar, is described which could he used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. It is believed that homochirality will be found in the subsurface layers on Mars as a relic of extinct life.     

可视化技术在遥感图像处理系统中的应用

本文在简述可视化技术及可视化软件平台的基础上,将可视化技术引入到遥感图像处理系统设计中,给出了可视化遥感图像处理系统的基本框架,并分析探讨了可视化处理系统中涉及的若干关键技术,指出了可视化遥感图像处理在开放性,透明性,构造性及实用性等方面具有明显的优越性。     

APPLICATION OF THE TRRL FLOOD ESTIMATION MODEL IN HYDROLOGICAL FORECASTING FOR CATCHMENTS WITH LIMITED DATA A CASE STUDY

１ＩＮＴＲＯＤＵＣＴＩＯＮＯｎｔｈｅｍｏｒｎｉｎｇｏｆ３０ｔｈＪａｎｕａｒｙ１９９２,ａＮａｉｒｏｂｉｂｏｕｎｄｐａｓｅｎｇｅｒｔｒａｉｎｆｒｏｍＭｏｍｂａｓａｏｎｔｈｅｍａｉｎｌｉｎｅｄｅｒａｉｌｅｄｉｎｔｏａｎｅｍｂａｎｋｍｅｎｔｔｈａｔｈａｄｂ...     

地理信息系统(GIS)及其应用

１引言地理信息系统（ＧｅｏｇｒａｐｈｉｌＩｎｆｏｒｍａｔｉｏｎＳｙｓｔｅｍ）简称ＧＩＳ,是指各类空间数据（反映整个地球表面或深部、整体或区域之资源、环境的现势和变迁）和表达其特征的属性数据,以及这些数据在计算机中的采集、存储、管理、建模、输出的技术系...