查询词典 perigee

The following conclusions are drawn. 1 The orbit parameters that have relatively greater influence on the number and latitudinal distribution of annual occultation events are orbit inclination, orbit height, Right Ascension of Ascending Node and Argument of Perigee in turn. All four parameters have little impact on the longitudinal distribution of annual occultation events. 2 The orbit inclination of Transmitting Satellite and Receiving Satellite impacts both LEO－LEO occultation events number and their latitudinal distribution most. The number of occultation events reaches the maximum as the sum of the two inclination angles nears 180 degrees. The one that far away from 90 degrees of the two inclination angles determines the latitude range of the occultation events. 3 LEO－LEO occultation events number reaches a maximum when the heights of TS and RS are the same, and it reaches the maximum when the heights of TS and RS are 600 km . 4 The RAAN of TS and RS has a great influence on the LEO－LEO occultation number, but has little influence on occultation distribution.

结果指出：1对一年掩星事件数量及其纬度分布影响大的轨道参数依次是轨道倾角、轨道高度、升交点赤经和近地点角距；而这些参数对一年掩星事件的经度分布影响都不大；2发射卫星和接收卫星倾角之间的相互关系对掩星事件数量和纬度分布影响最大，两卫星倾角接近互补时掩星事件最多，两颗LEO卫星中与90°相差较大的倾角决定了LEO－LEO掩星事件的纬度分布范围；3发射卫星和接收卫星处于同一轨道高度时，LEO－LEO掩星事件数取得极大值，发射卫星和接收卫星都采用600 km的轨道高度，一年LEO－LEO掩星事件数最多；4 发射卫星和接收卫星升交点赤经的相互关系对LEO－LEO掩星事件数量影响很大，发射卫星和接收卫星升交点赤经之差为120°或240°时掩星事件数量最多，RAAN对掩星事件纬度和经度分布影响不大；5近地点角距对掩星事件数量和分布影响都不大。

At same heights but on different latitude areas, the density of the lower thermosphere is more intense at low latitude than that at high latitude. So does the satellite drag. Therefore, the perigee is lower at low latitude and it is lower by day than at night.

在高度相同情况下，中低纬区热层底部的大气密度比高纬区大，卫星受阻也就更大，从而卫星近地点的高度在中低纬区比高纬区要低、白天比夜间低。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。