连续台风时期香港区域的水汽变化分析

利用香港卫星定位参考站网GNSS观测数据,提取强热带风暴"塔拉斯"与热带风暴"洛克"影响期间各测站天顶方向对流层延迟,反演香港区域大气可降水量;根据香港区域49个天文台气象站提供的实测降雨量数据,分析大气可降水量与实际降雨量的相关性,以及两次台风对香港区域水汽时空分布的不同影响。结果表明,大气可降水量在台风影响前期均上升,在大量降雨后回落,但在连续台风的间歇期间,仍高于台风来临前的水平;水汽累积是大量降雨的前提条件,当水汽累积量相近时,水汽累积时长与累积降雨量呈正相关;台风期间大气可降水量值超过65 mm的区域面积与台风等级相关,台风路径对局部水汽分布有一定的影响。     

A CASE STUDY ON CONCENTRATION AND DECENTRALIZATION：BEHAVIOR AND DYNAMIC MECHANISM OF SPATIAL EVOLUTION IN METROPOLITAN AREA，NANJING，CHINA

In rapid socio-economic development,the process of concentration and dispersal of various elements tends to be more dramatic,tremendously influencing the shaping and transformation of the space in metropolitan area.Survey of spatial concentration and decentralization has thus become a basic method in examining metropolitan spatial evolution.In this research,three elements were selected as the essential indicators of the process:demographic density distribu-tion,employment density distribution and business office location.Performance of these elements in Nanjing City was exam-ined historically.As Nanjing City could be regarded as a representative of metropolitan areas in China,its situation large-ly suggestes the general characteristics in similar areas of China.Hence based on the investigation of Nanjing City,four general implications were highlighted.First ,metropolitan areas in China are in a violent process and shift of spatial concentra-tion and decentralization.Second,from now to at least the near future,concentration will continue to be the central fea-ture.Third,the landscape of metropolitan areas basically exhibits a dual structure character.The gap in environmental and ecological qualities among different districts will continue for a long time.Fourth,Central Business District (CBD) is playing an important role in helping to convert the traditionally single-centered city structure into a polycentric one.     

SPATIAL—TEMPORAL VARIATION OF HEAVY METAL ELEMENTS CONTENT IN COVERING SPIL OF RECLAMATION AREA IN FUSHUN COAL MINE

Grid method is employed for sampling covering soil at the test field,which is reclamation area filled by coal mining wastes for cropland in the Fushun coal mine,Liaoning Province,the Northeast China.The soil samples are taken at different locations,including three kinds of covering soil,three different depths of soil layers and four different covering ages of covering soil.The spatial-temporal variation of heavy metal element content in reclamation soil is stud-ied.The results indicate that the content of heavy metal elements is decreasing year after year,the determinant reason why the content of heavy metal elements at 60cm depth layer is higher than that at 30cm depth layer and surface is fertiliz-er and manure application;the metal elements mainly come from external environment;there is no metal pollution coming from mother material (coal mining wastes)in plough layer of covering soil.     

试论新世纪地理信息科学的发展

本文重点分析了当前国内外地理信息科学的形成与发展趋势和地理信息科学不断发展的历程 ,提出近期发展的前沿 ,以及当前地理信息产业化面临的一些重要问题。最后提出对地理信息科学发展的意见。     

Discovery of 13 New Variable Stars in the Field of the Open Cluster NGC 2168 （M35）

A wide-field time-series CCD photometric survey of variable stars in the field of the open cluster NGC 2168 was carried out using the BATC Schmidt telescope. In total 13 new variable stars are discovered with three W UMa systems, one EA type and two EB type eclipsing binaries (one of them could be a W UMa system), and seven pulsating stars including three candidates of δScuti stars.     

Influence of the Choice of Core-Envelope Transition Point on the Binary Merger of Two Main-sequence Components

We have studied the influence of different choices of core-envelope transition point on the final merger of contact binaries with two main-sequence components. A binary of 1.00 + 0.90M⊙ with an initial orbital period of 0.35d is examined. The mass fraction of the primary mixed with the matter of the secondary, qmix, determined by the chosen core-envelope transition point, ranges from 0.04 to 1.00 in our analysis. If as qmix< 0.8, none of the