地图数学定义的研究

在地图内容和形式数学表示的基础上研究了地图的数学定义。由于引入隐式地图和变换条件，故所有储存地图信息的载体均可属于地图的范围，从而使地图定义获得了广义的解释和精确的表达     

电子新技术条件下的地图设计

电子出版系统的参与与电子地图的兴起，是当今地图制图新技术的重要表现。本文讨论了这一新技术对现代地图学的影响，并分析了新技术条件下现代地图设计的特点     

Theory of satellite ground-track crossovers

The fundamental geometry of satellite ground tracks and their crossover problem are investigated. For idealized nominal ground tracks, the geometry is governed by a few constant parameters whose variations lead to qualitative changes in the crossover solutions. On the basis that the theory to locate crossovers has not been studied in sufficient detail, such changes are described in regard to the number of crossover solutions in conjunction with their bifurcations. Employing the spinor algebra as a tool for establishing the ground-track crossing condition, numerical methodologies to locate crossovers appearing in general dual-satellite ground-track configurations are also presented. The methodologies are applied to precisely determined orbital ephemerides of the GEOSAT, ERS-1, and TOPEX/POSEIDON altimeter satellites. Received: 19 November 1996 / Accepted: 12 May 1997     

A new gravity map, a new marine geoid around Japan and the detection of the Kuroshio current

About half a million marine gravity measurements over a 30^∘×30^∘ area centered on Japan have been processed and adjusted to produce a new free-air gravity map from a 5′×5′ grid. This map seems to have a better resolution than those previously published as measured by its correlation with bathymetry. The grid was used together with a high-degree and -order spherical harmonics geopotential model to compute a detailed geoid with two methods: Stokes integral and collocation. Comparisons with other available geoidal surfaces derived either from gravity or from satellite altimetry were made especially to test the ability of this new geoid at showing the sea surface topography as mapped by the Topex/Poseidon satellite. Over 2 months (6 cycles) the dynamic topography at ascending passes in the region (23^∘47^∘N and 123^∘147^∘E) was mapped to study the variability of the Kuroshio current. Received: 15 July 1994 / Accepted: 17 February 1997     

哀牢山-红河左旋走滑剪切带构造抬升时间序列的裂变径迹证据

对采自红河断裂带元阳—嘎洒段的４个片麻岩和糜棱岩样品中的磷灰石进行裂变径迹（ＦＴ）测年，得到５．６１～１０．６４Ｍａ的年龄范围。结果表明，ＲＲＦＺ段磷灰石ＦＴ年龄有从东南向西北变新的趋势。结合已有的钾长石多重扩散域（ＭＤＤ）模式结果，得到该段１５０℃至１１０℃温度范围的冷却过程（冷却速度为３．４～９．４５℃／Ｍａ）。ＦＴ结果反映的特征与南海盆地得到的１５Ｍａ时断裂带所受力的转换的结果是一致的     

水库流域入库洪水预报误差分析

由于受水库枢纽工程的影响，使得反推计算的入库流量本身就存在较大的误差，从而增加了入库洪水预报模型研制的难度，影响了这时预报精度的考核。通过对全国诸多水电厂水库流域实时洪水预报的实践，对其入库洪水预报中存在的误差原因及解决方法进行了科学的分析和阐述，以指导实时预报。     

基于GIS的山区年均温分布模拟与制图

针对某些下垫面复杂而气象站(哨)有限的山区,用地理信息系统(GIS)和气温推算数学模型相结合,来获取全域的年均温分布栅格图和等值线矢量图。以龙游县为例,说明了该方法从数学模型、因素图输入、图层格式转换、图幅叠置分析等一系列技术步骤。     

全国地质灾害趋势预测及预测图编制

区域地质灾害预测是地质灾害研究的难题。本文运用基于地理信息系统的风险评价方法对这一问题进行了探讨。将全国剖分为２７００个单元，对地质灾害进行现状评价，并与已数字化的地质灾害图件进行单要素叠加，编制了全国地质现状等值线图，在现状评价基础上，对地质灾害进行趋势预测，将降雨条件、区域地震活动、区域地壳稳定程度、区域岩组条件和人类工程活动等作为区域地质灾害演变的因素，运用模糊综合评判模型进行综合评判，编制了１：６００万中国地质灾害趋势预测图。     

The Uplift of the Longmenshan Thrust Belt and Subsidence of the West Sichuan Foreland Basin

Based on fission track dating of apatite, and measurement of vitrinite reflectance of rock samples from the Longmenshan (Longmen Mountain)area and the West Sichuan foreland basin and computer modelling it is concluded that (l)the Songpan-Garze fold belt has uplifted at least by 3-4 km with an uplift rate of no less than 0.3-0.4 mm/a since 10 Ma B.P.; (2) the Longmenshan thrust nappe belt has uplifted at least by 5-6 km with an uplift rate of more than 0.5- 0.6 mm /a since 10 Ma B.P.; (3) the Longmenshan detachment belt has uplifted by 1 - 2 km at a rate of 0.016-0.032 mm/a since 60 Ma B.P.; (4) the West Sichuan foreland basin has uplifted by 1.7-3 km at a rate of 0.028-0.05 mm/a since 60 Ma B.P.; (5) the uplift rate of the area on the west side of the Beichuan-Yingxiu-Xiaoguanzi fault for the last 10 Ma is 40 times as much as that on its east side; (6) the uplifting of the the Songpan - Garze fold belt and the subsidence of the West Sichuan foreland basin 60 Ma ago exhibit a mirro-image correlation, i.e     

Radon,Lung Cancer Risk and Environmental Geology in Gejiu Area

The incidence of lung cancer in the Gejiu area of Yunnan Province ranks the first in the world.The radon level(indoor,soil) was measured in the Gejiu area by the SSNTD method from 1990 to 1996,The result indicates an extensive high-level of indoor radon in that area though U and Th are lower in local limestones,The indoor radon level of houses located in the geologic fault zone is 6 times high that 2km far from the fault zone.The reason probably is that the radon level of soil in the fault is 6-8 times high that 1 km far from the faults.our data indicate that a lower range of radon levels,0-100Bq.m^-3,exists in healthy families.However,a higher radon level,over 800 Bq.m^-3,is often found corresponding to that of cancer patients‘ homes(the house-owners are suffering from either lung cancer or leukaemia or liver cancer),Obviously,an increase in lung cancer incidence follows an increase in indoor radon level,The risk of cancer induced by indoor radon is no longer an inference,but a fact.