网格GIS体系结构及其实现技术

网格(grid)产生于20世纪90年代初,并且已经成长为高性能计算的一个新的研究热点,将掀起第三代IT浪潮。网格技术包括面向高性能计算的网格技术(计算网格)和面向信息服务的网格技术(服务网格)。网格GIS是将地理上分布、系统异构的各种计算机、空间数据服务器、大型检索存储系统、地理信息系统、虚拟现实系统等,通过高速互连网络连接并集成起来,形成对用户透明的虚拟的空间信息资源的超级处理环境,即网格地理信息系统。     

浅析晋城市1996年天气气候对蔬菜的影响及防治对策

浅析晋城市１９９６年天气气候对蔬菜的影响及防治对策石兰瑛（晋城市气象局０４８０００）何建和王卫萍（晋城市农牧局０４８０００）引言晋城市１９９６年天气气候对蔬菜生长发育影响很大，１９９６年４至７月气候异常，先后出现了两次长时间的低温阴雨天气，连续时间近...     

宁波金鸡山地区地震活动性及震害研究

在地震危险性分析的基础上，运用剪切波速法，逐步判别法等预测震害，这对唐山地震前缺乏标贯资料的高烈度城镇区，需补充预测时，提供了新的途径。     

风廓线雷达估算大气返回信号功率方法研究

基于风廓线雷达大气返回信号功率谱中噪声电平的估算方法,统计分析了北京延庆对流层风廓线雷达（CFL-08）2006年10～12月的探测数据。对该频段风廓线雷达环境噪声的空间和时间变化进行了分析,观测期间环境噪声在5km以下随高度递减,10月的平均环境噪声大于11月、12月的平均分布。给出目前风廓线雷达用信噪比估算大气返回信号功率的两种方法,并对两种方法进行了环境噪声的剔除,经过修正后的大气返回信号功率输出结果趋于一致。     

元代前期省域耕地面积重建（英文）

Reconstructing historical land use and land cover change(LUCC) at the regional scale is an important component of global environmental change studies and of improving global historical land use datasets. By analyzing data in historical documents, including military-oriented cropland(hereafter M-cropland) area, the number of households engaged in M-cropland(hereafter M-household) reclamation, cropland area, and the number of households, we propose a conversion relationship between M-cropland area and cropland area reclaimed by each household. A provincial cropland area estimation method for the Yuan Dynasty is described and used to reconstruct the provincial cropland area for AD1290. Major findings are as follows.(1) Both the M-cropland and cropland areas of each household were high in the north and low in the south during the Yuan Dynasty, which resulted from different natural conditions and planting practices. Based on this observation, the government-allocated M-cropland reclamation area to each household was based on the cropland area reclaimed by each household.(2) The conversion relationship between M-cropland and cropland areas per household showed conversion coefficients of 1.23 and 0.65 for the south and north, respectively.(3) The cropland area in the entire study area in AD1290 was 535.4×106 mu(Chinese area unit, 1 mu=666.7 m~2), 57.8% in the north and 42.2% in the south. The fractional cropland areas for the entire study area, north, and south were 6.8%, 6.6%, and 7.1%, respectively and the per capita cropland areas for the whole study area, north, and south were 6.7, 15.6, and 4.1 mu, respectively.(4) Cropland was mainly distributed in the middle and lower reaches of the Yellow River(including the Fuli area), Huaihe River Basin(including Henan Province), and middle and lower reaches of the Yangtze River(including Jiangzhe, Jiangxi, and Huguang provinces).     

怒江迪庆州陡坡耕地的改良和持续利用研究

滇西北的怒江、迪庆两州地处云南省高寒高山峡谷区，地形破碎而陡峻，耕地稀缺，陡坡种植业占有很高的比重。由于人口的增长，陡坡耕地仍将作为该地区的主要耕地长期存在。这种传统的耕种方式已对环境产生了深刻的负效应。本文根据其生存条件和利用现状就通过改良以取得持续利用的方向和途径作了初步探讨。     

商丘路河国土所巧用"四法"调处土地纠纷

商丘市国土资源局睢阳分局路河国土资源所针对农村土地纠纷不断增多、情况复杂等特点,巧用"四法"处理土地纠纷,取得了明显效果.今年以来,共受理土地纠纷23起,办结22起,办结率96%,回访当事人满意率100%."诚心法"处理土地纠纷有诚则灵.     

典型岩溶农业区地下水质与土地利用变化分析--以云南小江流域为例

以云南省泸西县小江典型岩溶农业流域为研究单元,利用1982和2004的地下水质数据及1982的航片和2004年的TM影像,在GIS支持下,研究其20年来的地下水质的时空变化及原因。结果表明：20年来流域地下水质在时间、空间分布上均发生较大的变化;流域耕地扩张和大量化肥、农药使用带来的非点源污染,造成地下水中的NH₄⁺、SO₄^2-、NO₃^-、NO₂^-、Cl^- 离子含量及pH值、总硬度、总碱度明显升高并超标,而林地减少或林地质量的下降,土地发生石漠化时,地下水中的Ca²⁺、HCO₃^- 浓度明显降低,同时,地下水各指标的空间变化与土地利用空间格局的变化表现出动态一致性。     

东北地区历史时期森林空间格局网格化重建方法研究(英文)

The spatially explicit reconstruction of historical land-cover datasets plays an important role in studying the climatic and ecological effects of land-use and land-cover change(LUCC). Using potential natural vegetation(PNV) and satellite-based land use data, we determined the possible maximum distribution extent of forest cover in the absence of human disturbance. Subsequently, topography and climate factors were selected to assess the suitability of land for cultivation. Finally, a historical forest area allocation model was devised on the basis of the suitability of land for cultivation. As a case study, we used the historical forest area allocation model to reconstruct forest cover for 1780 and 1940 in Northeast China with a 10-km resolution. To validate the model, we compared satellite-based forest cover data with our reconstruction for 2000. A one-sample t-test of absolute bias showed that the two-tailed significance was 0.12, larger than the significant level 0.05, suggesting that the model has strong ability to capture the spatial distribution of forests. In addition, we calculated the relative difference of our reconstruction at the county scale for 1780 in Northeast China. The number of counties whose relative difference ranged from-30% to 30% is 99, accounting for 74.44% of all counties. These findings demonstrated that the provincial forest area could be transformed into forest cover maps well using the model.     

基于100 nm砷化镓pHEMT工艺的C波段宽带低噪声放大器芯片

作为射电天文接收机系统的关键器件, 低噪声放大器的噪声和增益性能对接收机系统的灵敏度有重要影响. 采用100nm砷化镓赝配高电子迁移率晶体管(pseudomorphic High Electron Mobility Transistor, pHEMT)\lk工艺, 研制了一款可覆盖C波段(4--8GHz)的低噪声放大器(Low Noise Amplifier, LNA). 所设计的LNA采用3级共源级联放大拓扑结构, 栅极、漏极双电源供电. 常温下测试表明, 该LNA在4--8GHz频段内平均噪声温度为\lk60K, 在5GHz处获得最低噪声温度50K, 通带内增益($31\pm1.5$)dB, 输入输出回波损耗均优于10dB, 芯片面积为$2.1\times1.1$mm², 可以应用于C波段射电天文接收机以及卫星通信系统等.