北宋中期耕地面积及其空间分布格局重建(英文)

To understand historical human-induced land cover change and its climatic effects, it is necessary to create historical land use datasets with explicit spatial information. Using the taxes-cropland area and number of families compiled from historical documents, we esti-mated the real cropland area and populations within each Lu (a province-level political region in the Northern Song Dynasty) in the mid-Northern Song Dynasty (AD1004-1085). The es-timations were accomplished through analyzing the contemporary policies of tax, population and agricultural development. Then, we converted the political region-based cropland area to geographically explicit grid cell-based fractional cropland at the cell size of 60 km by 60 km. The conversion was based on calculating cultivation suitability of each grid cell using the topographic slope, altitude and population density as the independent variables. As a result, the total area of cropland within the Northern Song territory in the 1070s was estimated to be about 720 million mu (Chinese area unit, 1 mu = 666.7 m2), of which 40.1% and 59.9% oc-curred in the north and south respectively. The population was estimated to be about 87.2 million, of which 38.7% and 61.3% were in the north and south respectively, and per capita cropland area was about 8.2 mu. The national mean reclamation ratio (i.e. ratio of cropland area to total land area; RRA hereafter for short) was bout 16.6%. The plain areas, such as the North China Plain, the middle and lower reaches of the Yangtze River, Guanzhong Plain, plains surrounding the Dongting Lake and Poyang Lake and Sichuan Basin, had a higher RRA, being mostly over 40%; while the hilly and mountainous areas, such as south of Nanling Mountains, the southwest regions (excluding the Chengdu Plain), Loess Plateau and south-east coastal regions, had a lower RRA, being less than 20%. Moreover, RRA varied with topographic slope and altitude. In the areas of low altitude (≤250 m), middle altitude (250-100 m) and high altitude (1000-3500 m), there were 443 million, 215 million and 64 million mu of cropland respectively and their regional mean RRAs were 27.5%, 12.6% and 7.2% respectively. In the areas of flat slope, gentle slope, medium slope and steep slope, there were 116 million, 456 million, 144 million and 2 million mu of cropland respectively and their regional mean RRAs were 34.6%, 20.7%, 8.5% and 2.3% respectively.     

近实时公共气象服务分析图网站发布

给出一种基于开源IDV工具构建气象产品网站发布平台的设计思路和实现方法。近实时公共气象服务分析图将使用人员定位于浏览器端县乡级气象、农技、公众群体,突出分析图的时空分级覆盖、耕作层气象服务、山地气象服务和灾害气象服务。通过内容、时间、区域以及表现形式4个方面的分解,描述了网站的设计原理。通过本体技术实现气象要素向气象知识的过渡。通过图形产品的静态和动态层分别处理,提高了二维和三维图形产品的生成速度。构建形成的气象产品发布平台已经在多个网站得到应用并得到好评。     

能见度观测现状浅谈

针对当前能见度操作中的景况,提出能见度观测中被忽视的几个突出问题,旨在提高能见度观测的正确度.     

电源避雷器安装应注意的问题

该文分析在防雷工程施工安装避雷器的选型、安装位置确定中应注意的问题。     

X波段双极化多普勒天气雷达极限降水的估计能力

首先分析了X波段双极化多普勒天气雷达降水估计的误差来源及其影响,然后分析了信比、积累阶数对降水估计精度的影响,明确雷达系统本身的测量误差所能达到的理想程度,结果表明在双通道的积累次数M=64,信噪比SNR=10dB的条件下差分反射率的σ(ZDR)=0.32dB,则相应R(Z,ZDR)的降水估计精度最好能达到44%,同样条件下差分相位的σ(ΦDP)=0.08°,那么在降水率R=50mm/h时R(KDP)的降水估计精度最好能达8.6%。     

地市级电视天气预报节目演播稿的撰写技巧

从撰写节目演播稿的内容出发,将天气预报节目的"科学性"和"服务性"结合起来,向大众宣传气象科技,提高气象的社会地位。     

地籍管理信息系统工程建设之管见

结合多年的工作实践经验,介绍了信息时代地籍管理的有关知识以及评价一个CMIS工程的准则,对我国当前地籍管理信息系统工程建设的几个非技术问题进行了探讨。     

混合热源与热泵联动空调技术及其在天津"975"工程中的应用

混合热源与热泵联动空调技术以天然、廉价和低品位的资源为主,以高品位资源为尖峰负荷的系统能源配置设计新方法,实现以单投入多功能的新型能源利用方式替代多投入单功能传统的能源利用方式,使建筑物的空调系统具有经济、节能与环保等特点.该项技术能较好地应用于能源获取难度大、单一冷热源不能满足要求的工程.在天津"975"工程供暖及制冷系统中的应用结果表明:混合热源与热泵联动空调技术成功地解决了系统的冷热源、热(冷)负荷需求大等难题,具有明显的环境与经济效益.     

松辽盆地西北部富裕地区黑富地1井二叠系烃源岩地球化学特征

正近年来松辽盆地及外围二叠系作为潜在的勘探层系越来越被重视,许多油气地质调查工作者针对烃源岩特征开展了大量的调查研究工作,认为松辽盆地及外围二叠系分布范围广、沉积厚度大、暗色泥岩发育,具有较高的油气勘探前景(陈树旺等,2013;朱志立等,2017)。但由于松辽盆地内的二叠系被上覆地层所覆盖,埋藏深度大,揭示二叠系     

我国北疆地区1961—2017年冻融指数的变化趋势

利用我国北疆地区49个主要气象站1961-2017年的逐日平均气温观测值计算了年冻融指数,并分析其变化趋势及分布特征。结果表明：北疆地区冻结指数出现明显的下降趋势,下降速率为51.6℃·d·（10a）^-1。冻结指数的范围在509~2 304.9℃·d之间,平均值为1 240℃·d。北疆地区融化指数出现明显上升趋势,上升速率为73.9℃·d·（10a）^-1。融化指数的范围在526.4~4 531.1℃·d之间,平均值为3 516℃·d。冻结指数表现出在经纬度和海拔较低的准噶尔盆地和伊宁地区较小,在海拔高的高山地区如阿尔泰山和天山山脉较大;融化指数与之相反。北疆地区冻结指数受经纬度及海拔的综合影响,融化指数则主要受海拔影响;年平均气温和冻融指数有非常强的线性关系。