基于多源时空大数据的区际迁徙人群多层次空间分布估算模型——以COVID-19疫情期间自武汉迁出人群为例

已有研究很少关注区际迁徙人群在不同尺度上空间分布的动态估算问题。COVID-19疫情爆发以来,坚决防止疫情扩散成为社会最紧迫的事情。在2020年1月23日武汉“封城”前夕,已有500多 万人离开了武汉,快速准确地推算这部分人群的去向,可以为防止疫情扩散和制定防疫决策提供科学依据。本文以此为例,基于开源腾讯位置请求大数据、百度迁徙大数据、土地覆盖数据等多源地理时空大数据,提出一种区际迁徙人群多层次空间分布动态估算模型,用于推算2020年除夕 （2020年1月24日）之前从武汉流入湖北省内各地的人群数量及其分布特征。结果显示：① 春节时段湖北省各地级市农村地 区人群增加数量占人群变化总量的比例平均达124.7%,从武汉市迁入各地级市的人群中至少51.3%流入农村地区;② 区县尺 度人群变化总量的空间分布呈现3个圈层结构：第一圈层为疫情核心区,包括武汉及其周边地区,以人群流出为主;第二圈层为 重点关注区,包括黄冈、黄石、仙桃、天门、潜江、随州、襄阳,以及孝感、荆门、荆州和咸宁的部分地区,以人群总量和农村地区人 群数量大幅增加为主;第三圈层为次级关注区,包括湖北西部宜昌、恩施、神农架和荆门部分地区,以人群小幅流入为主。最后,建议湖北省内,尤其是位于第二圈层内的区县,应高度关注农村地区人群的疫情防控。此研究成果在2~3天完成,显示大数据是可以快速地响应重大公共安全事件,为决策的制定提供一定支持的。     

POSSIBLE HYDROGEOCHEMICAL PRECONDITIONS FOR KASHIN－BECK DISEASE IN TRANSBAIKALIA

ＰＯＳＳＩＢＬＥＨＹＤＲＯＧＥＯＣＨＥＭＩＣＡＬＰＲＥＣＯＮＤＩＴＩＯＮＳＦＯＲＫＡＳＨＩＮ－ＢＥＣＫＤＩＳＥＡＳＥＩＮＴＲＡＮＳＢＡＩＫＡＬＩＡ￥ＺａｍａｎａＬｅｏｎｉｄＶａｓｉｌｅｖｉｃｈ（ＣｈｉｔａＩｎｓｔｉｔｕｔｅｏｆＮａｔｕｒａｌＲｅｓｏｕ...     

Industrial green spatial pattern evolution of Yangtze River Economic Belt in China

We use the directional slacks-based measure of efficiency and inverse distance weighting method to analyze the spatial pattern evolution of the industrial green total factor productivity of 108 cities in the Yangtze River Economic Belt in 2003–2013.Results show that both the subprime mortgage crisis and ‘the new normal' had significant negative effects on productivity growth,leading to the different spatial patterns between 2003–2008 and 2009–2013.Before 2008,green poles had gathered around some capital cities and formed a tripartite pattern,which was a typical core-periphery pattern.Due to a combination of the polarization and the diffusion effects,capital cities became the growth poles and ‘core' regions,while surrounding areas became the ‘periphery'.This was mainly caused by the innate advantage of capital cities and ‘the rise of central China' strategy.After 2008,the tripartite pattern changed to a multi-poles pattern where green poles continuously and densely spread in the midstream and downstream areas.This is due to the regional difference in the leading effect of green poles.The leading effect of green poles in midstream and downstream areas has changed from polarization to diffusion,while the polarization effect still leads in the upstream area.     

基于分形维度法的都市区城市蔓延分析——以广佛为例

根据1957与1982年两个时期的地形图并结合1995与2008年的遥感卫星影像提取城镇建设用地专题信息,利用ArcGIS建立广佛都市区城镇建设用地数据库,采用分形维度的计算方法,对广佛都市区城市蔓延的情况进行测度和分析。结果表明广佛都市区三个发展阶段城镇建设用地面积增长速度并不均匀,具有加速发展的特点。四个测度年份的分形维数分别为1.645 4,1.628 5,1.558 6和1.527 0,均在1～2之间,分形维数呈递降趋势,总体下降了0.118 4,城市发展模式由紧凑型逐渐向松散型演变,存在城市蔓延情况,而且城市发展模式以年均0.14%的速度从紧凑型向松散型演变。广佛都市区城市蔓延的地域分异较为明显,具有较强的空间集聚性和中心向心性,广州和佛山毗邻地区以及中心城区是城市蔓延的活跃区和集中区,1982-1995年间研究区内蔓延速度比1995-2008年间要快。通过深入分析发现,经济快速发展、城市人口的持续增长、交通道路网络的建设是广佛都市区快速扩张和城市蔓延的基本动力因素之一,开发区土地扩张,进一步加剧了无序扩张和城市蔓延。     

基于GIS新冠智能体仿真模型及应用——以广州市为例

2019年12月湖北省武汉市出现了新型冠状病毒肺炎疫情。新型冠状病毒传播力强,导致全国甚至全世界范围都出现新型冠状病毒疫情。为了刻画新型冠状病毒在城市内部的传播方式,本文基于个体在城市中的行为和社会关系,融合了复杂网络理论和GIS技术构建了新型冠状病毒智能体仿真模型。该模型以广州市为研究对象,通过马尔科夫链蒙特卡洛方法拟合参数,实现了对广州市疫情的准确回顾。结果表明,模型精度良好,其中MAPE为0.17。智能体模型具有良好的适用性。因此可以模拟境外输入病例对城市疫情发展的影响。智能体模型标记了个体的时空位置和社会关系,因此本文还提出一种通过智能体模型进行流行病学调查的方式,该方式相较于传统流行病调查更加便捷,效率更高。然后根据模拟分析结果,为城市防控疫情提供有价值的决策信息。最后建议市民,如果城市再次暴发疫情,不必恐慌,疫情会在14~20 d被控制,但是要提高自我防护意识,做好自我保护。     

荆州地区自动气象站网超短波超视距数据通信

本文介绍了荆州地区自动气象站网的组成及其设计思想。通过对无线电波传播损耗的理论分析和研究,论述了超短波超规距数据通信的可行性,提出了通信系统的改进方法,为平原地区组建无线电通信网络提供了新思路。     

西部新型智慧城市规划与建设模式探析——以兰州市为例

针对西部欠发达地区新型城镇化发展面临的问题,通过总结地处西部欠发达地区的兰州市在新型智慧城市规划建设框架体系和重点领域,以及兰州市在新型智慧城市建设方面所取得的阶段性成果,提出在大数据背景下兰州新型智慧城市规划建设模式,即以下三方面:一是以政府战略为主导的顶层设计;二是注重智慧民生服务与社会治理;三是开创综合创新型智慧新区建设。最后针对目前兰州新型智慧城市建设阶段,提出今后持续改进的3个着力点:一是建立以"大数据"为依托的新型智慧城市建设战略,二是打破"信息孤岛",加快提升"互联网+政务服务"水平,三是建立"绿色、协调、可持续"的低碳发展构想。     

GIS网络多媒体教学系统的设计与运行

为了适应21世纪课程教材《地理信息系统概论》的教学需要,以及该学科面向社会普及的发展趋势,南京大学在Authorware开发环境下完成了GIS网络多媒体教学系统的设计与实现,并通过ActiveX插件的形式将Authorware课件与前期建立的GIS教学网站有机地结合起来,形成面向网络的GIS多媒体教学系统。该系统将学生置于网络交互状态下,在仿真环境中了解并掌握GIS系统的基础知识、基本操作以及应用特色,最终实现GIS教学手段的现代化,达到提高GIS科技普及程度的目标。     

地图学网站的设计与实现

随着计算机与互联网技术的发展与应用,古老的地图正在发挥着越来越重要的作用。为了普及地图学知识,增加人们对地图的了解与应用,适应网络化教育发展的需要,我们建立了专业性的“地图学网站”。本文介绍了该地图学网站的主要内容、功能设计与实现方法,对地图学网站及网络地图的设计与实现进行了初步的探索。     

Territorial suitability assessment and function zoning in the Jiuzhaigou earthquake-stricken area

An earthquake in the Jiuzhaigou area caused numerous secondary disasters, such as rolling stones, land collapse, landslides and debris flow, which badly affected the safety of human settlements and influenced the spatial layout of the post-disaster reconstruction. Therefore, carrying out assessments of land and identifying a suitable zone for human habitats were very important. This research creates the territorial suitability assessment and function zoning conceptual model in the earthquake-stricken area, and the new methods of the territorial suitability evaluation system were used to divide the spatial functional zones of the earthquake stricken area, which provide a theoretical guidance and decisionmaking basis for the reconstruction of the disaster area. The results showed that:(1) The Jiuzhaigou earthquake-stricken area comprises of an ecological area that has a high level of importance to the ecosystem. In the earthquake-stricken area, 65% of national land is at an altitude of 3000-4000 m, and therefore not suitable for a high level of intensive reconstruction, but reconstructed in an eco-friendly manner.(2) The zone suitable for reconstruction comprises mainly of the river valley and the flat terrain of western parts. The land with low suitability is mainly located on steep terrain, such as highmountains and low gullies. The geographic and geomorphic conditions limit the spread of a suitable reconstruction zone.(3) The earthquake-stricken area mainly comprises of a tourism industry gathering area, population gathering area, agriculture and animal husbandry development area, and ecological preservation area with areas of 76 km~2, 44 km~2, 1591 km~2 and 7512 km~2, respectively. Scientifically zoning the reconstruction areas using scientific evaluation may provide guidance for the location of reconstruction sites.     

Using impervious surfaces to detect urban expansion in Beijing of China in 2000s

The change of impervious surface area(ISA) can effectively reveal the gradual process of urbanization and act as a key index for monitoring urban expansion. Experiencing rapid growth of the built environment in the 2000 s, urban expansion of Beijing has not been fully characterized through ISA. In this study, Landsat TM images of Beijing in 2001 and 2009 were obtained, and the eight-year urban expansion process in Beijing was analyzed using the ISA extracted by means of the vegetation-imperious surface-soil(V-I-S) model. From the spatial variation in ISA, the ring structure of urban expansion in Beijing was significant during the study period, with decreasing urban density from the city center to the periphery. In the ring road analysis, the most dramatic changes of ISA were found between the fifth ring and the sixth ring. This area has experienced the most new residential development, and is currently the main source of urban expansion. The typical profile lines revealed the directional characteristics of urban expansion. The east-west profile was the most urbanized axes in Beijing, while ISA change in the east-north profile was more significant than in the other five profiles. Moreover, the transition matrix of ISA levels revealed an increase in urban density in the low density built areas; the Moran′s I index showed a clear expansion of the central urban area, which spread contiguously; and the standard deviational ellipse indicated the northeast was the dominant direction of urban expansion. These findings can provide important spatial control guidelines in the next round of national economic and social development planning, overall urban and rural planning, and land use planning.     

Water Intake and Utilization in Mithun (Bos frontalis):Effect of Environmental Temperature, Rearing System and Concentrate Feed Supplement

Seasonal and sexual variations as well as the effect of dry feed supplement on total drinking water intake and its utilization were observed in mithun (Bos frontalis)-a semi-wild animal found in North Eastern Hill Region (NEHR) of India. In a completely randomized design, twelve adult mithuns (B. frontalis) as per their sex and body weight were assigned in two different rearing systems (free grazing and free grazing with dry concentrate feed supplementation), and ten growing male mithuns as per their body weight assigned in two different levels of dry concentrate feed supplementation (1.0 kg and 2.0 kg dry concentrate feeds on green forage based diet) and in two different seasons (summer and winter). It was observed that the environmental temperature had a significant effect on drinking water intake by mithuns. Drinking water consumption (per unit of body weight) was significantly (P < 0.05) higher in summer than in winter. Supplementation of concentrate feed on free grazing animals resulted in increase in water consumption. Total water consumption (drinking as well as performed water) was found to be 15.18 litres per 100 kg body weight by growing mithun. Feed dry matter and digestible nutrient intakes by growing mithun were observed to be increased with the increase of supplementation of dry concentrate feed. Roughage to concentrate ratio did not affect the nutrient digestibility. Mithun calves drank an average of 4.30 litres water for each kg of dry matter intake. Metabolic water was significantly (P<0.01) increased with the increase of supplementation of concentrate feed whereas water turn over, which depends upon the body weight of the animals, did not differ significantly on offering of lower or higher level of dry feed. Faecal water loss of growing mithun was decreased with the increase in intake of concentrate feed and was estimated to be 33～46% of total water intake. Excretion of water through faeces of mithun was about 3.8% of body weight. It could, therefore, be inferred that water intake by mithun varied with seasons, rearing systems and dry feed consumption. As far as the water nutrition is concerned, it is needed to give an attention while feeding mithun in summer with dry feed supplementation under semi-intensive system of rearing.     

广东省罗非鱼主养区无乳链球菌的分离、鉴定与致病性

从广东省5个罗非鱼主养区患暴发性的罗非鱼中分离到15株菌,挑选其中的5株(不同地域、不同组织分离的菌株)进行人工感染试验,表现出自然发病的症状,确定此5株分离菌为导致罗非鱼暴发病的主要病原。通过形态学观察和生理生化实验,并结合16SrRNA基因序列分析,5株分离菌株均为无乳链球菌(Streptococcus agalactiae)。5株分离菌在形态学和生理生化实验结果上保持一致,16SrRNA基因序列同源性达98.6%～99.8%,但在致病性和对药物的敏感性上却呈现一定的差异。另外10株分离菌株通过生理生化实验鉴定也为无乳链球菌。研究表明,广东省罗非鱼流行性暴发病的病原菌主要为无乳链球菌。     

国家西部测图工程产品模式设计与实践——以1:50000影像地形图为例

为实现国家西部1∶50 000地形图空白区测图工程:丰富产品种类,拓展服务领域的设计宗旨,根据ISO 9000对产品的概念,提出了西部测图工程整体产品模式,并对其进行细化,建立了国家两部测图工程地形图产品模式.本文以西部测图工程1∶50 000影像地形图的设计与实现为实例,详细介绍了1∶50 000影像地形图测绘新产品...     

耦合人群移动的COVID-19传染病模型研究进展

构建传染病模型可为疫情防控与公共卫生研究提供至关重要的规划与解析工具。由于宿主行为是传染病传播动态的决定性因素之一,有效耦合人群时空行为对以人为宿主的传染病建模具有重要意义。得益于人群移动大数据研究与应用的快速发展,新型冠状病毒肺炎（COVID-19）的疫情建模研究中呈现出了耦合人群移动建模的显著特征。为系统深入理解该项传染病模型研究中的重要进展,本文对相关文献进行分析与总结。首先,本文分析了COVID-19疫情与人群移动的交互影响,说明了耦合人群移动构建COVID-19模型的必要性。然后,根据建模的目的和原理,从疫情短期预测与过程模拟2个角度,对耦合人群移动的COVID-19传染病模型进行分类梳理。其中,根据耦合人群移动的方式,本文将面向疫情短期预测的模型分为人群移动一阶量与人群移动二阶量的耦合模型,将基于过程模拟的模型分为群体级别和个体级别的耦合模型。最后,本文评述了耦合人群移动的传染病模型研究进展和未来发展方向,认为该领域研究亟需更加深入建模与疾病传播相关的复杂人群时空行为、提升模型的空间解析能力、突破精细化时空传播模拟的计算瓶颈、拓展与前沿人工智能方法的融合,并构建普适而开放的建模数据与工具以促进应用发展。     

软流圈气体压力和洋板自重驱动海底扩张

基于地幔软流圈不断产生高温气体的事实和气体压力随密度和温度而变的特性，提出：洋板（海洋岩石圈部分）随其下高温气体积聚增压而逐渐上隆，最后会从弯张应力最大的中部断裂并弹性回缩；熔岩随气体喷出楔入裂缝，使洋板保持拱隆状并使其下气体压力骤降；洋板因自重下沉并产生巨大推力，使相邻大陆向两旁分离或将洋板边缘推入软流圈而熔融；楔入的熔岩形成新洋板和密闭条件使高能气体又重新积聚，旧洋板向两旁推移。这一过程的往复进行即形成海底扩张和大陆漂移。并认为陆板（大陆岩石圈部分）薄化是使其分裂而开始海底扩张的原因。由概化力学模型进行验算所得的洋脊隆起高度、洋脊隆起形状、洋脊在水平面上的分布规律和海底扩张的运动规律等，都与实际情况相符。     

Water Intake and Utilization in Mithun （Bosfrontalis）： Effect of Environmental Temperature,Rearing System and Concentrate Feed Supplement

Seasonal and sexual variations as well as the effect of dry feed supplement on total drinking water intake and its utilization were observed in mithun （Bosfrontalis） - a semi-wild animal found in North Eastern Hill Region （NEHR） of India. In a completely randomized design, twelve adult mithuns （B. frontalis） as per their sex and body weight were assigned in two different rearing systems （free grazing and free grazing with dry concentrate feed supplementation）, and ten growing male mithuns as per their body weight assigned in two different levels of dry concentrate feed supplementation （1.o kg and 2.0 kg dry concentrate feeds on green forage based diet） and in two different seasons （summer and winter）. It was observed that the environmental temperature had a significant effect on drinking water intake by mithuns. Drinking water consumption （per unit of body weight） was significantly （P 〈 0.05） higher in summer than in winter. Supplementation of concentrate feed on free grazing animals resulted in increase in water consumption. Total water consumption （drinking as well as performed water） was found to be 15.18 litres per 100 kg body weight by growing mithun. Feed dry matter and digestible nutrient intakes by growing mithun were observed to be increased with the increase of supplementation of dry concentrate feed. Roughage to concentrate ratio did not affect the nutrient digestibility. Mithun calves drank an average of 4.30 litres water for each kg of dry matter intake. Metabolic water was significantly （P〈0.01） increased with the increase of supplementation of concentrate feed whereas water turn over, which depends upon the body weight of the animals, did not differ significantly on offering of lower or higher level of dry feed. Faecal water loss of growing mithun was decreased with the increase in intake of concentrate feed and was estimated to be 33 - 46 % of total water intake. Excretion of water through faeces of mithun was about 3.8 % of body weight. It could, there     

胶北地区内生金矿成矿规律

胶北内生金矿是壳幔混源岩浆期后热液成矿 ,受复合基底EW向构造的早新华夏系和郭家岭超单元控制 ,蚀变、矿化分阶段连续进行 ,分为焦家式、灵山式、玲珑式及上庄式四个亚类型。金矿床区域上东西成行、南北成列、汇集成片呈棋盘格局 ;矿带内矿床沿走向等距分布、沿横向对应出现 ,矿床类型横向具分带、走向有变化、倾向相对稳定。矿体在控矿构造引张扩容段和构造叠加段赋存 ,并具斜立、侧伏、尖灭再现、斜列、瓦叠等产出规律。