Case studies of sprite-producing and non-sprite-producing summer thunderstorms

Three summer thunderstorms in the eastern region of China were analyzed in detail using multiple data, including Doppler radar, lightning location network, TRMM （Tropical Rainfall Measuring Mission）, MT- SAT （Multi-Function Transport Satellite） images, NCEP （National Centers for Environmental Prediction） Reanalysis, and radiosonde. Two of the three storms were sprite-producing and the other was non-sprite- producing. The two sprite-producing storms occurred on 1 2 August and 2~28 July 2007, producing 16 and one sprite, respectively. The non-sprite-producing storm occurred on 29-30 July 2007. The major ob- jective of the study was to try to find possible differences between sprite-producing and non-sprite producing storms using the multiple datasets. The results showed that the convection in the 1-2 August storm was the strongest compared with the other storms, and it produced the largest number of sprites. Precipitation ice, cloud ice and cloud water content in the convective regions in the 1-2 August storm were larger than in the other two storms, but the opposite was true in the weak convective regions. The storm microphysical prop- erties along lines through parent CG （cloud-to-ground lightning） locations showed no special characteristics related to sprites. The flash rate evolution in the 1-2 August storm provided additional confirmation that major sprite activity coincides with a rapid decrease in the negative CG flash rate. However, the evolution curve of the CG flash rate was erratic in the sprite-producing storm on 27-28 July, which was significantly different from that in the 1 2 August storm. The average positive CG peak current in sprite-producing storms was larger than that in the non-sprite-producing one.     

航空和高铁对中国城市创新能力的影响

交通运输是创新网络中人才流、资本流等知识与技术流动的物理空间承载,其对城市的创新能力影响已成为经济地理学的交叉前沿热点。论文基于2007—2018年中国城市尺度数据,以航空和高铁运输为例,构建交通运输对城市创新能力影响效应的理论框架,采用双向固定效应面板回归模型,实证检验航空和高铁对城市创新能力的多重异质性机制,并探讨了知识传播、资本积累、产业升级在交通运输与创新能力之间的中介效应。研究发现：① 航空和高铁建设均对城市创新能力有显著正向影响,高铁对城市的创新溢出效应约为航空的3倍。② 航空和高铁对不同类型城市的创新溢出效应存在显著异质性。城市等级异质性方面,航空和高铁对中心城市创新能力的正向影响强度高于非中心城市。人口规模异质性方面,航空对大、中城市创新能力提升有显著正向影响,对小城市有抑制作用;高铁运输则对不同人口规模城市的创新能力均有正向影响,呈现大城市>中等城市>小城市的态势。区域异质性方面,航空和高铁对东、中、西、东北地区的创新能力均有不同程度的提升作用,表现出显著的“马太效应”,东部地区优势地位凸显。③ 航空和高铁均可通过促进技术转移、风险资本配置、外商资本配置间接促使城市创新能力提升。此外,航空还能够通过促进产业升级间接促使城市创新能力提升。     

RELATION BETWEEN THE MRT BUILDING AND UNDERGROUND SPACE EXPLOITATION ——A Case in Guangzhou City

On the basis of analyzing the history and characteristics of the underground space exploitation and theurban space development in Guangzhou, and making a thorough study on the underground space exploitation based on the subway building, this paper points out some main problems in the exploitation of underground space in Guangzhou, and emphasizes that Guangzhou must develop the underground space on a large scale with the aid of the subway building, and puts forward a proposal on the urban space coordinate development between on-ground and underground in Guangzhou City.     

海上吉普赛人

在我国历史上，沿海港湾和内河上有一个特殊的群体，他们从事渔业及水上运输，并且以船为家，他们被称为蛋民，是中国古代最伟大的航海家。一些人类学家认为他们是古越族的后代。20世纪50年代，经过专项调查，“蛋族”被识别为汉族。《蛋民调查》上报国家民委后，经国务院研究确定，蛋人、蛋民、蛋族已是历史名词，今后永远不准使用带有歧视-陛的称号，应称他们为“水上居民”。政府为改善水上居民的生活条件，专门为他们在陆上建起了新村，帮助他们在岸上定居，与当地居民和睦相处。现在，水上居民有了大学生、专家学者、医师、政府领导和企业家以及其他在社会上有名望的人士。     

基于熵的瓶颈运输问题的动态规划解

建立了关于时间（路程）的瓶颈运输问题的动态规划模型，并利用熵作为工具．解决了物品运输过程中所用时间长短的界问题，进而给出易于处理的瓶颈运输问题的动态规划模型。最后给出一个实例说明该方法的实用性和有效性。     

Areas of the global major river plumes

River plumes are the regions where the most intense river-sea-land interaction occurs, and they are characterized by complex material transport and biogeochemical processes. However, due to their highly dynamic nature, global river plume areas have not yet been determined for use in synthetic studies of global oceanography. Based on global climatological monthly averaged salinity data from the NOAA World Ocean Atlas 2009 (WOA09), and monthly averaged salinity contour maps of the East and South China Seas from the Chinese Marine Atlas, we extract the monthly plume areas of major global rivers using a geographic information system (GIS) technique. Only areas with salinities that are three salinity units lower than the average salinity in each ocean are counted. This conservative estimate shows that the minimum and maximum monthly values of the total plume area of the world’s 19 largest rivers are 1.72 × 10 6 km 2 in May and 5.38 × 10 6 km 2 in August. The annual mean area of these river plumes (3.72 × 10 6 km 2 ) takes up approximately 14.2% of the total continental shelves area worldwide (26.15 × 10 6 km 2 ). This paper also presents river plume areas for different oceans and latitude zones, and analyzes seasonal variations of the plume areas and their relationships with river discharge. These statistics describing the major global river plume areas can now provide the basic data for the various flux calculations in the marginal seas, and therefore will be of useful for many oceanographic studies.     

我国最大规模LNG工厂在湖北投运

正中石油集团日前宣布,我国目前规模最大的液化天然气(LNG)工厂——湖北黄冈LNG工厂实现满负荷运行,标志着我国首座国产化百万吨级LNG工厂全面投入运行,打破了国外大型LNG技术与装备长期垄断的局面。据悉,湖北黄冈LNG工厂项目于2012年5月18日动工,     

博爱县大力推进北山治理春季集中整治工作

正5月9日下午,博爱县召开北山治理春季集中整治工作推进会,通报北山治理春季集中行动进展情况,安排下一步的整治工作。4月22日博爱县北山治理春季集中整治部署会议召开后,各乡镇采取不同的方式对反弹的采矿点、矿产品收购点进行取缔,巩固该县"两取缔"成果,取得了一定的成绩。此次行动重新组建了两个由国土资源、