基于高分辨率数值天气模式的往返平飘式探空轨迹预测方法及初步评估     

王金成  王丹  杨荣康  曹晓钟  郭启云 《大气科学》2021,45(3):651-663

为了开展往返平飘式探空组网观测的仿真和模拟,以及评估组网观测对数值天气预报的影响,并实现往返平飘式探空在目标观测中的应用,本文提出了一种基于高分辨率数值天气模式的往返平飘式探空轨迹模拟和预报方法.基于我国自主研发的GRAPES区域高分辨率模式,初步建立了往返平飘式探空的轨迹预报系统.该系统将往返平飘式探空的上升段、平漂...  相似文献   

天文星表入库的自动化     

高丹  张彦霞  赵永恒 《天文研究与技术》2007,4(1):53-58

天文数据主要包括星表、星图、光谱、文献资料等,其中星表是包含天体信息的数据表格,是天文学家最常用到的天文数据。目前天文数据分布存储在全球各个数据中心。中国最大的天文数据中心是北京天文数据中心,其数据库的重要部分是天文星表数据库。本文阐述了建设天文星表数据库的意义,着重探讨了星表自动入库工具的实现,并介绍了在天文星表数据库基础上的数据融合和数据挖掘。  相似文献   

Effects of afforestation on carbon storage in Boyang Lake Basin, China     

Dan Wu  Quanqin Shao  Jia Li 《中国地理科学(英文版)》2013,23(6):647-654

By using field survey data from the sixth forest inventory of Jiangxi Province in 2003, the biomass and carbon storage for three studied species （Pinus massoniana, Cunninghamia lanceolata, and Pinus elliottii） were estimated in Taihe and Xingguo counties of Boyang Lake Basin, Jiangxi Province, China. The relationship between carbon density and forest age was analyzed by logistic equations. Spatio-temporal dynamics of forest biomass and carbon storage in 1985-2003 were also described. The results show that total stand area of the three forest species was 3.10 × 10^5 ha, total biomass 22.20 Tg, vegetation carbon storage 13.07 Tg C, and average carbon density 42.36 Mg C/ha in the study area in 2003. Carbon storage by forest type in descending order was： P. massoniana, C. lanceolata and P. elliottii. Carbon storage by forest age group in descending order was： middle stand, young stand, near-mature stand and mature stand. Carbon storage by plantation forests was 1.89 times higher than that by natural forests. Carbon density of the three species increased 8.58 Mg C/ha during the study period. The carbon density of Taihe County was higher in the east and west, and lower in the middle. The carbon density of Xingguo County was higher in the northeast and lower in the middle. In general, the carbon density increased with altitude and gradient. Afforestation projects contribute significantly to increasing stand area and carbon storage. Appropriate forest management may improve the carbon sequestration capacity of forest ecosystems.  相似文献   

湖北省近地层风切变特征     

崔杨  陈正洪  何英杰  孟丹 《气象科技》2021,49(5):785-793

为准确掌握湖北省平原湖区近地层风切变特征,利用27座离地高度为120～150m测风塔各1年的逐时测风数据,研究了70～120m间风切变的时空变化特征。结果表明:(1)风切变指数具有明显的季节、日变化特征,普遍在秋冬季最小、夏季较大,夜间大、白天小;(2)位于平原湖区和山区的测风塔在70～120m间的年平均风切变指数分别为0.27和0.12。各塔风切变指数从70m至150m逐渐减小;(3)6座典型测风塔70～120m风切变指数在较稳定状态下的频率最高,为59%～75%;在不稳定条件下的频率最低,均不超过5%;(4)当70m风速在3.0m/s以下、3.0～10.0m/s及10.0m/s以上3个区段时,风切变指数由小变大,在3.0～10.0m/s风速段与年平均风切变指数最接近,10.0m/s以上风切变指数离散性最强;(5)分别推算出实测和数值模拟的风切变指数,中部平原地区实测值明显高于模拟值,总体偏差范围是-0.06～0.14。该结论可用于近地层低风速地区不同高度的风速推算或订正,以提高这类地区风能资源评价、开发规划、风电场选址的科学性以及风电功率预测的准确性。  相似文献   

Development of combined biological technology for treatment of high-strength organic wastewater and results of case studies     

REN Nanqi WANG Aijie HAN Hongjun MA Fang DING Jie SHI Yue ZHAO Dan 《中国海洋大学学报(英文版)》2006,5(4):311-316

Our study group has developed a unique combined ters from the industries of dyestuff, pharmaceutical, chemical biological technology to treat high-strength organic wastewaengineering and zymolysis by using the principles of anaerobic ecological niche and bio-phase separation. The study obtained five national invention patents and eight patent equipments. This technology contains four kernel processes - two-phase anaerobic-aerobic process, hydrolysis-acidification-oxidation process, UASBAF-oxidation process, and internal cycling-hydrolysis-oxidation process. Fifteen pilot projects were accomplished in the basins of Tai Lake, Huai River, Liao River and Songhua River, and their total capital investment reached 185.214 million Yuan （RMB）. Compared to conventional wastewater treatment technology, the innovative technology is more costeffective for high-strength organic wastewater treatment, can save capital investment by 15% - 30%, lessen land usage by 20% to 40% and decrease the operating cost by 10% to 25%. The operating cost of treatment per cubic meter industrial wastewater could be below 0.6 to 1.4 Yuan （RMB）.  相似文献   

基于用户的城市旅游电子地图设计系统的研究与实践   总被引：1，自引：0，他引：1  

李丹 《测绘与空间地理信息》2008,31(2):149-151

随着旅游行业的蓬勃发展,城市旅游地图逐渐成为生命力最为旺盛的专题地图之一,被越来越多的人接受和使用。这里对城市旅游地图的现状进行了深入分析,根据其存在的问题与实际需求提出了基于用户的城市旅游电子地图设计系统,并提供了系统研究内容、系统功能,最后给出了具体实践,证明了系统的可行性与可用性。  相似文献   

数字化城市管理新模式实现中的空间数据建设   总被引：1，自引：0，他引：1  

王丹  李海明  田飞 《地理信息世界》2008,6(4)

空间数据在数字化城市管理新模式实现中不仅起了十分重要的支撑和保障作用,而且大大提升了该模式的应用功效.本文介绍了新模式中空间数据的类型及基本质量要求,分析了专题数据、地理空间框架数据和元数据建设的技术方法、质量控制措施以及存在的问题,提出了相应的对策建议.  相似文献   

Experimental Investigation of the Mechanical Behavior in Unloading Conditions of Sandstone After High-Temperature Treatment   总被引：2，自引：0，他引：2  

Qi-Le Ding  Feng Ju  Xian-Biao Mao  Dan Ma  Bang-Yong Yu  Shuai-Bing Song 《Rock Mechanics and Rock Engineering》2016,49(7):2641-2653

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A QUANTITATIVE-COMPARATIVE APPROACH TO ANALYSIS OF DISTORTION IN MENTAL MAPS     

Stanley Waterman  Dan Gordon 《The Professional geographer》1984,36(3):326-337

A quantitative procedure for analyzing and comparing distortion in mental maps is presented. Using a microcomputer and digitizer, and by developing a distortion index, comparisons are made by direct analysis of mental maps. A case study of the mental maps of Israel of high school and university students showed a tendency to generalize shape to simple geometric forms, with foreshortening of north-south lines and exaggeration of east-west distances.  相似文献   

Seasonally ice free glacial nordic seas without deep water ventilation     

Dan Seidov  Mark Mastin 《地学学报》1996,8(3):245-254

At present the Nordic Seas are a key region of North Atlantic Deep Water (NADW) formation. Two alternative scenarios have been suggested by some authors for the Last Glacial Maximum: (i) the Nordic Seas were permanently covered by sea ice, preventing the formation of NADW, or (ii) that they were seasonally free of ice and that deep water formation did occur. A modified scenario is presented here based on parallel ocean circulation modelling results from the GFDL primitive equation model and a planetary geostrophic model. It is suggested that the glacial Nordic Seas were at least seasonally ice free, but it is observed that there was never deep water formation from the surface; rather it occurred only in the North Atlantic south of 40°–50°N. North of 40°N, the weaker LGM northward flowing thermohaline conveyor is subducted below a reverse conveyor which occurred to a depth of over 1000 m. Various modelling experiments presented here indicate that the reversed conveyor was primarily caused by the colder conditions of the glacial North Atlantic that led to far stronger zonality of glacial analogue of the North Atlantic Current.  相似文献