徐州市土地利用变化的遥感监测

以1987、1994、2003年的卫星遥感图像TM为主要数据源,利用神经网络分类法提取出土地利用类型信息,计算出徐州市各土地利用类型数量、比例以及土地利用类型变化的变化率指数,在此基础上构建起土地利用变化的空间分布图,据此分析了徐州市16年来土地利用时空变化特征.结果表明:建设用地和水体的面积急剧增长致使耕地的面积大幅度减少,煤炭资源的开采是引起耕地塌陷积水以及村庄搬迁的重要原因.     

过去1 300年南海东岛生态环境对气候变化的响应

东岛牛塘为目前在西沙群岛少见的淡水型湖泊,其中保存完好的粪土沉积物记录了距今1 300年来东岛生态环境演化历史.对DY4粪土沉积柱的研究结果表明,在1 400 AD前,东岛海鸟数量较多,牛塘湖岸周围植被生长较为繁盛,而在1 400~1 850 AD期间,东岛海鸟数量和植被生长都处于低谷.通过综合对比研究区、中国乃至北半球降雨量、温度变化记录,发现1 400 AD前岛屿生物量较高的时期对应于暖干的中世纪温暖期,而低生物量时期与凉湿的小冰期一致,证明南海热带孤立岛屿生态系统对区域乃至全球气候环境变化响应非常灵敏.     

^226Ra evidence for the ecosystem shift over the past 40 years in the North Pacific Subtropical Gyre

Surface seawater was collected for ~(226)Ra measurement in the North Pacific Subtropical Gyre from July to October, 1999 and October to December, 2003. Combined with the historical data reported for this sea area, a declined trend of surface ~(226)Ra concentrations was observed since 1960s, indicating the ecosystem shift in response to global warming. On one side, the enhanced stratification of the upper water column resulting from global warming reduced the ~(226)Ra input from the depth, on the other, the temporal increase of biological production resulting from the climate-related ecosystem structure change strengthened the ~(226)Ra removal from the surface ocean. Both the physical and biological processes resulted in the decrease of surface ~(226)Ra concentrations in the North Pacific Subtropical Gyre. The temporal trend of surface ~(226)Ra concentrations was consistent with the trends of chlorophyll a, silicate, phosphate and primary production previously reported. This study provided ~(226)Ra evidence for the ecosystem shift under global change.     

Holocene climatic and environmental changes recorded in Baahar Nuur Lake core in the Ordos Plateau, Inner Mongolia of China

A 5.3 m lake core was drilled in Baahar Nuur Lake in the Ordos Plateau, and measurements of meangrain size, organic δ 13C (δ 13Corg), organic carbon content (TOC), C/N, carbonate content, carbonate δ 13C(δ 13Ccar) and δ 18O (δ 18Ocar) were conducted for retrieving the Holocene chronosequence of climaticchanges based on 15 AMS 14C dates. The record documented four major stages of climate change inthe Ordos Plateau: (IV) a cold and dry condition before ～7.65 14C ka BP; (III) a warm and humid stagebetween ～7.65 and ～5.40 ka BP; (II) a generally drier and cooler climate since ～5.40 ka BP with twohumid events occurring from ～4.70 to ～4.60 ka BP and from ～4.20 to ～3.70 ka BP, and (I) a dry climatecharacterized by complete desiccation of the lake after 3.70 ka BP. Stage III can be further divided intothree sub-stages: (IIIa) a warm and humid episode from ～7.65 to ～6.70 ka BP, (IIIb) a warm and relativelydry episode from ～6.70 to ～6.20 ka BP, and (IIIc) the magthermal and maghumid episode of the Holo-cene from ～6.20 to ～5.40 ka BP.     

Construction of a novel economy-climate model

An attempt has been made to construct a novel economy-climate model by combining climate change research with agricultural economy research to evaluate the influence of global climate change on grain yields. The insertion of a climate change factor into the economic C-D (Cobb-Dauglas) production function model yields a novel evaluation model, which connects the climate change factor to the eco-nomic variation factor, and the performance and reasonableness of the novel evaluation model are also preliminarily simulated and verified.     

Ecosystem vulnerability of China under B2 climate scenario in the 21st century

This paper applies climate change scenarios in China based on the SRES assumptions with the help of RCMs projections by PRECIS （providing regional climates for impacts studies） system introduced to China from.the Hadley Centre for Climate Prediction and Research at a high-resolution （50 kmx50 km） over China. This research focuses on B2 scenario of SRES. A biogeochemical model ＂Atmosphere Vegetation Integrated Model （AVIM2）＂ was applied to simulating ecosystem status in the 21st century. Then vulnerability of ecosystems was assessed based on a set of index of mainly net primary production （NPP） of vegetation. Results show that climate change would affect ecosystem of China severely and there would be a worse trend with the lapse of time. The regions where having vulnerable ecological background would have heavier impacts while some regions with better ecological background would also receive serious impacts. Extreme climate even would bring about worse impact on the ecosystems. Open shrub and desert steppe would be the two most affected types. When the extreme events happen, vulnerable ecosystem would extend to part of defoliate broad-leaved forest, woody grassland and evergreen conifer forest. Climate change would not always be negative. It could be of some benefit to cold region during the near-term. However, in view of mid-term to long-term negative impact on ecosystem vulnerability would be enormously.     

辽东半岛新石器文化经济形态转化与环境变化的关系

辽东半岛的小珠山、后洼文化遗址是新石器时期辽南地区重要的文化遗址.通过对考古文化特征与渔猎—农耕经济的兴衰发展的分析,并结合孢粉、黄土等古气候指标对中国北方地区全新世气候变化进行的研究,同时叠加辽东半岛地区的海岸地质地形条件等特征,探讨了辽东半岛地区古文化与全新世环境演变的关系,揭示了该地区新石器时期以来文化受生产力发展的影响机制.5000 aB.P的寒冷期,人类应对气候突变的响应不同,直接导致小珠文化的兴盛与后洼文化的衰退.     

XML数据交换技术在电子监察系统中的应用

电子监察系统是电子政务系统中的一种，其数据的采集面对多个行政审批系统，情况复杂．文章利用XML技术设计了“数据采集代理机制”，并对其核心部件“XML-RDBMS数据转换”中间件进行了详细的阐述，实现了数据采集的灵活性和一致性，增强了系统的扩展性。     

浅析河曲民歌中的民俗及其流变

文章结合青莱高速公路七合同段台背回填施工工艺及质量控制，并根据实际施工情况提出了一些建议，为以后公路台背回填的施工提供了宝贵经验。     

近50年内蒙古多伦县气候变化特征分析

以1961～2005年多伦县气象站气象记录为主要数据来源,选取气温、降水量、蒸发量、干湿度等指标,采用常规统计分析方法,进行了年均和季度变化的时间序列分析.结果表明:多伦县年均气温趋于上升趋势,降水量波动较大,并且夏季降水量对全年降水量贡献最大.年均蒸发量总趋势是下降的,整体上比较稳定.干湿度趋于上升,呈现变湿润趋势.近50年来多伦县气候呈现增温增湿的趋势.