杭州城区土地利用类型对PM2.5浓度影响分析     

潘骁骏  侯伟  蒋锦刚 《测绘科学》2017,42(10)

针对PM2.5质量浓度空间分布的季节性差异与土地利用分布的定量关系问题,该文以浙江省杭州市为实验区,收集PM2.5质量浓度实测数据和MODIS气溶胶光学厚度(AOT)遥感数据,并对AOT进行标高订正和水汽校正,建立了PM2.5质量浓度和AOT的回归模型,通过模型得出了杭州市各季节的PM2.5质量浓度空间分布图;在此基础上,进一步分析了杭州市PM2.5浓度与土地利用类型(扬尘地表与非扬尘地表)之间的空间分布相关性。结果表明,杭州市2015年PM2.5质量浓度分布的季节性变化特征是冬季春季秋季夏季;建设用地和交通用地等扬尘地表对PM2.5的浓度贡献较大,特别是在冬季和春季两个季节。该研究结果对于认识空气中PM2.5的来源与时空分布特征具有一定的理论和实践意义。  相似文献   

Sensitivity of open-water ice growth and ice concentration evolution in a coupled atmosphere-ocean-sea ice model     

《Dynamics of Atmospheres and Oceans》2017

A coupled atmosphere-ocean-sea ice model is applied to investigate to what degree the area-thickness distribution of new ice formed in open water affects the ice and ocean properties. Two sensitivity experiments are performed which modify the horizontal-to-vertical aspect ratio of open-water ice growth. The resulting changes in the Arctic sea-ice concentration strongly affect the surface albedo, the ocean heat release to the atmosphere, and the sea-ice production. The changes are further amplified through a positive feedback mechanism among the Arctic sea ice, the Atlantic Meridional Overturning Circulation (AMOC), and the surface air temperature in the Arctic, as the Fram Strait sea ice import influences the freshwater budget in the North Atlantic Ocean. Anomalies in sea-ice transport lead to changes in sea surface properties of the North Atlantic and the strength of AMOC. For the Southern Ocean, the most pronounced change is a warming along the Antarctic Circumpolar Current (ACC), owing to the interhemispheric bipolar seasaw linked to AMOC weakening. Another insight of this study lies on the improvement of our climate model. The ocean component FESOM is a newly developed ocean-sea ice model with an unstructured mesh and multi-resolution. We find that the subpolar sea-ice boundary in the Northern Hemisphere can be improved by tuning the process of open-water ice growth, which strongly influences the sea ice concentration in the marginal ice zone, the North Atlantic circulation, salinity and Arctic sea ice volume. Since the distribution of new ice on open water relies on many uncertain parameters and the knowledge of the detailed processes is currently too crude, it is a challenge to implement the processes realistically into models. Based on our sensitivity experiments, we conclude a pronounced uncertainty related to open-water sea ice growth which could significantly affect the climate system sensitivity.  相似文献   

中国500强的行业结构及其区域差异   总被引：4，自引：2，他引：2  

钟业喜  陈琳  黄洁 《地理科学》2017,37(2):190-199

中国500强是中国优秀企业的集中体现,决定了中国未来产业乃至经济的发展方向。基于2009~2014年“中国500强”数据,从企业数量和营业收入角度分别对中国500强的行业结构和区域分布概况进行统计分析,继而探讨中国各省市的行业结构及其空间格局特征。结果表明：① 2009~2014年,制造业的上榜企业数量与营业收入占比均保持下降趋势,但制造业在13类行业中仍占主导,是当前中国国民经济中不可或缺的支柱行业;金融业、建筑业、批发和零售业以及房地产业发展势头强劲,是主导产业的重要组成部分;② 中国500强的地理集中度不断提升,东部地区特别是北京、上海、广东3省市以及香港地区是中国500强企业及其营业收入的主要集聚区域;③ 中国各省市行业结构的空间格局特征表现为：行业结构多元化、简单化与单一化并存,呈阶梯状分布;制造业占主导,但各省市制造业所占份额差距大;服务业趋于向东部省市集中;产业结构效益的区域差异显著。  相似文献   

箱模式的一种应用     

徐静琦 《中国海洋大学学报(自然科学版)》1996,(1)

用简化的箱模式进行区域环境气体污染物日均浓度的模拟计算。实例计算表明，用区域内占优势烟源的有效高度作为箱体高度是合理的。  相似文献   

含高浓度有机物及重金属的废水处理方法研究   总被引：2，自引：0，他引：2  

田由芸  袁璟 《海洋与湖沼》1997,28(5):536-542

采用铁屑综合处理含高浓度有机物及重金属的废水。经处理后的废水，重金属和ＣＯＤ均达到国家排放标准，研究了铁屑用量，作用时间等的最佳值，并对作用机理作了解释。  相似文献   

Stress Analysis of Spatial Non-Concurrent Tubular Joints   总被引：1，自引：0，他引：1  

ChenTieyun  Wu Zhengqi Professor  Shanghai Jiaotong University  Shanghai P. h. Doctor  Shanghai Jiaotong University  Shanghai 《中国海洋工程》1994,(4)

The formulations of analytic-numerical method for the stress analysis of non-concurrent spatial tubular joints are introduced in the paper. The spatial DT joints with different eccentricity in the vertical diametrical plane of chord are computed. Finally the influence of eccentricity on the stress at possible hot spots is discussed.  相似文献   

The effects of acid sulphate run-off on a subtidal estuarine macrobenthic community in the Richmond River, NSW, Australia   总被引：1，自引：0，他引：1  

Corfield  Jamie 《ICES Journal of Marine Science》2000,57(5):1517-1523

  相似文献   

Some parameters in arctic sea ice dynamics from an expedition in the summer of 2003     

LI Zhijun  ZHANG Zhanhai  LU Peng  DONG Xilu  CHENG Bin  CHEN Zhi 《海洋学报(英文版)》2005,24(6):54-61

1Introduction Seaiceoccupiesthemainpartofthesurfaceof theArcticOcean.ThefocusoftheSecondChineseNa- tionalArcticResearchExpedition(CHINAE-2003) wastounderstandthevariationsofarcticmarineenvi- ronmentsandtheseaiceeffectsontheclimatechanges ofglobalextent,inmiddleandlowerlatitudesareas, especiallyinChina.Therefore,thejointsea-ice-airob- servationforseaicestudieswasoneofthekeypro- jectsinCHINARE-2003.Theinvestigatedareacov- ered3000kmfromsouthtonorthand900kmfrom westtoeast.Seventemporali…  相似文献   

Concentration level of dissolved cadmium and its variation in surface seawater of Urasoko Bay,Ishigaki Island     

Kazuo Abe 《Journal of Oceanography》2007,63(2):341-347

From April 2005 to March 2006, the concentration of dissolved cadmium (Cd) was monitored in the surface seawater of Urasoko Bay, which is in a subtropical area of the North Pacific Ocean and is surrounded by a well-developed fringing reef. During this period, the observed salinity and Cd concentrations varied in a range of approximately 16–34.5 and 4.8–77.8 pM, respectively. The concentration range of Cd obtained in this study was considered to be too low to damage the coral species, and its variation throughout the year did not show any seasonality and was not connected with climate data. The Cd-salinity plot for all the data in the salinity range over 26 showed apparent non-conservative behavior, which suggests a possible irregular input of Cd from a solid phase through streams and groundwater, release from bottom sediments, and atmospheric deposition into the bay.  相似文献   

基于减小叶片水分影响的湿地芦苇氮浓度高光谱反演研究     

王莉雯  卫亚星 《地理科学》2016,36(1):135-141

以盘锦双台河口湿地国家级自然保护区作为研究区,采用基于bootstrap的偏最小二乘回归模型（PLSR）,分别构建不同光谱变换技术（包括光谱水分影响减小技术WR、包络线去除CR、光谱一阶微分FD、光谱倒数的对数LR）和原光谱数据（R）的芦苇叶片氮浓度预测模型。使用变量投影重要性指标VIP,计算了各光谱波段在估算芦苇叶片氮浓度时的重要性。研究结果表明,WR光谱变换技术的芦苇叶片氮浓度估算精度最高（R²=0.87,均方根误差=0.57）,该方法可以有效减小叶片水分的影响,增强鲜叶片光谱中细微的氮吸收特征。  相似文献