一种基于版式关联模型的地图整饰方法

围绕专题地图的异质同构特点进行了分析与探讨,针对传统地图整饰方法所存在的问题,提出了一种基于版式关联模型的地图整饰方法。其主要思想是：在地图模板模型的基础上,提炼专题图中辅助要素的共性和个性特征,参考面向对象设计原则,构建一套地理要素和辅助要素二次逻辑关联的地图整饰方法与流程,可以实现专题地图的快速批量制作。实践表明,该方法较传统整饰方法更为重用和高效。     

一种异构多核架构快速查询多边形图层间空间关系的方法

目前,空间关系查询中常用的Plane Sweep 算法是一种串行方法,而关于多核CPU的并行查询算法,在面对海量数据查询时,由于CPU核心数及线程数量的限制,其难以满足查询效率需求。针对该问题,本文提出了一种全新的异构多核架构多边形图层间空间关系查询的并行算法。首先,利用STR 树索引过滤不相交的多边形;然后,对过滤后多边形的线段构建四叉树索引,利用CPU+GPU架构并行计算线段的相交以判断多边形环间的拓扑关系;再根据环间的拓扑关系计算多边形间的维度扩展九交模型(DE-9IM)参数值,据此确定多边形间的空间关系;最后,通过实验验证了该算法的准确性和高效性。实验表明,本算法能有效缩短大数据量的空间查询时间。在实验中逐渐增加目标数据集和源数据集多边形的数量,当两数据集都为50 000 个多边形时,以包含关系为例,相比于ArcGIS,本文提出的算法可达到2 倍的加速比。     

Development of the universal and simplified soil model coupling heat and water transport

It is very important to develop a universal soil model with higher simplicity and more accuracy, which can be widely applied to very general cases such as wet or dry soil, frozen or unfrozen soil and homogeneous or heterogeneous soil. Firstly in this study, based on analysis of both magnitude order and the numerical simulation results, the universal and simplified soil model (USSM) coupling heat and mass transport processes is developed. Secondly, in order to avoid the greater uncertainty caused by the phase change term in numerical iteration process for the model solution obtaining, new version of the universal simplified soil model (NUSSM) is further derived through variables transformation, and accordingly a more efficient numerical scheme for the new version is designed well. The simulation results from the NUSSM agree with the results from more complicated and accurate soil model very well, also reasonably reproduce the observed data under widely real conditions. The new version model, because of its simplicity, will match for the development of land surface model.     

基于异构网络进程实时通信的研究

针对异构计算机网络的互联和网络实时通信这两方面的问题,提出了异构网络的同构化思想,讨论了网络实时通信的实现方法,并给出了异构网中解决进程实时通信问题的模型和方案。     

Numerical Sensitivity Studies on Effects of Ice Nucleating Processes on Electrification in Thunderstorms

This study employed numerical simulations to explore the impact of varying ice nucleation processes on the microphysics and electrification within thunderstorm clouds. A two-dimensional cumulus model, incorporating both non- inductive and inductive charge separation schemes, was utilized. The findings revealed that the freezing nucleation mechanism significantly influenced the microphysical development, electrification, and charge structure of thunderstorms. Homogeneous freezing generated a large quantity of small ice crystals near the cloud tops, which were primarily re- sponsible for the development of positive charge regions through a non-inductive charging process. Conversely, hetero- geneous freezing resulted in larger ice crystals, enhancing graupel formation and leading to a more rapid and intense charge separation rate of around ?15°C. Ice crystals formed heterogeneously and charged negatively during the development stage, resulting in an inverted dipole charge structure. When both immersion and homogeneous freezing processes were considered, the competition between these two distinct freezing processes resulted in reduced cloud water content and weaker electrification. Under conditions of low cloud water content at lower storm levels, graupel particles were negatively charged through non-inductive charging, causing the charge structure to quickly revert to a normal dipole structure.     

Mosaic方法在非均匀下垫面上的适用性研究

在非均匀下垫面情况下, Mosaic方法是目前国际上广泛运用于模式中计算地表通量的方法.大量的研究表明, 下垫面的非均匀分布会引发局地环流, 非均匀分布的空间尺度较大时, 所引起的环流甚至可以达到海陆风的强度.这种环流的存在直接影响到次网格地表通量的计算.次网格地表非均匀分布, 尤其是大尺度模式中的次网格非均匀分布, 必将影响地表通量的计算.本文针对次网格地表非均匀问题, 设计了高分辨率的Mosaic试验和非均匀试验, 开展了不同背景风情况下的一系列数值试验, 以探讨这种影响的程度.结果表明, 在土壤湿度空间分布不均匀的情况下, 运用Mosaic方法计算得到的地表潜热通量偏小, 背景风较小的时候偏差较大, 背景风增强时偏差减小.     

一种基于服务器场的分布式WebGIS计算模型设计与实现

分析传统网络地理信息系统(WebGIS)体系的弊端,从负载均衡与地图状态同步的角度提出一种基于服务器场的分布式WebGIS计算模型。通过自定义服务器场底层交互协议、地图服务器场分布式动态均衡调度算法、地图状态对象池技术,解决了传统WebGIS计算模型异构兼容性差、并行处理能力弱、地图状态对象无法同步等问题,并建立试验床对该模型的性能进行验证。     

Enhancements of Major Aerosol Components Due to Additional HONO Sources in the North China Plain and Implications for Visibility and Haze

The Weather Research and Forecasting/Chemistry model(WRF-Chem) was updated by including photoexcited nitrogen dioxide(NO2) molecules,heterogeneous reactions on aerosol surfaces,and direct emissions of nitrous acid(HONO) in the Carbon-Bond Mechanism Z(CBM-Z).Five simulations were conducted to assess the effects of each new component and the three additional HONO sources on concentrations of major chemical components.We calculated percentage changes of major aerosol components and concentration ratios of gas NO y(NOyg) to NO y and particulate nitrates(NO-3) to NO y due to the three additional HONO sources in the North China Plain in August of 2007.Our results indicate that when the three additional HONO sources are included,WRF-Chem can reasonably reproduce the HONO observations.Heterogeneous reactions on aerosol surfaces are a key contributor to concentrations of HONO,nitrates(NO 3),ammonium(NH + 4),and PM 2.5(concentration of particulate matter of 2.5 μm in the ambient air) across the North China Plain.The three additional HONO sources produced a～5%-20% increase in monthly mean daytime concentration ratios of NO-3 /NO y,a ～15%-52% increase in maximum hourly mean concentration ratios of NO-3 /NO y,and a ～10%-50% increase in monthly mean concentrations of NO-3 and NH+4 across large areas of the North China Plain.For the Bohai Bay,the largest hourly increases of NO-3 exceeded 90%,of NH+4 exceeded 80%,and of PM 2.5 exceeded 40%,due to the three additional HONO sources.This implies that the three additional HONO sources can aggravate regional air pollution,further impair visibility,and enhance the incidence of haze in some industrialized regions with high emissions of NO x and particulate matter under favorable meteorological conditions.     

分布式多源地理信息交换系统体系研究

参照OGC的有关规范标准,对分布式多源地理信息交换系统体系结构模型进行了初步研究,给出了多源地理信息交换系统的工作原理和实现方法。     

西北地区典型下垫面空气动力学阻抗估算方法改进及其验证

利用2010年古浪近地层野外观测试验取得的干旱区典型下垫面（荒滩、沙漠和农田）的观测资料,对常用的3种空气动力学阻抗算法——Verma—R算法、Liu算法、Thom算法进行了适用性检验,并通过分离Thom算法中的动量和热量粗糙度对其进行改进（下称Thom-2算法）。对比不同下垫面空气动力学阻抗估算结果发现：在沙漠和荒滩下垫面,动力因素较热力因素影响大,空气动力学阻抗与风速的指数关系较农田下垫面明显;与其他3种算法相比,考虑了热量粗糙度的Thom-2算法在各种典型下垫面上的估算结果与观测值相比偏差最小,且在较为均匀的荒滩和沙漠下垫面上估算的空气动力学阻抗精度较农田高;通过比较4种算法估算干旱区不同典型下垫面空气动力学阻抗结果,说明干旱区空气动力学阻抗的估算应考虑热力粗糙度的影响。