数字环境下的地图传输

根据数字编码与处理特征，对地图传输理论进行了重新分析，建立了数字地图传输模型．     

心象地图在制图传输中的作用

制图传输是制图学的重要研究领域。本文从认知制图的角度,探讨了心象地图在制图传输中的作用;着重分析了心象地图和地图之间的内在联系,指出了人的认知制图能力的客观存在是制图传输得以进行的真正原因;在此基础上,提出了制图传输的扩展模式,增加了从读图者到次读图者之间的传输过程,并从内容和形式等方面分析了它的特殊性,以期完善制图传输模式。     

Growth Of The Summer Daytime Convective Boundary Layer At Anand

The heights of the daytime convective boundary layer (CBL), computed by a one-dimensional model for a bare soil surface at a semi-arid station,Anand, during the dry and hot summer month of May 1997, are presented. As input, the model requires surface heat flux, friction velocity and air temperature as functions of time. Temperature data at the one-metre level from a tower and sonic anemometer data at 9.5 m collected during the period 13–17 May 1997 in the Land Surface Processes Experiment (LASPEX-97) are used to compute hourly values of surface heat flux, friction velocity and Obukhov length following the operational method suggested by Holtslag and Van Ulden [J. Climate Appl. Meteorol. 22,517–529 (1983)]. The model has been tested with different values for the potential temperature gradient ( ) above the inversion. The model-estimated CBL heights comparefavourably with observed heights obtained from radiosonde ascents.     

HD-STGPS超站仪数据通信的实现

介绍了HD－STGPS超站仪的数据电台和GSM两种数据通信的设计，讨论了GPS数据通信的协议和程序实现方法。     

IP网络技术的现状及其多媒体应用研究

介绍了IP网络的现状、实现方式以及发展趋势，并分析了基于IP网络的多媒体通信若干技术和应用。     

支持ITU-T H.324协议的桌面式可视电话系统

介绍了支持ITU－TH．324协议的桌面式可视电话系统VP324的系统原理、总体构成及各个子系统的实现方法，论述了VP324系统中一系列难点的实现策略和主要性能指标。该系统视频清晰流畅，传输帧率最高可达25帧／s，单路时延不超过350ms，在有效带宽仅12k时仍然能够正常工作。     

利用VSAT网络实现GPS差分数据传输

主要讨论了GPS差分基准站与数据中心之间差分信息的传输。介绍了GPS差分网络系统的组成和VSAT卫星通信情况与优势，利用网络技术，以VSAT系统为实例研究了基准站与数据中心之间的实时信息传输，同时通过软件开发完成了数据中心利用VSAT网络对差分基准站的监控。     

MAPINFO下城市地下管网空间分析功能的实现

主要对在MAPINFO平台上如何实现管网空间位置分析、拓扑分析、缓冲区分析以及最短路径及事故分析等空间分析功能的实现思路和算法进行较详细的研究，并用实际探测的管线数据进行功能模拟，模拟后得到了较好的效果。     

中国数字化地震观测系统

介绍了中国地震局“九五”重点项目中国数字化地震观测系统，特别重点介绍了中国数字化地震台网、国家标准数字化地震台、中国地震局卫星数据通信网、中国数字地震台网中心的建设规模、设计思路、技术参数、设备结构、服务功能，以及中国数字地震台网的运行流程和运行状况。     

Antagonistic structures in border areas: Local milieux and local politics in the Polish-German twin city Gubin/Guben

Cross-border communication and co-operation at the Eastern fringe of the European Union seems so far to have been a matter of political initiative and a lot of good will at the levels of national, regional and local governance. This article maintains that everyday culture must be given more notice when cross-border activities are regarded at the local level, especially in twin cities. The case of the German-Polish twin city Guben/Gubin reveals a strong tendency towards a new divergence of thought and action between formal and informal levels of action, namely the level of local politics and governance and the level of local everyday milieux. While the politics of Euroregions, local administrations and local governments is very often directed towards establishing symbolic gestures of border-crossing and mutual understanding, social milieux at the ‘base’ of local societies are rather driven by a paradoxical mixture of hope, anxiety, resentments and prejudice, thus producing contradictions and even conflict with official political initiative. This revised version was published online in July 2006 with corrections to the Cover Date.