ON THE RELATION BETWEEN THE EVOLUTION OF NATURAL ENVIRONMENT AND HUMAN FACTORS AND THE DEVELOPMENT OF URBAN SETTLEMENT——Take the Lanzhou Valley Basin as An Examples

Lanzhou Valley Basin is composed of two smaller diamond-shaped basins striking from NW to SE and including 6 river terraces. The lower terraces remaining even and smooth are main sites for city buildings. The main function of Lanzhou urban settlement is a ferry and transport centre. Lanzhou used to be an im-portant crossing site and post on the "silk road",and then became a transport and trade centre in Northwest China. In the middle part of the 17th century, Lanzhou became the capital of Gansu,a new province. The development process of Lanzhou urban settlement indicates that urban settlement is a system consisting of natural environment and human society based on the former.     

一种准中断直接输入的实用高速采集系统

高速采集系统不仅要有高速A/D,而且必须有高速的采集方式。本文提出一种简单易行的高速采集接口电路,并对关键性技术进行分析,最后给出软件流程图和结果。     

Deoxygenation and remineralization above the sediment-water interface; an in situ experimental study

An in situ chamber of volume 3881 and bottom area 0·64 m² was used to determine the flux of oxygen and inorganic nutrients across an estuarine sediment-water interface over a 65-day period. Over the first 7 days, oxygen uptake was 378 mg m^?2 day^?1 and the rates of ammonium and phosphate release were 2·22 and 0·34 mg at. m^?2 day^?1, respectively. The water became anoxic in 14 days.The rates of flux in a similar chamber containing only detritus recently settled from the water column were 371 mg m^?2 day^?1 (oxygen), 1·66 mg at. m^?2 day^?1 (ammonium) and 0 12 mg at. m^?2 day^?1 (phosphate), demonstrating that detritus contributes substantially to exchange across the sediment-water interface.The evolution of the two chambers was similar over the latter part of the experimental period. A third chamber containing only water exhibited very minor changes.The role of detritus in nutrient recycling at the sediment-water interface is discussed in relation to the productivity of shallow water bodies such as the estuary in which the experiment was conducted, which itself undergoes periodic deoxygenation during prolonged stratification. The measured flux of nitrogen across the interface was found to represent approximately 31% of the mean daily phytoplankton requirement.     

城市规划国土管理的图文集成管理

近年来人们已从以往片面追求大而全的ＧＩＳ系统,转向建立能业务化运作的图文办公信息系统。为此,需要研究业务数据和图件资料的集成管理模式,发展基于计算机网络的联网图文查询、检索和操作,设计开发友好的可视化用户界面。本文首先分析总结了城市规划图土管理局日常业务办公所使用和产生的图、文数据,提出了基于局域模式、分量模式、邦联模式的三级图文数据库集成模式和采用ＯＤＢＣ进行异质图文数据库关联的方法,继而根据用     

Two-step interface and velocity inversion—— Study o e of the Tangshan seismic region

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多媒体监控系统软件开发

本文介绍的多媒体监控系统,开发平台为Ｗｉｎｄｏｗｓ９５,采用的程序设计语言为ＶｉｓｕａｌＢａｓｉｃ５．０。它是按照以处理为中心的数据库应用的开发流程进行开发的。该系统结构优化,执行速度快,实现了报警,摄像和录像,云台控制等功能。     

论通信网络的使用者形态：个人对通信媒介的选择

从个人选择通信媒介的理论和概念分析着手,提出了个人媒介选择结构框图,讨论了选择的传统障碍与相对障碍;建立了关于个人选择通信媒介的通用逻辑框模型,分析了媒介特殊效果和评估问题;从石家庄市１０００名通信使用者问卷调查资料为依据,对模型作了概念层次上的检验,指出选择通信个人行为的总体特征是和年龄为最重要因素,受教育水平亦与此有关,性别等并不重要,以及不同地点的选择特性等。     

大口径钻头设计与合理使用专家系统

三口径钻头设计与合理使用专家系统,由大口径钻头设计专家系统、大口径钻头合理使用专家系统、大口径电脑图库三部分组成。详细介绍了该专家系统的知识体系、知识表示以及知识库的维护等内容。     

起伏地形条件下固定点源测深法定量解释研究

采用有限元法对起伏地形下存在不均匀极化体时的多种地电断面进行了固定点源测深的正演数值模拟计算;提出并实现了在起伏地形下利用固定点源测深法资料作相对强度断面图、确定极化体空间位置的方法;通过对不同条件下数值模拟结果的定量解释计算和分析,证明了该方法的有效性;初步总结出了地形对定量解释结果的影响规律。