Evaluation and Customization of Different Open Source Desktop GIS Software

This paper gave a general evaluation on existing three popular free and open source desktop GIS projects,according to the selected evaluation criteria.To further the understanding of the open source software,this paper also presented a customization example of QGIS with python and PyQT.     

GIS互操作与OGC规范

不同GIS间的互操作是地理信息共享与服务的一个至关重要的问题,制订地理信息的互操作标准、规范已成为解决问题的关键。本文描述了在分布式计算环境下GIS互操作的含义、面临的问题与标准化需求;简述了开放地理信息系统协会(OGC)的地理信息互操作视点、互操作应用程序接口;着重介绍了互操作规范及其相互关系,已获采纳的实现规范及其制定流程、已进入讨论稿和推荐稿阶段的实现规范。     

利用Access开发岩土工程勘察管理数据库

用Access设计岩土工程勘察管理数据库 ,能对岩土工程勘察各个环节实行全面的、信息化的管理。对各环节的管理信息实现录入、查询、修改、打印数据和表格的功能 ;实现管理图件 (图片 )、声音、影像等多媒体功能 ;实现信息动态发布的网络化功能。岩土工程勘察管理数据库的开发利用简化了工作过程 ,规范了作业行为 ,提高了工作效率 ,推动了信息化、网络化建设 ,具有重要的实用价值     

A LINEAR THEORY FOR DISTURBANCE OF COHERENT STRUCTURE AND MECHANISM OF SAND WAVES IN OPEN-CHANNEL FLOW

1 INTRODUCTIONT'he early theory for tUrbulent boundare layer assumed that the now adjacent to the wall is a lndnar innature and is named lndnar bottom layer Its thickness is about V/u*, Where V is the ldnehc viscosityand u* is the fuchon velocity. Towmsend (l956) first suggested the concePt of tUrbulent strUctUre andpointod out that there are isotroPic small scale nuctUation and quasi-periodic large scale strUcture in theshear flow Einstein and Li (l956) discovered by the flow moving…     

VELOCITY PROFILES OF TURBULENT OPEN CHANNEL FLOWS

1 INTRODUCTIONThe vertical velocity profile of open channel flows is the most basic infOrmation for the stUdy of flowresistance, channel bed stability, river nuvial process and sediment transport. Although it has been asubject of great interest for many years, there does not exist a consensus on some perPlexing questions,such as the position of the theoretical bed level. In order to investigate the properties of velocity profile,data measured in open channel nows from eight sources were …     

浙江拔茅破火山岩浆作用：开放体系多机制复合演化

拔茅火山杂岩的成分变化范围广泛，包括玄武质，玄武粗安质，粗面安山质，粗面英安质，流纹英安质到流纹质和高硅流纹质岩石都有，它们不是由单一母岩浆演化而来，也不是由单一岩浆房喷发形成的，而是来自多种类型的岩浆房，并经历过复杂的演化过程，为开放体系多机制复合演化，其中早期双峰式基性端元是由上地幔部分熔融形成的，而酸性端无则是地壳物质边熔融边喷发（分离熔融）的结果，作为火山杂岩主体的粗面英安质岩石，其岩浆是在高位主岩浆房内由玄武质岩浆与流纹英安质岩浆混合形成的，发生混合的流纹英安质与玄武质岩浆的比例为57：43，而粗面安山质岩浆则是溶部岩浆房内由玄武质岩浆分离结晶形成的，晚期侵出－侵入的流纹英安质岩穹和高硅流纹斑岩株则分别代表高位次级岩浆房的成分及其硅质帽。     

Test of scale modelling of sediment transport in steady unidirectional flow

In two steady uniform flows at different physical scales in a small open channel, with variables characterizing flow, sediment, and fluid adjusted for dynamic similitude by means of four dimensionless modelling parameters (a Reynolds number, a Froude number, a density ratio, and a length ratio), measured frequency distributions of height, spacing, and migration rate of current ripples were almost identical when scaled, thus verifying that exact Reynolds-Froude modelling of loose-sediment transport is valid and workable. Modelling should be valid as well for a wide range of other transport conditions in the same kind of flow, because no additional kinds of forces or effects would be present in transport of loose grains in modes other than as ripples. In scaled-down modelling, a scale ratio of 2.5 is attainable without recourse to exotic fluids by use of water at 85°C to model natural flows at 10°C.     

空间及多媒体数据的数据库存取

如何实现图形数据与属性数据的一体化存储是目前的研究热点。本文以MS Access关系数据库为例，说明空间及多媒体数据实现全关系型存储的理论。从而能克服传统的混合结构模型中空间数据库和属性数据库的繁琐联结的弱点。     

工程MASS软件客户端数据库编辑管理功能的实现

为了对数字地震台网产出数据进行有效地管理，辽宁数字遥测地震台网研制了地震数据管理与服务系统(MASS系统)，MASS系统客户端工程MASS软件实现了对数据库的编辑管理功能，本文对其进行了论述。     

Cross dating (Th/U-C) of calcite covering prehistoric paintings in Borneo

We present the first application of cross-dating (Th/U measured by thermo-ionization mass spectrometry (TIMS) and ¹⁴C measured by accelerator mass spectrometry (AMS)) of calcite covering prehistoric paintings. Th/U age estimates of cave drapery range from 9800 to 27,300 yr B.P. while conventional ¹⁴C age is estimated between 9900 and 7610 yr B.P. depending on the dead carbon correction. The age discrepancy is attributed to a disturbance of Th/U and/or ¹⁴C geochemical systems, showing the limits of the geochronological approach applied to this kind of material. For the Th/U system, the poor consistency of U data (U content, ²³⁴U/²³⁸U activity ratios) and apparent ages argue for open system conditions. For ¹⁴C system, variation of the dead carbon fraction (dcf) and a possible mixing of successive generations of calcite could account for age discrepancy. Nevertheless, one sample shows concordant ages for the two methods. Compatible ages through corrections for open system conditions are assumed for other samples. Then, the cross-dating suggests 9900 yr as the minimum age of the piece of drapery; the underlying painting must be older. This study of rock art demonstrates the presence of a Pleistocene population before 9900 yr in the southeast of Borneo, whereas previously the only population in evidence in this area was of Austronesian type from ∼5000 to 6000 yrs ago.