基于AutoCAD的管线调查系统的建设

现有管线调查常用的记录方式有直接用笔记录于调查表格中和使用PDA作为管线外业调查的手簿两种方式,这两种方式都需要大量的内业数据处理。为提高管线调查的效率,进行了基于AutoCAD的管线调查系统的建设。本文介绍了该系统的开发方式,系统功能,作业流程等。着重介绍了管线调查信息的存储、管线信息调查、自动生成调查井位、自动生成高程表和调查表等功能以及操作命令的制作等关键技术。该系统已进行了试点应用,实践证明大大提高了作业效率,取得了良好的效果。     

Objective prism survey of qsos in the field centered at 10h40m + 00°00′

QSO objective prism survey was done for the field centered at 10^h40^m + 00°00. For the 348 objects selected, we present in this paper their positions,B _J magnitudes, spectra, and finding charts. Based on the sample containing 163 QSO candidates with higher reliabilities (F 3), the surface density of QSO candidates withB _J 20 is estimated to be about 4.5 per square degree.Work based on UKST plates.     

钾霞石制备体系碱性滤液的利用技术

为处理钾长石水热制备钾霞石所产生的碱性滤液,本文采用水热法,考察了氢氧化铝溶解时间、晶化时间、晶化温度、水碱比对钾霞石产率和白度的影响,并对合成钾霞石物相进行了表征。结果表明,合成钾霞石的最佳条件为,氢氧化铝溶解时间为1.5 h,晶化时间为4 h,晶化温度280℃,水碱比为1.8。XRD结果表明,产物为钾霞石粉体。傅里叶变换红外光谱表明,Al(OH)₃中的Al在水热条件下进入到Si—O骨架中形成了Si—O—Al官能团,从而印证了钾霞石的合成。差热分析结果表明,合成钾霞石具有良好的热稳定性。氮气吸附结果表明,合成钾霞石比表面积为5.18 m²/g,平均孔径为32.98 nm。实现了钾长石水热制备钾霞石所剩碱性滤液的资源化利用,并为钾长石水热制备钾霞石提供了一种母液循环的思路,使水热制备钾霞石工业化成为一种可能。     

随钻测录井地质导向二维分解实时绘图方法

根据随钻测录井实时地质导向和大斜度、水平井评价成图技术需求，针对传统绘图方法存在的弊端，提出了将测录井信息、井眼轨迹和地质模型进行二维分解的实时绘图方法。针对二维分解绘图方法绘图时空复杂度较高的问题，给出了不同事件驱动下的局部实时计算和拷屏重绘算法，控制了对CPU和内存的消耗、提高了绘图效率，消除了实时绘图的闪烁和卡顿现象。应用实例表明，二维分解实时绘图方法能够实现大尺度随钻测录井地质导向图形的流畅、无卡顿实时绘图，可提高大斜度、水平井储层模型评价的刻画精度和时效。     

人工触发闪电电流测量及特征性分析

通过对１９９３年７月２７日的人工触发闪电电流、跨步电压的直接测量结果的分析发现,在正电场下触发的慢型放电过程由连续电流和双极性的电流脉冲过程组成,其放电特性与雷暴的电特性有关。闪电电流最大值为１．２ｋＡ,持续时间为２５ｍｓ,中和电荷量为８．９Ｃ。跨步电压与电流的测量结果相一致,是一种间接测量电流的方法。     

Food Deserts in the Prairies? Supermarket Accessibility and Neighborhood Need in Edmonton,Canada*

The U.S. and U.K. literatures have discussed “food deserts,” reflecting populated, typically urban, low‐income areas with limited access to full‐service supermarkets. Less is known about supermarket accessibility within Canadian cities. This article uses the minimum distance and coverage methods to determine supermarket accessibility within the city of Edmonton, Canada, with a focus on high‐need and inner‐city neighborhoods. The results show that for 1999 both of these areas generally had higher accessibility than the remainder of the city, but six high‐need neighborhoods had poor supermarket accessibility. We conclude by examining potential reasons for differences in supermarket accessibility between Canadian, U.S., and U.K. cities.     

Ammonium regeneration in intertidal sediments of the Yangtze estuary during air-exposure

The influences of exposure to the atmosphere on ammonium cycle in the intertidal surface sediments were in situ studied with a geochemical approach at a typical station in the Yangtze Estuary during three tidal cycles in September 2003. During an about 8-h emersion period of each diurnal tide, six high-resolution vertical profiles of adsorbed and dissolved ammonium were measured. It was observed that both adsorbed and dissolved ammonium generally had an increasing trend in sediment cores during the exposure. The rate of ammonium regeneration in sediments was estimated using the accumulation amount of ammonium including adsorbed and soluble fractions during the daytime emersion. The calculation result showed that there was relatively high ammonification rate (˜500 nmol N cm⁻³ day⁻¹), which reflected that organic nitrogen in sediments was quickly decomposed with a residence time of ˜52.7 days. Due to the dramatic temperature difference observed in sediment profiles, free convection was considered an important mechanism of regulating the efflux of produced ammonium into overlying waters. The total estimated amount of regenerated ammonium was ˜1.35×10⁵ t N year⁻¹ in the intertidal flat of the Yangtze Estuary, which occupied 7.6% of the total inorganic nitrogen annually transported to the estuarine ecosystem.     

中国岩溶洞穴数据库建设研究

为了有效地保护和利用洞穴这一具有多方面价值的、不可再生的国土资源而建立了中 国岩溶洞穴数据库,首期完成900个洞穴数据建库工作。数据库中含有图、文、声、 像等方面的数字化信息,数据容量2500MB,作为非商业数据,可通过授权共享,为 科研机构、旅游行业和公众提供服务。     

土地变更调查中移动电子地图的建立

本文介绍了基于GPS-PDA的移动电子地图在土地变更调查中的应用与研究。主要讲述了在Windows CE嵌入式操作系统下的电子地图的数据建模，地图功能的实现和相关算法。最后结合实例验证了该软件的合理性和可操作性。     

法国国家测绘局（IGN）述评

法国是世界测绘强国之一。法国国家测绘局（IGN）是法国测绘的领导机构。本文介绍了IGN的概况，并对IGN大地测量、地图制图、对外服务、研究机构等情况作了较详细的描述。在此基础上对IGN的未来发展特点提出了几点看法。