微机在r能谱中的应用

本工作用计算机对ｒ能谱获取的数据进行了光滑处理，并通过已知核素在ｒ能谱中的实测数据，拟合出能量道述表达式，选取了适宜的数学模型，对非线性的能量效率曲线进行拟合，提高了定性定量分析的精度和解谱速度，在实际应用中获得了满意的效果。随着核物技术的发展，ｒ能谱在海洋湖沼、环境科学等领域的应用越来越广泛。高分辩率探测器的部世和应用，把该项技术推上更高的水平，一次测量可获得大量校数据，并可同时定性定量分析多种放射性核素，由于射线能量与探测效率的变化是非线性的，而又不遵循一种变化规律，加之背景值的干扰，给ｒ能谱的分析造成一定的困难。计算机的应用为ｒ能谱处理提供了很大方便。     

COMPUTERIZED NAVIGATION ASSISTANCE FOR DRIVERS

Computer-assisted navigation systems provide navigation information to automobile drivers and are now available. They are capable of storing, processing and displaying information about street networks. The display typically mimics a printed street map. The underlying capabilities of these systems present unique opportunities for geographers to study spatial cognition, wayfinding, spatial search, the impact of spatial information on trip behavior, and market responses to potentially different travel patterns. Such systems are reviewed and key areas for future research are identified.     

“Software,Jobs Go Begging,Threatening Technology Boom”: Computer Services Employment in U.S. Metropolitan Areas, 1982 and 1993

The campaign to promote the networking of America underscores the importance of information infrastructures that can support regional competitiveness. One crucial element of a regional information infrastructure is a computer services (CS) industry that supports computer systems, provides backward and forward linkages among all sectors of the economy, serves as engines for economic growth, enhances production efficiency, and encourages innovation. But research on metropolitan CS has been limited, and where CS are analyzed directly, spatial units of analysis vary and CS are rarely disaggregated. This paper situates CS employment within spatial analyses of producer services, outlines infrastructural characteristics, analyzes CS distribution across metropolitan areas in 1982 and 1993, and considers the implications of the findings. The data suggest that while large metropolitan areas are most likely to have a diverse base of specializations in multiple CS types, many smaller metropolitan areas possess CS specializations. We conclude that ranking in the urban CS hierarchy is more likely to be a function of local economic structure than metropolitan population. The uneven dispersion of CS capacity across metropolitan areas potentially has negative ramifications for implementation of national policy and development of underserved regional economies.     

中国大渤海圈沿岸港口外向型经济腹地的划分模拟

本文利用地理信息系统网络分析的方法和技术,对大渤海圈沿岸港口外向型经济腹地的划分,进行了计算机模拟研究,给出了不同划分原则下的模拟结果,显示出计算机模拟研究方法的效能和灵活性。     

CYBERSPACE AND VIRTUAL PLACES

ABSTRACT. Computer networks are often described in terms that imply a virtual space or place: electronic frontier, cyberspace, and information superhighway have been used to indicate computer networks as a whole; cafés, dungeons, and virtual offices are some of the “places” people refer to as being in or on networks. The use of this language, which I collectively call “virtual-place metaphors,” indicates three broad metaphorical themes: virtual architecture, electronic frontier, and cyberspace. The metaphors encourage control, surveillance, and capitalist expansion through computer technologies—and also evasion and resistance through computer technologies.     

地貌形态模拟

对地貌模拟,常用的物理机制和统计规律都有其自身的水足之处。而采用地貌形态模拟的方法,即运用地理地再现地貌形态的空间特征和地貌演化的过程。这一技术的实现在于创建四维地貌数据库,建立分形地貌模拟模型,用分形内插技术实现地貌形态的模拟。四维地貌数据库扩充了数字地面模型数据库,分形地貌模拟模型第一次反地貌的分形特征用计算机模拟实现。同其它地貌模拟方法相比,本模型具有定量化、快速准确、操作方便和视觉效果好等     

Volume 111 Index

Abstract

Concepts related to alternative map projections can be difficult to explain to students given the diversity and complexity of available projections. Students frequently have trouble understanding how distortions caused by the choice of a projection can affect map readability and comprehension. Programs available for personal computers now provide geography and cartography instructors with a method for interactively educating students concerning the distortions associated with alternative map projections. Such software can be incorporated into laboratory assignments in introductory geography courses or in more advanced courses that deal with map design or thematic cartography.     

定量遥感尺度效应刍议

目前定量遥感在面向国家需求、面向基础研究方面,存在海量遥感数据无法有效利用、定量遥感研究缺乏普适性和系统性、遥感应用难以再上新台阶等主要问题。因此,目前的遥感科学研究需要整合,需要向前迈出一大步。由于地表的异质性,我们如果只停留在演绎普适的机理模型在特定地点作个性化的处理,是不能适合地学的应用和研究的。必须在已有的反演和实验数据的基础上,用归纳的方法,总结出一些规律性的东西。走我国自然地理学"自上而下的演绎方法和自下而上归纳方法的结合"研究"尺度综合"的路子,在解决遥感科学核心问题"尺度效应"方面先搭建一个方法框架,同时建立几个开放的相关平台(如数据,反演,计算机模拟,等等),与有关学科的专家共享。     

The use of digital image analysis in the study of laminated sediments

The use of digital image analysis for the investigation of many natural phenomena is not novel. A vast amount of literature exists on its application to the study of a diversity of physical characteristics from many environments. The power of this tool is now being realised, however, in the study of sediments, from both marine and lacustrine environments. The advent of image processing applications for use in a personal computing environment, and the availability of high resolution digital video cameras, are serving to bring the technique to the desktops of many researchers. This paper will attempt to review those techniques which may be found useful by researchers contemplating the use of image analysis in this type of study, and in particular those who need to count laminations in order to construct a chronology, or to compile time series from lamina thickness or composition, for comparison with those derived from other datasets. Much of the information may be found already in print, but it derives from many disciplines, and does not seem to have been documented previously in this connection.     

A Note On Spatial Autocorrelation

BITNET is a telecommunications network for higher education. The network's general characteristics, services, the availability of BITNET to academic geographers, and their use of the system are examined. Although more than 80% of geography faculty in the United States and Canada are at BITNET-supported institutions, a survey of AAG Specialty Group chairs suggests that geographers' actual use of BITNET is relatively low.     

BITNET: A TOOL FOR COMMUNICATIONS AMONG GEOGRAPHERS*

BITNET is a telecommunications network for higher education. The network's general characteristics, services, the availability of BITNET to academic geographers, and their use of the system are examined. Although more than 80% of geography faculty in the United States and Canada are at BITNET-supported institutions, a survey of AAG Specialty Group chairs suggests that geographers' actual use of BITNET is relatively low.     

The Role of the Geography Teacher in Democracy Fulfillment

Abstract

Economic Restructuring and Political Response by Robert A. Beauregard, ed. Newbury Park, 1989. 245 pp. ISBN 0-8039-3184-0. $16.95, paper.

Exploring Your World: The Adventure of Geography The Special Publications Division, The National Geographic Society, 1989.

The Incredible Adventures of Daniel Boone's Kid Brother, Squire by Fred Conway New Albany, IN: FBH Publishers. 1992. 110 pp. ISBN 0-9925165-08-5. $9.95, paper.

Wine and the Vine: A Historical Geography of Viticulture and the Wine Trade by Tim Unwin New York,NY: Routledge. 1991.Index. 409 pp. ISBN 0-415-03 120-6.     

石羊河流域地下水地球化学特征演化的计算机模拟研究

通过对石羊河流域地下水化学特征的计算机模拟研究表明：武威盆地的部分地区及红崖山水库是白云石和方解石的溶解区,民勤盆地则是白云石和方解石的沉淀区,蒸发浓缩作用是控制这一过程的主要因素。影响武威盆地地下水化学特征的诸因素中降雨起主导作用,而民勤盆地蒸发浓缩起主导作用。SO4^2-／HC03^—比值的上升标志着研究区地下水化学类型由重碳酸盐型向硫酸盐型转化,水质正在不断恶化。     

Sedimentation history of the Selenga Delta, Lake Baikal: simulation and interpretation

The computer simulation of a Lake Baikal seismic profile located in the Selenga River Delta area resulted in a lake level record of the last 600 kyr. This curve demonstrates several low-magnitude episodes and both a dramatic 300 m fall and a more than 150 m increase of the lake level relative to present situation. The greatest change in paleo-lake depth at 300 ka corresponds in time with the major glaciation in the Eastern Siberia and is probably the response of the lake to this climatic phenomenon. The results of this study conform with existing hypotheses on the regional tectonic history and climatic events.     

AN EVALUATION OF SAS/GRAPH SOFTWARE FOR COMPUTER CARTOGRAPHY1

The SAS® computer software system, widely used and respected for its capabilities in statistical analysis and data base management, now includes a new set of graphic and cartographic procedures called SAS GRAPH?. We have used these cartographic procedures in research on mapping ethno-cultural census data from metropolitan areas in Ontario and in undergraduate and graduate courses in computer cartography. On the basis of that experience, we describe and evaluate SAS/GRAPH'S cartographic capabilities and illustrate with maps drawn by various devices.     

基于计算机图形学的土壤质地自动分类系统

国内外通行的国际制、美国农部制等土壤质地分类制, 均采用传统的人工查找平面正三角 坐标图方法获取质地名称, 这对大批量土样费时费力、精度难以控制。结合国外土壤质地计算机 分类方法研究的状况, 本文基于计算机图形学技术, 利用Visual Basic 平台, 设计并完成了更具实 用性、更便于国内使用的土壤质地自动分类系统( STAC) 。STAC 系统的特点是简单、方便、快速、 直观, 具有单个或批量土壤质地的自动分类、图形显示、统计、分析以及支持用户自定义分类制等 多种功能。文中着重阐述了其中的计算机图形学实现原理和关键技术。