基于VC++,MapInfo和Oracle Spatial的GIS应用系统开发

在现有地理信息系统(GIS)平台上进行应用系统的二次开发是最常见的一种开发方式。本文主要介绍了在VC ,MapInfo和Oracle Spatial环境下,集成开发GIS应用系统的方法,包括在VC 环境下嵌入MapInfo,调用MAPBASIC命令,连接、操纵存储在Oracle Spatial中的空间和属性数据等。最后结合具体应用实例。对上述方法进行了阐述和验证。     

EH4电磁成像系统在高速公路长大深埋隧道勘察中的应用研究

EH4电磁成像系统是一套双源型电磁法数据自动采集和处理的物探系统,它是CSAMT和MT的结合体。本文介绍了EH4的原理、特点、工作方法和资料处理。该系统首次运用于高速公路长大深埋隧道勘察中,结合其他手段,成功解译出了隧道的软弱层、地下水及断层破碎带的位置,为划分隧道围岩类别提供了较好的依据,同时也为高速公路长大深埋隧道提供了一种新的勘察方法。     

Exploring the disc/jet interaction in the radio-loud quasar 4C+74.26 with Suzaku

We report on a 90 ks Suzaku observation of the radio-loud quasar 4C+74.26. The source was observed in its highest flux state to date, and we find that it brightened by about 20 per cent during the observation. We see evidence of spectral hardening as the count rate increases and also find that the rms variability increases with energy up to about 4 keV. We clearly detect a broadened Fe line but conclude that it does not require any emission from inside about 50 r _g, although a much smaller inner radius cannot be ruled out. The large inner radius of our best fit implies that the inner disc is either missing or not strongly illuminated. We suggest that the latter scenario may occur if the power-law source is located high above the disc, or if the emission is beamed away from the disc.     

A systematic look at the very high and low/hard state of GX 339−4: constraining the black hole spin with a new reflection model

We present a systematic study of GX 339−4 in both its very high and low hard states from simultaneous observations made with XMM–Newton and RXTE in 2002 and 2004. The X-ray spectra of both these extreme states exhibit strong reflection signatures, with a broad, skewed Fe Kα line clearly visible above the continuum. Using a newly developed, self-consistent reflection model which implicitly includes the blackbody radiation of the disc as well as the effect of Comptonization, blurred with a relativistic line function, we were able to infer the spin parameter of GX 339−4 to be  0.935 ± 0.01  (statistical) ±0.01 (systematic) at 90 per cent confidence. We find that both states are consistent with an ionized thin accretion disc extending to the innermost stable circular orbit around the rapidly spinning black hole.     

淡水和海水环境下沉积物搬运过程碳释放通量的模拟研究

基于室内物理模拟实验, 对长江沉积物进行淡水和海水环境下沉积物搬运过程碳释放通量实验模拟。结果表明, 模拟实验初期, 淡水和海水均为大气CO₂的源, 但淡水CO₂释放通量略高于海水;淡水、海水两种环境下, CH₄释放通量均较小, 为弱释放-弱吸收过程。对两种环境下碳通量对比研究发现,Eh 值可能是造成淡水和海水环境下CO₂通量差别的主要原因, 而pH 值可能对CO₂通量差别的影响较小。两种环境下温室气体通量差别的具体原因仍需进一步研究。通过模拟对比试验, 旨在为系统地认识长江流域水库的温室效应与减排提供科学依据, 为我国清洁水电能源发展提供理论参考。     

RICE PRODUCER‐PROCESSOR NETWORKS IN CÔTE D'IVOIRE*

ABSTRACT. Pressured by structural adjustment loan conditions, Côte d'Ivoire reduced state support for rice production and processing during the 1990s. In this article we examine how various actors in the rice commodity chain adapted to the macroeconomic reforms. Following a brief history of the rice sector, we present the results of fieldwork based on interviews conducted in 2002 of farmers, millers, traders, and workers in the state extension service and nongovernmental organizations. We found that, in the absence of state supports for farmers, private millers became the focal point of regional producer‐processor rice networks. The four networks identified became the sole source of domestic commercial rice when the state removed subsidies for fertilizer and modern seeds, privatized extension, and liberalized prices and imports. To increase their role in the national rice supply, the rice networks may need support through microlending and a focus on niche markets.     

Hydropower – A Green Energy? Tropical Reservoirs and Greenhouse Gas Emissions

Reservoirs are man‐made lakes that severely impact on river ecosystems, and in addition, the new lake ecosystem can be damaged by several processes. Thus, the benefits of a reservoir, including energy production and flood control, must be measured against their impact on nature. New investigations point out that shallow and tropical reservoirs have high emission rates of the greenhouse gases CO₂ and CH₄. The methane emissions contribute strongly to climate change because CH₄ has a 25 times higher global warming potential than CO₂. The pathways for its production include ebullition, diffuse emission via the water‐air interface, and degassing in turbines and downstream of the reservoir in the spillway and the initial river stretch. Greenhouse gas emissions are promoted by a eutrophic state of the reservoir, and, with higher trophic levels, anaerobic conditions occur with the emission of CH₄. This means that a qualitative and quantitative jump in greenhouse gas emissions takes place. Available data from Petit Saut, French Guinea, provides a first quantification of these pathways. A simple evaluation of the global warming potential of a reservoir can be undertaken using the energy density, the ratio of the reservoir surface and the hydropower capacity; this parameter is mainly determined by the reservoir's morphometry but not by the hydropower capacity. Energy densities of some reservoirs are given and it is clearly seen that some reservoirs have a global warming potential higher than that of coal use for energy production.     

开发地震技术及进展

地震技术经过多年的发展,已经成为寻找石油和天然气的重要手段.并且正逐步向油气开发及生产领域渗透.出现的新技术主要包括：3D地震、垂直地震剖面、井间地震、时间推移地震、多波多分量地震、微地震检测、随钻地震等新技术.这些技术在国内各油田日益受到重视,在应用中取得了较好效果,为油田增储上产做出了重要贡献.对地震技术的形成过程作了简单回顾并着重对开发地震技术进行了介绍和归纳,同时对今后的发展方向进行了探讨.     

四分量钻孔应变观测资料的换算和使用

水平四分量钻孔应变仪观测的是地表附近一点的水平应变变化. 但是其直接记录并非应变变化,应根据互检条件先进行实地相对标定(计算元件校正系数),然后用理论固体潮进行实地绝对标定(计算探头校正系数),才能进行应变换算,给出可作为应变变化使用的数据. 因为钻孔应变仪观测的是应变变化,所以实地标定和应变换算都需要用增量. 对于精确的研究,这些校正系数都可能随时间变化,因而需要根据具体问题按特定时间段对校正系数进行计算. 该文比较系统地说明了四分量钻孔应变观测资料换算和使用的基本步骤和具体方法,并以姑咱台的观测资料为例,给出了具体分析结果.