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981.
A new instrument has beendeveloped to measure the total decay rate of OH in ambient air. Theinstrument is based on the discharge flow technique in which OHgenerated within the instrument is reacted with ambient air pulled intothe flow tube. The OH decay is monitored by laser-induced fluorescence. Thistotal decay rate is compared to the sum of the individual decay rates ofOH with each trace species measured in the air to test for missing OHreactants. OH decay rates measured in an urban environment in thesummer of 1999 illustrates the promise of this technique.  相似文献   
982.
Earthquake risk assessment for Istanbul metropolitan area   总被引:2,自引:2,他引:2  
The impact of earthquakes in urban centers prone to disastrous earthquakes necessitates the analysis of associated risk for rational formulation of contingency plans and mitigation strategies. In urban centers, the seismic risk is best quantified and portrayed through the preparation of “Earthquake Damage and Loss Scenarios.” The components of such scenarios are the assessment of the hazard, inventories and the vulnerabilities of elements at risk. For the development of the earthquake risk scenario in Istanbul, two independent approaches, one based on intensities and the second on spectral displacements, are utilized. This paper will present the important features of a comprehensive study, highlight the methodology, discuss the results and provide insights to future developments.  相似文献   
983.
香港历史地理的变迁   总被引:3,自引:0,他引:3  
司徒尚纪 《热带地理》1997,17(2):203-211
本文在复原香港古代文明和地方建置基础上,阐明香港自古以来即为中国领土,鸦片战争以后被英国实行殖民统治的空间扩张过程、市镇发展、经济崛起、特殊政治舞台和特殊文化风格等历史地理变迁;指出香港成为世界性经济大都会,主要因素在于香港区位、华人资本、人力、技术流入、机遇,以及中国人民刻苦经营和辛勤劳动结果,而不是英国殖民主义胜利。  相似文献   
984.
The pattern of relative denudation at the soil-bedrock interface over a wooded Magnesian Limestone hillslope was investigated using micro-weight loss bedrock tablets. The resulting pattern of weight loss after emplacement for one year indicated a consistent upslope increase in solutional denudation. Results from tablets emplaced for two years confirmed this. Dye tracing and gypsum sphere weight loss results showed that water movement over the slope was by vertical percolation and not by throughflow. The pattern of solutional denudation was related to changes in soil type and associated changes in soil pH. Continued slope development by solutional denudation will ultimately lead to slope decline. Comparison with a similar study suggests that a general soil chemistry based model of hillslope solutional denudation can be proposed.  相似文献   
985.
ABSTRACT

What is successful migration? At a macro-socio-political level migration by individuals may appear to be successful when it has met the objectives of governments, industries and domestic profit makers. However, delving beneath the surface can reveal contradictions and other measures of success at the individual, or micro-level. Within a broader critical historical ethnography, we interviewed 26 post-World War 2 (WW2) British migrants living in South Australia. All interviewees could be viewed as successful at the macro-level, having remained in Australia for many years and having established multi-generational Australian families. Their migration was a ‘success’ when measured against the priorities that were actively promoted by Australian governments in the post-WW2 period. At a micro-level, the migrants involved in this study reported mixed outcomes. While migration did result in self-identified aims of migration including employment, opportunities and adventure, some migrants reported high levels of distress and longing, linked to loss and dislocation from people and places in geographically distant locales. For some, these feelings extended into the present, raising questions over the ‘success’ of their migration experiences at a personal level. We argue that pro-active migration recruitment—such as that undertaken by Australian governments in the post-WW2 period—has the potential to pressure some persons into migration, creating ongoing and unresolvable tensions. Experiences of such disruptions merit further exploration to develop deeper critical understandings of migration success.  相似文献   
986.
大庆油田防震减灾信息管理系统建设   总被引:1,自引:2,他引:1  
近年来,GIS技术被广泛地应用于城市或区域的防震减灾信息管理系统的建设。本文着重论述了大庆油田有限责任公司防震减灾信息管理系统的建设,以及建成后的系统所包含的主要内容和所能实现的功能。应用GIS技术建设大型企业防震减灾系统是一个新的尝试,所完成的系统不但能对企业在地震应急中起到辅助决策作用,而且对于日常管理也是十分方便的。该系统的运行为大型企业防灾系统的建设提供了思路和借鉴。  相似文献   
987.
Results from the measurement of microweight loss of Magnesian Limestone rock tablets placed at the soil–bedrock interface on a hillslope over 10 years (1982–1992) gave the same relative pattern of upslope increase in weight loss as did short-term measurements (1979–1981), but the absolute values were an order of magnitude lower (0·01–0·03 per cent per year long term and 0·1–0·6 per cent per year short term). Microweighed rock tablets may therefore give unreliable absolute rates and can only be used to indicate relative spatial differences rather than to give reliable data on temporal changes.  相似文献   
988.
李平 《地质科技情报》1993,12(4):97-101
对未来发生地震可能造成的经济损失进行预测,是各个地区政府部门进行经济建设规划的一项必不可少的基础性工作。本文着重分析了影响地震灾害损失的因素,提出了定量计算地震灾害经济损失严重性的数学模式。  相似文献   
989.
The ionizing star BD+60°2522 is known as the central star of Bubble Nebulae NGC 7635—wind-blown bubble created by the interaction of the stellar wind of BD+60°2522 (O6.5 IIIef, V=8.7 mag, mass loss rate 10−5.76 M /year) with the ambient interstellar medium. From the evolutionary calculations for the star with mass loss and overshooting, we find that the initial mass of the star is 60M , its present age is 2.5×106 years, and the present mass is 45M .  相似文献   
990.
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