TUNING OF SEISMIC HAZARD ESTIMATES BY MEANS OF OBSERVED SITE INTENSITIES

Probabilistic seismic hazard is usually assessed by means of computer codes using seis-mogenic sources, parametric catalogues, seismicity rates and attenuation relationships. All these ingredients are conditioned by expert judgement that influences the final results. Even the attenuation relationships, though strictly based on experimental data, are considered a weak point due to the difficulty of modelling the interaction between seismic energy radiation and site response, and because earthquakes do not usually repeat themselves according to one theoretical model. Recently, methods making wide use of site intensity data have been developed in regions such as Italy, where the observed seismic history at selected sites is quite exhaustive. We analyzed these observations to assess seismic hazard at about 600 sites. We used a probabilistic counting technique, integrating the observations (when necessary), with computed shakings obtained from a logistic-type attenuation model. The results were then compared with the estimates provided by the recent seismic hazard map of Italy, compiled according to the traditional probabilistic seismic hazard approach. The match shows significant differences for some sites. A tentative explanation which seems to point to three alternatives is provided: (1) The mismatch between the two methodologies might appear because the stationary assumption has a poor fit with reality (at least in certain areas); (2) Some sites show a response that is systematically different from the average values predicted using attenuation relationships; (3) The definition of seismogenic zones leads to a bias in the seismicity rate estimate.     

俄罗斯的亚太战略与政策探析

俄罗斯作为苏联解体后的当然继承国,成为当今世界政治经济格局多极化发展趋势中重要的一极。目前俄罗斯承袭了苏联后期的亚太战略,并在某种程度上使其有所发展。本文在分析苏联后期实施亚太战略与政策的基础上,着重探讨了俄罗斯目前实施亚太政治经济战略的新东方政策与措施,并对其远东同亚太各国的经济联系的近期态势进行了实证分析;论述了中俄关系对实施其亚太战略的重要性;指出中俄建立面向21世纪的战略协作伙伴关系完全符合两国各自的地缘经济利益。     

城市群对外服务功能量化解析——以山东半岛、中原和关中三城市群为例

城市流强度描述了城市对外联系的强弱。是表征城市对外服务功能的量化指标。三个省份的实证检验明显地揭示出城市流与城市中心性具有特别强的相关性。本文以山东半岛、中原和关中城市群为研究区域,通过城市流强度的计算与结构的分析,从城市流视角探讨城市群发展演化机理,揭示出城市群空间结构由简单的单核心结构到复杂的多核心结构的演化过程。文章根据城市流大小和及其产业分布情况,分析了城市群及其中心城市的二、三产业城市流强度与结构,得出城市群整体的对外服务特征,并据此提出改善和提高城市对外服务功能的措施。     

国外对零售业及其附生——衍生的营业性娱乐场所的空间关系研究

零售业及其附生-衍生的营业性娱乐场所是城市居民日常生活(闲暇娱乐)行为的四大场所之一,零售业中附生-衍生的娱乐场所的类型、结构与空间模式是揭示城市社会-生活空间质量的重要方面,本文从城市社会地理学以及人类文化生态学等多学科的研究角度,分析与总结国外学者对零售业及其附生-衍生的营业性娱乐场所的研究现状、内容以及其在城市中的空间作用与(社会)空间关系。     

《山东考古录》与《日知录》之关系考述

关于《山东考古录》和《日知录》的关系 ,《四库全书总目提要》及《续山东考古录》刘椿序皆认为二者了无相关之处。但通过对《山东考古录》和《日知录》材料的综合分析 ,可以认定《日知录》吸收了《山东考古录》中的许多材料 ,《山东考古录》中的若干内容可视为《日知录》初稿中的一部分。     

FT-IR measurements of petroleum fluid inclusions: methane, n-alkanes and carbon dioxide quantitative analysis

A recent advancement in petroleum geochemistry is to model fossil oil composition using microthermometric and volumetric data acquired from individual fluid inclusion analysis. Fourier transform infrared (FT‐IR) microspectroscopy can record compositional information related to gas (CH₄ and CO₂) and alkane contents of petroleum inclusions. In this study, a quantitative procedure for FT‐IR microspectrometry has been developed to obtain, from individual fluid inclusions, mol percentage concentrations of methane, alkanes and carbon dioxide as constraints to thermodynamic modelling. A petroleum inclusion in a sample from the Québec City Promontory nappe area was used as standard to record a reference spectrum of methane. The analytical procedure is based on the measurement of CH₄/alkane and CH₄/CO₂ band area ratios. CH₄/alkane infrared band area ratio is obtained after spectral subtraction of the reference methane spectrum. This area ratio, affected by absolute absorption intensities of methane, methyl and methylene, provides a molar CH₄/alkane ratio. Methyl/methylene ratio (CH₂/CH₃) ratio is obtained following procedures established in previous work. CO₂/CH₄ concentration ratio is estimated from relative absolute absorption intensities. Application to natural inclusions from different environments shows good correlation between FT‐IR quantification and PIT (petroleum inclusion thermodynamic) modelling.     

‘Torrents of Terror’: the August 1998 Storm and the Magnitude,Frequency and Impact of Major Floods in the Illawarra Region of New South Wales

The Illawarra Region some 80 kilometres south of Sydney is characterised by a prominent coastal escarpment that rises to 700 m within 12 km of the coast and forms a locus for frequent, high intensity rainfall events. One of the most recent recorded events occurred on 17 August 1998 with rainfall intensities at several pluviometers exceeding 120 mm hr^‐1 over a duration of one hour, with up to 249 mm falling in 3.5 hours during the main storm burst. Detailed pluviometer data indicate that the storm was non‐stationary and moved down catchment producing a widespread zone of 120 mm hr^‐1 intensity rainfall over a 30 minute duration across mid‐lower catchment areas after similar intensity but longer duration rainfall in catchment headwaters. Slope‐area reconstructions of peak discharge indicate that small catchments on the escarpment within the zone of maximum intensity experienced close to 100% rainfall‐runoff relationships, with peak discharges correlated to short duration (<1 hr) peak rainfall intensities. Widespread erosion occurred particularly where urban development had encroached on natural water courses. Debris/hyperconcentrated flows originating from both anthropogenic and natural sediment sources caused damage to urban areas. This paper provides an overview of the spatial and temporal characteristics of the 17 August 1998 storm, the hydrologic and geomorphic response of the streams, and the nature of damage to urban areas. It reassesses the frequency of recent high‐magnitude rainfall/flood events in the region, discussing the relationships between rainfall intensities, estimates of flood magnitudes and stormwater channel capacities.     

黑龙江省东部城市密集区城市流强度分析

本文在对现有城市流理论进行疏理的基础上提出强化城市流模型,依据城市流强度值的计算,将黑龙江省东部城市密集区的城市分为三级:城市流强度值较高的佳木斯,是该区域的集聚辐射中心,为区域性中心城市;城市流强度值中等的牡丹江,是区域次级集聚辐射中心,为次级区域性中心城市;鹤岗、双鸭山、鸡西、伊春、七台河等市有较低的城市流强度值,城市的集聚与辐射功能微弱,初步形成地方集聚辐射中心,仅为行政区中心。通过各城市的城市流强度分析,指出黑龙江省东部城市密集区目前存在城市流强度低、城市流强度结构不合理等问题,并运用本文提出的强化城市流模型给出区域强化城市流的对策。     

《劳动合同法》对导游用工涉及的法律关系的影响

本文通过对比分析《劳动合同法》颁布前后导游与旅行社、导游服务公司之间的法律关系,认为导游与旅行社或导游服务公司之间成立劳动关系,原先受民法调整的劳务关系将渐渐从导游执业中淡出,导游权益的保障会有一定程度的改善。     

对青海非公有制企业社会保障和劳动关系的调查与思考

新时期,青海非公有制企业的社会保障和劳动关系表现出一些新情况和新特点。笔者在进行社会调查的基础上,分析了存在的问题及原因,并就新形势下构建和谐的劳动关系提出了若干建议。