Ethnic Enclave Reconfiguration: A ‘new’ Chinatown in the Making

Years of past research on traditional Chinatowns were based on the assumption that Chinatown is an ethnic enclave for a single ethnic minority, i.e. the Chinese. In recent years, one could observe significant changes over Chinatowns in terms of more Vietnamese presence. Yet, the transition process as an object of study is much under-represented in the literature on ethnic enclaves. Looking at ethnic business transition from Hong Kong to Vietnamese in Toronto’s Chinatown West, this paper argues strongly that ‘multiple ethnicity’ can coexist in an enclave. For this case study, the Chinatown is being reconfigured into a ‘new’ Chinatown. Drawing upon data from the authors’ Vietnamese Business Database that covers information between 1983 and 2003, we present both spatial and temporal analyses that offer insights into how the Vietnamese businesses grow through time. Our findings support the existence of a Vietnamization process in Toronto Chinatown West. However, its evolution is still in an infant stage. In some aspects, the incoming Vietnamese businesses display similarities with the remaining Hong Kong businesses. In sum, a total reconfiguration of Chinatown West in form and business nature is still unaccomplished. The conventional enclave concept which bases on the singularity of ethnic group has to be abandoned in view of rising occurrence of ethnic transition, particularly in this globalizing era.     

Ore-forming fluid and mineralization of Caijiaying and Dajing polymetallic ore deposits

Fluid inclusions from the Dajing and Caijiaying deposits have nearly the same ho-mogenization temperature. Correlation between temperature and salinity shows that both Sn-and Cu-bearing fluids Sn and Cu were present in the Dajing deposit but only one kind of fluids continuously evolved in the Caijiaying deposit. Study on rare earth elements (REE) in ancient fluid from the inclusions indicates that the fluid of Sn mineralizing stage in Dajing was derived from remelting magma of the continental crust, and the fluid of Cu-Pb-Zn mineralizing stage in the Dajing deposit and the fluid of Cu-Pb-Zn mineralization in the Caijiaying deposit were derived from the mantle. It is concluded that the Cu-Pb-Zn mineralizations in the Dajing and Caijiaying deposits resulted from the identical tectono-thermal event of magma-fluids induced by Mesozoic tectonic transition and extension in the eastern part of North China Craton.     

New geomorphic evidence for anticlinal growth driven by blind-thrust faulting along the northern Marche coastal belt (central Italy)

The Northern Marche coastal belt is characterised by a series of NW-SE trending, NE verging folds forming the easternmost edge of the Apennines thrust front. Several geomorphic features suggest that the folds are still growing and hence that the thrust front is active. The occurrence of several historical and instrumental earthquakes (e.g. 1672, 1690, 1786, 1875, 1916, 1930, 1972, all having M_e 5.2) suggests that the thrust faults are also seismogenic.We performed a geomorphological analysis to identify and characterise the faults driving the active folds. Our approach assumes that anomalous drainage patterns and deformed Middle-Late Pleistocene alluvial and coastal terraces are indicators of the vertical component of tectonic strain. We identified, mapped and correlated with sea-level fluctuations a sequence of alluvial and coastal terraces. Longitudinal profiles of six rivers (Conca, Foglia, Metauro, Cesano, Misa, and Esino) show that terraces (1) consistently converge downstream, suggesting that they result from regional uplift that dies out near the coast, and (2) some are slightly warped where they cross anticline axes. We interpreted as coastal terraces several land-surface remnants arranged parallel to the present coastline. Lower remnants clearly top off gently landward-tilted coastal deposits. Reconstructed coastal terraces also seem to be tectonically warped.Our results help characterise the geometry and segmentation of a system that generated the largest earthquakes of the region and suggest the loci of potential seismic gaps. We conclude that the earthquake potential of the densely populated northern Marche coastal belt may be substantially higher than currently estimated.     

制度演进与城市旧城区更新活动的实证研究——以武汉市汉正街为例

改革开放以来我国城市旧城区进行了若干次大规模的旧城更新活动,以武汉市汉正街为实证对象,将其更新活动分为3个阶段展开研究,总结分析各阶段国家权力结构调整、土地有偿制度深化和住房制度改革等社会制度环境的变化特征,探讨了社会制度发展在解决旧城问题上所发挥的作用及存在问题。结果表明:制度环境的变迁使旧城更新成为制度容易缺失的领域;制度目标的更迭使旧城更新渐成为公共领域与私人领域的利益争夺舞台;旧城更新的发展过程本质上是公权力与私权利交织的结果。     

嵌入式马尔科夫链的地质属性建模与应用

传统的地质统计学所形成的算法理论和方法(如克里格算法)过分依赖样品的数据,变异函数参数众多,给地质模拟造成很大困难。基于马尔科夫链的地质属性建模采用转移概率描述样品区域的各种参数变量,通过转移概率矩阵直接推导地质属性分布比例、平均长度,其简化了地质空间各向异性处理过程,克服了传统地质统计学中参数众多且复杂难以计算和地质体分布过程中存在不对称性等缺陷,使得整个地质属性建模的过程更简洁、清晰,容易理解,且建模的结果可以很好地反映地质体空间分布的复杂性。该文利用马尔科夫链对南京市河西地区的新近地质层进行了地质属性建模,实例应用表明,使用该模型进行地质属性建模可为进一步的数值模拟提供支持。     

CHANGES OF RIVER BED PATTERN OF A LOWLAND RIVER: EFFECT OF NATURAL PROCESSES OR ANTHROPOGENIC INTERVENTION?

GPR and aerial surveys were conducted to study changes of channel pattern in the lower course of the Obra River (western Poland). The river is an example of an intensive anthropogenic transformation, however, the origin of the river pattern changes in its lower course is not obvious. The GPR measurements were done using a georadar MALÅ ProEx equipped with a shielded 250 MHz antenna. A 3D analysis of the GPR data supported with lithologic information indicated traces of a multi‐channel pattern. A variable orientation of sediment layering within channel bars and differences in channels depth and width pointed to changes of direction of the river bed migration. Analysis of aerial photographs and a satellite image indicated that only a few of the channels inferred from GPR could be discerned. The reason could be the more than 1 m thick fine sands layer covering all the alluvial structures. Analysis of historical maps from the eighteenth and the nineteenth centuries showed that 250 years ago the Obra was a meandering river. The maps illustrate also several meander cutoffs and decreased wetlands surface. The following transformations of the river bed pattern were discerned: 1. From braided to meandering channel pattern which could be a natural process caused by climatic and sediment transport rate changes that was also observed in case of other lowland rivers. 2. From meandering to sinuous pattern with channel islands and then to sinuous with oxbow lakes. However, further research is needed to study reasons and timing of the observed changes.     

北京市低收入人群的居住空间分布、演变与聚居类型

以北京市各街区的低收入人群为研究对象,以2005年和2009年北京市大规模居民调查问卷为基础数据,综合运用数理统计、空间自相关分析和因子生态分析方法揭示北京市低收入群体的属性特征及其空间分布的特点、变化与聚居类型。研究发现:北京市低收入人群中低龄与高龄人口、中低学历及从事劳动密集型行业的人所占比重较高。从空间分布来看,低收入占比较高的街区单元主要分布在城市边缘郊区,并随着城市建设出现向外发展的趋势;与2005年相比,2009年北京市低收入人口出现了初步集聚化特征,西北五环外街道的低收入集聚强度不断提高,同时二环内的低收入集聚强度也有所增加;受CBD快速发展和奥运建设影响,北京市东部和北部的低收入人群比例大幅度降低。最后,本文总结出三类具有代表性的低收入人群聚居类型,分别为本地型、流动型和新移民型。     

北大西洋涛动位相转换的数值研究

借助一个非线性准地转正压模型,模拟了基本西风气流的强弱、不同空间分布的天气尺度扰动涡对北大西洋涛动(NAO)位相转换的作用,以及大尺度双波地形对其的影响.通过一系列的对比试验发现,适当弱的基本西风气流有利于下游系统西退使NAO由正(负)位相转换为负(正)位相;振幅强、活动范围大的天气尺度扰动波是NAO由负位相转换为正位...     

转折性天气降水预报检验方法及应用

采用转折性天气降水检验评估方法,从转折天气预报能力的角度评价了模式降水预报能力。对全球中期T213、日本和德国数值预报模式在2006年9月至2008年8月的降水预报检验评估分析表明:转折天气降水预报能力检验是目前降水检验方法的有效补充。3种模式的转折天气降水预报能力随着预报时效的延长,存在逐渐递减的趋势;短期预报能力分析,T213和日本模式春季最好,而德国模式是夏季最好;48h预报分析,T213和日本模式在长江中下游、华北及东北等部分地区、德国模式在四川盆地和华南部分地区预报效果较好。