Long-Term Regional Landscape Change in the Northern Tequila Region of Jalisco,Mexico

The Tequila Valleys, in Jalisco, Mexico, are well-known in archaeology for an early complex society known as the Teuchitlán tradition (350 b.c.–a.d. 450/500), but later developments have received little attention. Here I report on the first systematic, full-coverage survey of the Tequila region north of the Tequila volcano. I explore the ways in which the societies that occupied this territory experienced sociopolitical change diachronically by investigating settlement scale, integration, complexity, and boundedness. Through the use of these core features, I analyze how each changed in varying ways, resulting in patterns that do not conform to static societal categories. Interestingly, there is no evidence that a large polity controlled the entire region at any point in the sequence. Results indicate a dynamic sociopolitical landscape that did not develop along any predetermined pathway.     

Fluid effect on hydraulic fracture propagation behavior: a comparison between water and supercritical CO2‐like fluid

The initiation of hydraulic fractures during fluid injection in deep formations can be either engineered or induced unintentionally. Upon injection of CO₂, the pore fluids in deep formations can be changed from oil/saline water to CO₂ or CO₂ dominated. The type of fluid is important not only because the fluid must fracture the rock, but also because rocks saturated with different pore fluids behave differently. We investigated the influence of fluid properties on fracture propagation behavior by using the cohesive zone model in conjunction with a poroelasticity model. Simulation results indicate that the pore pressure fields are very different for different pore fluids even when the initial field conditions and injection schemes (rate and time) are kept the same. Low viscosity fluids with properties of supercritical CO₂ will create relatively thin and much shorter fractures in comparison with fluids exhibiting properties of water under similar injection schemes. Two significant times are recognized during fracture propagation: the time at which a crack ceases opening and the later time point at which a crack ceases propagating. These times are very different for different fluids. Both fluid compressibility and viscosity influence fracture propagation, with viscosity being the more important property. Viscosity can greatly affect hydraulic conductivity and the leak‐off coefficient. This analysis assumes the in‐situ pore fluid and injected fluid are the same and the pore space is 100% saturated by that fluid at the beginning of the simulation.     

Village Layout and Social Experience: A Comparative Study from the Northeast Woodlands

This paper examines the spatial configuration of two early fourteenth-century Woodland villages—one composed of longhouses (Nodwell) and one a ring-shaped arrangement of oval huts (Fort Hill). The contrasting spatial layouts of these sites are explored from the perspective of social interaction stress in early villages. Visibility Graph Analysis, a technique for analyzing the relational order of visual fields, is used to measure the properties of spatial integration and control in these settlements over the course of their distinctive occupation histories. Results reveal “top-down” vs. “bottom-up” dispositions toward spatial order that influenced the routine use of settlement space, the nature of village growth, and arguably, long-term trajectories of community development in regional longhouse and ring-shaped traditions.     

计量经济分析方法在国外旅游研究中的应用——基于ATR和TM所载文献的统计分析

本文对国外旅游界最具影响力的两大旅游研究刊物Annals of Tourism Research（ATR）（1974—2005）和Tourism Management（TM）（1980—2005）中运用计量经济分析方法的122篇文献进行了全面回顾。在对计量经济分析方法的构成情况及应用领域进行统计分析的基础上,对其在国外旅游研究中的应用演进情况做了归纳和概括。研究发现,计量经济分析方法正逐渐成为国外学者进行旅游研究的主要手段之一,其中回归模型、时间序列模型和面板数据模型是最常用的手段;方法的应用主要集中在旅游需求研究方面,其次是旅游产业与环境关系研究、旅游供给研究。从研究方法的应用演进来看,经过30多年的发展,从静态的零星运用到比较系统的、动态的多种方法的整合运用,计量经济分析方法在旅游研究中的应用日渐成熟。     

Thermal convection in faulted extensional sedimentary basins: theoretical results from finite-element modeling

Thermal convection has the potential to be a significant and widespread mechanism of fluid flow, mass transport, and heat transport in rift and other extensional basins. Based on numerical simulation results, large‐scale convection can occur on the scale of the basin thickness, depending on the Rayleigh number for the basin. Our analysis indicates that for syn‐rift and early post‐rift settings with a basin thickness of 5 km, thermal convection can occur for basal heat flows ranging from 80 to 150 mW m^?2, when the vertical hydraulic conductivity is on the order of 1.5 m year^?1 and lower. The convection cells have characteristic wavelengths and flow patterns depending on the thermal and hydraulic boundary conditions. Steeply dipping extensional faults can provide pathways for vertical fluid flow across large thicknesses of basin sediments and can modify the dynamics of thermal convection. The presence of faults perturbs the thermal convective flow pattern and can constrain the size and locations of convection cells. Depending on the spacing of the faults and the hydraulic properties of the faults and basin sediments, the convection cells can be spatially organized to align with adjacent faults. A fault‐bounded cell occurs when one convection cell is constrained to occupy a fault block so that the up‐flow zone converges into one fault zone and the down‐flow zone is centred on the adjacent fault. A fault‐bounded cell pair occurs when two convection cells occupy a fault block with the up‐flow zone located between the faults and the down‐flow zones centred on the adjacent faults or with the reverse pattern of flow. Fault‐bounded cells and cell pairs can be referred to collectively as fault‐bounded convective flow. The flow paths in fault‐bounded convective flow can be lengthened significantly with respect to those of convection cells unperturbed by the presence of faults. The cell pattern and sense of circulation depend on the fault spacing, sediment and fault permeabilities, lithologic heterogeneity, and the basal heat flow. The presence of fault zones also extends the range of conditions for which thermal convection can occur to basin settings with Rayleigh numbers below the critical value for large‐scale convection to occur in a basin without faults. The widespread potential for the occurrence of thermal convection suggests that it may play a role in controlling geological processes in rift basins including the acquisition and deposition of metals by basin fluids, the distribution of diagenetic processes, the temperature field and heat flow, petroleum generation and migration, and the geochemical evolution of basin fluids. Fault‐bounded cells and cell pairs can focus mass and heat transport from longer flow paths into fault zones, and their discharge zones are a particularly favourable setting for the formation of sediment‐hosted ore deposits near the sea floor.     

司徒美堂与抗日战争

美洲著名爱国侨领司徒美堂为祖国抗战做出了重大的贡献。他从九一八事变后即率先投身于抗日救亡运动,积极声援自发奋起抗战的国民党官兵;全国抗战爆发后,他出任抗日救国侨团的首领,带领广大华侨开展抗日救亡活动;他万里迢迢回国慰劳抗日军民,为祖国抗战出计献策,在途经香港陷入日军魔掌的危险时刻,表现出了铁骨铮铮的民族气节;他团结美洲洪门侨胞,报效祖国抗战,使这一古老的帮会组织焕发青春;他呼吁祖国团结抗战,反对妥协投降,有力地维护了国共合作抗战的大局。他是广大华侨抗日救国的领袖和楷模,其爱国思想在支援祖国抗战中进一步得到升华。     

Complexity science and human geography

Complexity science has attracted considerable attention in a number of disciplines. However, this perspective on scientific understanding remains ill defined. In this paper, ideas and approaches from complexity science are reviewed. It appears that complexity science fundamentally is driven by ontological decisions on the part of the investigator. This is a result of the epistemological approach fundamental to complexity as it is currently studied, which is based on the construction of computer simulation models of reality. This methodology requires that researchers decide what exists and is important enough to represent in a simulation, and also what to leave out. Although this points to serious difficulties with complexity science, it is argued that the approach nevertheless has much to offer human geography. Drawing on complexity science, renewed engagements between physical and human geography, and between both and geographical information science seem possible, based on clearly shared concerns with the representation of geographical phenomena. In conclusion, it is suggested that seeing models as a source of geographical narratives may be a useful way to promote constructive engagement between different perspectives in the discipline.