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1.
In recent decades the Uruk and Jemdet Nasr periods of the fourth millennium B. C. in Mesopotamia have been the subject of considerable research by scholars of the ancient Near East. Interests in and interpretations of these periods have focused on their credentials as early states, urban societies, and the immediate antecedents of Sumerian civilization. In this overview, I first present a brief historical background on the study of these periods, followed by a critical review of recent approaches that have had significant impacts on current directions of research and understanding of the fourth millennium. Finally, I suggest some research avenues currently being tentatively explored that may be especially appropriate for developing further our understandings of these periods.  相似文献   
2.
J. P. FAIRLEY 《Geofluids》2009,9(2):153-166
Previous studies have shown that most hydrothermal systems discharging at the land surface are associated with faulting, and that the location, temperature and rate of discharge of these systems are controlled by the geometry and style of the controlling fault(s). Unfortunately, the transport of heat and fluid in fault-controlled hydrothermal systems is difficult to model realistically; although heterogeneity and anisotropy are assumed to place important controls on flow in faults, few data or observations are available to constrain the distribution of hydraulic properties within active faults. Here, analytical and numerical models are combined with geostatistical models of spatially varying hydraulic properties to model the flow of heat and fluid in the Borax Lake fault of south-east Oregon, USA. A geometric mean permeability within the fault of 7 × 10−14 m2 with 2× vertical/horizontal anisotropy in correlation length scale is shown to give the closest match to field observations. Furthermore, the simulations demonstrate that continuity of flow paths is an important factor in reproducing the observed behavior. In addition to providing some insight into possible spatial distributions of hydraulic properties at the Borax Lake site, the study highlights one potential avenue for integrating field observations with simulation results in order to gain greater understanding of fluid flow in faults and fault-controlled hydrothermal and petroleum reservoirs.  相似文献   
3.
The new interest in cultural landscapes is forcing a reappraisal of concepts of countryside heritage. First the traditional split between cultural and natural values is challenged. Second, modern landscape studies emphasise the subjectivity of landscape assessment, and this is subverting the former tendency to aspire to objectivity in evaluation. The acceptance of ‘associative’ value in landscape is an indicator of this. Modern landscape studies also emphasise the interrelationships between processes and aspects of value, and this is encouraging specialists to communicate across disciplinary frontiers. The desire by ecologists in the mid‐1980s to have cultural landscapes inscribed on the World Heritage list caused a re‐assessment of the World Heritage Criteria, and an initiative by ICOMOS brought this process to a conclusion in 1992. However the reappraisal of concepts of countryside value imply that there are many other philosophical and practical matters still to be resolved.  相似文献   
4.
    
Since the availability of cheap and suitable energy underpins in many ways both developed and developing economies, it is crucial that national economies are prepared for potential energy shocks. Shocks may arise from physical constraints, such as a peak in the national and global production rate of oil, or from institutional constraints, such as economic incentives to reduce greenhouse gas emissions. This article reviews the potential and implications of alternative energy technologies intended to avoid or alleviate such shocks. It is suggested that system-wide analysis is required to properly assess all alternatives.  相似文献   
5.
Courtly love appeared in twelfth‐century Europe as a dissent from the emotional regime established by the Gregorian Reform, by setting the lady, instead of God, as the object of worship. From a game‐theory perspective, courtly love and hedonism correspond to Nash equilibria, in contrast to Christian marriage, whose stability is threatened by sex‐as‐appetite on one side and devotion to God on the other, and whose maintenance depends on moral control. The Church developed fear and shame, which are counter‐emotions to desire‐as‐appetite. Courtly love restored the thrill of forbidden adventure. It also shared traits common to innovations in the natural world: it added complexity (by increasing costs, emphasizing courtship, self‐restraint, and extremes of suffering); it was made possible by the plasticity of mating relationships; it introduced a small disorder in the ordered regime of Christian marriage; it demanded an adaptive effort, requiring the man to face ever more perilous trials and the woman to appear ever more attractive. Though obtained as a small deviation from the existing emotional regime, it had thoroughgoing and long‐lasting consequences for social control and for the political power of the Church. It also deeply modified the dynamic of longing in ego's representation. By taking the temporal form of a capture, it contrasts with twelfth‐century Bengal, where love was characterized by maintenance in an indefinitely repeating worship, by the absence of a here‐now versus target‐later dualism. It also contrasts with eleventh‐century Heian Japan, where love was intermingled with the melancholy of an impossible return, which is the antithesis of the concept of capture.  相似文献   
6.
十一届三中全会前夕对外开放的酝酿和起步   总被引:1,自引:0,他引:1  
中共十一届三中全会确立了对外开放的基本国策,而1976-1978年对外开放的酝酿和起步是十一届三中全会确立对外开放政策的前提和基础。1977年3月的全国计划会议和1978 年7-9月的国务院务虚会,使全党在对外开放问题上达成了一致,为后来的对外开放的实践创造了坚实的理论基础。  相似文献   
7.
In recent years, cultural anthropologists have made notable progress in understanding the bewildering variety of material exchange transactions found among the aboriginal populations of highland New Guinea. One of the major findings of this work is that competitive exchange behavior may bring in its wake alterations in agronomic practices involving an intensification of production. That intensification is primarily a product of social behavior, rather than an adaptation to climate change or population pressure, is a significant conclusion that should influence the thinking of archaeologists as they investigate past episodes of agronomic change, including the origins of agriculture.  相似文献   
8.
Scale remains a pivotal yet highly contentious concept in geography. I survey the lively discussions engaged in recently by many critical/radical geographers regarding the theoretical status of scale. While these discussions have been intellectually fruitful, I argue that much more needs to be said. Drawing from complex systems theory, I argue that scale should be understood as an ontological category essential to understanding causality. Revalorising Aristotle's four categories of cause – formal, final, material and efficient – from two centuries of positivist thinking facilitates this endeavour. Research on the relationship between university-based poultry scientists and the poultry industry illustrates the explanatory potential of poly-scalar analysis.  相似文献   
9.
The field system of the Wadi Faynan in southern Jordan was fed by an ancient combination irrigation system that incorporated runoff farming and diversion irrigation techniques. The hydraulic characteristics of this system were most probably designed to take advantage of the confluence of three tributary streams. A theoretical model of discharge produced by runoff is based on contemporary ground conditions and historic climate reconstructions. The design principles of the main hydraulic features are examined and velocity and discharge measurements in principal conveyance irrigation channels are reconstructed. The design of this hydraulic system took into account the environmental constraints and opportunities of the area and maximized different sources of water in the catchment using various techniques of water collection.  相似文献   
10.
Excavated human bone was exposed to aqueous solutions containing high concentrations of a single added metal ion in order to examine the extent of introduction of contaminating materials during burial. Variables included pH, temperature, ion concentration, state of bone (whole or crushed), structure of buffer, and counterion. Calcium and sodium showed little increase, and even a decrease in some cases. Strontium, zinc, lead, and magnesium showed large increases probably through heteroionic replacement of calcium. Manganese, aluminum, and potassium showed increases, particularly under neutral conditions, probably through infiltration into voids and defects.  相似文献   
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