首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Many long‐standing debates about anachronistic concept‐attributions derive from an essentialist understanding of concepts that is often difficult to sustain for metaphysical or epistemological reasons. The intentionalist alternative to essentialism elaborated in this article successfully clarifies and avoids many standard problems with anachronism.  相似文献   

2.
3.
Recent studies of the thermal histories of archaeological materials with electron spin resonance (ESR) spectroscopy have been extended to black materials encountered in archaeology and in the conservation of antiquities. The ESR parameters of jet. charcoal and lampblacks are reported and comparisons made with a range of related materials Discrimination and characterization is achieved by simultaneous consideration of the three main parameters of the ESR signal due to radical carbon. This study is the first attempt using ESR spectroscopy to discriminate between jet and related coal-like substances.  相似文献   

4.
The first of two papers on the problem of forecasting the level of the Caspian Sea evaluates factors widely believed to have been responsible for its lowering during much of the present century (including tectonic movements, climatic cycles, human activity). It concludes that previous forecasts have been inaccurate because of the failure to adequately model the complexity of processes involved, specifically the internal mechanisms of “self-regulation” of water levels. Continuation of the recent slight rise in the Caspian's level is predicted at least into the early 1990s (translated by Andrew R. Bond).  相似文献   

5.
Although concave-bank benches rarely occur in freely meandering rivers, they may constitute a significant proportion of the floodplain formed by the downvalley migration of the tight channel bends of confined meanders. This study reports the results of a field survey of the floodplains of Fort Nelson and Muskwa rivers, two of many northeastern British Columbian rivers whose meandering is confined between the resistant valley sides of former glacial meltwater channels. The formation and character of contemporary concave-bank benches and the morphology and sediments of the corresponding floodplain features are described. The concave-bank benches form lateral ribbons of deposition along the valley walls and constitute about one-third of the entire floodplain.  相似文献   

6.
The core of this paper seeks to make a methodological contribution to the GIS-based analysis of visibility as a potential locational factor in past landscape placement, an area of study whose utility and value have been hotly debated by archaeologists keen to promote more experiential approaches to the interpretation of past landscapes. In doing so it seeks to break with recent discussions on the topic by not show-casing new or technically more sophisticated sets of approaches. Instead it backtracks to reclaim a methodology introduced over a decade ago, yet rarely applied in routine archaeological practice – a case of taking one step back to advance two steps forward. An important subtext is that for the utility of GIS-based work to be appreciated, it has to be driven by a clear archaeological research programme. To this end the study is fully embedded in a current research initiative exploring the megalithic monuments of prehistoric Alderney, the northernmost of the Channel Islands.  相似文献   

7.
The study of oceans as a subfield of geography has gained acceptance in the Soviet Union. Some universities have introduced courses in marine geography, and geographers have participated in oceanographic research voyages. An effort is made here to define the place of a marine geography within the geographic discipline as a whole, to set the spatial limits for geographical investigations of the oceans and to suggest problem areas suitable for geographical analysis. In keeping with the Soviet dichotomy, physical and economic geographic problems are distinguished. Physical-geographic problem areas would include study of oceanic water masses; large-scale interaction between oceans and atmosphere; study of island environments, and the biogeography of oceans. Economic geographic problems would focus both on theoretical aspects, such as spatial regularities in human activities related to oceans, and on applied aspects, providing a sound basis for economic development of ocean areas.  相似文献   

8.
Both the growing body of literature on the tree-ring calibration of radiocarbon dates, and the variety of statistical approaches used, make it appropriate to review the basic principles involved in the construction of a calibration curve. While its ultimate validity is in part a geophysical problem, the appropriate form for the calibration function, given a specific body of data, is a statistical question centering upon the analysis of the measurement errors involved. The relationship between the calibration function and the inverse calibration function is examined, and the shortcomings of the available published calibration curves considered in the light of this examination. It is concluded that there is no reason to doubt the general principles on which the calibration is based, but a need exists for a more critical handling of the measurement data with a statistical treatment of the errors involved. The quality of the data could itself be improved by the use of replicate samples for inter-laboratory projects specifically designed to investigate the magnitude of measurement error.  相似文献   

9.
Three lipid analysis methods were applied to extracts of archaeological potsherds from the ancient city of Sagalassos, south‐west Turkey. In the fatty acid methyl ester fraction, obtained by selective transesterification of acylglycerols, the ratio of methyl palmitate to methyl stearate was determined. Secondly, by means of gas chromatography– combustion–isotope ratio mass spectrometry (GC–C–IRMS), stable carbon isotope ratios were measured for the same methyl esters. Finally, triglyceride composition was determined via high‐performance liquid chromatography–mass spectrometry (HPLC–MS). All three methods can be used to trace the origin of animal fat. Agreement between them is reasonable, especially in recognizing ruminant adipose fat. One sample was found to be of dairy origin using both GC–C–IRMS and HPLC–MS. The advantages of the various methods are discussed. Variations in lipid composition were observed between samples from different periods and excavated in diverse areas within the city of Sagalassos.  相似文献   

10.
A review of population trends in the USSR and in East Siberia suggests that net in-migration will become a negligible source of labor over the next 25 years until the year 2000 because past labor surpluses no longer exist in the western regions of the Soviet Union and because living conditions in the eastern regions are inferior to conditions in the west. East Siberia will therefore have to depend increasingly on the regional rate of natural increase. The region's population is expected to grow from 8 million in 1970 to 10–12 million by the year 2000. The slow predicted growth of population is not expected to become a constraint on the region's economic development because of rising labor productivity and a regional emphasis on energy-intensive and raw-material-oriented industries rather than labor-intensive activities.  相似文献   

11.
Titanium and calcium in ceramic materials can be analysed by neutron activation using a number of radioisotopes. Historical usage of scandium-47 for the analysis of both elements is reviewed. Measurements were made of the production and decay of 47Sc sources prepared by SLOWPOKE reactor irradiations of pure titanium and calcium salts. Relative interferences were established and their effects calculated for a range of ceramic types. This study indicates that published values of the concentrations of titanium and calcium, using 47Sc, must be seriously reassessed.  相似文献   

12.
潘玲 《考古学报》2008,(3):311-336
鹿石是大部分表面雕刻有以鹿为主的动物形象和武器工具形象的拟人化石柱,因雕刻的动物形象大多数是有固定造型特征的鹿(俄罗斯学者称之为风格化的鹿),因此把这类石柱统称为鹿石。鹿石主要分布于蒙古共和国,其中西部省份分布最密集。与蒙古接壤的俄罗斯外贝加尔地区以及图瓦和阿尔泰地区、中国的新疆地区有少量分布,哈萨克斯坦共和国东部、俄罗斯东欧部分以及西到德国易北河流域也零星分布极少量与鹿石类似的石雕像。鹿石常竖立  相似文献   

13.
It has been established that on occasion prehistoric man heat-treated siliceous stones in order to improve their flaking qualities. In this work we have examined samples of heat-treated chert by means of X-ray diffraction and have established that, in most cases, heat treatment causes an X-ray diffraction line broadening which can be interpreted as a decrease in range of crystalline order of up to 40%, in the most extreme case. The implications of this to an understanding of the fundamental mechanisms of fracture and as a tool for archaeological studies are discussed.  相似文献   

14.
The success of government efforts to stimulate energy conservation among the public ultimately depends on understanding patterns of energy consumption, perceptions of energy resources, and the adoption of conservation practices. These issues were addressed in a survey of residents of Edmonton and Calgary. Most respondents dismissed the seriousness of energy problems at the provincial level, although energy scarcity at the national and global scales was widely recognized. Conservation behaviour was characterized by a narrow range of adjustments perceived and adopted, attributable largely to patterns of resource perception and socio-economic factors.
La réussite des efforts gouvernementaux pour stimuler les conservations d'energie dépend, en dernière analyse, d' une compréhension des schémas de la consommation énergétique, desperceptions des resourcesénergétiques, et del'adoption d' habitudesconservatrices. On a interrogé les habitants d' Edmonton et de Calgary ace sujet. La plupart des réponses ignorent la gravité des problèmes d'énergie au niveau provincial, quoiqu'elles admettent la précarité des ressources énergétiques à l' échelle nationale et mondiale. L' attitude conservatrice se distingue plus particulikrèment à partir d' ajustements limités reliés géneralement aux schémas de perceptions énergétiques et aux facteurs socio-économiques.  相似文献   

15.
There is a risk that the threat of nuclear war will be exaggerated in ways injurious to arms control and will deliver to the Soviet leadership the political returns it may be seeking. This undesirable outcome is the result of logical tricks we play on ourselves in trying to be very precise about factors like the accuracy of missiles. It is also the result of the peculiar assymmetry of the discussion of strategic matters, as all of the publicity work for Soviet weapons accomplishments is done by the press and governments of the West. Proposals for remedy would be to watch our own habits of logic, so that we do not persuade ourselves that our weapons capability or our political resolve are weak, and to force the Soviets to produce more information about their strategic capabilities.  相似文献   

16.
According to the 1970 census, the Soviet Union had 37,800 rural nonfarm places with a combined population of 6.1 million, or 5.8 percent of the rural population. The census data are believed to understate the number and population of nonfarm places because they assigned rural places to the nonfarm category purely on the basis of their generic designation. Many multifunctional nonfarm places and rural places that serve as administrative centers and have little relation to agriculture were not categorized as nonfarm in the census. Although many of the smaller nonfarm places are likely to be eliminated over time, others will continue to perform clearly defined functions in industry, construction, transportation, and services. The situation is illustrated with particular reference to Novosibirsk Oblast.  相似文献   

17.
古村落旅游开发的视觉影响与管理--以西递-宏村为例   总被引:19,自引:2,他引:19  
孙静  苏勤 《人文地理》2004,19(4):37-40
分析了古村落旅游资源的特点,在对皖南徽州古村落——西递、宏村的居民、游客的随机抽样问卷调查结果显示:古村落旅游资源存在的视觉污染严重。以调查结果为依据,分析了古村落视觉影响的现状,探寻其成因,并找出对策,提出视觉管理的原则及方法。  相似文献   

18.
This work investigates the decayed decoration of the ‘Vergine del Carmelo’ chapel, with a particular interest in the residual gildings. Samples of the finishing layers were examined by VIS‐UV optical microscopy and scanning electron microscopy coupled with EDX spectrometry, in order to evaluate the unusual degradation phenomena. Mineralogical composition of the stucco substrate was characterized by X‐ray diffraction (XRD) and FTIR spectroscopy. The results showed the unexpected presence of a thick layer of brass flakes, applied without any binder, used as a substitute for the damaged original gold leaf, and highlighting a very uncommon selective corrosion process of the brass.  相似文献   

19.
厦门主题公园面临的问题、原因与对策   总被引:2,自引:0,他引:2  
厦门主题公园运行的时间不长 ,但全国大多主题公园所面临的客流量少、重游率低等问题 ,在厦门已有突出的表现。文章剖析了厦门主题公园客流量少 ,重游率低的主客观原因 ,提出促进厦门主题公园发展 ,政府部门必须加大招商引资力度 ,加强宏观指导和行业管理 ;投资及经营管理者必须重新审定主题及规模 ,调整园区规划 ,完善和丰富景区旅游产品 ,加大宣传促销力度等对策及建议  相似文献   

20.
近年来,不少地方陆续有早期明刀、尖首刀出土。由于多属偶然发现,又多为罐装,一次出土数量不大,刀币出土之时也就成为流散之日,不无遗憾。为不使具有研究价值的材料销声匿迹,现将了解到的几次发现情况和有关实物简介如下,供学术界研究、参考。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号