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1.
2.
By defining local Moran's Ii as a ratio of quadratic forms and making use of its overall additivity to match global Moran's I, we can identify spatial objects with a strong impact on global Moran's I. First, we concentrate on the spatial properties of local Moran's Ii expressed by the local linkage degree. Depending on whether we use the W- or C-coding of the spatial connectivity matrix, the variance of local Moran's Ii for a small local linkage degree will be either large or small. Note that spatial objects associated with a local Moran's Ii with a large variance affect the global statistic much more than spatial objects associated with a local Moran's Ii with a small variance. Counterintuitively, global Moran's I defined in the W-coding is most influenced by spatial objects with a small number of spatial neighbors. In contrast, spatial objects with a large number of spatial neighbors exert more impact on global Moran's I setup in the C-coding. Second, we investigate the impact of the empirical data on local Moran's Ii and show that local Moran's Ii will only be significant for extreme absolute residuals at and around the reference location. Clusters of average regression residuals cannot be detected by local Moran's Ii. Consequently, spatial cliques of extreme residuals contribute more to significance tests on global autocorrelation.  相似文献   

3.
The Analysis of Spatial Association by Use of Distance Statistics   总被引:20,自引:0,他引:20  
Introduced in this paper is a family of statistics, G, that can be used as a measure of spatial association in a number of circumstances. The basic statistic is derived, its properties are identified, and its advantages explained. Several of the G statistics make it possible to evaluate the spatial association of a variable within a specified distance of a single point. A comparison is made between a general G statistic and Moran's I for similar hypothetical and empirical conditions. The empirical work includes studies of sudden infant death syndrome by county in North Carolina and dwelling unit prices in metropolitan San Diego by zip-code districts. Results indicate that G statistics should be used in conjunction with I in order to identify characteristics of patterns not revealed by the I statistic alone and, specifically, the Gi and Gi* statistics enable us to detect local “pockets” of dependence that may not show up when using global statistics.  相似文献   

4.
The development of Chinese ceramics culminated during the Song dynasty. At this time, exquisite celadon works emerged, such as Ru Guan celadon and Southern Song dynasty official kiln celadon, which exhibited the glory of their era. Since the excavation of Zhanggongxiang kiln celadon in Ruzhou city, Henan province, China, it has been attracting widespread scholarly attention at home and abroad. Most scholars have suggested that Zhanggongxiang is the official kiln of the Northern Song dynasty. In this paper, taking the celadon unearthed from the Zhanggongxiang kiln as a sample, the combination of laser Raman spectrum and thermal expansion methods is used to study the inheritance relationship between Zhanggongxiang celadon and Ru Guan celadon in the firing process. Meanwhile, the rationality of using Raman Ip value to evaluate the firing temperature of ceramics is reviewed. The main conclusions are as follows. First, the firing temperature of Zhanggongxiang celadon with various glaze colours is quite different, whereas the firing temperature of the same glaze colour is similar, thereby inheriting the firing technology of Ru Guan porcelain. Second, the Ip value of glaze cannot evaluate the firing temperature of porcelain with similar firing temperature. The Ip value corresponds to a range, within which it does not fully conform to the rule that the larger the Ip value, the higher the firing temperature. The Ip value is also associated with the formulation in addition to firing temperature. It is applicable to evaluating porcelains with a similar formulation but a large temperature difference.  相似文献   

5.
Twenty‐six tesserae (red, orange, yellow, light amber, green, blue and white) from the balneum of the villa at Faragola (Ascoli Satriano, Foggia) have been examined by colorimetry, ICP–MS, ICP–OES and SEM–EDS. Different types of calcareous sands have been used as the source of silica (network former), also providing the stabilizing agent. A natron‐type soda source served as the network modifier; however, the use of a sodium‐rich plant ash and the recycling process have been hypothesized for the production of two tesserae (FT 1 red and FT 3 orange). The colouring and opacifying agents were Cu oxide (cuprite, orange), metallic copper (red), Pb antimonates (yellow), Ca antimonates (white), a mixture of copper (Cu2+) and Pb antimonates (green), a mixture of cobalt (Co2+) or copper (Cu2+) and Ca antimonates (blue). The light amber tesserae should owe their colour to iron (Fe3+) alone or associated with sulphide (S2?) and Ca antimonates. It is likely that the Faragola tesserae were locally produced in a secondary glass workshop.  相似文献   

6.
This paper reports the δ13C and δ15N values of bone collagen, muscle and skin from several late prehistoric–early colonial (AD 1490–1640) mummies from Perú's Ayacucho Valley. The mean of the δ13C and δ15N values of bone collagen are −11.5 ± 1.4 and 11.1 ± 0.7‰, respectively. The mean of the δ13C values for Vinchos skin is −11.8 ± 1.2‰ and the mean of δ15N values is 13.2 ± 0.5‰. The samples of muscle tissue have a δ13C mean of −11.9 ± 0.9‰ and a δ15N mean of 12.7 ± 0.3‰. The data from bone collagen indicate maize was the basis of the region's subsistence economy. A significant correlation between δ13C and δ15N values of bone collagen (R2 = 0.75) is consistent with the preferential fertilization of maize with composted manure. Both skin and muscle samples are consistently enriched in δ15N relative to paired samples of bone (2.1 ± 0.5 and 1.6 ± 0.7‰, respectively), possibly as a result of short term physiological stress or differential decomposition.  相似文献   

7.
N. ABRAHAMSEN 《Archaeometry》1973,15(2):267-274
Fired bricks are used in archaeomagnetic work to determine the Inclination I of the earth's magnetic field at the time of firing. However, in addition to the usual mean error of between ± 1/2° and ± 2° due mainly to inexact levelling of the bricks during the firing, there is a systematic error in the measured mean value of the Inclination that may amount to 2° or 3° at high magnetic latitudes (I? 80°), while at lower magnetic latitudes (I< 60°) it is usually less than 1/2°. A method of correction based on the measured statistical spread of the bricks is suggested.  相似文献   

8.
Mormonism's growth from its 1830 inception to its 2005 near twelve million world membership, has not only initiated a debate over whether, perhaps, it is likely to become the next world‐religion after Islam, 1 1 Stark, Rodney , “The Rise of a New World Faith,” Review of Religious Research 26 (1984 ): 18 – 27 .
but has, in recent decades, also witnessed the publication of numerous books that help foster an interest in what is already becoming a distinctive field of study. Though none of the four books reviewed here constitutes an introductory overview, 2 2 For which see, Thomas O'Dea, The Mormons (Chicago: University of Chicago Press, 1957); Jan Shipps, The Story of a New Religious Tradition (Urbana and Chicago: University of Illinois Press, 1985); Douglas J. Davies, Introduction to Mormonism (Cambridge: Cambridge University Press, 2003).
each introduces a set of major issues within contemporary Mormon studies and engages, respectively, with faith‐related attitudes to historical material, the Book of Mormon, the changing status of black males in the church, and Freemasonry's impact on Mormonism's origin.  相似文献   

9.
The POGO electrojet data have been analysed for the winter and summer solstitial seasons of the two years, 1968 and 1969, respectively. Our analysis yielded a very large number of values (about 432), each of the electrojet half width, w, its peak current intensity, J0, and its total eastward current, I+, at 0900–1400 LT in December, and at 1000–1500 LT in June solstitial seasons, respectively. The all-longitude daytime values of the parameters are 246 ± 48 km for w,216 ± 60 A km−1 for J0, and (58 ± 8) × 103A for I+, in December of 1968 and 218 ± 19 km for w, 187 ± 20 A km−1 for J0, and (45 ± 3) × 103 A for I+, in June of 1969, respectively. We therefore present a diurnal study covering the entire Earth, in which for the first time, morning data earlier than 1000 LT are incorporated in the analysis. This has enabled us to chart a clearer picture of the temporal variations of electrojet parameters at two different solstices. This shows that all of the three parameters vary substantially with local time, in such a manner that J0 and I+ attain maximal values around local noon, while w is a minimum then, and therefore confirms the finding of Agu and Onwumechili.  相似文献   

10.
Eighty sherds from nine different kiln sites representing a wide geographic distribution and a long time span of Korean celadon culture are analysed for macroscopic and compositional characteristics. Additionally chemical and mineral compositions of six unglazed sherds are compared with those of some modern raw materials. Unusually high values of alumina in the earliest Kangjin pieces of the middle ninth and early tenth century (I1) could represent a significant technological innovation at the end of this period at this most important celadon production centre. Similarity in chemical and mineral compositions between unglazed sherds and some raw materials such as Kangjin clay and pottery stone show the possibility that many of the celadons were made from these types of raw materials as found in nature without additives and only after mechanical refining.  相似文献   

11.
In order to interpret strontium and oxygen isotope values in Neolithic human skeletons analysed previously, we begin to map the biologically available strontium, carbon and oxygen isotopic signatures of prehistoric southern Germany by analysing tooth enamel of pigs from archaeological sites distributed around the region. The mapping shows a marked upland–lowland difference in biologically available 87 Sr/ 86 Sr values, ranging between 0.7086 and 0.7103 in the sedimentary lowlands, and from 0.710 to as high as 0.722 in the crystalline uplands of the Odenwald, the Black Forest and the Bavarian Forest. In addition, carbon isotopes in the carbonate fraction of pig enamel were generally about 1–2 more enriched in 13 C in the uplands. Despite the expected depletion of 18 O with altitude, oxygen isotopes in pig enamel showed little correlation with site altitude, although for pig samples not older than the Iron Age there was some geographical correlation withδ18O patterns in modern precipitation.  相似文献   

12.
Stable carbon (δ13C) and nitrogen (δ15N) isotope ratios are commonly used to reconstruct palaeodiets and palaeoenvironments. The method is based on our knowledge of isotopic patterns in plants, which are subject to taxonomic and environmental variability. While previous researchers have addressed isotopic variability amongst plants, no studies have looked extensively at a broad suite of taxa over multiple temporal scales from within the savanna biome so as to provide baseline data for palaeodietary and palaeoenvironmental studies. Here we document variations in the isotopic compositions of plants collected over two years from the Kruger National Park, South Africa, with respect to species and anatomical differences, and the influences of geological substrate and spatio-temporal shifts in climate. Results show that environmentally-induced carbon isotopic variations in plants within this region are generally smaller than 2‰, which is lower than what has been previously reported for plants compared across multiple habitat-types. These data suggest that δ13C differences of 2‰ or more (or 1‰ if the diet is predominantly C4) between animals from a given area reliably indicate real dietary differences. Plant δ15N values vary greatly between different microhabitats (by up to 4‰), responding to a range of environmental influences that may, in turn, significantly influence variation in animal δ15N values.  相似文献   

13.
As is widely recognised, fossil florules are difficult to correlate because they appear to have been more controlled by environmental and ecological factors than uniform changes which reflect the passage of geological time. Here I present a worked example of a generally applicable approach to this problem in dating and mapping fossil plant associations.

Floral associations are best described and named by the classical methods of phytosociology. The three dimensional shape of an association in rocks and its palaeoecology can then be critically assessed. For example, during Middle Triassic time the following plant associations would have been encountered on a traverse from the coast to several hundred kilometres inland from the Pacific margin of Gondwanaland: Pachydermophylletum (mangrove scrub), Linguifolietum (coastal swamp woodland), Dicroidietum odontopteroidium (floodplain forest), Phoenicopsetum (levee bank scrub), Dicroidietum odontopteroidium xylopterosum (xerophytic woodland) and Johnstonietum (mallee-like woodland).

The fourth dimension of fossil plant associations (time) is best assessed from the evolution of a prominent group of plants. In conjunction with the ranges of other plant megafossils, evolutionary changes can be used to define Oppel-zones. For the Late Permian to Early Jurassic of eastern Australasia, I have used the evolution of Dicroidium and leaves of related pteridosperm plants together with other species of restricted stratigraphic range or prominent in the definition of the fossil plant associations. From this evidence four Oppel-zones can be recognised. ‘Thinnfeldia’ callipteroides Oppel-zone (Chhidruan to Smithian, 250–230 × 106 years), Dicroidium zuberi Oppel-zone (Smithian to Middle Anisian, 230–220 × 106 years), D. odontopteroides Oppel-zone (Late Anisian to Ladinian, 220–210 × 106 years) and Yabeiella Oppel-zone (Carnian to Rhaetian, 210–200 × 106 years.

In a complete revision of the pteridosperm form-genera Dicroidium, Johnstonia and Xylopteris, a large number of new combinations and the following new taxa are proposed; Dicroidium gouldii sp. nov., D. odontopteroides var. argenteum var. nov., D. odontopteroides var. moltenense var. nov., D. radiatum sp. nov., D. townrovii sp. nov. and Johnstonia coriacea var. obesa var. nov.  相似文献   

14.
Analyses at the Cu–K, Fe–K and Mn–K edge were performed to study the green, marbled (green and yellow), blue and blackish (deep greyish olive green) glass slabs decorating three sectilia panels from the archaeological site of Faragola. Results indicate that all slabs were made by mixing siliceous sand with natron, sometimes probably mixed with small percentages of plant ash. Cu2+ and Pb antimonates should be responsible for the opaque green colours. The dark green and yellow portions of the marbled slabs are respectively comparable to the slabs comprising only one of these colours. Cu2+ together with Ca antimonates probably produced light blue slabs, whereas cobalt was used to produce dark blue slabs. We consider it possible that the abundance ratio of Fe2+/Fe3+ and the complex Fe3+S2? would have an effect on the blackish slabs. The contribution of Mn cannot be ascertained even if it could have played a role in darkening glass colour. The comparison between the chemical composition of Faragola samples and several glass reference groups provided no conclusive evidence of provenance; whereas, the presence of a secondary local workshop can be hypothesized.  相似文献   

15.
An analysis of the POGO satellites observations of the magnetic field of the equatorial electroject for the September equinoctial months of the years 1967, 1968 and 1969, provided about 500 values each of the electrojet half-width w, its peak current intensity J0, its total eastward current I+ at 11, 12, 13, 14 and 15 h LT. The all-sector daytime average values of the parameters for the three years are 232 ± 47 A km−1 for J0, 234 ± 6 km for w and (55± 8)×103 A for I+.This first coverage of all sectors of the globe gives the first study of the diurnal variation of the total current and shows that all the three parameters vary substantially with local time; that w has minimal values around local noon; that J0 has a pronounced peak around local noon as may be expected from the diurnal variation of H; and that I+ has a broad maximum around 11 h and 12 h LT.  相似文献   

16.
A fossil mandible and incisor of the diprotodontid marsupial Palorchestes azeal Owen is reported from a new locality at Pulbeena, near Smithon, in northwestern Tasmania. The fossils occurred with a piece of wood which has a 14C age of 54,200-4,500 +11,000 B.P. Both fossils and wood were deposited contemporaneously in shallow-lake shell marls and swamp peat deposits of late Quaternary age. Pollen analysis indicates that this P. azael inhabited a Eucalyptus woodland.  相似文献   

17.
The petrography as well as the major and trace element compositions of the Selinunte grinding stones, made of grey vesicular lava, were analysed. By comparison with geochemical data from volcanic rocks in the Mediterranean, we were able to determine that only a minor number of the tools were extracted from the nearest volcanics of Mount Etna and the Hyblean Mountains, while the majority of the grinding stones were most probably imported from the Aeolian Islands, although an origin from the Aegean cannot be excluded entirely. The results are important in order to scrutinize trading connections, especially for the earlier times of settlement during the sixth century bc .  相似文献   

18.
Here, we present δ13C and δ15N results for the dietary reconstruction of nomadic pastoralists from the Iron Age (ca. 1000 bc –8 ad ) site of Heigouliang. The human (n = 27) δ13C values range from −19.6‰ to −17.0‰ with a mean value of −18.5 ± 0.5‰, and the δ15N results range from 11.5‰ to 13.8‰ with a mean value of 12.4 ± 0.6‰. The results indicated that animals, like sheep, were part of the predominately C3 terrestrial diet, but two individuals have values greater than −18‰ that is indicative of some input of C4 foods in their diets. Because of a lack of faunal samples and to supply complementary information concerning plant consumption, teeth from four individuals were analysed for dental calculus microfossils. Starch grains were found to correspond to Triticeae and Poaceae, possibly including wheat (Triticum aestivum), barley (Hordeum vulgare), highland barley (H. vulgare L var. nudum), foxtail millet (Setaria italica) and/or common millet (Panicum miliaceum). At the population level, no dietary differences were detected between burial owners and sacrificial victims, but variations were found when specific tombs were analysed. In particular, individuals with bone trauma associated with armed conflict also had distinct isotopic signatures possibly suggesting that some of the sacrificial victims could have been captured warriors that were sacrificed for the burial owners. While limited, the results are some of the first from an Iron Age population from Xinjiang and contribute to our understanding of the dietary patterns of this region. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

19.
Most researchers in the Proterozoic eastern Mt Isa Block, NW Queensland, Australia, favour magmatic fluid and salt sources for sodic‐(calcic) alteration and iron oxide–copper–gold mineralization. Here we compare spatial, mineralogic and stable isotope data from regional alteration assemblages with magmatic and magmatic‐hydrothermal interface rocks in order to track chemical and isotopic variations in fluid composition away from inferred fluid sources. Tightly clustered δ18O values for magnetite, quartz, feldspar and actinolite for igneous‐hosted samples reflect high temperature equilibration in the magmatic‐hydrothermal environment. In contrast, these minerals record predominantly higher δ18O values in regional alteration and Cu–Au mineralization. This dichotomy reflects partial equilibration with isotopically heavier wallrocks and slightly lower temperatures. Increases in Si concentrations of metasomatic amphiboles relative to igneous amphiboles in part reflect cooling of metasomatic fluids away from igneous rocks. Variations in XMg for metasomatic amphiboles indicate local wallrock controls on amphibole chemistry, while variations in XCl/XOH ratios for amphiboles (at constant XMg) indicate variable aH2O/aHCl ratios for metasomatic fluids. Biotite geochemistry also reflects cooling and both increases and decreases in aH2O/aHCl for fluids away from plutonic rocks. Decreased aH2O/aHCl ratios for metasomatic fluids reflect in part scavenging of chlorine out of meta‐evaporite sequences, although this process requires already saline fluids. Local increases in aH2O/aHCl ratios, as well as local decreases in δ18O values for some minerals (most notably haematite and epithermal‐textured quartz), may indicate ingress of low salinity, low δ18O fluids of possible meteoric origin late in the hydrothermal history of the region. Taken together, our observations are most consistent with predominantly magmatic sources for metasomatic fluids in the eastern Mt Isa Block, but record chemical and isotopic variations along fluid flow paths that may be important in explaining some of the diversity in alteration and mineralization styles in the district.  相似文献   

20.
Archaeological and zooarchaeological data indicate that camelid pastoralism was a subsistence and economic mainstay of Middle Horizon and more recent cultures in the Osmore region of southern Peru. However, it is not known whether camelids were primarily herded in highland puna pastures or near lower elevation sites in the middle valley or along the coast. This research examines the elevation of archaeological camelid herding in the Osmore Valley using stable isotope analysis. Stable carbon (δ13C) and nitrogen (δ15N) isotope ratios were measured on 28 archaeological camelid bone samples from the Middle Horizon sites of Cerro Baúl and Cerro Mejía, the Late Intermediate site of Yaral and the late pre‐Hispanic to Colonial period site of Torata Alta. Twenty‐three archaeological camelids have δ13C and δ15N values similar to five modern camelids maintained in highland puna pastures. In contrast, three camelids from the high status Wari site of Cerro Baúl, and two from Yaral have unexpectedly high δ13C and/or δ15N values outside the expected range for camelids pastured in highland puna habitats. The results may be explained by differences in foddering practices, altitudinal herding range or climatic conditions. Strontium isotope ratios (87Sr/86Sr) were also assessed to infer pasture elevation using the camelid remains from Cerro Baúl (n = 11). One individual in this sub‐sample exhibits a non‐local 87Sr/86Sr value indicative of an origin in the highland puna region east or south of Lake Titicaca. It was not possible to further distinguish between camelids herded in lower to middle elevation habitats outside the Lake Titicaca basin using 87Sr/86Sr values. This study suggests that multiple isotope proxies may be used to identify animals primarily pastured in lowland coastal versus highland puna (> 4000 masl (meters above sea level)) habitats, but are less useful at distinguishing between animals pastured in lower to middle elevation settings. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

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