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31.
The Palmottu hydrosystem is located in a granitic host rock in southern Finland. Along well‐defined pathways in the fractured crystalline rock, strontium isotopes are used to trace the degree of water–rock interaction (WRI) and mixing processes in groundwaters. The 87Sr/86Sr ratios range between 0.716910 and 0.735606 in the surface waters and between 0.719991 and 0.750787 in the groundwaters, but are between 0.720 and 0.735 in most of the samples. Moreover, the results show a lack of correlation between the water chemistries determining the classification into different water‐types (Na–Cl, Na–SO4, etc.) and the results of the strontium (Sr) contents and Sr isotopic ratios. From a WRI standpoint, this implies that the Sr behaviour is independent of the water chemistry; the occurrence of large 87Sr/86Sr variations is site specific and mainly dependent on the lithology. A model to determine the 87Sr/86Sr ratio of water after interaction with granite was developed. This model is based on the assumption that Sr was derived from three minerals: plagioclase, K‐feldspar and biotite. The results of the calculation indicate that around half of the water analysed within the Palmottu hydrosystem can be explained by the weathering of the granites. However, clearly lower 87Sr/86Sr are observed in waters when compared to the calculated 87Sr/86Sr and other sources of Sr, with low 87Sr/86Sr, rather than the calculated granite–water interaction, which may be suspected. When comparing the 87Sr/86Sr and ion ratios (Ca/Na, Mg/Na, Sr/Na, Cl/Na), the scattering of the data can be explained by the presence of four end‐members: a brine component (low 87Sr/86Sr and Ca/Na ratios…), a deep granitic component (high 87Sr/86Sr ratios and low Ca/Na ratios…), a subsurface component (intermediate 87Sr/86Sr ratios associated with high Ca/Na ratios…) and a surface end‐member:snow and river drainage (low 87Sr/86Sr and low Ca/Na ratios…). These extreme end‐members define a series of WRI‐mixing line within a rather complex hydrosystem.  相似文献   
32.
In the present paper, it is shown that in the Hergla area (eastern Tunisia), obsidian was present from the early to at least the late sixth millennium cal BC. The presence of cores indicates that obsidian knapping was at least partly carried out in situ. The origin of these obsidians was determined from their elemental composition, by comparison with those originating from western Mediterranean potential sources, including analyses of new samples from the nearby Pantelleria Island. All obsidians were measured following the same protocol, by particle induced X-ray emission or by scanning electron microscopy/energy dispersion spectrometry. All the Hergla obsidians were found to originate from the Balata dei Turchi sources of Pantelleria. A review of the present body of knowledge on eastern Maghreb suggests, in spite of the still very preliminary data available, that Pantelleria was almost its unique provider of obsidians from the Epipalaeolithic to and during the Neolithic. However, the relative importance of the two main Pantellerian sources of Balata dei Turchi and Lago di Venere as providers of obsidian to eastern Maghreb remains to be investigated.  相似文献   
33.
In this paper we evaluate the relative analytical capabilities of SEM-EDS, PIXE and EDXRF for characterizing archaeologically significant Anatolian obsidians on the basis of their elemental compositions. The study involves 54 geological samples from various sources, together with an archaeological case study involving 100 artifacts from Neolithic Çatalhöyük (central Anatolia). With each technique the artifacts formed two compositional groups that correlated with the East Göllü Da? and Nenezi Da? sources. The non-destructive capabilities of these methods are emphasized (albeit with certain analytical limitations in the case of SEM-EDS), suggesting important new techniques for Near Eastern obsidian provenance studies.  相似文献   
34.
保障性住房建设解决了大量城市低收入家庭的住房问题,但大多区位偏远、交通不便,远离城市就业中心,导致低收入人群的通勤成本上升,进而对其就业和收入产生影响。本研究以昆明市为样本城市,选取廉租房、公租房和经适房3类保障性住区,利用通勤距离、通勤时间、通勤方式、工作地点等指标,从居住-就业空间匹配角度,揭示保障性住区居民就业空间特征;并通过建立包含空间虚拟变量的多元回归方程,揭示了保障性住区居民就业空间特征对其收入的影响。  相似文献   
35.
Three projects on the theories of machines are presented: “mecanology” of the architect Jacques Laffite (1932) inspired by biological evolution; “mecanical analysis ” of Louis Couffignal, a specialist in computing machines (1938), which pre figures functional analysis, and the algebraic theory of machines by the mathematician Jacques Riguet (beginning of the 1950’s). During those years, the three men are members of the Circle of Cybernetic Studies. The article focuses on the dialogue between projects, the axes of unification and divergence, and the styles, strategies and postulates of these three candidates, for generalization converging toward the reference constituted by cybernetics.  相似文献   
36.
This article studies the role of white, black and mulatto women during the last two years of the Haitian War of Independence, also known as the Haitian Revolution (1802–04). It might be expected that women's contribution was limited in wartime, but this article concludes otherwise. Desirable women were sought as prizes symbolic of a man's status in colonial society, or actively used their appeal to obtain political favours. Women of colour contributed to the rebellion in the fields of logistics, espionage and even combat. They also experienced martyrdom when convicted of aiding the rebel army. White women, in turn, were considered such an integral part of the colonial order that the rebels, led by Toussaint Louverture and Jean‐Jacques Dessalines, targeted them, as well as other civilians, during the fighting, then proceeded to exterminate all surviving whites after the rebel victory.  相似文献   
37.
Situated along the southern fringe of the North Sea basin, northwest Belgium holds great potential for understanding hunter–gatherer responses to environmental change at the Pleistocene–Holocene transition. Recent intensive fieldwork has yielded valuable data on the palaeoenvironment, chronology, and hunter–gatherer mobility and land use in this region. At the Late Glacial/Early Holocene transition this region was comprised of a landscape of coversand ridges and lakes that flanked the northern part of the Scheldt river basin. This landscape was highly productive for hunter–gatherer populations. As the landscape developed in response to the increasing water table caused by the inundation of the North Sea populations responded by changing their forms of mobility and land use. These changes are indicated by the reduction in the number and density of sites, as well as their geographical settings, from the Late Glacial (Federmesser) and Early Mesolithic to the Middle-Final Mesolithic. Late Glacial/Early Mesolithic sites indicate much higher mobility comprised of rapid displacements of camps and re-occupation of the same coversand ridges over long time-spans. Middle/Late Mesolithic sites indicate a reduction in mobility, increasing focus on prolonged riverside settlement, and a more rigid organization of residential sites.  相似文献   
38.
39.
Many data sets collected for study areas consist of data values collected on a square lattice or for a set of pixels. Remotely sensed data provide perhaps the most common example. Frequently, we wish to know whether there are subregions of the study area that exhibit spatial clustering. In this article, we suggest how an approach for finding spatial clusters may be combined with the common practice of using 3‐by‐3 and 5‐by‐5 smoothing filters or kernels to construct two simple and easy‐to‐implement scan‐type tests. A simulation experiment shows that the power of these tests to find clusters compares favorably with an alternative test that is more complicated. The tests use simulated data, changes in a remotely sensed image for a study region in Texas, and data about wheat yields. Muchas bases de datos que se recopilan para una zona de estudio, consisten en valores recopilados en una retícula cuadrada o en un conjunto de pixeles. Los datos obtenidos por sensores remotos son quizá el ejemplo más común. Frecuentemente deseamos saber si existen subregiones de la zona de estudio que exhiban agrupamiento espacial. En este artículo, sugerimos cómo una aproximación para ubicar agrupamientos espaciales se puede combinar con la práctica común de usar filtros de suavizado (kernels) de 3‐por‐3 y 5‐por‐5 filtros, para construir dos test tipo scan, sencillos y fáciles de implementar. Un experimento de simulación demuestra que el poder de estas pruebas para ubicar agrupamientos, se compara favorablemente frente a otra prueba alternativa, que resulta más complicada. Las pruebas usan datos simulados, cambios en una imagen de satélite para un área de estudio en Texas, y con data acerca de los rendimientos de cultivos de trigo. 研究区收集的许多数据集是由基于方格网和像素采集的数据值组成的,遥感数据可能提供了最常见的范例。通常,我们希望了解研究区的子区域是否呈现空间集聚特征。本文提出了一种如何发现空间集聚的方法,可以与采用3*3和5*5平滑滤波或核函数的普通试验相结合,构造两个简单且易于操作的扫描试验。模拟实验结果显示,这些试验在寻找聚集特征的性能上优于更复杂的可替换性试验。文中所用的仿真模拟数据来源于德克萨斯州小麦产量的多时相遥感影像。  相似文献   
40.
Dreams and Discourses (1627) by Francisco de Quevedo is a Baroque satirical work composed by five dreamlike narrations that criticize the moral decadence of seventeenth-century Spanish society. Traditionally, it has been read as a conservative Catholic text that conveys an official view of truth and morality. This article attempts to question that reading by addressing the use of subversive strategies, such as wordplay and ambiguity. Through an analysis of the paratext, the narrative voices, and the satire of popular trades—e.g., bankers—the article sheds light on the text's self-erosion of established moral and epistemological values. It concludes that behind its apparent religious correctness, the work reflects on the fundamental opacity of language. Theoretically, Quevedo's satire is understood as a disseminatory artifact following Derrida in Dissemination.  相似文献   
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