992 resultados para 7441-107


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This study investigates the landscape evolution and soil development in the loess area near Regensburg between approximately 6000-2000 yr BP (radiocarbon years), Eastern Bavaria. The focus is on the question how man and climate influenced landscape evolution and what their relative significance was. The theoretical background concerning the factors that controlled prehistoric soil erosion in Middle Europe is summarized with respect to rainfall intensity and distribution, pedogenesis, Pleistocene relief, and prehistoric farming. Colluvial deposits , flood loams, and soils were studied at ten different and representative sites that served as archives of their respective palaeoenvironments. Geomorphological, sedimentological, and pedological methods were applied. According to the findings presented here, there was a high asynchronity of landscape evolution in the investigation area, which was due to prehistoric land-use patterns. Prehistoric land use and settlement caused highly difIerenciated phases of morphodynamic activity and stability in time and space. These are documented at the single catenas ofeach site. In general, Pleistocene relief was substantially lowered. At the same time smaller landforms such as dells and minor asymmetric valleys filled up and strongly transformed. However, there were short phases at many sites, forming short lived linear erosion features ('Runsen'), resulting from exceptional rainfalls. These forms are results of single events without showing regional trends. Generally, the onset of the sedimentation of colluvial deposits took place much earlier (usually 3500 yr BP (radiocarbon) and younger) than the formation of flood loams. Thus, the deposition of flood loams in the Kleine Laaber river valley started mainly as a consequence of iron age farming only at around 2500 yr BP (radiocarbon). A cascade system explains the different ages of colluvial deposits and flood loams: as a result of prehistoric land use, dells and other minor Pleistocene landforms were filled with colluvial sediments. After the filling of these primary sediment traps , eroded material was transported into flood plains, thus forming flood loams. But at the moment we cannot quantify the extent ofprehistoric soil erosion in the investigation area. The three factors that controlled the prehistoric Iandscapc evolution in the Ioess area near Regensburg are as follows: 1. The transformation from a natural to a prehistoric cultural landscape was the most important factor: A landscape with stable relief was changed into a highly morphodynamic one with soil erosion as the dominant process of this change. 2. The sediment traps of the pre-anthropogenic relief determined where the material originated from soil erosion was deposited: either sedimentation took place on the slopes or the filled sediment traps of the slopes rendered flood loam formation possible. Climatic influence of any importance can only be documented as the result of land use in connection with singular and/or statistic events of heavy rainfalls. Without human impact, no significant change in the Holocene landscape would have been possible.

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Resumen: El salmo 106 (107) es una confesión de la misericordia de Dios que hace desvanecer las necesidades y angustias de quien clama a Él en distintas instancias de su camino de purificación y perfección. A la vez que confiesa, exhorta a la confesión. Esta confesión está estrechamente unida a la confianza y al abandono en Dios a las que, a su vez, se dirige dicha purificación. En la traducción jerónima iuxta Hebraeos hay marcas lingüísticas que indican el sentido de esta confesión, especialmente mediante la estructura confiteor + dativo.

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Contenido: Espíritu y cultura / Octavio N. Derisi – Estructura y sentido de la filosofía de la religión / Agustín Basave – El “Curso de Lógica” de Francisco Sebastiani (1791) / Celina A. Lértora Mendoza – Notas y comentarios -- Bibliografía

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There is, in nature, as well as in the aquarium, a parasitic disease known as 'mousse' and which attacks predominantly fish. It is caused by Phycomycete fungi, genus Saprolegnia. The fungus causes external lesions and covers the fish with a thick white layer from whence comes the name 'mousse', commonly attributed to the disease, for which the scientific name is Saprolegnia. This article provides an overview of Saprolegnia infections on fish in nature and aquaria and then discusses symptomology of Saprolegnia in the mirror caro and t roach in more detail.

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The mean-lifetimes, τ, of various medium-spin excited states in Pd103 and Cd106,107 have been deduced using the Recoil Distance Doppler Shift technique and the Differential Decay Curve Method. In Cd106, the mean-lifetimes of the Iπ=12+ state at Ex=5418 keV and the Iπ=11- state at Ex=4324 keV have been deduced as 11.4(17)ps and 8.2(7)ps, respectively. The associated β2 deformation within the axially-symmetric deformed rotor model for these states are 0.14(1) and 0.14(1), respectively. The β2 deformation of 0.14(1) for the Iπ=12+ state in Cd106 compares with a predicted β2 value from total Routhian surface (TRS) calculations of 0.17. In addition, the mean-lifetimes of the yrast Iπ=152- states in Pd103 (at Ex=1262 keV) and Cd107 (at Ex=1360 keV) have been deduced to be 31.2(44)ps and 31.4(17)ps, respectively, corresponding to β2 values of 0.16(1) and 0.12(1) assuming axial symmetry. Agreement with TRS calculations are good for Pd103 but deviate for that predicted for Cd107. © 2007 The American Physical Society.

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主要介绍了合成和鉴别107号元素的新同位素265Bh的实验装置、实验方法以及实验结果.目标核265Bh是由能量为135MeV的26Mg离子轰击243Am靶,通过融合蒸发反应而产生.反应产物首先由He jet系统传输到装有数个探测器对的转轮收集测量系统,然后依靠母子核遗传关系通过观察新同位素和它们已知子核261Db和257Lr之间的α衰变的关联,来实现对新核素的鉴别.实验测得265Bh的α衰变能量为(9.24±0.05)MeV, 半衰期为0.94+0.70-0.31s.从该实验得出的265Bh的α衰变能量和半寿命能够与理论预言一致.

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利用兰州重离子加速器提供的26Mg离子束轰击243Am靶, 产生了新同位素265Bh. 实验中用氦喷技术对产物进行传输, 并用一套具有数对探测器组的转轮收集探测系统对产物进行收集和测量. 通过观测265Bh与它的衰变子核261Db及257Lr之间的α衰变的关联, 实现了对新核素的鉴别. 实验测得265Bh的α衰变能量为(9. 24±0. 05)MeV, 半衰期为 0. 94+0. 70 0. 31 s.

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在兰州的重离子加速器上用 2 6Mg离子束轰击 2 43 Am靶 ,产生了新同位素 2 65Bh .通过观测新同位素 2 65Bh和它的已知子核 2 61Db和 2 57Lr之间的α衰变的关联 ,实现了对新核素的鉴别 .实验中使用了一套新建立的具有数个探测器对的转轮收集探测系统 .将该系统用于特殊的母 -子核搜索模式 ,从而大大减少了本底 .共测得了 8个 2 65Bh的α衰变关联事件 ;同时 4个已知核 2 64Bh的衰变关联事件也被鉴别出来 .实验测得 2 65Bh的α衰变能量为 (9.2 4± 0 .0 5 )MeV ,半衰期为 0 .94 + 0 .70-0 .3 1s .