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对采自冲绳海槽中部海底的浮岩样品和邻近陆地樱岛火山的安山岩样品进行了温度 (常温 - 15 0 0℃ )与压力 (常压 - 2 .4 GPa)实验 ,测得在较低温度 -压力条件下 (<1GPa,<80 0℃ )浮岩样品的纵波速度小于安山岩样品的纵波速度 ,在较高温度 -压力条件下 (>1GPa,>80 0℃ )二者的纵波速度接近一致 (5 .9km /s)。 1GPa/80 0℃是浮岩样品和安山岩样品的热动力相变点 ,推测该点的深度大于 18km。  相似文献   
2.
Determination of the Absolute Hydrogen Isotopic Ratio of V-SMOW and SLAP   总被引:1,自引:0,他引:1  
By mixing 1H2O and 2H2O, both with accurately known purity, samples were prepared with 2H/1H ratios close to those of the international isotopic water standards: V-SMOW and SLAP. A mass spectrometrical comparison of these calibration samples with the actual water standards revealed:
2H/1H of V-SMOW = (155.95 ± 0.08) × 10−6
2H/1H of SLAP = (89.12 ± 0.07) × 10−6
δ2HV-SMOW(SLAP) =−428.5 ± 0.5 %  相似文献   
3.
Better models are more effectively connected models   总被引:1,自引:0,他引:1       下载免费PDF全文
Water‐ and sediment‐transfer models are commonly used to explain or predict patterns in the landscape at scales different from those at which observations are available. These patterns are often the result of emergent properties that occur because processes of water and sediment transfer are connected in different ways. Recent advances in geomorphology suggest that it is important to consider, at a specific spatio‐temporal scale, the structural connectivity of system properties that control processes, and the functional connectivity resulting from the way those processes operate and evolve through time. We argue that a more careful consideration of how structural and functional connectivity are represented in models should lead to more robust models that are appropriate for the scale of application and provide results that can be upscaled. This approach is necessary because, notwithstanding the significant advances in computer power in recent years, many geomorphic models are still unable to represent the landscape in sufficient detail to allow all connectivity to emerge. It is important to go beyond the simple representation of structural connectivity elements and allow the dynamics of processes to be represented, for example by using a connectivity function. This commentary aims to show how a better representation of connectivity in models can be achieved, by considering the sorts of landscape features present, and whether these features can be represented explicitly in the model spatial structure, or must be represented implicitly at the subgrid scale. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   
4.
Enrichment dating procedure (GrN-9394) on a sample from the interstadial site Tåsjö, Ångermanland, Sweden, which is referred to the Jämtland Interstadial, has given the age 54,700±550 B.P. In the northwest European chronology this corresponds to late Odderade.  相似文献   
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