排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
2.
大地震发生后立即在断层带上进行钻探可以帮助我们获取更多的地震信息,尤其是可获得决定断层动态破裂的摩擦水平和强度,观测断层的愈合过程及可能触发余震的应力变化,并可获取控制破裂过程的重要的物理和化学属性。在2008年11月由国际大陆科学钻探项目(ICDP)和南加州地震中心(SCEC)联合在日本东京举办的为期3天的“震后快速钻探:历史、现状与未来”研讨会上, 相似文献
3.
4.
Strength and deformation behavior of the Shimanto accretionary complex across the Nobeoka thrust 下载免费PDF全文
A rapid reduction in sediment porosity from 60 to 70 % at seafloor to less than 10 % at several kilometers depth can play an important role in deformation and seismicity in the shallow portion of subduction zones. We conducted deformation experiments on rocks from an ancient accretionary complex, the Shimanto Belt, across the Nobeoka Thrust to understand the deformation behaviors of rocks along plate boundary faults at seismogenic depth. Our experimental results for phyllites in the hanging wall and shale‐tuff mélanges in the footwall of the Nobeoka Thrust indicate that the Shimanto Belt rocks fail brittlely accompanied by a stress drop at effective pressures < 80 MPa, whereas they exhibit strain hardening at higher effective pressures. The transition from brittle to ductile behavior in the shale–tuff mélanges lies on the same trend in effective stress–porosity space as that for clay‐rich and tuffaceous sediments subducting into the modern Nankai subduction zone. Both the absolute yield strength and the effective pressure at the brittle–ductile transition for the phyllosilicate‐rich materials are much lower than for sandstones. These results suggest that as the clay‐rich or tuffaceous sediments subduct and their porosities are reduced, their deformation behavior gradually transitions from ductile to brittle and their yield strength increases. Our results also suggest that samples of the ancient Shimanto accretionary prism can serve as an analog for underthrust rocks at seismogenic depth in the modern Nankai Trough. 相似文献
5.
6.
Xiaobei Liang Demian Chen Da Ruan Bingyong Tang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(4):415-423
The financial supply chain is increasingly recognized as an area offering significant potential for generating bottom-line
improvements and creating competitive advantage. Insurers’ appraisal is one of the basic decisions for a company, and the
choosing course has always many criterions. Considering the stability of the financial supply chain, the coordination evaluation
and fuzzy multi-objective evaluation model of insurers’ risk management are firstly studied in this paper by using large system
theory and methods. The corresponding coordination evaluation index model is then established to evaluate, forecast and control
the actuality and the future of risk coordination management, and to improve the durative development for a combination pension
model. The evaluation standards of numerous insurers are established to constitute a set of vectors. By presenting a dimensional
point to each insurer, the optimal or the worst insurer is decided. Finally, the distances of each insurer to the optimal
or the worst insurer on the basis of the Euclidean distance are counted, and the insurers’ ordering according to the value
of distances is sorted out. The financial supply chain and large system theory and methods are combined to contribute new
evaluation models that revise the deficiency of intrinsic model and improve the financial stability. 相似文献
7.
Kenneth J.Mitchell Rex A.Saffer Steve B.Howell Thomas M.Brown 《Monthly notices of the Royal Astronomical Society》1998,295(1):225-239
A new sample of 31 faint B and A0 stars is reported, 30 of which comprise a complete sample within the limits ( U − V )<0 and 10.0< B ≲18.0. The sample is based on low- and intermediate-resolution spectrophotometry of colour-excess objects selected in the US survey. Atmospheric parameters for the stars are derived through the use of synthetic colours, Balmer-line strengths, and model-atmosphere fitting. The atmospheric parameters and preliminary metallicity estimates indicate that most of the stars are distributed along the blue horizontal branch, with low metallicities ([Fe/H]∼−1.0) and with both the first and second Newell gaps present. However, nine of the B/A0 stars can be identified as candidate main-sequence stars, based on evidence of high metallicities ([Fe/H]∼0) and/or derived effective temperatures and surface gravities which place them close to the main-sequence relation. The completeness characteristics of the sample are discussed, and its surface density is compared to that of other recently isolated B-star samples. The sample exhibits a shallow integral number-count slope. This new sample will help provide increased statistical coverage of the B-star population in the Galactic halo through its relatively faint magnitude-completeness limits and its relatively red colour-completeness limit. 相似文献
8.
Rethinking geopolitics in an era of climate change 总被引:1,自引:0,他引:1
This article examines the disconnect between predictions about climate change and dominant geopolitical framings of the future. To begin, we introduce four popular geopolitical models of the world. We then show how climate change is a critical variable when considering the future of international politics. Focusing on the specific issues of water availability, agricultural productivity, coastal impacts, and shipping routes, we discuss the implications of predicted changes in the wake of climate change for the assumptions on which these scenarios are built. We show that work linking climate change and geopolitics has clear implications for the ways in which the future geopolitical (dis)order is conceptualized, and we argue that the failure to incorporate this work into geopolitical scenario-planning represents a significant limitation to their utility. We offer some direction for a re-conceptualization of the future based on a more dynamic and flexible approach to geopolitics that recognizes the disruptions posed by climatic and other environmental changes. 相似文献
9.
R. Oreiro F. Pérez Hernández M. Manteiga A. Ulla J.M. González Pérez M.R. Zapatero Osorio R. GarcÍa López J. MacDonald P. Thejll A. Ferriz-Mas R.A. Saffer V. Elkin 《Astrophysics and Space Science》2003,284(1):269-272
Hot subdwarf stars (hot sds) are blue subluminous objects. Only a few determinations areavailable to date regarding the study of such aspects as rotation,microturbulent velocities or the magnetic nature of these objects. Over26 sdBs are known to date to be multiperiodic rapid oscillators. Thisproject presents preliminary results of new observations and models of asample of pulsating and non-pulsating hot sds, includingconsiderations on mass loss and eventual magnetic properties. 相似文献
10.
Abstract The transformation of smectite‐group clay minerals to illite has garnered considerable interest as a potentially important process affecting both the mechanical and hydrologic behavior of subduction zones. Illitization can generate fluid overpressure by release of bound water, and the mineralogical change and associated cementation may increase intrinsic frictional strength while decreasing the sliding stability of faults. Released bound water also contributes to pore water freshening observed in boreholes at numerous margins. Here the authors combine data from Ocean Drilling Program drill sites along two transects at the Nankai subduction zone with numerical models of smectite transformation, to (i) quantify the distribution of smectite transformation and fluid production downdip of the trench; and (ii) evaluate its hydrologic and mechanical implications. High heat flow (ca 180 mW/m2) along the axis of the Kinan Seamount Chain (Muroto transect) initiates clay mineral transformation outboard of the trench, whereas lower heat flow (70–120 mW/m2) 100 km to the SW (Ashizuri transect) results in negligible presubduction diagenesis. As a result, considerably more bound fluid is subducted along the Ashizuri transect; simulated peak fluid sources down‐dip of the trench are considerably higher than for the Muroto transect (ca 1.2–1.3 × 10?14/s vs ca 6 × 10?15/s), and are shifted ca 10 km further from the trench. More generally, sensitivity analysis illustrates that heat flow, taper angle, incoming sediment thickness, and plate convergence rate all systematically affect reaction progress and the distribution of bound water release down‐dip of the trench. These shifts in the loci and volume of fluid release are important for constraining fluid flow pathways, and provide insight into the links between clay transformation and fault mechanics. 相似文献