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1.
Wave propagation in anisotropic linear viscoelastic media: theory and simulated wavefields 总被引:6,自引:0,他引:6
J. M. Carcione 《Geophysical Journal International》1990,101(3):739-750
2.
Helmut Kerndorff Stephan Kühn Thomas Minden Dagmar Orlikowski Thomas Struppe 《Environmental Geology》2008,55(2):291-301
The aim of this research project is to identify, characterize and quantify natural attenuation (NA) processes in groundwater
affected by emissions of abandoned waste disposal sites in Berlin-Kladow/Gatow, Germany. It is part of the funding priority
called KORA established by the Federal Ministry for Education and Research (BMBF) to explore the extent to which NA can be
used for remedial purposes for varied forms of soil and groundwater contamination. Information on the emission behaviour of
individual parameters is generated on the basis of hydrogeochemical comparison of 20 years old and new data. Using groundwater-modelling
and CFC-analysis, information on the transport and retention of pollutants in groundwater is compiled. The microbial colonization
of contaminated aquifers is characterized by molecular biological methods [polymerase chain reaction (PCR) and denaturing
gradient gel electrophoresis (DGGE)] to differentiate between contaminated and not contaminated zones. 相似文献
3.
Memorial landscapes: analytic questions and metaphors 总被引:1,自引:0,他引:1
Over the past two decades, geographers have probed the intersection of collective memory and urban space. Their sustained
interest in the subject reflects an understanding of the social condition of commemoration and the important role that space
plays in the process and politics of collective memory. Along with other critical social scientists, geographers envision
these public symbols as part of larger cultural landscapes that reflect and legitimate the normative social order. A review
of the extant literature indicates that geographers scrutinize memorial landscapes through three conceptual lenses that may
be understood via the metaphors of ‘text,’ ‘arena,’ and ‘performance.’ These metaphors are in turn mobilized through a series
of analytic questions that serve to identify the interests served and denied by landscape ‘texts,’ the ‘arenas’ in which they
are produced, and the ways in which they are enacted via ‘performance.’ This article’s synopsis of the subfield’s predominant
metaphors and its attendant questions contributes to the ongoing cultural geographic project of articulating and implementing
methods for interpreting landscapes as open-ended symbolic systems.
相似文献
Derek H. AldermanEmail: |
4.
Historical space as narrative medium: on the configuration of spatial narratives of time at historical sites 总被引:1,自引:0,他引:1
This paper examines how narratives of history are organized spatially at historical sites and memorial spaces, especially
in urban settings and in places invested with a sense of collective memory. Much recent research has focused on landscape,
memory, and place and how relationships of political and social power influence the representation of historical events in
public spaces. Although the meaning of such sites may be hotly contested for long periods of time, we focus here on narrative
theory and the related, but unexplored, issue of how such historical stories are configured on the ground at actual historical
sites. We identify a number of narrative strategies which are frequently used to configure historical stories in space. Declamatory
strategies using markers presenting a snapshot of an event are common, but sequential and non-sequential linear strategies
are also used, as are thematic strategies that cross-cut space and time to present complex historical stories at various spatial
scales. Examples are drawn from a range of historical sites in North America, Europe and Israel. 相似文献
5.
刘连吉 《中国海洋大学学报(自然科学版)》1997,(3)
指出ISD单片语言器件的独特之处,是采用直接模拟存储技术,语音信号以其原本的模拟形式直接存入模拟量存储器中并长远保存。省去了传统的A/D和D/A数模转换机制,能高保真的将语音内容再生。这是一种高新录/放技术。另外,给出的ISD基本录/放电路十分简单易用。可方便地为微机系统、测控仪表电器和广播等设备所采用,使设备具有高效功能 相似文献
6.
In this note we investigated the effects of a thin visco-elastic mud layer on wave propagation. Within the framework of linear water-wave theory, analytical solutions are obtained for damping rate, dispersion relation between wave frequency and wave number, and velocity components in the water column and mud layer. The wave attenuation rate reaches a maximum value when the mud layer thickness is about the same as the mud boundary layer thickness. Heavier mud has a weaker effect on the wave damping. However, the wave attenuation rate does not always decrease as the elastic shear modulus increases. In the range of small values for elastic shear modulus, the wave attenuation can be amplified quite significantly. The current solutions are compared with experimental data with different wave conditions and mud properties. In general, good agreements are observed. 相似文献
7.
Frequency-selective attenuation of sound propagaion and reverberation in shallow waterTXFrequency-selectiveattenuationofsoundp... 相似文献
8.
海浪日最大波高序列的一种标度性质 总被引:1,自引:0,他引:1
应用重标度分析方法研究小麦岛海洋观测站1961-1980年二十年海浪日最大波高序列时发现,该序列并不是相互独立的,而是具有记忆性和持久性,详细的论证表明分式布朗运动模型是描述海浪日最大波高序列的一个较好的模型,同时,应用分式布朗运动模型我们找到了存在于海浪日最大波高序列中的一种标度性质-累积离差(t)的统计自仿射性。 相似文献
9.
10.
The purpose of this study is to validate and improve satellite-derived downward surface shortwave radiation (DSSR) over the northwestern Pacific Ocean using abundant in situ data. The DSSR derivation model used here assumes that the reduction of solar radiation by clouds is proportional to the product of satellite-measured albedo and a cloud attenuation coefficient. DSSR is calculated from Geostationary Meteorological Satellite-5/Visible Infrared Spin-Scan Radiometer data in 0.05° × 0.05° grids. The authors first compare the satellite DSSR derived with a cloud attenuation coefficient table determined in past research with in situ values. Although the hourly satellite DSSR agrees well with land in situ values in Japan, it has a bias of +13∼+34 W/m2 over the ocean and the bias is especially large in the low latitudes. The authors then improve the coefficient table using the ocean in situ data. Usage of the new table successfully reduces the bias of the satellite DSSR over the ocean. The cloud attenuation coefficient for low-albedo cases over the ocean needs to be larger in the low latitudes than past research has indicated. Daily and hourly DSSR can be evaluated from the satellite data with RMS errors of 11–14% and 30–33%, respectively, over a wide region of the ocean by this model. It is also shown that the cloud attenuation coefficient over land needs to be smaller than over the ocean because the effect of the radiation reflected by the land surface cannot be ignored. 相似文献