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21.
Wayne S. Holland Jane S. Greaves Derek Ward-Thompson 《Astrophysics and Space Science》1995,224(1-2):487-488
We present recent JCMT polarimetric observations of the Oph A cloud core and the S106 HII region. We infer the magnetic field structure in these regions. 相似文献
22.
Segregation is a central concept in the debate on urban issues, both in scientific literature and in society in general. The
process of globalisation is particularly expected to increase polarisation and segregation in cities, resulting in the emergence
of ‘ghettos’ or – as they are called in the Netherlands – ‘income neighbourhoods’. This paper tries to judge the situation
in Dutch cities by studying changes over time; by looking at segregation within cities as well as between cities and the wider
metropolitan area; and by comparing socio-economic differences with socio-cultural and socio-demographic characteristics.
The analysis shows that the empirical facts are quite different from the ongoing debate. It establishes that socio-economic
segregation is more moderate than segregation with respect to the other two dimensions. Contrary to suggestions from the vernacular
debate, segregation within cities is scarcely increasing, but between cities and the surrounding area it is rising with respect
to all three dimensions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
23.
Geochemical characterisation and geophysical mapping of Landfill leachates: the Marozzo canal case study (NE Italy) 总被引:1,自引:0,他引:1
N.?Abu-ZeidEmail author G.?Bianchini G.?Santarato C.?Vaccaro 《Environmental Geology》2004,45(4):439-447
An integrated approach including geochemical analyses and geophysical investigations, aimed at characterizing the chemical composition of leachate and at highlighting the extent and magnitude of the plume in terms of spatial distribution is presented. The reason for the specific induced polarisation behaviour over landfills was not well understood. In this work we propose an explanation for this behaviour, which is being used to detect the presence of possible leaks and to track and delimit the pollution plume for several years.As a case study the example of an abandoned municipal solid waste landfill, located in Comacchio County, NE Italy, is presented, where the operative conditions for any resistivity monitoring method were to be excluded because of the high salinity of the phreatic aquifer. 相似文献
24.
M. D. Sharma 《Journal of Earth System Science》2005,114(4):411-419
Wave propagation is studied in a general anisotropic poroelastic solid saturated with a viscous fluid flowing through its
pores of anisotropic permeability. The extended version of Biot’s theory is used to derive a system of modified Christoffel
equations for the propagation of plane harmonic waves in such media. The non-trivial solution of this system is ensured by
a biquadratic equation whose roots represent the complex velocities of four attenuating quasi-waves in the medium. These complex
velocities define phase velocity and attenuation of each quasi-wave propagating along a given phase direction in three-dimensional
space. The solution itself defines the polarisations of the quasi-waves along with phase shift. The variations of polarisations
of quasi-waves with their phase direction, are computed for a realistic numerical model. 相似文献