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161.
Chris Dixon 《Singapore journal of tropical geography》2000,21(3):279-294
The debate over globalisation and the state has been sharpened by the emergence of such transitional economies as China and Vietnam. These states have become the subject of considerable attention, both in terms of the form that production is taking and the manner in which they interact with international capital. In both cases, interaction with international capital and the establishment of elements of the market economy have taken place under the auspices of highly centralised single party states. The resulting approach to the forces of economic globalisation has been both highly interventionist and, at times, extremely heavy-handed. As such, both countries may be seen as being seriously out of step with the advocates of liberalisation and economic globalisation. This paper seeks to further the understanding of the position of such states through an examination of Vietnam at two levels: first, through an overview of the distinctive and changing nature of the interaction and, second, through an examination of the nature and consequences of the differential treatment of labour and capital for foreign companies operating in Vietnam. 相似文献
162.
R. J. Dixon 《Geological Journal》1990,25(1):35-46
The Moel-y-Golfa Andesite is a discordant intrusive body of porphyritic pyroxene andesite, 1 km across and at least 200 m thick. Textural variation defines a central facies and a marginal facies, the latter displaying well-formed lobes, tubes, and pillows. The vertically stacked lobes, brecciated tubes, and elongate pillows of andesite intrude and locally enclose enclaves of altered host sediment and are cut by steeply dipping slide scars. The host sediments are locally strongly silicified and cut by numerous, anastomosed vertical and subvertical fissures. Fissures are filled by disrupted host sediment and fragments of brecciated andesite. The formation and filling of each fissure system was probably concomitant with the brecciation of an intrusive magma lobe. The complex relationship of igneous and sedimentary material indicates that the Moel-y-Golfa Andesite was emplaced into the host sediments whilst they were unconsolidated or only partly lithified. 相似文献
163.
Heat shock protein expression pattern (HSP70) in the hydrothermal vent mussel Bathymodiolus azoricus
We previously reported evidence of increased levels of DNA damage in the hydrothermal mussel Bathymodiolus azoricus, which suggested that the species was not fully resistant to the natural toxicity of its deep-sea vent environment. In the present study, HSP70 was used as a biomarker of sub-cellular stress. Differences in HSP70 expression pattern were observed between vent sites, typified by different depths/toxicity profiles, and between different mussel tissue types. A comparison of specimens collected by remote operated vehicle (ROV) and acoustically-operated cages showed that less stress (as indicated by changes in HSP70 levels) was induced by the faster cage recovery method. Therefore alternatives to ROV collection should be considered when planning experiments involving live deep sea organisms. Significantly, a positive correlation was found between the levels of DNA strand breakage, as measured using the Comet assay, and HSP70 expression pattern; evidence was also obtained for the constitutive expression of at least one HSP isoform which was located within the cell nucleus. 相似文献
164.
C. Rasmussen S. Brantley D. deB. Richter A. Blum J. Dixon A.F. White 《Earth and Planetary Science Letters》2011,301(3-4):521-530
Investigations to understand linkages among climate, erosion and weathering are central to quantifying landscape evolution. We approach these linkages through synthesis of regolith data for granitic terrain compiled with respect to climate, geochemistry, and denudation rates for low sloping upland profiles. Focusing on Na as a proxy for plagioclase weathering, we quantified regolith Na depletion, Na mass loss, and the relative partitioning of denudation to physical and chemical contributions. The depth and magnitude of regolith Na depletion increased continuously with increasing water availability, except for locations with mean annual temperature < 5 °C that exhibited little Na depletion, and locations with physical erosion rates < 20 g m? 2 yr? 1 that exhibited deep and complete regolith Na depletion. Surface Na depletion also tended to decrease with increasing physical erosion. Depth-integrated Na mass loss and regolith depth were both three orders of magnitude greater in the fully depleted, low erosion rate sites relative to other locations. These locations exhibited strong erosion-limitation of Na chemical weathering rates based on correlation of Na chemical weathering rate to total Na denudation. Sodium weathering rates in cool locations with positive annual water balance were strongly correlated to total Na denudation and precipitation, and exhibited an average apparent activation energy (Ea) of 69 kJ mol? 1 Na. The remaining water-limited locations exhibited kinetic limitation of Na weathering rates with an Ea of 136 kJ mol? 1 Na, roughly equivalent to the sum of laboratory measures of Ea and dissolution reaction enthalpy for albite. Water availability is suggested as the dominant factor limiting rate kinetics in the water-limited systems. Together, these data demonstrate marked transitions and nonlinearity in how climate and tectonics correlate to plagioclase chemical weathering and Na mass loss. 相似文献
165.
This paper is concerned with the fundamental controls affecting the quality of data derived from historical aerial photographs typically used in geomorphological studies. A short review is provided of error sources introduced into the photogrammetric workflow. Data‐sets from two case‐studies provided a variety of source data and hence a good opportunity to evaluate the influence of the quality of archival material on the accuracy of coordinated points. Based on the statistical weights assigned to the measurements, precision of the data was estimated a priori, while residuals of independent checkpoints provided an a posteriori measure of data accuracy. Systematic discrepancies between the two values indicated that the routinely used stochastic model was incorrect and overoptimistic. Optimized weighting factors appeared significantly larger than previously used (and accepted) values. A test of repeat measurements explained the large uncertainties associated with the use of natural objects for ground control. This showed that the random errors not only appeared to be much larger than values accepted for appropriately controlled and targeted photogrammetric networks, but also small undetected gross errors were induced through the ‘misidentification’ of points. It is suggested that the effects of such ‘misidentifications’ should be reflected in the stochastic model through selection of more realistic weighting factors of both image and ground measurements. Using the optimized weighting factors, the accuracy of derived data can now be more truly estimated, allowing the suitability of the imagery to be judged before purchase and processing. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
166.
Abstract Remotely sensed imagery from space-borne platforms is a valuable tool for illustrating the spatial scale and temporal changes associated with a variety of natural hazards. Imagery in numerous formats is freely available from US government websites. This article illustrates the use of such imagery as a pedagogic tool in a university-level Natural Hazards class. Illustrated examples include such hazards as volcanic eruptions, forest fires, dust storms, and hurricanes. 相似文献
167.
John C. Dixon 《自然地理学》2013,34(4):370-384
This paper discusses the use of soils as indicators of environmental change in the alpine and sub-alpine zones of the Colorado Rocky Mountains. Textural, miner-alogical, and chemical properties of soils developed on Quaternary glacial moraines are examined. A clear discontinuity in soil properties is observed between surface and subsurface horizons. Surface horizons are commonly finer grained and less strongly weathered than subsurface horizons. The soil-property discontinuity is interpreted to be a reflection of parent-material change. Surface horizons are interpreted to have developed in eolian sediments, while subsurface horizons have developed in glacial till. The duplex soils are believed to reflect alternating changes from cold moist climates and glacial advance to cold dry climates and loess deposition. [Key words: alpine soils, alpine weathering, alpine loess, climate change.] 相似文献
168.
Megan Dixon 《Urban geography》2013,34(3):353-375
Abstract The courtyard is a space that existed before, during, and now after the Soviet period in Russian urban history. Noting the change in the courtyard's formerly hegemonic position on daily trajectories illustrates both Harvey's and Lefebvre's suggestions for uncovering the way that spaces articulate social values. A particularly revealing case study occurs in the struggle over including courtyards in a Chinese developer's project for a new multi-use district outside St. Petersburg. A brief history of the courtyard in Soviet planning allows subsequent analysis of the ways in which the city administration, the Chinese design team, and Russian planners deployed the courtyard as a spatial code for social meaning in design discussions. Examining the change in function and conceptualization of the courtyard shows how different groups in post-Soviet Russia seek to retain or redeploy concepts of the “collective” as they attempt to remake St. Petersburg as a successful “world” city. 相似文献
169.
170.