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排序方式: 共有106条查询结果,搜索用时 109 毫秒
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Abstract: This paper compares the evolution of the dominant politico‐economic paradigm over the past 80 years in two ‘resource periphery’ nation states that have become ‘models’ of economic reform, New Zealand and Chile. Analysing the forces that have driven change, it traces the shared transition from a neoclassical model, through structuralist/Keynesian principles, and on to neoliberalism. The paper discusses whether the contemporary convergence around neostructural policy represents a paradigm shift or an adaptation of the neoliberal model designed to sustain free‐market principles in a form that is acceptable to electorates. The paper concludes that the broad commonalities in the transitions are remarkable and come about as a result of shared external shocks as well as similar historical insertions into the global political economy. Notwithstanding the parallels, the comparative approach reminds us of the contingent unfolding of economic paradigms across space, a point that counters arguments that assert that neoliberalism, and the globalisation to which it gives rise, create a homogenous global political economy. This comparative study is timely, as the two countries have recently signed a bilateral strategic trade partnership. This agreement indicates continued pursuit of neoliberal agendas in both countries rather than, as respective governments have heralded it, a move to foster South–South cooperation.  相似文献   
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Journal of Soils and Sediments - Soil organic carbon (SOC) dynamics are central to understanding the effects of environmental change on the carbon cycle of ecosystems. Vegetation and soil stable...  相似文献   
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The potential for gene flow between Camelina sativa, a promising edible and industrial oil crop in Canada, and its wild North American relatives C. alyssum, C. microcarpa and C. rumelica subsp. rumelica, was investigated. Sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was used to differentiate Camelina species and/or accession‐specific nucleotide markers and identify interspecific F1 hybrids. ITS analysis identified hybrids in progeny of C. alyssum × C. sativa, C. microcarpa accession 36010 × C. sativa and C. sativa × C. rumelica subsp. rumelica. Seed set on C. alyssum × C. sativa F1 and F2 progeny was similar to the parents; few seeds were produced on hybrid progeny of C. microcarpa accession 36010 × C. sativa and C. sativa × C. rumelica subsp. rumelica. The study provided evidence that should the species have sympatric distributions and overlapping flowering periods, gene flow between C. sativa and its wild North American relatives is possible and that it would most likely occur with C. alyssum given the high fertility of the F1 hybrids recovered.  相似文献   
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The Voyager 1 planetary radio astronomy experiment detected two distinct kinds of radio emissions from Saturn. The first, Saturn kilometric radiation, is strongly polarized, bursty, tightly correlated with Saturn's rotation, and exhibits complex dynamic spectral features somewhat reminiscent of those in Jupiter's radio emission. It appears in radio frequencies below about 1.2 megahertz. The second kind of radio emission, Saturn electrostatic discharge, is unpolarized, extremely impulsive, loosely correlated with Saturn's rotation, and very broadband, appearing throughout the observing range of the experiment (20.4 kilohertz to 40.2 megahertz). Its sources appear to lie in the planetary rings.  相似文献   
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Within distances to Uranus of about 6 x 10(6) kilometers (inbound) and 35 x 10(6) kilometers (outbound), the planetary radio astronomy experiment aboard Voyager 2 detected a wide variety of radio emissions. The emission was modulated in a period of 17.24 +/- 0.01 hours, which is identified as the rotation period of Uranus' magnetic field. Of the two poles where the axis of the off-center magnetic dipole (measured by the magnetometer experiment aboard Voyager 2) meets the planetary surface, the one closer to dipole center is now located on the nightside of the planet. The radio emission generally had maximum power and bandwidth when this pole was tipped toward the spacecraft. When the spacecraft entered the nightside hemisphere, which contains the stronger surface magnetic pole, the bandwidth increased dramatically and thereafter remained large. Dynamically evolving radio events of various kinds embedded in these emissions suggest a Uranian magnetosphere rich in magnetohydrodynamic phenomena.  相似文献   
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The Voyager 2 Planetary Radio Astronomy experiment to Jupiter has confirmed and extended to higher zenomagnetic latitudes results from the identical experiment carried by Voyager 1. The kilometric emissions discovered by Voyager 1 often extended to 1 megahertz or higher on Voyager 2 and often consisted of negatively or, less frequently, positively drifting narrowband bursts. On the basis of tentative identification of plasma wave emissions similar to those detected by Voyager 1, the plasma torus associated with Io appeared somewhat denser to Voyager 2 than it did to Voyager 1. We report here on quasiperiodic sinusoidal or impulsive bursts in the broadcast band range of wavelengths (800 to 1800 kilohertz). A Faraday effect appears at decametric frequencies, which probably results from propagation of the radiation near its sources on Jupiter. Finally, we discuss the occurrence of decametric emission in homologous arc families.  相似文献   
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