95 research outputs found
National increment of the concept of sustainable development: experience of the EEU states
One of these strategies is called the concept of sustainable development. Currently, there are several variants for this concept. The version of the concept formulated in United Nations documents is the most prevailing. A feature of the documents adopted in the EEU member states on sustainable growth is their programmatic nature. The implementation of the provisions enshrined requires the adoption of separate regulatory legal acts. This also holds true for organ
Hidden scale invariance of metals
Density functional theory (DFT) calculations of 58 liquid elements at their
triple point show that most metals exhibit near proportionality between thermal
fluctuations between virial and potential-energy in the isochoric ensemble.
This demonstrates a general "hidden" scale invariance of metals making the
dense part of the thermodynamic phase diagram effectively one dimensional with
respect to structure and dynamics. DFT computed density scaling exponents,
related to the Gr{\"u}neisen parameter, are in good agreement with experimental
values for 16 elements where reliable data were available. Hidden scale
invariance is demonstrated in detail for magnesium by showing invariance of
structure and dynamics. Computed melting curves of period three metals follow
curves with invariance (isomorphs). The experimental structure factor of
magnesium is predicted by assuming scale invariant inverse power-law (IPL) pair
interactions. However, crystal packings of several transition metals (V, Cr,
Mn, Fe, Nb, Mo, Ta, W and Hg), most post-transition metals (Ga, In, Sn, and Tl)
and the metalloids Si and Ge cannot be explained by the IPL assumption. Thus,
hidden scale invariance can be present even when the IPL-approximation is
inadequate. The virial-energy correlation coefficient of iron and phosphorous
is shown to increase at elevated pressures. Finally, we discuss how scale
invariance explains the Gr{\"u}neisen equation of state and a number of
well-known empirical melting and freezing rules.Comment: 12 pages, 11 figure
Negative responses of highland pines to anthropogenic activities in inland Spain: a palaeoecological perspective
Palaeoecological evidence indicates that highland pines were dominant in extensive areas of the mountains of Central and Northern Iberia during the first half of the Holocene. However, following several millennia of anthropogenic pressure, their natural ranges are now severely reduced. Although pines have been frequently viewed as first-stage successional species responding positively to human disturbance, some recent palaeobotanical work has proposed fire disturbance and human deforestation as the main drivers of this vegetation turnover. To assess the strength of the evidence for this hypothesis and to identify other possible explanations for this scenario, we review the available information on past vegetation change in the mountains of northern inland Iberia. We have chosen data from several sites that offer good chronological control, including palynological records with microscopic charcoal data and sites with plant macro- and megafossil occurrence. We conclude that although the available long-term data are still fragmentary and that new methods are needed for a better understanding of the ecological history of Iberia, fire events and human activities (probably modulated by climate) have triggered the pine demise at different locations and different temporal scales. In addition, all palaeoxylological, palynological and charcoal results obtained so far are fully compatible with a rapid human-induced ecological change that could have caused a range contraction of highland pines in western Iberia
Accurate Hugoniots and sound velocities of bismuth under shock compression in the 38-100 GPa range
Pollen morphology of selected tundra plants from the high Arctic of Ny-Ålesund, Svalbard
Pollen and plant macrofossil analyses of radiocarbon dated mid-Holocene profiles from two subalpine lakes in the Rila Mountains, Bulgaria
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