4,119 research outputs found
INTERNATIONAL TRADE POLICY: CHALLENGES AND OPPORTUNITIES FOR U.S. AGRICULTURE
International Relations/Trade,
Mango growing in Western Australia
This bulletin covers mango growing in Western Australia in Kununurra, Carnarvon, Kimberly, Gingin, Perth regions. Details include climate requirements, soils, propagation, planting, spacing, weed control, nutrition, pests, diseases and disorders, pruning, harvesting and packing, ripening and storage, and processing.https://researchlibrary.agric.wa.gov.au/bulletins/1003/thumbnail.jp
The quenching of compressible edge states around antidots
We provide a systematic quantitative description of the edge state structure
around a quantum antidot in the integer quantum Hall regime. The calculations
for spinless electrons within the Hartree approximation reveal that the widely
used Chklovskii et al. electrostatic description greatly overestimates the
widths of the compressible strips; the difference between these approaches
diminishes as the size of the antidot increases. By including spin effects
within density functional theory in the local spin-density approximation, we
demonstrate that the exchange interaction can suppress the formation of
compressible strips and lead to a spatial separation between the spin-up and
spin-down states. As the magnetic field increases, the outermost compressible
strip, related to spin-down states starts to form. However, in striking
contrast to quantum wires, the innermost compressible strip (due to spin-up
states) never develops for antidots.Comment: submitted to Phys. Rev. Let
National and Regional Impacts of U.S. Agricultural Exports
International Trade, Output, Employment, Exports, International Relations/Trade, Q10, Q11, Q13, Q17,
Management of soil organic matter and gypsum for sustainable production in the Carnarvon horticultural district of Western Australia
Soil quality is critically important for the long-term production of high quality and high yielding fruit and vegetable crops in the Carnarvon horticultural district of Western Australia. A stable soil structure is essential for good soil quality
Exchange and correlation near the nucleus in density functional theory
The near nucleus behavior of the exchange-correlation potential in Hohenberg-Kohn-Sham density functional theory is investigated. It is
shown that near the nucleus the linear term of of the spherically
averaged exchange-correlation potential is nonzero, and that
it arises purely from the difference between the kinetic energy density at the
nucleus of the interacting system and the noninteracting Kohn-Sham system. An
analytical expression for the linear term is derived. Similar results for the
exchange and correlation potentials are also
obtained separately. It is further pointed out that the linear term in
arising mainly from is rather small, and
therefore has a nearly quadratic structure near the nucleus.
Implications of the results for the construction of the Kohn-Sham system are
discussed with examples.Comment: 10 page
Sophisticated Inference.
Active inference offers a first principle account of sentient behavior, from which special and important cases-for example, reinforcement learning, active learning, Bayes optimal inference, Bayes optimal design-can be derived. Active inference finesses the exploitation-exploration dilemma in relation to prior preferences by placing information gain on the same footing as reward or value. In brief, active inference replaces value functions with functionals of (Bayesian) beliefs, in the form of an expected (variational) free energy. In this letter, we consider a sophisticated kind of active inference using a recursive form of expected free energy. Sophistication describes the degree to which an agent has beliefs about beliefs. We consider agents with beliefs about the counterfactual consequences of action for states of affairs and beliefs about those latent states. In other words, we move from simply considering beliefs about "what would happen if I did that" to "what I would believe about what would happen if I did that." The recursive form of the free energy functional effectively implements a deep tree search over actions and outcomes in the future. Crucially, this search is over sequences of belief states as opposed to states per se. We illustrate the competence of this scheme using numerical simulations of deep decision problems
Relevance of the slowly-varying electron gas to atoms, molecules, and solids
Under a certain scaling, the electron densities of finite systems become both
large and slowly-varying, so that the gradient expansions of the density
functionals for the Kohn-Sham kinetic and exchange energies become
asymptotically exact to order . Neutral atoms of large scale
similarly, but a cusp correction at the nucleus requires generalizing the
gradient expansion for exchange, producing the wrong gradient coefficient in
the slowly-varying limit. Meta-generalized gradient approximations (meta-GGA's)
recover both the slowly-varying and large- limits. GGA correlation energies
of large-Z atoms are found to be accurate.Comment: 5 pages, 4 figures, submitted at PR
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