58,228 research outputs found
Seasonal Flight Patterns of Miridae (Hemiptera) in a Southern Illinois Black Walnut Plantation
The seasonal flight patterns of 92 species of Miridae collected in window traps in a southern Illinois black walnut plantation are compared with similar data from a North Carolina black walnut plantation. Flying height distributions and seasonal flight activities of Amblytylus nasutus, Deraeocoris nebulosus, Leptopterna dolabrata, Lopidea heidemanni, Lygus lineolaris, and Plagiognathus politus are considered in detail. Six species are newly recorded for Illinois
Cathodoluminescence of enstatite from chondritic and achondritic meteorites and its selenological implications Technical report, 1 Sep. 1967 - 1 Jul. 1968
Cathodoluminescence of enstatite from chondritic and achondritic meteorites and selenological implication
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Linking the anomaly initialization approach to the mapping paradigm: a proof-of-concept study
Seasonal-to-decadal predictions are initialized using observations of the present climatic state in full field initialization (FFI). Such model integrations undergo a drift toward the model attractor due to model deficiencies that incur a bias in the model. The anomaly initialization (AI) approach reduces the drift by adding an estimate of the bias onto the observations at the expense of a larger initial error.
In this study FFI is associated with the fidelity paradigm, and AI is associated with an instance of the mapping paradigm, in which the initial conditions are mapped onto the imperfect model attractor by adding a fixed error term; the mapped state on the model attractor should correspond to the nature state. Two diagnosis tools assess how well AI conforms to its own paradigm under various circumstances of model error: the degree of approximation of the model attractor is measured by calculating the overlap of the AI initial conditions PDF with the model PDF; and the sensitivity to random error in the initial conditions reveals how well the selected initial conditions on the model attractor correspond to the nature states. As a useful reference, the initial conditions of FFI are subjected to the same analysis.
Conducting hindcast experiments using a hierarchy of low-order coupled climate models, it is shown that the initial conditions generated using AI approximate the model attractor only under certain conditions: differences in higher-than-first-order moments between the model and nature PDFs must be negligible. Where such conditions fail, FFI is likely to perform better
Correlations in hot and dense quark matter
We present a relativistic three-body equation to investigate three-quark
clusters in hot and dense quark matter. To derive such an equation we use the
Dyson equation approach. The equation systematically includes the Pauli
blocking factors as well as the self energy corrections of quarks. Special
relativity is realized through the light front form. Presently we use a
zero-range force and investigate the Mott transition.Comment: 6 pages, 4 figure, Few-Body Systems style file
Numerical Models for the Diffuse Ionized Gas in Galaxies. II. Three-dimensional radiative transfer in inhomogeneous interstellar structures as a tool for analyzing the diffuse ionized gas
Aims: We systematically explore a plausible subset of the parameter space
involving effective temperatures and metallicities of the ionizing stellar
sources, the effects of the hardening of their radiation by surrounding leaky
HII regions with different escape fractions, as well as different scenarios for
the clumpiness of the DIG, and compute the resulting line strength ratios for a
number of diagnostic optical emission lines.
Methods: For the ionizing fluxes we compute a grid of stellar spectral energy
distributions (SEDs) from detailed, fully non-LTE model atmospheres that
include the effects of stellar winds and line blocking and blanketing. To
calculate the ionization and temperature structure in the HII regions and the
diffuse ionized gas we use spherically symmetric photoionization models as well
as state-of-the-art three-dimensional (3D) non-LTE radiative transfer
simulations, considering hydrogen, helium, and the most abundant metals.
Results: We provide quantitative predictions of how the line ratios from HII
regions and the DIG vary as a function of metallicity, stellar effective
temperature, and escape fraction from the HII region. The range of predicted
line ratios reinforces the hypothesis that the DIG is ionized by (filtered)
radiation from hot stars; however, comparison of observed and predicted line
ratios indicates that the DIG is typically ionized with a softer SED than
predicted by the chosen stellar population synthesis model. Even small changes
in simulation parameters like the clumping factor can lead to considerable
variation in the ionized volume. Both for a more homogeneous gas and a very
inhomogeneous gas containing both dense clumps and channels with low gas
density, the ionized region in the dilute gas above the galactic plane can
cease to be radiation-bounded, allowing the ionizing radiation to leak into the
intergalactic medium.Comment: 21 pages, 9 figures, accepted by A&
Applications of luminescence techniques to the study of the lunar surface
Optical fluorescence spectra of rock-forming minerals for identifying mineral grains found on lunar surfac
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