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991.
Optics and Spectroscopy - The design of neutral nonpolarizing interference systems formed on the face of one of the two prisms that are components of an optical element in the form of a cube is... 相似文献
992.
Radiophysics and Quantum Electronics - We study experimentally the spectral characteristics of low-frequency current fluctuations in tungsten filaments of lighting lamps in the ranges of... 相似文献
993.
Natalie Hell Peter Beiersdorfer Gregory V. Brown Megan E. Eckart Richard L. Kelley Caroline A. Kilbourne Maurice A. Leutenegger Thomas E. Lockard F. Scott Porter Jörn Wilms 《X射线光谱测定》2020,49(1):218-233
X-ray astronomy and ground-based atomic physics have a long history of fruitful collaboration: Sound understanding of the underlying atomic physics is the key to reliable interpretation of the spectra from celestial sources; conversely, astronomical spectra have been used to benchmark and advance atomic physics. This interplay is about to become even more important as we enter a new era of high-resolution X-ray astrophysics with large effective collection area. Although high-resolution observations with the gratings on the Chandra and XMM-Newton observatories continue to drive new science, upcoming planned and proposed missions will open up new discovery space in the near future that is currently challenging to access: high-resolution spectroscopy on extended sources, in the Fe K band, and on short time scales. This review summarizes open questions in these areas and the design parameters for the Hitomi, XRISM, Athena, and Arcus observatories. The expected high quality of spectra taken with these observatories puts new constraints on the accuracy of atomic reference data required to take full advantage of the diagnostic potential of these spectra. 相似文献
994.
Bhalchandra D. Thatte 《Journal of Graph Theory》2020,93(2):181-202
Previously we showed that many invariants of a graph can be computed from its abstract induced subgraph poset, which is the isomorphism class of the induced subgraph poset, suitably weighted by subgraph counting numbers. In this paper, we study the abstract bond lattice of a graph, which is the isomorphism class of the lattice of distinct unlabelled connected partitions of a graph, suitably weighted by subgraph counting numbers. We show that these two abstract posets can be constructed from each other except in a few trivial cases. The constructions rely on certain generalisations of a lemma of Kocay in graph reconstruction theory to abstract induced subgraph posets. As a corollary, trees are reconstructible from their abstract bond lattice. We show that the chromatic symmetric function and the symmetric Tutte polynomial of a graph can be computed from its abstract induced subgraph poset. Stanley has asked if every tree is determined up to isomorphism by its chromatic symmetric function. We prove a counting lemma, and indicate future directions for a study of Stanley's question. 相似文献
995.
Drah A. Tomić N. Z. Kovačević T. Djokić V. Tomić M. Heinemann R. J. Marinković A. 《Mechanics of Composite Materials》2020,56(2):249-260
Mechanics of Composite Materials - Commercial γ ? Al2O3 particles, Al2O3 n, and synthesized Al2O3 doped with iron oxide (Al2O3 Fe) were used as reinforcements to enhance the toughness of... 相似文献
996.
997.
Physics of the Solid State - The results of the study of the peculiarities of changes in the electrophysical, optical, and plasmonic properties of ultrathin metallic films during the percolation... 相似文献
998.
Komolov A. S. Lazneva E. F. Gerasimova N. B. Sobolev V. S. Panina Yu. A. Pshenichnyuk S. A. Asfandiarov N. L. Handke B. 《Physics of the Solid State》2020,62(7):1245-1250
Physics of the Solid State - The formation of unoccupied electronic states and the boundary potential barrier during thermal deposition of tetracyanoquinodimethane (TCNQ) films to 7 nm in thickness... 相似文献
999.
Technical Physics - The results of experiments on the influence of a weak magnetic field on the sensitivity of powdered pentaammine (5-nytrotetrazolato-N2) cobalt(III) perchlorate to a high-current... 相似文献
1000.
Physics in Perspective - The American physicist John Wheeler once told his colleague Richard Feynman that, in case of war, “it’s better to forget physics and tell the admirals and... 相似文献