3,747 research outputs found
Energy translation and Proper-Time Eigenstates
The usual quantum mechanics describes the mass eigenstates. To describe the
proper-time eigenstates, a duality theory of the usual quantum mechanics was
developed. The time interval is treated as an operator on an equal footing with
the space interval, and the quantization of the space-time intervals between
events is obtained. As a result, one can show that there exists a zero-point
time interval.Comment: 15 pages, No figur
Carbon monoxide in an extremely metal-poor galaxy
Extremely metal-poor galaxies with metallicity below 10% of the solar value
in the local universe are the best analogues to investigating the interstellar
medium at a quasi-primitive environment in the early universe. In spite of the
ongoing formation of stars in these galaxies, the presence of molecular gas
(which is known to provide the material reservoir for star formation in
galaxies, such as our Milky Way) remains unclear. Here, we report the detection
of carbon monoxide (CO), the primary tracer of molecular gas, in a galaxy with
7% solar metallicity, with additional detections in two galaxies at higher
metallicities. Such detections offer direct evidence for the existence of
molecular gas in these galaxies that contain few metals. Using archived
infrared data, it is shown that the molecular gas mass per CO luminosity at
extremely low metallicity is approximately one-thousand times the Milky Way
value.Comment: 12 pages, 3 figures, 1 table. Supplementary data at
http://www.nature.com/article-assets/npg/ncomms/2016/161209/ncomms13789/extref/ncomms13789-s1.pd
catena-Poly[nickel(II)-bis(μ-2-aminoethanesulfonato-κ3 N,O:O′;κ3 O:N,O′)]
In the title polymeric complex, [Ni(C2H6NO3S)2]n, the NiII ion occupies a special position on an inversion centre and displays a slightly distorted octahedral coordination geometry, being linked to four sulfonate O atoms and to two N atoms of the taurine ligands. The sulfonate groups doubly bridge symmetry-related NiII centers, forming polymeric chains along the a axis
Research on a Pulmonary Nodule Segmentation Method Combining Fast Self-Adaptive FCM and Classification
The key problem of computer-aided diagnosis (CAD) of lung cancer is to segment pathologically changed tissues fast and accurately. As pulmonary nodules are potential manifestation of lung cancer, we propose a fast and self-adaptive pulmonary nodules segmentation method based on a combination of FCM clustering and classification learning. The enhanced spatial function considers contributions to fuzzy membership from both the grayscale similarity between central pixels and single neighboring pixels and the spatial similarity between central pixels and neighborhood and improves effectively the convergence rate and self-adaptivity of the algorithm. Experimental results show that the proposed method can achieve more accurate segmentation of vascular adhesion, pleural adhesion, and ground glass opacity (GGO) pulmonary nodules than other typical algorithms
N-(2-Hydroxy-5-nitrophenyl)methanesulfonamide ethanol monosolvate
In the title compound, C7H8N2O5S·C2H6O, the dihedral angle between the aromatic ring and the nitro group is 8.78 (9)° and the S atom is displaced by 0.226 (3) Å from the plane of the aromatic ring. In the crystal, the ethanol molecule is involved in hydrogen bonding to two separate sulfonamide molecules, as a donor in an O—H⋯O interaction and as an acceptor in an N—H⋯O interaction. Weak C—H⋯O hydrogen bonding is also present
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