1,535 research outputs found
Characterization of graphs with equal domination and connected domination numbers
AbstractArumugam and Paulraj Joseph (Discrete Math 206 (1999) 45) have characterized trees, unicyclic graphs and cubic graphs with equal domination and connected domination numbers. In this paper, we extend their results and characterize the class of block graphs and cactus graphs for which the domination number is equal to the connected domination number
5,7-DimethoxyÂisobenzofuran-1(3H)-one
The asymmetric unit of the title compound, C10H10O4, which has been isolated from rhizoma Polygonum Cuspidatum, a Chinese folk medicine, contains two crystallographically independent molÂecules. The molÂecules are essentially planar, with a maximum deviation of 0.061 (2) Å from the best planes. The crystal packing is stabilized by weak interÂmolecular C—H⋯O hydrogen-bonding interÂactions, with a stacking direction of the molÂecules parallel to [101]
Superradiant Solid in Cavity QED Coupled to a Lattice of Rydberg Gas
We study an optical cavity coupled to a lattice of Rydberg atoms, which can
be represented by a generalized Dicke model. We show that the competition
between the atomic interaction and atom-light coupling induces a rich phase
diagram. A novel "superradiant solid" (SRS) phase is found, where both the
superradiance and crystalline orders coexist. Different from the normal second
order superradiance (SR) transition, here both the Solid-1/2 and SRS to SR
phase transitions are first order. These results are confirmed by the large
scale quantum Monte Carlo simulations.Comment: 5 pages,4 figure
Vacancies and dopants in two-dimensional tin monoxide: An ab initio study
Layered tin monoxide (SnO) offers an exciting two-dimensional (2D)
semiconducting system with great technological potential for next-generation
electronics and photocatalytic applications. Using a combination of
first-principles simulations and strain field analysis, this study investigates
the structural dynamics of oxygen (O) vacancies in monolayer SnO and their
functionalization by complementary lightweight dopants, namely C, Si, N, P, S,
F, Cl, H and H. Our results show that O vacancies are the dominant native
defect under Sn-rich growth conditions with active diffusion characteristics
that are comparable to that of graphene vacancies. Depending on the choice of
substitutional species and its concentration within the material, significant
opportunities are revealed in the doped-SnO system for facilitating
/-type tendencies, work function reduction, and metallization of the
monolayer. N and F dopants are found to demonstrate superior mechanical
compatibility with the host lattice, with F being especially likely to take
part in substitution and lead to degenerately doped phases with high open-air
stability. The findings reported here suggest that post-growth filling of O
vacancies in Sn-rich conditions presents a viable channel for doping 2D tin
monoxide, opening up new avenues in harnessing defect-engineered SnO
nanostructures for emergent technologies
Synthesis and Sensing Properties of ZnO/ZnS Nanocages
Large-scale uniform ZnO dumbbells and ZnO/ZnS hollow nanocages were successfully synthesized via a facile hydrothermal route combined with subsequent etching treatment. The nanocages were formed through preferential dissolution of the twinned (0001) plane of ZnO dumbbells. Due to their special morphology, the hollow nanocages show better sensing properties to ethanol than ZnO dumbbells. The gain in sensitivity is attributed to both the interface between ZnO and ZnS heterostructure and their hollow architecture that promotes analyte diffusion and increases the available active surface area
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