13 research outputs found
Numerical simulation of Quasi-Normal Modes in time-dependent background
We study the massless scalar wave propagation in the time-dependent
Schwarzschild black hole background. We find that the Kruskal coordinate is an
appropriate framework to investigate the time-dependent spacetime. A
time-dependent scattering potential is derived by considering dynamical black
hole with parameters changing with time. It is shown that in the quasinormal
ringing both the decay time-scale and oscillation are modified in the
time-dependent background.Comment: 10 pages, 8 figures; reference adde
Quasinormal Modes in three-dimensional time-dependent Anti-de Sitter spacetime
The massless scalar wave propagation in the time-dependent BTZ black hole
background has been studied. It is shown that in the quasi-normal ringing both
the decay and oscillation time-scales are modified in the time-dependent
background.Comment: 8 pages and 7 figure
Calcium phosphate coating on biomedical WE43 magnesium alloy pretreated with a magnesium phosphate layer for corrosion protection
Fabrication of NiFe2O4/C hollow spheres constructed by mesoporous nanospheres for high-performance lithium-ion batteries
Graphene-based electrodes for electrochemical energy storage
The ever-increasing demands for energy and environmental concerns due to burning fossil fuels are the key drivers of today's R&D of innovative energy storage systems. This paper provides an overview of recent research progress in graphene-based materials as electrodes for electrochemical energy storage. Beginning with a brief description of the important properties of single-layer graphene, methods for the preparation of graphene and its derivatives (graphene oxide and reduced graphene oxide) are summarized. Then, graphene-based electrode materials for electrochemical capacitors and lithium-ion batteries are reviewed. The use of graphene for improving the performance of lithium–sulfur and lithium–oxygen batteries is also presented. Future research trend in the development of high-powerdensity and high-energy-density electrochemical energy storage devices is analysed
Enhanced photocatalytic degradation for organic pollutants by a novel m-Bi2O4/Bi2O2CO3 photocatalyst under visible light
Solution-Processed Two-Dimensional Metal Dichalcogenide-Based Nanomaterials for Energy Storage and Conversion
Psoriasis genome-wide association study identifies susceptibility variants within LCE gene cluster at 1q21
A Review on Design Strategies for Carbon Based Metal Oxides and Sulfides Nanocomposites for High Performance Li and Na Ion Battery Anodes
International audienceCarbon-oxide and carbon-sulfide nanocomposites have attracted tremendous interest as the anode materials for Li and Na ion batteries. Such composites are fascinating as they often show synergistic effect compared to their singular components. Carbon nanomaterials are often used as the matrix due to their high conductivity, tensile strength, and chemical stability under the battery condition. Metal oxides and sulfides are often used as active material fillers because of their large capacity. Numerous works have shown that by taking one step further into fabricating nanocomposites with rational structure design, much better performance can be achieved. The present review aims to present and discuss the development of carbon-based nanocomposite anodes in both Li ion batteries and Na ion batteries. The authors introduce the individual components in the composites, i.e., carbon matrices (e.g., carbon nanotube, graphene) and metal oxides/sulfides; followed by evaluating how advanced nanostructures benefit from the synergistic effect when put together. Particular attention is placed on strategies employed in fabricating such composites, with examples such as yolk–shell structure, layered-by-layered structure, and composite comprising one or more carbon matrices. Lastly, the authors conclude by highlighting challenges that still persist and their perspective on how to further develop the technologies