23,101 research outputs found
Effects of Electrolyte Additives on Nonaqueous Redox Flow Batteries
The widespread utilization of nonaqueous redox flow batteries is hindered by the low performance. Including some kinds of additives in electrolyte is a possible and facile solution. In this chapter, the effects of carbon dioxide gas, EC/DMC, and antimony ions on the electrochemical performance of nonaqueous redox flow batteries are disclosed. The results show that the ohmic resistance of the deep eutectic solvent (DES) electrolyte reduces significantly when adding carbon dioxide gas and EC/DMC, the percentage of reduction increases with the volume percentage of EC/DMC in electrolyte, and the reaction kinetics almost keeps unchanged for carbon dioxide gas and EC/DMC additives. For the additive of antimony ions, the electrochemical reaction kinetics of active redox couple is enhanced, the diffusion coefficient of active ions also increases, and the charge transfer resistance decreases. The antimony ions electrodeposited on the surface of graphite felt contribute a catalytic effect on the electrochemical reaction so as to improve the performance. However, due to the trade-off between the enhanced kinetics and reduced active surface area, the optimum concentration of antimony ions is found to be 15 mM. In addition, the flow battery assembled with negative electrolyte containing antimony ions exhibits 31.2% higher power density than that of pristine DES electrolyte
A multiwavelength study of massive star-forming region IRAS 22506+5944
We present a multi-line study of the massive star-forming region IRAS
22506+5944. A new 6.7 GHz methanol maser was detected. 12CO, 13CO, C18O and
HCO+ J = 1-0 transition observations reveal a star formation complex consisting
mainly of two cores. The dominant core has a mass of more than 200 solar mass,
while another one only about 35 solar mass. Both cores are obviously at
different evolutionary stages. A 12CO energetic bipolar outflow was detected
with an outflow mass of about 15 solar mass.Comment: 9 pages, 4 figure
Multifractal and Network Analysis of Phase Transition
Many models and real complex systems possess critical thresholds at which the
systems shift from one sate to another. The discovery of the early warnings of
the systems in the vicinity of critical point are of great importance to
estimate how far a system is from a critical threshold. Multifractal Detrended
Fluctuation analysis (MF-DFA) and visibility graph method have been employed to
investigate the fluctuation and geometrical structures of magnetization time
series of two-dimensional Ising model around critical point. The Hurst exponent
has been confirmed to be a good indicator of phase transition. Increase of the
multifractality of the time series have been observed from generalized Hurst
exponents and singularity spectrum. Both Long-term correlation and broad
probability density function are identified to be the sources of
multifractality of time series near critical regime. Heterogeneous nature of
the networks constructed from magnetization time series have validated the
fractal properties of magnetization time series from complex network
perspective. Evolution of the topology quantities such as clustering
coefficient, average degree, average shortest path length, density,
assortativity and heterogeneity serve as early warnings of phase transition.
Those methods and results can provide new insights about analysis of phase
transition problems and can be used as early warnings for various complex
systems.Comment: 23 pages, 11 figure
StoryDroid: Automated Generation of Storyboard for Android Apps
Mobile apps are now ubiquitous. Before developing a new app, the development
team usually endeavors painstaking efforts to review many existing apps with
similar purposes. The review process is crucial in the sense that it reduces
market risks and provides inspiration for app development. However, manual
exploration of hundreds of existing apps by different roles (e.g., product
manager, UI/UX designer, developer) in a development team can be ineffective.
For example, it is difficult to completely explore all the functionalities of
the app in a short period of time. Inspired by the conception of storyboard in
movie production, we propose a system, StoryDroid, to automatically generate
the storyboard for Android apps, and assist different roles to review apps
efficiently. Specifically, StoryDroid extracts the activity transition graph
and leverages static analysis techniques to render UI pages to visualize the
storyboard with the rendered pages. The mapping relations between UI pages and
the corresponding implementation code (e.g., layout code, activity code, and
method hierarchy) are also provided to users. Our comprehensive experiments
unveil that StoryDroid is effective and indeed useful to assist app
development. The outputs of StoryDroid enable several potential applications,
such as the recommendation of UI design and layout code
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