No abstract

First-principles calculations of the thermal conductivity of two-dimensional materials have recently attracted a great deal of attention. The choice of the exchange-correlation (XC) and pseudopotential (PP) is a crucial step towards an accurate first-principles calculation using density functional theory (DFT). This work investigates the sensitivity of the intrinsic thermal conductivity and phonon properties of graphene to the choice of XC and PP in the temperature range of 300–550 K, using first-principles DFT simulations and an iterative solution of the Boltzmann transport equation. We consider six XC-PP combinations (LDA-NC, LDA-US, PBEsol-US, LDA-PAW, PBE-PAW, and PBEsol-PAW). Our results showed that the choice of XC-PP combination results in significant discrepancies, in the range of 5442–8677 W m−1 K−1, among predicted thermal conductivities at room temperature. The LDA-NC and PBE-PAW combinations predicted the thermal conductivities in best agreement with available experimental data. The phonon properties revealed that these discrepancies are mainly due to variations in the prediction of phonon lifetimes and Grüneisen parameters from different XC-PP combinations.

The Tomographic Quantitative Electroencephalography (qEEGt) toolbox is integrated with the Montreal Neurological Institute (MNI) Neuroinformatics Ecosystem as a docker into the Canadian Brain Imaging Research Platform (CBRAIN). qEEGt produces age-corrected normative Statistical Parametric Maps of EEG log source spectra testing compliance to a normative database. This toolbox was developed at the Cuban Neuroscience Center as part of the first wave of the Cuban Human Brain Mapping Project (CHBMP) and has been validated and used in different health systems for several decades. Incorporation into the MNI ecosystem now provides CBRAIN registered users access to its full functionality and is accompanied by a public release of the source code on GitHub and Zenodo repositories. Among other features are the calculation of EEG scalp spectra, and the estimation of their source spectra using the Variable Resolution Electrical Tomography (VARETA) source imaging. Crucially, this is completed by the evaluation of z spectra by means of the built-in age regression equations obtained from the CHBMP database (ages 5–87) to provide normative Statistical Parametric Mapping of EEG log source spectra. Different scalp and source visualization tools are also provided for evaluation of individual subjects prior to further post-processing. Openly releasing this software in the CBRAIN platform will facilitate the use of standardized qEEGt methods in different research and clinical settings. An updated precis of the methods is provided in Appendix I as a reference for the toolbox. qEEGt/CBRAIN is the first installment of instruments developed by the neuroinformatic platform of the Cuba-Canada-China (CCC) project.

A first-principles study is conducted to investigate the effect of biaxial tensile strain on phonon properties and thermal conductivity of buckled phosphorene and arsenene, novel two-dimensional (2D) materials of group-VA.