Invariants of BT[p,q], BT(X)[p,q] and BT(Y)[p,q]

Abstract

Boron nitride nanotubes (BNNTs) have been increasingly investigated for use in a wide range of applications due to their unique physicochemical properties including high hydrophobicity, heat and electrical insulation, resistance to oxidation, and hydrogen storage capacity. They are also valued for their possible medical and biomedical applications including drug delivery, use in biomaterials, and neutron capture therapy. Chemical graph theory provides different tools to investigate different properties of nanotubes. Tools like topological invariants are useful to associate an appropriate number with a networks through which we can guess different hidden properties of under consideration network. There are more then 150 topological indices present in history, but no one gives use perfect result in predicting properties of networks. So there is always a room to introduce some new invariants that help us to gain better results. In this paper, we will introduce some new topological indices and polynomials, namely, Maxmin indices and Maxmin polynomials and, calculate results for three different boron nanotubes, boron triangular nanotube BT[p, q], boron‐α nanotube BT(X)[p, q] and boron‐α nanotube BT(Y)[p, q].

Correlation and Causation Analysis Between COVID-19 and Environmental Factors in China

“…All this information can be considered as a subset of Figure 3B in this paper, indicating that more samples are needed to obtain a more comprehensive understanding. Recently, Huang et al (2020) pointed out that the optimal temperature for COVID-19 spread was 5∼15 • C, and 70% of confirmed cases worldwide occurred between 5 and ∼15 • C, which is similar to this paper. In addition to Hubei Province, China still has 58.2% of cases in this temperature range, but only 43.2% of the temperature data (Figure 3A).…”

“…Ma et al (2020) and Wang et al (2020) have shown that temperature changes and humidity may be important factors affecting the spread of COVID-19 and mortality in COVID-19 patients. Recently, Huang et al (2020) pointed out that optimal air temperature for COVID-19 transmission is 5∼15 • C in many countries and regions in the world, and they considered the impacts of meteorological factors in the epidemic model and developed the world's first global prediction model for COVID-19 (http://covid-19.lzu.edu. cn/).…”

Enhancement of Biodiesel Production from Chicken Fat Using MgO and MgO@Na2O Nanocatalysts

“…Moreover, the MgO and MgO@Na 2 O nanoparticles had relative weight losses of 17 and 7 %, respectively. The weight loss of the catalysts in the second stage can be effected by the complete evaporation of water from their layers, completely eliminating the existing Mg(OH) 2 in the catalyst structure and changing to MgO 34. Significant weight reduction was observed in the samples by increasing the temperature from 800 to 1000 °C, and the MgO and MgO@Na 2 O catalysts had about 20 and 10 % weight loss in the whole TGA process, respectively.…”

Vertically integrated visible and near-infrared metasurfaces enabling an ultra-broadband and highly angle-resolved anomalous reflection

“…A single trapezoid-shaped antenna in place of the discrete antenna array might be used to facilitate the fabrication of the delicate device structure. [15][16][17][18][19] The scheme capitalizing on such a single antenna is expected to provide an enhanced phase gradient over a wide band, thereby rendering broadband anomalous reflection. For the supercell with a superwavelength lattice period, the angle of anomalous reflection is simply determined by the modified diffraction equation.…”

“…17 Unlike conventional blazed gratings, which tap into a sawtooth échelette profile to exhibit a maximum diffraction efficiency at a specific wavelength, the anomalous reflection is efficiently achieved throughout a broad band for the planar metasurface. 15,16 It is noted that due to the inherent shape of the antenna, the enhanced anomalous reflection is polarization-dependent and therefore the metasurface can be potentially treated as a broadband polarization beam splitter, 15 which might not be easily fulfilled using a diffraction grating. 20 Despite its vulnerability to dissipative optical loss, a plasmonic metasurface is deemed to give rise to an appreciable level of anomalous reflection beyond 80%, which can readily be applied to spectroscopy, imaging, and photovoltaics.…”