This paper first builds a rule-based fuzzy representation of shape context and then present a multi-clue based fuzzy shape context approach (MFSC) using combination of geometric information and graph transduction. The MFSC takes complexity of object shape into account. In this approach, the distance between arbitrary two sampled points on any shape is redefined and graph transduction is used to correct and compensate training error. Furthermore, we propose a new fuzzy shape context approach based on both multi-clue and state reservoir computing. The experimental results show that the accuracy of detection achieved by our new approach on Kimia-216 and Kimia-99 datasets reaches up to 99.35% and 98.56%, respectively, which outperforms that of all the state-of-the-art shape context approaches.

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The dissociation of nitrogen trifluoride (NF3) is an important topic of study because the molecule is a highly dangerous greenhouse gas that can persist in the atmosphere for 740 years. In this study, changes in the geometry, orbital energy, spectral properties, and dissociation properties of NF3 when an external electric field was applied were studied by density functional theory. Results show that when the strength of the electric field was increased, the N–3F bond length became longer until it broke, and the energy gap decreased gradually. The dissociation barrier in the potential energy curve gradually decreased with the increase in the electric field strength. When the applied electric field reached 0.05 a.u., the dissociation barrier disappeared, indicating that under the action of a strong applied electric field, NF3 is degraded because of fracture of the N–3F bond. When the application of the electric field was continued, the potential barrier disappeared and dissociation occurred when the N–4F bond was scanned. The stepwise dissociation of nitrogen trifluoride molecules occurred under an electric field intensity of 0.05 a.u. The concerted dissociation of the N–3F and N–4F bonds occurred at an electric field intensity of 0.09 a.u. When the electric field direction was in the negative direction of the z-axis, the NF3 dissociated but no concerted dissociation occurred. These results offer insight into the degradation mechanism under an applied electric field.

Tea polyphenols are essential components that give tea its medicinal properties. Methanol and water are frequently used as solvents in the extraction of polyphenols. Hydrogen‐bonding interactions are significant in the extraction reaction. Density functional theory (DFT) techniques were used to conduct a theoretical investigation on the hydrogen‐bonding interactions between methanol or water and epicatechin, an abundant polyphenol found in tea. After first analyzing the epicatechin monomer's molecular geometry and charge characteristics, nine stable epicatechin (EC) H2O/CH2OH complex geometries were discovered. The presence of hydrogen bonding in these improved structures has been proven. The calculated hydrogen bond structures are very stable, among which the hydrogen bond bonded with a hydroxyl group has higher stability. The nine complex structures’ hydrogen bonds were thought to represent closed‐shell‐type interactions. The interaction energy with 30O‐31H on the epicatechin benzene ring is the strongest in the hydrogen bond structure. While the other hydrogen bonds were weak in strength and mostly had an electrostatic nature, the hydrogen bonds between the oxygen atoms in H2O or CH2OH and the hydrogen atoms of the hydroxyl groups in epicatechin were of moderate strength and had a covalent character. Comparing the changes in the hydrogen bond structure vibration peak, the main change in concentration peak is the hydrogen bond vibration peak in the complex. Improved the study on the hydrogen bond properties of CH2OH and H2O of EC.

Sulfuryl fluoride (SO 2 F 2 ) is a powerful greenhouse gas that threatens human health. It is essential to study the dissociation mechanism of SO 2 F 2 under external electric fields (EEFs). Based on M06-2X/6-311G(d, p) level, the stepwise and concerted dissociation properties of SO 2 F 2 have been investigated under EEFs, including the dipole moment, bond lengths, total energy, orbital energy level distribution, and infrared spectrum. With increasing external-electric-field intensity, the 1S-4F and 1S-5F bonds become longer, the total energy decreases, and the energy gap decreases. Infrared spectroscopy shows that the vibration frequencies of the 1S-4F and 1S-5F bonds decrease as the electric-field intensity increases, and a significant red shift occurs. Time-dependent density functional theory was used to calculate the ultraviolet-visible absorption spectrum. Additionally, the potential-energy curves along the 1S-4F and 1S-5F bonds under electric fields were calculated. The results show that stepwise dissociation of the 1S-4F and 1S-5F bonds occur when F = 0.08 and 0.06 a.u., respectively. Corrected dissociation occurs when F = 0.95 a.u. The spectrum and dissociation mechanism of SO 2 F 2 under EEFs provide a basic understanding of the molecular structure and degradation kinetics of SO 2 F 2 , and it provides insight into decomposition of SO 2 F 2 .