Southwest University of Science and Technology

About: Southwest University of Science and Technology is a education organization based out in Mianyang, China. It is known for research contribution in the topics: Adsorption & Graphene. The organization has 10017 authors who have published 8923 publications receiving 94850 citations. The organization is also known as: Xīnán Kējìdàxué.

Modeling Method of the Grey GM(1,1) Model with Interval Grey Action Quantity and Its Application

Abstract: GM(1,1) is a univariate grey prediction model with incomplete structural information, in which the real number form of the simulation or prediction data does not conform to the Nonuniqueness Principle of Grey theoretical solution. In light of the network model of GM(1,1), the connotation of grey action quantity is systematically analyzed and the interval grey number form of grey action quantity is restored under uncertain influencing factors. A novel GM(1,1) model is then constructed. The new model has the basic characteristics of the grey model under incomplete information. Moreover, it can be fully compatible with the traditional GM(1,1) model. The developed model is employed to the natural gas consumption prediction in China, showing that its predicting rationality is much better than that of the traditional GM(1,1) model. It is worth mentioning that, for the first time, the grey property of GM(1,1) has been restored in structure, which is of significance for both academia and industry.

A density functional study on the adsorption of hydrogen molecule onto small copper clusters

Abstract: An all-electron scalar relativistic calculation on the adsorption of hydrogen molecule onto small copper clusters has been performed by using density functional theory with the generalized gradient approximation (GGA) at PW91 level. Our results reveal that after adsorption of H2 molecule, the Cu–Cu interaction is strengthened and the H–H interaction is weakened, the reactivity enhancement of H2 molecule is obvious. The VIPs, HLGs and VEAs of Cu n H2 clusters show an obvious odd–even oscillation. It is suggested that the H2 molecule is more favourable to be adsorbed by the even-numbered small copper clusters. Meanwhile, the odd–even alteration of magnetic moments is also observed and may be served as the material with tunable code capacity of ‘0’ and ‘1’ by adsorbing hydrogen molecule onto odd or even-numbered small copper clusters. Some discrepancies of dissociative adsorption between our work and previous works are found and may be understood in terms of the electron pairing effect and the scalar relativistic effect.

Effect of glycerol on the preparation of phosphogypsum-based CaSO4·0.5H2O whiskers

Abstract: Phosphogypsum-based CaSO4·0.5H2O whiskers were successfully prepared in the presence of glycerol by hydrothermal method. The action mechanism of glycerol on the morphology of CaSO4·0.5H2O whiskers was investigated and discussed in detail. The as-prepared products were characterized by X-ray powder diffraction spectrometer, scanning electron microscopy, Fourier transform infrared spectrometer, and thermal analyzer. The main phase of the as-prepared products was CaSO4·0.5H2O, and the morphology was uniform fiber. Moreover, the aspect ratio and productivity of the as-prepared CaSO4·0.5H2O whiskers increased with the concentration of glycerol. Even whiskers with mean length of 38–83 μm, mean width of 1.33–0.73 μm, aspect ratio of 29–118, and productivity of 89–96 % were obtained under the condition of glycerol/water volume ratio of 10–100 %. As far as mechanism was concerned, the hydroxyl groups of glycerol adsorbed and occupied the vacancies of Ca sites on (001) plane of CaSO4·0.5H2O whiskers, and however, on (100) plane, hydroxyl groups of glycerol adsorbed mainly on Ca sites and formed hydrogen bond layered structure on both sides of that, which should be the reason that CaSO4·0.5H2O whiskers grew along the c-axis observed in this study.

Selective chemiluminescent sensor for detection of mercury(II) ions using non-aggregated luminol-capped gold nanoparticles

Abstract: A selective chemiluminescent sensor was developed for the detection of mercury(II) ions (Hg 2+ ) in environmental water and soil supernatant samples using non-aggregated luminol-capped gold nanoparticles (AuNPs). Luminol-capped AuNPs can react with silver nitrate (AgNO 3 ) under alkaline environment, generating a strong chemiluminescence (CL) emission because AuNPs had excellent catalytic activity for luminol-AgNO 3 CL system. However, when Hg 2+ was added to the solution of luminol-capped AuNPs, it would be adsorbed on the surface of luminol-capped AuNPs according to the inherent affinity of AuNPs for Hg 2+ . The presence of Hg 2+ significantly inhibited the catalytic activity of AuNPs, leading to CL quenching. With the increasing of Hg 2+ concentration, the CL intensity gradually decreased. Under the optimal detection conditions, the developed CL sensor showed a good linear relationship in range of 10–600 nM with a limit of detection of 1 nM at a signal-to-noise ratio of three which was below the maximum allowable concentration for Hg 2+ in drinking water (10 nM) defined by United States Environmental Protection Agency. Also, the developed CL sensor exhibited high selectivity toward Hg 2+ over other environmentally relevant metal ions at high concentrations (500 μM).