Hefei University of Technology

About: Hefei University of Technology is a education organization based out in Hefei, China. It is known for research contribution in the topics: Computer science & Microstructure. The organization has 28093 authors who have published 24935 publications receiving 324989 citations.

Total-factor energy efficiency evaluation of Chinese industry by using two-stage DEA model with shared inputs

Abstract: Chinese industry has developed greatly since China implemented its “reform and opening-up” policy in 1978. With the rapid development of industry, the problems of growing energy consumption and environmental pollution are drawing increasing attention from government managers and scholars. This paper divides industrial systems into two stages, an energy utilization stage and a pollution treatment stage, for accurately evaluating the total-factor energy efficiency as well as the overall efficiency. We build a new two-stage data envelopment analysis model with shared inputs to open the “black box” of efficiency measurement in traditional energy efficiency methods. Applying the model to data for Chinese regions, we can display the advantages and disadvantages of these two stages of industry. The results show that (1) the performance of Chinese industry improved during the years 2006–2010; (2) the energy utilization stage performance was better than that of the pollution treatment stage, but the gaps reduced year by year; and (3) energy efficiency increased during this period. Based on these results, some policy recommendations are given.

Synthesis of nano-MoS2/TiO2 composite and its catalytic degradation effect on methyl orange

Abstract: A nano-MoS2/TiO2 composite was synthesized in H2 atmosphere by calcining a MoS3/TiO2 precursor, which was obtained via a quick deposition of MoS3 on anatase nano-TiO2 under a strong acidic condition The obtained nano-MoS2/TiO2 composite was characterized by X-ray diffraction spectroscopy, Brunauer–Emmett–Teller (BET) surface area, scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive spectrometry, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy The results show that the composite had a high BET surface area because of its small size and irregularly layered structure MoS2 in the composite was composed of typical layered structures with thicknesses of 2–8 nm and lengths of 10–40 nm The composite contained a wide and intensive absorption at 400–700 nm, which is in the visible light region, and presented a positive catalytic effect on removing methyl orange from the aqueous solution The catalytic activity of the composite was influenced by the initial concentration of methyl orange, the amount of the catalyst, the pH value, and the degradation temperature In addition, the composite catalyst could be regenerated and repeatedly used via filtration three times The deactivating catalyst could be reactivated after catalytic reaction by heating at 450 °C for 30 min in H2

Conversion of 1T-MoSe2 to 2H-MoS2xSe2-2x mesoporous nanospheres for superior sodium storage performance.

Abstract: S-Doped 2H-MoSe2 (i.e., 2H-MoS2xSe2−2x) mesoporous nanospheres assembled from several-layered nanosheets are synthesized by sulfurizing freshly-prepared 1T-MoSe2 nanospheres, and they serve as a robust host material for sodium storage. The sulfuration treatment is found to be beneficial for removing surface/interface insulating organic contaminants and converting the 1T phase to the 2H phase with improved crystallinity and electrical conductivity. These result in significantly enhanced sodium storage performance, including charge/discharge capacity, first Coulombic efficiency, cycling stability, and rate capability. Coupled with benefits from in situ carbon modification and its mesoporous morphology, the 2H-MoS2xSe2−2x (x = 0.22) nanosphere anode can maintain a reversible capacity of 407 mA h g−1 after 100 cycles with no observable capacity fading at a high current density of 2.0 A g−1. This value is much higher than those of the anode fabricated with the freshly-prepared 1T-MoSe2 (95 mA h g−1) and the annealed 2H-MoSe2 (144 mA h g−1) samples. As the current density rises from 0.05 to 5.0 A g−1 (100-fold increase), the discharge capacity retention is significantly increased from 39% before sulfuration to 65% after sulfuration. This superior electrochemical performance of the 2H-MoS2xSe2−2x electrode suggests a promising way to design advanced sodium host materials by surface/interface engineering.

Phase transition behavior of HPMC-AA and preparation of HPMC-PAA nanogels

Abstract: The lower critical solution temperature (LCST) of hydroxypropyl methylcellulose (HPMC) under mixing with acrylic acid (AA) monomer has been studied by turbidity measurements. It has been found that the LCST of the HPMC was drastically reduced from 60°C to 38°C with the increase of the concentration of AA, while the HPMC is kept at 0.5wt%. The driving force shifting the LCST is attributed to the hydrogen bonding and hydrophobic interaction of the molecules. Then surfactant-free HPMC-PAA nanogels have been synthesized via the polymerization of AA monomer with the collapsed HPMC as a template or core at their LCST, using KPS and TEMED as redox initiator in the presence of BIS as cross-linking agent. HPMC-PAA nanogels have 50∼150 nm diameters characterized by transmission electron microscope and dynamic light scattering. The HPMC-PAA nanogels exhibit the temperature phase transition behaviors, and these nanogels' volume phase transition temperature is close to the LCST of HPMC/AA system.