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Carbon-coated SnO2 nanocomposites were synthesized successfully by the hydrothermal method and carbonization at 500 °C with glucose and SnCl2·2H2O as precursor materials. The SnO2/C nanocomposites were characterized by various techniques such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Raman spectra, and electrochemical analyses. It was demonstrated that SnO2/C-0, SnO2/C-5, SnO2/C-15, SnO2/C-30, and SnO2/C-50 had initial discharge capacities of 1359.2, 1626.8, 2124.9, 1525.8, and 1349.4 mAhg−1, respectively. In particular, the SnO2/C-15 sample exhibited excellent high reversible lithium storage capacity, good rate capability, and cycling stability. The electrodes show a long cycling ability and high charge/discharge capacity due to the presence of carbon. [ABSTRACT FROM AUTHOR]

In this study, silica-gel (SG)-supported deep eutectic solvent (DES) with a different loading dosage as the novel nanocomposite materials has been synthesized by sol–gel method. And the supported nanocomposite materials were used as the catalyst for the synthesis of 1,10-phenanthroline from the 8-aminoquinoline and acrolein. The properties and structure of catalysts were characterized by Fourier transform infrared, N2 adsorption–desorption, scanning electron microscopy, thermogravimetric analysis and elemental analysis techniques. It was found that the 12%DES/SG catalyst with the best catalytic activity possessed the suitable specific surface area 132 m2/g and 12% loading amount of DES, which combines the excellent properties of mesoporous materials and DES. The result of thermogravimetric analysis was exhibited that the nanocomposite materials could not be decomposed below 240 °C, which can be used as a stable catalytic material under reaction conditions. Furthermore, the effect of reaction parameters such as reaction temperature and catalyst amount, molar ratio of 8-aminoquinoline and acrolein and reaction time was also studied. Under the optimal process parameters, within the optimum parameters: 130 °C, acrolein: 8-AQ = 2:1, catalyst amount 20 wt%, and time 4 h, the conversion of 8-aminoquinoline and selectivity of 1,10-phenanthroline were 83.8% and 84.3%, respectively. Otherwise, the catalyst can be separated from the reaction system and reused. Therefore, the silica-gel-supported deep eutectic solvent nanocomposite materials can be considered as a potential catalytic material for the synthesis of 1,10-phenanthroline and other nitrogen-containing heterocyclic organic chemical intermediates. Replacing traditional sulfuric acid and hydrochloric acid with silica-gel-supported deep eutectic solvents as new nanocomposite catalysts provides a more efficient, greener and more economical strategy for the synthesis of 1,10-phenanthroline. [ABSTRACT FROM AUTHOR]

The random distribution of graphene in epoxy matrix hinders the further applications of graphene-epoxy composites in the field of tribology. Hence, in order to fully utilize the anisotropic properties of graphene, highly aligned graphene-epoxy composites (AGEC) with horizontally oriented structure have been fabricated via an improved vacuum filtration freeze-drying method. The frictional tests results indicated that the wear rate of AGEC slowly increased from 5.19×10−6 mm3/(N·m) to 2.87×10−5 mm3/(N·m) with the increasing of the normal load from 2 to 10 N, whereas the friction coefficient (COF) remained a constant of 0.109. Compared to the neat epoxy and random graphene-epoxy composites (RGEC), the COF of AGEC was reduced by 87.5% and 71.2%, and the reduction of wear rate was 86.6% and 85.4% at most, respectively. Scanning electron microscope (SEM) observations illustrated that a compact graphene self-lubricant film was formed on the worn surface of AGEC, which enables AGEC to possess excellent tribological performance. Finally, in light of the excellent tribological properties of AGEC, this study highlights a pathway to expand the tribological applications of graphene-epoxy composites. [ABSTRACT FROM AUTHOR]

The sustainable development of the economy is a key issue of global concern. Green total factor productivity (GTFP) combining economic growth with resources and the environment can evaluate the quality of economic development comprehensively and accurately. In this paper, super slack-based measure (Super-SBM) model and Malmquist-Luenberger (ML) index were used to calculate GTFP. The trend of industrial GTFP in China's 30 provinces from 2006–2015 was analyzed. Furtherly, a dynamic panel model was used to discuss the impact of trade openness on GTFP. The results showed that (1) the growth rate of GTFP rose from 2007 to 2011 and declined significantly from 2011 to 2015, and GTFP only achieved positive growth in 2011; (2) the growth rate of GTFP in the eastern region was higher than that in the central and western regions; (3) the trend of technical progress change (MLTECH) index was highly consistent with that of ML index. That was, technical progress played a major role in the variation of GTFP; (4) trade openness could significantly improve China's GTFP. Every 1% increase in trade openness could increase GTFP by 0.097% on average. It is advisable to implement differentiated economic development and environmental policies in different regions. Meanwhile, relevant measures can be taken to promote import and export trade, such as encouraging companies to increase investment in green technology research and development, optimizing the trade environment. [ABSTRACT FROM AUTHOR]

The flowerlike copper sulfide (CuS)/reduced graphene oxide (rGO) composites were prepared successfully by the hydrothermal method. The active anodic material was characterized by Raman spectroscopy, thermogravimetric analyses (TGA), transmission electron microscopy (TEM), and electrochemical techniques. TEM images showed that the flowerlike CuS is well combined with rGO. The electrochemical tests indicate that the presence of rGO improves the electrochemical performance of the CuS, achieving an initial high discharge capacity of 3401 mAh g−1 and initial charge capacity of 1064 mAh g−1, superior to that exhibited for pure CuS (765.2 mAh g−1 and 318.9 mAh g−1). The reason for this is that the addition of rGO increases the surface area and conductivity of the material. The changes enable the composite material more effectively to adapt to the severe volume changes during charging and discharging. [ABSTRACT FROM AUTHOR]

In this study, three different choline chloride-based deep eutectic solvents were synthesized. And it is the first time to synthesize 1,10-phenanthroline through an improved Skraup reaction using deep eutectic solvent as the new catalyst from acrolein and 8-aminoquinoline. The deep eutectic solvents were characterized by Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (1H NMR), pH/mV meter, and thermogravimetric analysis (TGA). The research results show that the deep eutectic solvent formed by sulfanilic acid and choline chloride has the strongest acidity and highest catalytic active among the three deep eutectic solvents. Besides, the impacts of reaction parameters and molar ratio of raw materials on the reaction were also investigated. Under the optimized reaction conditions, the maximum selectivity and yield of 1,10-phenanthroline were achieved as 84.6 and 75.6%, respectively. The synthesis method, meanwhile, also has simple preparation process and low cheaper catalyst raw. Replacing traditional sulfuric acid and hydrochloric acid with deep eutectic solvents (DESs) as new catalysts provides a more efficient, greener and more economical strategy for the synthesis of 1,10-phenanthroline by a new improved Skraup reaction. [ABSTRACT FROM AUTHOR]

Studies the influence of gravity waves on the sodium layer by using a linear photochemical-dynamical coupling gravity wave model. Details of the model, which includes the background photochemistry and the photochemical reactions in the sodium layer; Calculation of amplitude and phase difference in the sodium mixing ratio to gravity waves; Indication that the lower part of the sodium layer is most sensitive to gravity waves; How temperature fluctuation is linked with in phase and out of phase conditions of the sodium mixing ratio.