When used as filling aggregates, the physical and mechanical properties of gangue and fly ash are crucial for the design of filling and transportation systems. The mineral composition of gangue and fly ash affects the filling body’s strength, and the fluidity of the slurry affects the mining engineering process. In this study, gangue and fly ash samples were characterized by X-ray diffraction to ensure their suitability as filling materials. Tests were carried out with an Intelligent Torque Rheometer, and the optimal ratio of the slurry’s components was determined. After fitting the data using ORIGIN software, the following curves were obtained: (1) rheological parameters versus slurry mass fraction; (2) rheological parameters versus component ratio. On the basis of the curves, the recommended ratio of the components in the paste-like slurry was determined. We found that the mass concentration of the slurry must be kept strictly below 78%, and the optimal slurry composition includes coal gangue, fly ash, and a gelling agent at a weight ratio of 8:3:1. In order to illustrate the effectiveness of the filling technology, surface sink curves from different filling techniques in two closely situated positions of the Xinyang Coal Mine were compared. The results showed that the use of a paste-like slurry can effectively reduce surface subsidence. Furthermore, it will lead to cost-effective engineering designs for the sustainable development of coal mines.

A field study was conducted to investigate the deposit formation of the low-pressure economizer (LPE) in a 330 MW thermal power plant. The deposits on the LPE were inspected visually, and eight deposit samples were collected at the inlet and outlet of the LPE according to the site conditions. The samples were characterized by X-ray fluorescence, X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy, and particle size analysis. The results showed that the thick deposits on the supporting tubes at the LPE inlet were mainly due to the ash particles that had absorbed the H2SO4 condensate in the flue gas before the LPE inlet. NH4HSO4 began to form on the heat-exchange tubes at the LPE inlet. Both the H2SO4 condensation and NH4HSO4 formation stimulated the deposit formation on the heat-exchange tubes at the LPE inlet. The plugging of the heat-exchange tubes at the LPE outlet was primarily induced by the condensation of much more H2SO4. H2SO4 and NH4HSO4 could also react with the fly ash to form sulfates. The LPE deposition mechanism was discussed, and the coupling model of the H2SO4, NH4HSO4, and fly ash behaviors during the deposit formation under different temperature conditions was proposed.

In this paper, the Food-grade sea cucumber / gelatin nanofiber was for the first time successfully prepared with electrospinning method. With the help of the infrared spectroscopy and X-ray diffraction, this paper analyzed the content of the nanosea cucumber powder and gelatin as well as the impact of different preparation methods on the crystalline of the Fiber membrane. Furthermore, Scanning electron microscope (SEM) was utilized to observe the fiber morphology, and thus discuss the best content of gelatin. The Experimental result manifested that as electrospinning method was used in preparing the Food-grade sea cucumber / gelatin nanofiber membrane, the nanosea cucumber powder and gelatin dispersed well in the fiber membrane, while it did worse in the crystalline of membrane. As the Gelatin content of the spinning solution is 10 wt. %, the spinnabiliy as well as its fiber-forming properties is of optimum.

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Erbium ytterbium co-doped super-fluorescent fiber source (EYD-SFS) has been simulated by a theoretical model based on rate equations and power transfer equations. The output performances of four basic structures of EYD-SFS have been expressed, and it indicated that the DPF structure is a preferable structure. The dependence of output power, mean wavelength and bandwidth stability on the pump fiber length and the concentration of Er3+ and Yb3+ have also been studied. The results indicated with a proper doping concentration of Er3+ and Yb3+ of 6.0 × 1026 ions/m3 and 1.0 × 1027 ions/m3, the optimal gain fiber length is 3.6 cm. In this condition, good performances of DPF structure of EYD-SFS have been achieved.