After gas drainage,the outburst seam is dry and,consequently,during subsequent mechanized mining,unwanted dust production is extensive.Because the hard dustfall typically has a small particle size it contains a high p...After gas drainage,the outburst seam is dry and,consequently,during subsequent mechanized mining,unwanted dust production is extensive.Because the hard dustfall typically has a small particle size it contains a high percentage of respirable dust.Considering these factors,this paper improved the efficiency of dustfall by reducing the surface tension of the liquid used as a wetting agent,then configuring five kinds of wetting agents by adopting various doses and types of surfactants,neutral inorganic salts and chemical additives,etc.After purchasing DA-85 and SRJ-1 wetting agent,the surface tension and critical micelle concentration of seven kinds of wetting agents were measured using the capillary rise method.Wetting agent A was confirmed to have the best comprehensive effect.The experiments were optimized by measuring and comparatively analyzing contact angles of pure water,SRJ-1 wetting agent and wetting agent A on the surface of different coal samples using a contact angle measurement instrument(HARKESPCA).By comparative analysis,dust-proof effects of seam,dynamic pressure water infusion and highpressure spray in the tunneling face at the Daning coal mine using pure water,wetting agent SRJ-1and A,it was determined that after using wetting agent A,the average dust concentration in the place of the mining machine driver,10 m and 110 m away from the tunneling front is approximately 300 mg/m^3,240 mg/m^3 and 100 mg/m^3,respectively.This practice increased the dust-proof efficiency dramatically and achieved a good comprehensive dust-proof effect.展开更多
We report the SERS enhancements of Raman forbidden surface modes of TiO<sub>2</sub> in different sized TiO<sub>2</sub> crystals. This current study utilizes the relationship between the vibroni...We report the SERS enhancements of Raman forbidden surface modes of TiO<sub>2</sub> in different sized TiO<sub>2</sub> crystals. This current study utilizes the relationship between the vibronic coupling and the degree of charge-transfer to explain the differences of Surface Enhanced Raman Scattering (SERS) enhancements. Our study shows a direct correlation between the degree of charge-transfer and vibronic coupling. This relationship suggests that charge-transfer between the N-719 dye and TiO<sub>2</sub> due to vibronic coupling plays a fundamental role in SERS enhancements. Furthermore, this study shows a strong dependence of the enhancements of the N-719 dye molecular modes to that of the surface modes. This indicates that the mechanism that governs the enhancements of the surface modes in TiO<sub>2</sub> crystals most likely also dictates the enhancements of the N-719 dyes.展开更多
基金partly supported by the National Natural Science Foundation of China (No.51404263)the National Natural Science Foundation of Jiangsu Province (No.BK20130203)+3 种基金the Coal Mine Joint Funds of the National Natural Science Foundation of China (No.51134023)the State Key Laboratory Cultivation Base for Gas Geology and Gas Control (No.WS2013A05)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the independent study for State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology (No.SKLCRSM09X04)
文摘After gas drainage,the outburst seam is dry and,consequently,during subsequent mechanized mining,unwanted dust production is extensive.Because the hard dustfall typically has a small particle size it contains a high percentage of respirable dust.Considering these factors,this paper improved the efficiency of dustfall by reducing the surface tension of the liquid used as a wetting agent,then configuring five kinds of wetting agents by adopting various doses and types of surfactants,neutral inorganic salts and chemical additives,etc.After purchasing DA-85 and SRJ-1 wetting agent,the surface tension and critical micelle concentration of seven kinds of wetting agents were measured using the capillary rise method.Wetting agent A was confirmed to have the best comprehensive effect.The experiments were optimized by measuring and comparatively analyzing contact angles of pure water,SRJ-1 wetting agent and wetting agent A on the surface of different coal samples using a contact angle measurement instrument(HARKESPCA).By comparative analysis,dust-proof effects of seam,dynamic pressure water infusion and highpressure spray in the tunneling face at the Daning coal mine using pure water,wetting agent SRJ-1and A,it was determined that after using wetting agent A,the average dust concentration in the place of the mining machine driver,10 m and 110 m away from the tunneling front is approximately 300 mg/m^3,240 mg/m^3 and 100 mg/m^3,respectively.This practice increased the dust-proof efficiency dramatically and achieved a good comprehensive dust-proof effect.
文摘We report the SERS enhancements of Raman forbidden surface modes of TiO<sub>2</sub> in different sized TiO<sub>2</sub> crystals. This current study utilizes the relationship between the vibronic coupling and the degree of charge-transfer to explain the differences of Surface Enhanced Raman Scattering (SERS) enhancements. Our study shows a direct correlation between the degree of charge-transfer and vibronic coupling. This relationship suggests that charge-transfer between the N-719 dye and TiO<sub>2</sub> due to vibronic coupling plays a fundamental role in SERS enhancements. Furthermore, this study shows a strong dependence of the enhancements of the N-719 dye molecular modes to that of the surface modes. This indicates that the mechanism that governs the enhancements of the surface modes in TiO<sub>2</sub> crystals most likely also dictates the enhancements of the N-719 dyes.
