Torrefaction operation is an essential pathway for solid biofuel upgrading,and good hydrophobicity of torrefied biochar is conducive to its storage.Herein,a two-stage treatment of torrefaction followed by modification...Torrefaction operation is an essential pathway for solid biofuel upgrading,and good hydrophobicity of torrefied biochar is conducive to its storage.Herein,a two-stage treatment of torrefaction followed by modification by hexadecyltrimethoxysilane was adopted to improve the moisture resistance performance of biochar.This two-stage treatment process led to a longer torrefied microalgal biochar preservation time(60-200%improved)and great superhydrophobicity and superlipophilicity.Therefore,the modified microalgal biochar could significantly adsorb leaking oil for environmental remediation and further improve the calorific value of the biochar.The obtained results indicated that the oil adsorption capacity of modified microalgal biochar was correlated to torrefaction temperature and oil species.Specifically,the oil adsorption capacity was enhanced up to 70-80%from the modification process when comparing to raw microalga.Increasing the torrefaction temperature enhanced the adsorption quantity of the modified microalgal biochar.By adsorbing the oil,the calorific value of oilchar,namely,biochar with adsorbed oil,could be higher than 40 MJ kg^(−1).Furthermore,the pyrolysis and combustion characteristics suggested that biochar stability gradually rose as the torrefaction temperature increased.By comprehensively analyzing and comparing the fuel performance of the modified microalgal biochar with previous literature,the obtained modified microalgal biochar possessed better fuel properties and environmental sustainability.展开更多
We investigated 1-μm multimode fiber laser based on carbon nanotubes,where multiple typical pulse states were observed,including Q-switched,Q-switched mode-locked,and spatiotemporal mode-locked pulses.Particularly,st...We investigated 1-μm multimode fiber laser based on carbon nanotubes,where multiple typical pulse states were observed,including Q-switched,Q-switched mode-locked,and spatiotemporal mode-locked pulses.Particularly,stable spatiotemporal mode-locking was realized with a low threshold,where the pulse duration was 37 ps and the wavelength was centred at 1060.5 nm.Moreover,both the high signal to noise and long-term operation stability proved the reliability of the mode-locked laser.Furthermore,the evolution of the spatiotemporal mode-locked pulses in the cavity was also simulated and discussed.This work exhibits the flexible outputs of spatiotemporal phenomena in multimode lasers based on nanomaterials,providing more possibilities for the development of high-dimensional nonlinear dynamics.展开更多
基金National Science and Technology Council,Taiwan region,under the grant numbers MOST 109-2221-E-006-040-MY3,MOST 110-2622-E-006-001-CC1,and MOST 110-3116-F-006-003-.
文摘Torrefaction operation is an essential pathway for solid biofuel upgrading,and good hydrophobicity of torrefied biochar is conducive to its storage.Herein,a two-stage treatment of torrefaction followed by modification by hexadecyltrimethoxysilane was adopted to improve the moisture resistance performance of biochar.This two-stage treatment process led to a longer torrefied microalgal biochar preservation time(60-200%improved)and great superhydrophobicity and superlipophilicity.Therefore,the modified microalgal biochar could significantly adsorb leaking oil for environmental remediation and further improve the calorific value of the biochar.The obtained results indicated that the oil adsorption capacity of modified microalgal biochar was correlated to torrefaction temperature and oil species.Specifically,the oil adsorption capacity was enhanced up to 70-80%from the modification process when comparing to raw microalga.Increasing the torrefaction temperature enhanced the adsorption quantity of the modified microalgal biochar.By adsorbing the oil,the calorific value of oilchar,namely,biochar with adsorbed oil,could be higher than 40 MJ kg^(−1).Furthermore,the pyrolysis and combustion characteristics suggested that biochar stability gradually rose as the torrefaction temperature increased.By comprehensively analyzing and comparing the fuel performance of the modified microalgal biochar with previous literature,the obtained modified microalgal biochar possessed better fuel properties and environmental sustainability.
基金supported by the National Natural Science Foundation of China(Grant No.62071016)the State Key Laboratory of Advanced Optical Communication Systems Networks,Chinathe Academic Excellence Foundation of BUAA for PhD Students.
文摘We investigated 1-μm multimode fiber laser based on carbon nanotubes,where multiple typical pulse states were observed,including Q-switched,Q-switched mode-locked,and spatiotemporal mode-locked pulses.Particularly,stable spatiotemporal mode-locking was realized with a low threshold,where the pulse duration was 37 ps and the wavelength was centred at 1060.5 nm.Moreover,both the high signal to noise and long-term operation stability proved the reliability of the mode-locked laser.Furthermore,the evolution of the spatiotemporal mode-locked pulses in the cavity was also simulated and discussed.This work exhibits the flexible outputs of spatiotemporal phenomena in multimode lasers based on nanomaterials,providing more possibilities for the development of high-dimensional nonlinear dynamics.
