Flotation indexes gradually decrease with the increase of cycle time of the backwater in bauxite floatation,and discharge of backwater brings environmental risk.In this study,methods such as Fenton-oxidation,adsorptio...Flotation indexes gradually decrease with the increase of cycle time of the backwater in bauxite floatation,and discharge of backwater brings environmental risk.In this study,methods such as Fenton-oxidation,adsorption and coagulation were used in the treatment of backwater,the flotation indexes were checked after backwater treatments,and Box-Behnken design(BBD)was used in the optimization of the main operating parameters.The results reveal that flotation indexes are effectively improved after coagulation treatment by polyaluminum ferric chloride(PAFC).The optimum parameters predicted by BBD are pH 7.55,1.09 g/L PAFC dosage and temperature of 25℃.Under these optimum conditions,a maximum recovery of Al2O3 of 82.83%and a minimum A/S of 1.30 of tailings are gained,while the deviations are less than 3%from the predicted values.These findings encourage the application of BBD for the optimization of critical parameters in backwater treatment.展开更多
The photovoltaic(PV)market is currently dominated by silicon based solar cells.However technological diversification is essential to promote competition,which is the driving force for technological growth.Historically...The photovoltaic(PV)market is currently dominated by silicon based solar cells.However technological diversification is essential to promote competition,which is the driving force for technological growth.Historically,the choice of PV materials has been limited to the three-dimensional(3D)compounds with a high crystal symmetry and direct band gap.However,to meet the strict demands for sustainable PV applications,material space has been expanded beyond 3D compounds.In this perspective we discuss the potential of low-dimensional materials(2D,1D)for application in PVs.We present unique features of low-dimensional materials in context of their suitability in the solar cells.The band gap,absorption,carrier dynamics,mobility,defects,surface states and growth kinetics are discussed and compared to 3D counterparts,providing a comprehensive view of prospects of low-dimensional materials.Structural dimensionality leads to a highly anisotropic carrier transport,complex defect chemistry and peculiar growth dynamics.By providing fundamental insights into these challenges we aim to deepen the understanding of low-dimensional materials and expand the scope of their application.Finally,we discuss the current research status and development trend of solar cell devices made of low-dimensional materials.展开更多
The random fiber laser(RFL)has been an excellent platform for exploring novel optical dynamics and developing new functional optoelectronic devices.However,it is challenging for RFLs to regulate their emission into re...The random fiber laser(RFL)has been an excellent platform for exploring novel optical dynamics and developing new functional optoelectronic devices.However,it is challenging for RFLs to regulate their emission into regular narrow pulses due to their intrinsic randomness.Here,through engineering the laser configuration(cavity Q value,gain distribution and nonlinearity),we demonstrate that narrow(~2.5 ns)pulses with record peak power as high as 64.3 kW are achieved from a self-Q-switched random ytterbium fiber laser.Based on high intracavity intensity and efficient interplay of multiple nonlinear processes(stimulated Brillouin scattering,stimulated Raman scattering and four-wave mixing),an over-one-octave visible-near-infrared(NIR)Raman-frequency comb is generated from single-mode silica fibers for the first time.After spectrally filtering the Raman peaks,wavelength-tunable pulses with durations of several hundreds of picoseconds are obtained.Such a high-peak-power random Q-switched fiber laser and wide frequency comb in the visible-NIR region can find applications in diverse areas,such as spectroscopy,biomedical imaging and quantum information.展开更多
Wide-bandgap(WB)mixed-halide perovskite solar cells(PSCs)play a crucial role in perovskite-based tandem solar cells(TSCs),enabling them to exceed the Shockley-Queisser limits of single-junction solar cells.Nonetheless...Wide-bandgap(WB)mixed-halide perovskite solar cells(PSCs)play a crucial role in perovskite-based tandem solar cells(TSCs),enabling them to exceed the Shockley-Queisser limits of single-junction solar cells.Nonetheless,the lack of stability in WB perovskite films due to photoinduced phase segregation undermines the stability of WB PSCs and their TSCs,thus impeding the commercialization of perovskite-based TSCs.Many efforts have been made to suppress photoinduced phase segregation in WB perovskite films and significant progresses have been obtained.In this review,we elaborate the mechanisms behind photoinduced phase segregation and its impact on the photovoltaic performance and stability of devices.The importance role of advanced characterization techniques in confirming the photoinduced phase segregation are comprehensively summarized.Beyond that,the effective strategies to alleviate photoinduced phase segregation in WB mixed halide PSCs are systematically assessed.Finally,the prospects for developing highly efficient and stable WB PSCs in tandem application are also presented.展开更多
基金Project(1053320170205)supported by the Research and Innovation Project of Graduate Students of Central South University,ChinaProject(502211704)supported by the Fundamental Research Funds for the Central Universities,China+3 种基金Project(SKL-SPM-201809)supported by the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals,ChinaProject(SKLAM005-2016)supported by the State Key Laboratory of Applied Microbiology Southern ChinaProjects(51320105006,51504106,51871250)supported by the National Natural Science Foundation of ChinaProject(2015FB204)supported by the Science and Technology Project of Yunnan Province,China
文摘Flotation indexes gradually decrease with the increase of cycle time of the backwater in bauxite floatation,and discharge of backwater brings environmental risk.In this study,methods such as Fenton-oxidation,adsorption and coagulation were used in the treatment of backwater,the flotation indexes were checked after backwater treatments,and Box-Behnken design(BBD)was used in the optimization of the main operating parameters.The results reveal that flotation indexes are effectively improved after coagulation treatment by polyaluminum ferric chloride(PAFC).The optimum parameters predicted by BBD are pH 7.55,1.09 g/L PAFC dosage and temperature of 25℃.Under these optimum conditions,a maximum recovery of Al2O3 of 82.83%and a minimum A/S of 1.30 of tailings are gained,while the deviations are less than 3%from the predicted values.These findings encourage the application of BBD for the optimization of critical parameters in backwater treatment.
基金supported by the National Natural Science Foundation of China(61725401,61904058,61904058)the National Key R&D Program of China(2016YFA0204000)+1 种基金China Postdoctoral Science Foundation Project(2019M662623)the National Postdoctoral Program for Innovative Talent(BX20190127).
文摘The photovoltaic(PV)market is currently dominated by silicon based solar cells.However technological diversification is essential to promote competition,which is the driving force for technological growth.Historically,the choice of PV materials has been limited to the three-dimensional(3D)compounds with a high crystal symmetry and direct band gap.However,to meet the strict demands for sustainable PV applications,material space has been expanded beyond 3D compounds.In this perspective we discuss the potential of low-dimensional materials(2D,1D)for application in PVs.We present unique features of low-dimensional materials in context of their suitability in the solar cells.The band gap,absorption,carrier dynamics,mobility,defects,surface states and growth kinetics are discussed and compared to 3D counterparts,providing a comprehensive view of prospects of low-dimensional materials.Structural dimensionality leads to a highly anisotropic carrier transport,complex defect chemistry and peculiar growth dynamics.By providing fundamental insights into these challenges we aim to deepen the understanding of low-dimensional materials and expand the scope of their application.Finally,we discuss the current research status and development trend of solar cell devices made of low-dimensional materials.
基金The Project of Hebei North University(Grant No.XJ2023041)the Natural Science Foundation of Hebei Province(Grant No.H2021405021)the S&T Program of Hebei(Grant No.V1623922326576)。
基金supported by the National Natural Science Foundation of China(No.61675129)the Natural Science Foundation of Shanghai(No.19ZR1427100)
文摘The random fiber laser(RFL)has been an excellent platform for exploring novel optical dynamics and developing new functional optoelectronic devices.However,it is challenging for RFLs to regulate their emission into regular narrow pulses due to their intrinsic randomness.Here,through engineering the laser configuration(cavity Q value,gain distribution and nonlinearity),we demonstrate that narrow(~2.5 ns)pulses with record peak power as high as 64.3 kW are achieved from a self-Q-switched random ytterbium fiber laser.Based on high intracavity intensity and efficient interplay of multiple nonlinear processes(stimulated Brillouin scattering,stimulated Raman scattering and four-wave mixing),an over-one-octave visible-near-infrared(NIR)Raman-frequency comb is generated from single-mode silica fibers for the first time.After spectrally filtering the Raman peaks,wavelength-tunable pulses with durations of several hundreds of picoseconds are obtained.Such a high-peak-power random Q-switched fiber laser and wide frequency comb in the visible-NIR region can find applications in diverse areas,such as spectroscopy,biomedical imaging and quantum information.
基金the National Natural Science Foundation of China(Grant No.62274018)the Xinjiang Construction Corps Key Areas of Science and Technology Research Project(Grant No.2023AB029)the Key Project of Chongqing Overseas Students Returning to China Entrepreneurship and Innovation Support Plan(Grant No.cx2023006).
文摘Wide-bandgap(WB)mixed-halide perovskite solar cells(PSCs)play a crucial role in perovskite-based tandem solar cells(TSCs),enabling them to exceed the Shockley-Queisser limits of single-junction solar cells.Nonetheless,the lack of stability in WB perovskite films due to photoinduced phase segregation undermines the stability of WB PSCs and their TSCs,thus impeding the commercialization of perovskite-based TSCs.Many efforts have been made to suppress photoinduced phase segregation in WB perovskite films and significant progresses have been obtained.In this review,we elaborate the mechanisms behind photoinduced phase segregation and its impact on the photovoltaic performance and stability of devices.The importance role of advanced characterization techniques in confirming the photoinduced phase segregation are comprehensively summarized.Beyond that,the effective strategies to alleviate photoinduced phase segregation in WB mixed halide PSCs are systematically assessed.Finally,the prospects for developing highly efficient and stable WB PSCs in tandem application are also presented.
