Air pollution is fourth major cause of death worldwide.Recent evidence suggests that particulate matter(PM)may affect kidneys,and the effect may be size and composition dependent.In this study,PM_(0.1),PM_(2.5),and PM...Air pollution is fourth major cause of death worldwide.Recent evidence suggests that particulate matter(PM)may affect kidneys,and the effect may be size and composition dependent.In this study,PM_(0.1),PM_(2.5),and PM_(10)were collected from ambient air and given to BALB/c male mice at 0.25 mg/m^(3) concentration in whole-body inhalation chamber for 28days(6 h/day,5 days/week)to assess their effect on kidney.Physico-chemical characterization of PM particles by SEM,ICP-MS and HPLC showed their various shapes along with the presence of metals and poly aromatic hydrocarbons(PAHs).Following PM exposure,increased serum creatinine levels were observed in animals along with dilated tubules,protein cast deposition,necrosis,immune infiltration,collagen deposition,and shrunken glomeruli in kidney.Immunofluorescence staining showed higher expressions of kidney injury molecule1(KIM-1),cystatin C,β2 microglobulin(β2M),and alpha smooth muscle actin(α-SMA)and fibronectin,suggesting renal injury and fibrosis.PM exposure also increased malondialdehyde(MDA)content and decreased superoxide dismutase 2(SOD2)activity,which in turn leads to induction of inflammation.Mechanistically,PM exposure further inhibited the nuclear factor erythroid 2-related factor 2(Nrf2)signalling and induced kelch-like ECH-associated protein 1(Keap1)and nuclear factor kappa-light-chain-enhancer of activated B(NF-κB).Interestingly,the effect of PM_(2.5)was more severe than PM_(0.1)and PM_(10),leading to higher levels of proinflammatory NF-κB and greater Nrf2 inhibition.Overall,our findings suggested that inhalation exposure to size-segregated PM can cause kidney damage and fibrosis,and PM_(2.5)showed higher toxicity than PM_(0.1)and PM_(10).展开更多
Aggregates of cerium dioxide nanoparticles(nano-CeO_2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO_2 were syst...Aggregates of cerium dioxide nanoparticles(nano-CeO_2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO_2 were systematically studied by X-ray diffraction(XRD),transmission electron microscopy(TEM), laser particle size analyzer(LA) and specific surface area and pore size analyzer during the solvothermal process. Among all the obtained samples, the 18-h solvothermal-prepared nano-CeO_2 aggregates show the best crystallinity and the largest specific surface area of 110.92 m^2·g^(-1). Owing to the high activity derived from the high specific surface area of the aggregates, the application as arsenic(As) adsorption was also studied. The adsorption efficiency of arsenic by nano-CeO_2 aggregates was established as the function of adsorbent dose, then pH value and at last adsorption time.The results indicate that the nano-CeO_2 aggregates show a high efficiency in removing arsenic from low As concentration solution, from which the nano-CeO_2 adsorbent could be easily separated. In addition, the adsorption kinetics is best fitted to pseudo-second-order model(R^2 = 0.99999).展开更多
Nano-Y2O3 and nano-CeO2 of different weight ratio mixed with deionizing water were doped into MoO2 powder by liquid-solid doping method. The diameter 1.80 and 0.18 mm alloy wires of Mo-0.3Y, Mo-0.3Ce, and Mo-0.15Y-0.1...Nano-Y2O3 and nano-CeO2 of different weight ratio mixed with deionizing water were doped into MoO2 powder by liquid-solid doping method. The diameter 1.80 and 0.18 mm alloy wires of Mo-0.3Y, Mo-0.3Ce, and Mo-0.15Y-0.15Ce were prepared through reduction, iso- static pressing, sintering, and drawing. Tensile properties, second phase microstructure and fracture surface appear- ance of wires were analyzed. The better refining effect for Mo alloy powder can be gotten after two kinds of nano- particle oxide doped into MoO2 than only one doped. Nano-Y2O3 and nano-CeO2 have different influences on sintering process. For nano-CeO2, the constraining effect of grain growth focuses on the initial sintering stage, nano- Y2O3 plays refining grains roles in the later densification stage. Nano-Y2O3 is undistorted and keeps intact in the process of drawing; and nano-CeO2 is elongated and bro- ken into parts in the drawing direction. The strengthening effect of nano-Y2O3 and nano-CeO2 keeps the finer grains and superior tensile properties for Mo-0.15Y-0.15Ce wire.展开更多
γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM） techniques. At the same time, the des...γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM） techniques. At the same time, the desulfurization activity of catalysts was investigated. The results show that nanoscale active substances and a high desulfurization effect are achieved by microemulsion, exhibiting a significant dominance compared with traditional impregnation method. The optimal preparation condition is temperature of 30 ℃ and ratio of [H20]/[surface active agent] of 7 with slow demulsification. The activated catalysts still keep high and stable desulfurization activity during a wide temperature range of 450-600 ℃. Among a series of prepared catalysts, the desulfurization rate of 6CeOz/γ-A1203 is the highest, reaching up to 80 % when temperature is higher than 550℃. The catalytic reduction mechanism of SO2 over nano-CeOz/γ-A1203 follows redox mechanism.展开更多
In this study,three kinds of A380/Al2O3 composite coatings were prepared by cold spray(CS)using spherical,irregular and spherical+irregular shaped Al2O3 particulates separately mixed in the original A380 alloy powders...In this study,three kinds of A380/Al2O3 composite coatings were prepared by cold spray(CS)using spherical,irregular and spherical+irregular shaped Al2O3 particulates separately mixed in the original A380 alloy powders.The influence of Al2O3 particulates’morphology on the microstructural characteristics(i.e.retention of Al2O3 content in coatings,coating/matrix interfacial bonding,pore size distribution and morphology etc.)and wear performance of the coatings was investigated by scanning electron microscopy(SEM),X-ray computed tomography(XCT)and 3-D optical profilometry.Results indicated that the spherical Al2O3 showsobvious tamping effect during deposition process.As a result,the interfaceshowedawavy shape while the matrix and particulates were mechanical interlocked with much improved adhesion.In addition,the porosity of the coating was minimized and the pores exhibited curved spherical structure with reduced dimensions.The irregular Al2O3 particles predominantly displayed the embedding effect together with fragmentation of Al2O3 particulates.Consequently,poor coating/matrix interfacial bonding,high porosity and the formation of angular-shaped pores were resulted in the coating.Dry sliding wear tests results revealed that the wear resistance of the coating is directly related with the retained content of Al2O3 in the coating.The coating containing irregular Al2O3 particulates displayed superior wear performance with its wear rate one seventh of that of the pure A380 alloy coating.The coating containing both kinds of Al2O3 particulates showed mixed characteristics of above two kinds of Al2O3 composite coatings.展开更多
A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes(E-wastes), including printed wiring boards(PWBs)and plastic casings. The generated particula...A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes(E-wastes), including printed wiring boards(PWBs)and plastic casings. The generated particulate matter(PM) of different particle sizes, carbon monoxide(CO) and carbon dioxide(CO_2) were determined, and the corresponding emission factors(EFs) were estimated. Finer particles with particle sizes of 0.4–2.1 μm accounted for78.9% and 89.3% of PM emitted by the pyrolytic processing of PWBs and plastic casings,respectively, and the corresponding EFs were 9.68 ± 4.81 and 18.49 ± 7.2 g/kg, respectively.The EFs of CO and CO_2 from PWBs and plastic casings were 55.9 ± 26.9 and 1182 ± 439 g/kg,and 133.6 ± 34.6 and 2827 ± 276 g/kg, respectively. Compared with other emission sources,such as coal, biomass, and traffic exhaust, the EFs of E-wastes were relatively higher,especially for PM. There were significant positive correlations(p < 0.05) of the initial contents of carbon and nitrogen in PWBs with the related EFs of PM, CO, and CO_2, while the correlations for plastic casings were insignificant. The EFs of CO of PWBs were significantly positively correlated with the corresponding EFs of PM and the parent polycyclic aromatic hydrocarbons(PAHs); however, the same result was not observed for plastic casings.展开更多
With the objective to investigate the structure-reactivity relationship of CuO/SnO2 and eventually design more applicable catalysts for soot combustion,catalysts with different CuO loadings have been prepared by impre...With the objective to investigate the structure-reactivity relationship of CuO/SnO2 and eventually design more applicable catalysts for soot combustion,catalysts with different CuO loadings have been prepared by impregnation method.By using X-ray diffraction and X-ray photoelectron spectroscopy extrapolation methods,it is disclosed that CuO disperses finely on the SnO2 support to form a monolayer with a capacity of 2.09 mmol 100 m^-2,which equals 4.8 wt%CuO loading.When the CuO loading is below the capacity,it is in a sub-monolayer state.However,when the loading is above the capacity,CuO micro-crystallites will be formed that coexist with the CuO monolayer.The soot combustion activity of the catalyst increases with the CuO loading until it reaches the monolayer dispersion capacity.A further increase in the CuO loading has no evident influence on the activity.Raman results have testified that with the addition of CuO onto the SnO2 support,a surface-active oxygen species can be formed,the amount of which also increases significantly with the increase in the CuO loading until it reaches the monolayer dispersion capacity.Increasing the CuO loading further has no evident impact on the amount of surface oxygen.Therefore,an apparent monolayer dispersion threshold effect is observed for soot combustion over CuO/SnO2 catalysts.It is concluded that the amount of surface-active oxygen sites is the major factor determining the activity of the catalyst.展开更多
An in situ reaction and spray forming technique were employed in the synthesis of 2% TiB2/Si-30Al composite.The formation mechanism of TiB2 particulates was explained based on thermodynamic theory.The modification of ...An in situ reaction and spray forming technique were employed in the synthesis of 2% TiB2/Si-30Al composite.The formation mechanism of TiB2 particulates was explained based on thermodynamic theory.The modification of the primary Si in the Si-30Al alloy was interpreted in the light of the knowledge of atomic diffusion.The experimental results show that adding 2% TiB2 to the Si-30Al alloy can effectively refine the primary Si.Moreover,the coarsening and growth of primary Si phase in its semi-solid state was retarded effectively due to the existence of the TiB2 particulates.展开更多
基金supported by the institutional fund MLP004 and Science and Engineering Research Board(SERB)(No.CRG/2021/002625)financial assistance from DBT-JRF,Department of Biotechnology,Gov of India,New Delhi India(DBT/2018/1111)。
文摘Air pollution is fourth major cause of death worldwide.Recent evidence suggests that particulate matter(PM)may affect kidneys,and the effect may be size and composition dependent.In this study,PM_(0.1),PM_(2.5),and PM_(10)were collected from ambient air and given to BALB/c male mice at 0.25 mg/m^(3) concentration in whole-body inhalation chamber for 28days(6 h/day,5 days/week)to assess their effect on kidney.Physico-chemical characterization of PM particles by SEM,ICP-MS and HPLC showed their various shapes along with the presence of metals and poly aromatic hydrocarbons(PAHs).Following PM exposure,increased serum creatinine levels were observed in animals along with dilated tubules,protein cast deposition,necrosis,immune infiltration,collagen deposition,and shrunken glomeruli in kidney.Immunofluorescence staining showed higher expressions of kidney injury molecule1(KIM-1),cystatin C,β2 microglobulin(β2M),and alpha smooth muscle actin(α-SMA)and fibronectin,suggesting renal injury and fibrosis.PM exposure also increased malondialdehyde(MDA)content and decreased superoxide dismutase 2(SOD2)activity,which in turn leads to induction of inflammation.Mechanistically,PM exposure further inhibited the nuclear factor erythroid 2-related factor 2(Nrf2)signalling and induced kelch-like ECH-associated protein 1(Keap1)and nuclear factor kappa-light-chain-enhancer of activated B(NF-κB).Interestingly,the effect of PM_(2.5)was more severe than PM_(0.1)and PM_(10),leading to higher levels of proinflammatory NF-κB and greater Nrf2 inhibition.Overall,our findings suggested that inhalation exposure to size-segregated PM can cause kidney damage and fibrosis,and PM_(2.5)showed higher toxicity than PM_(0.1)and PM_(10).
基金financially supported by the Sichuan Province Science and Technology Support Program (No. 2014GZ0090)
文摘Aggregates of cerium dioxide nanoparticles(nano-CeO_2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-CeO_2 were systematically studied by X-ray diffraction(XRD),transmission electron microscopy(TEM), laser particle size analyzer(LA) and specific surface area and pore size analyzer during the solvothermal process. Among all the obtained samples, the 18-h solvothermal-prepared nano-CeO_2 aggregates show the best crystallinity and the largest specific surface area of 110.92 m^2·g^(-1). Owing to the high activity derived from the high specific surface area of the aggregates, the application as arsenic(As) adsorption was also studied. The adsorption efficiency of arsenic by nano-CeO_2 aggregates was established as the function of adsorbent dose, then pH value and at last adsorption time.The results indicate that the nano-CeO_2 aggregates show a high efficiency in removing arsenic from low As concentration solution, from which the nano-CeO_2 adsorbent could be easily separated. In addition, the adsorption kinetics is best fitted to pseudo-second-order model(R^2 = 0.99999).
基金financially supported by the National Tungsten and Molybdenum Value-added Utilization Tech-nology Industry Development(No.2012BAE06B02)Shanxi Province Science and Technology Innovation Plan(No.2012KTCQ01-08)
文摘Nano-Y2O3 and nano-CeO2 of different weight ratio mixed with deionizing water were doped into MoO2 powder by liquid-solid doping method. The diameter 1.80 and 0.18 mm alloy wires of Mo-0.3Y, Mo-0.3Ce, and Mo-0.15Y-0.15Ce were prepared through reduction, iso- static pressing, sintering, and drawing. Tensile properties, second phase microstructure and fracture surface appear- ance of wires were analyzed. The better refining effect for Mo alloy powder can be gotten after two kinds of nano- particle oxide doped into MoO2 than only one doped. Nano-Y2O3 and nano-CeO2 have different influences on sintering process. For nano-CeO2, the constraining effect of grain growth focuses on the initial sintering stage, nano- Y2O3 plays refining grains roles in the later densification stage. Nano-Y2O3 is undistorted and keeps intact in the process of drawing; and nano-CeO2 is elongated and bro- ken into parts in the drawing direction. The strengthening effect of nano-Y2O3 and nano-CeO2 keeps the finer grains and superior tensile properties for Mo-0.15Y-0.15Ce wire.
基金financially supported by the Natural Science Foundation of Hubei Province, China(No. 2009CDB246)the Applied Basic Research Project of Wuhan City (No. 2015060101010068)
文摘γ-A12O3-supported CeO2 catalysts were pre- pared by microemulsion and impregnation methods and characterized by X-ray diffraction （XRD） and scanning electron microscope （SEM） techniques. At the same time, the desulfurization activity of catalysts was investigated. The results show that nanoscale active substances and a high desulfurization effect are achieved by microemulsion, exhibiting a significant dominance compared with traditional impregnation method. The optimal preparation condition is temperature of 30 ℃ and ratio of [H20]/[surface active agent] of 7 with slow demulsification. The activated catalysts still keep high and stable desulfurization activity during a wide temperature range of 450-600 ℃. Among a series of prepared catalysts, the desulfurization rate of 6CeOz/γ-A1203 is the highest, reaching up to 80 % when temperature is higher than 550℃. The catalytic reduction mechanism of SO2 over nano-CeOz/γ-A1203 follows redox mechanism.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51671205 and 51801217).
文摘In this study,three kinds of A380/Al2O3 composite coatings were prepared by cold spray(CS)using spherical,irregular and spherical+irregular shaped Al2O3 particulates separately mixed in the original A380 alloy powders.The influence of Al2O3 particulates’morphology on the microstructural characteristics(i.e.retention of Al2O3 content in coatings,coating/matrix interfacial bonding,pore size distribution and morphology etc.)and wear performance of the coatings was investigated by scanning electron microscopy(SEM),X-ray computed tomography(XCT)and 3-D optical profilometry.Results indicated that the spherical Al2O3 showsobvious tamping effect during deposition process.As a result,the interfaceshowedawavy shape while the matrix and particulates were mechanical interlocked with much improved adhesion.In addition,the porosity of the coating was minimized and the pores exhibited curved spherical structure with reduced dimensions.The irregular Al2O3 particles predominantly displayed the embedding effect together with fragmentation of Al2O3 particulates.Consequently,poor coating/matrix interfacial bonding,high porosity and the formation of angular-shaped pores were resulted in the coating.Dry sliding wear tests results revealed that the wear resistance of the coating is directly related with the retained content of Al2O3 in the coating.The coating containing irregular Al2O3 particulates displayed superior wear performance with its wear rate one seventh of that of the pure A380 alloy coating.The coating containing both kinds of Al2O3 particulates showed mixed characteristics of above two kinds of Al2O3 composite coatings.
基金supported by the Natural Science Foundation Committee of China(No.41390240)the National Basic Research Program of China(No.2014CB441101)
文摘A self-designed experimental device was employed to simulate the pyrolytic dismantling process of selected electronic wastes(E-wastes), including printed wiring boards(PWBs)and plastic casings. The generated particulate matter(PM) of different particle sizes, carbon monoxide(CO) and carbon dioxide(CO_2) were determined, and the corresponding emission factors(EFs) were estimated. Finer particles with particle sizes of 0.4–2.1 μm accounted for78.9% and 89.3% of PM emitted by the pyrolytic processing of PWBs and plastic casings,respectively, and the corresponding EFs were 9.68 ± 4.81 and 18.49 ± 7.2 g/kg, respectively.The EFs of CO and CO_2 from PWBs and plastic casings were 55.9 ± 26.9 and 1182 ± 439 g/kg,and 133.6 ± 34.6 and 2827 ± 276 g/kg, respectively. Compared with other emission sources,such as coal, biomass, and traffic exhaust, the EFs of E-wastes were relatively higher,especially for PM. There were significant positive correlations(p < 0.05) of the initial contents of carbon and nitrogen in PWBs with the related EFs of PM, CO, and CO_2, while the correlations for plastic casings were insignificant. The EFs of CO of PWBs were significantly positively correlated with the corresponding EFs of PM and the parent polycyclic aromatic hydrocarbons(PAHs); however, the same result was not observed for plastic casings.
基金supported by the National Natural Science Foundation of China(21567016,21666020)the Natural Science Foundation of Jiangxi Province(20181ACB20005,20171BAB213013,20181BCD40004,20181BAB203017)+2 种基金the Innovation Fund Designated for Graduate Students of Jiangxi Province(YC2018-B015)the Education Department Foundation of Jiangxi Province(KJLD14005)the Opening Fund of Key Laboratory of Process Analysis and Control of Sichuan Universities(2017002)~~
文摘With the objective to investigate the structure-reactivity relationship of CuO/SnO2 and eventually design more applicable catalysts for soot combustion,catalysts with different CuO loadings have been prepared by impregnation method.By using X-ray diffraction and X-ray photoelectron spectroscopy extrapolation methods,it is disclosed that CuO disperses finely on the SnO2 support to form a monolayer with a capacity of 2.09 mmol 100 m^-2,which equals 4.8 wt%CuO loading.When the CuO loading is below the capacity,it is in a sub-monolayer state.However,when the loading is above the capacity,CuO micro-crystallites will be formed that coexist with the CuO monolayer.The soot combustion activity of the catalyst increases with the CuO loading until it reaches the monolayer dispersion capacity.A further increase in the CuO loading has no evident influence on the activity.Raman results have testified that with the addition of CuO onto the SnO2 support,a surface-active oxygen species can be formed,the amount of which also increases significantly with the increase in the CuO loading until it reaches the monolayer dispersion capacity.Increasing the CuO loading further has no evident impact on the amount of surface oxygen.Therefore,an apparent monolayer dispersion threshold effect is observed for soot combustion over CuO/SnO2 catalysts.It is concluded that the amount of surface-active oxygen sites is the major factor determining the activity of the catalyst.
基金Project(707007)supported by the Cultivation Fund of the Key Scientific and Technical Innovation,ChinaProject(2093040)supported by Beijing Municipal Natural Science Foundation,China
文摘An in situ reaction and spray forming technique were employed in the synthesis of 2% TiB2/Si-30Al composite.The formation mechanism of TiB2 particulates was explained based on thermodynamic theory.The modification of the primary Si in the Si-30Al alloy was interpreted in the light of the knowledge of atomic diffusion.The experimental results show that adding 2% TiB2 to the Si-30Al alloy can effectively refine the primary Si.Moreover,the coarsening and growth of primary Si phase in its semi-solid state was retarded effectively due to the existence of the TiB2 particulates.
