The use of water resources for energy generation has become increasingly prevalent,encompassing the conversion of kinetic energy from streams,tides,and waves into renewable electrical power.Water energy sources offer ...The use of water resources for energy generation has become increasingly prevalent,encompassing the conversion of kinetic energy from streams,tides,and waves into renewable electrical power.Water energy sources offer numerous benefits,including widespread availability,stability,and the absence of carbon dioxide and other greenhouse gas emissions,making them a clean and environmentally friendly form of energy.In this work,we develop a droplet-based liquid-solid triboelectric nanogenerator(LS-TENG)using sophisticatedly designed inflatable columnar structures with inner and outer dual-electrodes.This device can be utilized to harvest both the internal droplet-rolling mechanical energy and the external droplet-falling mechanical energy,capable of being assembled into various structures for versatile applications.The design incorporates a combined structure of both internal and external TENG to optimize output performance via multiple energy harvesting strategies.The internal structure features a dual-electrode columnar-shaped LS-TENG,designed to harvest fluid kinetic energy from water droplets.By leveraging the back-and-forth motion of a small amount of water within the air column,mechanical energy can be readily collected,achieving a maximum mass power density of 9.02 W·Kg^(−1)and an energy conversion efficiency of 10.358%.The external component is a droplet-based LS-TENG,which utilizes a double-layer capacitor switch effect elucidated with an equivalent circuit model.Remarkably,without the need for pre-charging,a single droplet can generate over 140 V of high voltage,achieving a maximum power density of 7.35 W·m^(−2)and an energy conversion efficiency of 22.058%.The combined LS-TENG with a sophisticated inflatable columnar structure can simultaneously collect multiple types of energy with high efficacy,exhibiting great significance in potential applications such as TENG aeration rollers,inflatable lifejacket,wind energy harvesting,TENG tents,and green houses.展开更多
Various manganese oxides(MnOx) prepared via citric acid solution combustion synthesis were applied for catalytic oxidation of benzene. The results showed the ratios of citric acid/manganese nitrate in synthesizing pro...Various manganese oxides(MnOx) prepared via citric acid solution combustion synthesis were applied for catalytic oxidation of benzene. The results showed the ratios of citric acid/manganese nitrate in synthesizing process positively affected the physicochemical properties of MnOx, e.g., BET(Brunauer-Emmett-Teller) surface area, porous structure, reducibility and so on, which were in close relationship with their catalytic performance. Of all the catalysts, the sample prepared at a citric acid/manganese nitrate ratio of 2:1(C2M1) displayed the best catalytic activity with T(90)(the temperature when 90% of benzene was catalytically oxidized) of 212 ℃. Further investigation showed that C2M1 was Mn2O3 with abundant nano-pores, the largest surface area and the proper ratio of surface Mn^4+/Mn^3+, resulting in preferable low-temperature reducibility and abundant surface active adsorbed oxygen species. The analysis results of the in-situ Fourier transform infrared spectroscopy(in-situ FTIR) revealed that the benzene was successively oxidized to phenolate, o-benzoquinone, small molecules(such as maleates, acetates, and vinyl), and finally transformed to CO2 and H2O.展开更多
Pt supported on mesoporous silica SBA-15 was investigated as a catalyst for low temperature selective catalytic reduction（SCR） of NO by C 3 H 6 in the presence of excess oxygen.The prepared catalysts were characteri...Pt supported on mesoporous silica SBA-15 was investigated as a catalyst for low temperature selective catalytic reduction（SCR） of NO by C 3 H 6 in the presence of excess oxygen.The prepared catalysts were characterized by means of XRD,BET surface area,TEM,NO-TPD,NO/C 3 H 6-TPO,NH 3-TPD,XPS and 27 Al MAS NMR.The effects of Pt loading amount,O 2 /C 3 H 6 concentration,and incorporation of Al into SBA-15 have been studied.It was found that the removal efficiency increased significantly after Pt loading,but an optimal loading amount was observed.In particular,under an atmosphere of 150 ppm NO,150 ppm C 3 H 6,and 18 vol.% O 2,0.5% Pt/SBA-15 showed remarkably high catalytic performance giving 80.1% NOx reduction and 87.04% C 3 H 6 conversion simultaneously at 140°C.The enhanced SCR activity of Pt/SBA-15 is associated with its outstanding oxidation activities of NO to NO 2 and C 3 H 6 to CO 2 in low temperature range.The research results also suggested that higher concentration of O 2 and higher concentration of C 3 H 6 favored NO removal.The incorporation of Al into SBA-15 improved catalytic performance,which could be ascribed to the enhancement of catalyst surface acidity caused by tetrahedrally coordinated AlO 4.Moreover,the catalysts could be easily reused and possessed good stability.展开更多
A 0.5 wt.%Pt/TiO_(2)catalyst was prepared and used for the low-temperature selective catalytic reduction(SCR)of NO with C3H6 in the presence of excess oxygen.The effects of Pt loading and 02 concentration on Pt/TiO_(2...A 0.5 wt.%Pt/TiO_(2)catalyst was prepared and used for the low-temperature selective catalytic reduction(SCR)of NO with C3H6 in the presence of excess oxygen.The effects of Pt loading and 02 concentration on Pt/TiO_(2)catalytic performance for low-temperature SCR were investigated.It was found that optimal Pt loading was 0.5 wt.%and excess 02 favored low-temperature SCR of NOx.The mechanism of low-temperature SCR of NO with C3H6 was investigated with respect to the behavior of adsorbed species over Pt/TiO_(2)at 150~C using in situ DRIFTS.The results indicated that surface nitrosyl species(Pt~+-NO and Ti3+-NO)and pt2+-CO are main reaction intermediates during the interactions of NO,C3H6 and 02.A simplified NO decomposition mechanism for the low-temperature SCR of NO with C3H6 was proposed.展开更多
TiO2-WO3 hybrid photocatalysts were prepared using wet-chemical technique,and their energy storage performance was characterized by electrochemical galvanostatic method.TiO2 powder was coupled with WO3 powder,which wa...TiO2-WO3 hybrid photocatalysts were prepared using wet-chemical technique,and their energy storage performance was characterized by electrochemical galvanostatic method.TiO2 powder was coupled with WO3 powder,which was used as electron pool and the reductive energy could be stored in.As a result,the prepared TiO2-WO3 had good energy storage ability while pure TiO2 showed no capacity and pure WO3 showed quite low performance.The energy storage ability was affected by the crystal structure of WO3 and calcination temperature.The photocatalyst had better capacity when WO3 had low degree of crystallinity,since its loose structure made it easier for electrons and cations to pass through.The photocatalytic energy storage performance was also affected by the molar ratio of TiO2 to WO3.Energy storage capacity was significantly dependent on the composition,reaching the maximum value at TiO2/WO31:1(mol/mol).展开更多
Inhalable particle is a harmful air pollutant that causes a significant threat to people's health and ecological environments,which should be removed to purify air,but there exists limited removal efficiency due t...Inhalable particle is a harmful air pollutant that causes a significant threat to people's health and ecological environments,which should be removed to purify air,but there exists limited removal efficiency due to particle re-entrainment.Here,Operando observation system based on microscopic visualization method is developed to make in situ test of particle migration,deposition and re-entrainment characteristics on a lab-on-a-chip to achieve the investigation in micro-level scale.The deposition evolution of charged particles is recorded in electric field region intuitively,which confirms the fracture of particle chain occurs during the growth process of deposited particles.It captures the instantaneous process that a larger particle with micron size due to the coagulation of submicron particles fractures from main body of the particle chain for the first time.The analysis of migration behavior of a single submicron particle near electrode surface demonstrates the direct influence of drag force on the fracture of particle chain.This work is the first-time visualization of dynamic process and mechanism elucidation of particle re-entrainment at the micron level,and the findings will provide the theory support for the particle re-entrainment mechanism and bring inspires of enhancing capture efficiency of inhalable particle.展开更多
Novel CdS and Bi2S3 hollow nanospheres were prepared by simple “one-pot” biomolecule-assisted hydrothermal method using glutathione (GSH) as sulfur source and structure-directing reagents. The single-phase CdS and B...Novel CdS and Bi2S3 hollow nanospheres were prepared by simple “one-pot” biomolecule-assisted hydrothermal method using glutathione (GSH) as sulfur source and structure-directing reagents. The single-phase CdS and Bi2S3 photocatalysts were capable of evolving H2 from aqueous solutions containing a sacrificial electron donor, under visible light irradiation (λ ≥ 420 nm) with Pt co-catalyst. A possible formation mechanism of complexation, S-C bond rupture, and spherical aggregate followed isotropic Ostwal ripening or anisotropic Ostwal ripening was proposed in this study.展开更多
Plasma-coupled catalysis is a promising volatile organic co mpounds(VOCs) removal technology because of its interactional principles of plasma decomposition and catalytic oxidation.However,the problem of harmful by-pr...Plasma-coupled catalysis is a promising volatile organic co mpounds(VOCs) removal technology because of its interactional principles of plasma decomposition and catalytic oxidation.However,the problem of harmful by-products is still in trouble.A series of rare earth doped RE-NiO_(x)(RE=Ce,Y,La) composite oxides were synthesized by metal organic frameworks(MOFs)-derived method for coupled plasma oxidation of benzene and by-product ozone removal.Compared with plasma alone,the 1%La-NiO_(x)catalyst shows the best enhancement of 50% for benzene conversion with complete removal of a maximum of 800 ppm ozone.The energy consumption for 90% benzene removal efficiency(η90%) is also reduced from 3600 to 1200 J/L.Characterization re sults of RE-NiO_(x) catalysts indicate that the doping of La causes interaction and synergistic effect between La and Ni,and the surface oxygen and lattice oxygen with defects play crucial roles in benzene oxidation and ozone decomposition,respectively.In addition,the decomposition mechanism of benzene and ozone under plasma is proposed.Plasma is responsible for the indiscriminate bond breaking in benzene and oxygen to form a variety of organic intermediates and ozone,while the La-NiO_(x) catalyst selectively oxidizes the intermediates to CO_(x)/H2O and decomposes the ozone into oxygen.展开更多
Fe-BEA catalysts are active for the NH3-SCR of NO. For industrial application, a binder should be added to the Fe-BEA catalysts to make them tightly adhere to the monoliths. The addition of alumina and zirconia as bin...Fe-BEA catalysts are active for the NH3-SCR of NO. For industrial application, a binder should be added to the Fe-BEA catalysts to make them tightly adhere to the monoliths. The addition of alumina and zirconia as binders to the Fe-BEA led to a different effect on NO conversion. The catalytic activity of the mixed samples was evaluated by the temperature programmed procedure in a flow-reactor sys!em, and themechaism was. analyzedvia SEM, BET, andXPS. Itwas found that larger ironparticles were tbrmed by the migration orparent tron pamcles in the Fe-BEA catalyst with alumina. This led to the increase of Fe3＋ magnitude and iron cluster, enhancing the abilities of NO oxidation and storage. Accordingly, the SCR activity increased slightly in low temperature but decreased sharply in high temperature. For the Fe-BEA with zirconia sample, NO oxidation and storage abilities decreased due to the less iron clusters. The increase of Fe ＋ magnitude resulted in higher catalytic oxidation ability, which gave rise to little change in the SCR activity compared with the Fe-BEA.展开更多
The performance of organic solar cells(OSCs)is mainly related to the bulk heterojunction(BHJ)microstructure of specific active layer systems,which is often in a metastable state.A promising strategy to address the abo...The performance of organic solar cells(OSCs)is mainly related to the bulk heterojunction(BHJ)microstructure of specific active layer systems,which is often in a metastable state.A promising strategy to address the abovementioned shortcomings of BHJs is to develop single-component active layer materials.Owing to the single-component small molecule materials with defined chemical structures generally exhibit poor absorption spectra,herein we first introduced narrow bandgap Y-series acceptors into the molecular skeleton of single-component materials,and designed two molecular dyads,SM-Et-1Y and SM-Et-2Y.The optical bandgaps(E_g~(opt)s)of the two dyads are 1.364 and 1.361 eV,respectively,which are much smaller than those of previously reported single-component molecules.Consequently,the SM-Et-2Y-based single-component OSCs(SCOSCs)showed a power conversion efficiency(PCE)of 5.07%,superior to SM-Et-1Y(2.53%),which is one of the highest PCEs reported for SCOSCs to date.Moreover,both SM-Et-1Y-and SM-Et-2Y-based devices exhibited excellent photo-stability,retaining over 90%of their initial performance after 250 h of continuous illumination.Our results provide a deeper understanding of the molecular backbone and a guiding principle for the rational design or selection of non-fullerene single-component materials with suitable donor/acceptor ratios.展开更多
Objective:To investigate the morphological and ultrastructural alterations in placentas from pregnancies with gestational diabetes mellitus(GDM)–induced macrosomia,term nondiabetic macrosomia,and normal pregnancies.M...Objective:To investigate the morphological and ultrastructural alterations in placentas from pregnancies with gestational diabetes mellitus(GDM)–induced macrosomia,term nondiabetic macrosomia,and normal pregnancies.Methods:Sixty full-term placentaswere collected,and clinical data alongwith informed consent were obtained from pregnant womenwho underwent regular visit checks and delivered their newborns in Northwest Women’s and Children’s Hospital between May and December 2022.Placentas were divided into three equal groups:normal pregnancy(control group),nondiabetic macrosomia group,and macrosomia complicated with GDM(diabetic macrosomia)group.Gross morphological data of placentas were recorded,and placental samples were processed for examination of ultrastructural and stereological changes using transmission electron microscopy.Analysis of variance and chi-squared test were used to examine the differences among the three groups for continuous and categorical variables,respectively.Results:The baseline characteristics of mothers and neonates did not differ across the three groups,except for a significantly higher birth weight in the diabetic macrosomia group(4172.00±151.20 g vs.3192.00±328.70 g,P<0.001)and nondiabetic macrosomia group(4138.00±115.20 g vs.3192.00±328.70 g,P<0.001)comparedwith control group.Examination of the placentas revealed that placental weight was also highest in the diabeticmacrosomia group comparedwith control group(810.00±15.81 g vs.490.00±51.48 g,P<0.001)and nondiabetic macrosomia group(810.00±15.81 g vs.684.00±62.69 g,P<0.001),but the ratio of neonatal birth weight to placental weight(BW/PW)was significantly lower in the diabetic macrosomia group compared with that in the control group(5.15±0.19 vs.6.54±0.63,P<0.001)and nondiabetic macrosomia group(5.15±0.19 vs.6.09±0.52,P<0.001)group.In contrast,the BW/PW ratio in nondiabetic macrosomia did not differ significantly from that in the control group.Distinct ultrastructural changes in terminal villi and stereological alterations in microvilli were observed in the diabetic macrosomia group,including changes in the appearance of cytoplasmic organelles and the fetal capillary endothelium and thickness of the vasculo-syncytial membrane and basal membrane.Conclusion:Significant ultrastructural and stereological alterations were discovered in the placentas from pregnant women with macrosomia induced by GDM.These alterationsmay be the response of the placenta to the hyperglycemia condition encountered during pregnancies complicated with GDM.展开更多
The transmission of pathogenic airborne microorganisms significantly impacts public health and societal functioning.Ensuring healthy indoor air quality in public spaces is critical.Among various air purification techn...The transmission of pathogenic airborne microorganisms significantly impacts public health and societal functioning.Ensuring healthy indoor air quality in public spaces is critical.Among various air purification technologies,electrostatic precipitation and atmospheric pressure nonthermal plasma are notable for their broad-spectrum effectiveness,high efficiency,cost-effectiveness,and safety.This review investigates the primary mechanisms by which these electrostatic methods collect and disinfect pathogenic aerosols.It also delves into recent advancements in enhancing their physical and chemical mechanisms for improve efficiency.Simultaneously,a thorough summary of mathematical models related to the migration and deactivation of pathogenic aerosols in electrostatic purifiers is provided.It will help us to understand the behavior of aerosols in purification systems.Additionally,the review discusses the current research on creating a comprehensive health protection system and addresses the challenges of balancing byproduct control with efficiency.The aim is to establish a foundation for future research and development in electrostatic aerosol purification and develop integrated air purification technologies that are both efficient and safe.展开更多
基金supported by the National Key Research and Development Program of China(2023YFB3208102,2021YFB3200304)the National Natural Science Foundation of China(52073031)+2 种基金Beijing Nova Program(Z211100002121148)Fundamental Research Funds for the Central Universities(E0EG6801X2)the‘Hundred Talents Program’of the Chinese Academy of Sciences.
文摘The use of water resources for energy generation has become increasingly prevalent,encompassing the conversion of kinetic energy from streams,tides,and waves into renewable electrical power.Water energy sources offer numerous benefits,including widespread availability,stability,and the absence of carbon dioxide and other greenhouse gas emissions,making them a clean and environmentally friendly form of energy.In this work,we develop a droplet-based liquid-solid triboelectric nanogenerator(LS-TENG)using sophisticatedly designed inflatable columnar structures with inner and outer dual-electrodes.This device can be utilized to harvest both the internal droplet-rolling mechanical energy and the external droplet-falling mechanical energy,capable of being assembled into various structures for versatile applications.The design incorporates a combined structure of both internal and external TENG to optimize output performance via multiple energy harvesting strategies.The internal structure features a dual-electrode columnar-shaped LS-TENG,designed to harvest fluid kinetic energy from water droplets.By leveraging the back-and-forth motion of a small amount of water within the air column,mechanical energy can be readily collected,achieving a maximum mass power density of 9.02 W·Kg^(−1)and an energy conversion efficiency of 10.358%.The external component is a droplet-based LS-TENG,which utilizes a double-layer capacitor switch effect elucidated with an equivalent circuit model.Remarkably,without the need for pre-charging,a single droplet can generate over 140 V of high voltage,achieving a maximum power density of 7.35 W·m^(−2)and an energy conversion efficiency of 22.058%.The combined LS-TENG with a sophisticated inflatable columnar structure can simultaneously collect multiple types of energy with high efficacy,exhibiting great significance in potential applications such as TENG aeration rollers,inflatable lifejacket,wind energy harvesting,TENG tents,and green houses.
基金financially supported by the National Key Re-search and Development Plan (No. 2017YFC0211804)。
文摘Various manganese oxides(MnOx) prepared via citric acid solution combustion synthesis were applied for catalytic oxidation of benzene. The results showed the ratios of citric acid/manganese nitrate in synthesizing process positively affected the physicochemical properties of MnOx, e.g., BET(Brunauer-Emmett-Teller) surface area, porous structure, reducibility and so on, which were in close relationship with their catalytic performance. Of all the catalysts, the sample prepared at a citric acid/manganese nitrate ratio of 2:1(C2M1) displayed the best catalytic activity with T(90)(the temperature when 90% of benzene was catalytically oxidized) of 212 ℃. Further investigation showed that C2M1 was Mn2O3 with abundant nano-pores, the largest surface area and the proper ratio of surface Mn^4+/Mn^3+, resulting in preferable low-temperature reducibility and abundant surface active adsorbed oxygen species. The analysis results of the in-situ Fourier transform infrared spectroscopy(in-situ FTIR) revealed that the benzene was successively oxidized to phenolate, o-benzoquinone, small molecules(such as maleates, acetates, and vinyl), and finally transformed to CO2 and H2O.
基金supported by the National Natural Science Foundation of China (No. 20807027)the National High-Tech Research and Development Program (863) of China (No. 2010AA064907)
文摘Pt supported on mesoporous silica SBA-15 was investigated as a catalyst for low temperature selective catalytic reduction（SCR） of NO by C 3 H 6 in the presence of excess oxygen.The prepared catalysts were characterized by means of XRD,BET surface area,TEM,NO-TPD,NO/C 3 H 6-TPO,NH 3-TPD,XPS and 27 Al MAS NMR.The effects of Pt loading amount,O 2 /C 3 H 6 concentration,and incorporation of Al into SBA-15 have been studied.It was found that the removal efficiency increased significantly after Pt loading,but an optimal loading amount was observed.In particular,under an atmosphere of 150 ppm NO,150 ppm C 3 H 6,and 18 vol.% O 2,0.5% Pt/SBA-15 showed remarkably high catalytic performance giving 80.1% NOx reduction and 87.04% C 3 H 6 conversion simultaneously at 140°C.The enhanced SCR activity of Pt/SBA-15 is associated with its outstanding oxidation activities of NO to NO 2 and C 3 H 6 to CO 2 in low temperature range.The research results also suggested that higher concentration of O 2 and higher concentration of C 3 H 6 favored NO removal.The incorporation of Al into SBA-15 improved catalytic performance,which could be ascribed to the enhancement of catalyst surface acidity caused by tetrahedrally coordinated AlO 4.Moreover,the catalysts could be easily reused and possessed good stability.
基金supported by the National Natural Science Foundation of China(No.20807027)the Special Foundation of Nanometer Technology from Shanghai Municipal Science and Technology Commission of China(No.0752 nm005)
文摘A 0.5 wt.%Pt/TiO_(2)catalyst was prepared and used for the low-temperature selective catalytic reduction(SCR)of NO with C3H6 in the presence of excess oxygen.The effects of Pt loading and 02 concentration on Pt/TiO_(2)catalytic performance for low-temperature SCR were investigated.It was found that optimal Pt loading was 0.5 wt.%and excess 02 favored low-temperature SCR of NOx.The mechanism of low-temperature SCR of NO with C3H6 was investigated with respect to the behavior of adsorbed species over Pt/TiO_(2)at 150~C using in situ DRIFTS.The results indicated that surface nitrosyl species(Pt~+-NO and Ti3+-NO)and pt2+-CO are main reaction intermediates during the interactions of NO,C3H6 and 02.A simplified NO decomposition mechanism for the low-temperature SCR of NO with C3H6 was proposed.
基金supported by the National Basic Research Program of China(973 Program)(No.2007CB613305)the National High Technology Research and Development Program of China(863 Program)(No.2007AA061405)the Special Foundation of Nanometer Technology(No.0752nm005)from Shanghai Municipal Science and Technology Commission(STCSM)of China
文摘TiO2-WO3 hybrid photocatalysts were prepared using wet-chemical technique,and their energy storage performance was characterized by electrochemical galvanostatic method.TiO2 powder was coupled with WO3 powder,which was used as electron pool and the reductive energy could be stored in.As a result,the prepared TiO2-WO3 had good energy storage ability while pure TiO2 showed no capacity and pure WO3 showed quite low performance.The energy storage ability was affected by the crystal structure of WO3 and calcination temperature.The photocatalyst had better capacity when WO3 had low degree of crystallinity,since its loose structure made it easier for electrons and cations to pass through.The photocatalytic energy storage performance was also affected by the molar ratio of TiO2 to WO3.Energy storage capacity was significantly dependent on the composition,reaching the maximum value at TiO2/WO31:1(mol/mol).
基金supported by the National Natural Science Foundation of China (Nos.52200130 and 22176123)Postdoctoral Science Foundation of China (No.2022M722082)the National Key Research&Development Plan (No.2017YFC0211804)。
文摘Inhalable particle is a harmful air pollutant that causes a significant threat to people's health and ecological environments,which should be removed to purify air,but there exists limited removal efficiency due to particle re-entrainment.Here,Operando observation system based on microscopic visualization method is developed to make in situ test of particle migration,deposition and re-entrainment characteristics on a lab-on-a-chip to achieve the investigation in micro-level scale.The deposition evolution of charged particles is recorded in electric field region intuitively,which confirms the fracture of particle chain occurs during the growth process of deposited particles.It captures the instantaneous process that a larger particle with micron size due to the coagulation of submicron particles fractures from main body of the particle chain for the first time.The analysis of migration behavior of a single submicron particle near electrode surface demonstrates the direct influence of drag force on the fracture of particle chain.This work is the first-time visualization of dynamic process and mechanism elucidation of particle re-entrainment at the micron level,and the findings will provide the theory support for the particle re-entrainment mechanism and bring inspires of enhancing capture efficiency of inhalable particle.
文摘Novel CdS and Bi2S3 hollow nanospheres were prepared by simple “one-pot” biomolecule-assisted hydrothermal method using glutathione (GSH) as sulfur source and structure-directing reagents. The single-phase CdS and Bi2S3 photocatalysts were capable of evolving H2 from aqueous solutions containing a sacrificial electron donor, under visible light irradiation (λ ≥ 420 nm) with Pt co-catalyst. A possible formation mechanism of complexation, S-C bond rupture, and spherical aggregate followed isotropic Ostwal ripening or anisotropic Ostwal ripening was proposed in this study.
基金Project supported by the National Natural Science Foundation of China(22176123,U1832155)the National Key Research&Development Plan(2017YFC0211804).
文摘Plasma-coupled catalysis is a promising volatile organic co mpounds(VOCs) removal technology because of its interactional principles of plasma decomposition and catalytic oxidation.However,the problem of harmful by-products is still in trouble.A series of rare earth doped RE-NiO_(x)(RE=Ce,Y,La) composite oxides were synthesized by metal organic frameworks(MOFs)-derived method for coupled plasma oxidation of benzene and by-product ozone removal.Compared with plasma alone,the 1%La-NiO_(x)catalyst shows the best enhancement of 50% for benzene conversion with complete removal of a maximum of 800 ppm ozone.The energy consumption for 90% benzene removal efficiency(η90%) is also reduced from 3600 to 1200 J/L.Characterization re sults of RE-NiO_(x) catalysts indicate that the doping of La causes interaction and synergistic effect between La and Ni,and the surface oxygen and lattice oxygen with defects play crucial roles in benzene oxidation and ozone decomposition,respectively.In addition,the decomposition mechanism of benzene and ozone under plasma is proposed.Plasma is responsible for the indiscriminate bond breaking in benzene and oxygen to form a variety of organic intermediates and ozone,while the La-NiO_(x) catalyst selectively oxidizes the intermediates to CO_(x)/H2O and decomposes the ozone into oxygen.
文摘Fe-BEA catalysts are active for the NH3-SCR of NO. For industrial application, a binder should be added to the Fe-BEA catalysts to make them tightly adhere to the monoliths. The addition of alumina and zirconia as binders to the Fe-BEA led to a different effect on NO conversion. The catalytic activity of the mixed samples was evaluated by the temperature programmed procedure in a flow-reactor sys!em, and themechaism was. analyzedvia SEM, BET, andXPS. Itwas found that larger ironparticles were tbrmed by the migration orparent tron pamcles in the Fe-BEA catalyst with alumina. This led to the increase of Fe3＋ magnitude and iron cluster, enhancing the abilities of NO oxidation and storage. Accordingly, the SCR activity increased slightly in low temperature but decreased sharply in high temperature. For the Fe-BEA with zirconia sample, NO oxidation and storage abilities decreased due to the less iron clusters. The increase of Fe ＋ magnitude resulted in higher catalytic oxidation ability, which gave rise to little change in the SCR activity compared with the Fe-BEA.
基金supported by the National Natural Science Foundation of China(52061135206,22279094)the Fundamental Research Funds for the Central Universities。
文摘The performance of organic solar cells(OSCs)is mainly related to the bulk heterojunction(BHJ)microstructure of specific active layer systems,which is often in a metastable state.A promising strategy to address the abovementioned shortcomings of BHJs is to develop single-component active layer materials.Owing to the single-component small molecule materials with defined chemical structures generally exhibit poor absorption spectra,herein we first introduced narrow bandgap Y-series acceptors into the molecular skeleton of single-component materials,and designed two molecular dyads,SM-Et-1Y and SM-Et-2Y.The optical bandgaps(E_g~(opt)s)of the two dyads are 1.364 and 1.361 eV,respectively,which are much smaller than those of previously reported single-component molecules.Consequently,the SM-Et-2Y-based single-component OSCs(SCOSCs)showed a power conversion efficiency(PCE)of 5.07%,superior to SM-Et-1Y(2.53%),which is one of the highest PCEs reported for SCOSCs to date.Moreover,both SM-Et-1Y-and SM-Et-2Y-based devices exhibited excellent photo-stability,retaining over 90%of their initial performance after 250 h of continuous illumination.Our results provide a deeper understanding of the molecular backbone and a guiding principle for the rational design or selection of non-fullerene single-component materials with suitable donor/acceptor ratios.
基金supported by the research grant from the Key Research and Development Program of Shaanxi Province(no.2022SF-125,2021ZDLSF02-14).
文摘Objective:To investigate the morphological and ultrastructural alterations in placentas from pregnancies with gestational diabetes mellitus(GDM)–induced macrosomia,term nondiabetic macrosomia,and normal pregnancies.Methods:Sixty full-term placentaswere collected,and clinical data alongwith informed consent were obtained from pregnant womenwho underwent regular visit checks and delivered their newborns in Northwest Women’s and Children’s Hospital between May and December 2022.Placentas were divided into three equal groups:normal pregnancy(control group),nondiabetic macrosomia group,and macrosomia complicated with GDM(diabetic macrosomia)group.Gross morphological data of placentas were recorded,and placental samples were processed for examination of ultrastructural and stereological changes using transmission electron microscopy.Analysis of variance and chi-squared test were used to examine the differences among the three groups for continuous and categorical variables,respectively.Results:The baseline characteristics of mothers and neonates did not differ across the three groups,except for a significantly higher birth weight in the diabetic macrosomia group(4172.00±151.20 g vs.3192.00±328.70 g,P<0.001)and nondiabetic macrosomia group(4138.00±115.20 g vs.3192.00±328.70 g,P<0.001)comparedwith control group.Examination of the placentas revealed that placental weight was also highest in the diabeticmacrosomia group comparedwith control group(810.00±15.81 g vs.490.00±51.48 g,P<0.001)and nondiabetic macrosomia group(810.00±15.81 g vs.684.00±62.69 g,P<0.001),but the ratio of neonatal birth weight to placental weight(BW/PW)was significantly lower in the diabetic macrosomia group compared with that in the control group(5.15±0.19 vs.6.54±0.63,P<0.001)and nondiabetic macrosomia group(5.15±0.19 vs.6.09±0.52,P<0.001)group.In contrast,the BW/PW ratio in nondiabetic macrosomia did not differ significantly from that in the control group.Distinct ultrastructural changes in terminal villi and stereological alterations in microvilli were observed in the diabetic macrosomia group,including changes in the appearance of cytoplasmic organelles and the fetal capillary endothelium and thickness of the vasculo-syncytial membrane and basal membrane.Conclusion:Significant ultrastructural and stereological alterations were discovered in the placentas from pregnant women with macrosomia induced by GDM.These alterationsmay be the response of the placenta to the hyperglycemia condition encountered during pregnancies complicated with GDM.
基金supported by the National Key Research&Development Plan(2017YFC0211804)the National Natural Science Foundation of China(21577088,22176123).
文摘The transmission of pathogenic airborne microorganisms significantly impacts public health and societal functioning.Ensuring healthy indoor air quality in public spaces is critical.Among various air purification technologies,electrostatic precipitation and atmospheric pressure nonthermal plasma are notable for their broad-spectrum effectiveness,high efficiency,cost-effectiveness,and safety.This review investigates the primary mechanisms by which these electrostatic methods collect and disinfect pathogenic aerosols.It also delves into recent advancements in enhancing their physical and chemical mechanisms for improve efficiency.Simultaneously,a thorough summary of mathematical models related to the migration and deactivation of pathogenic aerosols in electrostatic purifiers is provided.It will help us to understand the behavior of aerosols in purification systems.Additionally,the review discusses the current research on creating a comprehensive health protection system and addresses the challenges of balancing byproduct control with efficiency.The aim is to establish a foundation for future research and development in electrostatic aerosol purification and develop integrated air purification technologies that are both efficient and safe.
