Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ...Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ability of particulate matter allows EPFRs to migrate over long-distance transport,thereby impacting the quality of the local atmospheric environment.Additionally,EPFRs can also adhere to atmospheric particles and interact with typical gaseous pollutants to affect atmospheric chemical reactions.EPFRs can produce some reactive organic species,promoting oxidative stress in the human body,damaging biological macromolecules and ultimately affecting the organism health.EPFRs are considered as a novel type of pollutant that affects human health.Despite their significance,there are few literatures available on the characteristics and fate behaviors of EPFRs up to date.Therefore,supplemental reviews are crucial for providing comprehensive understanding of EPFRs.Materials and methods This review summarizes the characteristics of EPFRs in particulate matter,outlines the generation mechanism and influencing factors of EPFRs,and the impacts of EPFRs on environmental quality and organism health.Results The content of EPFRs in particulate matter ranges from 1017 to 1020 spins∙g−1.Due to the strong mobility of atmospheric particulate matter,the long-term exposure to high levels of EPFRs may aggravate the impact of particulate matter on human health.The interaction between EPFRs and typical gaseous pollutants can alter their fate and influence atmospheric chemical reactions.EPFRs are mainly produced by transition metal elements and substituted aromatic hydrocarbons through electron transfer.Additionally,the chemical bond rupture of organic substances through heat treatment or ultraviolet radiation can also produce EPFRs,and heterogeneous reactions are capable producing them as well.The production of EPFRs is not only influenced by transition metal elements and precursors,but also by various environmental factors such as oxygen,temperature,light radiation,and relative humidity.Discussion EPFRs in atmospheric particulates matters are usually rich in fine particulates with obvious seasonal and regional variations.They can easily enter the human respiratory tract and lungs with inhalable particulates,thereby increasing the risk of exposure.Additionally,EPFRs in atmospheric particulates can interact with some typical gaseous pollutants,impacting the life and fate of EPFRs in the atmosphere,and alter atmospheric chemical reactions.Traditionally,EPFRs are generated by transition metal elements and substituted aromatic hydrocarbons undergoing electron transfer in the post-flame and cool-zone regions of combustion systems and other thermal processes to remove HCl,H_(2)O or CO groups,ultimately produce semiquinones,phenoxyls,and cyclopentadienyls.Recent studies have indicated that EPFRs can also be generated under the conditions of without transition metal elemental.Organics can also produce EPFRs through chemical bond rupture during heat treatment or light radiation conditions,as well as through some heterogeneous reactions and photochemical secondary generation of EPFRs.The presence or absence of oxygen has different effects on the type and yield of EPFRs.The concentration,type,and crystal type of transition metal elements will affect the type,content,and atmospheric lifetime of EPFRs.It is generally believed that the impact of transition metal element types on EPFRs is related to the oxidation-reduction potential.The combustion temperature or heat treatment process significantly affects the type and amount of EPFRs.Factors such as precursor loading content,pH conditions,light radiation and relative humidity also influence the generation of EPFRs.EPFRs can interact with pollutants in the environment during their migration and transformation process in environmental medium.This process accelerates the degradation of pollutants and plays a crucial role in the migration and transformation of organic pollutants in environmental media.The reaction process of EPFRs may lead to the production of reactive oxygen species(ROS)such as∙OH,which can induce oxidative stress,inflammation and immune response to biological lung cells and tissues,leading to chronic respiratory and cardiopulmonary dysfunction,cardiovascular damage and neurotoxic effects,ultimately impacting the health of organisms.Conclusions The interaction mechanism between EPFRs in particulate matter and gaseous pollutants remains unclear.Furthermore,research on the generation mechanism of EPFRs without the participation of transition metals is not comprehensive,and the detection of EPFRs is limited to simple qualitative categories and lack accurate qualitative analysis.Recommendations and perspectives Further research should be conducted on the generation mechanism,measurement techniques,migration pathways,and transformation process of EPFRs.It is also important to explore the interaction between EPFRs in atmospheric particulate matter and typical gaseous pollutants.展开更多
The microwave induced argon plasma was applied to the preparation of NaOH-activated carbon from sugar cane bagasse. The distinguished feature of the heating technique with this cold plasma is the short operation time....The microwave induced argon plasma was applied to the preparation of NaOH-activated carbon from sugar cane bagasse. The distinguished feature of the heating technique with this cold plasma is the short operation time. The carbonization and the activation process were finalized in one step within 3 min. The prepared activated carbon with NaOH ratio 3 to bagasse characterized using N2 adsorption of type IV (IUPAC classification) to give specific surface area of 1980 m2/g and mesopore volume of 0.73 ml/g. It also showed a higher specific capacitance of 201 F/g in 1 M H2SO4 solution (with standard three electrodes) than the corresponding one by the conventional heating, previously reported. The other features were the absence of oxygen groups and the presence of carbon centered stable radicals, detected by ESR spectra, on the surface.展开更多
Nitrogen is widely used to prevent the spontaneous combustion of coal in underground coal mines. A spontaneous combustion-prone coal seam was studied to investigate the restraining effect of nitrogen on coal oxidation...Nitrogen is widely used to prevent the spontaneous combustion of coal in underground coal mines. A spontaneous combustion-prone coal seam was studied to investigate the restraining effect of nitrogen on coal oxidation in different oxidation stages, based on non-isothermal thermogravimetry-differential scanning calorimetry(TG-DSC) and electron paramagnetic resonance(EPR) experiments. We found that the key feature temperatures grow steadily with increasing nitrogen in the oxidation environment,resulting in longer oxidation stages. The most significant finding is that there is a stagnation of the inhibitory effect of nitrogen on coal oxidation in the range of 85.0–95.0% nitrogen in the slow and the rapid oxidation stages, owing to the competitive adsorption of coal by nitrogen and oxygen. However, the restraining effect cannot be reflected by the kinetic parameters of the coal before it reaches the thermal decomposition and combustion stage. Nitrogen can also affect free radical types and free radical concentrations during coal oxidation: the higher the concentration of nitrogen in the oxidation environment, the greater the number of free radical types and the lower the free radical concentration. This experimental study improves the understanding of the restraining effect of nitrogen on coal oxidation in different oxidation stages and provides an important reference for coal fire prevention in spontaneous combustionprone coal seams.展开更多
In order to discuss the role and influence of water during the generation of natural gas,the participation mechanism of water during the evolution of organic matter and its influences were summarized.In addition,we ca...In order to discuss the role and influence of water during the generation of natural gas,the participation mechanism of water during the evolution of organic matter and its influences were summarized.In addition,we carried out an anhydrous cracking experiment of oil extracted from the Feixianguan Formation source rock in a closed system,which led to the establishment of the kinetic models for describing carbon and hydrogen isotopic fractionation during gas generation from organic matter.The models were calibrated and then applied to the northeastern Sichuan Basin.By combining a series of gas generation experiments from octadecane pyrolysis without water or with distilled water in varying mass proportions,several results were proved:(1) the hydrogen isotopic composition of natural gas becomes lighter with the participation of formation water;(2) we can quantitatively study the hydrogen isotopic fractionation with the kinetic model for describing carbon isotopic fractionation; (3) more abundant and reliable geological information can be obtained through the combined application of carbon and hydrogen isotopic indices.展开更多
Objective:To evaluate the photoprotective,antioxidant,antiglycation,and antiacne activities of crude extract(CESs)and triterpene saponin fraction(TSSs)of Sapindus saponaria.Methods:HPLC-MS purification was performed o...Objective:To evaluate the photoprotective,antioxidant,antiglycation,and antiacne activities of crude extract(CESs)and triterpene saponin fraction(TSSs)of Sapindus saponaria.Methods:HPLC-MS purification was performed on a Symmetry TM C18 column.The saponins were identified by a UV detector.Antioxidant activity was evaluated by DPPH and O_(2)^(−)radicals scavenging,and FRAP and TBARS assays.Glycation activity was assessed by relative electrophoretic mobility and inhibition of advanced glycation end products(AGEs)formation.Additionally,antiacne activity was determined by inhibition of Cutibacterium acnes,and photoprotective effect was evaluated by Mansur’s method.Results:Most of the triterpene saponins detected in the fraction by HPLC-MS analysis were hederagenin as the aglycon.CESs and TSSs presented varying antioxidant activity in DPPH(CESs:75.69%and TSSs:83.65%),FRAP(CESs:425.39μM TE/g DW and TSSs:649.36μM TE/g DW),TBARS(CESs:42.96%and TSSs:52.16%)and O_(2)^(−)radicals scavenging(CESs:61.33%and TSSs:86.69%)tests.CESs and TSSs also exhibited antiglycation activity comparable to bovine serum albumin treated with aminoguanidine.In addition,CESs and TSSs showed inhibition of AGE formation(34.48%and 61.85%,respectively).Antiacne activity against Cutibacterium acnes was observed with a minimum inhibitory concentration equal to minimum bactericidal concentration(CESs:36.11µg/mL and TSSs:18.34µg/mL).In photoprotective assays,CESs and TSSs showed maximum absorbance of 1.42 to 0.20 and 2.80 to 1.30,respectively,in the wavelength range of 260 to 400 nm.Furthermore,CESs and TSSs showed sun protection factors of 8.89 and 14.89,respectively.Conclusions:Sapindus saponaria fruit extracts show strong antioxidant potential and antiglycation activity against bovine serum albumin glycation and AGE formation.Besides,they presented antibacterial activity against Cutibacterium acnes and photoprotective effect against UV-A and UV-B.展开更多
Calcium sulfoaluminate,3CaO·3Al2O3·CaSO4,has been widely recognized in the realms of high-temperature combustion and cement chemistry.However,the lack of relevant thermodynamic data limits the progress of it...Calcium sulfoaluminate,3CaO·3Al2O3·CaSO4,has been widely recognized in the realms of high-temperature combustion and cement chemistry.However,the lack of relevant thermodynamic data limits the progress of its research and development.Through comparative calculations using several different approaches,we obtain the thermochemical properties of 3CaO·3Al2O3·CaSO4 in this work,such as its standard formation enthalpy,Gibbs free en- ergy of formation,entropy,and molar heat capacity.With these fundamental data,thermodynamic calculations become possible for reactions involving this mineral.It is found that some reactions proposed in literature to generate this mineral may not proceed thermodynamically.展开更多
The nano powders of LaCrO3 were prepared by a sol-gel route. The heat capacity of LaCrO3 nano powders from 350 to 550 K was measured by DSC method and expressed as： Cpa2CrO3） （±0.112） = 166.844 - 8.500 ×...The nano powders of LaCrO3 were prepared by a sol-gel route. The heat capacity of LaCrO3 nano powders from 350 to 550 K was measured by DSC method and expressed as： Cpa2CrO3） （±0.112） = 166.844 - 8.500 ×10^-3T- 1.022×10^6T^-2 （J/（mol.K）） （350-550 K）. An EMF measurement assembly was developed with CaF2 as an electrolyte for the galvanic cell. From measured EMF data of the reversible cell, （-） PL La2O3, LaF3, O2 （1 atm）lCaF2O2（1 atm）, LaF3, LaCrO3, Cr2O3, Pt（＋）, and the relevant value of Gibbs free energy, the Gibbs free energy of formation of LaCrO3 was calculated from 700 to 885 K： △G ФaLaCrO3 = -1555.364 ＋ 0.354T （kJ/mol） （700-885 K）. And the Gibbs free energy change of reaction from simple oxides La2O3 and Cr2O3 was calculated to be： AG f Oox（LaCrO3） = -94.758 ＋ 8.530×10^-2T（kJ/mol） （700-885 K）.展开更多
文摘Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ability of particulate matter allows EPFRs to migrate over long-distance transport,thereby impacting the quality of the local atmospheric environment.Additionally,EPFRs can also adhere to atmospheric particles and interact with typical gaseous pollutants to affect atmospheric chemical reactions.EPFRs can produce some reactive organic species,promoting oxidative stress in the human body,damaging biological macromolecules and ultimately affecting the organism health.EPFRs are considered as a novel type of pollutant that affects human health.Despite their significance,there are few literatures available on the characteristics and fate behaviors of EPFRs up to date.Therefore,supplemental reviews are crucial for providing comprehensive understanding of EPFRs.Materials and methods This review summarizes the characteristics of EPFRs in particulate matter,outlines the generation mechanism and influencing factors of EPFRs,and the impacts of EPFRs on environmental quality and organism health.Results The content of EPFRs in particulate matter ranges from 1017 to 1020 spins∙g−1.Due to the strong mobility of atmospheric particulate matter,the long-term exposure to high levels of EPFRs may aggravate the impact of particulate matter on human health.The interaction between EPFRs and typical gaseous pollutants can alter their fate and influence atmospheric chemical reactions.EPFRs are mainly produced by transition metal elements and substituted aromatic hydrocarbons through electron transfer.Additionally,the chemical bond rupture of organic substances through heat treatment or ultraviolet radiation can also produce EPFRs,and heterogeneous reactions are capable producing them as well.The production of EPFRs is not only influenced by transition metal elements and precursors,but also by various environmental factors such as oxygen,temperature,light radiation,and relative humidity.Discussion EPFRs in atmospheric particulates matters are usually rich in fine particulates with obvious seasonal and regional variations.They can easily enter the human respiratory tract and lungs with inhalable particulates,thereby increasing the risk of exposure.Additionally,EPFRs in atmospheric particulates can interact with some typical gaseous pollutants,impacting the life and fate of EPFRs in the atmosphere,and alter atmospheric chemical reactions.Traditionally,EPFRs are generated by transition metal elements and substituted aromatic hydrocarbons undergoing electron transfer in the post-flame and cool-zone regions of combustion systems and other thermal processes to remove HCl,H_(2)O or CO groups,ultimately produce semiquinones,phenoxyls,and cyclopentadienyls.Recent studies have indicated that EPFRs can also be generated under the conditions of without transition metal elemental.Organics can also produce EPFRs through chemical bond rupture during heat treatment or light radiation conditions,as well as through some heterogeneous reactions and photochemical secondary generation of EPFRs.The presence or absence of oxygen has different effects on the type and yield of EPFRs.The concentration,type,and crystal type of transition metal elements will affect the type,content,and atmospheric lifetime of EPFRs.It is generally believed that the impact of transition metal element types on EPFRs is related to the oxidation-reduction potential.The combustion temperature or heat treatment process significantly affects the type and amount of EPFRs.Factors such as precursor loading content,pH conditions,light radiation and relative humidity also influence the generation of EPFRs.EPFRs can interact with pollutants in the environment during their migration and transformation process in environmental medium.This process accelerates the degradation of pollutants and plays a crucial role in the migration and transformation of organic pollutants in environmental media.The reaction process of EPFRs may lead to the production of reactive oxygen species(ROS)such as∙OH,which can induce oxidative stress,inflammation and immune response to biological lung cells and tissues,leading to chronic respiratory and cardiopulmonary dysfunction,cardiovascular damage and neurotoxic effects,ultimately impacting the health of organisms.Conclusions The interaction mechanism between EPFRs in particulate matter and gaseous pollutants remains unclear.Furthermore,research on the generation mechanism of EPFRs without the participation of transition metals is not comprehensive,and the detection of EPFRs is limited to simple qualitative categories and lack accurate qualitative analysis.Recommendations and perspectives Further research should be conducted on the generation mechanism,measurement techniques,migration pathways,and transformation process of EPFRs.It is also important to explore the interaction between EPFRs in atmospheric particulate matter and typical gaseous pollutants.
文摘The microwave induced argon plasma was applied to the preparation of NaOH-activated carbon from sugar cane bagasse. The distinguished feature of the heating technique with this cold plasma is the short operation time. The carbonization and the activation process were finalized in one step within 3 min. The prepared activated carbon with NaOH ratio 3 to bagasse characterized using N2 adsorption of type IV (IUPAC classification) to give specific surface area of 1980 m2/g and mesopore volume of 0.73 ml/g. It also showed a higher specific capacitance of 201 F/g in 1 M H2SO4 solution (with standard three electrodes) than the corresponding one by the conventional heating, previously reported. The other features were the absence of oxygen groups and the presence of carbon centered stable radicals, detected by ESR spectra, on the surface.
基金supported by the National Key R&D Program of China (2018YFC0807900)“Double First Rate” Independent Innovation Project of CUMT (2018ZZCX05)
文摘Nitrogen is widely used to prevent the spontaneous combustion of coal in underground coal mines. A spontaneous combustion-prone coal seam was studied to investigate the restraining effect of nitrogen on coal oxidation in different oxidation stages, based on non-isothermal thermogravimetry-differential scanning calorimetry(TG-DSC) and electron paramagnetic resonance(EPR) experiments. We found that the key feature temperatures grow steadily with increasing nitrogen in the oxidation environment,resulting in longer oxidation stages. The most significant finding is that there is a stagnation of the inhibitory effect of nitrogen on coal oxidation in the range of 85.0–95.0% nitrogen in the slow and the rapid oxidation stages, owing to the competitive adsorption of coal by nitrogen and oxygen. However, the restraining effect cannot be reflected by the kinetic parameters of the coal before it reaches the thermal decomposition and combustion stage. Nitrogen can also affect free radical types and free radical concentrations during coal oxidation: the higher the concentration of nitrogen in the oxidation environment, the greater the number of free radical types and the lower the free radical concentration. This experimental study improves the understanding of the restraining effect of nitrogen on coal oxidation in different oxidation stages and provides an important reference for coal fire prevention in spontaneous combustionprone coal seams.
基金financially aided by the National Natural Science Foundation of China(No.41002044)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20102322120003)the Foundation for University Key Teacher of Heilongjiang Province of China(No.1251G003)
文摘In order to discuss the role and influence of water during the generation of natural gas,the participation mechanism of water during the evolution of organic matter and its influences were summarized.In addition,we carried out an anhydrous cracking experiment of oil extracted from the Feixianguan Formation source rock in a closed system,which led to the establishment of the kinetic models for describing carbon and hydrogen isotopic fractionation during gas generation from organic matter.The models were calibrated and then applied to the northeastern Sichuan Basin.By combining a series of gas generation experiments from octadecane pyrolysis without water or with distilled water in varying mass proportions,several results were proved:(1) the hydrogen isotopic composition of natural gas becomes lighter with the participation of formation water;(2) we can quantitatively study the hydrogen isotopic fractionation with the kinetic model for describing carbon isotopic fractionation; (3) more abundant and reliable geological information can be obtained through the combined application of carbon and hydrogen isotopic indices.
基金supported by the São Paulo Research Foundation Grant-FAPESP No.2013/10039-1.
文摘Objective:To evaluate the photoprotective,antioxidant,antiglycation,and antiacne activities of crude extract(CESs)and triterpene saponin fraction(TSSs)of Sapindus saponaria.Methods:HPLC-MS purification was performed on a Symmetry TM C18 column.The saponins were identified by a UV detector.Antioxidant activity was evaluated by DPPH and O_(2)^(−)radicals scavenging,and FRAP and TBARS assays.Glycation activity was assessed by relative electrophoretic mobility and inhibition of advanced glycation end products(AGEs)formation.Additionally,antiacne activity was determined by inhibition of Cutibacterium acnes,and photoprotective effect was evaluated by Mansur’s method.Results:Most of the triterpene saponins detected in the fraction by HPLC-MS analysis were hederagenin as the aglycon.CESs and TSSs presented varying antioxidant activity in DPPH(CESs:75.69%and TSSs:83.65%),FRAP(CESs:425.39μM TE/g DW and TSSs:649.36μM TE/g DW),TBARS(CESs:42.96%and TSSs:52.16%)and O_(2)^(−)radicals scavenging(CESs:61.33%and TSSs:86.69%)tests.CESs and TSSs also exhibited antiglycation activity comparable to bovine serum albumin treated with aminoguanidine.In addition,CESs and TSSs showed inhibition of AGE formation(34.48%and 61.85%,respectively).Antiacne activity against Cutibacterium acnes was observed with a minimum inhibitory concentration equal to minimum bactericidal concentration(CESs:36.11µg/mL and TSSs:18.34µg/mL).In photoprotective assays,CESs and TSSs showed maximum absorbance of 1.42 to 0.20 and 2.80 to 1.30,respectively,in the wavelength range of 260 to 400 nm.Furthermore,CESs and TSSs showed sun protection factors of 8.89 and 14.89,respectively.Conclusions:Sapindus saponaria fruit extracts show strong antioxidant potential and antiglycation activity against bovine serum albumin glycation and AGE formation.Besides,they presented antibacterial activity against Cutibacterium acnes and photoprotective effect against UV-A and UV-B.
基金Supported by the National Natural Science Foundation of China(50906046)the National High-Tech Research and Development Program of China(2009AA05Z303)the Program for New Century Excellent Talents in University(NCET-10-0529)
文摘Calcium sulfoaluminate,3CaO·3Al2O3·CaSO4,has been widely recognized in the realms of high-temperature combustion and cement chemistry.However,the lack of relevant thermodynamic data limits the progress of its research and development.Through comparative calculations using several different approaches,we obtain the thermochemical properties of 3CaO·3Al2O3·CaSO4 in this work,such as its standard formation enthalpy,Gibbs free en- ergy of formation,entropy,and molar heat capacity.With these fundamental data,thermodynamic calculations become possible for reactions involving this mineral.It is found that some reactions proposed in literature to generate this mineral may not proceed thermodynamically.
基金This project is financially supported by the National Natural Science Foundation of China (Nos. 50374009, 20331030, and 20571009)
文摘The nano powders of LaCrO3 were prepared by a sol-gel route. The heat capacity of LaCrO3 nano powders from 350 to 550 K was measured by DSC method and expressed as： Cpa2CrO3） （±0.112） = 166.844 - 8.500 ×10^-3T- 1.022×10^6T^-2 （J/（mol.K）） （350-550 K）. An EMF measurement assembly was developed with CaF2 as an electrolyte for the galvanic cell. From measured EMF data of the reversible cell, （-） PL La2O3, LaF3, O2 （1 atm）lCaF2O2（1 atm）, LaF3, LaCrO3, Cr2O3, Pt（＋）, and the relevant value of Gibbs free energy, the Gibbs free energy of formation of LaCrO3 was calculated from 700 to 885 K： △G ФaLaCrO3 = -1555.364 ＋ 0.354T （kJ/mol） （700-885 K）. And the Gibbs free energy change of reaction from simple oxides La2O3 and Cr2O3 was calculated to be： AG f Oox（LaCrO3） = -94.758 ＋ 8.530×10^-2T（kJ/mol） （700-885 K）.
