The valorization of nitrous oxide(N_(2)O)as an oxygen atom donor presents an attractive opportunity for green chemistry applications,leveraging both its industrial abundance and thermodynamically favorable oxidation p...The valorization of nitrous oxide(N_(2)O)as an oxygen atom donor presents an attractive opportunity for green chemistry applications,leveraging both its industrial abundance and thermodynamically favorable oxidation potential.However,practical implementation has been constrained by the inherent kinetic inertness and poor coordinating ability of N_(2)O.While prior studies achieved N_(2)O-mediated conversion of aryl halides to phenols,such transformations necessitated stoichiometric chemical reductants and elevated pressure(2 atm),posing challenges in operational safety and process scalability.This study focuses on an electrochemical strategy that enables efficient oxygen atom transfer under ambient pressure through controlled current application.This methodology facilitates the selective transformation of aryl iodides to phenols without external reducing agents,establishing an environmentally benign synthetic pathway.By replacing traditional chemical reductants with electrons as the sole reducing equivalent,our approach addresses critical sustainability challenges in aromatic oxygenation chemistry while maintaining operational simplicity under mild conditions.展开更多
Nitrous oxide(N_(2)O),as an important gas affecting climate warming,is attracting attention from allwalks of life.This reviewaddresses N_(2)O emissions status in the adipic acid industry,a significant industrial green...Nitrous oxide(N_(2)O),as an important gas affecting climate warming,is attracting attention from allwalks of life.This reviewaddresses N_(2)O emissions status in the adipic acid industry,a significant industrial greenhouse gas source.It elucidates the N_(2)O emission mechanism and influencing factors in adipic acid production.It extensively evaluates N_(2)O emission accounting methods,including Intergovernmental Panel on Climate Change(IPCC)Guidelines,World Resources Institute(WRI)Protocol,and others.While the IPCC emission factor method offers simplicity and comparability,it may lack precision for facilities with advanced emission reduction measures.To address this,a combined modeling and monitoring approach is advocated.It scrutinizes modeling methods(statistical techniques,Greenhouse Gas and Air Pollution Interactions and Synergies,and Life-cycle Assessment)and highlights their reliance on specific data and perspectives.It emphasizes the growing importance of on-site monitoring with mid-IR technology.Additionally,it underscores the potential of aircraft-based and satellite remote sensing for comprehensive N_(2)O emissions data.The reviewalso highlights recent advancements in emission mitigation,particularly in adipic acid synthesis techniques,showing substantial potential for N_(2)O reduction.Innovative paradigms and strategies for N_(2)O mitigation in the adipic acid industry are presented,with a focus on achieving nitrogen oxides(NO_(x))-free production.These approaches hold promise for emission reduction,given the high removal efficiency in plant end-of-treatment processes.Various accounting methods,monitoring techniques,and mitigation strategies were integrated and analyzed to provides a comprehensive overview of N_(2)O emissions in the adipic acid industry,with the aim of guiding future research and policy initiatives.展开更多
The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved ...The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved N_(2)O from large regions such as the Southern Ocean.To address this deficit,N_(2)O was measured in the Prydz Bay in February 2015 during the 31st Chinese National Antarctic Research Expedition.N_(2)O concentrations(saturation)in the surface layer were generally low(undersaturation with respect to atmospheric equilibrium)and ranged from 13.3 nmol/L to 16.1 nmol/L(83%–102%)at the time of sampling.A comparison of our observations with archived data revealed that no discernible trend in N_(2)O concentrations in the surface waters of Prydz Bay could be detected for the period between 2006 and 2015.Temperature and salinity changes driven by meltwater input were the predominant controls on N_(2)O concentrations in surface waters.At depth,the distribution of N_(2)O concentrations was dominated by production via nitrification in offshore deep waters and vertical convection in the shelf waters,where concentrations were lower and gradients were less steep.Our results suggest a rather unusual pattern of N_(2)O distribution in the Prydz Bay(low N_(2)O in shelf waters compared with the open ocean),providing important insights into the coastal dynamics of N_(2)O in high-latitude polar regions.展开更多
The objectives of this study which included two experiments were to investigate the effects of dietary inclusion of sorghum grain rich in condensed tannins(CT)(18.9 g kg^(–1)dry matter(DM))on nitrogen(N)metabolism an...The objectives of this study which included two experiments were to investigate the effects of dietary inclusion of sorghum grain rich in condensed tannins(CT)(18.9 g kg^(–1)dry matter(DM))on nitrogen(N)metabolism and urine nitrous oxide(N_(2)O)emissions of beef steers.In experiment 1,six Limousin×Luxi crossbreed steers with an initial liveweight of(245.0±18.7)kg were used as experimental animals.Three levels of sorghum grain,i.e.,0,167 and 338 g kg^(–1)DM were included in diets as experimental treatments.The animals and the treatments were randomly assigned to a replicated 3×3 Latin square design.In experiment 2,static incubation technique was used to determine the N_(2)O emissions of the urine samples collected in experiment 1.The results of experiment 1 showed that dietary inclusion of sorghum grain linearly increased the faecal N excretion(P=0.001),the total N excretion(P=0.010)and the faecal N to N intake ratio(P=0.021),but it did not affect the N retention and the N utilization efficiency(P>0.10).The plasma metabolomic data showed that dietary inclusion of sorghum grain increased the relative concentrations of phenolic acid(N1,N5,N10-tris-trans-p-coumaroylspermine and prenyl cis-caffeate)and carnitine(3-hydroxyisovalerylcarnitine and linoelaidyl carnitine).The results also showed that dietary inclusion of sorghum grain linearly increased the urinary urea excretion(P=0.010)and decreased the urinary excretion of purine derivatives(P=0.041)as well as the estimated rumen microbial N supply(P=0.012)based on urinary purine derivatives.The results of experiment 2 showed that including sorghum grain in the diet linearly increased the average concentrations of NH_(4)^(+)-N(P=0.012),NO_(2)^(–)-N(P=0.009),NO_(3)^(-)-N(P=0.001)and the total inorganic N(P<0.001)in the soil enriched with urine samples.The urine sample N_(2)O-N flux(P=0.001),the estimated steer urine N_(2)O-N flux(P=0.021)and the N_(2)O-N to urinary N ratio(P=0.038)linearly increased with increasing inclusion of sorghum grain in the diet.In conclusion,dietary inclusion of sorghum grain containing high CT at 167 and 338 g kg^(–1)DM did not affect the N utilization efficiency of steers but increased the urine N_(2)O-N emissions by 5.7 and 31.4%,respectively.For reducing the N_(2)O emissions to the environment,high levels of sorghum grain should not be included in the diet of steers.展开更多
Eutrophic shallow lakes are generally considered as a contributor to the emission of nitrous oxide(N_(2)O),while regional and global estimates have remained imprecise.This due to a lack of data and insufficient unders...Eutrophic shallow lakes are generally considered as a contributor to the emission of nitrous oxide(N_(2)O),while regional and global estimates have remained imprecise.This due to a lack of data and insufficient understanding of the multiple contributing factors.This study characterized the spatiotemporal variability in N_(2)O concentrations and N_(2)O diffusive fluxes and the contributing factors in LakeWuliangsuhai,a typical shallow eutrophic and seasonally frozen lake in Inner Mongolia with cold and arid climate.Dissolved N_(2)O concentrations of the lake exhibited a range of 4.5 to 101.2 nmol/L,displaying significant spatiotemporal variations.The lowest and highest concentrations were measured in summer and winter,respectively.The spatial distribution of N_(2)Ofluxwas consistent with that of N_(2)O concentrations.Additionally,the hotspots of N_(2)O emissions were detected within close to the main inflow of lake.The wide spatial and temporal variation in N_(2)O emissions indicate the complexity and its relative importance of factors influencing emissions.N_(2)O emissions in different lake zones and seasons were regulated by diverse factors.Factors influencing the spatial and temporal distribution of N_(2)O concentrations and fluxes were identified as WT,WD,DO,Chl-a,SD and COD.Interestingly,the same factor demonstrated opposing effects on N_(2)O emission in various seasons or zones.This research improves our understanding of N_(2)O emissions in shallow eutrophic lakes in cold and arid areas.展开更多
Iron-containing zeolites play an important role in the selective oxidation of methane to oxygenates by nitrous oxide.A solid-state ion exchange method is adopted to prepare Fe-MOR zeolite catalysts with different amou...Iron-containing zeolites play an important role in the selective oxidation of methane to oxygenates by nitrous oxide.A solid-state ion exchange method is adopted to prepare Fe-MOR zeolite catalysts with different amounts of extra-framework Al.EPR spectra and UV-vis spectra show that the percentage of iron ions in tetrahedral or octahedral coordination increases while those of clustered Fe species decrease by the addition of extra-framework Al species.Nitrous oxide titration reveals that more active Fe centers are formed,which promote the nitrous oxide consumption.The number of active centers in the catalyst with the introduction of extra-framework Al is about four times that of the catalyst without the addition of extra-framework Al.Due to this,there is an increase in the methane conversion,total selectivity and yield of oxygenates.展开更多
This paper monitors the differences of early rice yield and the emissions of methane and nitrous oxide in the paddy field, based on the different cultivation technologies（high-yield scattered-planting mode, transplan...This paper monitors the differences of early rice yield and the emissions of methane and nitrous oxide in the paddy field, based on the different cultivation technologies（high-yield scattered-planting mode, transplanting mode, farmer-planting mode）. Results suggested that the rice yield by high-yield scattered-planting mode and transplanting mode was significantly higher than farmer-planting mode, and the increase reached 16.4% and 17.7%. The difference of high-yield scattered-planting mode and transplanting mode was insignificant. The potential contributions of the methane amount by these three patterns to the global contribution were all above90%. The emission of methane during the growth period by the high-yield scatteredplanting mode was dramatically lower than that by transplanting mode and farmerplanting mode, while the differences between the high-yield transplanting mode and the farmer mode were insignificant. The changes of global temperature increase and the emission of methane were the same. The greenhouse gas intensity of high-yield scattered-planting mode was the lowest, and the farmer-planting mode was the highest. Therefore, the scattered-planting with reasonable fertilizing method is the most essential way to realize high yield of rice and the reducing the greenhouse gas emission as well.展开更多
This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0...This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.展开更多
Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structur...Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.展开更多
Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capac...Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capacity fading.Herein,the dual-strategy of Cr,B complex coating and local gradient doping is simultaneously achieved on LLO surface by a one-step wet chemical reaction at room temperature.Density functional theory(DFT)calculations prove that stable B-O and Cr-O bonds through the local gradient doping can significantly reduce the high-energy O 2p states of interfacial lattice O,which is also effective for the near-surface lattice O,thus greatly stabilizing the LLO surface,Besides,differential electrochemical mass spectrometry(DEMS)indicates that the Cr_(x)B complex coating can adequately inhibit oxygen release and prevents the migration or dissolution of transition metal ions,including allowing speedy Li^(+)migration,The voltage and capacity fading of the modified cathode(LLO-C_(r)B)are adequately suppressed,which are benefited from the uniformly dense cathode electrolyte interface(CEI)composed of balanced organic/inorganic composition.Therefore,the specific capacity of LLO-CrB after 200 cycles at 1C is 209.3 mA h g^(-1)(with a retention rate of 95.1%).This dual-strategy through a one-step wet chemical reaction is expected to be applied in the design and development of other anionic redox cathode materials.展开更多
Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemist...Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemistry of O3-type layered oxide cathode materials.This work systematically investigates the effect of Fe doping on the anionic oxygen redox chemistry and electrochemical reactions in O3-NaNi_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1)O_(2).The results of the density functional theory(DFT)calculations indicate that the electrons of the O 2p occupy a higher energy level.In the ex-situ X-ray photoelectron spectrometer(XPS)of O 1s,the addition of Fe facilitates the lattice oxygen(O^(n-))to exhibit enhanced activity at 4.45 V.The in-situ X-ray diffraction(XRD)demonstrates that the doping of Fe effectively suppresses the Y phase transition at high voltages.Furthermore,the Galvanostatic Intermittent Titration Technique(GITT)data indicate that Fe doping significantly increases the Na~+migration rate at high voltages.Consequently,the substitution of Fe can elevate the cut-off voltage to 4.45 V,thereby facilitating electron migration from O^(2-).The redox of O^(2-)/O^(n-)(n<2)contributes to the overall capacity.O3-Na(Ni_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1))_(0.92)Fe_(0.08)O_(2)provides an initial discharge specific capacity of 180.55 mA h g^(-1)and71.6%capacity retention at 0.5 C(1 C=240 mA g^(-1)).This work not only demonstrates the beneficial impact of Fe substitution for promoting the redox activity and reversibility of O^(2-)in 03-type layered oxides,but also guarantees the structural integrity of the cathode materials at high voltages(>4.2 V).It offers a novel avenue for investigating the anionic redox reaction in O3-type layered oxides to design advanced cathode materials.展开更多
On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil ...On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil particles.However,soil particles on the Earth with the similar composition lack such structures and properties.This discrepancy raises a key question whether there is a direct relationship between solar wind irradiation and the alterations in the structure and chemical performance of extraterrestrial materials.To address this question,this work investigates the effects of proton irradiation,simulating solar wind radiation,on the structure and photothermal catalytic properties of the classic catalyst In_(2)O_(3).It reveals that proton irradiation induces structural features in In_(2)O_(3) analogous to those characteristics of solar wind weathering observed in extraterrestrial materials.Furthermore,after proton beam irradiation with an energy of 30 keV and a dose of 3×10^(17) protons·cm^(-2),the methanol production yield of the In_(2)O_(3) catalyst increased to 2.6 times of its preirradiation level,and the methanol selectivity improved to 2.1 times of the original value.This work provides both theoretical and experimental support for the development of high-efficiency,radiation-resistant photothermal catalysts.展开更多
Many studies have focused on various agricultural management measures to reduce agricultural nitrous oxide （N2O） emission. However, few studies have investigated soil N2O emissions in intercropping systems in the No...Many studies have focused on various agricultural management measures to reduce agricultural nitrous oxide （N2O） emission. However, few studies have investigated soil N2O emissions in intercropping systems in the North China Plain. Thus, we conducted a ifeld experiment to compare N2O emissions under monoculture and maize-legume intercropping systems. In 2010, ifve treatments, including monocultured maize （M）, maize-peanut （MP）, maize-alfalfa （MA）, maize-soybean （MS）, and maize-sweet clover （MSC） intercropping were designed to investigate this issue using the static chamber technique. In 2011, M, MP, and MS remained, and monocultured peanuts （P） and soybean （S） were added to the trial. The results showed that total production of N2O from different treatments ranged from （0.87＆#177;0.12） to （1.17＆#177;0.11） kg ha-1 in 2010, while those ranged from （3.35＆#177;0.30） to （9.10＆#177;2.09） kg ha-1 in 2011. MA and MSC had no signiifcant effect on soil N2O production compared to that of M （P＆lt;0.05）. Cumulative N2O emissions from MP in 2010 were signiifcantly lower than those from M, but the result was the opposite in 2011 （P＆lt;0.05）. MS signiifcantly reduced soil N2O emissions by 25.55 and 48.84%in 2010 and 2011, respectively （P＆lt;0.05）. Soil N2O emissions were signiifcantly correlated with soil water content, soil temperature, nitriifcation potential, soil NH4＋, and soil NO3-content （R2=0.160-0.764, P＆lt;0.01）. A stepwise linear regression analysis indicated that soil N2O release was mainly controlled by the interaction between soil moisture and soil NO3-content （R2=0.828, P＆lt;0.001）. These results indicate that MS had a coincident effect on soil N2O lfux and signiifcantly reduced soil N2O production compared to that of M over two growing seasons.展开更多
Nitrous oxide （N2O） emission during denitrification is receiving intensive attention due to its high potential to cause greenhouse effects. In this study, denitrifiers were acclimated in sequencing batch reactors wi...Nitrous oxide （N2O） emission during denitrification is receiving intensive attention due to its high potential to cause greenhouse effects. In this study, denitrifiers were acclimated in sequencing batch reactors with methanol or acetate as the electron donor and nitrate as the electron acceptor. The effects of ammonium on NzO emission were examined in batch experiments with various electron donors. With the addition of ammonium, N2O emission increased under all the examined conditions compared to experiments without ammonium addition. With different electron donors, the highest ratio of N2O emission to the removed oxidized nitrogen was 0.70% for methanol, 5.34% for acetate, and 34.79% for polyhydroxybutyrate.展开更多
A laboratory incubation experiment was conducted to investigate nitrous oxide(N 2O) emission and reduction in a paddy soil(Stagnic Anthrosol) response to the pretreatment of water regime. The paddy soil was maintaine...A laboratory incubation experiment was conducted to investigate nitrous oxide(N 2O) emission and reduction in a paddy soil(Stagnic Anthrosol) response to the pretreatment of water regime. The paddy soil was maintained under either air dried(sample D) or submerged(sample F) conditions for 110 d before the soil was adjusted into soil moisture of 20%, 40%, 60%, 80% and 100% water holding capacity(WHC) respectively, and then incubated with or without 10%(v/v) acetylene for 138 h at 25℃. At lower soil water content (≤60% WHC), N 2O emission from the sample F was 2 29 times higher than that from the sample D( P <0 01). While, N 2O emission from the sample F was only 29 and 14 percent of that from the sample D at the soil moisture of 80% and 100% WHC, respectively( P <0 01). The maximal N 2O emissions observed at soil moisture of 80% WHC were about 24 and 186 times higher than the minima obtained at the soil moisture of 20% WHC for the sample F and D, respectively. But at the soil moisture of 80% and 100% WHC, N 2O emission from the sample F with acetylene(F+ACE) was comparable to that of the sample D with acetylene (D+ACE). The results showed that the F sample produced N 2O ability in denitrification was similar to the sample D, however, the sample F was in the better reduction of N 2O to N 2 than the sample D even after the soil moisture was adjusted into the same level of 80% or 100% WHC. Therefore, the pretreatment of water regime influenced the strength and product composition of denitrification and N 2O emission from the paddy soil.展开更多
Nitrous oxide （N 2 O） emissions from a maize field in the North China Plain （Wangdu County,Hebei Province,China） were investigated using static chambers during two consecutive maize growing seasons in the 2008 and...Nitrous oxide （N 2 O） emissions from a maize field in the North China Plain （Wangdu County,Hebei Province,China） were investigated using static chambers during two consecutive maize growing seasons in the 2008 and 2009.The N 2 O pulse emissions occurred with duration of about 10 days after basal and additional fertilizer applications in the both years.The average N 2 O fluxes from the CK （control plot,without crop,fertilization and irrigation）,NP （chemical N fertilizer）,SN （wheat straw returning plus chemical N fertilizer）,OM- 1/2N （chicken manure plus half chemical N fertilizer） and OMN （chicken manure plus chemical N fertilizer） plots in 2008 were 8.51,72.1,76.6,101,107 ng N/（m 2 ·sec）,respectively,and in 2009 were 33.7,30.0 and 35.0 ng N/（m 2 ·sec） from CK,NP and SN plots,respectively.The emission factors of the applied fertilizer as N 2 O-N （EFs） were 3.8% （2008） and 1.1% （2009） for the NP plot,3.2% （2008） and 1.2% （2009） for the SN plot,and 2.8% and 2.2% in 2008 for the OM-1/2N and OMN plots,respectively.Hydromorphic properties of the investigated soil （with gley） are in favor of denitrification.The large differences of the soil temperature and water-filled pore space （WFPS） between the two maize seasons were suspected to be responsible for the significant yearly variations.Compared with the treatments of NP and SN,chicken manure coupled with compound fertilizer application significantly reduced fertilizer loss rate as N 2 O-N.展开更多
Water regime and nitrogen（N） fertilizer are two important factors impacting greenhouse gases（GHG） emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we condu...Water regime and nitrogen（N） fertilizer are two important factors impacting greenhouse gases（GHG） emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane（CH4） emission compared with continuous flooding, however,the decrement was far lower than the global average level. The N2O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH4 emissions at low level（75 kg N/ha）. But both CH4 and N2O emissions were uninfluenced at the levels of 150 kg N/ha and 225 kg N/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150 kg N/ha. From our results, we recommended that the intermittent irrigation and 150 kg N/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields.展开更多
Aquatic ecosystems have been identified as a globally significant source of nitrous oxide(N_2O) due to continuous active nitrogen involvement, but the processes and influencing factors that control N_2O production are...Aquatic ecosystems have been identified as a globally significant source of nitrous oxide(N_2O) due to continuous active nitrogen involvement, but the processes and influencing factors that control N_2O production are still poorly understood, especially in reservoirs. For that, monthly N_2O variations were monitored in Dongfeng reservoir(DFR)with a mesotrophic condition. The dissolved N_2O concentration in DFR displayed a distinct spatial–temporal pattern but lower than that in the eutrophic reservoirs. During the whole sampling year, N_2O saturation ranging from 144% to 640%, indicating that reservoir acted as source of atmospheric N_2O. N_2O production is induced by the introduction of nitrogen(NO_3^-, NH_4^+) in mesotrophic reservoirs, and is also affected by oxygen level and water temperature. Nitrification was the predominate process for N_2O production in DFR due to well-oxygenated longitudinal water layers.Mean values of estimated N_2O flux from the air–water interface averaged 0.19 μmol m^(-2)h^(-1) with a range of 0.01–0.61 μmol m^(-2)h^(-1). DFR exhibited less N_2O emission flux than that reported in a nearby eutrophic reservoir, but still acted as a moderate N_2O source compared with other reservoirs and lakes worldwide. Annual emissions from the water–air interface of DFR were estimated to be 0.32×10~5 mol N–N_2O, while N_2O degassing from releasing water behind the dam during power generation was nearly five times greater. Hence, N_2O degassing behind the dam should be taken into account for estimation of N_2O emissions from artificial reservoirs, an omission that historically has probably resulted in underestimates. IPCC methodology should consider more specifically N_2O emission estimation in aquatic ecosystems, especially in reservoirs, the default EF5 model will lead to an overestimation.展开更多
Increased precipitation during the vegetation periods was observed in and further predicted for Inner Mongolia. The changes in the associated soil moisture may affect the biosphere-atmosphere exchange of greenhouse ga...Increased precipitation during the vegetation periods was observed in and further predicted for Inner Mongolia. The changes in the associated soil moisture may affect the biosphere-atmosphere exchange of greenhouse gases. Therefore, we set up an irrigation experiment with one watered （W） and one unwatered plot （UW） at a winter-grazed Leymus chinensis-steppe site in the Xilin River catchment, Inner Mongolia. UW only received the natural precipitation of 2005 （129 mm）, whereas W was additionally watered after the precipitation data of 1998 （in total 427 mm）. In the 3-hour resolution, we determined nitrous oxide （N20）, methane （CH4） and carbon dioxide （CO2） fluxes at both plots between May and September 2005, using a fully automated, chamber-based measuring system. N20 fluxes in the steppe were very low, with mean emissions （±s.e.） of 0.9-4-0.5 and 0.7-4-0.5 μg N m^-2 h^-1 at W and UW, respectively. The steppe soil always served as a CH4 sink, with mean fluxes of -24.1-4-3.9 and -31.1-4- 5.3 μg C m^-2 h^-1 at W and UW. Nighttime mean CO2 emissions were 82.6±8.7 and 26.3±1.7 mg C m^-2 h^-1 at W and UW, respectively, coinciding with an almost doubled aboveground plant biomass at W. Our results indicate that the ecosystem CO2 respiration responded sensitively to increased water input during the vegetation period, whereas the effects on CH4 and N2O fluxes were weak, most likely due to the high evapotranspiration and the lack of substrate for N2O producing processes. Based on our results, we hypothesize that with the gradual increase of summertime precipitation in Inner Mongolia, ecosystem CO2 respiration will be enhanced and CH4 uptake by the steppe soils will be lightly inhibited.展开更多
BACKGROUND Nitrous oxide(N2O)has gained increasing popularity as a recreational drug,causing hallucinations,excitation,and psychological dependence.However,side effects have been reported in recent years.Our case repo...BACKGROUND Nitrous oxide(N2O)has gained increasing popularity as a recreational drug,causing hallucinations,excitation,and psychological dependence.However,side effects have been reported in recent years.Our case report proposes a correlation among N2O,pulmonary embolism(PE),and deep vein thrombosis(DVT)and emphasizes the role of homocysteine(Hcy)in thrombotic events.CASE SUMMARY A 29-year-old man with long-term N2O abuse sought evaluation after acute chest pain.A diagnostic workup revealed PE,DVT,and hyperhomocysteinemia.The patient was successfully treated with thrombolytic and anticoagulant therapy.Moreover,his Hcy level decreased and returned to normal after Hcy-lowering therapy.CONCLUSION Chronic N2O abuse might increase the risk of PE and DVT,although there have been few studies previously.展开更多
基金National Natural Science Foundation of China(Project No.:52320105003,Project No.:52303019)the CAS-ANSO Co-funding Research Project(Project No.:CAS-ANSO-CF-2024)+2 种基金the National Key R&D Program of China(Project No.:2023YFC3707201)the Fundamental Research Funds for the Central Universities(Project No.:E3ET1803)China Postdoctoral Science Foundation(Project No:2024T170904)。
文摘The valorization of nitrous oxide(N_(2)O)as an oxygen atom donor presents an attractive opportunity for green chemistry applications,leveraging both its industrial abundance and thermodynamically favorable oxidation potential.However,practical implementation has been constrained by the inherent kinetic inertness and poor coordinating ability of N_(2)O.While prior studies achieved N_(2)O-mediated conversion of aryl halides to phenols,such transformations necessitated stoichiometric chemical reductants and elevated pressure(2 atm),posing challenges in operational safety and process scalability.This study focuses on an electrochemical strategy that enables efficient oxygen atom transfer under ambient pressure through controlled current application.This methodology facilitates the selective transformation of aryl iodides to phenols without external reducing agents,establishing an environmentally benign synthetic pathway.By replacing traditional chemical reductants with electrons as the sole reducing equivalent,our approach addresses critical sustainability challenges in aromatic oxygenation chemistry while maintaining operational simplicity under mild conditions.
基金supported by the National Key R&D Program of China(No.2023YFC3707201)the National Natural Science Foundation of China(No.52320105003)+1 种基金the Informatization Plan of Chinese Academy of Sciences(No.CAS-WX2023PY-0103)the Fundamental Research Funds for the Central Universities(No.E3ET1803).
文摘Nitrous oxide(N_(2)O),as an important gas affecting climate warming,is attracting attention from allwalks of life.This reviewaddresses N_(2)O emissions status in the adipic acid industry,a significant industrial greenhouse gas source.It elucidates the N_(2)O emission mechanism and influencing factors in adipic acid production.It extensively evaluates N_(2)O emission accounting methods,including Intergovernmental Panel on Climate Change(IPCC)Guidelines,World Resources Institute(WRI)Protocol,and others.While the IPCC emission factor method offers simplicity and comparability,it may lack precision for facilities with advanced emission reduction measures.To address this,a combined modeling and monitoring approach is advocated.It scrutinizes modeling methods(statistical techniques,Greenhouse Gas and Air Pollution Interactions and Synergies,and Life-cycle Assessment)and highlights their reliance on specific data and perspectives.It emphasizes the growing importance of on-site monitoring with mid-IR technology.Additionally,it underscores the potential of aircraft-based and satellite remote sensing for comprehensive N_(2)O emissions data.The reviewalso highlights recent advancements in emission mitigation,particularly in adipic acid synthesis techniques,showing substantial potential for N_(2)O reduction.Innovative paradigms and strategies for N_(2)O mitigation in the adipic acid industry are presented,with a focus on achieving nitrogen oxides(NO_(x))-free production.These approaches hold promise for emission reduction,given the high removal efficiency in plant end-of-treatment processes.Various accounting methods,monitoring techniques,and mitigation strategies were integrated and analyzed to provides a comprehensive overview of N_(2)O emissions in the adipic acid industry,with the aim of guiding future research and policy initiatives.
基金The National Natural Science Foundation of China under contract No.41906193the Scientific Research Foundation of Third Institute of Oceanography,Ministry of Natural Resources,under contract No.2019033+2 种基金the Natural Science Foundation of Fujian Province under contract No.2019J05147the Federal Ministry of Education and Research of Germany under contract No.FKZ 03F03F0783Athe National Polar Special Program under contract Nos IRASCC 01-01-02 and IRASCC 02-02.
文摘The global ocean is a major source of the climate-relevant atmospheric trace gas nitrous oxide(N_(2)O).However,an accurate assessment of the global oceanic emissions of N_(2)O is hampered by missing data on dissolved N_(2)O from large regions such as the Southern Ocean.To address this deficit,N_(2)O was measured in the Prydz Bay in February 2015 during the 31st Chinese National Antarctic Research Expedition.N_(2)O concentrations(saturation)in the surface layer were generally low(undersaturation with respect to atmospheric equilibrium)and ranged from 13.3 nmol/L to 16.1 nmol/L(83%–102%)at the time of sampling.A comparison of our observations with archived data revealed that no discernible trend in N_(2)O concentrations in the surface waters of Prydz Bay could be detected for the period between 2006 and 2015.Temperature and salinity changes driven by meltwater input were the predominant controls on N_(2)O concentrations in surface waters.At depth,the distribution of N_(2)O concentrations was dominated by production via nitrification in offshore deep waters and vertical convection in the shelf waters,where concentrations were lower and gradients were less steep.Our results suggest a rather unusual pattern of N_(2)O distribution in the Prydz Bay(low N_(2)O in shelf waters compared with the open ocean),providing important insights into the coastal dynamics of N_(2)O in high-latitude polar regions.
基金supported by the National Natural Science Foundation of China(31572428)。
文摘The objectives of this study which included two experiments were to investigate the effects of dietary inclusion of sorghum grain rich in condensed tannins(CT)(18.9 g kg^(–1)dry matter(DM))on nitrogen(N)metabolism and urine nitrous oxide(N_(2)O)emissions of beef steers.In experiment 1,six Limousin×Luxi crossbreed steers with an initial liveweight of(245.0±18.7)kg were used as experimental animals.Three levels of sorghum grain,i.e.,0,167 and 338 g kg^(–1)DM were included in diets as experimental treatments.The animals and the treatments were randomly assigned to a replicated 3×3 Latin square design.In experiment 2,static incubation technique was used to determine the N_(2)O emissions of the urine samples collected in experiment 1.The results of experiment 1 showed that dietary inclusion of sorghum grain linearly increased the faecal N excretion(P=0.001),the total N excretion(P=0.010)and the faecal N to N intake ratio(P=0.021),but it did not affect the N retention and the N utilization efficiency(P>0.10).The plasma metabolomic data showed that dietary inclusion of sorghum grain increased the relative concentrations of phenolic acid(N1,N5,N10-tris-trans-p-coumaroylspermine and prenyl cis-caffeate)and carnitine(3-hydroxyisovalerylcarnitine and linoelaidyl carnitine).The results also showed that dietary inclusion of sorghum grain linearly increased the urinary urea excretion(P=0.010)and decreased the urinary excretion of purine derivatives(P=0.041)as well as the estimated rumen microbial N supply(P=0.012)based on urinary purine derivatives.The results of experiment 2 showed that including sorghum grain in the diet linearly increased the average concentrations of NH_(4)^(+)-N(P=0.012),NO_(2)^(–)-N(P=0.009),NO_(3)^(-)-N(P=0.001)and the total inorganic N(P<0.001)in the soil enriched with urine samples.The urine sample N_(2)O-N flux(P=0.001),the estimated steer urine N_(2)O-N flux(P=0.021)and the N_(2)O-N to urinary N ratio(P=0.038)linearly increased with increasing inclusion of sorghum grain in the diet.In conclusion,dietary inclusion of sorghum grain containing high CT at 167 and 338 g kg^(–1)DM did not affect the N utilization efficiency of steers but increased the urine N_(2)O-N emissions by 5.7 and 31.4%,respectively.For reducing the N_(2)O emissions to the environment,high levels of sorghum grain should not be included in the diet of steers.
基金supported by the National Natural Science Foundation of China(Nos.52260028,52060022,52260029,and 52160021)the National Key Research and Development Program of China(Nos.2017YFE0114800 and 2019YFC0409200)+1 种基金Inner Mongolia Autonomous Region Science and Technology Plan(No.2021GG0089)personal grant to Guohua Li by China Scholarship Council(CSC).
文摘Eutrophic shallow lakes are generally considered as a contributor to the emission of nitrous oxide(N_(2)O),while regional and global estimates have remained imprecise.This due to a lack of data and insufficient understanding of the multiple contributing factors.This study characterized the spatiotemporal variability in N_(2)O concentrations and N_(2)O diffusive fluxes and the contributing factors in LakeWuliangsuhai,a typical shallow eutrophic and seasonally frozen lake in Inner Mongolia with cold and arid climate.Dissolved N_(2)O concentrations of the lake exhibited a range of 4.5 to 101.2 nmol/L,displaying significant spatiotemporal variations.The lowest and highest concentrations were measured in summer and winter,respectively.The spatial distribution of N_(2)Ofluxwas consistent with that of N_(2)O concentrations.Additionally,the hotspots of N_(2)O emissions were detected within close to the main inflow of lake.The wide spatial and temporal variation in N_(2)O emissions indicate the complexity and its relative importance of factors influencing emissions.N_(2)O emissions in different lake zones and seasons were regulated by diverse factors.Factors influencing the spatial and temporal distribution of N_(2)O concentrations and fluxes were identified as WT,WD,DO,Chl-a,SD and COD.Interestingly,the same factor demonstrated opposing effects on N_(2)O emission in various seasons or zones.This research improves our understanding of N_(2)O emissions in shallow eutrophic lakes in cold and arid areas.
基金This research was supported by the Zhejiang Provincial Natural Science Foundation of China(LR18B060001)Basic Research Project of Sinopec Group(415025)the Fundamental Research Funds for the Central Universities.
文摘Iron-containing zeolites play an important role in the selective oxidation of methane to oxygenates by nitrous oxide.A solid-state ion exchange method is adopted to prepare Fe-MOR zeolite catalysts with different amounts of extra-framework Al.EPR spectra and UV-vis spectra show that the percentage of iron ions in tetrahedral or octahedral coordination increases while those of clustered Fe species decrease by the addition of extra-framework Al species.Nitrous oxide titration reveals that more active Fe centers are formed,which promote the nitrous oxide consumption.The number of active centers in the catalyst with the introduction of extra-framework Al is about four times that of the catalyst without the addition of extra-framework Al.Due to this,there is an increase in the methane conversion,total selectivity and yield of oxygenates.
基金Supported by National"Twelfth Five-Year Plan"of Scientific and Technological Support Plan(No.2011BAD16B04)~~
文摘This paper monitors the differences of early rice yield and the emissions of methane and nitrous oxide in the paddy field, based on the different cultivation technologies（high-yield scattered-planting mode, transplanting mode, farmer-planting mode）. Results suggested that the rice yield by high-yield scattered-planting mode and transplanting mode was significantly higher than farmer-planting mode, and the increase reached 16.4% and 17.7%. The difference of high-yield scattered-planting mode and transplanting mode was insignificant. The potential contributions of the methane amount by these three patterns to the global contribution were all above90%. The emission of methane during the growth period by the high-yield scatteredplanting mode was dramatically lower than that by transplanting mode and farmerplanting mode, while the differences between the high-yield transplanting mode and the farmer mode were insignificant. The changes of global temperature increase and the emission of methane were the same. The greenhouse gas intensity of high-yield scattered-planting mode was the lowest, and the farmer-planting mode was the highest. Therefore, the scattered-planting with reasonable fertilizing method is the most essential way to realize high yield of rice and the reducing the greenhouse gas emission as well.
基金financially supported by the National Natural Science Foundation of China(No.22309067)the Open Project Program of the State Key Laboratory of Materials-Oriented Chemical Engineering,China(No.KL21-05)the Marine Equipment and Technology Institute,Jiangsu University of Science and Technology,China(No.XTCX202404)。
文摘This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.
基金funded by the National Science Centre,Poland,on the basis of the decision number UMO-2020/37/B/ST8/02097supported by the program“Excellence Initiative-Research University”for the AGH University of Krakow(IDUB AGH,No.501.696.7996,Action 4,ID 9880).
文摘Multicomponent Gd_(1−x)Sm_(x)Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)double perovskites are optimized for application in terms of chemical composi-tion and morphology for the use as oxygen electrodes in solid oxide cells.Structural studies of other physicochemical properties are con-ducted on a series of materials obtained by the sol-gel method with different ratios of Gd and Sm cations.It is documented that changing the x value,and the resulting adjustment of the average ionic radius,have a significant impact on the crystal structure,stability,as well as on the total conductivity and thermomechanical properties of the materials,with the best results obtained for the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)composition.Oxygen electrodes are prepared using the selected compound,allowing to obtain low polarization resistance values,such as 0.086Ω·cm^(2)at 800℃.Systematic studies of electrocatalytic activity are conducted using La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(_(0.2))O_(3−δ)as the electrolyte for all electrodes,and Ce_(0.8)Gd_(0.2)O_(2−δ)electrolyte for the best performing Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes.The electrochemical data are analyzed using the distribution of relaxation times method.Also,the influence of the preparation method of the electrode material is in-ve`stigated using the electrospinning technique.Finally,the performance of the Gd_(0.75)Sm_(0.2)5Ba_(0.5)Sr_(0.5)CoCuO_(5+δ)electrodes is tested in a Ni-YSZ(yttria-stabilized zirconia)anode-supported cell with a Ce_(0.8)Gd_(0.2)O_(2−δ)buffer layer,in the fuel cell and electrolyzer operating modes.With the electrospun electrode,a power density of 462 mW·cm^(−2)is obtained at 700℃,with a current density of ca.0.2 A·cm^(−2)at 1.3 V for the electrolysis at the same temperature,indicating better performance compared to the sol-gel-based electrode.
基金financially supported by the National Natural Science Foundation of China(No.12304077)the Natural Science Foundation of Science and Technology Department of Sichuan Province(No.23NSFSC6224)+3 种基金Sichuan Science and Technology Program(No.2024NSFSC0989)the Key Laboratory of Computational Physics of Sichuan Province(No.YBUJSWL-YB-2022-03)the Material Corrosion and Protection Key Laboratory of Sichuan Province(No.2023CL14 and No.2023CL01)the National Innovation Practice Project(No.202411079005S).
文摘Oxygen release and electrolyte decomposition under high voltage endlessly exacerbate interfacial ramifications and structu ral degradation of high energy-density Li-rich layered oxide(LLO),leading to voltage and capacity fading.Herein,the dual-strategy of Cr,B complex coating and local gradient doping is simultaneously achieved on LLO surface by a one-step wet chemical reaction at room temperature.Density functional theory(DFT)calculations prove that stable B-O and Cr-O bonds through the local gradient doping can significantly reduce the high-energy O 2p states of interfacial lattice O,which is also effective for the near-surface lattice O,thus greatly stabilizing the LLO surface,Besides,differential electrochemical mass spectrometry(DEMS)indicates that the Cr_(x)B complex coating can adequately inhibit oxygen release and prevents the migration or dissolution of transition metal ions,including allowing speedy Li^(+)migration,The voltage and capacity fading of the modified cathode(LLO-C_(r)B)are adequately suppressed,which are benefited from the uniformly dense cathode electrolyte interface(CEI)composed of balanced organic/inorganic composition.Therefore,the specific capacity of LLO-CrB after 200 cycles at 1C is 209.3 mA h g^(-1)(with a retention rate of 95.1%).This dual-strategy through a one-step wet chemical reaction is expected to be applied in the design and development of other anionic redox cathode materials.
基金financial support from the Natural Science Foundation of Shandong Province of China(ZR2023ME051,ZR2019MEM020)。
文摘Facilitating anion redox chemistry is an effective strategy to increase the capacity of layered oxides for sodium-ion batteries.Nevertheless,there remains a paucity of literature pertaining to the oxygen redox chemistry of O3-type layered oxide cathode materials.This work systematically investigates the effect of Fe doping on the anionic oxygen redox chemistry and electrochemical reactions in O3-NaNi_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1)O_(2).The results of the density functional theory(DFT)calculations indicate that the electrons of the O 2p occupy a higher energy level.In the ex-situ X-ray photoelectron spectrometer(XPS)of O 1s,the addition of Fe facilitates the lattice oxygen(O^(n-))to exhibit enhanced activity at 4.45 V.The in-situ X-ray diffraction(XRD)demonstrates that the doping of Fe effectively suppresses the Y phase transition at high voltages.Furthermore,the Galvanostatic Intermittent Titration Technique(GITT)data indicate that Fe doping significantly increases the Na~+migration rate at high voltages.Consequently,the substitution of Fe can elevate the cut-off voltage to 4.45 V,thereby facilitating electron migration from O^(2-).The redox of O^(2-)/O^(n-)(n<2)contributes to the overall capacity.O3-Na(Ni_(0.4)Cu_(0.1)Mn_(0.4)Ti_(0.1))_(0.92)Fe_(0.08)O_(2)provides an initial discharge specific capacity of 180.55 mA h g^(-1)and71.6%capacity retention at 0.5 C(1 C=240 mA g^(-1)).This work not only demonstrates the beneficial impact of Fe substitution for promoting the redox activity and reversibility of O^(2-)in 03-type layered oxides,but also guarantees the structural integrity of the cathode materials at high voltages(>4.2 V).It offers a novel avenue for investigating the anionic redox reaction in O3-type layered oxides to design advanced cathode materials.
基金National Key Research and Development Program of China(2020YFA0710302)The Major Research Plan of the National Natural Science Foundation of China(91963206)+2 种基金The National Natural Science Foundation of China(52072169,51972164,51972167,22279053)The Fundamental Research Funds for the Central Universities(14380193)The Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2019ZT08L101).
文摘On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil particles.However,soil particles on the Earth with the similar composition lack such structures and properties.This discrepancy raises a key question whether there is a direct relationship between solar wind irradiation and the alterations in the structure and chemical performance of extraterrestrial materials.To address this question,this work investigates the effects of proton irradiation,simulating solar wind radiation,on the structure and photothermal catalytic properties of the classic catalyst In_(2)O_(3).It reveals that proton irradiation induces structural features in In_(2)O_(3) analogous to those characteristics of solar wind weathering observed in extraterrestrial materials.Furthermore,after proton beam irradiation with an energy of 30 keV and a dose of 3×10^(17) protons·cm^(-2),the methanol production yield of the In_(2)O_(3) catalyst increased to 2.6 times of its preirradiation level,and the methanol selectivity improved to 2.1 times of the original value.This work provides both theoretical and experimental support for the development of high-efficiency,radiation-resistant photothermal catalysts.
基金supported by the National Key Technologies R&D Program of China (2011BAD16B15 and 2012BAD14B03)
文摘Many studies have focused on various agricultural management measures to reduce agricultural nitrous oxide （N2O） emission. However, few studies have investigated soil N2O emissions in intercropping systems in the North China Plain. Thus, we conducted a ifeld experiment to compare N2O emissions under monoculture and maize-legume intercropping systems. In 2010, ifve treatments, including monocultured maize （M）, maize-peanut （MP）, maize-alfalfa （MA）, maize-soybean （MS）, and maize-sweet clover （MSC） intercropping were designed to investigate this issue using the static chamber technique. In 2011, M, MP, and MS remained, and monocultured peanuts （P） and soybean （S） were added to the trial. The results showed that total production of N2O from different treatments ranged from （0.87＆#177;0.12） to （1.17＆#177;0.11） kg ha-1 in 2010, while those ranged from （3.35＆#177;0.30） to （9.10＆#177;2.09） kg ha-1 in 2011. MA and MSC had no signiifcant effect on soil N2O production compared to that of M （P＆lt;0.05）. Cumulative N2O emissions from MP in 2010 were signiifcantly lower than those from M, but the result was the opposite in 2011 （P＆lt;0.05）. MS signiifcantly reduced soil N2O emissions by 25.55 and 48.84%in 2010 and 2011, respectively （P＆lt;0.05）. Soil N2O emissions were signiifcantly correlated with soil water content, soil temperature, nitriifcation potential, soil NH4＋, and soil NO3-content （R2=0.160-0.764, P＆lt;0.01）. A stepwise linear regression analysis indicated that soil N2O release was mainly controlled by the interaction between soil moisture and soil NO3-content （R2=0.828, P＆lt;0.001）. These results indicate that MS had a coincident effect on soil N2O lfux and signiifcantly reduced soil N2O production compared to that of M over two growing seasons.
基金supported by the Shenzhen Science and Technology Development Funding-Fundamental Research Plan (No. JC201006030878A)the Environmental Protection Funding from Human Settlements and Environment Commission of Shenzhen Municipality
文摘Nitrous oxide （N2O） emission during denitrification is receiving intensive attention due to its high potential to cause greenhouse effects. In this study, denitrifiers were acclimated in sequencing batch reactors with methanol or acetate as the electron donor and nitrate as the electron acceptor. The effects of ammonium on NzO emission were examined in batch experiments with various electron donors. With the addition of ammonium, N2O emission increased under all the examined conditions compared to experiments without ammonium addition. With different electron donors, the highest ratio of N2O emission to the removed oxidized nitrogen was 0.70% for methanol, 5.34% for acetate, and 34.79% for polyhydroxybutyrate.
文摘A laboratory incubation experiment was conducted to investigate nitrous oxide(N 2O) emission and reduction in a paddy soil(Stagnic Anthrosol) response to the pretreatment of water regime. The paddy soil was maintained under either air dried(sample D) or submerged(sample F) conditions for 110 d before the soil was adjusted into soil moisture of 20%, 40%, 60%, 80% and 100% water holding capacity(WHC) respectively, and then incubated with or without 10%(v/v) acetylene for 138 h at 25℃. At lower soil water content (≤60% WHC), N 2O emission from the sample F was 2 29 times higher than that from the sample D( P <0 01). While, N 2O emission from the sample F was only 29 and 14 percent of that from the sample D at the soil moisture of 80% and 100% WHC, respectively( P <0 01). The maximal N 2O emissions observed at soil moisture of 80% WHC were about 24 and 186 times higher than the minima obtained at the soil moisture of 20% WHC for the sample F and D, respectively. But at the soil moisture of 80% and 100% WHC, N 2O emission from the sample F with acetylene(F+ACE) was comparable to that of the sample D with acetylene (D+ACE). The results showed that the F sample produced N 2O ability in denitrification was similar to the sample D, however, the sample F was in the better reduction of N 2O to N 2 than the sample D even after the soil moisture was adjusted into the same level of 80% or 100% WHC. Therefore, the pretreatment of water regime influenced the strength and product composition of denitrification and N 2O emission from the paddy soil.
基金supported by the National Natural Science Foundation of China (No. 40830101,20977097, 41075094,21177140)the Special Fund for Environmental Research in the Public Interest (No. 201009001)+1 种基金the National Water Special Project (No. 2008ZX07421-001,2009ZX07210-009)the National Basic Research and the Development Program (973) of China (No. 2010CB732304)
文摘Nitrous oxide （N 2 O） emissions from a maize field in the North China Plain （Wangdu County,Hebei Province,China） were investigated using static chambers during two consecutive maize growing seasons in the 2008 and 2009.The N 2 O pulse emissions occurred with duration of about 10 days after basal and additional fertilizer applications in the both years.The average N 2 O fluxes from the CK （control plot,without crop,fertilization and irrigation）,NP （chemical N fertilizer）,SN （wheat straw returning plus chemical N fertilizer）,OM- 1/2N （chicken manure plus half chemical N fertilizer） and OMN （chicken manure plus chemical N fertilizer） plots in 2008 were 8.51,72.1,76.6,101,107 ng N/（m 2 ·sec）,respectively,and in 2009 were 33.7,30.0 and 35.0 ng N/（m 2 ·sec） from CK,NP and SN plots,respectively.The emission factors of the applied fertilizer as N 2 O-N （EFs） were 3.8% （2008） and 1.1% （2009） for the NP plot,3.2% （2008） and 1.2% （2009） for the SN plot,and 2.8% and 2.2% in 2008 for the OM-1/2N and OMN plots,respectively.Hydromorphic properties of the investigated soil （with gley） are in favor of denitrification.The large differences of the soil temperature and water-filled pore space （WFPS） between the two maize seasons were suspected to be responsible for the significant yearly variations.Compared with the treatments of NP and SN,chicken manure coupled with compound fertilizer application significantly reduced fertilizer loss rate as N 2 O-N.
基金supported by the China Postdoctoral Science Foundation(No.2012M511005)National Key Technology Support Program of China(No.2015BAC02B02)+6 种基金the Agro-scientific Research Programs in Public Interest(No.201303102)National Natural Science Foundation of China(No.31501263)the Postdoctoral Financial Assistance of Heilongjiang Province(No.LBH-Z12232)the Scientific Research Initiation Fund for Introduction of Ph.D Talent of Heilongjiang Academy of Agricultural Sciences(No.201507-14)the State Key Program of China(No.2016YFD0300900)the Major Project of Research and Development of Applied Technology of Heilongjiang Province(No.GA15B101)the Provincial Matching Funds to the National Foundation of Applied Technology Research and Development Program in Heilongjiang Province(No.GX16B002)
文摘Water regime and nitrogen（N） fertilizer are two important factors impacting greenhouse gases（GHG） emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane（CH4） emission compared with continuous flooding, however,the decrement was far lower than the global average level. The N2O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH4 emissions at low level（75 kg N/ha）. But both CH4 and N2O emissions were uninfluenced at the levels of 150 kg N/ha and 225 kg N/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150 kg N/ha. From our results, we recommended that the intermittent irrigation and 150 kg N/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields.
基金financially supported by the National Key Research and Development Program of China through grant 2016YFA0601000the National Major Scientific Research Program Grant No.2013CB956401+1 种基金the National Natural Science Foundation of China through Grants Nos.41325010,41403082,and 41302285the Tianjin Research Program of Application Foundation and Advanced Technology Grant No.14JCQNJC08800
文摘Aquatic ecosystems have been identified as a globally significant source of nitrous oxide(N_2O) due to continuous active nitrogen involvement, but the processes and influencing factors that control N_2O production are still poorly understood, especially in reservoirs. For that, monthly N_2O variations were monitored in Dongfeng reservoir(DFR)with a mesotrophic condition. The dissolved N_2O concentration in DFR displayed a distinct spatial–temporal pattern but lower than that in the eutrophic reservoirs. During the whole sampling year, N_2O saturation ranging from 144% to 640%, indicating that reservoir acted as source of atmospheric N_2O. N_2O production is induced by the introduction of nitrogen(NO_3^-, NH_4^+) in mesotrophic reservoirs, and is also affected by oxygen level and water temperature. Nitrification was the predominate process for N_2O production in DFR due to well-oxygenated longitudinal water layers.Mean values of estimated N_2O flux from the air–water interface averaged 0.19 μmol m^(-2)h^(-1) with a range of 0.01–0.61 μmol m^(-2)h^(-1). DFR exhibited less N_2O emission flux than that reported in a nearby eutrophic reservoir, but still acted as a moderate N_2O source compared with other reservoirs and lakes worldwide. Annual emissions from the water–air interface of DFR were estimated to be 0.32×10~5 mol N–N_2O, while N_2O degassing from releasing water behind the dam during power generation was nearly five times greater. Hence, N_2O degassing behind the dam should be taken into account for estimation of N_2O emissions from artificial reservoirs, an omission that historically has probably resulted in underestimates. IPCC methodology should consider more specifically N_2O emission estimation in aquatic ecosystems, especially in reservoirs, the default EF5 model will lead to an overestimation.
基金the German Research Foundation (DFG, Research UnitNo. 536, "Matter fluxes in grasslands of Inner Mongo-lia as influenced by stocking rate", MAGIM) (BU 1173/6-2)the National Natural Science Foundation of China(NSFC) (Grant Nos. 40425010, 40331014)
文摘Increased precipitation during the vegetation periods was observed in and further predicted for Inner Mongolia. The changes in the associated soil moisture may affect the biosphere-atmosphere exchange of greenhouse gases. Therefore, we set up an irrigation experiment with one watered （W） and one unwatered plot （UW） at a winter-grazed Leymus chinensis-steppe site in the Xilin River catchment, Inner Mongolia. UW only received the natural precipitation of 2005 （129 mm）, whereas W was additionally watered after the precipitation data of 1998 （in total 427 mm）. In the 3-hour resolution, we determined nitrous oxide （N20）, methane （CH4） and carbon dioxide （CO2） fluxes at both plots between May and September 2005, using a fully automated, chamber-based measuring system. N20 fluxes in the steppe were very low, with mean emissions （±s.e.） of 0.9-4-0.5 and 0.7-4-0.5 μg N m^-2 h^-1 at W and UW, respectively. The steppe soil always served as a CH4 sink, with mean fluxes of -24.1-4-3.9 and -31.1-4- 5.3 μg C m^-2 h^-1 at W and UW. Nighttime mean CO2 emissions were 82.6±8.7 and 26.3±1.7 mg C m^-2 h^-1 at W and UW, respectively, coinciding with an almost doubled aboveground plant biomass at W. Our results indicate that the ecosystem CO2 respiration responded sensitively to increased water input during the vegetation period, whereas the effects on CH4 and N2O fluxes were weak, most likely due to the high evapotranspiration and the lack of substrate for N2O producing processes. Based on our results, we hypothesize that with the gradual increase of summertime precipitation in Inner Mongolia, ecosystem CO2 respiration will be enhanced and CH4 uptake by the steppe soils will be lightly inhibited.
文摘BACKGROUND Nitrous oxide(N2O)has gained increasing popularity as a recreational drug,causing hallucinations,excitation,and psychological dependence.However,side effects have been reported in recent years.Our case report proposes a correlation among N2O,pulmonary embolism(PE),and deep vein thrombosis(DVT)and emphasizes the role of homocysteine(Hcy)in thrombotic events.CASE SUMMARY A 29-year-old man with long-term N2O abuse sought evaluation after acute chest pain.A diagnostic workup revealed PE,DVT,and hyperhomocysteinemia.The patient was successfully treated with thrombolytic and anticoagulant therapy.Moreover,his Hcy level decreased and returned to normal after Hcy-lowering therapy.CONCLUSION Chronic N2O abuse might increase the risk of PE and DVT,although there have been few studies previously.
