Background: Nitrogen(N) deposition affects soil greenhouse gas(GHG) emissions, while biochar application reduces GHG emissions in agricultural soils. However, it remains unclear whether biochar amendment can alleviate...Background: Nitrogen(N) deposition affects soil greenhouse gas(GHG) emissions, while biochar application reduces GHG emissions in agricultural soils. However, it remains unclear whether biochar amendment can alleviate the promoting effects of N input on GHG emissions in forest soils. Here, we quantify the separate and combined effects of biochar amendment(0, 20, and 40 t·ha) and N addition(0, 30, 60, and 90 kg N·ha·yr) on soil GHG fluxes in a long-term field experiment at a Moso bamboo(Phyllostachys edulis) plantation.Results: Low and moderate N inputs(≤60 kg N·ha·yr) significantly increase mean annual soil carbon dioxide(CO) and nitrous oxide(NO) emissions by 17.0%–25.4% and 29.8%–31.2%, respectively, while decreasing methane(CH) uptake by 12.4%–15.9%, leading to increases in the global warming potential(GWP) of soil CHand NO fluxes by 32.4%–44.0%. Moreover, N addition reduces soil organic carbon(C;SOC) storage by 0.2%–6.5%. Compared to the control treatment, biochar amendment increases mean annual soil CO2emissions, CHuptake, and SOC storage by 18.4%–25.4%, 7.6%–15.8%, and 7.1%–13.4%, respectively, while decreasing NO emissions by 17.6%–19.2%, leading to a GWP decrease of 18.4%–21.4%. Biochar amendments significantly enhance the promoting effects of N addition on soil COemissions, while substantially offsetting the promotion of N2O emissions, inhibition of CHuptake, and decreased SOC storage, resulting in a GWP decrease of 9.1%–30.3%.Additionally, soil COand CHfluxes are significantly and positively correlated with soil microbial biomass C(MBC) and pH. Meanwhile, NO emissions have a significant and positive correlation with soil MBC and a negative correlation with pH.Conclusions: Biochar amendment can increase SOC storage and offset the enhanced GWP mediated by elevated N deposition and is, thus, a potential strategy for increasing soil C sinks and decreasing GWPs of soil CHand NO under increasing atmospheric N deposition in Moso bamboo plantations.展开更多
In the face of global warming and increasing impervious surfaces,quantifying the change of climate potential productivity(CPP)is of great significance for the food production planning.Targeting the Dongting Lake Basin...In the face of global warming and increasing impervious surfaces,quantifying the change of climate potential productivity(CPP)is of great significance for the food production planning.Targeting the Dongting Lake Basin,which is a key area for food production in China,this paper uses meteorological data,as well as Climate Change Initiative Land Cover,and Shuttle Radar Topography Mission digital elevation model to investigate the CPP and its changes from 2000 to 2020.The suitability of land for cultivation(SLC),and the land use/land cover change(LUCC)are also considered.The results showed that the CPP varied from 9,825 to 20,895 kg ha^(-1).Even though the newly added impervious surfaces indirectly resulted in the decrease of CPP by of 9.81×10~8 kg,overall,the CPP increased at an average rate of 83.7 kg ha^(-1)a^(-1).Global warming is the strongest driver behind CPP increase,and CPP has played an important role in the conversions between cultivated land and other land types.The structure of land types tends to be optimized against this challenge.展开更多
Tropical cyclone heat potential （TCHP） in the ocean can affect tropical cyclone intensity and intensification. In this paper, TCHP change under global warming is presented based on 35 models from CMIP5 （Coupled Mod...Tropical cyclone heat potential （TCHP） in the ocean can affect tropical cyclone intensity and intensification. In this paper, TCHP change under global warming is presented based on 35 models from CMIP5 （Coupled Model Intercomparison Project, Phase 5）. As the upper ocean warms up, the TCHP of the global ocean is projected to increase by 140.6% in the 21st century under the RCP4.5 （＋4.5 W m 2 Representative Concentration Pathway） scenario, The increase is particularly significant in the western Pacific, northwestern Indian and western tropical Atlantic oceans. The increase of TCHP results from the ocean temperature warming above the depth of the 26~C isotherm （D26）, the deepening of D26, and the horizontal area expansion of SST above 26~C. Their contributions are 69.4%, 22.5% and 8.1%, respectively. Further, a suite of numerical experiments with an Ocean General Circulation Model （OGCM） is conducted to investigate the relative importance of wind stress and buoyancy forcing to the TCHP change under global warming. Results show that sea surface warming is the dominant forcing for the TCHP change, while wind stress and sea surface salinity change are secondary.展开更多
Perfluorocarbon gas is widely used in the semiconductor industry.However,perfluorocarbon has a negative effect on the global environment owing to its high global warming potential(GWP) value.An alternative solution is...Perfluorocarbon gas is widely used in the semiconductor industry.However,perfluorocarbon has a negative effect on the global environment owing to its high global warming potential(GWP) value.An alternative solution is essential.Therefore,we evaluated the possibility of replacing conventional perfluorocarbon etching gases such as CHF_3 with C_6F_(12)O,which has a low GWP and is in a liquid state at room temperature.In this study,silicon oxynitride(SiON) films were plasma-etched using inductively coupled CF4+C_6F_(12)O+O_2 mixed plasmas.Subsequently,the etching characteristics of the film,such as etching rate,etching profile,selectivity over Si,and photoresist,were investigated.A double Langmuir probe was used and optical emission spectroscopy was performed for plasma diagnostics.In addition,a contact angle goniometer and x-ray photoelectron spectroscope were used to confirm the change in the surface properties of the etched SiON film surface.Consequently,the etching characteristics of the C_6F_(12)O mixed plasma exhibited a lower etching rate,higher SiON/Si selectivity,lower plasma damage,and more vertical etched profiles than the conventional CHF_3 mixed plasma.In addition,the C_6F_(12)O gas can be recovered in the liquid state,thereby decreasing global warming.These results confirmed that the C_6F_(12)O precursor can sufficiently replace the conventional etching gas.展开更多
Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional pr...Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate warming.In this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations.To achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV classification.We find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and precipitation.Notably,we observe an unexpected transition between tundra and savanna despite their geographical distance.The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each group.Indeed,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate.The spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.展开更多
According to climatic, hydrological, soil and vegetation data from671 stations in China, 12 temperate zones contains 45 natural regions areidentified. In this paper, methods like migration of crop distribution ,...According to climatic, hydrological, soil and vegetation data from671 stations in China, 12 temperate zones contains 45 natural regions areidentified. In this paper, methods like migration of crop distribution , potentialproductivity, and dynamic modelling are used to research changs of naturalzones and natural regions of eco-envirotunent.展开更多
The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while tre...The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food chain.However,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(LCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day.The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,respectively.The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more power.The main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).展开更多
The Tropical Cyclone Genesis Potential Index （GPI） was employed to investigate possible impacts of global warming on tropical cyclone genesis over the western North Pacific （WNP）. The outputs of 20th century clima...The Tropical Cyclone Genesis Potential Index （GPI） was employed to investigate possible impacts of global warming on tropical cyclone genesis over the western North Pacific （WNP）. The outputs of 20th century climate simulation by eighteen GCMs were used to evaluate the models＇ ability to reproduce tropical cyclone genesis via the GPI. The GCMs were found in general to reasonably reproduce the observed spatial distribution of genesis. Some of the models also showed ability in capturing observed temporal variation. Based on the evaluation, the models （CGCM3.1-T47 and IPSL-CM4） found to perform best when reproducing both spatial and temporal features were chosen to project future GPI. Results show that both of these models project an upward trend of the GPI under the SRES A2 scenario, however the rate of increase differs between them.展开更多
Tropical cyclone （TC） genesis over the western North Pacific （WNP） is analyzed using 23 CMIP5 （Coupled Model Intercomparison Project Phase 5） models and reanalysis datasets. The models are evaluated according to...Tropical cyclone （TC） genesis over the western North Pacific （WNP） is analyzed using 23 CMIP5 （Coupled Model Intercomparison Project Phase 5） models and reanalysis datasets. The models are evaluated according to TC genesis potential index （GPI）. The spatial and temporal variations of the GPI are first calculated using three atmospheric reanalysis datasets （ERA-Interim, NCEP/NCAR Reanalysis- 1, and NCEP/DOE Reanalysis-2）. Spatial distributions of July-October-mean TC frequency based on the GPI from ERA-interim are more consistent with observed ones derived from IBTrACS global TC data. So, the ERA-interim reanalysis dataset is used to examine the CMIP5 models in terms of reproducing GPI during the period 1982-2005. Although most models possess deficiencies in reproducing the spatial distribution of the GPI, their multi- model ensemble （MME） mean shows a reasonable climatological GPI pattern characterized by a high GPI zone along 20°N in the WNP. There was an upward trend of TC genesis frequency during 1982 to 1998, followed by a downward trend. Both MME results and reanalysis data can represent a robust increasing trend during 1982-1998, but the models cannot simulate the downward trend after 2000. Analysis based on future projection experiments shows that the GPI exhibits no significant change in the first half of the 21st century, and then starts to decrease at the end of the 21st century under the representative concentration pathway （RCP） 2.6 scenario. Under the RCP8.5 scenario, the GPI shows an increasing trend in the vicinity of 20°N, indicating more TCs could possibly be expected over the WNP under future global warming.展开更多
We developed two radiation parameterizations with different resolutions （17-band and 998-band） for perfluorocarbons （PFCs） and sulfur hexafluoride （SF6） using the updated High-resolution Transmission Molecular A...We developed two radiation parameterizations with different resolutions （17-band and 998-band） for perfluorocarbons （PFCs） and sulfur hexafluoride （SF6） using the updated High-resolution Transmission Molecular Absorption （HITRAN） 2004 database and the correlated k-distribution method. We analyzed the impacts of the two radiation schemes on heating rates. Then we studied their instantaneous radiative efficiency, stratospheric adjusted radiative efficiency, global warming potential （GWP）, and global temperature potential （GTP）, for both clear- and all-sky conditions using a high-resolution radiation scheme. We found that the stratosphere-adjusted radiative efficiencies of C2F6, CF4, and SF6 for the whole sky were 0.346, 0.098, and 0.680 W m^-2 ppbv^-1, respectively. Radiative forcing from the industrial revolution to 2005 was 0.001, 0.007, and 0.004 W m^-2, respectively; and was predicted to rise to 0.008, 0.036, and 0.037 W m^-2, respectively, by 2100, according to emission scenarios provided by the IPCC. The GWPs of C2F6, CF4, and SF6 are 17035, 7597, and 31298, respectively, for a time horizon of 100 years relative to CO2. Their GTPs of pulse and sustained emissions, GTPv and GTPs, are 22468, 10052, and 40935 and 16498, 7355, and 30341, respectively, for a 100-year time horizon.展开更多
Unanticipated sabotage of two underwater pipelines in the Baltic Sea(Nord Stream 1 and 2)happened on 26September 2022.Massive quantities of natural gas,primarily methane,were released into the atmosphere,which lasted ...Unanticipated sabotage of two underwater pipelines in the Baltic Sea(Nord Stream 1 and 2)happened on 26September 2022.Massive quantities of natural gas,primarily methane,were released into the atmosphere,which lasted for about one week.As a more powerful greenhouse gas than CO_(2),the potential climatic impact of methane is a global concern.Using multiple methods and datasets,a recent study reported a relatively accurate magnitude of the leaked methane at 0.22±0.03 million tons(Mt),which was lower than the initial estimate in the immediate aftermath of the event.Under an energy conservation framework used in IPCC AR6,we derived a negligible increase in global surface air temperature of 1.8×10^(-5)℃ in a 20-year time horizon caused by the methane leaks with an upper limit of 0.25 Mt.Although the resultant warming from this methane leak incident was minor,future carbon release from additional Earth system feedbacks,such as thawing permafrost,and its impact on the methane mitigation pathways of the Paris Agreement,warrants investigation.展开更多
By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the mode...By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the model with the observed data indicated that the model can simulate both the crop growth processes and emissions of CH4 and N2O accurately. Some nu-merical analyses were made to identify the impacts of different fertilizer application on assimilation of CO2 and emissions of CH4 and N2O, and the transformation principle of the composite global warming potential. Based on the results of the numerical analysis, the source-sink alternation of composite global warming potential in the paddy ecosystem was discovered, and some new con-ceptions of fertilizer index such as maximum-sink fertilizer, zero-emission fertilizer are put forward in this paper. The fertilizer scheme for Yangtze Delta was proposed to provide the important scien-tific basis for a sustainable agriculture in this region.展开更多
This paper presents a theoretical method to calculate the minimum inerting concentration(MIC)of binary and ternary blends(refrigerants)that are used in small refrigeration systems.MIC is the concentration of the dilut...This paper presents a theoretical method to calculate the minimum inerting concentration(MIC)of binary and ternary blends(refrigerants)that are used in small refrigeration systems.MIC is the concentration of the dilutant which makes the flammable mixture into just non-flammable(at non-zero quenching potential).In this study,the refrigerant safety parameters such as flammability,Global Warming Potential(GWP)and performance(COP)are analyzed for twelve binary and thirteen ternary blends containing one flammable and two nonflammable(dilutant)components.Flammability investigation was carried out with the hydrocarbon refrigerants R290,R600,R600a each mixed with dilutants R227ea,R125,R245fa,R13I1 and R134a at different concentrations respectively.Two methods,thermal balance method(TBM)and modified thermal balanced method(MTBM),are used to estimate the MIC(which decides the flammable zone).Thirteen ternary blends were identified based on the MIC values estimated using MTBM.In the case of ternary blends,it was observed that the non-flammable zone is high for the compositions of the Mixture G,Mixture H and Mixture I.It was also estimated that the COPs of the proposed mixtures M22,M24,M25 and M27 are 4%greater than the COP of R134a(for the same operating conditions).Further,it was also understood that the corresponding GWP value is reduced by 90%to 97%for the mixtures(M21,M22,M24,M25 and M27)when compared to R134a(GWP=1300).Therefore,out of the thirteen proposed ternary mixtures(M15 to M27),the mixtures(M21,M22,M24,M25 and M27)are safe in terms of flammability,GWP and possess reasonable COP which can be a potential alternative refrigerant mixture to R134a in small refrigeration systems.展开更多
Due to the large amount of greenhouse gas(GHG)emissions and the high dependence on fossil energy,the aviation industry has attracted a lot of attention for emission reduction and sustainable development.Biomass is a g...Due to the large amount of greenhouse gas(GHG)emissions and the high dependence on fossil energy,the aviation industry has attracted a lot of attention for emission reduction and sustainable development.Biomass is a green and sustainable renewable resource,and its chemical conversion to produce bio-jet fuel is considered to be an effective way to replace fossil jet fuel and achieve emission reduction.In this study,the cradle-to-grave life cycle analysis is conducted for three bio-jet fuel conversion pathways,including biomass aqueous phase reforming(APR),hydrogenated esters and fatty acids(HEFA),and hydrothermal liquefaction(HTL).Compared with fossil jet fuels,the three bio-jet fuels have a great advantage on global warming potential(GWP),contributing 29.2,43.6 and 51.2 g CO_(2)-eq/MJ respectively.In general,as a relatively new bio-jet fuel conversion technology,the technology of aqueous phase reforming has minimal environmental impact.If the barriers of raw material availability and economy could be broken down,bio-jet fuel will have great development potential in replacing fossil jet fuel and realizing sustainable development.展开更多
As concerns about climate change and carbon emissions continue to rise, many companies and organizations are eager to assess their “carbon footprint” to understand their impact on this global challenge. In the realm...As concerns about climate change and carbon emissions continue to rise, many companies and organizations are eager to assess their “carbon footprint” to understand their impact on this global challenge. In the realm of oil production, the environmental consequences can be quite serious, leading to issues like air pollution and heightened global warming potential (GWP) due to increased greenhouse gases (GHG). This study investigates the greenhouse gas (GHG) emissions associated with crude oil and natural gas production at Khalda Petroleum’s sites in Egypt’s western desert. Activities contributing to emissions were categorized by operational boundaries—Scopes 1, 2, and 3—and their carbon footprints were quantified. Key emission sources were identified, with gas flaring and diesel consumption emerging as major contributors, while water supply and refrigerants had minimal impact. Linear relationships revealed strong positive correlations between fuel use, flaring, and venting activities, and GHG emissions, with R2 values close to 1. Polynomial relationships highlighted the influence of device efficiency on emissions, suggesting that optimizing combustion and refrigerant systems is critical for reduction. Recommendations include adopting advanced flaring technologies, switching to cleaner fuels, enhancing equipment efficiency, and integrating renewable energy sources. These strategies aim to minimize emissions while maintaining operational efficiency, aligning Khalda Petroleum with global sustainability standards. Continuous monitoring, employee training, and stakeholder collaboration are emphasized as essential components for long-term success.展开更多
基金sponsored by the National Natural Science Foundation of China,China(Grant Nos.31470529,32125027)Zhejiang A&F University Research and Development Fund,China(Nos.2022LFR006,2021LFR060).
文摘Background: Nitrogen(N) deposition affects soil greenhouse gas(GHG) emissions, while biochar application reduces GHG emissions in agricultural soils. However, it remains unclear whether biochar amendment can alleviate the promoting effects of N input on GHG emissions in forest soils. Here, we quantify the separate and combined effects of biochar amendment(0, 20, and 40 t·ha) and N addition(0, 30, 60, and 90 kg N·ha·yr) on soil GHG fluxes in a long-term field experiment at a Moso bamboo(Phyllostachys edulis) plantation.Results: Low and moderate N inputs(≤60 kg N·ha·yr) significantly increase mean annual soil carbon dioxide(CO) and nitrous oxide(NO) emissions by 17.0%–25.4% and 29.8%–31.2%, respectively, while decreasing methane(CH) uptake by 12.4%–15.9%, leading to increases in the global warming potential(GWP) of soil CHand NO fluxes by 32.4%–44.0%. Moreover, N addition reduces soil organic carbon(C;SOC) storage by 0.2%–6.5%. Compared to the control treatment, biochar amendment increases mean annual soil CO2emissions, CHuptake, and SOC storage by 18.4%–25.4%, 7.6%–15.8%, and 7.1%–13.4%, respectively, while decreasing NO emissions by 17.6%–19.2%, leading to a GWP decrease of 18.4%–21.4%. Biochar amendments significantly enhance the promoting effects of N addition on soil COemissions, while substantially offsetting the promotion of N2O emissions, inhibition of CHuptake, and decreased SOC storage, resulting in a GWP decrease of 9.1%–30.3%.Additionally, soil COand CHfluxes are significantly and positively correlated with soil microbial biomass C(MBC) and pH. Meanwhile, NO emissions have a significant and positive correlation with soil MBC and a negative correlation with pH.Conclusions: Biochar amendment can increase SOC storage and offset the enhanced GWP mediated by elevated N deposition and is, thus, a potential strategy for increasing soil C sinks and decreasing GWPs of soil CHand NO under increasing atmospheric N deposition in Moso bamboo plantations.
基金funded by the National Natural Science Foundation of China(Grant No.72174211)the Natural Science Foundation of Hunan Province(Grant No.2023JJ30693)。
文摘In the face of global warming and increasing impervious surfaces,quantifying the change of climate potential productivity(CPP)is of great significance for the food production planning.Targeting the Dongting Lake Basin,which is a key area for food production in China,this paper uses meteorological data,as well as Climate Change Initiative Land Cover,and Shuttle Radar Topography Mission digital elevation model to investigate the CPP and its changes from 2000 to 2020.The suitability of land for cultivation(SLC),and the land use/land cover change(LUCC)are also considered.The results showed that the CPP varied from 9,825 to 20,895 kg ha^(-1).Even though the newly added impervious surfaces indirectly resulted in the decrease of CPP by of 9.81×10~8 kg,overall,the CPP increased at an average rate of 83.7 kg ha^(-1)a^(-1).Global warming is the strongest driver behind CPP increase,and CPP has played an important role in the conversions between cultivated land and other land types.The structure of land types tends to be optimized against this challenge.
基金supported by the National Basic Research Program of China (Grant No. 2012CB 955601)the National Natural Science Foundation of China (Grant Nos. 41206021 and 41125019)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA11010103)
文摘Tropical cyclone heat potential （TCHP） in the ocean can affect tropical cyclone intensity and intensification. In this paper, TCHP change under global warming is presented based on 35 models from CMIP5 （Coupled Model Intercomparison Project, Phase 5）. As the upper ocean warms up, the TCHP of the global ocean is projected to increase by 140.6% in the 21st century under the RCP4.5 （＋4.5 W m 2 Representative Concentration Pathway） scenario, The increase is particularly significant in the western Pacific, northwestern Indian and western tropical Atlantic oceans. The increase of TCHP results from the ocean temperature warming above the depth of the 26~C isotherm （D26）, the deepening of D26, and the horizontal area expansion of SST above 26~C. Their contributions are 69.4%, 22.5% and 8.1%, respectively. Further, a suite of numerical experiments with an Ocean General Circulation Model （OGCM） is conducted to investigate the relative importance of wind stress and buoyancy forcing to the TCHP change under global warming. Results show that sea surface warming is the dominant forcing for the TCHP change, while wind stress and sea surface salinity change are secondary.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP)the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20172010105910)。
文摘Perfluorocarbon gas is widely used in the semiconductor industry.However,perfluorocarbon has a negative effect on the global environment owing to its high global warming potential(GWP) value.An alternative solution is essential.Therefore,we evaluated the possibility of replacing conventional perfluorocarbon etching gases such as CHF_3 with C_6F_(12)O,which has a low GWP and is in a liquid state at room temperature.In this study,silicon oxynitride(SiON) films were plasma-etched using inductively coupled CF4+C_6F_(12)O+O_2 mixed plasmas.Subsequently,the etching characteristics of the film,such as etching rate,etching profile,selectivity over Si,and photoresist,were investigated.A double Langmuir probe was used and optical emission spectroscopy was performed for plasma diagnostics.In addition,a contact angle goniometer and x-ray photoelectron spectroscope were used to confirm the change in the surface properties of the etched SiON film surface.Consequently,the etching characteristics of the C_6F_(12)O mixed plasma exhibited a lower etching rate,higher SiON/Si selectivity,lower plasma damage,and more vertical etched profiles than the conventional CHF_3 mixed plasma.In addition,the C_6F_(12)O gas can be recovered in the liquid state,thereby decreasing global warming.These results confirmed that the C_6F_(12)O precursor can sufficiently replace the conventional etching gas.
基金funded by the National Natural Science Foundation of China(grants No.30960264,31160475 and 42071258)Open Research Fund of TPESER(grant No.TPESER202208)+2 种基金Special Fund for Basic Scientific Research of Central Colleges,Chang’an University,China(grant No.300102353501)Natural Science Foundation of Gansu Province,China(grant No.22JR5RA857)Higher Education Novel Foundation of Gansu Province,China(grant No.2021B-130)。
文摘Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate warming.In this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations.To achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV classification.We find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and precipitation.Notably,we observe an unexpected transition between tundra and savanna despite their geographical distance.The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each group.Indeed,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate.The spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.
文摘According to climatic, hydrological, soil and vegetation data from671 stations in China, 12 temperate zones contains 45 natural regions areidentified. In this paper, methods like migration of crop distribution , potentialproductivity, and dynamic modelling are used to research changs of naturalzones and natural regions of eco-envirotunent.
基金supported by the National Key Research and Development Program of China(No.2018YFD1100600)Shanghai Municipal Government State-Owned Assets Supervision and Administration Commission(No.2022028)。
文摘The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment option.It can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food chain.However,the performance of this technology in terms of its environmental impacts is still unclear,particularly with regards to global warming potential(GWP).This study used a life cycle assessment(LCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per day.The LCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,respectively.The greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more power.The main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).
基金supported by the Chinese Academy of Sciences under (Grant Nos.KZCX2-YW-Q1-02 and KZCX2-YW-Q11-05)the Major State Basic Research Development Program of China (973 Pro-gram) (Grant No.2009CB421407)the National Natural Science Foundation of China (Grant Nos. 40631005,40775049, and 40805029)
文摘The Tropical Cyclone Genesis Potential Index （GPI） was employed to investigate possible impacts of global warming on tropical cyclone genesis over the western North Pacific （WNP）. The outputs of 20th century climate simulation by eighteen GCMs were used to evaluate the models＇ ability to reproduce tropical cyclone genesis via the GPI. The GCMs were found in general to reasonably reproduce the observed spatial distribution of genesis. Some of the models also showed ability in capturing observed temporal variation. Based on the evaluation, the models （CGCM3.1-T47 and IPSL-CM4） found to perform best when reproducing both spatial and temporal features were chosen to project future GPI. Results show that both of these models project an upward trend of the GPI under the SRES A2 scenario, however the rate of increase differs between them.
基金supported by the National Basic Research Program of China(973 Program)(Grant No.2013CB430304)the Scientific Research Foundation of the First Institute of Oceanography+3 种基金the State Oceanic Administration(Grant No.GY0213G19)the National Natural Science Foundation of China(Grant Nos.41205026 and41206026)supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA11010104)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.SQ201208)
文摘Tropical cyclone （TC） genesis over the western North Pacific （WNP） is analyzed using 23 CMIP5 （Coupled Model Intercomparison Project Phase 5） models and reanalysis datasets. The models are evaluated according to TC genesis potential index （GPI）. The spatial and temporal variations of the GPI are first calculated using three atmospheric reanalysis datasets （ERA-Interim, NCEP/NCAR Reanalysis- 1, and NCEP/DOE Reanalysis-2）. Spatial distributions of July-October-mean TC frequency based on the GPI from ERA-interim are more consistent with observed ones derived from IBTrACS global TC data. So, the ERA-interim reanalysis dataset is used to examine the CMIP5 models in terms of reproducing GPI during the period 1982-2005. Although most models possess deficiencies in reproducing the spatial distribution of the GPI, their multi- model ensemble （MME） mean shows a reasonable climatological GPI pattern characterized by a high GPI zone along 20°N in the WNP. There was an upward trend of TC genesis frequency during 1982 to 1998, followed by a downward trend. Both MME results and reanalysis data can represent a robust increasing trend during 1982-1998, but the models cannot simulate the downward trend after 2000. Analysis based on future projection experiments shows that the GPI exhibits no significant change in the first half of the 21st century, and then starts to decrease at the end of the 21st century under the representative concentration pathway （RCP） 2.6 scenario. Under the RCP8.5 scenario, the GPI shows an increasing trend in the vicinity of 20°N, indicating more TCs could possibly be expected over the WNP under future global warming.
基金supported by National Natural Science Foundation of China (Grant No. 40775006)National Basic Research Program of Chnia (Grant No. 2010CB955703)the Special Foundation for Climate Change (Grant No. 2010-2200509)
文摘We developed two radiation parameterizations with different resolutions （17-band and 998-band） for perfluorocarbons （PFCs） and sulfur hexafluoride （SF6） using the updated High-resolution Transmission Molecular Absorption （HITRAN） 2004 database and the correlated k-distribution method. We analyzed the impacts of the two radiation schemes on heating rates. Then we studied their instantaneous radiative efficiency, stratospheric adjusted radiative efficiency, global warming potential （GWP）, and global temperature potential （GTP）, for both clear- and all-sky conditions using a high-resolution radiation scheme. We found that the stratosphere-adjusted radiative efficiencies of C2F6, CF4, and SF6 for the whole sky were 0.346, 0.098, and 0.680 W m^-2 ppbv^-1, respectively. Radiative forcing from the industrial revolution to 2005 was 0.001, 0.007, and 0.004 W m^-2, respectively; and was predicted to rise to 0.008, 0.036, and 0.037 W m^-2, respectively, by 2100, according to emission scenarios provided by the IPCC. The GWPs of C2F6, CF4, and SF6 are 17035, 7597, and 31298, respectively, for a time horizon of 100 years relative to CO2. Their GTPs of pulse and sustained emissions, GTPv and GTPs, are 22468, 10052, and 40935 and 16498, 7355, and 30341, respectively, for a 100-year time horizon.
基金supported by the National Key Research and Development Program(Grant No.2017YFA0603503)the National Natural Science Foundation of China(Grant No.41605057)。
文摘Unanticipated sabotage of two underwater pipelines in the Baltic Sea(Nord Stream 1 and 2)happened on 26September 2022.Massive quantities of natural gas,primarily methane,were released into the atmosphere,which lasted for about one week.As a more powerful greenhouse gas than CO_(2),the potential climatic impact of methane is a global concern.Using multiple methods and datasets,a recent study reported a relatively accurate magnitude of the leaked methane at 0.22±0.03 million tons(Mt),which was lower than the initial estimate in the immediate aftermath of the event.Under an energy conservation framework used in IPCC AR6,we derived a negligible increase in global surface air temperature of 1.8×10^(-5)℃ in a 20-year time horizon caused by the methane leaks with an upper limit of 0.25 Mt.Although the resultant warming from this methane leak incident was minor,future carbon release from additional Earth system feedbacks,such as thawing permafrost,and its impact on the methane mitigation pathways of the Paris Agreement,warrants investigation.
基金This work was supported by the National Natural Science Foundation of China(Grant No.49899270).
文摘By coupling the biogeochemical model with plant ecological model, a model was established to reveal the principle of the composite global warming potential transformation in the paddy ecosystem. Validation of the model with the observed data indicated that the model can simulate both the crop growth processes and emissions of CH4 and N2O accurately. Some nu-merical analyses were made to identify the impacts of different fertilizer application on assimilation of CO2 and emissions of CH4 and N2O, and the transformation principle of the composite global warming potential. Based on the results of the numerical analysis, the source-sink alternation of composite global warming potential in the paddy ecosystem was discovered, and some new con-ceptions of fertilizer index such as maximum-sink fertilizer, zero-emission fertilizer are put forward in this paper. The fertilizer scheme for Yangtze Delta was proposed to provide the important scien-tific basis for a sustainable agriculture in this region.
文摘This paper presents a theoretical method to calculate the minimum inerting concentration(MIC)of binary and ternary blends(refrigerants)that are used in small refrigeration systems.MIC is the concentration of the dilutant which makes the flammable mixture into just non-flammable(at non-zero quenching potential).In this study,the refrigerant safety parameters such as flammability,Global Warming Potential(GWP)and performance(COP)are analyzed for twelve binary and thirteen ternary blends containing one flammable and two nonflammable(dilutant)components.Flammability investigation was carried out with the hydrocarbon refrigerants R290,R600,R600a each mixed with dilutants R227ea,R125,R245fa,R13I1 and R134a at different concentrations respectively.Two methods,thermal balance method(TBM)and modified thermal balanced method(MTBM),are used to estimate the MIC(which decides the flammable zone).Thirteen ternary blends were identified based on the MIC values estimated using MTBM.In the case of ternary blends,it was observed that the non-flammable zone is high for the compositions of the Mixture G,Mixture H and Mixture I.It was also estimated that the COPs of the proposed mixtures M22,M24,M25 and M27 are 4%greater than the COP of R134a(for the same operating conditions).Further,it was also understood that the corresponding GWP value is reduced by 90%to 97%for the mixtures(M21,M22,M24,M25 and M27)when compared to R134a(GWP=1300).Therefore,out of the thirteen proposed ternary mixtures(M15 to M27),the mixtures(M21,M22,M24,M25 and M27)are safe in terms of flammability,GWP and possess reasonable COP which can be a potential alternative refrigerant mixture to R134a in small refrigeration systems.
基金supported by the National Key R&D Program of China(2018YFB1501500).
文摘Due to the large amount of greenhouse gas(GHG)emissions and the high dependence on fossil energy,the aviation industry has attracted a lot of attention for emission reduction and sustainable development.Biomass is a green and sustainable renewable resource,and its chemical conversion to produce bio-jet fuel is considered to be an effective way to replace fossil jet fuel and achieve emission reduction.In this study,the cradle-to-grave life cycle analysis is conducted for three bio-jet fuel conversion pathways,including biomass aqueous phase reforming(APR),hydrogenated esters and fatty acids(HEFA),and hydrothermal liquefaction(HTL).Compared with fossil jet fuels,the three bio-jet fuels have a great advantage on global warming potential(GWP),contributing 29.2,43.6 and 51.2 g CO_(2)-eq/MJ respectively.In general,as a relatively new bio-jet fuel conversion technology,the technology of aqueous phase reforming has minimal environmental impact.If the barriers of raw material availability and economy could be broken down,bio-jet fuel will have great development potential in replacing fossil jet fuel and realizing sustainable development.
文摘As concerns about climate change and carbon emissions continue to rise, many companies and organizations are eager to assess their “carbon footprint” to understand their impact on this global challenge. In the realm of oil production, the environmental consequences can be quite serious, leading to issues like air pollution and heightened global warming potential (GWP) due to increased greenhouse gases (GHG). This study investigates the greenhouse gas (GHG) emissions associated with crude oil and natural gas production at Khalda Petroleum’s sites in Egypt’s western desert. Activities contributing to emissions were categorized by operational boundaries—Scopes 1, 2, and 3—and their carbon footprints were quantified. Key emission sources were identified, with gas flaring and diesel consumption emerging as major contributors, while water supply and refrigerants had minimal impact. Linear relationships revealed strong positive correlations between fuel use, flaring, and venting activities, and GHG emissions, with R2 values close to 1. Polynomial relationships highlighted the influence of device efficiency on emissions, suggesting that optimizing combustion and refrigerant systems is critical for reduction. Recommendations include adopting advanced flaring technologies, switching to cleaner fuels, enhancing equipment efficiency, and integrating renewable energy sources. These strategies aim to minimize emissions while maintaining operational efficiency, aligning Khalda Petroleum with global sustainability standards. Continuous monitoring, employee training, and stakeholder collaboration are emphasized as essential components for long-term success.
