Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assesse...Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assessed likely range of equilibrium climate sensitivity(ECS)and the climatological precipitation performance,the authors constrain the CMIP6(phase 6 of the Coupled Model Intercomparison Project)model projection of summer precipitation and water availability over the TP.The best estimates of precipitation changes are 0.24,0.25,and 0.45 mm d^(−1)(5.9%,6.1%,and 11.2%)under the Shared Socioeconomic Pathway(SSP)scenarios of SSP1–2.6,SSP2–4.5,and SSP5–8.5 from 2050–2099 relative to 1965–2014,respectively.The corresponding constrained projections of water availability measured by precipitation minus evaporation(P–E)are 0.10,0.09,and 0.22 mm d^(−1)(5.7%,4.9%,and 13.2%),respectively.The increase of precipitation and P–E projected by the high-ECS models,whose ECS values are higher than the upper limit of the likely range,are about 1.7 times larger than those estimated by constrained projections.Spatially,there is a larger increase in precipitation and P–E over the eastern TP,while the western part shows a relatively weak difference in precipitation and a drier trend in P–E.The wetter TP projected by the high-ECS models resulted from both an approximately 1.2–1.4 times stronger hydrological sensitivity and additional warming of 0.6℃–1.2℃ under all three scenarios during 2050–2099.This study emphasizes that selecting climate models with climate sensitivity within the likely range is crucial to reducing the uncertainty in the projection of TP precipitation and water availability changes.展开更多
The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of th...The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of the Tibetan Plateau,is a typical example.To understand the carbon and water fluxes,water use efficiency(WUE),and their responses to future climate change for the alpine meadow ecosystem in the Dangxiong area,two parameter estimation methods,the Model-independent Parameter Estimation(PEST)and the Dynamic Dimensions Search(DDS),were used to optimize the Biome-BGC model.Then,the gross primary productivity(GPP)and evapotranspiration(ET)were simulated.The results show that the DDS parameter calibration method has a better performance.The annual GPP and ET show an increasing trend,while the WUE shows a decreasing trend.Meanwhile,ET and GPP reach their peaks in July and August,respectively,and WUE shows a“dual-peak”pattern,reaching peaks in May and November.Furthermore,according to the simulation results for the next nearly 100 years,the ensemble average GPP and ET exhibit a significant increasing trend,and the growth rate under the SSP5–8.5 scenario is greater than that under the SSP2–4.5 scenario.WUE shows an increasing trend under the SSP2–4.5 scenario and a significant increasing trend under the SSP5–8.5 scenario.This study has important scientific significance for carbon and water cycle prediction and vegetation ecological protection on the Tibetan Plateau.展开更多
Electro-copolymerized film containing ruthenium complexes as electron-transfer(or redox)mediators and water-oxidation catalysts by an oxidative copolymerization method is presented.The addition of the redox mediator s...Electro-copolymerized film containing ruthenium complexes as electron-transfer(or redox)mediators and water-oxidation catalysts by an oxidative copolymerization method is presented.The addition of the redox mediator significantly improved the electrocatalytic water-oxidation activity and reduced the overpotential to 220 mV.The prepared electrode showed a water-oxidation catalytic rate constant kobs of 31.7 s^(-1)and an initial turnover frequency of 1.01 s^(-1)in 1000 s by potential electrolysis at 1.7 V applied bias vs NHE(normal hydrogen electrode).The kinetic isotope effect study suggests that the catalytic water oxidation reaction on the electrode surface occurs via a bimolecular coupling mechanism.展开更多
The Tibetan Plateau(TP)is a prevalent region for convection systems due to its unique thermodynamic forcing.This study investigated isolated deep convections(IDCs),which have a smaller spatial and temporal size than m...The Tibetan Plateau(TP)is a prevalent region for convection systems due to its unique thermodynamic forcing.This study investigated isolated deep convections(IDCs),which have a smaller spatial and temporal size than mesoscale convective systems(MCSs),over the TP in the rainy season(June-September)during 2001–2020.The authors used satellite precipitation and brightness temperature observations from the Global Precipitation Measurement mission.Results show that IDCs mainly concentrate over the southern TP.The IDC number per rainy season decreases from around 140 over the southern TP to around 10 over the northern TP,with an average 54.2.The initiation time of IDCs exhibits an obvious diurnal cycle,with the peak at 1400–1500 LST and the valley at 0900–1000 LST.Most IDCs last less than five hours and more than half appear for only one hour.IDCs generally have a cold cloud area of 7422.9 km^(2),containing a precipitation area of approximately 65%.The larger the IDC,the larger the fraction of intense precipitation it contains.IDCs contribute approximately 20%–30%to total precipitation and approximately 30%–40%to extreme precipitation over the TP,with a larger percentage in July and August than in June and September.In terms of spatial distribution,IDCs contribute more to both total precipitation and extreme precipitation over the TP compared to the surrounding plain regions.IDCs over the TP account for a larger fraction than MCSs,indicating the important role of IDCs over the region.展开更多
Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning p...Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning proliferation of abandoned mines posing a persistent issue.Addressing the challenges and opportunities presented by these abandoned mines,this paper advocates for a scientific approach centered on the advancement of pumped storage energy alongside gas-oil complementary energy.Leveraging abandoned mine tunnels to establish pumped storage power stations holds significant ecological and economic importance for repurposing these sites.This initiative not only serves as an effective means to restore the ecological balance in mining regions but also provides an environmentally friendly approach to repurposing abandoned mine tunnels,offering a blueprint for economically viable pumped storage power stations.This article delineates five crucial scientific considerations and outlines seven primary models for the utilization of abandoned mine sites,delineating a novel,comprehensive pathway for energy and power development that emphasizes multi-energy complementarity and synergistic optimization within abandoned mines.展开更多
[Background]As one of the most serious environmental issues in the world,soil erosion causes water pollution,reservoir siltation,soil productivity decline,thus threatens agricultural systems and even affects global cl...[Background]As one of the most serious environmental issues in the world,soil erosion causes water pollution,reservoir siltation,soil productivity decline,thus threatens agricultural systems and even affects global climate.The benefits of ecological soil and water conservation measures(ESWCMs,such as micro basins tillage and contour tillage)are widely understood,including runoff and soil loss reducing to a certain extent when compared with traditional tillage.While few studies have focused on China’s different soil types and erosion characteristics.[Methods]We reviewed literature from Web of Science,Scopus,and China National Knowledge Infrastructure using terms like“Conservation practice”“Contour tillage”“Runoff”“Sediment”“Erosion”and“China”and retained literatures based on criteria such as natural or simulated precipitation,runoff or soil loss data,reported replications and statistics,recorded factors like location and slope,and at least two data pairs per group.Ultimately,49 literatures were selected to quantify the impacts on different ESWCMs and identify the slope and precipitation for the greatest runoff and sediment reduction by calculating the log response ratio(LRR).[Results]The three regions’soil and water conservation benefits varied due to the differences in climate,terrain,and soil properties:1)ESWCMs applied in the black soil region of Northeast China were the most effective in reducing runoff and soil loss(66.65%runoff and 75.83%sediment),followed by those applied in the purple soil region of Southwest China(39.98%runoff and 58.30%sediment)and loess soil region of Northwest China(16.36%runoff and 32.44%sediment).2)Micro basins tillage(MBT)(71.79%runoff and 87.03%sediment)no-tillage with mulch(NTM)(17.30%runoff and 32.51%sediment),collecting soil to form a ridge with no-till(CSNT)(55.78%runoff and 71.36%sediment reduction)were the most efficient soil and water conservation measures in controlling water erosion in the black soil of Northeast China,the loess soil region of Northwest China and the purple soil region of Southwest China,respectively.3)The slope gradients ranged from 0-3°,>3°-5°and>10°-15°(0-3°:97.09%;>3°-5°:74.62%;and>10°-15°:39.41%)caused the largest reduction of runoff in the black soil region of Northeast China,the loess soil region of Northwest China,and the purple soil region of Southwest China.Meanwhile,the effects of sediment reduction were the most obvious,ranging from 0-3°,>10°-15°,and>20°-25°(0-3°:89.32%;>10°-15°:75.94%;and>20°-25°:67.25%).4)The effect of ESWCMs under rainstorms was the most obvious in the black soil region of Northeast China.The effect on runoff reduction under light rain in the purple soil region of Southwest China was the most obvious,but it failed to pass the significance test in sediment reduction.[Conclusions]The results provided optimal conservation tillage measures for three regions,different slopes and different rainfalls,and provided data support for reducing regional soil and water loss in China.展开更多
The effects of Ti-and Mg-bearing minerals on the crystal structure,morphology,particle size distribution,and formation mechanism of efficient desilication product of hydroandradite(HA)during hydrothermal conversion in...The effects of Ti-and Mg-bearing minerals on the crystal structure,morphology,particle size distribution,and formation mechanism of efficient desilication product of hydroandradite(HA)during hydrothermal conversion in a synthetic sodium aluminate solution were investigated via X-ray diffractometer,scanning electron microscope and particle size analyzer.During HA formation,anatase,rutile,and periclase dissolved in sodium aluminate solution engage in ion substitution reactions between Ti4+and Si4+,and between Mg^(2+)and Ca^(2+),respectively.However,dissolved hydromagnesite cannot enter into the HA.The content of HA after the hydrothermal reactions changes slightly with the increase of anatase and periclase contents,but it notably decreases with increased quantities of rutile and hydromagnesite.Ti-bearing minerals reduce the particle size and enhance the specific surface area of HA,whereas Mg-bearing minerals exert the opposite effect.The morphology of HA with Ti-and Mg-bearing minerals changes from spherical particles to flocculent structure and hexagonal plate-like particles.展开更多
In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confine...In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confined water on the limit support pressure of the tunnel face.This study employed the finite element method(FEM)to analyze the limit support pressure of shield tunnel face instability within a pressurized water-containing layer.Subsequently,a multiple linear regression approach was applied to derive a concise solution formula for the limit support pressure,incorporating various influencing factors.The analysis yields the following conclusions:1)The influence of confined water on the instability mode of the tunnel face in soft soil layers makes the displacement response of the strata not significant when the face is unstable;2)The limit support pressure increases approximately linearly with the pressure head,shield tunnel diameter,and tunnel burial depth.And inversely proportional to the thickness of the impermeable layer,soil cohesion and internal friction angle;3)Through an engineering case study analysis,the results align well with those obtained from traditional theoretical methods,thereby validating the rationality of the equations proposed in this paper.Furthermore,the proposed equations overcome the limitation of traditional theoretical approaches considering the influence of changes in impermeable layer thickness.It can accurately depict the dynamic variation in the required limit support pressure to maintain the stability of the tunnel face during shield tunneling,thus better reflecting engineering reality.展开更多
[Background]The previous studies suggest that radioactive elements like Cs and Sr may adversely affect marine ecosystems and the fishing industry.Traditional treatment systems for radioactive wastewater like the Advan...[Background]The previous studies suggest that radioactive elements like Cs and Sr may adversely affect marine ecosystems and the fishing industry.Traditional treatment systems for radioactive wastewater like the Advanced Liquid Processing System(ALPS)and Kurion have faced challenges in limiting concentration and achieving safety criteria.Studies suggest potential long-term impacts on benthic organisms and seafood networks due to radioactive elements like Cs and Sr from the discharged radioactive wastewater,which may hinder post-disaster recovery and provoke economic losses in the fishing industry both domestically and internationally.A series of studies indicate that there are issues of Cs and Sr pollution migration in soil and water conservation in Fukushima.[Methods]To provide feasible solutions,the main article includes five nuclear wastewater treatment technologies,and soil and water conservation measures for different media(water and soil)were evaluated through reviewing the previous fifteen years'articles.To provide feasible solutions,the main articles,the phytoextraction technologies in Cs and Sr treatment within different land use areas were wildly analyzed(Camellia japonica,Arabidopsis halleri and other local species).[Results]1)A 99.9%removal rate for Cs^(+)and 99.5%for Sr^(2+)was achieved by the KFe[Fe(CN)_(6)]and BaSO_(4)co-precipitation method.2)For membrane filtration,Sr^(2+)and Cs^(+)were removed using metal-organic framework(MOF/graphene oxide)and ion exchange techniques using inorganic materials like titanosilicates.The absorption efficiency of membrane filtration for Sr^(2+)and Cs^(+)was at least 92%and 94%,respectively.The study analyzed soil and water conservation technologies in different land uses,river basins and catchments.3)The underground water treatment mainly were completed via the membrance technologies like reverse osmosis and Permeable Reactive Barriers(PRB)technologies.The ^(90) Sr concentration decreased 77%-91%compared to the initial concentration by PRB technology.These diverse methods offered effective strategies for radioactive wastewater treatment,especially the co-precipitation method may be feasible remediation measures to ensure ecological safety surrounding nuclear power utilizing areas.Soil and water conservation measures for soil pollution treatment mainly focused on the use of stabilizers to hinder the migration of Cs and Sr in the soil and the effects of wind erosion such as interpolyelectrolyte complexes.[Conclusions]We evaluated the pollution of Cs and Sr in the Fukushima nuclear radiation soil and water to provide solutions for the treatment of nuclear wastewater and to prevent radionuclide pollutants from migrating into the soil and water.展开更多
Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this wo...Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program[grant number 2019QZKK0102]the Chinese Academy of Sciences[grant number 060GJHZ2023079GC].
文摘Precipitation projections over the Tibetan Plateau(TP)show diversity among existing studies,partly due to model uncertainty.How to develop a reliable projection remains inconclusive.Here,based on the IPCC AR6–assessed likely range of equilibrium climate sensitivity(ECS)and the climatological precipitation performance,the authors constrain the CMIP6(phase 6 of the Coupled Model Intercomparison Project)model projection of summer precipitation and water availability over the TP.The best estimates of precipitation changes are 0.24,0.25,and 0.45 mm d^(−1)(5.9%,6.1%,and 11.2%)under the Shared Socioeconomic Pathway(SSP)scenarios of SSP1–2.6,SSP2–4.5,and SSP5–8.5 from 2050–2099 relative to 1965–2014,respectively.The corresponding constrained projections of water availability measured by precipitation minus evaporation(P–E)are 0.10,0.09,and 0.22 mm d^(−1)(5.7%,4.9%,and 13.2%),respectively.The increase of precipitation and P–E projected by the high-ECS models,whose ECS values are higher than the upper limit of the likely range,are about 1.7 times larger than those estimated by constrained projections.Spatially,there is a larger increase in precipitation and P–E over the eastern TP,while the western part shows a relatively weak difference in precipitation and a drier trend in P–E.The wetter TP projected by the high-ECS models resulted from both an approximately 1.2–1.4 times stronger hydrological sensitivity and additional warming of 0.6℃–1.2℃ under all three scenarios during 2050–2099.This study emphasizes that selecting climate models with climate sensitivity within the likely range is crucial to reducing the uncertainty in the projection of TP precipitation and water availability changes.
基金supported by the Second Comprehensive Scientific Research Survey on the Tibetan Plateau[grant number 2019QZKK0103]the National Natural Science Foundation of China[grant numbers 42375071 and 42230610].
文摘The alpine meadow ecosystem accounts for 27%of the total area of the Tibetan Plateau and is also one of the most important vegetation types.The Dangxiong alpine meadow ecosystem,located in the south-central part of the Tibetan Plateau,is a typical example.To understand the carbon and water fluxes,water use efficiency(WUE),and their responses to future climate change for the alpine meadow ecosystem in the Dangxiong area,two parameter estimation methods,the Model-independent Parameter Estimation(PEST)and the Dynamic Dimensions Search(DDS),were used to optimize the Biome-BGC model.Then,the gross primary productivity(GPP)and evapotranspiration(ET)were simulated.The results show that the DDS parameter calibration method has a better performance.The annual GPP and ET show an increasing trend,while the WUE shows a decreasing trend.Meanwhile,ET and GPP reach their peaks in July and August,respectively,and WUE shows a“dual-peak”pattern,reaching peaks in May and November.Furthermore,according to the simulation results for the next nearly 100 years,the ensemble average GPP and ET exhibit a significant increasing trend,and the growth rate under the SSP5–8.5 scenario is greater than that under the SSP2–4.5 scenario.WUE shows an increasing trend under the SSP2–4.5 scenario and a significant increasing trend under the SSP5–8.5 scenario.This study has important scientific significance for carbon and water cycle prediction and vegetation ecological protection on the Tibetan Plateau.
文摘Electro-copolymerized film containing ruthenium complexes as electron-transfer(or redox)mediators and water-oxidation catalysts by an oxidative copolymerization method is presented.The addition of the redox mediator significantly improved the electrocatalytic water-oxidation activity and reduced the overpotential to 220 mV.The prepared electrode showed a water-oxidation catalytic rate constant kobs of 31.7 s^(-1)and an initial turnover frequency of 1.01 s^(-1)in 1000 s by potential electrolysis at 1.7 V applied bias vs NHE(normal hydrogen electrode).The kinetic isotope effect study suggests that the catalytic water oxidation reaction on the electrode surface occurs via a bimolecular coupling mechanism.
基金supported by the National Natural Science Foundation of China[grant number 42105064]the Second Tibetan Plateau Scientific Expedition and Research(STEP)program[grant number 2019QZKK0102]the special fund of the Yunnan University“double first-class”construction.
文摘The Tibetan Plateau(TP)is a prevalent region for convection systems due to its unique thermodynamic forcing.This study investigated isolated deep convections(IDCs),which have a smaller spatial and temporal size than mesoscale convective systems(MCSs),over the TP in the rainy season(June-September)during 2001–2020.The authors used satellite precipitation and brightness temperature observations from the Global Precipitation Measurement mission.Results show that IDCs mainly concentrate over the southern TP.The IDC number per rainy season decreases from around 140 over the southern TP to around 10 over the northern TP,with an average 54.2.The initiation time of IDCs exhibits an obvious diurnal cycle,with the peak at 1400–1500 LST and the valley at 0900–1000 LST.Most IDCs last less than five hours and more than half appear for only one hour.IDCs generally have a cold cloud area of 7422.9 km^(2),containing a precipitation area of approximately 65%.The larger the IDC,the larger the fraction of intense precipitation it contains.IDCs contribute approximately 20%–30%to total precipitation and approximately 30%–40%to extreme precipitation over the TP,with a larger percentage in July and August than in June and September.In terms of spatial distribution,IDCs contribute more to both total precipitation and extreme precipitation over the TP compared to the surrounding plain regions.IDCs over the TP account for a larger fraction than MCSs,indicating the important role of IDCs over the region.
基金Project(202208340045)supported by the China Scholarship Council FundProject(U21A20110)supported by the Regional Innovation and Development Joint Fund of National Natural Science Foundation of China+1 种基金Project(EUCMR202201)supported by the Open Project Program of Anhui Engineering Research Center of Exploitation and Utilization of Closed/abandoned Mine Resources,ChinaProject(2023cxcyzx063)supported by the Anhui Province New Era Talent Education Project,China。
文摘Within the framework of achieving carbon neutrality,various industries are confronted with fresh challenges.The ongoing process of downsizing coal industry operations has evolved into a new phase,with the burgeoning proliferation of abandoned mines posing a persistent issue.Addressing the challenges and opportunities presented by these abandoned mines,this paper advocates for a scientific approach centered on the advancement of pumped storage energy alongside gas-oil complementary energy.Leveraging abandoned mine tunnels to establish pumped storage power stations holds significant ecological and economic importance for repurposing these sites.This initiative not only serves as an effective means to restore the ecological balance in mining regions but also provides an environmentally friendly approach to repurposing abandoned mine tunnels,offering a blueprint for economically viable pumped storage power stations.This article delineates five crucial scientific considerations and outlines seven primary models for the utilization of abandoned mine sites,delineating a novel,comprehensive pathway for energy and power development that emphasizes multi-energy complementarity and synergistic optimization within abandoned mines.
基金Science and Technology Major Project of Tibetan Autonomous Region of China(XZ202201ZD0005G02)National Natural Science Foundation of China(42277353)Chengdu Science and Technology Project(2022-YF05-01162-SN)。
文摘[Background]As one of the most serious environmental issues in the world,soil erosion causes water pollution,reservoir siltation,soil productivity decline,thus threatens agricultural systems and even affects global climate.The benefits of ecological soil and water conservation measures(ESWCMs,such as micro basins tillage and contour tillage)are widely understood,including runoff and soil loss reducing to a certain extent when compared with traditional tillage.While few studies have focused on China’s different soil types and erosion characteristics.[Methods]We reviewed literature from Web of Science,Scopus,and China National Knowledge Infrastructure using terms like“Conservation practice”“Contour tillage”“Runoff”“Sediment”“Erosion”and“China”and retained literatures based on criteria such as natural or simulated precipitation,runoff or soil loss data,reported replications and statistics,recorded factors like location and slope,and at least two data pairs per group.Ultimately,49 literatures were selected to quantify the impacts on different ESWCMs and identify the slope and precipitation for the greatest runoff and sediment reduction by calculating the log response ratio(LRR).[Results]The three regions’soil and water conservation benefits varied due to the differences in climate,terrain,and soil properties:1)ESWCMs applied in the black soil region of Northeast China were the most effective in reducing runoff and soil loss(66.65%runoff and 75.83%sediment),followed by those applied in the purple soil region of Southwest China(39.98%runoff and 58.30%sediment)and loess soil region of Northwest China(16.36%runoff and 32.44%sediment).2)Micro basins tillage(MBT)(71.79%runoff and 87.03%sediment)no-tillage with mulch(NTM)(17.30%runoff and 32.51%sediment),collecting soil to form a ridge with no-till(CSNT)(55.78%runoff and 71.36%sediment reduction)were the most efficient soil and water conservation measures in controlling water erosion in the black soil of Northeast China,the loess soil region of Northwest China and the purple soil region of Southwest China,respectively.3)The slope gradients ranged from 0-3°,>3°-5°and>10°-15°(0-3°:97.09%;>3°-5°:74.62%;and>10°-15°:39.41%)caused the largest reduction of runoff in the black soil region of Northeast China,the loess soil region of Northwest China,and the purple soil region of Southwest China.Meanwhile,the effects of sediment reduction were the most obvious,ranging from 0-3°,>10°-15°,and>20°-25°(0-3°:89.32%;>10°-15°:75.94%;and>20°-25°:67.25%).4)The effect of ESWCMs under rainstorms was the most obvious in the black soil region of Northeast China.The effect on runoff reduction under light rain in the purple soil region of Southwest China was the most obvious,but it failed to pass the significance test in sediment reduction.[Conclusions]The results provided optimal conservation tillage measures for three regions,different slopes and different rainfalls,and provided data support for reducing regional soil and water loss in China.
基金financial supports from the National Key R&D Program of China (No.2022YFC2904401)the National Natural Science Foundation of China (Nos.22078055,51774079)the Fundamental Research Funds for the Central Universities,China (No.N2225002)。
文摘The effects of Ti-and Mg-bearing minerals on the crystal structure,morphology,particle size distribution,and formation mechanism of efficient desilication product of hydroandradite(HA)during hydrothermal conversion in a synthetic sodium aluminate solution were investigated via X-ray diffractometer,scanning electron microscope and particle size analyzer.During HA formation,anatase,rutile,and periclase dissolved in sodium aluminate solution engage in ion substitution reactions between Ti4+and Si4+,and between Mg^(2+)and Ca^(2+),respectively.However,dissolved hydromagnesite cannot enter into the HA.The content of HA after the hydrothermal reactions changes slightly with the increase of anatase and periclase contents,but it notably decreases with increased quantities of rutile and hydromagnesite.Ti-bearing minerals reduce the particle size and enhance the specific surface area of HA,whereas Mg-bearing minerals exert the opposite effect.The morphology of HA with Ti-and Mg-bearing minerals changes from spherical particles to flocculent structure and hexagonal plate-like particles.
基金Project(ZDRW-ZS-2021-3)supported by the Key Deployment Projects of Chinese Academy of SciencesProjects(52179116,51991392)supported by the National Natural Science Foundation of China。
文摘In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confined water on the limit support pressure of the tunnel face.This study employed the finite element method(FEM)to analyze the limit support pressure of shield tunnel face instability within a pressurized water-containing layer.Subsequently,a multiple linear regression approach was applied to derive a concise solution formula for the limit support pressure,incorporating various influencing factors.The analysis yields the following conclusions:1)The influence of confined water on the instability mode of the tunnel face in soft soil layers makes the displacement response of the strata not significant when the face is unstable;2)The limit support pressure increases approximately linearly with the pressure head,shield tunnel diameter,and tunnel burial depth.And inversely proportional to the thickness of the impermeable layer,soil cohesion and internal friction angle;3)Through an engineering case study analysis,the results align well with those obtained from traditional theoretical methods,thereby validating the rationality of the equations proposed in this paper.Furthermore,the proposed equations overcome the limitation of traditional theoretical approaches considering the influence of changes in impermeable layer thickness.It can accurately depict the dynamic variation in the required limit support pressure to maintain the stability of the tunnel face during shield tunneling,thus better reflecting engineering reality.
基金Xiong′an New Area Science and Technology Innovation Project(2022XACX1000)。
文摘[Background]The previous studies suggest that radioactive elements like Cs and Sr may adversely affect marine ecosystems and the fishing industry.Traditional treatment systems for radioactive wastewater like the Advanced Liquid Processing System(ALPS)and Kurion have faced challenges in limiting concentration and achieving safety criteria.Studies suggest potential long-term impacts on benthic organisms and seafood networks due to radioactive elements like Cs and Sr from the discharged radioactive wastewater,which may hinder post-disaster recovery and provoke economic losses in the fishing industry both domestically and internationally.A series of studies indicate that there are issues of Cs and Sr pollution migration in soil and water conservation in Fukushima.[Methods]To provide feasible solutions,the main article includes five nuclear wastewater treatment technologies,and soil and water conservation measures for different media(water and soil)were evaluated through reviewing the previous fifteen years'articles.To provide feasible solutions,the main articles,the phytoextraction technologies in Cs and Sr treatment within different land use areas were wildly analyzed(Camellia japonica,Arabidopsis halleri and other local species).[Results]1)A 99.9%removal rate for Cs^(+)and 99.5%for Sr^(2+)was achieved by the KFe[Fe(CN)_(6)]and BaSO_(4)co-precipitation method.2)For membrane filtration,Sr^(2+)and Cs^(+)were removed using metal-organic framework(MOF/graphene oxide)and ion exchange techniques using inorganic materials like titanosilicates.The absorption efficiency of membrane filtration for Sr^(2+)and Cs^(+)was at least 92%and 94%,respectively.The study analyzed soil and water conservation technologies in different land uses,river basins and catchments.3)The underground water treatment mainly were completed via the membrance technologies like reverse osmosis and Permeable Reactive Barriers(PRB)technologies.The ^(90) Sr concentration decreased 77%-91%compared to the initial concentration by PRB technology.These diverse methods offered effective strategies for radioactive wastewater treatment,especially the co-precipitation method may be feasible remediation measures to ensure ecological safety surrounding nuclear power utilizing areas.Soil and water conservation measures for soil pollution treatment mainly focused on the use of stabilizers to hinder the migration of Cs and Sr in the soil and the effects of wind erosion such as interpolyelectrolyte complexes.[Conclusions]We evaluated the pollution of Cs and Sr in the Fukushima nuclear radiation soil and water to provide solutions for the treatment of nuclear wastewater and to prevent radionuclide pollutants from migrating into the soil and water.
基金Project(8212033)supported by the Natural Science Foundation of Beijing,ChinaProject(BBJ2023051)supported by the Fundamental Research Funds of China University of Mining and Technology-BeijingProject(SKLGDUEK202221)supported by the Innovation Fund Research Project,China。
文摘Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated.
