Soil moisture is an important resource for plant growth on the arid and semi-arid Loess Plateau of China where the‘‘Grain for Green’’project was launched in 1999,but there has been no systematic evaluation of soil...Soil moisture is an important resource for plant growth on the arid and semi-arid Loess Plateau of China where the‘‘Grain for Green’’project was launched in 1999,but there has been no systematic evaluation of soil moisture from the effects of ecological restoration at a regional scale.We systematically assessed 63 published studies during 2000-2015,including 2050 observations at 68 sites on the Loess Plateau with the aim of determining soil moisture changes and the factors influencing those changes.We found that,after land use conversion,soil moisture decreased by 17%in the upper 100 cm soil layer and that tree plantations and shrub lands appeared to cause soil moisture depletion which became increasingly serious with soil depth.The decrease of soil moisture was significantly influenced by the planting species in all restoration types(tree plantations,shrub lands,and grasslands).We also found that tree plantations and grasslands converted from farmlands consumed more soil moisture than from wasteland(including bare land,abandoned land and wild grasslands).Artificial restoration led to significant soil moisture reduction,but natural restoration had little effect on soil moisture.Therefore,natural restoration should be an alternative restoration practice on the Loess Plateau.These results will provide helpful information for artificial afforestation and planning ecological restoration campaigns for policy makers on water-limited regions.展开更多
During carbon capture from steel slag,large amounts of calcium and magnesium are utilized,whereas silica is largely unutilized.In this study,porous SiO_(2) materials were synthesized from the silicon in steel slag for...During carbon capture from steel slag,large amounts of calcium and magnesium are utilized,whereas silica is largely unutilized.In this study,porous SiO_(2) materials were synthesized from the silicon in steel slag for use in indirect carbon capturing.The porous SiO_(2) materials were synthesized from γ-dicalcium silicate(γ-Ca_(2)SiO_(4) or γ-C_(2)S),the main silicon-containing phase in steel slag.The phase exhibits moderate reactivity,and the synthesis of the materials was achieved by optimizing the synthesis parameters and minimizing the influence of other elements present in the slag.The effects of synthesis temperature and pH value of the porous SiO_(2) materials on their morphologies,structural parameters,and CO_(2) sorption performance were investigated.Using cetyltrimethylammonium bromide as a template agent,porous SiO_(2) materials with controllable structural properties could be prepared by adjusting their synthesis temperature and pH values.Porous SiO_(2) materials with outstanding properties,such as tunable pore diameters and high specific surfaces(~1000 m^(2)/g) were synthesized in an acidic solution via different types of interactions between the organic template and inorganic silica species.The maximum CO_(2) sorption capacity of the porous SiO_(2) material samples exceeded 70 mg/g.A resource u tilization mechanism for transforming silica sources in steel slag into porous SiO_(2) materials is proposed in the study.Highly ordered,pure porous SiO_(2) materials with large specific surface areas were successfully synthesized from steel slag.The results indicated that steel-slag-based porous SiO_(2) materials would be promising candidates for the in situ CO_(2) capture in the steel industry.展开更多
文摘Soil moisture is an important resource for plant growth on the arid and semi-arid Loess Plateau of China where the‘‘Grain for Green’’project was launched in 1999,but there has been no systematic evaluation of soil moisture from the effects of ecological restoration at a regional scale.We systematically assessed 63 published studies during 2000-2015,including 2050 observations at 68 sites on the Loess Plateau with the aim of determining soil moisture changes and the factors influencing those changes.We found that,after land use conversion,soil moisture decreased by 17%in the upper 100 cm soil layer and that tree plantations and shrub lands appeared to cause soil moisture depletion which became increasingly serious with soil depth.The decrease of soil moisture was significantly influenced by the planting species in all restoration types(tree plantations,shrub lands,and grasslands).We also found that tree plantations and grasslands converted from farmlands consumed more soil moisture than from wasteland(including bare land,abandoned land and wild grasslands).Artificial restoration led to significant soil moisture reduction,but natural restoration had little effect on soil moisture.Therefore,natural restoration should be an alternative restoration practice on the Loess Plateau.These results will provide helpful information for artificial afforestation and planning ecological restoration campaigns for policy makers on water-limited regions.
基金support from the National Natural Science Foundation of China (No. 52374327)the Liaoning Province “Xingliao Talent Program” Project (No. XLYC2403148)+1 种基金the Key project of Liaoning Provincial Department of Education in 2024 (No. LJ212411430036)the Doctoral Research Initiation Fund Project of Liaoning Institute of Science and Technology (No. 2407B12)。
文摘During carbon capture from steel slag,large amounts of calcium and magnesium are utilized,whereas silica is largely unutilized.In this study,porous SiO_(2) materials were synthesized from the silicon in steel slag for use in indirect carbon capturing.The porous SiO_(2) materials were synthesized from γ-dicalcium silicate(γ-Ca_(2)SiO_(4) or γ-C_(2)S),the main silicon-containing phase in steel slag.The phase exhibits moderate reactivity,and the synthesis of the materials was achieved by optimizing the synthesis parameters and minimizing the influence of other elements present in the slag.The effects of synthesis temperature and pH value of the porous SiO_(2) materials on their morphologies,structural parameters,and CO_(2) sorption performance were investigated.Using cetyltrimethylammonium bromide as a template agent,porous SiO_(2) materials with controllable structural properties could be prepared by adjusting their synthesis temperature and pH values.Porous SiO_(2) materials with outstanding properties,such as tunable pore diameters and high specific surfaces(~1000 m^(2)/g) were synthesized in an acidic solution via different types of interactions between the organic template and inorganic silica species.The maximum CO_(2) sorption capacity of the porous SiO_(2) material samples exceeded 70 mg/g.A resource u tilization mechanism for transforming silica sources in steel slag into porous SiO_(2) materials is proposed in the study.Highly ordered,pure porous SiO_(2) materials with large specific surface areas were successfully synthesized from steel slag.The results indicated that steel-slag-based porous SiO_(2) materials would be promising candidates for the in situ CO_(2) capture in the steel industry.
