The issue of top contact in paste backfill materials is a common technical challenge in coal mine filling processes,and overcoming this problem has become a significant research direction in current studies and engine...The issue of top contact in paste backfill materials is a common technical challenge in coal mine filling processes,and overcoming this problem has become a significant research direction in current studies and engineering practices.This paper utilizes coal gangue as aggregate and hydrogen peroxide as a foaming agent to prepare foamed paste backfill materials.Three close-packing theories were employed to investigate the effects of different coal gangue particle gradations on the mechanical properties,expansion ratio,water absorption,and dry density of foamed paste backfill materials under the same foaming agent content.The hydration mechanism and pore structure evolution were analyzed using XRD,SEM,and OSM techniques.The results indicate that when the hydrogen peroxide addition is 5%,the foamed paste backfill material regulated by MAA gradation theory exhibits the best comprehensive performance,achieving a 28-day compressive strength of 0.89 MPa,an expansion ratio of 155.5%,and a dry density of 1.24 g/cm^(3).The regulation of coal gangue aggregate particle gradation not only improves the foaming efficiency but also allows the formation of CH to fill the material pores,enhancing the overall structural support capacity and forming a closer microstructure.This research provides new insights into controlling the properties of foamed paste backfill materials.展开更多
The carbon market auction mechanism is an important policy tool for carbon pricing and a key mechanism that supports carbon emission neutralization,especially for China.A few systematic studies exist on China’s carbo...The carbon market auction mechanism is an important policy tool for carbon pricing and a key mechanism that supports carbon emission neutralization,especially for China.A few systematic studies exist on China’s carbon market auction mechanism.This article focuses on the five auction mechanisms in Chinese pilot emission trading schemes(ETS),reviews the structures and bidding situation of the five-pilot auction mechanism,extracts the similarities,and analyzes their different features,such as auction mode,bidding scale,participants,pricing mode,auction frequency,and so on.This study conducts an in-depth analysis of the carbon allowance auction mechanism in the Guangdong pilot ETS of China,including its development and the evolution of the key elements,its operational effects,and related disputes.Finally,this study puts forward the trend forecast and suggestions for the Chinese allowance auction mechanism,such as the time window of launching national allowance auctions,the most likely auction mode,carbon pricing,and bidding revenue management.Carbon pricing by auction is the most powerful policy tool for addressing carbon emissions reduction and implementing the Glasgow Climate Pact.展开更多
基金National Natural Science Foundation of China(Project No.:U1905216).
文摘The issue of top contact in paste backfill materials is a common technical challenge in coal mine filling processes,and overcoming this problem has become a significant research direction in current studies and engineering practices.This paper utilizes coal gangue as aggregate and hydrogen peroxide as a foaming agent to prepare foamed paste backfill materials.Three close-packing theories were employed to investigate the effects of different coal gangue particle gradations on the mechanical properties,expansion ratio,water absorption,and dry density of foamed paste backfill materials under the same foaming agent content.The hydration mechanism and pore structure evolution were analyzed using XRD,SEM,and OSM techniques.The results indicate that when the hydrogen peroxide addition is 5%,the foamed paste backfill material regulated by MAA gradation theory exhibits the best comprehensive performance,achieving a 28-day compressive strength of 0.89 MPa,an expansion ratio of 155.5%,and a dry density of 1.24 g/cm^(3).The regulation of coal gangue aggregate particle gradation not only improves the foaming efficiency but also allows the formation of CH to fill the material pores,enhancing the overall structural support capacity and forming a closer microstructure.This research provides new insights into controlling the properties of foamed paste backfill materials.
基金supported by Shenzhen Philosophy and Social Sciences Planning in 2021[Grant No.SZ2021A006]the Basic Theoretical Research in the 13th Five Year Plan of Guangdong Philosophy and Social Sciences in 2020[Grant No.GD20 YDXZGL09]and the Characteristic Innovation Projects of Guangdong Universities in China[Grant No.2021WTSCX035].
文摘The carbon market auction mechanism is an important policy tool for carbon pricing and a key mechanism that supports carbon emission neutralization,especially for China.A few systematic studies exist on China’s carbon market auction mechanism.This article focuses on the five auction mechanisms in Chinese pilot emission trading schemes(ETS),reviews the structures and bidding situation of the five-pilot auction mechanism,extracts the similarities,and analyzes their different features,such as auction mode,bidding scale,participants,pricing mode,auction frequency,and so on.This study conducts an in-depth analysis of the carbon allowance auction mechanism in the Guangdong pilot ETS of China,including its development and the evolution of the key elements,its operational effects,and related disputes.Finally,this study puts forward the trend forecast and suggestions for the Chinese allowance auction mechanism,such as the time window of launching national allowance auctions,the most likely auction mode,carbon pricing,and bidding revenue management.Carbon pricing by auction is the most powerful policy tool for addressing carbon emissions reduction and implementing the Glasgow Climate Pact.
