Geothermal energy has gained wide attention as a renewable alternative for mitigating greenhouse gas emissions.The advancements in enhanced geothermal system technology have enabled the exploitation of previously inac...Geothermal energy has gained wide attention as a renewable alternative for mitigating greenhouse gas emissions.The advancements in enhanced geothermal system technology have enabled the exploitation of previously inaccessible geothermal resources.However,the extraction of geothermal energy from deep reservoirs poses many challenges due to high‐temperature and high‐geostress conditions.These factors can significantly impact the surrounding rock and its fracture formation.A comprehensive understanding of the thermal–hydraulic–mechanical(THM)coupling effect is crucial to the safe and efficient exploitation of geothermal resources.This study presented a THM coupling numerical model for the geothermal reservoir of the Yangbajing geothermal system.This proposed model investigated the geothermal exploitation performance and the stress distribution within the reservoir under various combinations of geothermal wells and mass flow rates.The geothermal system performance was evaluated by the criteria of outlet temperature and geothermal productivity.The results indicate that the longer distance between wells can increase the outlet temperature of production wells and improve extraction efficiency in the short term.In contrast,the shorter distance between wells can reduce the heat exchange area and thus mitigate the impact on the reservoir stress.A larger mass flow rate is conducive to the production capacity enhancement of the geothermal system and,in turn causes a wider range of stress disturbance.These findings provide valuable insights into the optimization of geothermal energy extraction while considering reservoir safety and long‐term sustainability.This study deepens the understanding of the THM coupling effects in geothermal systems and provides an efficient and environmentally friendly strategy for a geothermal energy system.展开更多
Nanoscale powder of SiO2/Al2O3/TiO2 composite was prepared by sol-gel method. Microstructure and morphology of the obtained samples were characterized by infrared （IR）, X-ray diffraction （XRD） analysis and transmi...Nanoscale powder of SiO2/Al2O3/TiO2 composite was prepared by sol-gel method. Microstructure and morphology of the obtained samples were characterized by infrared （IR）, X-ray diffraction （XRD） analysis and transmission electron microscopy （TEM）. It is proved that infrared absorbing peaks of the samples are in waveband range of 1300-400 cm^-1, and the peak shape changes with their component. Mechanism of the infrared peak＇s positions and shapes which changes with the size and morphology of the prepared nano-particles has been tentatively discussed.展开更多
The films of Ge and Si were grown on the substrate Si (100) by magnetron sputtering at 2.5 Pa Ar pressure.The growth temperature of films was 100℃,250℃,400℃and 550℃.The structure and composition were analysised by...The films of Ge and Si were grown on the substrate Si (100) by magnetron sputtering at 2.5 Pa Ar pressure.The growth temperature of films was 100℃,250℃,400℃and 550℃.The structure and composition were analysised by Raman scattering.The poly-crystal peak and crystal peak of Ge were observed in these films.The results indicate that the single crystal film of Ge was prepared at the substrate temperature of 400℃.The peak of acoustic phonons of Ge was 98 cm^(-1) and that of Si was 170 cm^(-1).展开更多
Organic room-temperature phosphorescence(RTP)materials have been used in high-resolution imaging.However,the development of long-wavelength-emis sion RTP materials in aqueous solution remains a challenge.Here,we repor...Organic room-temperature phosphorescence(RTP)materials have been used in high-resolution imaging.However,the development of long-wavelength-emis sion RTP materials in aqueous solution remains a challenge.Here,we report red-emissive RTP materials via integration of the ring-fusing effect and host–vip interaction.展开更多
基金supported by the financial support from the National Natural Science Foundation of China(52204084)Project funded by the China Postdoctoral Science Foundation(2021M700388).
文摘Geothermal energy has gained wide attention as a renewable alternative for mitigating greenhouse gas emissions.The advancements in enhanced geothermal system technology have enabled the exploitation of previously inaccessible geothermal resources.However,the extraction of geothermal energy from deep reservoirs poses many challenges due to high‐temperature and high‐geostress conditions.These factors can significantly impact the surrounding rock and its fracture formation.A comprehensive understanding of the thermal–hydraulic–mechanical(THM)coupling effect is crucial to the safe and efficient exploitation of geothermal resources.This study presented a THM coupling numerical model for the geothermal reservoir of the Yangbajing geothermal system.This proposed model investigated the geothermal exploitation performance and the stress distribution within the reservoir under various combinations of geothermal wells and mass flow rates.The geothermal system performance was evaluated by the criteria of outlet temperature and geothermal productivity.The results indicate that the longer distance between wells can increase the outlet temperature of production wells and improve extraction efficiency in the short term.In contrast,the shorter distance between wells can reduce the heat exchange area and thus mitigate the impact on the reservoir stress.A larger mass flow rate is conducive to the production capacity enhancement of the geothermal system and,in turn causes a wider range of stress disturbance.These findings provide valuable insights into the optimization of geothermal energy extraction while considering reservoir safety and long‐term sustainability.This study deepens the understanding of the THM coupling effects in geothermal systems and provides an efficient and environmentally friendly strategy for a geothermal energy system.
基金the Science Foundation of Yunnan Province under grant No.2001E0003Z.
文摘Nanoscale powder of SiO2/Al2O3/TiO2 composite was prepared by sol-gel method. Microstructure and morphology of the obtained samples were characterized by infrared （IR）, X-ray diffraction （XRD） analysis and transmission electron microscopy （TEM）. It is proved that infrared absorbing peaks of the samples are in waveband range of 1300-400 cm^-1, and the peak shape changes with their component. Mechanism of the infrared peak＇s positions and shapes which changes with the size and morphology of the prepared nano-particles has been tentatively discussed.
基金supported by the National Natural Science Foundation of China(No.60272001)the Beijing Natural Science Foundation of China(No.4032010)the Yunnan Natural Province Science Foundation of China(Youth Foundation:No.K1010265)
文摘The films of Ge and Si were grown on the substrate Si (100) by magnetron sputtering at 2.5 Pa Ar pressure.The growth temperature of films was 100℃,250℃,400℃and 550℃.The structure and composition were analysised by Raman scattering.The poly-crystal peak and crystal peak of Ge were observed in these films.The results indicate that the single crystal film of Ge was prepared at the substrate temperature of 400℃.The peak of acoustic phonons of Ge was 98 cm^(-1) and that of Si was 170 cm^(-1).
基金supported by the National Natural Scientific Foundation of China(grant nos.21975021,51803009,21905021,51673024,21975020,and 21875019)supported by Beijing National Laboratory for Molecular Sciences(no.BNLMS202007),China Postdoctoral Science Foundation 2019TQ0034.
文摘Organic room-temperature phosphorescence(RTP)materials have been used in high-resolution imaging.However,the development of long-wavelength-emis sion RTP materials in aqueous solution remains a challenge.Here,we report red-emissive RTP materials via integration of the ring-fusing effect and host–vip interaction.
