The coupled chemo-mechanical impact of supercritical CO_(2)-H_(2)O(ScCO_(2)-H_(2)O)reactions on fracture geometry and nonlinear flow regimes in deep shale under confining pressures remains inadequately quantified.This...The coupled chemo-mechanical impact of supercritical CO_(2)-H_(2)O(ScCO_(2)-H_(2)O)reactions on fracture geometry and nonlinear flow regimes in deep shale under confining pressures remains inadequately quantified.This study systematically investigates the effects of ScCO_(2)-H_(2)O-shale interactions on fracture morphology and flow properties under confining pressures from 15 MPa to 40 MPa by integrating XRD(X-ray diffraction),micro-CT,3D surface profilometry,and multistage steady-state flow experiments.The results demonstrate that ScCO_(2)-H_(2)O exposure drives pyrite/feldspar dissolution and localized clay precipitation,resulting in fracture branching and macroscopic aperture regularization.Critically,confining pressure dictates the net hydraulic response:under low confining pressure(15-25 MPa),dissolution dominates,enhancing permeability,flow efficiency(Q/VP),and pre-linear flow behavior(n<1).At high confining pressures(30-40 MPa)mechanical compaction and mineral precipitation amplify flow resistance,shifting the flow regime toward quasi-linear behavior,as inertial effects become negligible compared to dominant viscous forces and increased flow resistance.Confining pressure thus critically mediates the dissolution-precipitation balance during ScCO_(2)-H_(2)O treatment,with an optimal window of 15-25 MPa identified for enhancing conductivity while minimizing clogging risk.These findings provide a quantitative framework for predicting stress-dependent flow evolution in chemically altered shale fractures.展开更多
Inorganic materials can solve transportable and on-site hydrolytic hydrogen generation issues.CaH_(2)/(Al/Si)composites are preferable due to their notable chemical properties.However,these composites require pretreat...Inorganic materials can solve transportable and on-site hydrolytic hydrogen generation issues.CaH_(2)/(Al/Si)composites are preferable due to their notable chemical properties.However,these composites require pretreatments,an inert environment,and long hours of physical ball milling for high homogeneity and synergistic effects.CaH_(2)also inhibits the hydrolysis reaction by forming its products on the Al/Si surface,which hinders the direct utilization of composites.This work represents the first investigation of NaH-CaH_(2)(Al/Si)fuel composites,which greatly overcome these limitations and can be directly used for on-site hydrogen generation and proton exchange membrane(PEM)fuel cells.The NaH-CaH_(2)(Al/Si)fuel composites were prepared by using a straightforward mixing method with variable composition ratios,showing high H_(2)yield and fuel cell(FC)performance.NaH addition provides the bridge effect,which opens up a new way to enable efficient hydrolysis and greatly enhances the hydrolysis activity of CaH_(2)/(Al/Si)composites.The novel fuel composites(NaH-CaH_(2)/Al)have extraordinary FC performance and a 0.42 W/cm2 peak power density greater than commercial hydrogen generators.It provides high H_(2)yield 84.4%for NaH-CaH_(2)/Al and 82%for NaH-CaH_(2)/Si compared to NaOH-CaH_(2)(Al/Si),NaCl-CaH_(2)(Al/Si),and KCl-CaH_(2)(Al/Si)composites.The NaH bridge effect hinders the direct water contact and stops the formation of Ca(OH)2 around Al/Si,which provides adequate pathways for the CaH_(2)(Al/Si)hydrolysis.The impressive capabilities of novel fuel composites are anticipated to offer practical uses in fuel cells,automobile applications,and portable/on-board H_(2)generation.展开更多
Simultaneous integration of rich oxygen vacancies(OVs)and twin crystals in a photocatalyst can not only significantly enhance the near-infrared(NIR)light response but also greatly improve the photocharge separation an...Simultaneous integration of rich oxygen vacancies(OVs)and twin crystals in a photocatalyst can not only significantly enhance the near-infrared(NIR)light response but also greatly improve the photocharge separation and transfer efficiency owing to the induced high electrical conductivity and strong built-in electric field.However,thus far,there has been a lack of a model catalyst containing both twin crystals and OVs.Herein,we develop a simple wet chemical strategy for synthesizing of unprecedented NIR light-responsive OVs-rich Cu_(2)O black nanoparticles with high-density of twin crystals(denoted as black twinned Cu_(2)O).As expected,the black twinned Cu_(2)O exhibits higher visible-NIR and NIR light-driven photodegradation of tetracycline(TC)solution than the counterparts.Significantly,the mechanism insight into twin-dependent photocatalysis in NIR light-responsive Cu_(2)O black nanocrystals with rich OVs is uncovered in depth by density functional theory(DFT)calculations and a series of experimental evidence.Expectantly,this work would be beneficial for the scientific researchers currently focusing on the NIR light-responsive photocatalysis and twin engineering of photocatalysts.展开更多
Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces...Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces was attributed to the reducibility of 2-methoxyethanol in the precursor solution.Comparative photocatalytic evaluation reveals that the Bi/Bi_(2)Fe_(4)O_(9)nanocomposites significantly enhance the degradation efficiency(99.0%)of bisphenol A compared with Bi_(2)Fe_(4)O_(9)nanosheets(64.2%)under 120 min simulated solar irradiation.This remarkable enhancement can be attributed to the established Bi/Bi_(2)Fe_(4)O_(9)heterojunction structure,which effectively facilitates the separation of photogenerated electron-hole pairs and accelerates interfacial charge transfer between the metallic Bi nanodots and semiconductor Bi_(2)Fe_(4)O_(9)nanosheets.The synergistic effects arising from this unique architecture ultimately lead to superior photocatalytic performance.展开更多
Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making th...Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn^(2+)hinder their development.Herein,we present a highperformance thermal charging cell design using Zn^(2+)/NH_(4)^(+)hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH_(4)^(+).Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K^(-1)and an excellent normalized power density of 19.6 mW m^(-2)K^(-2)at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.展开更多
Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse...Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse gas N_(2)O emissions from acidic soil mediated by long-term manure application remain poorly understood. Herein, we investigated N_(2)O emission and its linkage with gross N mineralization and nitrification rates, as well as nitrifying and denitrifying microbes in an acidic upland soil subjected to 36-year fertilization treatments, including an unfertilized control(CK), inorganic fertilizer(F), 2× rate of inorganic fertilizer(2F), manure(M), and the combination of inorganic fertilizer and manure(FM) treatments. Compared to the CK treatment(1.34 μg N kg^(-1) d^(-1)), fertilization strongly increased N_(2)O emissions by 34-fold on average, with more pronounced increases in the manure-amendment(10.6-169 μg N kg^(-1) d^(-1)) than those in the inorganic fertilizer treatments(3.26-5.51 μg N kg^(-1) d^(-1)). The manure amendment-stimulated N_(2)O emissions were highly associated with increased soil pH, mean weight diameter of soil aggregates, substrate availability(e.g., particulate organic carbon, NO_(3)^(-)and available phosphorus), gross N mineralization rates, denitrifier abundances and the(nirK+nirS)/nosZ ratio. These findings suggest that the increased N_(2)O emissions primarily resulted from alleviated acidification, increased substrate availability and improved soil structure, thus enhancing microbial N mineralization and favoring N_(2)O^(-)producing denitrifiers over N_(2)O consumers. Moreover, ammonia-oxidizing bacteria(AOB) rather than ammonia-oxidizing archaea(AOA) positively correlated with soil NO_(3)^(-)concentration and N_(2)O emissions, indicating that nitrification indirectly contributed to N_(2)O production by supplying NO_(3)^(-)for denitrification. Collectively, manure amendment potentially stimulates N_(2)O emissions, primarily resulting from alleviated soil acidification and increased substrate availability, thus enhancing N mineralization and denitrifier-mediated N_(2)O production. Our findings suggest that consideration should be given to the greenhouse gas budgets of agricultural ecosystems when applying manure for managing the pH and fertility of acidic soils.展开更多
基金support from the Science and Technology Innovation Program of Hunan Province(Grant No.2023RC1021)the Natural Science Foundation of Sichuan Province(Grant No.2025YFHZ0323).-。
文摘The coupled chemo-mechanical impact of supercritical CO_(2)-H_(2)O(ScCO_(2)-H_(2)O)reactions on fracture geometry and nonlinear flow regimes in deep shale under confining pressures remains inadequately quantified.This study systematically investigates the effects of ScCO_(2)-H_(2)O-shale interactions on fracture morphology and flow properties under confining pressures from 15 MPa to 40 MPa by integrating XRD(X-ray diffraction),micro-CT,3D surface profilometry,and multistage steady-state flow experiments.The results demonstrate that ScCO_(2)-H_(2)O exposure drives pyrite/feldspar dissolution and localized clay precipitation,resulting in fracture branching and macroscopic aperture regularization.Critically,confining pressure dictates the net hydraulic response:under low confining pressure(15-25 MPa),dissolution dominates,enhancing permeability,flow efficiency(Q/VP),and pre-linear flow behavior(n<1).At high confining pressures(30-40 MPa)mechanical compaction and mineral precipitation amplify flow resistance,shifting the flow regime toward quasi-linear behavior,as inertial effects become negligible compared to dominant viscous forces and increased flow resistance.Confining pressure thus critically mediates the dissolution-precipitation balance during ScCO_(2)-H_(2)O treatment,with an optimal window of 15-25 MPa identified for enhancing conductivity while minimizing clogging risk.These findings provide a quantitative framework for predicting stress-dependent flow evolution in chemically altered shale fractures.
基金financial support granted by the National Natural Science Foundation of China (No. 22402225)the Gusu Innovation and Entrepreneurship Leading Talent Plan(No. ZXL2023193)+2 种基金the Sinano Talents Plan (No. 2022000175)the Guangdong Basic and Applied Basic Research Foundation (No.2023A1515111133)the ANSO Scholarship for Young Talents
文摘Inorganic materials can solve transportable and on-site hydrolytic hydrogen generation issues.CaH_(2)/(Al/Si)composites are preferable due to their notable chemical properties.However,these composites require pretreatments,an inert environment,and long hours of physical ball milling for high homogeneity and synergistic effects.CaH_(2)also inhibits the hydrolysis reaction by forming its products on the Al/Si surface,which hinders the direct utilization of composites.This work represents the first investigation of NaH-CaH_(2)(Al/Si)fuel composites,which greatly overcome these limitations and can be directly used for on-site hydrogen generation and proton exchange membrane(PEM)fuel cells.The NaH-CaH_(2)(Al/Si)fuel composites were prepared by using a straightforward mixing method with variable composition ratios,showing high H_(2)yield and fuel cell(FC)performance.NaH addition provides the bridge effect,which opens up a new way to enable efficient hydrolysis and greatly enhances the hydrolysis activity of CaH_(2)/(Al/Si)composites.The novel fuel composites(NaH-CaH_(2)/Al)have extraordinary FC performance and a 0.42 W/cm2 peak power density greater than commercial hydrogen generators.It provides high H_(2)yield 84.4%for NaH-CaH_(2)/Al and 82%for NaH-CaH_(2)/Si compared to NaOH-CaH_(2)(Al/Si),NaCl-CaH_(2)(Al/Si),and KCl-CaH_(2)(Al/Si)composites.The NaH bridge effect hinders the direct water contact and stops the formation of Ca(OH)2 around Al/Si,which provides adequate pathways for the CaH_(2)(Al/Si)hydrolysis.The impressive capabilities of novel fuel composites are anticipated to offer practical uses in fuel cells,automobile applications,and portable/on-board H_(2)generation.
基金supported by the National Natural Science Foundation of China(NSFC Nos.52271228,52127802,52201279,52301288,52202298,and 22208262)the Natural Science Foundation of Shaanxi Province(No.2023-JC-ZD-21)+1 种基金the Key Research and Development Plan of Shaanxi Province(No.2023GXLH-046)the Science and Technology Project of Xi'an(No.2021SFGX0004)。
文摘Simultaneous integration of rich oxygen vacancies(OVs)and twin crystals in a photocatalyst can not only significantly enhance the near-infrared(NIR)light response but also greatly improve the photocharge separation and transfer efficiency owing to the induced high electrical conductivity and strong built-in electric field.However,thus far,there has been a lack of a model catalyst containing both twin crystals and OVs.Herein,we develop a simple wet chemical strategy for synthesizing of unprecedented NIR light-responsive OVs-rich Cu_(2)O black nanoparticles with high-density of twin crystals(denoted as black twinned Cu_(2)O).As expected,the black twinned Cu_(2)O exhibits higher visible-NIR and NIR light-driven photodegradation of tetracycline(TC)solution than the counterparts.Significantly,the mechanism insight into twin-dependent photocatalysis in NIR light-responsive Cu_(2)O black nanocrystals with rich OVs is uncovered in depth by density functional theory(DFT)calculations and a series of experimental evidence.Expectantly,this work would be beneficial for the scientific researchers currently focusing on the NIR light-responsive photocatalysis and twin engineering of photocatalysts.
基金Funded by the National Natural Science Foundation of China(No.50902108)。
文摘Bi/Bi_(2)Fe_(4)O_(9)nanocomposites consisting of Bi_(2)Fe_(4)O_(9)nanosheets decorated with Bi nanodots were synthesized by a hydrothermal method.The formation of Bi nanodots on the Bi_(2)Fe_(4)O_(9)nanosheet surfaces was attributed to the reducibility of 2-methoxyethanol in the precursor solution.Comparative photocatalytic evaluation reveals that the Bi/Bi_(2)Fe_(4)O_(9)nanocomposites significantly enhance the degradation efficiency(99.0%)of bisphenol A compared with Bi_(2)Fe_(4)O_(9)nanosheets(64.2%)under 120 min simulated solar irradiation.This remarkable enhancement can be attributed to the established Bi/Bi_(2)Fe_(4)O_(9)heterojunction structure,which effectively facilitates the separation of photogenerated electron-hole pairs and accelerates interfacial charge transfer between the metallic Bi nanodots and semiconductor Bi_(2)Fe_(4)O_(9)nanosheets.The synergistic effects arising from this unique architecture ultimately lead to superior photocatalytic performance.
基金supported by the Leading Edge Technology of Jiangsu Province(BK20222009-X.Z.,BK20202008-X.Z.)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)National Undergraduate Innovation Training Program of NUAA(202410287179Y).
文摘Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn^(2+)hinder their development.Herein,we present a highperformance thermal charging cell design using Zn^(2+)/NH_(4)^(+)hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH_(4)^(+).Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K^(-1)and an excellent normalized power density of 19.6 mW m^(-2)K^(-2)at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.
基金financially supported by the National Science & Technology Fundamental Resources Investigation Project of China (2021FY100501)the Youth Innovation of Chinese Academy of Agricultural Sciences (Y2023QC16)。
文摘Long-term manure application has the potential to alleviate soil acidification, and increase carbon sequestration and nutrient availability, thus improving cropland fertility. However, the mechanisms behind greenhouse gas N_(2)O emissions from acidic soil mediated by long-term manure application remain poorly understood. Herein, we investigated N_(2)O emission and its linkage with gross N mineralization and nitrification rates, as well as nitrifying and denitrifying microbes in an acidic upland soil subjected to 36-year fertilization treatments, including an unfertilized control(CK), inorganic fertilizer(F), 2× rate of inorganic fertilizer(2F), manure(M), and the combination of inorganic fertilizer and manure(FM) treatments. Compared to the CK treatment(1.34 μg N kg^(-1) d^(-1)), fertilization strongly increased N_(2)O emissions by 34-fold on average, with more pronounced increases in the manure-amendment(10.6-169 μg N kg^(-1) d^(-1)) than those in the inorganic fertilizer treatments(3.26-5.51 μg N kg^(-1) d^(-1)). The manure amendment-stimulated N_(2)O emissions were highly associated with increased soil pH, mean weight diameter of soil aggregates, substrate availability(e.g., particulate organic carbon, NO_(3)^(-)and available phosphorus), gross N mineralization rates, denitrifier abundances and the(nirK+nirS)/nosZ ratio. These findings suggest that the increased N_(2)O emissions primarily resulted from alleviated acidification, increased substrate availability and improved soil structure, thus enhancing microbial N mineralization and favoring N_(2)O^(-)producing denitrifiers over N_(2)O consumers. Moreover, ammonia-oxidizing bacteria(AOB) rather than ammonia-oxidizing archaea(AOA) positively correlated with soil NO_(3)^(-)concentration and N_(2)O emissions, indicating that nitrification indirectly contributed to N_(2)O production by supplying NO_(3)^(-)for denitrification. Collectively, manure amendment potentially stimulates N_(2)O emissions, primarily resulting from alleviated soil acidification and increased substrate availability, thus enhancing N mineralization and denitrifier-mediated N_(2)O production. Our findings suggest that consideration should be given to the greenhouse gas budgets of agricultural ecosystems when applying manure for managing the pH and fertility of acidic soils.
