Currently,multistage hydraulic fracturing is the primary method for shale oil development.However,it has significant environmental drawbacks including large volumes of wastewater,greenhouse gas emissions,and toxic air...Currently,multistage hydraulic fracturing is the primary method for shale oil development.However,it has significant environmental drawbacks including large volumes of wastewater,greenhouse gas emissions,and toxic air pollutants,primarily due to high energy and water consumption as well as the use of chemical additives.In addition,the primary depletion method after multistage hydraulic fracturing can yield oil recovery factors of only a few percent.Therefore,there is an urgent need to develop cleaner and more sustainable methods for shale oil recovery.Currently,mainly some huff-and-puff enhanced oil recovery(EOR)methods without fracturing shale oil samples are being investigated.In this study,we managed to successfully investigate the feasibility of CO_(2) and hydrocarbongas(HCG)injection as a cleaner and greener method for ultra-tight shale oil development without fracturing through core flooding experiments combined with X-ray scanning in a continuous injection mode.The results show that continuous CO_(2) and HCG gas injection yielded a maximum of 75%oil recovery without significant asphaltene precipitation or permeability reduction.A piston-like displacement front was observed during miscible HcG flooding.A two-stage displacement process was observed:the first stage is controlled by miscible gas displacement where pore filling is dominated by the occurrence of snap-off The second stage is a diffusion-driven displacement where molecular diffusion plays a more important role with subsequent oil swelling and viscosity reduction after diffusive mixing.The findings not only prove the feasibility of gas injection(CO_(2) and HCG)for developing ultra-tight shale oil without fracturing but also contribute to enriching the theory of gas flooding mechanisms.展开更多
Development of ratiometric fluorescent probes for Cu^(2+)in aqueous solutions and biological systems remains the challenging task,given that Cu^(2+)commonly acts as an efficient fluorescence quencher.In this work,a no...Development of ratiometric fluorescent probes for Cu^(2+)in aqueous solutions and biological systems remains the challenging task,given that Cu^(2+)commonly acts as an efficient fluorescence quencher.In this work,a novel dyad compound NI-SP bearing energy donor naphthalimide and energy acceptor styrylpyridine chromophore has been prepared using azide-alkyne click reaction.The photophysical properties of NI-SP and its coordination with Cu^(2+)have been investigated by the absorption and fluorescent spectroscopy.Upon addition of Cu^(2+)to a solution of NI-SP,the long wavelength emission peak of styrylpyridine(600 nm)was quenched,whereas the fluorescence of naphthalimide(450 nm)was enhanced due to a decrease in resonance energy transfer efficiency between the chromophores in the(NI-SP)·Cu^(2+)complex.The observed spectral changes enable ratiometric detection of Cu^(2+)by the registration of the ratio of fluorescence intensities I450/I600.The probe exhibited high selectivity toward Cu^(2+)in the tested conditions.The detection limit was determined at 120 nmol·L^(-1),and the stability constant for(NI-SP)·Cu^(2+)was found to be 3.0×10^(6)L·mol^(-1).Bioimaging experiments showed the NI-SP could penetrate human lung adenocarcinoma A549 cells,accumulate in mitochondria,and respond to the presence of Cu^(2+)via the changes in the fluorescence intensity of styrylpyridine fragment.展开更多
Covalent metal-organic frameworks(CMOFs)combining the chemistry of metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)have demonstrated promising potential as reticular photocatalysts,owing to their tu...Covalent metal-organic frameworks(CMOFs)combining the chemistry of metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)have demonstrated promising potential as reticular photocatalysts,owing to their tunable structures,high surface areas,and efficient light absorption,which provide enhanced charge separation and improved catalytic activity.Herein,we report three imine-linked CMOFs constructed by Cu(I)cyclic trinuclear units(CTUs)and organic linkers with tunable conjugated functional groups,such as benzene(JNM-61),naphthalene(JNM-62),or anthracene(JNM-63),via dynamic covalent chemistry.Due to the incorporation of conjugated linkers,the obtained CMOFs exhibited good photocatalytic activity for the cross-dehydrocoupling reaction of N-phenyl-tetrahydroisoquinoline with alkynes.Interestingly,the variation of linker conjugation strongly influences the light absorption,charge separation and reactive oxygen species(ROS)generation of the materials,resulting in significantly controlled photocatalytic efficiency.Notably,JNM-63 with anthracene linkers showed more efficient photocatalytic performance than JNM-61 containing benzene units and JNM-62 containing naphthalene moieties,suggesting the extended conjugation enhanced the oxygen activation and electron transfer during the photocatalytic process.This work presents a simple yet effect approach to optimizing reticular photocatalysts via dynamic covalent chemistry.展开更多
基金supported by the Ministry of Science and Higher Education of the Russian Federation under agreement No.075-10-2022-011 within the framework of the development program for a world-class Research Center.
文摘Currently,multistage hydraulic fracturing is the primary method for shale oil development.However,it has significant environmental drawbacks including large volumes of wastewater,greenhouse gas emissions,and toxic air pollutants,primarily due to high energy and water consumption as well as the use of chemical additives.In addition,the primary depletion method after multistage hydraulic fracturing can yield oil recovery factors of only a few percent.Therefore,there is an urgent need to develop cleaner and more sustainable methods for shale oil recovery.Currently,mainly some huff-and-puff enhanced oil recovery(EOR)methods without fracturing shale oil samples are being investigated.In this study,we managed to successfully investigate the feasibility of CO_(2) and hydrocarbongas(HCG)injection as a cleaner and greener method for ultra-tight shale oil development without fracturing through core flooding experiments combined with X-ray scanning in a continuous injection mode.The results show that continuous CO_(2) and HCG gas injection yielded a maximum of 75%oil recovery without significant asphaltene precipitation or permeability reduction.A piston-like displacement front was observed during miscible HcG flooding.A two-stage displacement process was observed:the first stage is controlled by miscible gas displacement where pore filling is dominated by the occurrence of snap-off The second stage is a diffusion-driven displacement where molecular diffusion plays a more important role with subsequent oil swelling and viscosity reduction after diffusive mixing.The findings not only prove the feasibility of gas injection(CO_(2) and HCG)for developing ultra-tight shale oil without fracturing but also contribute to enriching the theory of gas flooding mechanisms.
基金support from the Russian Science Foundation(Grant No.20-73-10186-P)the Ministry of Science and Higher Education of the Russian Federation(project FSSM-2023-0003)for optical spectroscopy studies。
文摘Development of ratiometric fluorescent probes for Cu^(2+)in aqueous solutions and biological systems remains the challenging task,given that Cu^(2+)commonly acts as an efficient fluorescence quencher.In this work,a novel dyad compound NI-SP bearing energy donor naphthalimide and energy acceptor styrylpyridine chromophore has been prepared using azide-alkyne click reaction.The photophysical properties of NI-SP and its coordination with Cu^(2+)have been investigated by the absorption and fluorescent spectroscopy.Upon addition of Cu^(2+)to a solution of NI-SP,the long wavelength emission peak of styrylpyridine(600 nm)was quenched,whereas the fluorescence of naphthalimide(450 nm)was enhanced due to a decrease in resonance energy transfer efficiency between the chromophores in the(NI-SP)·Cu^(2+)complex.The observed spectral changes enable ratiometric detection of Cu^(2+)by the registration of the ratio of fluorescence intensities I450/I600.The probe exhibited high selectivity toward Cu^(2+)in the tested conditions.The detection limit was determined at 120 nmol·L^(-1),and the stability constant for(NI-SP)·Cu^(2+)was found to be 3.0×10^(6)L·mol^(-1).Bioimaging experiments showed the NI-SP could penetrate human lung adenocarcinoma A549 cells,accumulate in mitochondria,and respond to the presence of Cu^(2+)via the changes in the fluorescence intensity of styrylpyridine fragment.
基金G.H.N.is thankful for the financial support from Guangzhou Science and Technology Project(202201020038)supported financially by the National Natural Science Foundation of China(Nos.22471097,22371091,21975104,22150004 and 22101099)+1 种基金the Guangdong Major Project of Basic and Applied Research(No.2019B030302009)the Open Fund of Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Chemistry(No.2020B121201005).
文摘Covalent metal-organic frameworks(CMOFs)combining the chemistry of metal-organic frameworks(MOFs)and covalent organic frameworks(COFs)have demonstrated promising potential as reticular photocatalysts,owing to their tunable structures,high surface areas,and efficient light absorption,which provide enhanced charge separation and improved catalytic activity.Herein,we report three imine-linked CMOFs constructed by Cu(I)cyclic trinuclear units(CTUs)and organic linkers with tunable conjugated functional groups,such as benzene(JNM-61),naphthalene(JNM-62),or anthracene(JNM-63),via dynamic covalent chemistry.Due to the incorporation of conjugated linkers,the obtained CMOFs exhibited good photocatalytic activity for the cross-dehydrocoupling reaction of N-phenyl-tetrahydroisoquinoline with alkynes.Interestingly,the variation of linker conjugation strongly influences the light absorption,charge separation and reactive oxygen species(ROS)generation of the materials,resulting in significantly controlled photocatalytic efficiency.Notably,JNM-63 with anthracene linkers showed more efficient photocatalytic performance than JNM-61 containing benzene units and JNM-62 containing naphthalene moieties,suggesting the extended conjugation enhanced the oxygen activation and electron transfer during the photocatalytic process.This work presents a simple yet effect approach to optimizing reticular photocatalysts via dynamic covalent chemistry.
