Selective conversion of fructose to 1,2-propanediol(1,2-PDO)is considered as a sustainable and cost-effective alternative to petroleum-based processes,however,this approach still faces challenges associated with low e...Selective conversion of fructose to 1,2-propanediol(1,2-PDO)is considered as a sustainable and cost-effective alternative to petroleum-based processes,however,this approach still faces challenges associated with low efficiency and harsh reaction conditions.Here,we have successfully synthesized a novel bifunctional Ru-WO_(x)-MgO_(y) catalyst through a facile'one-pot'solvothermal method.Remarkably,this catalyst exhibits exceptional catalytic performances in the conversion of fructose to 1,2-PDO under mild reaction conditions.The yield of 1,2-PDO is up to 56.2%at 140°C for 4 h under an ultra-low hydrogen pressure of only 0.2 MPa,surpassing the reported results in recent literature(below 51%).Comprehensive characterizations and density functional theory(DFT)calculations reveal that the presence of oxygen vacancies in the Ru-WO_(x)-MgO_(y) catalyst,serving as active acidic sites,facilitates the chemoselective cleavage of C-C bonds in fructose,which leads to the generation of active intermediates and ultimately resulted in the high yield of 1,2-PDO.展开更多
In the face of fierce market competition,enterprises must ensure the competitiveness of their products or services through technological innovation.However,the complexity of technology often surpasses the capabilities...In the face of fierce market competition,enterprises must ensure the competitiveness of their products or services through technological innovation.However,the complexity of technology often surpasses the capabilities of individual enterprises,leading them to deepen cooperation with other organizations.The entities within the enterprise innovation ecosystem depend on each other,collaborate closely,and rely on core enterprises to integrate resources,thereby creating system value and enhancing competitiveness.The purpose of this paper is to explore the process of selecting appropriate ecosystem partners.It begins by providing an overview of relevant concepts,characteristics,selection factors,and methods.Subsequently,it analyzes the roles,resources,and synergy evolution of the entities within the ecosystem.An evaluation system encompassing operation,core,synergy,and development capability is then established.This system comprises 16 indicators,including organization scale and reputation,and is accompanied by a hierarchical evaluation model.Finally,the validity of the evaluation system is confirmed through empirical analysis,utilizing the Analytic Hierarchy Process(AHP)and the fuzzy comprehensive evaluation method.展开更多
Liver injury has become a serious liver disease worldwide,and its incidence is increasing year by year,bringing a serious health burden to people in all countries.Tetrahydrocurcumin is an active metabolite of curcumin...Liver injury has become a serious liver disease worldwide,and its incidence is increasing year by year,bringing a serious health burden to people in all countries.Tetrahydrocurcumin is an active metabolite of curcumin,which has pharmacological effects such as antioxidant,anti-inflammatory,inhibition of apoptosis,anti-tumor,and anti-aging,and it can inhibit apoptosis in liver cells under the state of hepatic injury and reduce the level of oxidative stress and inflammation in liver tissues through the signaling pathways such as MAPK,PI3K/Akt,PPAR,AMPK,and Nrf2 to prevent and control liver injury.The purpose of preventing and controlling liver injury can be achieved.The active structure,pharmacological effects and application of tetrahydrocurcumin in liver injury were summarized by reviewing domestic and international literature,with a view to providing reference for further research on tetrahydrocurcumin in the field of liver injury.展开更多
The relationship between precipitation intensity and cloud water in typhoon systems remains unclear.This study combined time-and space-synchronized precipitation and spectral data obtained by the Precipitation Radar(P...The relationship between precipitation intensity and cloud water in typhoon systems remains unclear.This study combined time-and space-synchronized precipitation and spectral data obtained by the Precipitation Radar(PR)as well as the Visible and Infrared Scanner(VIRS)onboard the TRMM satellite,to overcome the limitations of precipitation properties and cloud parameters not being synchronized in previous studies.A merged dataset of near-surface rain rate(RR)and corresponding cloud water path(CWP)was established and used to analyze the potential correlation between cloud microphysical properties and precipitation,to deepen our understanding of the evolution of cloud to rain.In addition,25 collocated satellite overpasses of mature typhoon cases in the Northwest Pacific Ocean from 1998 to 2012 were obtained,and the relationships between the CWP and RR of 144515 pixels were analyzed in detail.The results show that the CWP and RR of mature typhoon systems with different precipitation types,precipitation cloud phases,and vertical depths of precipitation can be fitted by a notable sigmoid function,which may be useful for estimating CWP and parameterizing precipitation in models.Furthermore,the relationship was applied and tested with an independent sample to show that RR is a significant indicator of CWP.展开更多
Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10(PTEN)gene in cancer cells may be associated with immunosuppressive tumor microenvironment(TME)and poor respon...Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10(PTEN)gene in cancer cells may be associated with immunosuppressive tumor microenvironment(TME)and poor response to immune checkpoint blockade(ICB)therapy.Therefore,efficiently restoring PTEN gene expression in cancer cells is critical to improving the responding rate to ICB therapy.Here,we screened an adeno-associated virus(AAV)capsid for efficient PTEN gene delivery into B16F10 tumor cells.We demonstrated that intratumorally injected AAV6-PTEN successfully restored the tumor cell PTEN gene expression and effectively inhibited tumor progression by inducing tumor cell immunogenic cell death(ICD)and increasing immune cell infiltration.Moreover,we developed an anti-PD-1 loaded phospholipid-based phase separation gel(PPSG),which formed an in situ depot and sustainably release anti-PD-1 drugs within 42 days in vivo.In order to effectively inhibit the recurrence of melanoma,we further applied a triple therapy based on AAV6-PTEN,PPSG^(@anti-PD-1)and CpG,and showed that this triple therapy strategy enhanced the synergistic antitumor immune effect and also induced robust immune memory,which completely rejected tumor recurrence.We anticipate that this triple therapy could be used as a new tumor combination therapy with stronger immune activation capacity and tumor inhibition efficacy.展开更多
Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines,the epidemic prevention and control are still challenging.Here,we employ a capsid and antige...Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines,the epidemic prevention and control are still challenging.Here,we employ a capsid and antigen structure engineering(CASE)strategy to manufacture an adenoassociated viral serotype 6-based vaccine(S663V-RBD),which expresses trimeric receptor binding domain(RBD)of spike protein fused with a biological adjuvant RS09.Impressively,the engineered S663V-RBD could rapidly induce a satisfactory RBD-specific IgG titer within 2 weeks and maintain the titer for more than 4 months.Compared to the licensed BBIBP-CorV(Sinopharm,China),a single-dose S663V-RBD induced more endurable and robust immune responses in mice and elicited superior neutralizing antibodies against three typical SARS-CoV-2 pseudoviruses including wild type,C.37(Lambda)and B.1.617.2(Delta).More interestingly,the intramuscular injection of S663V-RBD could overcome pre-existing immunity against the capsid.Given its effectiveness,the CASE-based S663VRBD may provide a new solution for the current and next pandemic.展开更多
This study aims to investigate the influence of CO_(2)-mixing dose(mass fractions of 0.3%,0.6%,and 0.9%)and prolonged mixing time on the fresh and hardened properties of cement pastes.The CO_(2)-mixing can act as coag...This study aims to investigate the influence of CO_(2)-mixing dose(mass fractions of 0.3%,0.6%,and 0.9%)and prolonged mixing time on the fresh and hardened properties of cement pastes.The CO_(2)-mixing can act as coagulant in fresh cement mixtures,resulting in a significant reduction in workability associated with the formation of a rich calcium carbonate network on the surface of cement particles.The CO_(2)-mixing cement pastes were found to be much stiffer and more difficult to handle,place,and compact than the control mixture,which had a negative effect on the mechanical strength performance of the hardened pastes.However,prolonging the mixing time for 1 min(immediately after CO_(2)-mixing)can effectively improve the workability(by~53%–85%)by breaking up the flocculation network of deposited calcium carbonates.As a result,the presence of detached calcium carbonate accelerated early cement hydration and densified the microstructure;this improved early-age compressive strength by~6%–32%,depending on the CO_(2)-mixing dose used.Therefore,it seems that the CO_(2)-mixing dose should be controlled at≤0.6%with the mixing time prolonged in order to attain satisfactory workability and mechanical strength.展开更多
Inherently chiral 6,7-diphenyldibenzo[e,g][1,4]diazocine(DDD)has been synthesized enantioselectively for the first time via chiral phosphoric acid(CPA)-catalyzed cyclocondensation of readily available[1,1′-biphenyl]-...Inherently chiral 6,7-diphenyldibenzo[e,g][1,4]diazocine(DDD)has been synthesized enantioselectively for the first time via chiral phosphoric acid(CPA)-catalyzed cyclocondensation of readily available[1,1′-biphenyl]-2,2′-diamine(1a)and benzil(2a)in 82%yield,with 98%ee under mild reaction conditions.The strategy could also be applied to racemic biaryl diamines through kinetic resolution.The unexpectedly high interconversion energy barriers between the enantiomers(ΔG=39.5 kcal/mol)and the chemical stability rendered DDD an ideal platform for developing new chiral ligands and catalysts.Unique inherently chiralDDD-based phosphoramidites,phosphoric acid,mono-and diphosphine ligands were prepared from optically pure diphenol derivative DDDOL as a common precursor.Preliminary asymmetric reactions catalyzed by Pd or Rh in the presence of newly developed ligands exhibited comparable or even better enantioselectivities than the corresponding BINOLor SPINOL-derived ligands.Density functional theory calculation revealed the origin of the enantioselectivity during the process.展开更多
Enhancement of supercapacitors(SCs)with high-energy density and high-power density is still a great challenge.In this paper,a facile strategy for in situ anchoring of Co_(3)O_(4) particles on N doped carbon cloth(pCoN...Enhancement of supercapacitors(SCs)with high-energy density and high-power density is still a great challenge.In this paper,a facile strategy for in situ anchoring of Co_(3)O_(4) particles on N doped carbon cloth(pCoNCC)is reported.Due to the interaction of the doped N and Co_(3)O_(4),the electrochemical performance improves significantly,reaching 1,940.13 mF·cm^(−2) at 1 mA·cm^(−2) and energy density of 172.46μWh·cm^(−2) at the power density of 400μW·cm^(−2),much larger than that without N doping electrode of 28.5 mF·cm^(−2).An aqueous symmetric supercapacitor(ASSC)assembled by two pCoNCC electrodes achieves a maximum energy density of 447.42μWh·cm^(−2) and a highest power density of 8,000μW·cm^(−2).Utilizing such a high-energy storage ASSC,a digital watch and a temperature-humidity detector are powered for nearly 1 and 2 h,respectively.Moreover,the ASSC displays a superb electrochemical stability of 87.7%retention after 10,000 cycles at 40 mA·cm^(−2).This work would provide a new sight to enhance active materials performance and be beneficial for the future energy storage and supply systems.展开更多
To obtain symmetric supercapacitors(SCs)with high energy density,it is critical to fabricate an electrode with wide potential window and excellent capacitive performance.Herein,by using the strong double hydrolysis re...To obtain symmetric supercapacitors(SCs)with high energy density,it is critical to fabricate an electrode with wide potential window and excellent capacitive performance.Herein,by using the strong double hydrolysis reaction between anions and cations,the FeOOH nanosheets on the surface of activated carbon cloth(FeOOH@AC)are prepared through a simple hydrothermal process.The FeOOH@AC electrode exhibits maximum capacitance of 4,090 mF·cm^−2 at wider potential window-1–0 V and 3,250 mF·cm^−2 at 0–1 V versus SCE in 2 M LiNO3 electrolyte.With two pieces of FeOOH@AC electrodes the obtained symmetric SC can operate at the voltage window of 2 V.This FeOOH symmetric SC shows high energy density of 13.261 mWh·cm^−3 at a power density of 14.824 mW·cm^−3 and maintains 4.175 mWh·cm^−3 at a maximum power density of 118.564 mW·cm^−3,as well as excellent charge storage capacity and cyclic stability.Li ion adsorption and diffusion mechanism on the(200)facets of FeOOH are explained by the density functional theory(DFT)calculations.The simple synthesis process and excellent capacitance performance of the FeOOH@AC composite make it a very promising candidate for high performance symmetric SC electrodes.展开更多
A new kind of intermolecular indole C–H amidation reaction catalyzed by the most frequently used palladium catalyst has been developed.Sulfonyl azide was employed as an innovative nitrogen source and environmentally ...A new kind of intermolecular indole C–H amidation reaction catalyzed by the most frequently used palladium catalyst has been developed.Sulfonyl azide was employed as an innovative nitrogen source and environmentally benign nitrogen was produced as the only byproduct.展开更多
An unprecedented tandem carbonylation/aminocarbonylation triggered by palladium-catalyzed enantio-selective Heck-type exocyclopalladation delivering chiral heterocyclicα-ketoamides has been developed.The uncommon dou...An unprecedented tandem carbonylation/aminocarbonylation triggered by palladium-catalyzed enantio-selective Heck-type exocyclopalladation delivering chiral heterocyclicα-ketoamides has been developed.The uncommon double CO insertion into theσ-alkylpalladium intermediate takes place selectively under atmospheric pressure of CO using alkylamine as the nucleophile.Unique structures hybridizing alkylα-ketoamides with indolin-2-one containing a C3 all-carbon quaternary stereogenic center and 5,7-dihydro-6H-dibenzo[b,d]azepin-6-one containing a thermodynamically stabilized stereogenic biaryl axis are produced in good yields with excellent enantio-and/or diastereoselectivities.展开更多
(Z)-7-Aryl-5-acyldibenzo[e,g][1,4]diazocin-6(5H)-one,a unique saddle-shaped bridged biaryl containing synchronized aryl–aryl and N-aryl stereogenic axes,was constructed for the first time in good yields with up to 96...(Z)-7-Aryl-5-acyldibenzo[e,g][1,4]diazocin-6(5H)-one,a unique saddle-shaped bridged biaryl containing synchronized aryl–aryl and N-aryl stereogenic axes,was constructed for the first time in good yields with up to 96%enantiomeric excess(ee).The threecomponent coupling reaction,involving aryl iodide,2,2′-diisocyano-1,1′-biphenyl,and carboxylate,constructs the eight-membered ring in an atroposelective manner through palladium-catalyzed double isocyanide insertion followed by C–Obond formation during reductive elimination and amide formation after acyl transfer.展开更多
基金the financial support from the Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX0458)the State Key Laboratory of Coal Mine Disaster Dynamics and Control(2011DA105287-MS202203)+4 种基金the Joint Fund for Innovation and Development of Chongqing(CSTB2022NSCQ-LZX0030)the financial support from the National Natural Science Foundation of China(22168027 and 22308169)the financial support from the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0741)the financial support from the National Natural Science Foundation of China(22105028)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0572)。
文摘Selective conversion of fructose to 1,2-propanediol(1,2-PDO)is considered as a sustainable and cost-effective alternative to petroleum-based processes,however,this approach still faces challenges associated with low efficiency and harsh reaction conditions.Here,we have successfully synthesized a novel bifunctional Ru-WO_(x)-MgO_(y) catalyst through a facile'one-pot'solvothermal method.Remarkably,this catalyst exhibits exceptional catalytic performances in the conversion of fructose to 1,2-PDO under mild reaction conditions.The yield of 1,2-PDO is up to 56.2%at 140°C for 4 h under an ultra-low hydrogen pressure of only 0.2 MPa,surpassing the reported results in recent literature(below 51%).Comprehensive characterizations and density functional theory(DFT)calculations reveal that the presence of oxygen vacancies in the Ru-WO_(x)-MgO_(y) catalyst,serving as active acidic sites,facilitates the chemoselective cleavage of C-C bonds in fructose,which leads to the generation of active intermediates and ultimately resulted in the high yield of 1,2-PDO.
基金The 2022 Sichuan Tourism Development Research Center General Project“A Study on the Perceived Evaluation and Differences of Tourism Supply between Tourists and Local Residents along the Sichuan Tibet Railway”(Project number:LY22-25)。
文摘In the face of fierce market competition,enterprises must ensure the competitiveness of their products or services through technological innovation.However,the complexity of technology often surpasses the capabilities of individual enterprises,leading them to deepen cooperation with other organizations.The entities within the enterprise innovation ecosystem depend on each other,collaborate closely,and rely on core enterprises to integrate resources,thereby creating system value and enhancing competitiveness.The purpose of this paper is to explore the process of selecting appropriate ecosystem partners.It begins by providing an overview of relevant concepts,characteristics,selection factors,and methods.Subsequently,it analyzes the roles,resources,and synergy evolution of the entities within the ecosystem.An evaluation system encompassing operation,core,synergy,and development capability is then established.This system comprises 16 indicators,including organization scale and reputation,and is accompanied by a hierarchical evaluation model.Finally,the validity of the evaluation system is confirmed through empirical analysis,utilizing the Analytic Hierarchy Process(AHP)and the fuzzy comprehensive evaluation method.
基金supported by Key Program of Natural Science Foundation of Sichuan Province of China(2023NSFSC0040).
文摘Liver injury has become a serious liver disease worldwide,and its incidence is increasing year by year,bringing a serious health burden to people in all countries.Tetrahydrocurcumin is an active metabolite of curcumin,which has pharmacological effects such as antioxidant,anti-inflammatory,inhibition of apoptosis,anti-tumor,and anti-aging,and it can inhibit apoptosis in liver cells under the state of hepatic injury and reduce the level of oxidative stress and inflammation in liver tissues through the signaling pathways such as MAPK,PI3K/Akt,PPAR,AMPK,and Nrf2 to prevent and control liver injury.The purpose of preventing and controlling liver injury can be achieved.The active structure,pharmacological effects and application of tetrahydrocurcumin in liver injury were summarized by reviewing domestic and international literature,with a view to providing reference for further research on tetrahydrocurcumin in the field of liver injury.
基金the National Natural Science Foundation of China(grant no.91837310,41675041,41705011)the National Key R&D Program of China(2018YFC1507200,2017YFC1501402)+2 种基金the Key research and development projects in Anhui province(201904a07020099)the Third Tibetan Plateau Scientific Experiment:Observations for Boundary Layer and Troposphere(Grant No.GYHY201406001)CLIMATE-TPE(ID 32070)in the framework of the ESA-MOST Dragon 4 program.
文摘The relationship between precipitation intensity and cloud water in typhoon systems remains unclear.This study combined time-and space-synchronized precipitation and spectral data obtained by the Precipitation Radar(PR)as well as the Visible and Infrared Scanner(VIRS)onboard the TRMM satellite,to overcome the limitations of precipitation properties and cloud parameters not being synchronized in previous studies.A merged dataset of near-surface rain rate(RR)and corresponding cloud water path(CWP)was established and used to analyze the potential correlation between cloud microphysical properties and precipitation,to deepen our understanding of the evolution of cloud to rain.In addition,25 collocated satellite overpasses of mature typhoon cases in the Northwest Pacific Ocean from 1998 to 2012 were obtained,and the relationships between the CWP and RR of 144515 pixels were analyzed in detail.The results show that the CWP and RR of mature typhoon systems with different precipitation types,precipitation cloud phases,and vertical depths of precipitation can be fitted by a notable sigmoid function,which may be useful for estimating CWP and parameterizing precipitation in models.Furthermore,the relationship was applied and tested with an independent sample to show that RR is a significant indicator of CWP.
基金This study was supported by National Natural Science Foundation of China(Grant Nos.81925036,China)the Key Research and Development Program of Science and Technology Department of Sichuan Province(Grant No.2020YFS0570,China)111 project(Grant No.B18035,China).
文摘Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10(PTEN)gene in cancer cells may be associated with immunosuppressive tumor microenvironment(TME)and poor response to immune checkpoint blockade(ICB)therapy.Therefore,efficiently restoring PTEN gene expression in cancer cells is critical to improving the responding rate to ICB therapy.Here,we screened an adeno-associated virus(AAV)capsid for efficient PTEN gene delivery into B16F10 tumor cells.We demonstrated that intratumorally injected AAV6-PTEN successfully restored the tumor cell PTEN gene expression and effectively inhibited tumor progression by inducing tumor cell immunogenic cell death(ICD)and increasing immune cell infiltration.Moreover,we developed an anti-PD-1 loaded phospholipid-based phase separation gel(PPSG),which formed an in situ depot and sustainably release anti-PD-1 drugs within 42 days in vivo.In order to effectively inhibit the recurrence of melanoma,we further applied a triple therapy based on AAV6-PTEN,PPSG^(@anti-PD-1)and CpG,and showed that this triple therapy strategy enhanced the synergistic antitumor immune effect and also induced robust immune memory,which completely rejected tumor recurrence.We anticipate that this triple therapy could be used as a new tumor combination therapy with stronger immune activation capacity and tumor inhibition efficacy.
基金the National Natural Science Foundation of China,China(Grant Nos.81925036 and 81872814)the Key Research and Development Program of Science and Technology Department of Sichuan Province,China(Grant No.2020YFS0570)+1 种基金111 project,China(Grant No.B18035)the Fundamental Research Funds for the Central Universities,China。
文摘Due to the insufficient long-term protection and significant efficacy reduction to new variants of current COVID-19 vaccines,the epidemic prevention and control are still challenging.Here,we employ a capsid and antigen structure engineering(CASE)strategy to manufacture an adenoassociated viral serotype 6-based vaccine(S663V-RBD),which expresses trimeric receptor binding domain(RBD)of spike protein fused with a biological adjuvant RS09.Impressively,the engineered S663V-RBD could rapidly induce a satisfactory RBD-specific IgG titer within 2 weeks and maintain the titer for more than 4 months.Compared to the licensed BBIBP-CorV(Sinopharm,China),a single-dose S663V-RBD induced more endurable and robust immune responses in mice and elicited superior neutralizing antibodies against three typical SARS-CoV-2 pseudoviruses including wild type,C.37(Lambda)and B.1.617.2(Delta).More interestingly,the intramuscular injection of S663V-RBD could overcome pre-existing immunity against the capsid.Given its effectiveness,the CASE-based S663VRBD may provide a new solution for the current and next pandemic.
基金supported by the Science and Technology Innovation Plan of Hunan Province(No.2022WZ1010)the Program Fund of Non-Metallic Excellence and Innovation Center for Building Materials(No.2023Ph.D-6),China.
文摘This study aims to investigate the influence of CO_(2)-mixing dose(mass fractions of 0.3%,0.6%,and 0.9%)and prolonged mixing time on the fresh and hardened properties of cement pastes.The CO_(2)-mixing can act as coagulant in fresh cement mixtures,resulting in a significant reduction in workability associated with the formation of a rich calcium carbonate network on the surface of cement particles.The CO_(2)-mixing cement pastes were found to be much stiffer and more difficult to handle,place,and compact than the control mixture,which had a negative effect on the mechanical strength performance of the hardened pastes.However,prolonging the mixing time for 1 min(immediately after CO_(2)-mixing)can effectively improve the workability(by~53%–85%)by breaking up the flocculation network of deposited calcium carbonates.As a result,the presence of detached calcium carbonate accelerated early cement hydration and densified the microstructure;this improved early-age compressive strength by~6%–32%,depending on the CO_(2)-mixing dose used.Therefore,it seems that the CO_(2)-mixing dose should be controlled at≤0.6%with the mixing time prolonged in order to attain satisfactory workability and mechanical strength.
基金the National Natural Science Foundation of China(grant nos.21871268 and 22071250)the Natural Science Foundation of Guangdong Province of China(grant no.2020A1515011428)the“BAGUI Scholar”Program of Guangxi Province of China,and the SKLRD Project(grant no.SKLRD-Z-202014)for financial support.
文摘Inherently chiral 6,7-diphenyldibenzo[e,g][1,4]diazocine(DDD)has been synthesized enantioselectively for the first time via chiral phosphoric acid(CPA)-catalyzed cyclocondensation of readily available[1,1′-biphenyl]-2,2′-diamine(1a)and benzil(2a)in 82%yield,with 98%ee under mild reaction conditions.The strategy could also be applied to racemic biaryl diamines through kinetic resolution.The unexpectedly high interconversion energy barriers between the enantiomers(ΔG=39.5 kcal/mol)and the chemical stability rendered DDD an ideal platform for developing new chiral ligands and catalysts.Unique inherently chiralDDD-based phosphoramidites,phosphoric acid,mono-and diphosphine ligands were prepared from optically pure diphenol derivative DDDOL as a common precursor.Preliminary asymmetric reactions catalyzed by Pd or Rh in the presence of newly developed ligands exhibited comparable or even better enantioselectivities than the corresponding BINOLor SPINOL-derived ligands.Density functional theory calculation revealed the origin of the enantioselectivity during the process.
基金This work was supported by the National Natural Science Foundation of China(Nos.51772036 and 51572040)the Fundamental Research Funds for the Central Universities(Nos.2019CDXZWL001 and 2020CDCGJ005).
文摘Enhancement of supercapacitors(SCs)with high-energy density and high-power density is still a great challenge.In this paper,a facile strategy for in situ anchoring of Co_(3)O_(4) particles on N doped carbon cloth(pCoNCC)is reported.Due to the interaction of the doped N and Co_(3)O_(4),the electrochemical performance improves significantly,reaching 1,940.13 mF·cm^(−2) at 1 mA·cm^(−2) and energy density of 172.46μWh·cm^(−2) at the power density of 400μW·cm^(−2),much larger than that without N doping electrode of 28.5 mF·cm^(−2).An aqueous symmetric supercapacitor(ASSC)assembled by two pCoNCC electrodes achieves a maximum energy density of 447.42μWh·cm^(−2) and a highest power density of 8,000μW·cm^(−2).Utilizing such a high-energy storage ASSC,a digital watch and a temperature-humidity detector are powered for nearly 1 and 2 h,respectively.Moreover,the ASSC displays a superb electrochemical stability of 87.7%retention after 10,000 cycles at 40 mA·cm^(−2).This work would provide a new sight to enhance active materials performance and be beneficial for the future energy storage and supply systems.
基金This work is supported by the National Natural Science Foundation of China(No.51572040)Fundamental Research Funds for the Central Universities(Nos.2019CDXZWL001,2018CDQYWL0046,and 2018CDPTCG0001/22)。
文摘To obtain symmetric supercapacitors(SCs)with high energy density,it is critical to fabricate an electrode with wide potential window and excellent capacitive performance.Herein,by using the strong double hydrolysis reaction between anions and cations,the FeOOH nanosheets on the surface of activated carbon cloth(FeOOH@AC)are prepared through a simple hydrothermal process.The FeOOH@AC electrode exhibits maximum capacitance of 4,090 mF·cm^−2 at wider potential window-1–0 V and 3,250 mF·cm^−2 at 0–1 V versus SCE in 2 M LiNO3 electrolyte.With two pieces of FeOOH@AC electrodes the obtained symmetric SC can operate at the voltage window of 2 V.This FeOOH symmetric SC shows high energy density of 13.261 mWh·cm^−3 at a power density of 14.824 mW·cm^−3 and maintains 4.175 mWh·cm^−3 at a maximum power density of 118.564 mW·cm^−3,as well as excellent charge storage capacity and cyclic stability.Li ion adsorption and diffusion mechanism on the(200)facets of FeOOH are explained by the density functional theory(DFT)calculations.The simple synthesis process and excellent capacitance performance of the FeOOH@AC composite make it a very promising candidate for high performance symmetric SC electrodes.
基金financially supported by the National Natural Science Foundation of China(21272233,21472190,21402203)
文摘A new kind of intermolecular indole C–H amidation reaction catalyzed by the most frequently used palladium catalyst has been developed.Sulfonyl azide was employed as an innovative nitrogen source and environmentally benign nitrogen was produced as the only byproduct.
基金We gratefully acknowledge the National Natural Science Foundation of China(21772198,21871268,22071250)the Frontier Research Program of Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory)(2018GRZ110105017)+1 种基金the Natural Science Foundation of Guangdong Province of China(2020A1515011428)the“BAGUI Scholar”Program of Guangxi Province of China for financial support and Prof.Wenjun Tang at Shanghai institute of Organic Chemistry for providing some of ligands for free.
文摘An unprecedented tandem carbonylation/aminocarbonylation triggered by palladium-catalyzed enantio-selective Heck-type exocyclopalladation delivering chiral heterocyclicα-ketoamides has been developed.The uncommon double CO insertion into theσ-alkylpalladium intermediate takes place selectively under atmospheric pressure of CO using alkylamine as the nucleophile.Unique structures hybridizing alkylα-ketoamides with indolin-2-one containing a C3 all-carbon quaternary stereogenic center and 5,7-dihydro-6H-dibenzo[b,d]azepin-6-one containing a thermodynamically stabilized stereogenic biaryl axis are produced in good yields with excellent enantio-and/or diastereoselectivities.
基金the National Natural Science Foundation of China(nos.21772198,21871268,and 22071250)the Frontier Research Program of Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory)(no.2018GRZ110105017)+2 种基金the Natural Science Foundation of Guangdong Province of China(no.2020A1515011428)the“BAGUI Scholar”Program of Guangxi Province of China,and SKLRD Open Project(no.SKLRD-Z-202014)for financial supportthe Guangzhou Branch of the Supercomputing Center of CAS for support.
文摘(Z)-7-Aryl-5-acyldibenzo[e,g][1,4]diazocin-6(5H)-one,a unique saddle-shaped bridged biaryl containing synchronized aryl–aryl and N-aryl stereogenic axes,was constructed for the first time in good yields with up to 96%enantiomeric excess(ee).The threecomponent coupling reaction,involving aryl iodide,2,2′-diisocyano-1,1′-biphenyl,and carboxylate,constructs the eight-membered ring in an atroposelective manner through palladium-catalyzed double isocyanide insertion followed by C–Obond formation during reductive elimination and amide formation after acyl transfer.