As the largest inland lake of China, along with its unique landscape and geographical location, Qinghai Lake has got much atten- tion of the scientists for a long time. The precursors have done substantive researches ...As the largest inland lake of China, along with its unique landscape and geographical location, Qinghai Lake has got much atten- tion of the scientists for a long time. The precursors have done substantive researches by using the lake sediment, which deepen our tmderstanding of the climate changes in this region. Although sand dunes and loess sediment are widely distributed around the lake, so far the researches on geochemical elements from aeolian sediment have been less reported. In this paper, we selected a typical aeolian profile on the east of Qinghai Lake. Based on systematic sampling and analysis of seven major geochemical ele- ments, combined with OSL dating and previous researches, this paper discusses climate changes in the Qinghai Lake area since 12.5 ka B.P.. Our conclusions are： （1） Before 12.5 ka B.P., the climate in this region was dry, cold, and accompanied by strong wind-sand activities. （2） During 12.5-11.9 ka B.P., the climate became warm and wet. However, there was an abrupt climate cooling event during 12.2-11.9 ka B.P., which likely corresponded to the Younger Dryas event. （3） During 11.9 8.0 ka B.P., the climate fluctuated greatly and frequently from warm to cold, and three cooling events occurred. （4） During 8.0-2.6 ka B.P., the climate was warm and humid. （5） Since 2.6 ka B.P., similar to the modem climate, the climate was mainly dry and cold.展开更多
Elemental state matter-heteroatom-doped carbon composites are of great importance for the development of anode in lithium ion batteries(LIBs).In this article,metal–organic frameworks(MOFs)are adopted as precursor to ...Elemental state matter-heteroatom-doped carbon composites are of great importance for the development of anode in lithium ion batteries(LIBs).In this article,metal–organic frameworks(MOFs)are adopted as precursor to prepare Co composites via metallurgical pyrolysis under controllable conditions.The obtained nitrogen-doped porous carbon-Co nanocomposite possesses core–shell structure(Co@C–N).Co@C–N exhibits the best Li storage performances as anode active matter.After the 200th cycles at current density of 0.2 A g^(-1),a reversible capacity of 870 mAh g^(-1)is retained.A reversible capacity of 275 mAh g^(-1)still maintains with 5 A g^(-1).Co@C–N presents a high reversible capacity with excellent cycle stability.Considering the corresponding experimental and theoretical results,the Co0-based N-doped porous carbon composite is proposed to work as LIBs anode matter.These results provide a new design idea for electrode matters of metallic ion battery,and demonstrate that MOFs pyrolysis is an effective method for the construction of elemental state anode materials.展开更多
Room temperature phosphorescence(RTP)materials show potential applications in information security and optoelectronic devices,but it is still a challenge to achieve RTP in organic materials under water ambient due to ...Room temperature phosphorescence(RTP)materials show potential applications in information security and optoelectronic devices,but it is still a challenge to achieve RTP in organic materials under water ambient due to the unstable property of triplet states.Herein,water-induced RTP has been demonstrated in the organic microrod(OMR).Noting that the RTP intensity of the as-prepared OMR is greatly enhanced when water is introduced,and the reason for the enhancement can be attributed to the formation of hydrogen-bonded networks inside the OMR.The hydrogen-bonded networks can confine the molecular motion effectively,leading to the stability of triplet states;thus the lifetime of the OMR can reach 1.64 s after introducing water.By virtue of the long lifetime of the OMR in the presence of water,multilevel data encryption based on the OMR has been demonstrated.展开更多
Piezochromic luminescent materials have shown great potential in advanced optoelectronic applications.However,most of luminescent materials usually undergo emission quenching under external stimuli.Herein,we demonstra...Piezochromic luminescent materials have shown great potential in advanced optoelectronic applications.However,most of luminescent materials usually undergo emission quenching under external stimuli.Herein,we demonstrate for the first time that the photoluminescence of carbon dots(CDs)confined within sodium hydroxide can be enhanced when high pressure is applied.They exhibit a 1.6-fold fluorescence enhancement compared with pristine CDs.Importantly,the enhanced fluorescence intensity can be retained after the release of pressure to ambient conditions.A combination of experimental analysis and theoretical simulations indicates that such an enhanced emission is mainly attributed to the strong confinement resulting from the sodium hydroxide matrix,which can separate the CDs spatially and restrict the nonradiative pathway.These results provide a rational strategy for manipulating the optical properties of CDs with enhanced and retainable photoluminescence(PL)performance,thus opening up a venue for designing luminescent CDs-based materials.展开更多
Phosphorescent carbon nanodots(CNDs)have various attractive properties and potential applications,but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods.Herein,a la...Phosphorescent carbon nanodots(CNDs)have various attractive properties and potential applications,but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods.Herein,a large-scale synthesis method for phosphorescent CNDs has been demonstrated via precursors’self-exothermic reaction at room temperature.The as-prepared CNDs show fluorescence and phosphorescence property,which are comparable with that synthesized by solvothermal and microwave method.Experimental and computational studies indicate that exotic atom doped sp^(2) hybridized carbon core works as an emissive center,which facilities the intersystem crossing from singlet state to triplet state.The CNDs show phosphorescence with tunable lifetimes from 193 ms to 1.13 s at different temperatures.The demonstration of large-scale synthesis of phosphorescent CNDs at room temperature opens up a new window for room temperature fabrication phosphorescent CNDs.展开更多
Energy transfer as an important component in light-harvesting antenna systems can mimic effectively natural photosynthesis processes,showing great potential in optoelectronic devices.Herein,we report a responsive poly...Energy transfer as an important component in light-harvesting antenna systems can mimic effectively natural photosynthesis processes,showing great potential in optoelectronic devices.Herein,we report a responsive polymeric hydrogel based on the combination of excited state intramolecular proton transfer(ESIPT) molecule(Salicylic acid,Sal) and terbium(Ⅲ)(Tb^(3+)),as enabled by external stimuli to construct artificial light-harvesting antenna systems.Benefiting from unique photophysical properties of Sal,the synthesized hydrogel displays a temperature-dependent reversible opaque?transparent states transition,accompanied with an interesting photoluminescence behavior.Moreover,by further incorporating europium(Ⅲ)(Eu^(3+)) into the hydrogel,we demonstrate well-defined cascades of energy transfer that provides a tunable optical output from the collection of lanthanides by the excitation of a common sensitizer(Sal) upon base vapor stimulation.Efficient energy transfer efficiency from Tb^(3+) to Eu^(3+),as high as 97.8%,was also obtained as established by the time-resolved fluorescence spectroscopy analysis.展开更多
Membrane associated guanylate kinases （MAGUKs） are a family of scaffold proteins that play essential roles in organ development, cell-cell communication, cell polarity establishment and maintenance, and cellular sig...Membrane associated guanylate kinases （MAGUKs） are a family of scaffold proteins that play essential roles in organ development, cell-cell communication, cell polarity establishment and maintenance, and cellular signal transduction. Every member of the MAGUK family contains a guanylate kinase-like （GK） domain, which has evolved from the enzyme catalyzing GMP to GDP conversion to become a protein-protein interaction module with no enzymatic activity. Mutations of MAGUKs are linked to a number of human diseases, including autism and hereditary deafness. In this review, we summarize the structural basis governing cellular function of various members of the MAGUKs. In particular, we focus on recent discoveries of MAGUK GKs as specific phospho-protein interaction modules, and discuss functional implications and connections to human diseases of such regulated MAGUK GK/target interactions.展开更多
基金founded by the Nationally Natural Science Foundation of China (41171159)the National Key Basic Research Program of China (2013CB956001)the Fundamental Research Funds for the Central Universities
文摘As the largest inland lake of China, along with its unique landscape and geographical location, Qinghai Lake has got much atten- tion of the scientists for a long time. The precursors have done substantive researches by using the lake sediment, which deepen our tmderstanding of the climate changes in this region. Although sand dunes and loess sediment are widely distributed around the lake, so far the researches on geochemical elements from aeolian sediment have been less reported. In this paper, we selected a typical aeolian profile on the east of Qinghai Lake. Based on systematic sampling and analysis of seven major geochemical ele- ments, combined with OSL dating and previous researches, this paper discusses climate changes in the Qinghai Lake area since 12.5 ka B.P.. Our conclusions are： （1） Before 12.5 ka B.P., the climate in this region was dry, cold, and accompanied by strong wind-sand activities. （2） During 12.5-11.9 ka B.P., the climate became warm and wet. However, there was an abrupt climate cooling event during 12.2-11.9 ka B.P., which likely corresponded to the Younger Dryas event. （3） During 11.9 8.0 ka B.P., the climate fluctuated greatly and frequently from warm to cold, and three cooling events occurred. （4） During 8.0-2.6 ka B.P., the climate was warm and humid. （5） Since 2.6 ka B.P., similar to the modem climate, the climate was mainly dry and cold.
基金the National Natural Science Foundation of China(Nos.31530010 and 21401168)the Special Project of Guangdong Province to Introduce Innovation and Entrepreneurship Team(No.2016ZT06N467)is acknowledged.
文摘Elemental state matter-heteroatom-doped carbon composites are of great importance for the development of anode in lithium ion batteries(LIBs).In this article,metal–organic frameworks(MOFs)are adopted as precursor to prepare Co composites via metallurgical pyrolysis under controllable conditions.The obtained nitrogen-doped porous carbon-Co nanocomposite possesses core–shell structure(Co@C–N).Co@C–N exhibits the best Li storage performances as anode active matter.After the 200th cycles at current density of 0.2 A g^(-1),a reversible capacity of 870 mAh g^(-1)is retained.A reversible capacity of 275 mAh g^(-1)still maintains with 5 A g^(-1).Co@C–N presents a high reversible capacity with excellent cycle stability.Considering the corresponding experimental and theoretical results,the Co0-based N-doped porous carbon composite is proposed to work as LIBs anode matter.These results provide a new design idea for electrode matters of metallic ion battery,and demonstrate that MOFs pyrolysis is an effective method for the construction of elemental state anode materials.
基金This work was supported by the National Natural Science Foundation of China(Nos.11904326,21601159,61604132,and 51602288)the National Science Fund for Distinguished Young Scholars(No.61425021)Key Science and Technology Project of Henan Province(No.171100210600).
文摘Room temperature phosphorescence(RTP)materials show potential applications in information security and optoelectronic devices,but it is still a challenge to achieve RTP in organic materials under water ambient due to the unstable property of triplet states.Herein,water-induced RTP has been demonstrated in the organic microrod(OMR).Noting that the RTP intensity of the as-prepared OMR is greatly enhanced when water is introduced,and the reason for the enhancement can be attributed to the formation of hydrogen-bonded networks inside the OMR.The hydrogen-bonded networks can confine the molecular motion effectively,leading to the stability of triplet states;thus the lifetime of the OMR can reach 1.64 s after introducing water.By virtue of the long lifetime of the OMR in the presence of water,multilevel data encryption based on the OMR has been demonstrated.
基金the National Natural Science Foundation of China(Nos.11804307,12074348,U2004168,62027816 and U1804155)the China Postdoctoral Science Foundation(Nos.2018M630830,2019T120631 and 2020M682310)the Natural Science Foundation of Henan Province(Nos.212300410410 and 212300410078).
文摘Piezochromic luminescent materials have shown great potential in advanced optoelectronic applications.However,most of luminescent materials usually undergo emission quenching under external stimuli.Herein,we demonstrate for the first time that the photoluminescence of carbon dots(CDs)confined within sodium hydroxide can be enhanced when high pressure is applied.They exhibit a 1.6-fold fluorescence enhancement compared with pristine CDs.Importantly,the enhanced fluorescence intensity can be retained after the release of pressure to ambient conditions.A combination of experimental analysis and theoretical simulations indicates that such an enhanced emission is mainly attributed to the strong confinement resulting from the sodium hydroxide matrix,which can separate the CDs spatially and restrict the nonradiative pathway.These results provide a rational strategy for manipulating the optical properties of CDs with enhanced and retainable photoluminescence(PL)performance,thus opening up a venue for designing luminescent CDs-based materials.
基金This work was supported by the National Natural Science Foundation of China(Nos.11904326,U1804155,and U1604263)China Postdoctoral Science Foundation(Nos.2019TQ0287,and 2019M662510)+1 种基金the Chemical Dynamics Research Center(No.21688102)the Key Technology Team of the Chinese Academy of Sciences(No.GJJSTD20190002).
文摘Phosphorescent carbon nanodots(CNDs)have various attractive properties and potential applications,but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods.Herein,a large-scale synthesis method for phosphorescent CNDs has been demonstrated via precursors’self-exothermic reaction at room temperature.The as-prepared CNDs show fluorescence and phosphorescence property,which are comparable with that synthesized by solvothermal and microwave method.Experimental and computational studies indicate that exotic atom doped sp^(2) hybridized carbon core works as an emissive center,which facilities the intersystem crossing from singlet state to triplet state.The CNDs show phosphorescence with tunable lifetimes from 193 ms to 1.13 s at different temperatures.The demonstration of large-scale synthesis of phosphorescent CNDs at room temperature opens up a new window for room temperature fabrication phosphorescent CNDs.
基金Project supported by the National Natural Science Foundation of China(21771050)the Natural Science Foundation of Hebei Province(B2018202134,B2016202149,B2016202147)Outstanding Innovative Topics of Hebei Province(220056)。
文摘Energy transfer as an important component in light-harvesting antenna systems can mimic effectively natural photosynthesis processes,showing great potential in optoelectronic devices.Herein,we report a responsive polymeric hydrogel based on the combination of excited state intramolecular proton transfer(ESIPT) molecule(Salicylic acid,Sal) and terbium(Ⅲ)(Tb^(3+)),as enabled by external stimuli to construct artificial light-harvesting antenna systems.Benefiting from unique photophysical properties of Sal,the synthesized hydrogel displays a temperature-dependent reversible opaque?transparent states transition,accompanied with an interesting photoluminescence behavior.Moreover,by further incorporating europium(Ⅲ)(Eu^(3+)) into the hydrogel,we demonstrate well-defined cascades of energy transfer that provides a tunable optical output from the collection of lanthanides by the excitation of a common sensitizer(Sal) upon base vapor stimulation.Efficient energy transfer efficiency from Tb^(3+) to Eu^(3+),as high as 97.8%,was also obtained as established by the time-resolved fluorescence spectroscopy analysis.
文摘Membrane associated guanylate kinases （MAGUKs） are a family of scaffold proteins that play essential roles in organ development, cell-cell communication, cell polarity establishment and maintenance, and cellular signal transduction. Every member of the MAGUK family contains a guanylate kinase-like （GK） domain, which has evolved from the enzyme catalyzing GMP to GDP conversion to become a protein-protein interaction module with no enzymatic activity. Mutations of MAGUKs are linked to a number of human diseases, including autism and hereditary deafness. In this review, we summarize the structural basis governing cellular function of various members of the MAGUKs. In particular, we focus on recent discoveries of MAGUK GKs as specific phospho-protein interaction modules, and discuss functional implications and connections to human diseases of such regulated MAGUK GK/target interactions.
