The catalytic properties of a series of cobalt complexes containing bidenated nitrogen ligand for displacement reaction of trialkylaluminum with ethylene is reported. Effect of different reaction time, temperature an...The catalytic properties of a series of cobalt complexes containing bidenated nitrogen ligand for displacement reaction of trialkylaluminum with ethylene is reported. Effect of different reaction time, temperature and cobalt complexes containing different ligand on catalyst performance has been investigated.展开更多
DNAzyme amplifiers have been extensively explored as a useful sensing platform,but single DNAzyme amplifier is limited in biosensing applications by its low sensitivity.Herein,a cascade DNAzyme amplifier was designed ...DNAzyme amplifiers have been extensively explored as a useful sensing platform,but single DNAzyme amplifier is limited in biosensing applications by its low sensitivity.Herein,a cascade DNAzyme amplifier was designed by exploiting concurrent amplification cycle principles of toehold-mediated strand displacement reaction(TSDR)and Zn^(2+)-assisted DNAzyme cycle with lower cost and simpler procedures.Compared with single DNAzyme amplifier,the proposed TSDR-propelled cascade DNAzyme amplifier exhibited higher sensitivity by releasing more DNAzyme through TSDR to cleave substrate strand during the DNAzyme cycle.Base on this,let-7a could be sensitively detected in the range of 5-50 nmol/L with a detection limit of 64 pmol/L.Furthermore,the dual signal amplification strategy of the cascade DNAzyme amplifier exhibited excellent selectivity to distinguish single-base mismatched DNA strands,which has been successfully applied to the determination of let-7a in blood serum,showing high promise in early cancer diagnosis.展开更多
An A1203p/A1 composite was successfully synthesized using a displacement reaction between 80 wt% A1 and 20 wt% CuO powders at a heating rate of 5 ℃/min. Two different sizes CuO particles were used, and all the experi...An A1203p/A1 composite was successfully synthesized using a displacement reaction between 80 wt% A1 and 20 wt% CuO powders at a heating rate of 5 ℃/min. Two different sizes CuO particles were used, and all the experiments were conducted under an argon atmosphere. To analyze the microstructural evolution during synthesis, the A1-20 wt% CuO samples were heated to the temperatures selected according to the differential scanning calorimetry curve and then immediately quenched with water. The phase composites and microstructure of the water-quenching samples were in- vestigated using X-ray diffraction, optical microscopy, scanning electron microscopy and energy-dispersive spectrometry. The results indicate that the CuO particle size has a significant effect on the microstructural evolution of the samples during the heating stage and on the microstructure of synthesized composites. Smaller CuO particles can decrease the reaction temperature, narrow the reaction temperature range at the different reaction stages during the heating stage and make the size and distribution of in situ A1203 particles more uniform. The reaction between A1 and CuO can be complete as the temperature rises to 900 ℃. The size of the in situ A1203 particles is approximately 5 μm when the size of the CuO particles is less than 6 μm. This sample has a relatively high Rockwell hardness of 60 HRB.展开更多
The reactions of 1,3-dinitro-2-chloro-5-trifluorotoluene(DNCTT)(1)and its bridged com- pounds with bidentate nucleophiles have been investigated.Primary or secondary diamines and diethylene glycol react with 1 and its...The reactions of 1,3-dinitro-2-chloro-5-trifluorotoluene(DNCTT)(1)and its bridged com- pounds with bidentate nucleophiles have been investigated.Primary or secondary diamines and diethylene glycol react with 1 and its bridged derivatives by replacing the substituent grouppara to CF_3, whereas ethanedithiol reacts either by replacing the substituent group para to CF_3 or by displacing both groups and a nitro group.The results have been rationalized in terms of electronic effects and nucleophilicity of the nucleophiles.展开更多
Rechargeable Mg batteries potentially display lower cost and competitive energy density compared with their Li-ion counterparts.However,the practical implementation of high area-capacity cathodes still remains a formi...Rechargeable Mg batteries potentially display lower cost and competitive energy density compared with their Li-ion counterparts.However,the practical implementation of high area-capacity cathodes still remains a formidably challenging task.This work presents the sulfur/copper integrated cathodes fabricated by the conventional blade-coating process and slurry-dipping method.The sulfur/copper foil integrated cathodes deliver a high area-capacity of 2.6 mAh cm^(-2)after 40 cycles,while the sulfur/copperfoam integrated cathode exhibits an ultrahigh area-capacity of 35.4 mAh cm^(-2),corresponding to 743.1 Wh L^(-1)at the electrode level(1.5 times higher than the LiCoO_(2)-graphite system).The in-situ formed copper sulfide intermediates with sufficient cation defects can act as functional intermediates to regulate the sulfur electrochemistry during the first discharge process.The subsequent cycles are operated by the reversible displacement reaction between Mg-ions and copper sulfide active substances.In particular,the copper ions prefer to extrude along the[001]direction in copper sulfides lattice and simultaneously the rock-salt MgS crystals are generated.Besides,the nonuniform surface topography of the cycled Mgmetal anode,caused by the spatial inhomogeneity in current distribution,is demonstrated to lead to the battery performance degradation for high area-capacity Mg batteries.展开更多
We describe here a target recycling transcription of lighting-up aptamer strategy for detecting ATP in human serums in a label-free means with high sensitivity.ATP molecules specifically recognize the binding aptamer ...We describe here a target recycling transcription of lighting-up aptamer strategy for detecting ATP in human serums in a label-free means with high sensitivity.ATP molecules specifically recognize the binding aptamer and result in the structure switching of the DNA assembly probes to imitate the target ATP molecule recycling cycles through the toehold-mediated strand displacement reaction,which causes the formation of many dsDNAs containing the RNA promoter sequences for subsequent transcription generation of large amounts of lighting-up aptamers.The organic dye,malachite green,then associates with these lighting-up aptamers to produce significantly enhanced fluorescence signals,which can sensitively detect ATP within a dynamic range from 10 to 500 nM in a label-free way.The sensing approach shows a detection limit of 7.3 nM and also has an excellent selectivity for ATP analogue molecules.In addition,this method can detect ATP molecules in diluted human serum samples sensitively,which proves the promising potential to diagnose ATP-related diseases.展开更多
文摘The catalytic properties of a series of cobalt complexes containing bidenated nitrogen ligand for displacement reaction of trialkylaluminum with ethylene is reported. Effect of different reaction time, temperature and cobalt complexes containing different ligand on catalyst performance has been investigated.
基金financially supported by the National Natural Science Foundation of China(NSFC,Nos.22074124 and 22134005)the fund of Fundamental Research Funds for the Central Universities(No.XDJK2020TY001)+1 种基金Chongqing Talents Program for Outstanding Scientists(No.cstc2021ycjh-bgzxm0178)the Chongqing Graduate Student Scientific Research Innovation Project(No.CYB21119)。
文摘DNAzyme amplifiers have been extensively explored as a useful sensing platform,but single DNAzyme amplifier is limited in biosensing applications by its low sensitivity.Herein,a cascade DNAzyme amplifier was designed by exploiting concurrent amplification cycle principles of toehold-mediated strand displacement reaction(TSDR)and Zn^(2+)-assisted DNAzyme cycle with lower cost and simpler procedures.Compared with single DNAzyme amplifier,the proposed TSDR-propelled cascade DNAzyme amplifier exhibited higher sensitivity by releasing more DNAzyme through TSDR to cleave substrate strand during the DNAzyme cycle.Base on this,let-7a could be sensitively detected in the range of 5-50 nmol/L with a detection limit of 64 pmol/L.Furthermore,the dual signal amplification strategy of the cascade DNAzyme amplifier exhibited excellent selectivity to distinguish single-base mismatched DNA strands,which has been successfully applied to the determination of let-7a in blood serum,showing high promise in early cancer diagnosis.
基金financially supported by the Inner Mongolia Natural Science Foundation of China (Nos. 2012MS0801 and 2013MS0804)
文摘An A1203p/A1 composite was successfully synthesized using a displacement reaction between 80 wt% A1 and 20 wt% CuO powders at a heating rate of 5 ℃/min. Two different sizes CuO particles were used, and all the experiments were conducted under an argon atmosphere. To analyze the microstructural evolution during synthesis, the A1-20 wt% CuO samples were heated to the temperatures selected according to the differential scanning calorimetry curve and then immediately quenched with water. The phase composites and microstructure of the water-quenching samples were in- vestigated using X-ray diffraction, optical microscopy, scanning electron microscopy and energy-dispersive spectrometry. The results indicate that the CuO particle size has a significant effect on the microstructural evolution of the samples during the heating stage and on the microstructure of synthesized composites. Smaller CuO particles can decrease the reaction temperature, narrow the reaction temperature range at the different reaction stages during the heating stage and make the size and distribution of in situ A1203 particles more uniform. The reaction between A1 and CuO can be complete as the temperature rises to 900 ℃. The size of the in situ A1203 particles is approximately 5 μm when the size of the CuO particles is less than 6 μm. This sample has a relatively high Rockwell hardness of 60 HRB.
文摘The reactions of 1,3-dinitro-2-chloro-5-trifluorotoluene(DNCTT)(1)and its bridged com- pounds with bidentate nucleophiles have been investigated.Primary or secondary diamines and diethylene glycol react with 1 and its bridged derivatives by replacing the substituent grouppara to CF_3, whereas ethanedithiol reacts either by replacing the substituent group para to CF_3 or by displacing both groups and a nitro group.The results have been rationalized in terms of electronic effects and nucleophilicity of the nucleophiles.
基金supported by the National Natural Science Foundation of China(21805157,51972187)the Project funded by China Postdoctoral Science Foundation(2021M701817)+2 种基金the Natural Science Foundation of Shandong Provincial(ZR2021QE166)the National Natural Science Foundation for Distinguished Young Scholars of China(51625204)the Major Basic Research Program of Natural Science Foundation of Shandong Province(ZR2020ZD09)。
文摘Rechargeable Mg batteries potentially display lower cost and competitive energy density compared with their Li-ion counterparts.However,the practical implementation of high area-capacity cathodes still remains a formidably challenging task.This work presents the sulfur/copper integrated cathodes fabricated by the conventional blade-coating process and slurry-dipping method.The sulfur/copper foil integrated cathodes deliver a high area-capacity of 2.6 mAh cm^(-2)after 40 cycles,while the sulfur/copperfoam integrated cathode exhibits an ultrahigh area-capacity of 35.4 mAh cm^(-2),corresponding to 743.1 Wh L^(-1)at the electrode level(1.5 times higher than the LiCoO_(2)-graphite system).The in-situ formed copper sulfide intermediates with sufficient cation defects can act as functional intermediates to regulate the sulfur electrochemistry during the first discharge process.The subsequent cycles are operated by the reversible displacement reaction between Mg-ions and copper sulfide active substances.In particular,the copper ions prefer to extrude along the[001]direction in copper sulfides lattice and simultaneously the rock-salt MgS crystals are generated.Besides,the nonuniform surface topography of the cycled Mgmetal anode,caused by the spatial inhomogeneity in current distribution,is demonstrated to lead to the battery performance degradation for high area-capacity Mg batteries.
基金supported by the Science and Technology Cooperation Project between Chinese and Australian Governments (2017YFE0132300)the National Natural Science Foundation of China (NSFC 51929201, 51672268, 51720105015, 51972138, 51872263, and 51828202)+1 种基金the Science and Technology Development Planning Project of Jilin Province (20190201232JC)the CASCroucher Funding Scheme for Joint Laboratories (CAS18204)
基金supported by National Natural Science Foundation of China(22004010)the Chongqing Science and Technology Commission of China(cstc2019jcyj-msxmX0196)+1 种基金the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN201901135)the Scientific Research Foundation of Chongqing University of Technology(W.Zhou)
文摘We describe here a target recycling transcription of lighting-up aptamer strategy for detecting ATP in human serums in a label-free means with high sensitivity.ATP molecules specifically recognize the binding aptamer and result in the structure switching of the DNA assembly probes to imitate the target ATP molecule recycling cycles through the toehold-mediated strand displacement reaction,which causes the formation of many dsDNAs containing the RNA promoter sequences for subsequent transcription generation of large amounts of lighting-up aptamers.The organic dye,malachite green,then associates with these lighting-up aptamers to produce significantly enhanced fluorescence signals,which can sensitively detect ATP within a dynamic range from 10 to 500 nM in a label-free way.The sensing approach shows a detection limit of 7.3 nM and also has an excellent selectivity for ATP analogue molecules.In addition,this method can detect ATP molecules in diluted human serum samples sensitively,which proves the promising potential to diagnose ATP-related diseases.