Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior micr...Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior microstructure,as well as good compatibility with other electromagnetic(EM)components.Herein,we realized the decoration of rGO aerogel with Mo_(2)C nanoparticles by sequential hydrothermal assembly,freeze-drying,and high-temperature pyrolysis.Results show that Mo_(2)C nanoparticle loading can be easily controlled by the ammonium molybdate to glucose molar ratio.The hydrophobicity and thermal insulation of the rGO aerogel are effectively improved upon the introduction of Mo_(2)C nanoparticles,and more importantly,these nanoparticles regulate the EM properties of the rGO aerogel to a large extent.Although more Mo_(2)C nanoparticles may decrease the overall attenuation ability of the rGO aerogel,they bring much better impedance matching.At a molar ratio of 1:1,a desirable balance between attenuation ability and impedance matching is observed.In this context,the Mo_(2)C/r GO aerogel displays strong reflection loss and broad response bandwidth,even with a small applied thickness(1.7 mm)and low filler loading(9.0wt%).The positive effects of Mo_(2)C nanoparticles on multifunctional properties may render Mo_(2)C/r GO aerogels promising candidates for high-performance EWAMs under harsh conditions.展开更多
Objective:To observe the clinical efficacy of dapagliflozin in the treatment of type 2 diabetes mellitus(T2DM)complicated with heart failure with mildly reduced ejection fraction(HFmrEF,40%≤LVEF<50%).Methods:A tot...Objective:To observe the clinical efficacy of dapagliflozin in the treatment of type 2 diabetes mellitus(T2DM)complicated with heart failure with mildly reduced ejection fraction(HFmrEF,40%≤LVEF<50%).Methods:A total of 84 patients with T2DM complicated with HFmrEF hospitalized in our hospital from October 2019 to October 2021 were selected,and random number table method was used to divide into the control group and the study group each 42 cases.Both groups used basal hypoglycemic and standardized anti-heart failure therapy,and the study group was treated with dapagliflozin simultaneously.Nine months later,the following indexes were compared between the two groups before and after treatment:the cardiac function indicators:N-terminal pro brain natriuretic peptide(NT-proBNP),left ventricular ejection fraction(LVEF);exercise endurance:6-minute walk distance(6MWD),NYHA cardiac function class,the score of the Minnesota living with heart failure questionnaire(MLHFQ)and the incidence of major adverse cardiovascular events(MACE).Results:Nine months later,the two groups showed decreased NT-proBNP level,increased LVEF,prolonged 6MWD,improved NYHA cardiac function grade,decreased MLHFQ score,and statistically significant differences within both groups compared with before treatment(P<0.05),after treatment significant differences were displayed between the two groups(P<0.05).Less patients had MACE events and adverse drug reactions in the study group compared with the control group.Conclusion:Dapagliflozin in the treatment of T2DM patients with HFmrEF can improve cardiac function indicators,improve exercise endurance,improve NYHA cardiac function class,improve patient's quality of life,and reduce the incidence of MACE events,with no obvious side effects.展开更多
Iron disulfide is considered to be a potential anode material for sodium-ion batteries due to its high theoretical capacity. However, its applications are seriously limited by the weak conductivity and large volume ch...Iron disulfide is considered to be a potential anode material for sodium-ion batteries due to its high theoretical capacity. However, its applications are seriously limited by the weak conductivity and large volume change, which results in low reversible capacity and poor cycling stability.Herein, reduced graphene oxide-wrapped FeS_2(FeS_2/rGO)composite was fabricated to achieve excellent electrochemical performance via a facile two-step method. The introduction of rGO effectively improved the conductivity,BET surface area, and structural stability of the FeS_2 active material, thus endowing it with high specific capacity, good rate capability, as well as excellent cycling stability. Electrochemical measurements show that the FeS_2/rGO composite had a high initial discharge capacity of 1263.2 mAh gg^(-1) at 100 mA gg^(-1) and a high discharge capacity of 344 mAh gg^(-1) at 10 A gg^(-1), demonstrating superior rate performance. After 100 cycles at 100 mA gg^(-1),the discharge capacity remained at 609.5 mAh g^(-1), indicating the excellent cycling stability of the FeS_2/rGO electrode.展开更多
The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed a...The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few-layer graphene sheets loaded with ultrafine SnO_(2)nanocrystals,using short exposure of microwave to xerogel of graphene oxide(GO)and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO(RGO).The resultant nanocomposites(SnO_(2)@MWG)enabled significantly quickened redox processes as SIB anode,which led to remarkable full anode-specific capacity reaching 538 mAh g^(−1)at 0.05 A g^(−1)(about 1.45 times of the theoretical capacity of graphite for the LIB),in addition to outstanding rate performance over prolonged charge–discharge cycling.Anodes based on the optimized SnO_(2)@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g^(−1),and capacity retention of over 70.4%was maintained at a high areal loading of 3.4 mg cm^(−2),highly desirable for high energy density SIBs to rival the current benchmark LIBs.展开更多
As one of prussian blue analogues,Co_(3)[Co(CN)_(6)]_(2) has been explored as a promising anode material for potassium-ion batteries(PIBs) owing to its high potassium storage capacity.Unfortunately,Co_(3)[Co(CN)_(6)]_...As one of prussian blue analogues,Co_(3)[Co(CN)_(6)]_(2) has been explored as a promising anode material for potassium-ion batteries(PIBs) owing to its high potassium storage capacity.Unfortunately,Co_(3)[Co(CN)_(6)]_(2) possesses low electronic conductivity and its structure collapses easily during potassiation and depotassiation,resulting in poor rate performance and cyclic stability.To solve these problems,we develop a facile multi-step method to successfully combine uniformCo_(3)[Co(CN)_(6)]_(2) nanocubes with rGO by C-O-Co bonds.As expected,these chemcial bonds shorten the distance betweenCo_(3)[Co(CN)_(6)]_(2) and rGO to the angstrom meter level,which significantly improve the electronic conductivity ofCo_(3)[Co(CN)_(6)]_(2).Besides,the complete encapsulation ofCo_(3)[Co(CN)_(6)]_(2) nanocubes by rGO endows the structure ofCo_(3)[Co(CN)_(6)]_(2) with high stability,thus withstanding repeated insertion/extraction of potassium-ions without visible morphological and structural changes.Benefiting from the abovementioned structural advantages,the CO3 [Co(CN)6]2/rGO nanocomposite exhibits a high reversible capacity of 400.8 mAh g^(-1) at a current density of 0.1 A g^(-1),an exceptional rate capability of 115.5 mAh g^(-1) at 5 A g^(-1), and an ultralong cycle life of 231.9 mAh g^(-1) at 0.1 A g^(-1) after 1000 cycles.Additionally,the effects of different amounts of rGO and different sizes ofCo_(3)[Co(CN)_(6)]_(2) nanocubes on the potassium storage performance are also studied.This work offers an ideal route to significantly enhance the electrochemical properties of prussian blue analogues.展开更多
In this work, an efficient photocatalytic material was prepared directly on Indium tin oxide (ITO) glass substrates by fabricating Cu2S and graphene oxide onto graphene for photoelectrochemical (PEC) water splitting. ...In this work, an efficient photocatalytic material was prepared directly on Indium tin oxide (ITO) glass substrates by fabricating Cu2S and graphene oxide onto graphene for photoelectrochemical (PEC) water splitting. The double laminated reduced graphene/Cu2S/reduced graphene/graphene oxide (RG/Cu2S/RG/GO) nanofilms were characterized, and an enhanced photoelectrochemical response in the visible region was discovered. The photocurrent density of the nanofilms for PEC water splitting was measured to be up to 1.98 mA/cm(2), which could be ascribed to the followings: (i) a higher efficiency of light-harvesting because of GO coupling with Cu2S that could broaden the absorbing solar spectrum and enhance the light utilization efficiency; (ii) a stepwise structure of band-edge levels in the Cu2S/GO electrode was constructed; (iii) double laminated electron accelerator (RG) was used in the Cu2S/GO materials to get better electron-injecting efficiency. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
Cu2O@Cu nanocomposite was prepared by a simple high temperature calcination reaction in N2 atmosphere.The as-prepared samples were characterized by XRD,SEM and TEM,which indicated that the product formed by nano-sheet...Cu2O@Cu nanocomposite was prepared by a simple high temperature calcination reaction in N2 atmosphere.The as-prepared samples were characterized by XRD,SEM and TEM,which indicated that the product formed by nano-sheets stacking had a high specific surface area.The as-synthesized material shows efficient catalytic activity for the reduction of organic compound in aqueous medium,in which 4-nitrophenol can be reduced to p-aminophenol and Congo red can be degraded to colorless solution.展开更多
The two Co sites are well characterized in reduced Co-Mo/Al_2O_3 and Ru-Co- Mo/Al_2O_3 by new bands at 1895 and 1880 cm^(-1)in the IR spectra due to NO adsorption.
In this paper a singularly perturbed linear second order hyperbolic problem with zeroth order reduced equation is discussed. Firstly, an energy inequality of the solution and an estimate of the remainder term of the a...In this paper a singularly perturbed linear second order hyperbolic problem with zeroth order reduced equation is discussed. Firstly, an energy inequality of the solution and an estimate of the remainder term of the asymptotic solution are given. Then an exponentially fitted difference scheme is developed in an equidistant mesh. Finally, uniform convergence in small parameter is proved in the sense of discrete energy norm.展开更多
基金supported by the China Postdoctoral Science Foundation(No.2021MD703944)the Fund of Science and Technology on Near-Surface Detection Laboratory(No.6142414211808)+1 种基金the Director Fund of State Key Laboratory of Pulsed Power Laser Technology(No.SKL2021ZR06)the National Natural Science Foundation of China(No.21776053)。
文摘Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior microstructure,as well as good compatibility with other electromagnetic(EM)components.Herein,we realized the decoration of rGO aerogel with Mo_(2)C nanoparticles by sequential hydrothermal assembly,freeze-drying,and high-temperature pyrolysis.Results show that Mo_(2)C nanoparticle loading can be easily controlled by the ammonium molybdate to glucose molar ratio.The hydrophobicity and thermal insulation of the rGO aerogel are effectively improved upon the introduction of Mo_(2)C nanoparticles,and more importantly,these nanoparticles regulate the EM properties of the rGO aerogel to a large extent.Although more Mo_(2)C nanoparticles may decrease the overall attenuation ability of the rGO aerogel,they bring much better impedance matching.At a molar ratio of 1:1,a desirable balance between attenuation ability and impedance matching is observed.In this context,the Mo_(2)C/r GO aerogel displays strong reflection loss and broad response bandwidth,even with a small applied thickness(1.7 mm)and low filler loading(9.0wt%).The positive effects of Mo_(2)C nanoparticles on multifunctional properties may render Mo_(2)C/r GO aerogels promising candidates for high-performance EWAMs under harsh conditions.
基金Suqian Science and Technology Plan Project(No.Z2019178)。
文摘Objective:To observe the clinical efficacy of dapagliflozin in the treatment of type 2 diabetes mellitus(T2DM)complicated with heart failure with mildly reduced ejection fraction(HFmrEF,40%≤LVEF<50%).Methods:A total of 84 patients with T2DM complicated with HFmrEF hospitalized in our hospital from October 2019 to October 2021 were selected,and random number table method was used to divide into the control group and the study group each 42 cases.Both groups used basal hypoglycemic and standardized anti-heart failure therapy,and the study group was treated with dapagliflozin simultaneously.Nine months later,the following indexes were compared between the two groups before and after treatment:the cardiac function indicators:N-terminal pro brain natriuretic peptide(NT-proBNP),left ventricular ejection fraction(LVEF);exercise endurance:6-minute walk distance(6MWD),NYHA cardiac function class,the score of the Minnesota living with heart failure questionnaire(MLHFQ)and the incidence of major adverse cardiovascular events(MACE).Results:Nine months later,the two groups showed decreased NT-proBNP level,increased LVEF,prolonged 6MWD,improved NYHA cardiac function grade,decreased MLHFQ score,and statistically significant differences within both groups compared with before treatment(P<0.05),after treatment significant differences were displayed between the two groups(P<0.05).Less patients had MACE events and adverse drug reactions in the study group compared with the control group.Conclusion:Dapagliflozin in the treatment of T2DM patients with HFmrEF can improve cardiac function indicators,improve exercise endurance,improve NYHA cardiac function class,improve patient's quality of life,and reduce the incidence of MACE events,with no obvious side effects.
基金supported by National Natural Science Foundation of China (51702138, 51702079)Natural Science Foundation of Jiangsu Province (BK20160213)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Iron disulfide is considered to be a potential anode material for sodium-ion batteries due to its high theoretical capacity. However, its applications are seriously limited by the weak conductivity and large volume change, which results in low reversible capacity and poor cycling stability.Herein, reduced graphene oxide-wrapped FeS_2(FeS_2/rGO)composite was fabricated to achieve excellent electrochemical performance via a facile two-step method. The introduction of rGO effectively improved the conductivity,BET surface area, and structural stability of the FeS_2 active material, thus endowing it with high specific capacity, good rate capability, as well as excellent cycling stability. Electrochemical measurements show that the FeS_2/rGO composite had a high initial discharge capacity of 1263.2 mAh gg^(-1) at 100 mA gg^(-1) and a high discharge capacity of 344 mAh gg^(-1) at 10 A gg^(-1), demonstrating superior rate performance. After 100 cycles at 100 mA gg^(-1),the discharge capacity remained at 609.5 mAh g^(-1), indicating the excellent cycling stability of the FeS_2/rGO electrode.
基金funded by the Zhengzhou Materials Genome Institute,the National Talents Program of China,and Key Innovation Projects of the Zhengzhou Municipal City of China.
文摘The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few-layer graphene sheets loaded with ultrafine SnO_(2)nanocrystals,using short exposure of microwave to xerogel of graphene oxide(GO)and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO(RGO).The resultant nanocomposites(SnO_(2)@MWG)enabled significantly quickened redox processes as SIB anode,which led to remarkable full anode-specific capacity reaching 538 mAh g^(−1)at 0.05 A g^(−1)(about 1.45 times of the theoretical capacity of graphite for the LIB),in addition to outstanding rate performance over prolonged charge–discharge cycling.Anodes based on the optimized SnO_(2)@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g^(−1),and capacity retention of over 70.4%was maintained at a high areal loading of 3.4 mg cm^(−2),highly desirable for high energy density SIBs to rival the current benchmark LIBs.
基金supported by the National Natural Science Foundation of China(51577094)the Natural Science Foundation of Jiangsu Province of China(BK20180086)。
文摘As one of prussian blue analogues,Co_(3)[Co(CN)_(6)]_(2) has been explored as a promising anode material for potassium-ion batteries(PIBs) owing to its high potassium storage capacity.Unfortunately,Co_(3)[Co(CN)_(6)]_(2) possesses low electronic conductivity and its structure collapses easily during potassiation and depotassiation,resulting in poor rate performance and cyclic stability.To solve these problems,we develop a facile multi-step method to successfully combine uniformCo_(3)[Co(CN)_(6)]_(2) nanocubes with rGO by C-O-Co bonds.As expected,these chemcial bonds shorten the distance betweenCo_(3)[Co(CN)_(6)]_(2) and rGO to the angstrom meter level,which significantly improve the electronic conductivity ofCo_(3)[Co(CN)_(6)]_(2).Besides,the complete encapsulation ofCo_(3)[Co(CN)_(6)]_(2) nanocubes by rGO endows the structure ofCo_(3)[Co(CN)_(6)]_(2) with high stability,thus withstanding repeated insertion/extraction of potassium-ions without visible morphological and structural changes.Benefiting from the abovementioned structural advantages,the CO3 [Co(CN)6]2/rGO nanocomposite exhibits a high reversible capacity of 400.8 mAh g^(-1) at a current density of 0.1 A g^(-1),an exceptional rate capability of 115.5 mAh g^(-1) at 5 A g^(-1), and an ultralong cycle life of 231.9 mAh g^(-1) at 0.1 A g^(-1) after 1000 cycles.Additionally,the effects of different amounts of rGO and different sizes ofCo_(3)[Co(CN)_(6)]_(2) nanocubes on the potassium storage performance are also studied.This work offers an ideal route to significantly enhance the electrochemical properties of prussian blue analogues.
基金the financial support from China Postdoctoral Science Foundation(2014M551023)
文摘In this work, an efficient photocatalytic material was prepared directly on Indium tin oxide (ITO) glass substrates by fabricating Cu2S and graphene oxide onto graphene for photoelectrochemical (PEC) water splitting. The double laminated reduced graphene/Cu2S/reduced graphene/graphene oxide (RG/Cu2S/RG/GO) nanofilms were characterized, and an enhanced photoelectrochemical response in the visible region was discovered. The photocurrent density of the nanofilms for PEC water splitting was measured to be up to 1.98 mA/cm(2), which could be ascribed to the followings: (i) a higher efficiency of light-harvesting because of GO coupling with Cu2S that could broaden the absorbing solar spectrum and enhance the light utilization efficiency; (ii) a stepwise structure of band-edge levels in the Cu2S/GO electrode was constructed; (iii) double laminated electron accelerator (RG) was used in the Cu2S/GO materials to get better electron-injecting efficiency. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金Supported by the Natural Science Foundation of Fujian Province(No.2017J01420)Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry(FJKL_FBCM201803)
文摘Cu2O@Cu nanocomposite was prepared by a simple high temperature calcination reaction in N2 atmosphere.The as-prepared samples were characterized by XRD,SEM and TEM,which indicated that the product formed by nano-sheets stacking had a high specific surface area.The as-synthesized material shows efficient catalytic activity for the reduction of organic compound in aqueous medium,in which 4-nitrophenol can be reduced to p-aminophenol and Congo red can be degraded to colorless solution.
文摘The two Co sites are well characterized in reduced Co-Mo/Al_2O_3 and Ru-Co- Mo/Al_2O_3 by new bands at 1895 and 1880 cm^(-1)in the IR spectra due to NO adsorption.
文摘In this paper a singularly perturbed linear second order hyperbolic problem with zeroth order reduced equation is discussed. Firstly, an energy inequality of the solution and an estimate of the remainder term of the asymptotic solution are given. Then an exponentially fitted difference scheme is developed in an equidistant mesh. Finally, uniform convergence in small parameter is proved in the sense of discrete energy norm.
