基于CoSE(cloud of secure elements)概念,提出一个NFC安全支付协议。根据CoSE架构部署一个可信云支付平台,使用虚拟SE替代硬件安全模块,所有交易项都由云支付平台完成;商户的POS终端充当消费者和云支付平台的通信桥梁,消费者的NFC设备...基于CoSE(cloud of secure elements)概念,提出一个NFC安全支付协议。根据CoSE架构部署一个可信云支付平台,使用虚拟SE替代硬件安全模块,所有交易项都由云支付平台完成;商户的POS终端充当消费者和云支付平台的通信桥梁,消费者的NFC设备和商户的POS终端通过射频场连接,消费者NFC设备不需要数据网络即可完成支付流程;交易过程中通过对交易双方身份信息与随机数进行hash运算,实现正常交易匿名性。通过安全性分析及实验验证了该协议的正确性和安全性。展开更多
In this study, we investigated the effects of adenovirus-mediated transfection of PC12 cells with glucose transporter 3 after ischemic injury. The results of flow cytometry and TUNEL showed that exogenous glucose tran...In this study, we investigated the effects of adenovirus-mediated transfection of PC12 cells with glucose transporter 3 after ischemic injury. The results of flow cytometry and TUNEL showed that exogenous glucose transporter 3 significantly suppressed PC12 cell apoptosis induced by ischemic injury. The results of isotopic scintiscan and western blot assays showed that, the glucose uptake rate was significantly increased and nuclear factor kappaB expression was significantly decreased after adenovirus-mediated transfection of ischemic PC12 cells with glucose transporter 3. These results suggest that adenovirus-mediated transfection of cells with glucose transporter 3 elevates the energy metabolism of PC12 cells with ischemic injury, and inhibits cell apoptosis.展开更多
The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type materials.Herein,we design a current collector-integrated electrode(N-CoSe/Co...The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type materials.Herein,we design a current collector-integrated electrode(N-CoSe/CoSe_(2)-C@Cu) as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe_(2) heterojunction with rich Se vacancy defects,conductive sp^2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural stability.Consequently,the well-designed N-CoSe/CoSe_(2)-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g^(-1) at 0.1 A·g^(-1) after 200cycles),an exceptional rate capability(223.5 mAh·g^(-1) at2000 mA·g^(-1)),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g^(-1)).Impressively,ex situ scanning electron microscopy(SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe_(2)-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.展开更多
One-dimensional nano-structured materials have attracted attention due to its unique properties afforded such as the across-linked structures and large aspect ratios.In this work,one-dimensional CoSe@N-doped carbon na...One-dimensional nano-structured materials have attracted attention due to its unique properties afforded such as the across-linked structures and large aspect ratios.In this work,one-dimensional CoSe@N-doped carbon nanofibers(CoSe@NCNFs)are successfully by combining the techniques of electrospinning and annealing.Selenium powder are directly dispersed in the polyacrylonitrile/N,N-Dimethylformamide(DMF)solution containing cobalt salt to form the product.The performance of these materials was investigated in Li-ion batteries after the annealing at different temperatures.The Co Se@NC nanofibers annealed at 550℃(CoSe@NC-550)and displayed excellent storage properties,affording a high capacity of 796 m Ah·g-1at a current density of 1 A·g^-1 for 100 cycles.Moreover,it is confirmed that the pseudocapacitive contribution of CoSe@NC-550 is up to 72.8%at the scan rate of 1 mV/s through the cyclic voltammetry analysis.展开更多
Recently,abundant resources,low-cost sodium-ion batteries are deemed to the new-generation battery in the field of largescale energy storage.Nevertheless,poor active reaction dynamics,dissolution of intermediates and ...Recently,abundant resources,low-cost sodium-ion batteries are deemed to the new-generation battery in the field of largescale energy storage.Nevertheless,poor active reaction dynamics,dissolution of intermediates and electrolyte matching problems are significant challenges that need to be solved.Herein,dimensional gradient structure of sheet-tube-dots is constructed with CoSe2@CNTs-MXene.Gradient structure is conducive to fast migration of electrons and ions with the association of ether electrolyte.For half-cell,CoSe2@CNTs-MXene exhibits high initial coulomb efficiency(81.7%)and excellent cycling performance(400 mAh g^-1 cycling for 200 times in 2 Ag^−1).Phase transformation pathway from crystalline CoSe2-Na2Se with Co and then amorphous CoSe2 in the discharge/charge process is also explored by in situ X-ray diffraction.Density functional theory study discloses the CoSe2@CNTs-MXene in ether electrolyte system which contributes to stable sodium storage performance owing to the strong adsorption force from hierarchical structure and weak interaction between electrolyte and electrode interface.For full cell,CoSe2@CNTs-MXene//Na3V2(PO4)3/C full battery can also afford a competitively reversible capacity of 280 mAh g^−1 over 50 cycles.Concisely,profiting from dimensional gradient structure and matched electrolyte of CoSe2@CNTs-MXene hold great application potential for stable sodium storage.展开更多
The high cost and low reserves of noble metals greatly hinder their practical applications in new energy production and conversion.The exploration of cost-effective alternative electrocatalysts with the ability to dri...The high cost and low reserves of noble metals greatly hinder their practical applications in new energy production and conversion.The exploration of cost-effective alternative electrocatalysts with the ability to drive hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is extremely significant to promote overall water splitting.Herein,ultrathin CoSe2/CNTs nanocomposites have been synthesized by a facile two-step method,where the ultrathin Co-MOF(metal organic-framework)decorated with cable-like carbon nanotubes(CNTs)(Co-MOF/CNTs)was initially fabricated,and followed a lowtemperature selenization process.The ultrathin CoSe2 nanosheets as well as the superior conductivity of CNTs synergistically resulted in abundant active sites and enhanced conductivity to boost the electrocatalytic activity.The as-prepared CoSe2/CNTs electrocatalysts exhibited an overpotential of190 mV and 300 mV vs.reversible hydrogen electrode(RHE)at a current density of 10 mA/cm^(2) for the HER and OER in alkaline solution,respectively,and demonstrated superior durability.Furthermore,the as-prepared bifunctional CoSe2/CNTs electrocatalysts can act as cathode and anode in an electrolyzer,showing a cell voltage of 1.75 V at 10 mA/cm^(2) for overall water splitting.展开更多
Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/...Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/Mo_(2)CT_(x))to enhance the hydrogen evolution reaction(HER)and supercapacitor activities via an ionic liquid-mediated method.Se vacancy pairs and heteroatom doping enable the reallocation of local electron states and add active sites,improving the electrochemical activity of NBF-CoSe/Mo_(2)CT_(x) with high HER activities over a broad range of pH.At a current density of 10 mA cm^(-2),overvoltages of 70 and 81 mV are respectively produced in 0.5 M H_(2)SO_(4)and 1 M KOH.The optimal structure also exhibits outstanding electrochemical performance in an asymmetric supercapacitor with an energy density of 34.2 Wh kg^(-1)at a power density of 15989.6Wkg^(-1).This study opens new avenues for the introduction of Se vacancies and heteroatom doping to improve the application performance.展开更多
Hydrogen evolution reaction(HER) is a prospective method to generate pure hydrogen. The development of superior electrocatalysts based on earth-abundant materials, plays a critical role in the future.CoSe_2, one of th...Hydrogen evolution reaction(HER) is a prospective method to generate pure hydrogen. The development of superior electrocatalysts based on earth-abundant materials, plays a critical role in the future.CoSe_2, one of the earth-abundant electrocatalysts, has been proved to be a promising catalyst for hydrogen generation. In our work, flower-like CoSe_2 nanorods with high quality are successfully synthesized through a facile ethylenediaminetetraacetic acid ligand(EDTA)-assisted hydrothermal process. The flower-like CoSe_2 nanorods show the brilliant electrochemical HER performance with 100 mA cm^(-2) at overpotential of 273 m V, a small Tafel slope of 35 mV dec^(-1) and strong durability in acid solution. The sparkly HER catalytic activity of CoSe_2 can be ascribed to its particular structure with large surface area and abundant active sites. Therefore, this work offers an outstanding candidate for improving hydrogen production capabilities by water electrolysis.展开更多
Metal doping for active sites exhibits remarkable potential for improving the hydrogen evolution reaction(HER).Multi-doping and the use of a conductive substrate can further modulate catalytic performance.Herein,Nb-Co...Metal doping for active sites exhibits remarkable potential for improving the hydrogen evolution reaction(HER).Multi-doping and the use of a conductive substrate can further modulate catalytic performance.Herein,Nb-CoSe well dispersed in N-doped carbon nanospheres(NCs,Nb-CoSe@NC)was synthesized to serve as a conductive substrate and facilitated good dispersion of active sites for the HER.Nb doping can also change the electronic structure of CoSe,which facilitates the activity for the HER.In order to further improve the conductivity and intrinsic activity of Nb-CoSe@NC,dual,nonmetal doping was realized through gas sulfurization to prepare hierarchical Nb-CoSeS@NC.The prepared Nb-CoSeS@NC,with a core-shell structure,exhibited a low overpotential of 115 mV at 10 mA cm–2,which is smaller than that of the most doped catalysts.In addition,NCs not only improved the dispersion and conductivity of the catalyst but also prevented metal corrosion in an electrolyte,thus facilitating the long-term stability of Nb-CoSeS@NC.Moreover,the synergistic effect of the multi-doping of Nb,S,and Se was explained.This work provides a promising,multi-doping strategy for the large-scale application of transition-metal-based electrocatalysts for the HER.展开更多
文摘基于CoSE(cloud of secure elements)概念,提出一个NFC安全支付协议。根据CoSE架构部署一个可信云支付平台,使用虚拟SE替代硬件安全模块,所有交易项都由云支付平台完成;商户的POS终端充当消费者和云支付平台的通信桥梁,消费者的NFC设备和商户的POS终端通过射频场连接,消费者NFC设备不需要数据网络即可完成支付流程;交易过程中通过对交易双方身份信息与随机数进行hash运算,实现正常交易匿名性。通过安全性分析及实验验证了该协议的正确性和安全性。
基金funded by the National Natural Science Foundation of China,No. 30770765
文摘In this study, we investigated the effects of adenovirus-mediated transfection of PC12 cells with glucose transporter 3 after ischemic injury. The results of flow cytometry and TUNEL showed that exogenous glucose transporter 3 significantly suppressed PC12 cell apoptosis induced by ischemic injury. The results of isotopic scintiscan and western blot assays showed that, the glucose uptake rate was significantly increased and nuclear factor kappaB expression was significantly decreased after adenovirus-mediated transfection of ischemic PC12 cells with glucose transporter 3. These results suggest that adenovirus-mediated transfection of cells with glucose transporter 3 elevates the energy metabolism of PC12 cells with ischemic injury, and inhibits cell apoptosis.
基金financially supported by the National Natural Science Foundation of China (No.52371131)Beijing Nova Program (No.Z211100002121082)+2 种基金the Interdisciplinary Research Project for Young Teachers of University of Science and Technology Beijing (No.FRF-IDRY-21-013)the Project of State Key Laboratory of Explosion Science and Technology (No.QNKT23-05)Xiaomi Young Scholar Program。
文摘The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type materials.Herein,we design a current collector-integrated electrode(N-CoSe/CoSe_(2)-C@Cu) as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe_(2) heterojunction with rich Se vacancy defects,conductive sp^2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural stability.Consequently,the well-designed N-CoSe/CoSe_(2)-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g^(-1) at 0.1 A·g^(-1) after 200cycles),an exceptional rate capability(223.5 mAh·g^(-1) at2000 mA·g^(-1)),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g^(-1)).Impressively,ex situ scanning electron microscopy(SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe_(2)-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.
基金supported by the National Natural Science Foundation of China (Grant No. 51302079)the Natural Science Foundation of Hunan Province (Grant No. 2017JJ1008)
文摘One-dimensional nano-structured materials have attracted attention due to its unique properties afforded such as the across-linked structures and large aspect ratios.In this work,one-dimensional CoSe@N-doped carbon nanofibers(CoSe@NCNFs)are successfully by combining the techniques of electrospinning and annealing.Selenium powder are directly dispersed in the polyacrylonitrile/N,N-Dimethylformamide(DMF)solution containing cobalt salt to form the product.The performance of these materials was investigated in Li-ion batteries after the annealing at different temperatures.The Co Se@NC nanofibers annealed at 550℃(CoSe@NC-550)and displayed excellent storage properties,affording a high capacity of 796 m Ah·g-1at a current density of 1 A·g^-1 for 100 cycles.Moreover,it is confirmed that the pseudocapacitive contribution of CoSe@NC-550 is up to 72.8%at the scan rate of 1 mV/s through the cyclic voltammetry analysis.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.U1632151 and 21706048)the Key Research and Development Project of Anhui Province of China(Grant No.1704a0902023)the Open Project of Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices(No.JS1802)。
文摘Recently,abundant resources,low-cost sodium-ion batteries are deemed to the new-generation battery in the field of largescale energy storage.Nevertheless,poor active reaction dynamics,dissolution of intermediates and electrolyte matching problems are significant challenges that need to be solved.Herein,dimensional gradient structure of sheet-tube-dots is constructed with CoSe2@CNTs-MXene.Gradient structure is conducive to fast migration of electrons and ions with the association of ether electrolyte.For half-cell,CoSe2@CNTs-MXene exhibits high initial coulomb efficiency(81.7%)and excellent cycling performance(400 mAh g^-1 cycling for 200 times in 2 Ag^−1).Phase transformation pathway from crystalline CoSe2-Na2Se with Co and then amorphous CoSe2 in the discharge/charge process is also explored by in situ X-ray diffraction.Density functional theory study discloses the CoSe2@CNTs-MXene in ether electrolyte system which contributes to stable sodium storage performance owing to the strong adsorption force from hierarchical structure and weak interaction between electrolyte and electrode interface.For full cell,CoSe2@CNTs-MXene//Na3V2(PO4)3/C full battery can also afford a competitively reversible capacity of 280 mAh g^−1 over 50 cycles.Concisely,profiting from dimensional gradient structure and matched electrolyte of CoSe2@CNTs-MXene hold great application potential for stable sodium storage.
基金the financial support by the National Natural Science Foundation of China(No.21771137)the Key Project of Natural Science Foundation of Tianjin(No.18JCZDJC97200)+1 种基金the Training Project of Innovation Team of Colleges and Universities in Tianjin(No.TD13-5020)the start-up fund of Qilu University of Technology,Shandong Academy of Sciences。
文摘The high cost and low reserves of noble metals greatly hinder their practical applications in new energy production and conversion.The exploration of cost-effective alternative electrocatalysts with the ability to drive hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is extremely significant to promote overall water splitting.Herein,ultrathin CoSe2/CNTs nanocomposites have been synthesized by a facile two-step method,where the ultrathin Co-MOF(metal organic-framework)decorated with cable-like carbon nanotubes(CNTs)(Co-MOF/CNTs)was initially fabricated,and followed a lowtemperature selenization process.The ultrathin CoSe2 nanosheets as well as the superior conductivity of CNTs synergistically resulted in abundant active sites and enhanced conductivity to boost the electrocatalytic activity.The as-prepared CoSe2/CNTs electrocatalysts exhibited an overpotential of190 mV and 300 mV vs.reversible hydrogen electrode(RHE)at a current density of 10 mA/cm^(2) for the HER and OER in alkaline solution,respectively,and demonstrated superior durability.Furthermore,the as-prepared bifunctional CoSe2/CNTs electrocatalysts can act as cathode and anode in an electrolyzer,showing a cell voltage of 1.75 V at 10 mA/cm^(2) for overall water splitting.
基金supported by the National Natural Science Foundation of China(21905069)the Shenzhen Science and Technology Innovation Committee(JCYJ20180507183907224 and KQTD20170809110344233)the Economic,Trade and Information Commission of Shenzhen Municipality through the Graphene Manufacture Innovation Center(201901161514)。
文摘Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/Mo_(2)CT_(x))to enhance the hydrogen evolution reaction(HER)and supercapacitor activities via an ionic liquid-mediated method.Se vacancy pairs and heteroatom doping enable the reallocation of local electron states and add active sites,improving the electrochemical activity of NBF-CoSe/Mo_(2)CT_(x) with high HER activities over a broad range of pH.At a current density of 10 mA cm^(-2),overvoltages of 70 and 81 mV are respectively produced in 0.5 M H_(2)SO_(4)and 1 M KOH.The optimal structure also exhibits outstanding electrochemical performance in an asymmetric supercapacitor with an energy density of 34.2 Wh kg^(-1)at a power density of 15989.6Wkg^(-1).This study opens new avenues for the introduction of Se vacancies and heteroatom doping to improve the application performance.
基金financially supported by the National Natural Science Foundation of China (No. 21675131, 21273174)the Municipal Science Foundation of Chongqing City (No. CSTC2015jcyjB50001)
文摘Hydrogen evolution reaction(HER) is a prospective method to generate pure hydrogen. The development of superior electrocatalysts based on earth-abundant materials, plays a critical role in the future.CoSe_2, one of the earth-abundant electrocatalysts, has been proved to be a promising catalyst for hydrogen generation. In our work, flower-like CoSe_2 nanorods with high quality are successfully synthesized through a facile ethylenediaminetetraacetic acid ligand(EDTA)-assisted hydrothermal process. The flower-like CoSe_2 nanorods show the brilliant electrochemical HER performance with 100 mA cm^(-2) at overpotential of 273 m V, a small Tafel slope of 35 mV dec^(-1) and strong durability in acid solution. The sparkly HER catalytic activity of CoSe_2 can be ascribed to its particular structure with large surface area and abundant active sites. Therefore, this work offers an outstanding candidate for improving hydrogen production capabilities by water electrolysis.
文摘Metal doping for active sites exhibits remarkable potential for improving the hydrogen evolution reaction(HER).Multi-doping and the use of a conductive substrate can further modulate catalytic performance.Herein,Nb-CoSe well dispersed in N-doped carbon nanospheres(NCs,Nb-CoSe@NC)was synthesized to serve as a conductive substrate and facilitated good dispersion of active sites for the HER.Nb doping can also change the electronic structure of CoSe,which facilitates the activity for the HER.In order to further improve the conductivity and intrinsic activity of Nb-CoSe@NC,dual,nonmetal doping was realized through gas sulfurization to prepare hierarchical Nb-CoSeS@NC.The prepared Nb-CoSeS@NC,with a core-shell structure,exhibited a low overpotential of 115 mV at 10 mA cm–2,which is smaller than that of the most doped catalysts.In addition,NCs not only improved the dispersion and conductivity of the catalyst but also prevented metal corrosion in an electrolyte,thus facilitating the long-term stability of Nb-CoSeS@NC.Moreover,the synergistic effect of the multi-doping of Nb,S,and Se was explained.This work provides a promising,multi-doping strategy for the large-scale application of transition-metal-based electrocatalysts for the HER.
