Metal phosphides have been studied as prospective anode materials for sodium-ion batteries(SIBs)due to their higher specific capacity compared to other anode materials.However,rapid capacity decay and limited cycle li...Metal phosphides have been studied as prospective anode materials for sodium-ion batteries(SIBs)due to their higher specific capacity compared to other anode materials.However,rapid capacity decay and limited cycle life caused by volume expansion and low electrical conductivity of phosphides in SIBs remain still unsolved.To address these issues,GeP_(3) was first prepared by high-energy ball milling,and then Ketjen black(KB)was introduced to synthesize composite GeP_(3)/KB anode materials under controlled milling speed and time by a secondary ball milling process.During the ball milling process,GeP_(3) and KB form strong chemical bonds,resulting in a closely bonded composite.Consequently,the GeP_(3)/KB anodes was demonstrated excellent sodium storage performance,achieving a high reversible capacity of 933.41 mAh·g^(–1) at a current density of 0.05 A·g^(–1) for a special formula of GeP_(3)/KB-600-40 sample prepared at ball milling speed of 600 r/min for 40 h.Even at a high current density of 2 A·g^(–1) over 200 cycles,the capacity remains 314.52 mAh·g^(–1) with a retention rate of 66.6%.In conclusion,this work successfully prepares GeP_(3)/KB anode-carbon composite for electrodes by high-energy ball milling,which can restrict electrode volume expansion,enhance capacity,and improve cycle stability of SIBs.展开更多
The advancement of planar micro-supercapacitors(PMSCs)for micro-electromechanical systems(MEMS)has been significantly hindered by the challenge of achieving high energy and power densities.This study addresses this is...The advancement of planar micro-supercapacitors(PMSCs)for micro-electromechanical systems(MEMS)has been significantly hindered by the challenge of achieving high energy and power densities.This study addresses this issue by leveraging screen-printing technology to fabricate high-performance PMSCs using innovative composite ink.The ink,a synergistic blend of few-layer graphene(Gt),carbon black(CB),and NiCo_(2)O_(4),was meticulously mixed to form a conductive and robust coating that enhanced the capacitive performance of the PMSCs.The optimized ink formulation and printing process result in a micro-supercapacitor with an exceptional areal capacitance of 18.95 mF/cm^(2)and an areal energy density of 2.63μW·h/cm^(2)at a current density of 0.05 mA/cm^(2),along with an areal power density of 0.025 mW/cm^(2).The devices demonstrated impressive durability with a capacitance retention rate of 94.7%after a stringent 20000-cycle test,demonstrating their potential for long-term applications.Moreover,the PMSCs displayed excellent mechanical flexibility,with a capacitance decrease of only 3.43%after 5000 bending cycles,highlighting their suitability for flexible electronic devices.The ease of integrating these PMSCs into series and parallel configurations for customized power further underscores their practicality for integrated power supply solutions in various technologies.展开更多
Using the synchronous coordinates,the creation of a Schwarzschild black hole immersed in a de Sitter spacetime can be viewed as a coherent creation of a collection of timelike geodesics.The previously supposed conical...Using the synchronous coordinates,the creation of a Schwarzschild black hole immersed in a de Sitter spacetime can be viewed as a coherent creation of a collection of timelike geodesics.The previously supposed conical singularities do not exist at the horizons of the constrained instanton.Instead,the unavoidable irregularity is presented as a nonvanishing second fundamental form elsewhere at the quantum transition 3-surface.The same arguments can be applied to charged,topological,or higher dimensional black hole cases.展开更多
采用顶空固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)技术、16 S rRNA和内在转录间隔区(ITS)高通量测序技术,探究了安化红茶的深发酵和浅发酵工艺过程中红茶的香气特征成分和微生物多样性。结果表明,在不同发酵工艺的安化红茶中共检测...采用顶空固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)技术、16 S rRNA和内在转录间隔区(ITS)高通量测序技术,探究了安化红茶的深发酵和浅发酵工艺过程中红茶的香气特征成分和微生物多样性。结果表明,在不同发酵工艺的安化红茶中共检测出82种挥发性成分,主要为醇类、酯类和醛类,占比约为85%;挥发性成分总量随着加工过程的进行呈现先增加后降低的趋势。以气味活度值(OAV)>1且变量投影重要性(VIP)>1为依据,在浅发酵与深发酵工艺的安化红茶中筛选出柠檬醛、芳樟醇、苯乙醇、苯乙醛、水杨酸甲酯、β-月桂烯等14种关键差异挥发性成分。安化红茶的优势细菌为鞘氨醇单胞菌属(Sphingomonas)、甲基杆菌属(Methylobacterium)、橙黄单胞菌属(Aureimonas),优势真菌为枝孢属(Cladosporium)、链格孢属(Alternaria)、Setophoma。橙黄单胞菌属、肠杆菌属(Enterobacter)、曲霉属(Aspergillus)、Pseudopithomyces与不同发酵过程显著相关。研究结果为安化红茶科学加工、风味解析提供理论参考与依据。展开更多
基金National Natural Science Foundation of China Young Scientist Fund(22105120)Shaanxi Province Qin Chuangyuan“Scientist+Engineer”Team Construction Project(2024QCY-KXJ-127)。
文摘Metal phosphides have been studied as prospective anode materials for sodium-ion batteries(SIBs)due to their higher specific capacity compared to other anode materials.However,rapid capacity decay and limited cycle life caused by volume expansion and low electrical conductivity of phosphides in SIBs remain still unsolved.To address these issues,GeP_(3) was first prepared by high-energy ball milling,and then Ketjen black(KB)was introduced to synthesize composite GeP_(3)/KB anode materials under controlled milling speed and time by a secondary ball milling process.During the ball milling process,GeP_(3) and KB form strong chemical bonds,resulting in a closely bonded composite.Consequently,the GeP_(3)/KB anodes was demonstrated excellent sodium storage performance,achieving a high reversible capacity of 933.41 mAh·g^(–1) at a current density of 0.05 A·g^(–1) for a special formula of GeP_(3)/KB-600-40 sample prepared at ball milling speed of 600 r/min for 40 h.Even at a high current density of 2 A·g^(–1) over 200 cycles,the capacity remains 314.52 mAh·g^(–1) with a retention rate of 66.6%.In conclusion,this work successfully prepares GeP_(3)/KB anode-carbon composite for electrodes by high-energy ball milling,which can restrict electrode volume expansion,enhance capacity,and improve cycle stability of SIBs.
基金supported by the Shanxi Province Central Guidance Fund for Local Science and Technology Development Project(YDZJSX2024D030)the National Natural Science Foundation of China(22075197,22278290)+2 种基金the Shanxi Province Key Research and Development Program Project(2021020660301013)the Shanxi Provincial Natural Science Foundation of China(202103021224079)the Research and Development Project of Key Core and Common Technology of Shanxi Province(20201102018).
文摘The advancement of planar micro-supercapacitors(PMSCs)for micro-electromechanical systems(MEMS)has been significantly hindered by the challenge of achieving high energy and power densities.This study addresses this issue by leveraging screen-printing technology to fabricate high-performance PMSCs using innovative composite ink.The ink,a synergistic blend of few-layer graphene(Gt),carbon black(CB),and NiCo_(2)O_(4),was meticulously mixed to form a conductive and robust coating that enhanced the capacitive performance of the PMSCs.The optimized ink formulation and printing process result in a micro-supercapacitor with an exceptional areal capacitance of 18.95 mF/cm^(2)and an areal energy density of 2.63μW·h/cm^(2)at a current density of 0.05 mA/cm^(2),along with an areal power density of 0.025 mW/cm^(2).The devices demonstrated impressive durability with a capacitance retention rate of 94.7%after a stringent 20000-cycle test,demonstrating their potential for long-term applications.Moreover,the PMSCs displayed excellent mechanical flexibility,with a capacitance decrease of only 3.43%after 5000 bending cycles,highlighting their suitability for flexible electronic devices.The ease of integrating these PMSCs into series and parallel configurations for customized power further underscores their practicality for integrated power supply solutions in various technologies.
文摘Using the synchronous coordinates,the creation of a Schwarzschild black hole immersed in a de Sitter spacetime can be viewed as a coherent creation of a collection of timelike geodesics.The previously supposed conical singularities do not exist at the horizons of the constrained instanton.Instead,the unavoidable irregularity is presented as a nonvanishing second fundamental form elsewhere at the quantum transition 3-surface.The same arguments can be applied to charged,topological,or higher dimensional black hole cases.
文摘采用顶空固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)技术、16 S rRNA和内在转录间隔区(ITS)高通量测序技术,探究了安化红茶的深发酵和浅发酵工艺过程中红茶的香气特征成分和微生物多样性。结果表明,在不同发酵工艺的安化红茶中共检测出82种挥发性成分,主要为醇类、酯类和醛类,占比约为85%;挥发性成分总量随着加工过程的进行呈现先增加后降低的趋势。以气味活度值(OAV)>1且变量投影重要性(VIP)>1为依据,在浅发酵与深发酵工艺的安化红茶中筛选出柠檬醛、芳樟醇、苯乙醇、苯乙醛、水杨酸甲酯、β-月桂烯等14种关键差异挥发性成分。安化红茶的优势细菌为鞘氨醇单胞菌属(Sphingomonas)、甲基杆菌属(Methylobacterium)、橙黄单胞菌属(Aureimonas),优势真菌为枝孢属(Cladosporium)、链格孢属(Alternaria)、Setophoma。橙黄单胞菌属、肠杆菌属(Enterobacter)、曲霉属(Aspergillus)、Pseudopithomyces与不同发酵过程显著相关。研究结果为安化红茶科学加工、风味解析提供理论参考与依据。
