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
In this paper,the experimental investigation on the performance improvement of conventional stepped solar still is conducted.The steps are covered by the porous material to improve the performance of the conventional ...In this paper,the experimental investigation on the performance improvement of conventional stepped solar still is conducted.The steps are covered by the porous material to improve the performance of the conventional device and increase the evaporation rate.All the parameters,including the temperature on the glass surface,the water temperature inside the evaporation zone,and the amount of water produced in both conventional and modified stepped solar stills are measured and compared.The efficiency of two devices and their exergy efficiency have been calculated.Finally,the economic analysis of both devices has been done to check the economic feasibility of the modified device.The amount of freshwater generated during one day was 2244.4 and 3076.2 mL/m^(2),respectively for the conventional and modified stepped solar stills.As a result,the amount of water produced in one day by modified stepped solar still is 35.5% more than the conventional one.Also,the costs for the conventional and modified stepped solar stills have been calculated as 0.0359 and 0.029$/(L·m^(-2)),respectively.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
Since the launch in June 2017,Insight-HXMT has been in service smoothly in orbit and particularly productive in 2023 and 2024.Among a total number of 238 papers published so far based on Insight-HXMT data,63 were publ...Since the launch in June 2017,Insight-HXMT has been in service smoothly in orbit and particularly productive in 2023 and 2024.Among a total number of 238 papers published so far based on Insight-HXMT data,63 were published in 2023,and 32 in the early 2024(till 2024 April),accounting for 40%of the total.These studies cover a variety of scientific subjects including the basic properties of black holes and neutron stars,the outburst of accreting black hole and neutron star X-ray binaries,thermal nuclear burst probes,isolated pulsars,quasi periodical oscillations,cyclotron resonant scattering features,fast radio bursts and gamma-ray bursts,etc.This paper introduces the overall progress with focus on some potential breakthroughs.展开更多
本研究采用C57black/6小鼠制备全脑缺血模型,观察脑缺血后多个脑区Bax和Bcl-2基因的表达。双侧颈总动脉夹闭(bilateral common carotid artery occlusion,BCCAO)15min,造成全脑缺血,24h后取脑组织进行Bax和Bcl-2免疫组织化学染色。结果...本研究采用C57black/6小鼠制备全脑缺血模型,观察脑缺血后多个脑区Bax和Bcl-2基因的表达。双侧颈总动脉夹闭(bilateral common carotid artery occlusion,BCCAO)15min,造成全脑缺血,24h后取脑组织进行Bax和Bcl-2免疫组织化学染色。结果显示:Bax阳性细胞广泛分布在大脑皮层、丘脑和杏仁核,阳性产物主要位于胞质内。除丘脑外,其他各部位Bax阳性神经元的密度缺血组均显著高于假手术组(P<0.05);缺血组各区域细胞染色灰度值均显著低于假手术组(P<0.01)。Bcl-2阳性细胞在大脑皮层和丘脑均有表达,缺血组大脑皮层内Bcl-2阳性神经元的密度显著高于假手术组(P<0.05);缺血组各区域细胞染色灰度值均显著低于假手术组(P<0.01)。以上结果表明双侧颈总动脉夹闭法致C57black/6小鼠全脑缺血模型可致多脑区Bax和Bcl-2的广泛表达,提示Bax和Bcl-2可能介导了缺血所致的神经元损伤。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In this paper,the experimental investigation on the performance improvement of conventional stepped solar still is conducted.The steps are covered by the porous material to improve the performance of the conventional device and increase the evaporation rate.All the parameters,including the temperature on the glass surface,the water temperature inside the evaporation zone,and the amount of water produced in both conventional and modified stepped solar stills are measured and compared.The efficiency of two devices and their exergy efficiency have been calculated.Finally,the economic analysis of both devices has been done to check the economic feasibility of the modified device.The amount of freshwater generated during one day was 2244.4 and 3076.2 mL/m^(2),respectively for the conventional and modified stepped solar stills.As a result,the amount of water produced in one day by modified stepped solar still is 35.5% more than the conventional one.Also,the costs for the conventional and modified stepped solar stills have been calculated as 0.0359 and 0.029$/(L·m^(-2)),respectively.
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.
基金Supported partially by the National Key R&D Program of China(2021YFA0718500)the National Natural Science Foundation(Grant No.12333007,12027803)International Partnership Program of Chinese Academy of Sciences(Grant No.113111KYSB20190020)。
文摘Since the launch in June 2017,Insight-HXMT has been in service smoothly in orbit and particularly productive in 2023 and 2024.Among a total number of 238 papers published so far based on Insight-HXMT data,63 were published in 2023,and 32 in the early 2024(till 2024 April),accounting for 40%of the total.These studies cover a variety of scientific subjects including the basic properties of black holes and neutron stars,the outburst of accreting black hole and neutron star X-ray binaries,thermal nuclear burst probes,isolated pulsars,quasi periodical oscillations,cyclotron resonant scattering features,fast radio bursts and gamma-ray bursts,etc.This paper introduces the overall progress with focus on some potential breakthroughs.
文摘本研究采用C57black/6小鼠制备全脑缺血模型,观察脑缺血后多个脑区Bax和Bcl-2基因的表达。双侧颈总动脉夹闭(bilateral common carotid artery occlusion,BCCAO)15min,造成全脑缺血,24h后取脑组织进行Bax和Bcl-2免疫组织化学染色。结果显示:Bax阳性细胞广泛分布在大脑皮层、丘脑和杏仁核,阳性产物主要位于胞质内。除丘脑外,其他各部位Bax阳性神经元的密度缺血组均显著高于假手术组(P<0.05);缺血组各区域细胞染色灰度值均显著低于假手术组(P<0.01)。Bcl-2阳性细胞在大脑皮层和丘脑均有表达,缺血组大脑皮层内Bcl-2阳性神经元的密度显著高于假手术组(P<0.05);缺血组各区域细胞染色灰度值均显著低于假手术组(P<0.01)。以上结果表明双侧颈总动脉夹闭法致C57black/6小鼠全脑缺血模型可致多脑区Bax和Bcl-2的广泛表达,提示Bax和Bcl-2可能介导了缺血所致的神经元损伤。
