Ammonium-ion hybrid supercapacitors(A-HSCs)have emerged as promising candidates for next-generation energy storage owing to their inherent safety and environmental sustainability.Hexagonal tungsten oxide(h-WO_(3)),wit...Ammonium-ion hybrid supercapacitors(A-HSCs)have emerged as promising candidates for next-generation energy storage owing to their inherent safety and environmental sustainability.Hexagonal tungsten oxide(h-WO_(3)),with its well-defined tunnel structure,holds great promise as a negative electrode material for NH^(4+)storage.However,its practical application is hindered by structural instability and poor intrinsic electrical conductivity.To address these challenges,a dual-regulation strategy is proposed,integrating molybdenum(Mo)doping and NH^(4+)pre-intercalation to concurrently optimize the tunnel structure and electronic environment of h-WO_(3)(Mo-NWO).Comprehensive experimental and theoretical analyses reveal that Mo doping narrows the bandgap of WO_(3)and reduces the diffusion energy barrier,thereby accelerating NH^(4+)adsorption and diffusion.Simultaneously,NH^(4+)pre-intercalation stabilizes the tunnel framework via hydrogen bonding,ensuring structural reversibility.As expected,the Mo-NWO/AC electrode achieves a high areal capacitance of 13.6 F cm^(−2)at 5 mA cm^(−2)and retains 80.14%of its capacitance after 5000 cycles,demonstrating exceptional rate capability and cycling stability.Moreover,the assembled Mn_(3)O_(4)//Mo-NWO/AC device delivers a high energy density of 3.41 mWh cm^(−2)and outstanding long-term stability(85.75%retention after 12,000 cycles).This work provides a viable strategy for designing high-performance NH^(4+)storage materials and advances the development of sustainable energy storage systems.展开更多
Herein,a novel Janus-structured multifunctional membrane with integrated electromagnetic interference(EMI)shielding and personalized thermal management is fabricated using shear-induced in situ fibrillation and vacuum...Herein,a novel Janus-structured multifunctional membrane with integrated electromagnetic interference(EMI)shielding and personalized thermal management is fabricated using shear-induced in situ fibrillation and vacuum-assisted filtration.Interestingly,within the polytetrafluoroethylene(PTFE)-carbon nanotube(CNT)-Fe_(3)O_(4)layer(FCFe),CNT nanofibers interweave with PTFE fibers to form a stable“silk-like”structure that effectively captures Fe_(3)O_(4)particles.By incorporating a highly conductive MXene layer,the FCFe/MXene(FCFe/M)membrane exhibits excellent electrical/thermal conductivity,mechanical properties,and flame retardancy.Impressively,benefiting from the rational regulation of component proportions and the design of a Janus structure,the FCFe/M membrane with a thickness of only 84.9μm delivers outstanding EMI shielding effectiveness of 44.56 dB in the X-band,with a normalized specific SE reaching 10,421.3 dB cm^(2)g^(-1),which is attributed to the“absorption-reflection-reabsorption”mechanism.Furthermore,the membrane demonstrates low-voltage-driven Joule heating and fast-response photothermal performance.Under the stimulation of a 3 V voltage and an optical power density of 320 mW cm^(-2),the surface temperatures of the FCFe/M membranes can reach up to 140.4 and 145.7℃,respectively.In brief,the FCFe/M membrane with anti-electromagnetic radiation and temperature regulation is an attractive candidate for the next generation of wearable electronics,EMI compatibility,visual heating,thermotherapy,and military and aerospace applications.展开更多
In an environment where demand for housing is growing and the supply from public authorities is virtually non-existent,several mechanisms for housing production are emerging in the formal,semi-informal and informal co...In an environment where demand for housing is growing and the supply from public authorities is virtually non-existent,several mechanisms for housing production are emerging in the formal,semi-informal and informal construction sectors.The project owner wonders how much it costs to construct a building to an acceptable standard.Cost forecasting in general faces a number of difficulties,including a lack of available information during the preliminary phase of the project.As such,estimation becomes a crucial task involving great responsibility,which can lead to either more convincing results or chaotic situations.This study proposes a quick and effective method for estimating the cost of a single-storey F4 residential building.The modelling is done using multiple linear regression based on a statistical approach applied to twenty(20)projects that have already been completed.The project data are collected from design offices in the city of Brazzaville.The method expresses the cost of an F4 construction by certain project tasks,representing five(5)variables,three(3)of which are related to structural work and two(2)to finishing work,which are easy to determine.This approach,known as MECSO(Cost Estimation Model by Sub-structure),gives good results in all statistical tests carried out with reasonable confidence intervals.This method is very practical for engineering professionals working on the evaluation and control of construction costs.展开更多
The impact of rolling temperature and the crystallographic orientation ofα-colonies on the globularization behavior of lamellarα+βmicrostructure in Ti-6Al-4V alloy was investigated.Firstly,the lamellar structure wa...The impact of rolling temperature and the crystallographic orientation ofα-colonies on the globularization behavior of lamellarα+βmicrostructure in Ti-6Al-4V alloy was investigated.Firstly,the lamellar structure was heavily rolled at 600,700,800 and 900°C,respectively.Heavy rolling from temperatures of 600 to 900°C resulted in an increased volume fraction and thickness ofβlamellae,while the corresponding parameters forαlamellae decreased.Then,these rolledα+βlamellar microstructures were spheroidized into equiaxed grains upon subsequent annealing.The results demonstrate that the globularization fraction of the lamellar structures diminishes as the rolling temperature increases.Additionally,the globularization fraction forα-colonies with hard crystallographic orientations,such as<0001>//ND and<0001>//TD,is considerably lower compared to those with softer orientations,positioned at certain angles to ND,RD,and TD during annealing process.This results in heterogeneous globularization ofαlamellae,leading to the development of pronounced sharp micro-texture.Furthermore,the slipping deformations ofα-colonies with varying crystallographic orientations during rolling were meticulously analyzed.展开更多
Designing catalysts with high reaction efficiency is essential for reducing heavy metal Cr(VI)ions in wastewater via microwave induction.In this paper,a unique microwave-responsive lychee-like Ni/C/ZnFe_(2)O_(4) compo...Designing catalysts with high reaction efficiency is essential for reducing heavy metal Cr(VI)ions in wastewater via microwave induction.In this paper,a unique microwave-responsive lychee-like Ni/C/ZnFe_(2)O_(4) composite catalyst with a double-shell hollow porous heterojunction structure was constructed for the efficient reduction of Cr(VI).Benefiting from the novel hollow porous structure and“carbon nanocage”structure of the Ni/C/ZnFe_(2)O_(4),coupled with excellent electromagnetic wave absorption ability,the prepared lychee-like Ni/C/ZnFe_(2)O_(4) com-posite catalyst could remove up to 98%of Cr(VI)(50 mg L 1,50 mL)after 40 min of microwave irradiation,even in nearly neutral water conditions.Additionally,density functional theory calculations indicated that the heterojunction interface between Ni/C and ZnFe_(2)O_(4) enhances electron transfer from ZnFe_(2)O_(4) to Ni/C,ultimately facilitating the removal of Cr(VI).Furthermore,the incorporation of Ni/C facilitated the 2 acceleration of H ion transfer to*Cr_(2)O_(7),thereby expediting the conversion kinetics of the latter.This research aims to establish a theoretical and experimental foundation for the effective and stable microwave-assisted catalytic reduction of heavy metal Cr(VI)ions,presenting new insights and methods to combat heavy metal contamination.展开更多
基金supported by the National Natural Science Foundation of Guangxi Province(2024GXNSFBA010033)the Special Fund for Science and Technology Development of Guangxi(Grant No.AD25069078).
文摘Ammonium-ion hybrid supercapacitors(A-HSCs)have emerged as promising candidates for next-generation energy storage owing to their inherent safety and environmental sustainability.Hexagonal tungsten oxide(h-WO_(3)),with its well-defined tunnel structure,holds great promise as a negative electrode material for NH^(4+)storage.However,its practical application is hindered by structural instability and poor intrinsic electrical conductivity.To address these challenges,a dual-regulation strategy is proposed,integrating molybdenum(Mo)doping and NH^(4+)pre-intercalation to concurrently optimize the tunnel structure and electronic environment of h-WO_(3)(Mo-NWO).Comprehensive experimental and theoretical analyses reveal that Mo doping narrows the bandgap of WO_(3)and reduces the diffusion energy barrier,thereby accelerating NH^(4+)adsorption and diffusion.Simultaneously,NH^(4+)pre-intercalation stabilizes the tunnel framework via hydrogen bonding,ensuring structural reversibility.As expected,the Mo-NWO/AC electrode achieves a high areal capacitance of 13.6 F cm^(−2)at 5 mA cm^(−2)and retains 80.14%of its capacitance after 5000 cycles,demonstrating exceptional rate capability and cycling stability.Moreover,the assembled Mn_(3)O_(4)//Mo-NWO/AC device delivers a high energy density of 3.41 mWh cm^(−2)and outstanding long-term stability(85.75%retention after 12,000 cycles).This work provides a viable strategy for designing high-performance NH^(4+)storage materials and advances the development of sustainable energy storage systems.
基金support from the National Natural Science Foundation of China(NSFC,Grant No.52175341)Shandong Provincial Natural Science Foundation(Grant No.ZR2022JQ24)Funding Project of Jinan City’s New Twenty Items for Colleges and Universities(Grant No.202333038).
文摘Herein,a novel Janus-structured multifunctional membrane with integrated electromagnetic interference(EMI)shielding and personalized thermal management is fabricated using shear-induced in situ fibrillation and vacuum-assisted filtration.Interestingly,within the polytetrafluoroethylene(PTFE)-carbon nanotube(CNT)-Fe_(3)O_(4)layer(FCFe),CNT nanofibers interweave with PTFE fibers to form a stable“silk-like”structure that effectively captures Fe_(3)O_(4)particles.By incorporating a highly conductive MXene layer,the FCFe/MXene(FCFe/M)membrane exhibits excellent electrical/thermal conductivity,mechanical properties,and flame retardancy.Impressively,benefiting from the rational regulation of component proportions and the design of a Janus structure,the FCFe/M membrane with a thickness of only 84.9μm delivers outstanding EMI shielding effectiveness of 44.56 dB in the X-band,with a normalized specific SE reaching 10,421.3 dB cm^(2)g^(-1),which is attributed to the“absorption-reflection-reabsorption”mechanism.Furthermore,the membrane demonstrates low-voltage-driven Joule heating and fast-response photothermal performance.Under the stimulation of a 3 V voltage and an optical power density of 320 mW cm^(-2),the surface temperatures of the FCFe/M membranes can reach up to 140.4 and 145.7℃,respectively.In brief,the FCFe/M membrane with anti-electromagnetic radiation and temperature regulation is an attractive candidate for the next generation of wearable electronics,EMI compatibility,visual heating,thermotherapy,and military and aerospace applications.
文摘In an environment where demand for housing is growing and the supply from public authorities is virtually non-existent,several mechanisms for housing production are emerging in the formal,semi-informal and informal construction sectors.The project owner wonders how much it costs to construct a building to an acceptable standard.Cost forecasting in general faces a number of difficulties,including a lack of available information during the preliminary phase of the project.As such,estimation becomes a crucial task involving great responsibility,which can lead to either more convincing results or chaotic situations.This study proposes a quick and effective method for estimating the cost of a single-storey F4 residential building.The modelling is done using multiple linear regression based on a statistical approach applied to twenty(20)projects that have already been completed.The project data are collected from design offices in the city of Brazzaville.The method expresses the cost of an F4 construction by certain project tasks,representing five(5)variables,three(3)of which are related to structural work and two(2)to finishing work,which are easy to determine.This approach,known as MECSO(Cost Estimation Model by Sub-structure),gives good results in all statistical tests carried out with reasonable confidence intervals.This method is very practical for engineering professionals working on the evaluation and control of construction costs.
文摘The impact of rolling temperature and the crystallographic orientation ofα-colonies on the globularization behavior of lamellarα+βmicrostructure in Ti-6Al-4V alloy was investigated.Firstly,the lamellar structure was heavily rolled at 600,700,800 and 900°C,respectively.Heavy rolling from temperatures of 600 to 900°C resulted in an increased volume fraction and thickness ofβlamellae,while the corresponding parameters forαlamellae decreased.Then,these rolledα+βlamellar microstructures were spheroidized into equiaxed grains upon subsequent annealing.The results demonstrate that the globularization fraction of the lamellar structures diminishes as the rolling temperature increases.Additionally,the globularization fraction forα-colonies with hard crystallographic orientations,such as<0001>//ND and<0001>//TD,is considerably lower compared to those with softer orientations,positioned at certain angles to ND,RD,and TD during annealing process.This results in heterogeneous globularization ofαlamellae,leading to the development of pronounced sharp micro-texture.Furthermore,the slipping deformations ofα-colonies with varying crystallographic orientations during rolling were meticulously analyzed.
基金financially supported by National Natural Science Foundation of China(Grant No.52272021,52232002 and U23A20559)Natural Science Foundation of Wuhan(2024040701010051)+1 种基金Program for Innovative Teams of Outstanding Young and Middle-aged Researchers in the Higher Education Institutions of Hubei Province(T201602)The work was supported by the Open Fund of the Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control,Ministry of Ecology and Environment of the People's Republic of China(No.HB202402)。
文摘Designing catalysts with high reaction efficiency is essential for reducing heavy metal Cr(VI)ions in wastewater via microwave induction.In this paper,a unique microwave-responsive lychee-like Ni/C/ZnFe_(2)O_(4) composite catalyst with a double-shell hollow porous heterojunction structure was constructed for the efficient reduction of Cr(VI).Benefiting from the novel hollow porous structure and“carbon nanocage”structure of the Ni/C/ZnFe_(2)O_(4),coupled with excellent electromagnetic wave absorption ability,the prepared lychee-like Ni/C/ZnFe_(2)O_(4) com-posite catalyst could remove up to 98%of Cr(VI)(50 mg L 1,50 mL)after 40 min of microwave irradiation,even in nearly neutral water conditions.Additionally,density functional theory calculations indicated that the heterojunction interface between Ni/C and ZnFe_(2)O_(4) enhances electron transfer from ZnFe_(2)O_(4) to Ni/C,ultimately facilitating the removal of Cr(VI).Furthermore,the incorporation of Ni/C facilitated the 2 acceleration of H ion transfer to*Cr_(2)O_(7),thereby expediting the conversion kinetics of the latter.This research aims to establish a theoretical and experimental foundation for the effective and stable microwave-assisted catalytic reduction of heavy metal Cr(VI)ions,presenting new insights and methods to combat heavy metal contamination.
