The Li-Mg-N-H(Mg(NH_(2))_(2)-2LiH)system,as a high-capacity Mg-based metal hydrogen storage material(5.6 wt%),has broad prospects for in vehicle hydrogen storage applications,but it still has high hydrogen ab/desorpti...The Li-Mg-N-H(Mg(NH_(2))_(2)-2LiH)system,as a high-capacity Mg-based metal hydrogen storage material(5.6 wt%),has broad prospects for in vehicle hydrogen storage applications,but it still has high hydrogen ab/desorption barriers.To improve its hydrogen storage performance,a nanohydrogen storage alloy was innovatively combined with Mg(NH_(2))_(2)-2LiH,AB5 type nanohydrogen storage alloy LaNi_(5)was prepared by co-precipitation method.Nano LaNi_(5)and single-walled carbon nanotubes(SWCNTs)were co-doped into the Mg(NH_(2))_(2)-2LiH system at a ratio of 10 wt%and 2 wt%,significantly enhancing the hydrogen storage performance of Mg(NH_(2))_(2)-2LiH.The initial hydrogen ab/desorption temperatures of the co-doped system decreased from110/130℃to 45/85℃.The release of by-product ammonia is significantly inhibited.4.73 wt% H_(2)can be ab/desorption in 150 min at 180/170℃.Cycle tests show that the co-doped system can still maintain a hydrogen storage capacity of 4.75 wt% after ten hydrogen release cycles.Mechanism and density functional theory study have shown that during the hydrogen release process,partially hydrogenated LaNi_(5)weakens the chemical bonding in Mg(NH_(2))_(2),promoted the dissociation of hydrogen from the Mg(NH_(2))_(2)-2LiH system,while playing a dual role of"hydrogen overflow"and"hydrogen pump".SWCNTs act as auxiliary agents,helping to refine particle size and increase thermal conductivity.The synergistic effect of the two optimizes the comprehensive hydrogen storage performance of Mg(NH_(2))_(2)-2LiH.This study provides a new research method for improving the comprehensive hydrogen storage performance of Mg-based metal hydrogen storage materials using rare earth element catalysts.展开更多
Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the eff...Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.展开更多
针对在室温环境下探测瓦斯浓度,提出一种基于钯掺杂单壁碳纳米管(Pd-SWCNTs)的超宽带射频识别(UWB-RFID)传感器。传感器为薄型标签,由传感探头和电磁界面组成,其中传感探头为一PdSWCNTs加载的交叉指型电极(IDE);电磁界面由天线、微带线...针对在室温环境下探测瓦斯浓度,提出一种基于钯掺杂单壁碳纳米管(Pd-SWCNTs)的超宽带射频识别(UWB-RFID)传感器。传感器为薄型标签,由传感探头和电磁界面组成,其中传感探头为一PdSWCNTs加载的交叉指型电极(IDE);电磁界面由天线、微带线和终端负载组成。Pd-SWCNTs感知瓦斯浓度,引起IDE电流的变化,形成带隙幅度调制和带隙频率调制两种识别模式。当瓦斯浓度从0×10-6增加到100×10-6,基于带隙调幅调制的识别灵敏度为-9.32 d B;而基于带隙调频调制的识别灵敏度为-11.30 d B。展开更多
A new SnO2-Fe2O3/SWCNTs（single-walled carbon nanotubes） ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles（NPs） were homogeneously located on the surface of ...A new SnO2-Fe2O3/SWCNTs（single-walled carbon nanotubes） ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles（NPs） were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction（XRD）,transmission electron microscope（TEM） and energy dispersive X-ray spectroscopy（EDX）.Due to the synergistic effect of different components,the as synthesized SnO2-Fe2O3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g-1 which could be maintained after 50 cycles at 200 mA·g-1.Even at a high rate of2000 mA·g-1,the capacity was still remained at 656 mAh·g-1.展开更多
This work aims to study magnetohydrodynamic flow through a circular cylinder in a horizontal position of SWCNTs in blood as a base fluid in the existence of non-linear thermal radiation and heat source/sink.Three kind...This work aims to study magnetohydrodynamic flow through a circular cylinder in a horizontal position of SWCNTs in blood as a base fluid in the existence of non-linear thermal radiation and heat source/sink.Three kinds of nanoparticles shapes are considered.The study is employed the finite element technique to explore and enhance the influences of essential parameters on temperature profiles and is debated the heat transport within blood injects with SWCNTs and exposes to electromagnetic radiation.The treatment with thermal analysis and heat transfer rate being a better substitute more than surgery and chemotherapy for cancer therapy.Utilizing of nanoparticles thermal features is a mounting area of nanomedicine field because of the probable for purposeful demolition of cancer cells.This remedy is relied on many parameters,including nanofluid thermal conductivity,nanoparticles volume fraction,thermal radiation and power and heat source.The numerical solutions for flow and heat transfer features are assessed for diverse governing parameters values.The obtained results are substantiated against the relevant numerical results in the published researches.Results show that both flow velocity and temperature increase for larger values of thermal radiation,heat source and SWCNTs volume fraction with lamina and cylinder shapes.Also,spherical shape of SWCNTs occurs high disturbances in velocity and temperature distribution in the case of cooled cylinder.展开更多
电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量...电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51971199 and 51771171)
文摘The Li-Mg-N-H(Mg(NH_(2))_(2)-2LiH)system,as a high-capacity Mg-based metal hydrogen storage material(5.6 wt%),has broad prospects for in vehicle hydrogen storage applications,but it still has high hydrogen ab/desorption barriers.To improve its hydrogen storage performance,a nanohydrogen storage alloy was innovatively combined with Mg(NH_(2))_(2)-2LiH,AB5 type nanohydrogen storage alloy LaNi_(5)was prepared by co-precipitation method.Nano LaNi_(5)and single-walled carbon nanotubes(SWCNTs)were co-doped into the Mg(NH_(2))_(2)-2LiH system at a ratio of 10 wt%and 2 wt%,significantly enhancing the hydrogen storage performance of Mg(NH_(2))_(2)-2LiH.The initial hydrogen ab/desorption temperatures of the co-doped system decreased from110/130℃to 45/85℃.The release of by-product ammonia is significantly inhibited.4.73 wt% H_(2)can be ab/desorption in 150 min at 180/170℃.Cycle tests show that the co-doped system can still maintain a hydrogen storage capacity of 4.75 wt% after ten hydrogen release cycles.Mechanism and density functional theory study have shown that during the hydrogen release process,partially hydrogenated LaNi_(5)weakens the chemical bonding in Mg(NH_(2))_(2),promoted the dissociation of hydrogen from the Mg(NH_(2))_(2)-2LiH system,while playing a dual role of"hydrogen overflow"and"hydrogen pump".SWCNTs act as auxiliary agents,helping to refine particle size and increase thermal conductivity.The synergistic effect of the two optimizes the comprehensive hydrogen storage performance of Mg(NH_(2))_(2)-2LiH.This study provides a new research method for improving the comprehensive hydrogen storage performance of Mg-based metal hydrogen storage materials using rare earth element catalysts.
基金National Key Research and Development Program of China(2023YFB4606400)Supported by Longmen Laboratory Frontier Exploration Topics(LMQYTSKT003)。
文摘Copper manufactured by laser powder bed fusion(LPBF)process typically exhibits poor strength-ductility coordination,and the addition of strengthening phases is an effective way to address this issue.To explore the effects of strengthening phases on Cu,Cu-carbon nanotubes(CNTs)composites were prepared using LPBF technique with Cu-CNTs mixed powder as the matrix.The formability,microstructure,mechanical properties,electrical conductivity,and thermal properties were studied.The result shows that the prepared composites have high relative density.The addition of CNTs results in inhomogeneous equiaxed grains at the edges of the molten pool and columnar grains at the center.Compared with pure copper,the overall mechanical properties of the composite are improved:tensile strength increases by 52.8%and elongation increases by 146.4%;the electrical and thermal properties are also enhanced:thermal conductivity increases by 10.8%and electrical conductivity increases by 12.7%.
文摘针对在室温环境下探测瓦斯浓度,提出一种基于钯掺杂单壁碳纳米管(Pd-SWCNTs)的超宽带射频识别(UWB-RFID)传感器。传感器为薄型标签,由传感探头和电磁界面组成,其中传感探头为一PdSWCNTs加载的交叉指型电极(IDE);电磁界面由天线、微带线和终端负载组成。Pd-SWCNTs感知瓦斯浓度,引起IDE电流的变化,形成带隙幅度调制和带隙频率调制两种识别模式。当瓦斯浓度从0×10-6增加到100×10-6,基于带隙调幅调制的识别灵敏度为-9.32 d B;而基于带隙调频调制的识别灵敏度为-11.30 d B。
基金supported by the National Key Project on Basic Research(Grant No.2011CB935904)the National Natural Science Foundation of China(Grant No.21171163,91127020)NSF for Distinguished Young Scholars of Fujian Province(Grant No.2013J06006)
文摘A new SnO2-Fe2O3/SWCNTs（single-walled carbon nanotubes） ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles（NPs） were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction（XRD）,transmission electron microscope（TEM） and energy dispersive X-ray spectroscopy（EDX）.Due to the synergistic effect of different components,the as synthesized SnO2-Fe2O3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g-1 which could be maintained after 50 cycles at 200 mA·g-1.Even at a high rate of2000 mA·g-1,the capacity was still remained at 656 mAh·g-1.
基金Supported by Deanship of Scientific Research,Northern Border University under Grant No.SCI-2018-3-9-F-7614,KSA
文摘This work aims to study magnetohydrodynamic flow through a circular cylinder in a horizontal position of SWCNTs in blood as a base fluid in the existence of non-linear thermal radiation and heat source/sink.Three kinds of nanoparticles shapes are considered.The study is employed the finite element technique to explore and enhance the influences of essential parameters on temperature profiles and is debated the heat transport within blood injects with SWCNTs and exposes to electromagnetic radiation.The treatment with thermal analysis and heat transfer rate being a better substitute more than surgery and chemotherapy for cancer therapy.Utilizing of nanoparticles thermal features is a mounting area of nanomedicine field because of the probable for purposeful demolition of cancer cells.This remedy is relied on many parameters,including nanofluid thermal conductivity,nanoparticles volume fraction,thermal radiation and power and heat source.The numerical solutions for flow and heat transfer features are assessed for diverse governing parameters values.The obtained results are substantiated against the relevant numerical results in the published researches.Results show that both flow velocity and temperature increase for larger values of thermal radiation,heat source and SWCNTs volume fraction with lamina and cylinder shapes.Also,spherical shape of SWCNTs occurs high disturbances in velocity and temperature distribution in the case of cooled cylinder.
文摘电控离子交换技术(electrochemically switched ion exchange,ESIX)是将电活性离子交换材料(EXIMs)沉积或涂覆在导电基底上,通过电化学控制导电基底上活性材料氧化还原状态实现目标离子置入与释放,从而实现离子的分离。该技术具有痕量提取、无二次污染、速率可控、高选择性等优点。通过共沉淀法制备Ni Fe Mn LDH,并将其与碳纳米管(CNTs)、聚偏二氟乙烯(PVDF)混合涂覆到石墨板上,制得NiFeMn LDH/CNTs/PVDF膜电极。NiFeMn LDH层板上具有丰富的羟基官能团,可与W(Ⅵ)发生羟基配位;层间的阴离子与W(Ⅵ)进行离子交换,可为W(Ⅵ)提供丰富的活性位点。在ESIX系统中,膜电极对W(Ⅵ)的吸附容量可达122.10 mg·g^(-1),且W(Ⅵ)与Mo(Ⅵ)、Cl^(-)、■分离因子(■)分别为1.25、19.60、35.80,实现了W(Ⅵ)选择性分离。此外,该膜电极具有优异的循环稳定性,为钨的高效分离提供了新的方向。
