The aging-hardening kinetics of powder metallurgy processed 2014Al alloy and its composite have been studied. The existence of n-SiC particulates leads to the increase of peak hardness. Interestingly, the aginghardeni...The aging-hardening kinetics of powder metallurgy processed 2014Al alloy and its composite have been studied. The existence of n-SiC particulates leads to the increase of peak hardness. Interestingly, the aginghardening peak of the composite takes place at earlier time than that of the unreinforced alloy. Transmission electron microscopy（TEM） studies indicated that the major precipitation phases are Al_5Cu_2Mn_3 and θ′（Al_2Cu）. Besides, Ω phase appeared in both specimens at peak hardening condition, which has been rarely observed previously in aluminum metal matrix composites without Ag. Accelerated aging kinetics and increased peak hardness may be attributed to the higher dislocation density resulted from the mismatch of coefficients of thermal expansion between n-SiC and 2014Al matrix. The results are beneficial to fabricating high performance composites for the application in automobile field such as pistons, driveshaft tubes, brake rotors, bicycle frames, railroad brakes.展开更多
The demand for sustainable and stretchable thin-film printed batteries for bioelectronics,wearables,and e-textiles is rapidly increasing.Recently,we developed a fully 3D-printed soft-matter thin-film Ga-Ag_(2)O batter...The demand for sustainable and stretchable thin-film printed batteries for bioelectronics,wearables,and e-textiles is rapidly increasing.Recently,we developed a fully 3D-printed soft-matter thin-film Ga-Ag_(2)O battery with 3R characteristics:resilient to mechanical strain,repairable after damage,and recyclable.This battery achieved a record-breaking areal capacity of 26.37 mAh cm-2,increasing to 30.32 mAh cm^(-2) after 10 cycles under 100%strain.This performance stems from the synergistic effects of gallium’s liquid metal properties and the styrene-isoprene-styrene polymer in the anode.Gallium’s high specific capacity(1153.2 mAh g^(-1)),deformability,and self-healing abilities,supported by its supercooled liquid phase,significantly enhance the battery’s resilience and efficiency.However,the cathode’s lower theoretical capacity,due to Ag_(2)O(231.31 mAh g^(-1)),remains a limitation.Traditional Ag_(2)O-carbon black-styrene-isoprene-styrene cathodes experience rapid capacity decay as only the surface area of the active materials interacts with the electrolyte.To overcome this,we designed a carbon-filled Ag_(2)O foam electrode using a sacrificial sugar template,increasing the effective surface area.This optimization enhanced ion-exchange efficiency,specific capacity,and cyclability,achieving a specific capacity of 221.16 mAh g^(-1).Consequently,the Ga-Ag_(2)O stretchable battery attained a record areal capacity of 40.91 mAh cm^(-2)—double that of nonfoam electrodes—and exhibited fivefold improved charge-discharge cycles.Using ultrastretchable Ag-EGaIn-styrene-isoprene-styrene and carbon black-styrene-isoprene-styrene current collectors,the battery’s specific capacity increased by 33%under 50%strain.Integrated into a soft-matter smart wristband for temperature monitoring,the battery demonstrated its promise for wearable electronics.展开更多
Pd/Ag/α-Al2O3 composite membranes were prepared by sequential electroless plating technique. The prepared membranes were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy disper...Pd/Ag/α-Al2O3 composite membranes were prepared by sequential electroless plating technique. The prepared membranes were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy, and inductively coupled plasma atomic emission spectroscopy techniques （ICP-AES）. Effects of annealing time, Ag content, and air treatment on the hydrogen permeation flux and morphology of the alloys were investigated. The results of the investigation showed that the prepared type of tube had a good potential as substrate for membrane preparation. In addition, a uniform defect-free alloy was prepared by annealing at 550 ℃ in H2 atmosphere. The permeation results showed an increase in H2 permeation flux by increasing the Ag content and the annealing time. In addition, the air treatment of the prepared membranes at 400 ℃ for 1 h changed the morphology of the alloy and substantially enhanced the hydrogen flux.展开更多
W-30 wt%Cu and TiC-50 wt%Ag were successfully synthesized by a novel simplified pretreatment followed by electroless plating. The 0 wt% TiC, 0.5 wt% TiC, and 0.5 wt%TiC-0.5 wt%Ag composite powders were added to W-30 w...W-30 wt%Cu and TiC-50 wt%Ag were successfully synthesized by a novel simplified pretreatment followed by electroless plating. The 0 wt% TiC, 0.5 wt% TiC, and 0.5 wt%TiC-0.5 wt%Ag composite powders were added to W-30 wt%Cu composite powders by blending, and then reduced. The reduced W-30 Cu, W-30 Cu/0.5 TiC, and W-30 Cu-0.5 Ag/0.5 TiC composite powders were then compacted and sintered at 1 300 ℃ in protective hydrogen for 60 min. The phase and morphology of the composite powders and materials were analyzed using X-ray diffraction and field emission scanning electron microscopy. The relative density, electrical conductivity, and hardness of the sintered samples were examined. Results showed that W-30 Cu and TiC-Ag composite powders with uniform structure were obtained using simplified pretreatment followed by electroless plating. The addition of TiC particles can significantly increase the compressive strength and hardness of the W-30 Cu composite material but decrease the electrical conductivity. Next, 0.5 wt% Ag was added to prepare W-30 Cu-0.5 Ag/TiC composites with excellent electrical conductivity. The electrical conductivity of these composites(61.2%) is higher than that in the national standard(the imaginary line denotes electrical conductivity of GB IACS 42%) of 45.7%.展开更多
Silver as a highly conductive metal is usually doped in YBa2Cu3O7-x superconductor bulks to improve critical current density of YBa2Cu3O7-x superconductor.The valuable metal elements silver,yttrium,barium and copper i...Silver as a highly conductive metal is usually doped in YBa2Cu3O7-x superconductor bulks to improve critical current density of YBa2Cu3O7-x superconductor.The valuable metal elements silver,yttrium,barium and copper in waste YBa2Cu3O7-x/Ag composite superconductor bulks were recovered,respectively.Silver was recovered with process at first,the waste was dissolved by nitric acid and silver chloride was precipitated by adding chloride acid,then silver pig was obtained by melting silver chloride together with sodium carbonate at 1 000℃.The effective factors on recovery ratio and purity of silver were studied.The chemical analysis proves that the purity of silver ingot is 95.86%.The recovery ratio of silver is calculated to be 92.56%.The loss of silver may be due to the loss of silver chloride during filtering and the volatilization of silver when silver chloride and sodium carbonate are smelted at high temperature.For other three metal elements,Y3 +,Ba 2+and Cu 2+,in the surplus waste liquid after recovering silver, they were separated with the sequence of barium,copper and then yttrium step by step.First,sulfate acid was used to precipitate barium sulfate.Then,sodium sulfide was added to the surplus solution so that copper could be separated as copper sulfide.During this separation procedure,it was important to control the pH value to be 1-2.After that,oxalic acid was added into the surplus solution to obtain yttrium oxalate.Finally,yttrium oxide was formed by burning yttrium oxalate.The XRD results indicate that the final products are all single-phase compounds as BaSO4,CuS and Y2O3,respectively.展开更多
The atom (Ag,Cu) diffusion behavior and the effect of technology on the interface of rolled Ag/Cu composite contact were investigated. The concentration of Ag and Cu atoms near the interface was determined with electr...The atom (Ag,Cu) diffusion behavior and the effect of technology on the interface of rolled Ag/Cu composite contact were investigated. The concentration of Ag and Cu atoms near the interface was determined with electron probe. The bonding strength of composite interface was tested and the fracture in tensile sample was observed by SEM. The results show that there was inter diffusion of Ag and Cu atoms on the interface, which formed compact layer with high bonding strength of 98 MPa. The practical application proved that the Ag/Cu composite interface is reliable.展开更多
Ag nanoparticles embedded in soda-lime silicate glass were fabricated by ion-exchange and subsequently annealing method. Effects of annealing duration on the optical nonlinearity and ultrafast dynamics of Ag nanoparti...Ag nanoparticles embedded in soda-lime silicate glass were fabricated by ion-exchange and subsequently annealing method. Effects of annealing duration on the optical nonlinearity and ultrafast dynamics of Ag nanoparticles in glass were investigated by z-scan technique and pump-probe technique. The results indicate that the third-order optical nonlinearity increases with extending the annealing time, the fast decay process with lifetime of a few picoseconds is attributed to thermal equilibrium process of hot electrons and the energy transfer to lattices by interaction with phonons in the formed Ag nanoparticles, while the slow decay in more than one hundred picoseconds corresponds to the subsequent cooling process by a thermal diffusion from the Ag nanoparticle to the host matrix via the phonon-medium interaction. The fast decay process is accelerated with extending the annealing time.展开更多
We present a new and practical approach for preparing submicro-textured silver and aluminum （Ag/Al） double-structured layers at low substrate temperatures. The surface texturing of silver and aluminum double-structu...We present a new and practical approach for preparing submicro-textured silver and aluminum （Ag/Al） double-structured layers at low substrate temperatures. The surface texturing of silver and aluminum double-structured layers was performed by increasing the deposition temperature of the Al layers to 270℃. The highly submicro-textured silver and aluminum double-structured layers were prepared by thermal evaporation on quartz glasses and their surface microstructure, light scattering properties, and thermal stability were investigated. Results showed that the highly submicro-textured Ag/Al composite films prepared at low substrate temperatures used as back reflectors not only can enhance the light scattering and have good thermal stability, but also have good adhesion properties. In addition, their fabrication is low cost and readily carried out.展开更多
Silver nanoclusters（NCs） embedded in soda-lime glass was synthesized by the electric fieldassisted diffusion（EFAD） and successive annealing. The samples were characterized by UV-Vis absorption spectroscopy, photol...Silver nanoclusters（NCs） embedded in soda-lime glass was synthesized by the electric fieldassisted diffusion（EFAD） and successive annealing. The samples were characterized by UV-Vis absorption spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy（XPS）, and lifetime measurements. The experimental results show that the growth of silver clusters is favored by the annealing temperature and dwell time. The as-diffused and annealed glass samples show photoluminescence around 550 nm under UV excitation, which can be associated with the presence of L-center and Ag3~＋ cluster. And the increasing of the annealing temperature and dwell time results in an appearance of the SPR peak and the decreasing of the luminescence intensities because the Ag3~＋ clusters grow up into the Ag nanoparticles.展开更多
Due to their outstanding electrical contact properties,Cd-containing silver-matrix electrical contact materials can meet the requirements of high stability and long life for military defense and aerospace applications...Due to their outstanding electrical contact properties,Cd-containing silver-matrix electrical contact materials can meet the requirements of high stability and long life for military defense and aerospace applications.In order to further reduce the Cd content under the premise of meeting the high-performance requirements,in this study,high-purity intermediate Ti_(2)Cd powder of MAX phase(Ti_(2)CdC)was synthesized with a pressureless technique and then applied to reinforce the Ag matrix.The Cd content of the as-prepared Ag/Ti_(2)Cd composites was actually reduced by 38.31%compared with conventional Ag/CdO material.Based on the systematic study of the effect of heat treatment temperature on the physical phase,morphology,interface and comprehensive physical properties of Ag/Ti_(2)Cd composites,the preferred samples(heat treated at 400°C for 1 h)showed high density(97.77%),low resistivity(2.34μΩ·cm),moderate hardness(90.8HV),high tensile strength(189.9 MPa),and exhibited good electrical contact performance after 40000 cycles of arc discharging under severe conditions(DC 28 V/20 A).The results of microscopic morphological evolution,phase change and elemental distribution of the electrical contact surface show that the combination of high stability of Ti_(2)Cd reinforcing phase,good interfacial bonding with Ag matrix and improved melt pool viscosity in the primary stage of arc erosion,results in low and stable contact resistance(average value 13.20 mΩ)and welding force(average value 0.6 N),low fluctuation of static force(2.2-2.5 N).The decomposition and absorption energy of Ti_(2)Cd and the arc extinguishing effect of Cd vapor are the main reasons for the stable arcing energy and arcing time of electric contacts in the late stage of arc erosion.展开更多
Low-cost Cu/Ag composite sheathed Ba_(0.6)K_(α)Fe_(2)As_(2)superconducting tapes have been the focus of considerable research interest in terms of superconducting properties and performance improvement.The K-doping c...Low-cost Cu/Ag composite sheathed Ba_(0.6)K_(α)Fe_(2)As_(2)superconducting tapes have been the focus of considerable research interest in terms of superconducting properties and performance improvement.The K-doping content has a great influence on the transport critical current density(J_(c))of Cu/Ag composite sheathed tapes.This study analyzes the evolution occurring within the micro-composition and the mechanism affecting the transport J_(c) in Ba_(0.6)K_(α)Fe_(2)As_(2)(0.42≤α≤0.54)raw material,by modulating the ratio of K.It has been demonstrated that both extremes of K content,namely an insufficient or excessive amount,have an adverse effect on phase purity of the powders.Consequently,this has a direct impact on the transport J_(c) of tapes.Cu/Ag tapes fabricated using a precursor powder with an optimal K ratio α∼0.464 exhibited the highest performance,with a J_(c) of 5.8×10^(4) A cm^(−2) at 10 T and 4.2 K.The optimized Cu/Ag composite tapes have been found to have superior advantages for high-field applications.展开更多
Li metal is the most attractive and promising anode material for next-generation high-energy batteries.However,uncontrolled Li dendrite growth during cycling remains a highly challenging drawback.To solve this problem...Li metal is the most attractive and promising anode material for next-generation high-energy batteries.However,uncontrolled Li dendrite growth during cycling remains a highly challenging drawback.To solve this problem,silver-coated graphene(Ag/GH)was prepared via a simple liquid-phase reduction method.The effect of Ag/GH on Li deposition behavior was investigated by adjusting the dispersion of Ag nanoparticles(Ag NPs).Subsequently,a composite electrode was fabricated via uniform deposition of metallic Li on Ag/GH.Ag was used as a lithiophilic nucleating agent to ensure uniform deposition of Li and inhibit the growth of Li dendrites on the anode.The prepared composite anode showed a significantly improved performance compared to the unmodified electrode.The symmetric cell comprising this composite electrode exhibited a stable cycling performance with a low hysteresis of~40 mV and a lifetime of>2000 h at a current density of 0.5 mA·cm^(-2).Meanwhile,the discharge capacity reached 0.5 mAh·cm^(-2).In addition,Ag/GH was found to be amenable to large-scale synthesis.Thus,the composite Ag/GH anode exhibited improved performance and the preparation method showed significant potential for application in the manufacture of Li metal batteries.展开更多
The uncontrolled dendrite growth and shuttle effect of polysulfides have hindered the practical application of lith-ium-sulfur(Li-S)batteries.Herein,a metal-organic framework-derived Ag/C core-shell composite integrat...The uncontrolled dendrite growth and shuttle effect of polysulfides have hindered the practical application of lith-ium-sulfur(Li-S)batteries.Herein,a metal-organic framework-derived Ag/C core-shell composite integrated with a carbon nanofiber film(Ag/C@CNF)is developed to address these issues in Li-S batteries.The Ag/C core-shell structure design endows the CNF skeleton with enhanced electrical conductivity,electrocatalysis performance toward polysulfides conversion,and lithium nucleation.When served as a freestanding bifunctional host in Li-S batteries,the Ag/C@CNF composite regulates the Li and sulfur electrochemical processes by guiding the uniform Li deposition with mitigated dendrite growth and at the same time accelerating the polysulfides conversion.The assembled Li-S full battery delivers a considerable capacity of 650 mAh g^(-1),an ultralong cyclability with an attenuation rate as low as 0.02%per cycle for 1000 cycles at 5 C,and excellent rate performances at increased sulfur loading up to 7.6 mg cm^(-2)under lean electrolyte condition.展开更多
The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately ...The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.展开更多
The development of multifunctional composites with desirable electromagnetic wave absorption and antibacterial performance for the medical field has aroused wide interest.In this work,SioC/Ag composites were successfu...The development of multifunctional composites with desirable electromagnetic wave absorption and antibacterial performance for the medical field has aroused wide interest.In this work,SioC/Ag composites were successfully fabricated via the liquid-phase method.When the filler content of SiOC/Ag-3 is 40wt%,SiOC/Ag-3exhibits excellent electromagnetic wave absorption performance,achieving a minimum reflection loss(RL_(min))value of-58.03 dB with a matching thickness of only 2.82 mm.The superior electromagnetic wave absorption performance is attributed to(i)multiple reflections,(ii)conductive loss,and(iii)interfacial polarization loss.In addition,the radar cross-section(RCS)simulation indicates that all RCS values of the perfect electric conductor(PEC)with the SioC/Ag-3 coating are below-20 dB-m^(2)across the incident angle range from-60°to 60,indicating strong radar stealth performance.Moreover,SiOC/Ag composites also achieve excellent antibacterial ability against E.coli and S.aureus through the generation of reactive oxygen species(ROS)under visible light irradiation.This work provides new insights into the design and development of bifunctional composites with electromagnetic wave absorption and antibacterial performancefor application in medical devices.展开更多
We have investigated the phase equilibria in (RE)BaCuO/Ag systems, the influence of Ag on the processing of (RE)BaCuO/Ag composites and the resulting properties. YBaCuO/Ag composites have been grown by the modified me...We have investigated the phase equilibria in (RE)BaCuO/Ag systems, the influence of Ag on the processing of (RE)BaCuO/Ag composites and the resulting properties. YBaCuO/Ag composites have been grown by the modified melt crystallization process with YBa2Cu3O7, Y2O3, Pt and Ag2O in the precursor. The improved strength of the YBaCuO/Ag composites compared with the conventional YBaCuO bulk material permitted us to magnetize these materials to achieve trapped fields up to 16 T (at 24 K) in the gap of a mini-magnet. The investigation of the microstructure revealed a remarkable increase of the spacing between micro-cracks especially of those perpendicular to a/b-planes when 12wt%Ag was added. In the case of SmBaCuO/Ag composites, Ag has a strong influence on processing and causes interactions between RE123 seeds and the sample. We show the growth of single-grain SmBaCuO/Ag composites in air and discuss the influence of post-annealing on increasing Tc and Jc. Furthermore, YBaCuO/Ag composites have been shown to be appropriate materials used as a solder to join large single grains to large arrays or to 'repair' grain boundaries in arrays grown by a multiseeding technique.展开更多
Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag ...Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag from Ag+ precursors. In situ energy dispersive X-ray diffraction (EDXRD) monitoring showed that the hydrothermal formation kinetics of Bi2WO6 in the presence of EG was significantly slowed down due to its very high viscosity. The photocatalytic activities of Ag/Bi2WO6 composites were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation. The photocatalytic activity of Bi2WO6 is strongly influenced by the Ag loading. The enhanced catalytic activity of the composites is based on the cooperative effects of plasmon absorption band and separation of photogenerated electron-hole pairs.展开更多
A novel Ag3PO4-AgBr-PTh composite loaded on Na2SiO3 was synthesized for enhanced visible-light photocatalytic activity. The photocatalyUc activity of the samples was evaluated by photodegrading rhodamine B （RhB） und...A novel Ag3PO4-AgBr-PTh composite loaded on Na2SiO3 was synthesized for enhanced visible-light photocatalytic activity. The photocatalyUc activity of the samples was evaluated by photodegrading rhodamine B （RhB） under visible light irradiation. The main reactive species and possible photocatalytic mechanism were also discussed. As a result, the Ag3PO4-AgBr-PTh composite loaded on Na2SiO3 exhibited enhanced photocatalytic activity for RhB compared with Ag3PO4 under visible-light irradiation. Additionally, it was demonstrated that the hole （h＋） and superoxide radical （·O2-） were the major reactive species involving in the RhB degradation. PTh played vital role for the enhanced photocatalytic activity of Ag3PO4-AgBr-PTh-Na2SiO3 composite, which offered an electron transfer expressway and accelerated the transfer of the electrons from the CB of AgBr into Ag3PO4. This work could provide a new perspective for the synthesis of Ag3PO4-based composites and the improvement of photocatalytic activity of Ag3PO4.展开更多
基金Financial support by the National Basic Research Program of China(“973”Program,No.2012CB619600)the National Natural Science Foundation of China(No.51474111)+2 种基金the Science and Technology Development Project of Jilin Province(No.20160519002JH)support came from the Fundamental Research Funds for the Central Universities(JCKY-QKJC02)the Chang Bai Mountain Scholars Program(2013014)
文摘The aging-hardening kinetics of powder metallurgy processed 2014Al alloy and its composite have been studied. The existence of n-SiC particulates leads to the increase of peak hardness. Interestingly, the aginghardening peak of the composite takes place at earlier time than that of the unreinforced alloy. Transmission electron microscopy（TEM） studies indicated that the major precipitation phases are Al_5Cu_2Mn_3 and θ′（Al_2Cu）. Besides, Ω phase appeared in both specimens at peak hardening condition, which has been rarely observed previously in aluminum metal matrix composites without Ag. Accelerated aging kinetics and increased peak hardness may be attributed to the higher dislocation density resulted from the mismatch of coefficients of thermal expansion between n-SiC and 2014Al matrix. The results are beneficial to fabricating high performance composites for the application in automobile field such as pistons, driveshaft tubes, brake rotors, bicycle frames, railroad brakes.
基金supported by the European Research Council,ERC project Liquid3D,grant number 101045072supported by the Foundation of Science and Technology(FCT)of Portugal through the CMU-Portugal project WoW(Reference No:45913).
文摘The demand for sustainable and stretchable thin-film printed batteries for bioelectronics,wearables,and e-textiles is rapidly increasing.Recently,we developed a fully 3D-printed soft-matter thin-film Ga-Ag_(2)O battery with 3R characteristics:resilient to mechanical strain,repairable after damage,and recyclable.This battery achieved a record-breaking areal capacity of 26.37 mAh cm-2,increasing to 30.32 mAh cm^(-2) after 10 cycles under 100%strain.This performance stems from the synergistic effects of gallium’s liquid metal properties and the styrene-isoprene-styrene polymer in the anode.Gallium’s high specific capacity(1153.2 mAh g^(-1)),deformability,and self-healing abilities,supported by its supercooled liquid phase,significantly enhance the battery’s resilience and efficiency.However,the cathode’s lower theoretical capacity,due to Ag_(2)O(231.31 mAh g^(-1)),remains a limitation.Traditional Ag_(2)O-carbon black-styrene-isoprene-styrene cathodes experience rapid capacity decay as only the surface area of the active materials interacts with the electrolyte.To overcome this,we designed a carbon-filled Ag_(2)O foam electrode using a sacrificial sugar template,increasing the effective surface area.This optimization enhanced ion-exchange efficiency,specific capacity,and cyclability,achieving a specific capacity of 221.16 mAh g^(-1).Consequently,the Ga-Ag_(2)O stretchable battery attained a record areal capacity of 40.91 mAh cm^(-2)—double that of nonfoam electrodes—and exhibited fivefold improved charge-discharge cycles.Using ultrastretchable Ag-EGaIn-styrene-isoprene-styrene and carbon black-styrene-isoprene-styrene current collectors,the battery’s specific capacity increased by 33%under 50%strain.Integrated into a soft-matter smart wristband for temperature monitoring,the battery demonstrated its promise for wearable electronics.
文摘Pd/Ag/α-Al2O3 composite membranes were prepared by sequential electroless plating technique. The prepared membranes were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy, and inductively coupled plasma atomic emission spectroscopy techniques （ICP-AES）. Effects of annealing time, Ag content, and air treatment on the hydrogen permeation flux and morphology of the alloys were investigated. The results of the investigation showed that the prepared type of tube had a good potential as substrate for membrane preparation. In addition, a uniform defect-free alloy was prepared by annealing at 550 ℃ in H2 atmosphere. The permeation results showed an increase in H2 permeation flux by increasing the Ag content and the annealing time. In addition, the air treatment of the prepared membranes at 400 ℃ for 1 h changed the morphology of the alloy and substantially enhanced the hydrogen flux.
基金Funded by the National Magnetic Confinement Fusion Program(No.2014GB121001)
文摘W-30 wt%Cu and TiC-50 wt%Ag were successfully synthesized by a novel simplified pretreatment followed by electroless plating. The 0 wt% TiC, 0.5 wt% TiC, and 0.5 wt%TiC-0.5 wt%Ag composite powders were added to W-30 wt%Cu composite powders by blending, and then reduced. The reduced W-30 Cu, W-30 Cu/0.5 TiC, and W-30 Cu-0.5 Ag/0.5 TiC composite powders were then compacted and sintered at 1 300 ℃ in protective hydrogen for 60 min. The phase and morphology of the composite powders and materials were analyzed using X-ray diffraction and field emission scanning electron microscopy. The relative density, electrical conductivity, and hardness of the sintered samples were examined. Results showed that W-30 Cu and TiC-Ag composite powders with uniform structure were obtained using simplified pretreatment followed by electroless plating. The addition of TiC particles can significantly increase the compressive strength and hardness of the W-30 Cu composite material but decrease the electrical conductivity. Next, 0.5 wt% Ag was added to prepare W-30 Cu-0.5 Ag/TiC composites with excellent electrical conductivity. The electrical conductivity of these composites(61.2%) is higher than that in the national standard(the imaginary line denotes electrical conductivity of GB IACS 42%) of 45.7%.
基金Project(50702012)supported by the National Natural Science Foundation of ChinaProject(20060145030)supported by Doctoral Foundation of Chinese Education Ministry
文摘Silver as a highly conductive metal is usually doped in YBa2Cu3O7-x superconductor bulks to improve critical current density of YBa2Cu3O7-x superconductor.The valuable metal elements silver,yttrium,barium and copper in waste YBa2Cu3O7-x/Ag composite superconductor bulks were recovered,respectively.Silver was recovered with process at first,the waste was dissolved by nitric acid and silver chloride was precipitated by adding chloride acid,then silver pig was obtained by melting silver chloride together with sodium carbonate at 1 000℃.The effective factors on recovery ratio and purity of silver were studied.The chemical analysis proves that the purity of silver ingot is 95.86%.The recovery ratio of silver is calculated to be 92.56%.The loss of silver may be due to the loss of silver chloride during filtering and the volatilization of silver when silver chloride and sodium carbonate are smelted at high temperature.For other three metal elements,Y3 +,Ba 2+and Cu 2+,in the surplus waste liquid after recovering silver, they were separated with the sequence of barium,copper and then yttrium step by step.First,sulfate acid was used to precipitate barium sulfate.Then,sodium sulfide was added to the surplus solution so that copper could be separated as copper sulfide.During this separation procedure,it was important to control the pH value to be 1-2.After that,oxalic acid was added into the surplus solution to obtain yttrium oxalate.Finally,yttrium oxide was formed by burning yttrium oxalate.The XRD results indicate that the final products are all single-phase compounds as BaSO4,CuS and Y2O3,respectively.
文摘The atom (Ag,Cu) diffusion behavior and the effect of technology on the interface of rolled Ag/Cu composite contact were investigated. The concentration of Ag and Cu atoms near the interface was determined with electron probe. The bonding strength of composite interface was tested and the fracture in tensile sample was observed by SEM. The results show that there was inter diffusion of Ag and Cu atoms on the interface, which formed compact layer with high bonding strength of 98 MPa. The practical application proved that the Ag/Cu composite interface is reliable.
基金Funded by the National Natural Science Foundation of China (No.50672069)Key Item for Basic Research of Shanghai (No.05JC14058)
文摘Ag nanoparticles embedded in soda-lime silicate glass were fabricated by ion-exchange and subsequently annealing method. Effects of annealing duration on the optical nonlinearity and ultrafast dynamics of Ag nanoparticles in glass were investigated by z-scan technique and pump-probe technique. The results indicate that the third-order optical nonlinearity increases with extending the annealing time, the fast decay process with lifetime of a few picoseconds is attributed to thermal equilibrium process of hot electrons and the energy transfer to lattices by interaction with phonons in the formed Ag nanoparticles, while the slow decay in more than one hundred picoseconds corresponds to the subsequent cooling process by a thermal diffusion from the Ag nanoparticle to the host matrix via the phonon-medium interaction. The fast decay process is accelerated with extending the annealing time.
基金the National Natural Science Foundation of China(Grant No.60977028)the Key Project Foundation of Shanghai,China(Grant No.09JC1413800)
文摘We present a new and practical approach for preparing submicro-textured silver and aluminum （Ag/Al） double-structured layers at low substrate temperatures. The surface texturing of silver and aluminum double-structured layers was performed by increasing the deposition temperature of the Al layers to 270℃. The highly submicro-textured silver and aluminum double-structured layers were prepared by thermal evaporation on quartz glasses and their surface microstructure, light scattering properties, and thermal stability were investigated. Results showed that the highly submicro-textured Ag/Al composite films prepared at low substrate temperatures used as back reflectors not only can enhance the light scattering and have good thermal stability, but also have good adhesion properties. In addition, their fabrication is low cost and readily carried out.
基金Funded by the Shanghai Science and Technology Committee(12nm0504700)
文摘Silver nanoclusters（NCs） embedded in soda-lime glass was synthesized by the electric fieldassisted diffusion（EFAD） and successive annealing. The samples were characterized by UV-Vis absorption spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy（XPS）, and lifetime measurements. The experimental results show that the growth of silver clusters is favored by the annealing temperature and dwell time. The as-diffused and annealed glass samples show photoluminescence around 550 nm under UV excitation, which can be associated with the presence of L-center and Ag3~＋ cluster. And the increasing of the annealing temperature and dwell time results in an appearance of the SPR peak and the decreasing of the luminescence intensities because the Ag3~＋ clusters grow up into the Ag nanoparticles.
基金This work was financially supported by the National Natural Science Foundation of China(52101064)Jiangsu Planned Projects for Postdoctoral Research Funds(2020Z158)Industry-University-Research Cooperation Projects(RH2000002728,RH2000002332,RH2100000263).
文摘Due to their outstanding electrical contact properties,Cd-containing silver-matrix electrical contact materials can meet the requirements of high stability and long life for military defense and aerospace applications.In order to further reduce the Cd content under the premise of meeting the high-performance requirements,in this study,high-purity intermediate Ti_(2)Cd powder of MAX phase(Ti_(2)CdC)was synthesized with a pressureless technique and then applied to reinforce the Ag matrix.The Cd content of the as-prepared Ag/Ti_(2)Cd composites was actually reduced by 38.31%compared with conventional Ag/CdO material.Based on the systematic study of the effect of heat treatment temperature on the physical phase,morphology,interface and comprehensive physical properties of Ag/Ti_(2)Cd composites,the preferred samples(heat treated at 400°C for 1 h)showed high density(97.77%),low resistivity(2.34μΩ·cm),moderate hardness(90.8HV),high tensile strength(189.9 MPa),and exhibited good electrical contact performance after 40000 cycles of arc discharging under severe conditions(DC 28 V/20 A).The results of microscopic morphological evolution,phase change and elemental distribution of the electrical contact surface show that the combination of high stability of Ti_(2)Cd reinforcing phase,good interfacial bonding with Ag matrix and improved melt pool viscosity in the primary stage of arc erosion,results in low and stable contact resistance(average value 13.20 mΩ)and welding force(average value 0.6 N),low fluctuation of static force(2.2-2.5 N).The decomposition and absorption energy of Ti_(2)Cd and the arc extinguishing effect of Cd vapor are the main reasons for the stable arcing energy and arcing time of electric contacts in the late stage of arc erosion.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0704200)the National Natural Science Foundation of China(Grant Nos.52377032 and 52377033)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB25000000)the International Partnership Program of Chinese Academy of Sciences(Grant No.116GJHZ2023005MI).
文摘Low-cost Cu/Ag composite sheathed Ba_(0.6)K_(α)Fe_(2)As_(2)superconducting tapes have been the focus of considerable research interest in terms of superconducting properties and performance improvement.The K-doping content has a great influence on the transport critical current density(J_(c))of Cu/Ag composite sheathed tapes.This study analyzes the evolution occurring within the micro-composition and the mechanism affecting the transport J_(c) in Ba_(0.6)K_(α)Fe_(2)As_(2)(0.42≤α≤0.54)raw material,by modulating the ratio of K.It has been demonstrated that both extremes of K content,namely an insufficient or excessive amount,have an adverse effect on phase purity of the powders.Consequently,this has a direct impact on the transport J_(c) of tapes.Cu/Ag tapes fabricated using a precursor powder with an optimal K ratio α∼0.464 exhibited the highest performance,with a J_(c) of 5.8×10^(4) A cm^(−2) at 10 T and 4.2 K.The optimized Cu/Ag composite tapes have been found to have superior advantages for high-field applications.
基金financially supported by the National Natural Science Foundation of China(No.51972224)China Postdoctoral Science Foundation(No.2019M661014)。
文摘Li metal is the most attractive and promising anode material for next-generation high-energy batteries.However,uncontrolled Li dendrite growth during cycling remains a highly challenging drawback.To solve this problem,silver-coated graphene(Ag/GH)was prepared via a simple liquid-phase reduction method.The effect of Ag/GH on Li deposition behavior was investigated by adjusting the dispersion of Ag nanoparticles(Ag NPs).Subsequently,a composite electrode was fabricated via uniform deposition of metallic Li on Ag/GH.Ag was used as a lithiophilic nucleating agent to ensure uniform deposition of Li and inhibit the growth of Li dendrites on the anode.The prepared composite anode showed a significantly improved performance compared to the unmodified electrode.The symmetric cell comprising this composite electrode exhibited a stable cycling performance with a low hysteresis of~40 mV and a lifetime of>2000 h at a current density of 0.5 mA·cm^(-2).Meanwhile,the discharge capacity reached 0.5 mAh·cm^(-2).In addition,Ag/GH was found to be amenable to large-scale synthesis.Thus,the composite Ag/GH anode exhibited improved performance and the preparation method showed significant potential for application in the manufacture of Li metal batteries.
基金sponsorship from Outstanding Young Talents Project of Hebei High Education Institutions(BJ2021020)National Natural Science Foundation of China(No.22278109).
文摘The uncontrolled dendrite growth and shuttle effect of polysulfides have hindered the practical application of lith-ium-sulfur(Li-S)batteries.Herein,a metal-organic framework-derived Ag/C core-shell composite integrated with a carbon nanofiber film(Ag/C@CNF)is developed to address these issues in Li-S batteries.The Ag/C core-shell structure design endows the CNF skeleton with enhanced electrical conductivity,electrocatalysis performance toward polysulfides conversion,and lithium nucleation.When served as a freestanding bifunctional host in Li-S batteries,the Ag/C@CNF composite regulates the Li and sulfur electrochemical processes by guiding the uniform Li deposition with mitigated dendrite growth and at the same time accelerating the polysulfides conversion.The assembled Li-S full battery delivers a considerable capacity of 650 mAh g^(-1),an ultralong cyclability with an attenuation rate as low as 0.02%per cycle for 1000 cycles at 5 C,and excellent rate performances at increased sulfur loading up to 7.6 mg cm^(-2)under lean electrolyte condition.
基金supported by the Natural Science Foundation of Chongqing City(Grant Nos.CSTB2022NSCQ-MSX0751 and cstc2021jcyj-msxmX0500)the Education Department Project of Jilin Province(Grant No.JJKH20220726KJ)+1 种基金the Science and Technology Department Project of Jilin Province(Grant No.20200201077JC)the National Natural Science Foundation of China(Grant No.U2141239).
文摘The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.
基金supported by the Science Foundation of Jiangxi Provincial Department of Education(No.GJ2400915)the Early Career Youth Science and Technology Talent Training Project of Jiangxi Province(No.20244BCE52206)the National Natural Science Foundation of China(No.52360018).
文摘The development of multifunctional composites with desirable electromagnetic wave absorption and antibacterial performance for the medical field has aroused wide interest.In this work,SioC/Ag composites were successfully fabricated via the liquid-phase method.When the filler content of SiOC/Ag-3 is 40wt%,SiOC/Ag-3exhibits excellent electromagnetic wave absorption performance,achieving a minimum reflection loss(RL_(min))value of-58.03 dB with a matching thickness of only 2.82 mm.The superior electromagnetic wave absorption performance is attributed to(i)multiple reflections,(ii)conductive loss,and(iii)interfacial polarization loss.In addition,the radar cross-section(RCS)simulation indicates that all RCS values of the perfect electric conductor(PEC)with the SioC/Ag-3 coating are below-20 dB-m^(2)across the incident angle range from-60°to 60,indicating strong radar stealth performance.Moreover,SiOC/Ag composites also achieve excellent antibacterial ability against E.coli and S.aureus through the generation of reactive oxygen species(ROS)under visible light irradiation.This work provides new insights into the design and development of bifunctional composites with electromagnetic wave absorption and antibacterial performancefor application in medical devices.
基金Supported by Bundesminister fur Bildung,Forschung,Wissenschaft und Technologie(BMBF,13N7677)Sachsischer Minister fur Wissenschaft und Kunst and VEGA,Slovak Academy of Science
文摘We have investigated the phase equilibria in (RE)BaCuO/Ag systems, the influence of Ag on the processing of (RE)BaCuO/Ag composites and the resulting properties. YBaCuO/Ag composites have been grown by the modified melt crystallization process with YBa2Cu3O7, Y2O3, Pt and Ag2O in the precursor. The improved strength of the YBaCuO/Ag composites compared with the conventional YBaCuO bulk material permitted us to magnetize these materials to achieve trapped fields up to 16 T (at 24 K) in the gap of a mini-magnet. The investigation of the microstructure revealed a remarkable increase of the spacing between micro-cracks especially of those perpendicular to a/b-planes when 12wt%Ag was added. In the case of SmBaCuO/Ag composites, Ag has a strong influence on processing and causes interactions between RE123 seeds and the sample. We show the growth of single-grain SmBaCuO/Ag composites in air and discuss the influence of post-annealing on increasing Tc and Jc. Furthermore, YBaCuO/Ag composites have been shown to be appropriate materials used as a solder to join large single grains to large arrays or to 'repair' grain boundaries in arrays grown by a multiseeding technique.
基金supported by the National Natural Science Foundation of China (51102245 and U1232119)the Innovative Research Team of Southwest Petroleum University (2012XJZT002)the Swiss National Science Foundation (SNSF Professorship PP0P2-133483/1)
文摘Hierarchical Ag/Bi2WO6 nanomaterials were prepared by a facile one-step hydrothermal method in mixed acetic acid and ethylene glycol (EG) medium. EG is employed as mild reducing agent for the formation of metallic Ag from Ag+ precursors. In situ energy dispersive X-ray diffraction (EDXRD) monitoring showed that the hydrothermal formation kinetics of Bi2WO6 in the presence of EG was significantly slowed down due to its very high viscosity. The photocatalytic activities of Ag/Bi2WO6 composites were evaluated by the photodegradation of methylene blue (MB) under visible light irradiation. The photocatalytic activity of Bi2WO6 is strongly influenced by the Ag loading. The enhanced catalytic activity of the composites is based on the cooperative effects of plasmon absorption band and separation of photogenerated electron-hole pairs.
文摘A novel Ag3PO4-AgBr-PTh composite loaded on Na2SiO3 was synthesized for enhanced visible-light photocatalytic activity. The photocatalyUc activity of the samples was evaluated by photodegrading rhodamine B （RhB） under visible light irradiation. The main reactive species and possible photocatalytic mechanism were also discussed. As a result, the Ag3PO4-AgBr-PTh composite loaded on Na2SiO3 exhibited enhanced photocatalytic activity for RhB compared with Ag3PO4 under visible-light irradiation. Additionally, it was demonstrated that the hole （h＋） and superoxide radical （·O2-） were the major reactive species involving in the RhB degradation. PTh played vital role for the enhanced photocatalytic activity of Ag3PO4-AgBr-PTh-Na2SiO3 composite, which offered an electron transfer expressway and accelerated the transfer of the electrons from the CB of AgBr into Ag3PO4. This work could provide a new perspective for the synthesis of Ag3PO4-based composites and the improvement of photocatalytic activity of Ag3PO4.
