The spark plasma sintering （SPS） was applied to prepare α-Si3 N4 ceramics of different densities with magnesia, silicon dioxide, alumina as the sintering aids. The mechanism of liquid phase sintering （LPS） wus d...
详细信息
The spark plasma sintering （SPS） was applied to prepare α-Si3 N4 ceramics of different densities with magnesia, silicon dioxide, alumina as the sintering aids. The mechanism of liquid phase sintering （LPS） wus discussed and the factors influencing the density of the prepared samples were analyzed. The dielectric constant of sintered samples was tested. The experimental results show that the density can be controlled from 2.48 g/ cm^3 to 3.09 g/ cm^3 while the content of the sintering aids and the sintering temperature alter and the dielectric constant is closely dependent on the density of obtained samples.
Lithium metal is a promising anode material owing to its very low electrochemical potential and ultrahigh specific ***,the growth of lithium dendrites could result in a short lifespan,low coulombic efficiency,and pote...
详细信息
Lithium metal is a promising anode material owing to its very low electrochemical potential and ultrahigh specific ***,the growth of lithium dendrites could result in a short lifespan,low coulombic efficiency,and potential safety hazards during the progress of lithium plating/*** factors drastically hinder its application in lithium metal *** review focuses on the use of three dimensional(3D)porous host frameworks to improve Li plating/stripping behaviors,accommodate the change in volume,and suppress or block lithium dendrite *** 3D porous frameworks,including the conductive carbon-based,metal-based,and lithiophilic inorganic-compound frameworks are introduced and summarized in *** particular functions,relative developments,and optimized strategies of various 3D porous frameworks for lithium deposition/dissolution behaviors are ***,the challenges and promising developments in the field of Li metal anodes will be discussed at the end of this review.
ZnO hexagonal prism crystals were synthesized from ZnO powders by microwave heating in a short time （within 20 min） without any metal catalyst or transport agent. Zinc oxide raw materials were made by evaporating fr...
详细信息
ZnO hexagonal prism crystals were synthesized from ZnO powders by microwave heating in a short time （within 20 min） without any metal catalyst or transport agent. Zinc oxide raw materials were made by evaporating from the high-temperature zone in an enclosure atmosphere and crystals were grown on the self-source substrate. The inherent asymmetry in microwave heating provides the temperature gradient for crystal growth. Substrate and temperature distribution in the oven show significant effects on the growth of the ZnO crystal. The morphologies demonstrate that these samples are pure hexagonal prism crystals with maximum 80 lain in diameter and 600 lure in length, which possess a well faceted end and side surface. X-ray diffraction （XRD） reveals that these samples are pure crystals. The photoluminescence （PL） exhibits strong ultraviolet emission at room temperature, indicating potential applications for short-wave light-emitting photonic devices.
The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulat...
详细信息
The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulate the moldingprocess, and the simulation results show good agreement with experiments.
Designing highly efficient and stable photocatalysts is of vital importance for solar-to-fuel conversion,as a potential strategy to address the concerns of global energy crisis and environmental *** development of nov...
详细信息
Designing highly efficient and stable photocatalysts is of vital importance for solar-to-fuel conversion,as a potential strategy to address the concerns of global energy crisis and environmental *** development of novel photocatalytic materials is desirable to overcome those shortcomings of traditional semiconductor photocatalysts.
High-performance anode is hurdle for on-chip planar microsupercapacitor(MSC).Polypyrrole(PPy)is a highly attractive pseudocapacitive material,but its low cycling stability,and low adhesion with current collector hinde...
详细信息
High-performance anode is hurdle for on-chip planar microsupercapacitor(MSC).Polypyrrole(PPy)is a highly attractive pseudocapacitive material,but its low cycling stability,and low adhesion with current collector hinder its *** we propose one-prong generic strategy to boost the cycling stability of *** our strategy,the electrochemical deposition of multilayered reduced graphene oxide(rGO)on micropatterned Au is utilized,and the resultant rGO@Au pattern is then used for growing highly porous PPy nanostructures by facile electrochemical *** fabricated PPy anode on rGO@Au has quasi rectangular cyclic voltammetry curves up to-0.7 V and exceptional cycling stability,retaining82%of capacitance after 10,000 charge/discharge cycles in 2 M KCl *** outstanding reliability of PPy on rGO@Au is due to the flexibility of rGO,accommodating structural pulverization and providing a promising background for the nucleation of highly porous ***,an all-polymer based asymmetric aqueous MSC(AMSC)is constructed with PPy anode and PEDOT cathode,which exhibited excellent electrochemical performance compared with conventional symmetric MSCs based on conducting *** constructed AMSC delivered a maximum areal capacitance of 15.9 m F cm^-2(99.3 F cm^-3),high specific energy and power densities of 4.3μWh cm^-2(27.03 mWh cm^-3)and 0.36 W cm^-2(0.68 W cm^-3)at 1.4 V,*** enhanced electrochemical performances can be illustrated by nucleation mechanism,in which surface topology of r GO generates a promising background for nucleation and electrochemical growth of nanoporous pseudocapacitive conducting polymers with superior interfacial contact and improved surface area.
In order to improve the wear resistance, a kind of alumina ceramic with good wear resistance was created in an Al_2O_3-CaC_O3-SiO_2-MgO-La_2O_3（ACSML） system. The effects of La_2O_3 content on sintering temperature,...
详细信息
In order to improve the wear resistance, a kind of alumina ceramic with good wear resistance was created in an Al_2O_3-CaC_O3-SiO_2-MgO-La_2O_3（ACSML） system. The effects of La_2O_3 content on sintering temperature, bulk density, and wear rate were investigated. The wear rate of sample was as low as 0.0393‰. The wear resistance of the sample containing La_2O_3 has improved 43% than that of the sample without La_2O_3. Appropriate La_2O_3 doping could inhibit grain growth, enhance density, and purify grain boundary. La_2O_3 could diffuse into Al_2O_3 to form a solid solution and react with Al_2O_3 to form high-aluminum low-lanthanum complex oxides. The combination among Al_2O_3, the solid solution layer, and the layer of high-aluminum low-lanthanum complex oxides combined closely, which could improve grain boundary cohesion. Besides, the homogeneous distributions of elements made uniform structure. Finally, the wear resistance of alumina ceramic was improved.
In this work,homogeneous Ni0.33Co0.67Se hollow nanoprisms were synthesized successfully in virtue of Kirkendall *** is the first time for bimetallic Ni-Co compounds Ni0.33Co0.67Se to be used in lithium-ion batteries (...
详细信息
In this work,homogeneous Ni0.33Co0.67Se hollow nanoprisms were synthesized successfully in virtue of Kirkendall *** is the first time for bimetallic Ni-Co compounds Ni0.33Co0.67Se to be used in lithium-ion batteries (LIBs).Impressively,the Ni0.33Co0.67Se hollow nanoprisms show superior specific capacity (1,575 mAh/g at the current density of 100 mA/g) and outstanding rate performance (850 mAh/g at 2,000 mA/g) as anode material for *** work proves the potential of bimetallic chalcogenide compounds as high performance anode materials for LIBs.
Carbon nanotubes（CNTs） decorated with palladium were synthesized and applied to hydrogen storage of gas phase. The results show that the amount of hydrogen storage of the decorated CNTs is up to 3.9%（mass fraction...
详细信息
Carbon nanotubes（CNTs） decorated with palladium were synthesized and applied to hydrogen storage of gas phase. The results show that the amount of hydrogen storage of the decorated CNTs is up to 3.9%（mass fraction）, of which, almost 85% H2 can be desorbed at ambient temperature and pressure, while the non-decorated CNTs has a poor performance of hydrogen storage（only about 0.5%H2, mass fraction）. These indicate that it is feasible to enhance the performance of hydrogen storage of CNTs by further decoration with hydrogen-storing metals or alloys.
Electroless CoNiWP magnetic films were prepared by varying the bath pH and then characterized by energy dispersive X-ray analysis, X-ray diffraction and magnetic force microscopy, it has been found that the microstruc...
详细信息
Electroless CoNiWP magnetic films were prepared by varying the bath pH and then characterized by energy dispersive X-ray analysis, X-ray diffraction and magnetic force microscopy, it has been found that the microstructure and the magnetic properties of films were influenced greatly by the bath pH. At the bath pH 8.06, the grain size and coercivity of the films reach maximuml while the squareness （Mr/Ms） of MH curves reaches minimum. The Henkel plots indicates that the exchange-coupling interaction is very weak at this pH, which may be caused by phase-separation and large grain size, and then results in the lowest squareness. At pH above 8.5, obvious exchange-coupling interaction is observed because of the inexistence of phase-separation and the refinement of grain size.
暂无评论