The structure and properties of Mg-doped SrBi4Ti4O15（SBT） were dicussed. Mg substitution into SBT had two possibilities states with the dopant amount variety. Mg cation substituted mostly into Sr^2＋ and the amount ...
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The structure and properties of Mg-doped SrBi4Ti4O15（SBT） were dicussed. Mg substitution into SBT had two possibilities states with the dopant amount variety. Mg cation substituted mostly into Sr^2＋ and the amount proportion was 68.11%.Mg ion will substitute into Ti ion site in perovskite layer when the doping amount increases. Polarization increases sharply when x=0.1 and then decreases becauses of the domain pinning. The Curie temperature of Mg-doped SBT is about 300 ℃ and there is a broad diffuse phase transition near Tc with a flat peak near the Ta of SBT.
TiAIN solar selective absorbing coatings which were deposited on 304L stainless steel using cathodic arc evaporation method were annealed under non-vacuum at different temperatures with different times. The optical pr...
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TiAIN solar selective absorbing coatings which were deposited on 304L stainless steel using cathodic arc evaporation method were annealed under non-vacuum at different temperatures with different times. The optical properties （absorptance and emittance） of the coatings were measured by a spectrophotometer. It was found that, after being annealed for 2 hours at different temperatures, the absorptance of the coatings reached the highest value of 0.92 at 700 ℃ while the emittance got the lowest value of 0.38 at 800 ℃. When the coatings were annealed at 600 ℃ for 24 hours, the optical properties changed to 0.92/0.44 （absorptance/ emittance）. By measuring the structure, morphology, elements and surface roughness of the coatings, it was found that both the elemental composition and the surface roughness of the coatings changed as a result of annealing, and these changes caused the change of the optical properties of the coatings.
Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage **...
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Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage ***-super-ionic conductor(NASICON)structural materials have stable 3D skeleton structures and open Na+transport channels,which is a very promising SIB cathode *** in the typical NASICON material Na_(3)V_(2)(PO_(4))_(3)(NVP),the number of electrons involved in NVP per formula unit is less than 2 at the stable voltage window,which limits the further improvement of battery *** this work,we report another NASICON structured Na_(3)V_(4/3)Cr_(2/3)(PO_(4))_(3)@C(NVCP@C),which is obtained by Cr-doped NVP through spray *** taking full advantage of the voltage platforms of V^(5+/4+),V^(4+/3+),and V^(3+/2+)in the window of 1.5-4.4 V,NVCP@C delivered a high discharge capacity(175 mAh g^(-1))and durable cyclability(86%capacity retention for 2000 cycles).In-situ X-ray diffraction results demonstrate that the reversible structural evolution accompanies by solid-solution reaction and two-phase reaction mechanisms co-exist during charge/discharge *** coupled with Na^(+)preembedded hard carbon(HC),the assembled NVCP@C//HC full cell delivers a high capacity(105 mAh g^(-1))and long cycling performance(70%after 1000 cycles).This Cr-doped NVP method offers new insights into the design of high-energy NASICON-structured cathode materials.
The aim of this work was to prepare MgF2 translucent ceramic by using nanopowders as raw materials and to study its *** MgF2 nanopowders were prepared using chemical precipitation and the translucent ceramics were fab...
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The aim of this work was to prepare MgF2 translucent ceramic by using nanopowders as raw materials and to study its *** MgF2 nanopowders were prepared using chemical precipitation and the translucent ceramics were fabricated by hot-pressing sintering in a vacuum environment. X-ray diffraction analysis showed that the powders were homogeneous with an average particles size about 13 nm. By comparing the results of transmission electron microscopy, it could be concluded that the porous structure of precursor powders could be improved by calcination. The SEM images of MgF2 indicated that the as-prepared ceramics were well densified at 900 ℃. The photo of the ceramic sample showed that high translucence is a main breakthrough in the field of MgF2 materials preparation. For the translucent ceramic sample sintered at 900 ℃, the Viekers hardness and density were 5.55 GPa and 98.74%, respectively, and its highest transmittance with thickness of lmm reached 87% in the wavelength from 2.5 lain to 10 btm, all which made it advantageous to be a kind of infrared windows and dome materials.
Two kinds of azo polysemicarbazides were prepared based on 3,3＇-azobis（benzoylhydrazide）（ABH） and two kinds of diisocyanates via solution *** structures were characterized by Fourier-transform infrared（FT-IR） t...
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Two kinds of azo polysemicarbazides were prepared based on 3,3＇-azobis（benzoylhydrazide）（ABH） and two kinds of diisocyanates via solution *** structures were characterized by Fourier-transform infrared（FT-IR） technique and elemental *** viscosities of the polymers were 0.32 and 0.29 dL/g and both could be dissolved in H2SO4 and polar organic *** gravimetric analysis（TGA） presented a multi-step degradation and a decomposition temperature range of 230-280 ℃.And photoisomerization of the azo polymers in solvent of N,N-dimethyl acetamide（DMAc） was confirmed by Ultraviolet-visible spectroscopy（UV-Vis）,suggested the isomerization appearing under the ultraviolet irradiation at 365 nm and recovering completely by visible light irradiation or kept in the *** electron microscopy（TEM） of polysemicarbazides before and after soaking in bovine serum albumin（BSA） solution confirmed the biocompatibility of azo polymers.
Half Heusler materials exhibit excellent thermoelectric and mechanical properties,rendering them potential candidates for advanced thermoelectric ***,the developments on interrelated devices are impeded by their inher...
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Half Heusler materials exhibit excellent thermoelectric and mechanical properties,rendering them potential candidates for advanced thermoelectric ***,the developments on interrelated devices are impeded by their inherent brittleness and limited ***,it exists the potential ductility on half Heusler materials with face-centered cubic sub-lattices through the expectation of the occurrence of shear-induced‘catching bonds’which can result in excellent ductility on other face-centered cubic materials.
Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA...
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Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.
La_(4)NiLiO_(8)-coated NCM622 samples were prepared through a sol-gel method,and the electrochemical performance as cathode materials was *** is revealed that part of the introduced La^(3+)ions produce a coating layer...
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La_(4)NiLiO_(8)-coated NCM622 samples were prepared through a sol-gel method,and the electrochemical performance as cathode materials was *** is revealed that part of the introduced La^(3+)ions produce a coating layer on the surface of NCM622 particles,while the rest occupy the 3b position of the *** optimized sample exhibits a capacity retention of 96.54%after 100 cycles under 1C rate with a discharge specific capacity of 117.54 mAh·g^(-1)under 5C rate,much higher than those of the unmodified *** results show that the addition of La^(3+)ion can greatly improve the cyclic stability and the rate performance of NCM622.
Cross-linked polystyrene/glass fiber composites were fabricated using cross-linked polystyrene （CLPS） as matrix and E-glass fiber as the reinforcement. Surfaces of E-glass fibers were modified by vinyl triethoxysila...
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Cross-linked polystyrene/glass fiber composites were fabricated using cross-linked polystyrene （CLPS） as matrix and E-glass fiber as the reinforcement. Surfaces of E-glass fibers were modified by vinyl triethoxysilane （VTES）, vinyl trimethoxysilane （VTMS） and γ-methacryloylpropyl trimethoxysilane （MPS）. The treated glass fibers were analyzed by fourier transform infrared spectroscopy （FTIR）. Dynamic mechanical thermal analysis （DMTA） and thermo-gravimetric analysis （TGA） were employed to investigate the effect of glass fibers surface modification on viscoelastic behavior and thermal properties. The morphology of fracture surfaces of various composites was observed by scanning electron microscopy （SEM）. The results revealed that these coupling agents were connected to the surfaces of the fibers by chemical bonding. Dynamic mechanical properties as well as thermal stability of the composites were improved considerablely, but to varying degrees depending on the fiber modification. The diversities of improvement of properties were attributed to the different interfacial adhesion between CLPS matrix and the glass fibers.
Nanowires are promising candidates for energy storage devices such as lithium-ion batteries, su- per（：*** and lithium-air batteries. However, simple-structured nanowires have some limitations hence the strategies to...
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Nanowires are promising candidates for energy storage devices such as lithium-ion batteries, su- per（：*** and lithium-air batteries. However, simple-structured nanowires have some limitations hence the strategies to make improvements need to be explored and investigated. Hierarchical nanowires with enhanced periormanee have been considered as an ideal candidate for energy storage due to the novel structures and/or synergistic properties. This review describes some of the recent progresses in the hierarchical nanowire merits, classification, synthesis and performance in energy storage applieat, ions. Herein we discuss the hierarchical nanowires based on their structural design from three major categories, including exterior design, interior design and aligned nanowire assembly. This review also briefly outlines the prospects of hierarchical nanowires in morphology control, property enhancement and application versatility.
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