Titanium diboride based composites, good candidates for contact materials, have high hardness, Young＇s modulus, high temperature stability, and excellent electrical, thermal conductivity. However a good interface of ...
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Titanium diboride based composites, good candidates for contact materials, have high hardness, Young＇s modulus, high temperature stability, and excellent electrical, thermal conductivity. However a good interface of TiB2/Cu is very difficult to achieve for oxidation of TiB2. To avoid this oxidation behavior, the in situ combusting synthesistechnology, SHS, was used to prepare TiB2/Cu composite. The characters of Ti-B-xCu SHS were studied in detail, such as combustion temperature, products phases and grain size. Based on the experimental results a proper technology way of self-high temperature synthesis plus quick press （SHS/QP） was determined and compact TiB2/Cu composites with relative density over than 97 pct of the theoretical were fabricated by this method. The properties and microstructures of these TiB2 based composites were also investigated.
An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, high...
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An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, higher density, higher flexural strength, and favorable biocompatibility compared to the regular one. During the process, cornstarch granules swelled and deformed but no fracture was observed. After the cornstarch granules bursted, alumina particles were suspended uniformly in the three-dimensional network structure to generate a much smoother surface. Below 0.5 wt% higher cornstarch content increased the flexural strength of prepared ceramics, while above 0.5 wt% the mechanical properties were compromised. Therefore the cornstarch content of 0.5% was the optimal concentration to achieve the highest mechanical strength of the prepared ceramics, with a measured flexural strength of 341 MPa, and a relative density of 96.01%.
Two novel non-fullerene small molecule acceptors were prepared with the conjugated backbone of 5 H-fluoreno[3, 2-b:6, 7-b’] dithiophene carrying the electron deficient unit of dicyanomethylene indanone(DICTFDT) and r...
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Two novel non-fullerene small molecule acceptors were prepared with the conjugated backbone of 5 H-fluoreno[3, 2-b:6, 7-b’] dithiophene carrying the electron deficient unit of dicyanomethylene indanone(DICTFDT) and rhodanine(TFDTBR), respectively. The two acceptors exhibited excellent thermal stability and strong absorption in the visible region. The LUMO level is estimated to be at-3.89 eV for DICTFDT and-3.77 eV for TFDTBR. When utilized as the acceptor in bulk heterojunction polymer solar cells with the polymer donor of PBT7-Th, the optimized maximum power conversion efficiency of 5.12% and 3.95% was obtained for the device with DICTFDT and TFDTBR, respectively. The research demonstrates that 5 H-fluoreno[3, 2-b:6, 7-b’] dithiophene can be an appealing candidate for constructing small molecular electron acceptor towards efficient polymer:non-fullerene bulk heterojunction solar cells.
Space symmetry of prehnite, which occurs in cavities and veins within Skarn from the Tieshan iron mineral deposit,Daye,Hubei province,Central China,has been determined using selected area electron diffraction (SAED) a...
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Space symmetry of prehnite, which occurs in cavities and veins within Skarn from the Tieshan iron mineral deposit,Daye,Hubei province,Central China,has been determined using selected area electron diffraction (SAED) and convergent-beam electron diffraction (CBED) on the submicrometer *** results confirm that the natural prehnite may have the structure with symmetry *** unit-cell parameters of investigated prehnite (a=0.458nm,b=0.555nm,and c=1.853nm) have been calculated by using the multicrystal diffraction rings of gold,the internal standard.
This paper studies the temperature distribution of BN, an insulating material, sintered in the Spark Plasma Sintering ( SPS) system. The temperature distributions of BN at different heating rates were measured , which...
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This paper studies the temperature distribution of BN, an insulating material, sintered in the Spark Plasma Sintering ( SPS) system. The temperature distributions of BN at different heating rates were measured , which showed that seeking for an over high heating rate in SPS is not as desirable as controlling of a suitable heating rate in order to have a fast sintering with a uniform temperature distribution.
The texture of interfacial zone between cement paste and quartz in the cement-based composites containing polyvinyl alcohol (PVA), methylcellulose (MC) and their potyblend in an amount of 10 wt % with respect to cemen...
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The texture of interfacial zone between cement paste and quartz in the cement-based composites containing polyvinyl alcohol (PVA), methylcellulose (MC) and their potyblend in an amount of 10 wt % with respect to cement, as well as the texture of dehydrated bodies of PVA, MC, and the potyblend solutions, were investigated with SEM. The network texture of the dehydrated polyblend is confirmed by comparing the texture of dehydrated bodies of PVA and MC. The network texture has restrained the movement of polyblend molecules in the cement mortar but is helpful to forming a coherent interface between cement paste and quartz. The key factor of forming the coherent interface is not the neutralization reaction between H + from hydrolysis of quarts: and OH- from hydration of cement, but the electrostatic attraction and the chemical reaction between polar groups on the polyblend molecule and cations and onions from hydrolysis of quartz and hydration of cement, respectively. The model of the coherent interface formation is that excessive [HSiO3]- and [SiO3]2- onions are bonded with the hydrated cations such as Ca2+ and Al3+ , which is confirmed by the gel containing Ca and Si on the quartz surface.
With the growing scale of the lithium-ion battery market, the number of retired lithium-ion batteries (LIBs) increase exponentially. The recycling of spent LIBs not only reduces environmental pressure but also achieve...
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With the growing scale of the lithium-ion battery market, the number of retired lithium-ion batteries (LIBs) increase exponentially. The recycling of spent LIBs not only reduces environmental pressure but also achieves resource recycling, making the necessity of recycling indispensable. Wherein the separation of cathode active materials from current collectors is a key step in the recycling process of spent LIBs, which directly affects the recycling efficiency and the reuse value of materials. Moreover, by recycling spent LIBs and extracting valuable metals from them, it is possible to alleviate the shortage of resources and realize the sustainable economic development. Among cathode materials, layered lithium nickel cobalt manganese oxide (NCM) has the highest recycling value as it contains more valuable metals such as lithium (Li), nickel (Ni), cobalt (Co) and manganese (Mn). Therefore, in this review we mainly summarize and analyze the latest research progress in the field of NCM cathode material separating from aluminum (Al) foil by focusing on its methods, principles, advantages and limitations. Also, it provides solutions to existing challenges, which have important reference significance to promote the sustainable recycling and use of spent LIBs.
By replacing hexyl chains in poly(3-hexylthiophene)(P3HT)with 2-propoxyethyls,four poly(3-(2-propoxyethyl)thiophene)(P3POET)homopolymers with comparable polydispersity indexes(PDI)and regioregularities were prepared h...
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By replacing hexyl chains in poly(3-hexylthiophene)(P3HT)with 2-propoxyethyls,four poly(3-(2-propoxyethyl)thiophene)(P3POET)homopolymers with comparable polydispersity indexes(PDI)and regioregularities were prepared herein in addition with step increment of about 7 kDa on numberaverage molecular weight(M_(n))from around 11 to 32 kDa(accordingly denoted as P11k,P18k,P25k,and P32k).When doped in film by FeCl_(3)at the optimized conditions,the maximum power factor(PF_(max))increases greatly from 4.3μW·m^(-1)·K^(-2)for P11k to 8.8μW·m^(-1)·K^(-2)for P18k,and further to 9.7μW·m^(-1)·K^(-2)for P25k,followed by a slight decrease to 9.2μW·m^(-1)·K^(-2)for *** close Seebeck coefficients(S)at PF_(max)are observed in these doped polymer films due to their consistent frontier orbital energy levels and Fermi *** main contribution to this PF_(max)evolution thus comes from the corresponding conductivities(σ).Theσvariation of the doped films can be rationally correlated with their microstructure evolution.
Scar-free wound healing is a challenging process due to the excessive deposition of extracellular matrix and *** overcome this issue,hydrogels with superior biochemical and mechanical properties have been used in comb...
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Scar-free wound healing is a challenging process due to the excessive deposition of extracellular matrix and *** overcome this issue,hydrogels with superior biochemical and mechanical properties have been used in combination with medicinal compounds as wound *** this study,a novel composite hydrogel consisting of double-crosslinked photocurable hyaluronic acid methacrylate(HAMA)and Laponite(Lap)loaded with bioactive bone morphogenetic protein 4(BMP4)was developed and thoroughly characterized for its properties such as degradation,morphology,porosity,compression,skin adhesion and load *** effect of the HAMA/Lap/BMP4 hydrogel was evaluated through both in vitro and in vivo *** the in vivo rabbit ear-scar model,the HAMA/Lap/BMP4 hydrogel dressing was found to reduce scar-related expressions ofα-SAM and decrease the ratio of collagenΙ/III in wounded ***,histopathological examination indicated that the HAMA/Lap/BMP4 hydrogel-treated groups exhibited enhanced wound repair and increased levels of collagen maintenance compared to other standard groups,ultimately leading to scarless wound ***,this sustained-release photocurable HAMA/Lap/BMP4 hydrogel offers a therapeutic approach for scar-free wound healing.
Graphene prepared by non-covalent modification of sulfonated poly(ether-ether-ketone)(SPG)was combined with polyvinylidene fluoride(PVDF)/Al to improve the PVDF/Al thermal conductivity while reducing the effect of the...
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Graphene prepared by non-covalent modification of sulfonated poly(ether-ether-ketone)(SPG)was combined with polyvinylidene fluoride(PVDF)/Al to improve the PVDF/Al thermal conductivity while reducing the effect of the thermal resistance at the graphene-polymer *** regulation rule of SPG with different contents on the energy release of fluorine-containing system was *** the content of SPG is 4%,the peak pressure and rise rate of SPG/PVDF/Al composite powder during ignition reach the maximum of 4845.28 kPa and 8683.58 kPa/*** the content of SPG is 5%,the PVDF/Al composite powder is completely coated by SPG,and the calorific value of the material reachs the maximum of 29.094 kJ/*** the design and micro-control of the composite powder,the calorific value of the material can be effectively improved,but the improvement of the mass release rate still depends on the graphene content and surface modification state.
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