Electrical stimulation(ES)can restore motor function after spinal cord injury(SCI).However,traditional intraspinal ES has many disadvantages,such as the need for a complex circuitry device,an external power source,and...
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Electrical stimulation(ES)can restore motor function after spinal cord injury(SCI).However,traditional intraspinal ES has many disadvantages,such as the need for a complex circuitry device,an external power source,and a second surgery to remove the *** materials have received increasing at-tention due to their potential to convert ambient mechanical energy into ES without an external power source or implantation of ***,a novel polydopamine(PDA)coated barium titanate(BaTiO_(3))nanoparticles(BaTiO_(3)@PDA)incorporated silk fibroin(SF)hydrogel(SFBT)was *** SFBT hy-drogel was crosslinked by horseradish peroxidase(HRP)/hydrogel peroxide(H_(2)O_(2))to integrate the piezo-electric potency of BaTiO_(3)with the thermal sensitivity of HRP/H_(2)O_(2)for SCI *** hydrogel con-taining 5%(w/v)BaTiO_(3)@PDA nanoparticles(SFBT-5),which was selected for in vivo study,exhibited a short gelation time(5 min),suitable storage modulus(925±35 Pa),and wireless ES(average current of 124 nA).Moreover,Basso-Beattie-Bresnahan(BBB)scores test and footprint analysis demonstrated that the SFBT-5 hydrogel successfully enhanced motor functional recovery of *** histopathological assess-ments,the SFBT-5 hydrogel significantly accelerated spinal cord healing,as indicated by smaller lesion cavities(∼16.7%of the SCI group).Meanwhile,the SFBT-5 hydrogel accelerated neurogenesis,facilitated axon regrowth and synapse formation,and promoted ***,this study highlights the potential of piezoelectric hydrogels for SCI regeneration.
La substituted Ba(Mg_ 1/3Nb_ 2/3)O_3 ceramics was expected to enhance the 1∶2 ordering degree of B-site ions due to the existence of vacancies that promote cation movement and result in improvement of the Q_f value. ...
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La substituted Ba(Mg_ 1/3Nb_ 2/3)O_3 ceramics was expected to enhance the 1∶2 ordering degree of B-site ions due to the existence of vacancies that promote cation movement and result in improvement of the Q_f value. The relation between the microstructure and microwave dielectric properties of Ba_ 1-xLa_ 2x/3(Mg_ 1/3Nb_ 2/3)O_3 ceramics was investigated. La substituted Ba(Mg_ 1/3Nb_ 2/3)O_3 ceramics can improve the sinterability of specimens. Both 1:2 ordering degree and grain size increase as A-site vacancies increase. This can be explained by the existence of vacancies that promote cation movement. The Q_f value increase with small La content, then decrease rapidly. The highest Q_f value achieved in this investigation is about 55000 GHz for Ba_ 0.995La_ 0.01/3(Mg_ 1/3Nb_ 2/3)O_3. The improvement of Q_f value with A-site vacancies is related to the increase of the degree of B-site ordering and grain size of the specimen.
Zn-air batteries(ZABs)as a class of promising energy storage setups are generally powered by efficient and robust catalysts at the oxygen-involving *** the existing non-noble catalysts have outperformed noble Pt bench...
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Zn-air batteries(ZABs)as a class of promising energy storage setups are generally powered by efficient and robust catalysts at the oxygen-involving *** the existing non-noble catalysts have outperformed noble Pt benchmark in the alkaline liquid-state ZABs,to the best of our knowledge few have excelled Pt in quasi-solid-state(QSS)***,we found that an integrated Mn-Co cathode derived from the bimetallic Mn/Co metal organic frameworks generates a 1.4-fold greater power density in the QSS ZABs than a Pt cathode while its power density in liquid-state ZABs is only 0.8-fold of the ***,such Mn-Co catalyst delivers high-rate oxygen reduction reaction(ORR)capability with half-wave potential of 0.84 *** in-depth characterizations and analyses have demonstrated that the Co and Mn species show the specific affinity towards H_(2)O and O_(2),respectively,synergizing the ORR process in the water-deficient environment of QSS *** work has enlightened the rational design of non-noble metal catalysts to improve the power density of QSS ZABs.
Microwave boriding layer microstructure of carbon steels and its diffusion mechanics were studied. The results show that the existence of microwave field in the boriding can't change the growth mechanics of boriding ...
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Microwave boriding layer microstructure of carbon steels and its diffusion mechanics were studied. The results show that the existence of microwave field in the boriding can't change the growth mechanics of boriding layer. Compared with conventional boriding, if the treatment temperature and time remain constantly, the descend rate of the boriding layer thickness with the increase of carbon content of steel is smaller. The diffusion activation energy ofT8 steel is 2.6× 10^5 J/mol between the temperature of 750 ℃ and 900 ℃ in microwave field, which is in the same order of conventional boriding.
Reduced graphene oxide(rGO)enhanced B_(4)C ceramics was prepared by SPS sintering,the enhancement effect of rGO on the microstructure and mechanical properties of composites was studied through experiments and numeric...
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Reduced graphene oxide(rGO)enhanced B_(4)C ceramics was prepared by SPS sintering,the enhancement effect of rGO on the microstructure and mechanical properties of composites was studied through experiments and numerical *** results show that the composite with 2wt%rGO has the best comprehensive mechanical *** with pure boron carbide,vickers hardness and bending strength are increased by 4.8%and 21.96%,*** fracture toughness is improved by 25.71%.The microstructure observation shows that the improvement of mechanical properties is mainly attributed to the pullout and bridge mechanism of rGO and the crack *** on the cohesive force finite element method,the dynamic crack growth process of composites was *** energy dissipation of B_(4)C/rGO multiphase ceramics during crack propagation was calculated and compared with that of pure boron carbide *** results show that the fracture energy dissipation can be effectively increased by adding graphene.
Selenium sulfide/double-layered hollow carbon sphere (SeS2/DLHC) composites have been designed as high-performance cathode materials for novel Li-SeS2 batteries. In the constructed composite, SeS2 is predominantly e...
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Selenium sulfide/double-layered hollow carbon sphere (SeS2/DLHC) composites have been designed as high-performance cathode materials for novel Li-SeS2 batteries. In the constructed composite, SeS2 is predominantly encapsulated in the interlayer space of DLHCs with a high loading of 75% (weight percentage) and serves as the active component for lithium storage. The presence of Se in the composite and the carbon framework not only alleviate the shuttling of polysulfide, but also improve the conductivity of electrodes. Migration of active materials from the interlayer void to the hollow cavity of DLHCs after cycling, which further mitigates the loss of active materials and the shuttle effect, is observed. As a result, the SeS2/DLHC composite delivers a high specific capacity (930 mA.h.g-1 at 0.2 C) and outstanding rate capability (400 mA.h.g-1 at 6 C), which is much better than those of SeS2/single-layered hollow carbon sphere, Se/DLHC, and S/DLHC composites. Notably, the SeS2/DLHC composite shows an ultralong cycle life with 89% capacity retention over 900 cycles at 1 C, or only 0.012% capacity decay per cycle. Our study reveals that both SeS2 and the double-layered structures are responsible for the excellent electrochemical performance.
Emerging stimuli-responsive composite probes active in the second nearinfrared window(NIR-II,1000–1700 nm)hold vast potential for improving in vivo imaging performance with minimized noise *** interactions among exte...
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Emerging stimuli-responsive composite probes active in the second nearinfrared window(NIR-II,1000–1700 nm)hold vast potential for improving in vivo imaging performance with minimized noise *** interactions among external irradiation,shell species,and the emissive core are key factors in the design of smart *** external irradiation provides energy for shell species and the emissive core to generate intense NIR-II fluorescence signals,while the energy transfer process hinders NIR-II emission in the inner structure of smart composite ***,if pathophysiological stimuli interrupt the above processes,then NIR-II fluorescence signals are *** review covers NIR-II imaging based on diverse smart composite NIR-II fluorescent probes responding to various biological stimuli,including ONOO−,overexpressed reactive sulfur species,abnormally expressed enzymes,and abnormal levels of physiological ***,to appreciate these advances,the challenges and perspectives of stimuliresponsive composite NIR-II probes are highlighted.
The 93 W and Mo1 refractory metals were bonded with different Cu_(1-x)Ni_(x) coating interlayers of various Ni content using plasma-activated sintering at 700℃.The effects of the Ni content in the Cu_(1-x)Ni_(x) coat...
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The 93 W and Mo1 refractory metals were bonded with different Cu_(1-x)Ni_(x) coating interlayers of various Ni content using plasma-activated sintering at 700℃.The effects of the Ni content in the Cu_(1-x)Ni_(x) coating interlayer on the interfacial microstructure evolution and mechanical properties of the W/Mo joints were *** maximum average shear strength of the W/Mo joint was 316.5 MPa when the Ni content of the Cu_(1-x)Ni_(x) coating interlayer was 25%.When the Ni content of the Cu_(1-x)Ni_(x) coating interlayer was below 50%,the atomic diffusion at the W/Mo joint interface was adequate without the formation of intermetallic compounds,as demonstrated by the High Resolution Transmission Electron Microscope analyses of the *** presence of Ni in Cu_(1-x)Ni_(x) promoted diffusion bonding at the interface,which contributed to the high mechanical properties of the W/Mo *** an increase in the Ni content of the Cu_(1-x)Ni_(x) coating interlayer,the Mo Ni intermetallic compound(IMC)nucleated and grew at the Cu1-xNix coating/Mo1 *** the Ni content of the Cu_(1-x)Ni_(x) coating interlayer was above 50%,the generation of a brittle Mo Ni IMC weakened the shear strength of the W/Mo joint dramatically.
Energy and environmental issues are becoming more and more severe and renewable energy storage technologies are vital to solve the *** metal(Li,Na,Mg,Al)-sulfur batteries with low-cost and earth-abundant elemental sul...
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Energy and environmental issues are becoming more and more severe and renewable energy storage technologies are vital to solve the *** metal(Li,Na,Mg,Al)-sulfur batteries with low-cost and earth-abundant elemental sulfur as the cathode are attracting more and more interest for electrical energy storage in recent ***-sulfur(Li-S),room-temperature sodium-sulfur(RT Na-S),magnesium-sulfur(Mg-S)and aluminum-sulfur(Al-S)batteries are the most prominent candidates among *** obvious obstacles are hampering the developments of metal-sulfur ***-S and Na-S batteries are encumbered mainly by anode dendrite issues,polysulfides shuttle and low conductivity of ***-S and Al-S batteries are short of suitable *** this review,relationships between various employed nanostructured materials and electrochemical performances of metal-sulfur batteries have been ***,the selections of suitable electrolytes,anode protection,separator modifications and prototype innovations are all crucial to the developments of metal-sulfur batteries and are discussed at the same ***,we give a review on the advances of Li-S,RT Na-S,Mg-S and Al-S batteries from the point of view of materials,and then focus on perspectives of their future developments.
Recently,dimensionless figure of merit (ZT) beyond 1.0 has been demonstrated in diamondoid Cu2SnSe3,positioning it as a low-cost and ecofriendly thermoelectric alternative,and sparking intense interest in further op...
Recently,dimensionless figure of merit (ZT) beyond 1.0 has been demonstrated in diamondoid Cu2SnSe3,positioning it as a low-cost and ecofriendly thermoelectric alternative,and sparking intense interest in further optimizing its thermoelectric ***,its intrinsic monoclinic structure and the compact packing of tetrahedral coordination lead to a light valence band and high thermal conductivity,which impede further performance improvement in ***,developing effective approaches to altering the local structure of Cu2SnSe3is important for further optimizing its thermoelectric ***,we identified and thoroughly investigated the atomic off-centering behavior in Cu2SnSe3,and demonstrated the electronic and phonon transport properties of Cu2SnSe3can be significantly enhanced by carefully modifying its monoclinic lattice into a distorted zinc-blende cubic structure via introducing Cd and off-centering Ag *** structure transition leads to band convergence and a reduction in the deformation potential of the material,resulting in a 7-fold enhancement in the density-of-state effective mass and an 85%increase in carrier ***,the off-centering effect results in strong acoustic-optical phonon scattering and an ultra-low lattice thermal conductivity of 0.3 W ***,a maximum ZT of 1.3 was obtained at 800 K for the Cu1.85Ag0.15Sn0.9Cd0.1Se3.
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