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The effective characterization of the mechanical property degradation of turbine blades in service for an ultra-long-term had a significant impact on the service safety and maintenance decisions of turbine blades. In this study, the microstructure observation and mechanical property study of the K403 polycrystalline Ni-based superalloy turbine blade under four service times were carried out, using microstructure characterization methods to quantify the microstructure evolution of the superalloy at different parts of the turbine blade with increasing service time. The effects of the microstructure degradation of the superalloy under ultra-long-term service on the mechanical properties of the turbine blade were analyzed. The results show that the microstructural degradation characteristics of the superalloy turbine blades under ultra-long-term service were strongly correlated with the spatial structural characteristics of the turbine blades after service, and it was found that the carbon elements and other elements inside and at the boundary of the carbide showed regular migration behavior with the increase in service time. The regular influence of microstructural degradation of superalloy turbine blades under ultra-long-term service on their mechanical properties was demonstrated. These results can provide empirical support for the study of the predicted residual properties of nickel-based superalloy turbine blades under ultra-long-term service. [Display omitted] • Microstructure evolution of turbine blades under ultra-long-term service was studied. • Mechanical properties of turbine blades under ultra-long-term service were studied. • Influence of microstructure evolution on mechanical properties was studied. • Position-related microstructure evolution and mechanical properties was studied. • Quantitative study of carbide evolution with service time was performed. [ABSTRACT FROM AUTHOR]

The rare-earth chalcogenide Er 2 Te 3 exhibits substantial promise as an innovative thermoelectric material. However, there have been limited studies exploring its thermoelectric properties in depth. Our study employed a first-principles approach in conjunction with the semi-classical Boltzmann transport theory to investigate the collaborative modulation of the thermoelectric transport properties of Er 2 Te 3 through the concurrent application of sulfur-group elements doping and strain engineering. The findings demonstrate that, in the presence of the synergistic interplay of doping and strain, the maximum power factor (PF) of p-type Er 2 Te 3 at 300 K increases to approximately 1.8 mW·m−1·K−2, while n-type Er 2 Te 3 is elevated to approximately 18 mW·m−1·K−2. Furthermore, the cooperative effects of doping and strain augmentation raise the optimal thermoelectric figure of merit (ZT) of p-type Er 2 Te 3 material to 0.3 at 300 K and n-type Er 2 Te 3 material to 1.35 when subjecting the n-type Er 2 Te 2.82 Po 0.18 system to a −2% strain. These results suggest that even minor doping can yield similar enhancements in the thermoelectric performance of Er 2 Te 3 , particularly under conditions of smaller strain. Consequently, our work underscores the significance of synergistic interactions between doping and strain engineering as potent means to augment the thermoelectric performance of Er 2 Te 3 materials. In light of the practical feasibility of the fabrication techniques employed, this novel rare-earth chalcogenide material warrants further scrutiny and subsequent exploration within experimental domains. [Display omitted] • The effectiveness of combining doping and strain to improve the thermoelectric performance of Er 2 Te 3. • This innovative rare-earth chalcogenide material Er 2 Te 3 is a promising thermoelectric material. • It as a promising contender for room-temperature thermoelectric applications. [ABSTRACT FROM AUTHOR]

Lithium metal anode with unparalleled theoretical specific capacity, ultra-low redox potential is a magic weapon to further enhance the energy density of the rechargeable batteries. Unfortunately, fragile solid electrolyte interphase, notorious dendritic growth and infinite volume expansion seriously hindered its commercialization process. Herein, a dendrite-free 3D SnCu scaffold is obtained by a simple, flexible replacement reaction. The porous SnCu with ordered layered structure can induce uniform Li deposition, suppress dendrites growth by reducing the local current density. What's more, the introduction of metal Sn enhance the lithiophilicity of Cu substrate, therefore decreasing the Li nucleation overpotential. Compared with planar Cu foil scaffold, the synthesized 3D SnCu current collector with dendrite-free morphology significantly improve the electrochemical performance of anode. The as-prepared SnCu scaffold obtains a highly Coulombic Efficiency of 94.2 % after 250 h in half-cells, and symmetrical Li@ 3D Sn/Cu cells exhibit stable cyclic for more than 1000 h at different current density (1and 5 mAh cm−2). • The 3D SnCu scaffold with lithiophilic site is prepared by a facile in-situ replacement method. • The 3D SnCu scaffold is porous and has a multi-layered structure. • A dendrite-free anode is obtained, and the symmetric cell has overlength lifespan under different capacity. • The electrochemical performance in full cell is improved. [ABSTRACT FROM AUTHOR]

SnO 2 -based anode of lithium-ion batteries (LIB) suffers from excessive volume expansion and low conductivity, resulting in very poor capacity stability and rate capability. To solve the problems, three kinds of SnO 2 /Sn@carbon heterostructures were synthesized by a salt template following calcination using tartaric acid, p-phthalic acid and ethylenediamine tetraacetic acid with different carboxyl groups as carbon sources, respectively. The acidity, carbon atoms number and position affect the ratio of SnO 2 /Sn, the morphology and content of derived carbon, the advantage crystal plane and the surface defects of SnO 2. The carbon atoms located at carboxyl are transformed to CO and formed pores, and the carbon atoms at alkane chain are polycondensed and transformed to amorphous carbon during annealing process. The SnO 2 /Sn@C derived from tartaric acid (SnO 2 /Sn@TA) has the largest ratio of SnO 2 /Sn, which fixed on graphene-like porous carbon, exposed the most surface defects and more high energy crystal plane. The specific structure ensures structural stability and ultrahigh capacity, lower Li+ diffusion barrier energy and super rate capability. It exhibits the charge/discharge capacity of 1059.7/1064.4 mAh g−1 at 2 A g−1 after 1500 cycles and super rate performance of 399.3/404.5 mAh g−1 at 6 A g−1, which are superior to most reference data. [Display omitted] • Different heterostructures of SnO 2 /Sn@graphene-like porous carbon was synthesized. • C atoms at -COOH transform to CO to create pores, at alkane chain into amorphous C. • SnO 2 /Sn@C heterostructure decreases Li+ diffusion distance and barrier energy. • SnO 2 /Sn@C exhibits ultra-high capacity of 1064 mAh g−1 at 2 A g−1 for 1500 cycles. [ABSTRACT FROM AUTHOR]

SnS is regarded as an ideal material for electrodes in next-generation lithium-ion batteries (LIBs) due to its high specific capacity and low cost. However, the low conductivity and larger volume expansion during charge/discharge hinder its practical application. In this paper, a novel core-shell tremella fuciformis shaped SnS@Sulfur doped carbon composite (SnS@C) was constructed by reduction of as-prepared nanoflower SnS 2 and carbonazation of carboxymethyl cellulose using a crystallized NaCl as template under N 2 atmosphere. The sulfur doping carbon shell with more defects can increase not only the electrical conductivity but also enhance the mechanical strength of the SnS@C due to the larger space provided by interconnected tremella fuciformis shaped structure, as well as can provide more active sites for lithium-ions intercalation/de-intercalation by surface pseudocapacitive behavior. It remains stable capacity of 1078 mAh g−1 cycled at 0.2 A g−1 after 200 cycles, and 801 mAh g−1 even at 1.0 A g−1 for 500 cycles, and 403 mAh g−1 even at 5 A g−1 of rate performance. The simple synthesis scheme not only creates more reactive sites, but also forms a stable 3D interconnected carbon skeleton structure, which is suitable for other energy storage and conversion materials too. [Display omitted] • A core-shell tremella fuciformis shaped SnS@S doped carbon composite was obtained. • S doped carbon shell was obtained by a simple reduction of SnS 2 and carbonization method. • S doping of carbon enhance the defects and favor for Li+ storage as surface pseudocapacitive. • The carbon shell of SnS@C increases the conductivity and stablize the SnS structure. • 3D interconnected petals provide large space and more active sites for Li+ storage. [ABSTRACT FROM AUTHOR]

SnS is regarded as an ideal material for electrodes in next-generation lithium-ion batteries (LIBs) due to its high specific capacity and low cost. However, the low conductivity and larger volume expansion during charge/discharge hinder its practical application. In this paper, a novel core-shell tremella fuciformis shaped SnS@Sulfur doped carbon composite (SnS@C) was constructed by reduction of as-prepared nanoflower SnS 2 and carbonazation of carboxymethyl cellulose using a crystallized NaCl as template under N 2 atmosphere. The sulfur doping carbon shell with more defects can increase not only the electrical conductivity but also enhance the mechanical strength of the SnS@C due to the larger space provided by interconnected tremella fuciformis shaped structure, as well as can provide more active sites for lithium-ions intercalation/de-intercalation by surface pseudocapacitive behavior. It remains stable capacity of 1078 mAh g−1 cycled at 0.2 A g−1 after 200 cycles, and 801 mAh g−1 even at 1.0 A g−1 for 500 cycles, and 403 mAh g−1 even at 5 A g−1 of rate performance. The simple synthesis scheme not only creates more reactive sites, but also forms a stable 3D interconnected carbon skeleton structure, which is suitable for other energy storage and conversion materials too. [Display omitted] • A core-shell tremella fuciformis shaped SnS@S doped carbon composite was obtained. • S doped carbon shell was obtained by a simple reduction of SnS 2 and carbonization method. • S doping of carbon enhance the defects and favor for Li+ storage as surface pseudocapacitive. • The carbon shell of SnS@C increases the conductivity and stablize the SnS structure. • 3D interconnected petals provide large space and more active sites for Li+ storage. [ABSTRACT FROM AUTHOR]

• CsPbBr 3 QDs fibers were prepared by the stack-draw method and heat-treatment. • CsPbBr 3 QDs fibers used CsPbBr 3 QDs glass as core and phosphate glass as cladding. • The formation of CsPbBr 3 QDs in fibers was confirmed by Raman spectra. • The spectral properties of CsPbBr 3 QDs fibers and glasses were studied and compared. • Due to the high loss of fibers near 520 nm, laser amplification was not observed. A fiber preform was attempted to prepare by the stacking method. After drawing and heat-treatment, a composite fiber with good stability was obtained using the CsPbBr 3 glass ceramic as the core and the phosphate glass as the cladding. The formation of CsPbBr 3 quantum dots in fibers was confirmed by Raman spectra. The results of the spectral testing indicated that the emission band of fibers after heat-treatment had the same red-shift as that of CsPbBr 3 glass ceramics, but the emission peak wavelengths of the former were shorter than that of the latter. Moreover, as the length of fibers increased, the emission peak wavelength also was red-shifted. However, with the increase of heat-treatment temperature, the red-shift value of the emission peak wavelength of fibers became small as the length augmented. Due to the high loss of fibers near 520 nm, the result of laser amplification was not observed, which reflects that the preparation of fibers with short-wavelength lasers is still a challenge. [ABSTRACT FROM AUTHOR]