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Abstract Nanostructure CuFe 2 O 4 /CuO composites are synthesized via a precipitation method with different surfactants mediated Prussian blue analogues (PBAs) as precursors and following calcination in air. Comparatively, P-CuFe 2 O 4 /CuO (synthesized with PVP) and graphene oxide (GO) are hydrothermal processed to obtain P-CuFe 2 O 4 /CuO/reduced-GO. The PBAs precursors present as small spherical particles with PVP (P-CuPB), irregular polygon blocks with SDBS (S-CuPB) and CTAB (C-CuPB). Porous CuFe 2 O 4 /CuO with different size are obtained after calcining the PBAs and employed as anode of lithium ion batteries. The P-CuFe 2 O 4 /CuO exhibits an excellent capacity of 630.5 mAh g−1 with coulombic efficiency (CE) above 97%, which are better than the other two samples, and P-CuFe 2 O 4 /CuO/R-GO shows further improved reversible and stable capacity of 720 mAh g−1 with CE above 99% cycled at 500 mA g−1 even after 300 times. The results imply that surfactants can influence the particle structure and lithium storage performance. Besides, R-GO can effectively increase lithium ions insertion/de-insertion kinetics by supplying the matrix and buffer cushion for metal oxide volume changing during cycling. Graphical abstract Image 1 Highlights • Nanostructured CuFe 2 O 4 /CuO mediated by PBAs with different surfactants are obtained. • A simple soft-template synthesis mechanism was proposed. • CuFe 2 O 4 /CuO anode synthesized by PVP exhibited better lithium storage performance. • CuFe 2 O 4 /CuO/R-GO anode shown 720 mAh g−1 at 0.5 A g−1 even after 300 cycles. [ABSTRACT FROM AUTHOR]

Abstract A composite foil is proposed to join three-dimensional C f /SiC to Nb substrate, which is composed of Ti-Zr-Cu-Ni amorphous foil and Ti foil, in order to reduce the brazing temperature, meanwhile keep the high serving temperature. During the brazing process, the dissolution of Ti from Ti foil and Nb from substrate into the brazing alloy was discovered. Such dissolution contributes to a variational composition and microstructure of the brazing seam. The β-Ti eutectoid transformation was suppressed. A high content of the in-situ forming (Ti,Nb) solid solution phase was observed in the brazing seam after brazing process, which is considered to be favorable for the joint for its low elastic modulus and good deformability. Defect-free joints are successfully obtained in this work using this composite foil. The maximum shear strength of the joint is measured to be 121 MPa at ambient temperature, and 83 MPa at 600 °C, respectively. Highlights • The (Ti,Nb) solid solution phase ((Ti,Nb) ss) was in-situ formed. • (Ti,Nb) ss remarkably improved the deformability of joints. • Ti solid solutions markedly increased by increasing Ti content in brazing seams. • The shear strength of joints enhanced more than five-fold. [ABSTRACT FROM AUTHOR]

Abstract This research employed an in-situ growth method to fabrication of multi-walled nanotubes (MWCNTs)/Fe 3 O 4 electromagnetic absorber. Such a binary material system is featured with good impedance matching behavior and moderate attenuation ability, thus exhibits excellent electromagnetic absorption properties. The results reveal that MWCNTs/Fe 3 O 4 exhibits distinct polarization relaxation phenomenon which inducted by interface polarization. This intensity of interface polarization is tunable by controlling the contact area of Fe 3 O 4 and MWCNTs. Due to the contribution of interface polarization loss behavior, the MWCNTs/Fe 3 O 4 sample achieves a wide band electromagnetic absorption property which the frequency region with RL < −10 dB can covers 5.7 GHz at 1.5 mm. The method of utilizing interface strategy to boost dielectric loss ability has an efficient way to gain wide band electromagnetic absorber. Graphical abstract Image 1 Highlights • MWCNTs/Fe 3 O 4 shows dual magnetic/dielectric loss ability. • The weight ratio of MWCNTs/Fe 3 O 4 is tunable. • The effective frequency of MWCNTs/Fe 3 O 4 was up to 5.7 GHz. [ABSTRACT FROM AUTHOR]

Cu-MOF with a hollow morphology was successfully synthesized by a novel and simple coordination transformation reaction of [Cu(NH 3 ) 4 ] 2+ with benzenetricarboxylic acid (H 3 BTC) under ultrasound irradiation for the first time. Then, novel hollow porous CuO/C nanorods were prepared by calcining this Cu-MOF at low temperature (250 °C) in air. The morphology and electrochemical properties of the samples were markedly affected by the calcination temperature. As anode materials for lithium-ion batteries, the hollow porous nanorod structure and the presence of carbon greatly enhanced the electrochemical performance of the CuO/C nanocomposite. The reversible specific capacity of CuO/C was 505 mA h g −1 at a current density of 100 mA g −1 after 200 cycles, which is much higher than that of the CuO samples calcined at 300 °C and 350 °C (250.1 mA h g −1 and 192.3 mA h g −1 , respectively) in air. The CuO/C nanocomposite also exhibited a more favorable rate capability than CuO. The superior electrochemical performance makes this nanocomposite a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

Highly ordered TiO 2 nanotube arrays for water splitting have been prepared by anodizing Ti sheet in ethylene glycol electrolyte. The influence of water content in electrolyte on the nanotube structure, photocurrent, photoconversion efficiency and hydrogen production was systematically investigated. The morphologies of TiO 2 nanotube arrays were characterized by FESEM and the photoelectrochemical (PEC) performance was carried out by the electrochemical work station. The photocatalytic activity of TiO 2 nanotubes was evaluated by hydrogen generation in a two-compartment PEC cell without any external applied voltage. The results indicated that the tube structure, tube length, photoelectrochemical properties and hydrogen production strongly depended on the water content. At higher water content, the tubular structure was destroyed and the tube length decreased, leading to the reduction of photocurrent and hydrogen production. TiO 2 nanotubes anodized in 2 vol% H 2 O demonstrated the highest hydrogen production of 109 μmol/(cm 2 h). Moreover, based on the result, a growth model of TiO 2 nanotubes anodized with different water contents was proposed in this study. [ABSTRACT FROM AUTHOR]

The core-shell and well-mixed morphologies of Co-M (M = Ag, Au, Pd or Pt) clusters are investigated. The interatomic interaction of these clusters is described by the many-body Gupta potential, and the stable structures are optimized using adaptive immune optimization algorithm. Results show that all 55-atom Co-Au and Co-Pd clusters adopt Mackay icosahedral motifs, but Co-Ag and Co-Pt clusters have more configurations. The number of bonds indicates that Co-Ag, Co-Au and Co-Pd clusters take the core-shell structures. In these core-shell structures, Co atoms occupy the inner core, and Ag and Pd atoms tend to scatter on the surface, but Au atoms prefer packing together, which is explained by atomic radii, cohesive energy and surface energy. However, the investigated Co-Pt clusters favor well-mixed pattern. Furthermore, there exists difference among the relative stability of these clusters by energy analysis. Moreover, the influence of the noble metals on the structures of Co 13 M n ( n = 1–41) clusters are studied. The atomic distribution of Co and noble metals in Co 13 M n clusters is analyzed, which is consistent with that in 55-atom Co-M clusters. [ABSTRACT FROM AUTHOR]

Abstract: AM-SC1 (Advanced Magnesium-Sand Casting Alloy 1) is a heat-resisting Mg-RE based alloy which has been widely applied in engine block. It would be an effective way to decrease the cost of the alloy by replacing Nd with Ca as addition. The effects of Ca addition on the microstructure and mechanical properties of the alloy were investigated by means of Brinell hardness measurement, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction and tensile tests at room and elevated temperatures. As the addition of Ca is 1.5%, the alloy shows the finest grain size of 16μm which also contributes to the highest hardness and strength of 62.1 HB and 148MPa, respectively. After T6 treatment (solid solution treatment at 500°C for 7h and aging treatment at 200°C for 20h), the morphologies of the phases in the Ca-containing alloys change from net-like to fine short-block and particle-like shapes, and its strengths at RT, 175°C and 200°C are correspondingly improved to 186MPa, 166MPa and 140MPa, respectively. [Copyright &y& Elsevier]

Abstract: The club-shape (Y0.98Yb0.02)3Al5O12 nanoparticles (YAG:Yb3+), which were synthesized by the co-precipitation method, had been successfully coated with silica from hydrolysis and condensation of tetraethyl orthosilicate (TEOS). The thickness of SiO2 shell can be tuned by the amount of TEOS. The influence of different modifying surfactants, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG) and cetyltrimethyl ammonium bromide (CTAB), on the final product had been investigated. The morphology and structure of the nanoparticles were characterized by scanning electron microscopy (SEM) and transmission electronic microscopy (TEM). Surface composition of the samples was studied by X-ray photoelectron spectroscopy (XPS). The results show that PVP is much more beneficial to the dispersion and formation of the core–shell structure than the others. The near-infrared photoluminescence emissions of the nanoparticles were also investigated under the excitation of 940nm laser diode. The results indicate that SiO2 shell can increase the luminescence intensity and lifetime of YAG:Yb3+ in the near infrared region emissions because the shell can reduce content adsorbed on the surface of the samples. [Copyright &y& Elsevier]

Abstract: Bi2S3 microcrystallites with three-dimensional (3D) superstructures were synthesized by the reaction of bismuth nitrate (Bi(NO3)3) with sodium O-isopropyldithiocarbonate (isopropyl xanthate, C3H7OCS2Na) at 80°C in N,N-dimethylformamide (DMF) solution without any surfactants. It was observed that Bi2S3 crystalline nanorods aggregated to urchin-like globules in the microscale when C3H7OCS2Na was slowly added to Bi(NO3)3 in DMF solution at 80°C, while cockscomb-like microspheres aggregated by Bi2S3 nanobelts with a typical width of ∼20nm were obtained if two precursors were mixed at room temperature and then heated to 80°C. Possible mechanisms for the formation of 3D Bi2S3 microcrystals were proposed. The structures of Bi2S3 crystals were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and laser Raman spectroscopy. [Copyright &y& Elsevier]

Abstract: Monodispersed SiO2 @ Y2O3:Eu3+ and SiO2 @ Y2O3:Eu3+ @ SiO2 nanospheres contain SiO2 as core and Y2O3:Eu3+ as shell or another SiO2 shell coated on the surface of SiO2 @ Y2O3:Eu3+ particles were synthesized, respectively. The synthesis of core–shell particles SiO2 @ Y2O3:Eu3+ involved the SiO2 core ultrasonically dispersed into a certain amount of polyethylene glycol solution, and the deposition of Y2O3:Eu3+ on the surface of SiO2 core through homogeneous precipitation of Y3+ and Eu3+ using urea as precipitator. More over, the particles SiO2 @ Y2O3:Eu3+ as core was ultrasonically dispersed into a certain amount of ethanol and followed by sol–gel processing of tetraethoxysilane to form another silica shell. The morphology structures and sizes of the resulting particles were analyzed by SEM and TEM, which indicated that the resulting particles dispersed regularly and the microstructures of the particles are clearly core–shell or core–shell–shell structures. XRD patterns characterized the crystal structures of deposited Y2O3:Eu3+ shell or SiO2 shell after heat treatment at 900°C. Photoluminescence determination showed that both the phosphors can be excited by ultra violet at 254nm which showed red-shift. Under the excitation at 254nm, the Eu3+ ion mainly shows its characteristic red (612nm, 5D0–7F2) emission in the particles from Y2O3:Eu3+ shell. The emission intensity of Eu3+ was affected by the SiO2 core or shell in some extent. [Copyright &y& Elsevier]

Abstract: A systematic study has been carried out for the stepwise chlorination-chemical vapor transport (SC-CVT) characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by the vapor complexes KLnCl4 and NaLnCl4 (Ln=Sc, Y and La–Lu) used NaCl and KCl as complex former, respectively. The results showed that the SC-CVT characteristics are similarly for NaCl and KCl as complex former, the main deposition temperature of the rare earth chlorides LnCl3 is in the increasing order ScCl3 ScCl3, and they are much higher than that of most lanthanoid chlorides. For lanthanoids, the total transported amount of chloride increases systematically from the early lanthanoid chlorides to the end one except for EuCl3 and GdCl3 mediated by KCl and NaCl as complex former, respectively, which showed the divergence effect of Gd in the total transport efficiency. But there are some differences in SC-CVT characteristics of pure rare earth oxide mediated by KCl and NaCl as complex former, that is the main deposition temperature region for the same rare earth element was lower for KCl than that for NaCl as complex former except for LaCl3, CeCl3, YbCl3 and LuCl3, while the total transport amount of rare earth chloride for KCl as complex former is higher than that for NaCl except for LaCl3 and EuCl3. More over, the discussion was carried out for Sc and Y on the one hand and the lanthanides contain 4f electron as another hand based on the 4f electron hybridization assumption. Further more, the transport characteristics of rare earth oxides with alkaline chlorides as complex former in this study were compared to that with AlCl3 as complex former. [Copyright &y& Elsevier]

Abstract: Mutual separation characteristics for ternary oxide mixtures Y2O3–Ho2O3–Er2O3, in which these three kinds of rare earth ion (III) have very similar ion radius values, have been investigated using a stepwise chlorination-chemical vapor transport (SC-CVT) reaction mediated by vapor complexes KLnCl4 in different temperature gradients. Both the main deposition temperature region tendency and total transport amounts of chlorides for YCl3 with respect to the ion radius of Y (III) were exceptional compared with those of LnCl3 (Ln=Ho and Er), which were observed both in the degressive temperature gradient and the wave type temperature gradient. All the three chlorides produced from the oxide mixtures concentrated in the middle temperature range from 1150 to 1000K (FN=5–9) in degressive temperature gradient. The deposition temperature of the largest chlorides amounts was at FN=6 for YCl3 and FN=8 for HoCl3 and ErCl3, which in the order of YCl3 >HoCl3 ≈ErCl3. Total transported yields of the chlorides was in the order of HoCl3 >ErCl3 >YCl3 in the two type temperature gradients. The largest separation factors 7.48 for Ho:Y, 5.10 for Er:Y and 7.58 for Ho:Er in the lower temperature region were observed in the degressive temperature gradient, respectively. Furthermore, the improved separation factor values of 23.8 for Ho:Y and 19.2 for Er:Y were obtained in the wave type temperature gradient due to variation of the dynamic conditions of CVT. The results were discussed on the difference between the ionic structure of Y and 4f lanthanoid elements of Ho and Er and verified that the ionic radius of the rare earth is one of the decisive factors of CVT reaction only for lanthanoid elements, not for Y. On the other hand, the cooperate effect among the three elements and the variation of the dynamic conditions of CVT have been the important factors to influence the separation efficiency of the three elements. [Copyright &y& Elsevier]

Abstract: Mutual separation characteristics for a series of rare earth elements Sc, Y, La, Nd, Sm, Gd, Ho and Er from their binary oxide mixtures Er2O3–Sc2O3, Er2O3–Y2O3, Er2O3–La2O3, Er2O3–Nd2O3, Er2O3–Sm2O3, Er2O3–Gd2O3 and Er2O3–Ho2O3 has been investigated using a stepwise chlorination-chemical vapor transport (SC-CVT) reaction mediated by vapor complexes KLnCl4. The total transported yield of the chlorides produced from the oxide mixtures was in the order of ErCl3 >ScCl3, ErCl3 >YCl3, ErCl3 >LaCl3, ErCl3 >NdCl3, ErCl3 >SmCl3, ErCl3 >GdCl3 and HoCl3 >ErCl3, and the total separation factors are 13.0 for Er:Sc, 1.49 for Er:Y, 1.48 for Er:La, 1.15 for Er:Nd, 2.33 for Er:Sm, 2.72 for Er:Gd and 1.10 for Ho:Er. The largest separation factors 1213.8 for Er:Sc, 6.37 for Er:Y, 189.3 for Er:La, 100.6 for Er:Nd, 105.7 for Er:Sm, 27.8 for Er:Gd and 1.14 for Er:Ho in the lower temperature region, while 102.7 for La:Er, only 14.3 for Nd:Er, 16.7 for Sm:Er, 4.0 for Gd:Er and 2.04 for Ho:Er in the higher temperature region were observed, respectively. The results showed the obvious divergence effect of Gd both in the largest separation factors, the total separation factors and total transport efficiency. Furthermore, the results were discussed on the difference of ionic radius of Sc and Y on the one side and the lanthanoid elements of La, Nd, Sm, Gd, Ho and Er on the other hand, and verified that the ionic radius is one of the decisive factors only for lanthanide elements, not for Sc and Y. [Copyright &y& Elsevier]

Abstract: Mutual separation characteristics for binary oxide mixtures Y2O3–Dy2O3, Y2O3–Er2O3 and Ho2O3–Er2O3, in which these four kinds of rare earth ion(III) have very similar ion radius values, using a stepwise chlorination–chemical vapor transport (SC–CVT) reaction mediated by vapor complexes KLnCl4 have been investigated in different temperature gradients. The unexpected results, together with that for Y2O3–Ho2O3 reported previously, are used to make a comparative analysis for the effect of ion radius values on the SC–CVT reaction for mutual separation of rare earths. Both the main deposition temperature region tendency and total transport amounts of chlorides for YCl3 with respect to the ion radius of Y(III) were exceptional compared with those of LnCl3 (Ln=Dy, Ho and Er), which were observed both in the degressive temperature gradient and the wave-type temperature gradient. The main deposition temperature of the chlorides produced from the oxide mixtures was in the order of DyCl3>YCl3, HoCl3ErCl3, total transported yields of the chlorides was in the order of DyCl3>YCl3, HoCl3>YCl3, ErCl3>YCl3 and HoCl3>ErCl3, and the largest separation factors 11.49 for Dy:Y, 15.28 for Ho:Y, 6.37 for Er:Y and 2.04 for Ho:Er in the lower temperature region were observed in the degressive temperature gradient, respectively. The results were discussed on the difference of ionic structure of Y on the one side and 4f lanthanoid elements of Dy, Ho and Er on the other hand, and verified that the ionic radius of the rare earth is one of the decisive factors of CVT reaction only for lanthanoid elements, not for Y. Furthermore, the improved separation factor values of 4.22 for Ho:Er and 3.20 for Er:Ho were obtained in the wave type temperature gradient due to variation of the dynamic conditions of CVT. [Copyright &y& Elsevier]

Mutual separation characteristics for binary oxide mixtures Ho2O3–Sc2O3, Ho2O3–Y2O3, Ho2O3–La2O3, Ho2O3–Nd2O3 and Ho2O3–Sm2O3 using a stepwise chlorination-chemical vapor transport (SC-CVT) reaction mediated by vapor complexes KLnCl4 have been investigated. The total transported yields of the chlorides produced from the oxide mixtures was in the order of HoCl3>ScCl3, HoCl3>YCl3, LaCl3>HoCl3, HoCl3>NdCl3 and HoCl3>SmCl3, the main deposition temperature of the chlorides is in the increasing order of ScCl3, and the largest separation factors 19.0 for Sc:Ho, 15.3 for Ho:Y, 125.0 for Ho:La, 10.6 for Ho:Nd and 13.6 for Ho:Sm in the lower temperature region, while 1480.0 for Ho:Sc, only 2.1 for Y:Ho, 50.0 for La:Ho, 15.2 for Nd:Ho and 9.0 for Sm:Ho in the higher temperature region were observed, respectively. The results were discussed on the difference of ionic radius of Sc, Y and La on the one side and 4f lanthanides elements of Ho, Nd and Sm on the other hand, and verified that the ionic radius is one of the decisive factors only for lanthanide elements, not for Sc and Y. Furthermore, the SC-CVT characteristics mediated by vapor complexes KLnCl4 of binary oxides Ho2O3–Ln2O3 were studied compared with that of Y2O3–Ln2O3 mediated by KLnCl4 or LnAlnCl3n+3 for the ionic radius of Ho3+ and Y3+ are very near. [Copyright &y& Elsevier]

Stepwise chlorination–chemical vapor transport (SC–CVT) reaction has been investigated for the rare earth oxide mixtures Gd2O3–Tb4O7, Tb4O7–Dy2O3 and Dy2O3–Ho2O3 mediated by vapor complexes LnAlnCl3n+3 (where Ln=rare earth elements). The results show selective deposition of lighter elements at higher temperatures. The separation factors are 5.84 for Gd/Tb, 3.72 for Tb/Dy and 3.13 for Ho/Dy when using CO as the CVT carrier gas. A combination of enhanced separation factor with reduced total transport yield is also observed for the Tb4O7–Dy2O3 system when using argon as the CVT carrier gas. [Copyright &y& Elsevier]

Inverse spinel SnFe 2 O 4 as an anode material for lithium-ion batteries (LIBs) suffers from poor cycling stability due to its lower conductivity and excess volume change during charge/discharge process. In order to overcome the obstacles, a series of SnFe 2 O 4 @reduced graphene oxide (rGO) composites with different amount of Sn(Fe)–C bonds between SnFe 2 O 4 and rGO interface are synthesized through a simple one-pot solvothermal method and subsequent sintering at different temperatures. The composite with higher Sn(Fe)–C bonds content exhibits higher charge/discharge capacities of 1010/1020 mAh g−1 at 0.5 A g−1 for 300 cycles, and a better rate capability of 620 mAh g−1 at 2.0 A g−1. The synergistic effect of larger content of Sn(Fe)–C bonds and the formed flower-like networks between the pulverized SnFe 2 O 4 and the rGO interface during charge/discharge is favor to improve the kinetics of SnFe 2 O 4 , because the networks are acted as the transport highway for electronics and lithium-ions. Moreover, the higher content and strong action of Sn(Fe)–C bonds can prevent the SnFe 2 O 4 nanoparticles suffer from excessively volume change and pulverize during cycling. Designing chemically bonded metal oxides with graphene composite could provide a simple way to improve the cycle stability and rate capability of the LIBs. Image 1 • Various amount of Sn(Fe)–C bonds between SnFe 2 O 4 and graphene interface are obtained. • The composite with higher content of Sn(Fe)–C bonds exhibits higher capacities. • Flower like networks formed on SFG interface act as transport highway for Li+. • The anode shows high stable capacity of 1020 mAh g−1 at 0.5 A g−1 for 300 cycles. [ABSTRACT FROM AUTHOR]

In this research, electrolytic manganese residues (EMRs) modified by NaOH, ultrasonic etching and microwave-assisted heating treatment (called M-EMRs hereafter) were used as a novel adsorbent to remove Arsenic (V) [As(V)] from synthetic wastewater. Results showed that M-EMRs were of nanosheet structure in sizes of about 100–300 nm; the percentage of Fe and Mn on the surface of M-EMRs increased, and Fe and Mn existed in the forms of FeS, FeOOH, Fe 3 O 4 , and MnO 2. The As(V) concentration in the liquid decreased from 50 to 0.038 mg/L. The maximum adsorption capacity of E-EMRs for As(V) was 23.96 mg/g. The presence of low concentration of salt such as NaCl, Na 2 CO 3 , Na 2 HPO 4 , and Na 2 SO 4 showed limited inhibition on the adsorption of As(V). Moreover, M-EMRs could be regenerated with 3% NaOH solution and reused for 5 times. Preliminary analysis indicates the application potential of M-EMRs in As-contaminated industrial wastewater. Image 1 • For the first time, EMRs were modified to be an As(V) adsorbent (M-EMRs). • The adsorption capacity of M-EMRs for arsenic is 23.96 mg/g. • The adsorption capacity is greater than hematite, halloysite, and steel slag. • The treated As(V)-wastewater is below the tolerance level of national standards. • The M-EMRs is stable in a wide pH range and with the coexistence of multiple ions. [ABSTRACT FROM AUTHOR]

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]

Abstract The well-mixed morphology of 98-atom Co-Pt clusters is investigated. The global minimal structures of Co m Pt 98- m (m = 1–97) clusters are optimized by adaptive immune optimization algorithm with inner cores (AIOA-IC) method based on the many-body Gupta potential. In Co-poor regions, the clusters are found to adopt face-centered cubic (fcc) and stacking-fault fcc (sf-fcc) motifs while in Co-rich regions, they present icosahedral motifs. Leary tetrahedron (LT) appears to be the dominant motif among all compositions. A T d point group is found in Co 80 Pt 18 cluster, and the construction method for the T d LT is proposed starting from a regular tetrahedron. Moreover, the Co-Pt clusters favor well-mixed pattern except for Co-rich and Co-poor regions and the highest degree of mixing is at Co 55 Pt 43 , which is one of the 14 amorphous motifs but not LT motif. The phenomenon of atomic rearrangement is also reported. Graphical abstract Image 1 Highlights • The well-mixed morphology of 98-atom Co-Pt clusters is investigated. • Leary tetrahedron is the dominant motif, and Co 80 Pt 18 cluster exhibits a T d point group. • Co-Pt clusters favor well-mixed pattern except for Co-rich and Co-poor regions. • The phenomenon of atomic rearrangement is analyzed in Co m Pt 98- m clusters. • Co 55 Pt 43 is considered to be the most stable structure in 98-atom Co-Pt clusters. [ABSTRACT FROM AUTHOR]

Developing environment friendly and low cost methods of fabricating advanced anode materials for lithium ion batteries (LIBs) is very important. Using nori as the precursor, we designed and synthesized the composite of nitrogen-phosphorus-codoped carbon matrixes and cobaltic oxide nanoparticles (N, P-codoped C/Co 3 O 4 ) via hydrolysis of CoCl 2 and calcination method. It is interested that the nori not only provided the dopant of N and P elements but also formed the sponge-like porous carbon matrices which exhibited a large specific surface area as 246.4 m 2 g −1 . Both the dopants and the 3D porous carbon matrix are significantly helpful in improving the electrochemical performance of the product. Used as the anode material of LIB, N, P-codoped C/Co 3 O 4 offered a high reversible specific capacity of 927 mA h g −1 (the theoretical capacity of Co 3 O 4 is 890 mA h g −1 ) after 100 cycles at the current density of 100 mA g −1 and a good rate capability of 454 mA h g −1 at the current density of 1 A g −1 . Thus it is a promising alternative advanced anode material for LIB. In addition, the whole process is green, simple, economical and scalable and the method may be applied to synthesize other N, P-codoped carbon based composites. [ABSTRACT FROM AUTHOR]

FeMnO 3 /Mn 2 O 3 hybrids were prepared by calcinating the Mn 3 [Fe(CN) 6 ] 2 · n H 2 O Prussian Blue Analogues (PBAs) precursor, which involving a room-temperature precipitation of Mn 2+ and K 3 Fe(CN) 6 with or without citric acid as additives. The as-prepared FeMnO 3 inherits the morphology of PBAs and shows a porous structure due to releasing of CO 2 and NO 2 gases in the calcination process in air. FeMnO 3 nanocubes fulling of larger pores mixed with a new morphology of Mn 2 O 3 nanotubes are formed due to the assistance of citric acid (Sample Fe x Mn 2- x O 3 -C). While the single morphology of FeMnO 3 and Mn 2 O 3 nanocubes are obtained without citric acid (Sample Fe x Mn 2- x O 3 ). The Fe x Mn 2-x O 3 -C anode exhibits super Li + storage performance than that of Fe x Mn 2-x O 3 anode, such as higher initial discharge/charge capacities of 1580 and 850 mAh g −1 , and maintain 995 mAh g −1 until 170 cycles at a current density of 200 mA g −1 . The enhanced electrochemical performance is attributed to the inter-connected porous structure and large amount of mesopores of FeMnO 3 nanocubes and Mn 2 O 3 nanotubes, which effectively improved structure stability, reduced the diffusion length of lithium ions and electrons, increased the diffusion coefficient of Li + ion throughout the electrode, and buffered volume expansion during the Li + insertion/extraction processes. These results indicate that the porous FeMnO 3 nanocubes/Mn 2 O 3 nanotubes hybrids can be a promising anode material for high-performance LIBs. [ABSTRACT FROM AUTHOR]

The energy bandgap of semiconductors determines the optical spectrum response of absorber materials, which is one of the vital physical parameters that impact the band alignment of a solar cell's p-n junction. Therefore, the bandgap engineering of absorber materials is essential in that it influences directly the open current voltage and the power conversion efficiency of solar cells. In this paper, the bandgap engineering of Cu 2 Sn(S,Se) 3 (CTSSe) nanocrystals (NCs) were achieved by controlling the ratio of sulfur and selenium in solid solution NCs. The bandgaps of CTSSe NCs were tuned approximately linearly from 1.20 to 1.52 eV by increasing the sulfur and selenium atomic ratio. Moreover, the dense and compact CTSSe absorbers with good crystallization and large grains can be acquired by non-vacuum CTS NCs deposition method. Finally, a typical CTSSe thin film solar cell with power conversion efficiency of 0.89% was acquired according to the traditional structure of thin film solar cells. [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]

Cu 2 ZnSn(S,Se) 4 nanocrystals up to 10 grams per batch were acquired by a large-scale hydrothermal synthetic method. The bandgap engineering of Cu 2 ZnSn(S,Se) 4 nanocrystals was achieved by controlling the ratios of sulfur and selenium atoms in the solid solution nanocrystals. The bandgaps of Cu 2 ZnSn(S,Se) 4 nanocrystals were tuned approximately linearly from 1.29, 1.34, 1.39, 1.44 to 1.52 eV with the increase of sulfur and selenium atomic ratios. Finally, the thermoelectric properties of Cu 2 ZnSn(S,Se) 4 nanocrystals with the various ratios of Se/(S+Se) (0, 0.25, 0.5, 0.75, 1) from 300 to 700 K are elaborated in detail, indicating that the thermal conductivity of Cu 2 ZnSn(S,Se) 4 nanocrystals is lower than that of their bulk counterparts and other binary materials. Besides, the Seebeck coefficients and figure of merit for Cu 2 ZnSn(S,Se) 4 nanocrystals (x = 0.25, 0.5, 0.75) is higher than those of Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 nanocrystals. It is indicated that transferring from bulk materials to the solid solution nanomaterials is an effective way to further enhance the TE performance of CZTS NCs. [ABSTRACT FROM AUTHOR]

SnS nanosheet thin films were prepared by chemical bath deposition in acidic solution, which used tin (II) chloride dihydrate and thioacetamide as precursors of Sn and S, respectively. The influences of pH levels, precursors' mole ratios, deposition times on the physical properties of SnS nanosheet thin films were investigated. The sheet-like morphologies and compositions of as-deposited SnS thin film were characterized by Scanning electron microscope (SEM). X-ray diffraction (XRD), Raman and X-ray photoelectron spectra (XPS) were used to confirm the crystal structures and phase purities of SnS nanosheet thin films. When employed as a photocathode for photo-electrochemical (PEC) solar hydrogen production, the as-deposited SnS nanosheet thin films yielded photocurrent densities of 31.94 μA cm −2 at −0.4 V under illumination of AM 1.5G. After deposition of CdS and Pt layers, the cathodic photocurrent densities of FTO/SnS/CdS/Pt and FTO/annealed SnS/CdS/Pt were improved to 0.572 mA cm −2 and 0.702 mA cm −2 , respectively, which demonstrated the great potential of using earth-abundant SnS for efficient hydrogen production. [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]

SnS:Cu sheet-like thin films were firstly prepared in acidic solution by chemical bath deposition (CBD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterized the morphologies of SnS:Cu thin films. X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS) and Raman spectra examined their phase purities. X-ray photoelectron spectroscopy (XPS) evaluated the valance states of elements in the films. UV-Vis-NIR diffuse reflection spectra determined their bandgaps to be 1.41–1.48 eV. The photoelectrochemical (PEC) measurements indicated that the photocurrent of SnS:Cu (20 at%) thin films had good photo-electronic responses. The fabrication of FTO/SnS:Cu (20% at)/ZnS /TiO 2 /Pt photocathode improved the PEC performance greatly and the photocurrent as high as 1.76 mA/cm2 had been achieved. SnS:Cu thin film solar cells were also fabricated and a power conversion efficiency of 0.3% had been achieved. • SnS:Cu/ZnS PN junction was firstly prepared by chemical bath deposition method. • FTO/SnS:Cu/ZnS/TiO 2 /Pt improved PEC performances of SnS:Cu/ZnS PN junction. • FTO/SnS:Cu/ZnS/ITO/Al thin film solar cells were firstly fabricated. [ABSTRACT FROM AUTHOR]

In this study, hot compression tests of GH690 nickel-based superalloy were carried out on a Gleeble3180 thermo-mechanical simulator with strain rates of 0.1-2s−1 and the temperature range of 950–1200 °C. The true stress-strain curves can reflect the internal relationship between true stress and thermo-mechanical behavior, and the evolution law of internal microstructure. According to the true stress-strain curves obtained from the tests, it can be obtained that temperature and strain rate have a great influence on the hot deformation behavior of GH690 alloy. To study this effect, the Arrhenius-type constitutive equation is used to characterize the relationship between various factors and predict the stress state. The material constants in the Arrhenius-type constitutive equation were determined by linear fitting of the experimental data, where the activation energy Q is about 425 kJ mol−1. Furthermore, the microstructure evolution of GH690 alloy was also analyzed, dynamic recrystallization (DRX) critical strain model, Avrami DRX volume fraction model and DRX grain size model were also established. The constitutive model and DRX dynamic model established in the study are imported into the commercial finite element software Deform-3D to verify the established model. The research results show that the prediction results of the numerical simulation agree well with the test. The combination of the established model and numerical simulation is very useful for studying the hot deformation of the alloy. • The hot deformation behavior of a GH690 alloy is studied. • A physically-based constitutive model is established for the GH690 alloy. • The DRX kinetics models are established for the GH690 alloy. • DRX results of the Finite Element Method (FEM) are found to closely match those from the experiment. [ABSTRACT FROM AUTHOR]

The development of novel phosphors with stable and efficient green and red up-conversion (UC) emission is important for many applications such as fluorescent labeling, color display and anticounterfeiting. In this work, we report a stable and efficient green and red up-converter of LiYF 4 :Yb3+,Ho3+ octahedrons obtained by modified hydrothermal method. The UC emission and luminescence decays of LiYF 4 :Yb3+,Ho3+ with various Yb3+ and Ho3+ ion concentrations were studied systematically under 976 nm LD excitation. The Yb3+ and Ho3+ ion concentrations were optimized to be 20 mol% and 1 mol% respectively, for efficient green and red UC emissions. LiYF 4 :Yb3+,Ho3+ presents not only controlled morphology of monodisperse octahedrons with length of ∼20 μm and width of ∼10 μm, but also performs efficient green and red UC emissions, which is about four times stronger than that of β-NaGdF 4 : 20 Yb3+,0.5Ho3+ (NaGdF 4 : 20 Yb3+,0.5Ho3+). More importantly, the stable UC emission with variation of green intensity ratio ΔG% (G% = I 520-570nm /I 500-700nm , ΔG%= (G%) max -(G%) min) and red intensity ratio ΔR% (R% = I 625-685nm /I 500-700nm , ΔR%= (R%) max -(R%) min) < 1% was found over 976 nm LD excitation power density (PD) ranging from 1.0 to 5.6 W/cm2. Whereas, their variations of ∼6% and 25% are observed at the same excitation PD for NaGdF 4 :20 Yb3+,0.5Ho3+ and commercial β-NaYF 4 :20 Yb3+,2Er3+ (NaYF 4 : 20 Yb3+,2Er3+), respectively. The mechanism of green and red UC emissions in LiYF 4 : Yb3+,Ho3+ as a consequence of energy transfer processes has been briefly discussed taking into account the UC emission kinetics. The highly stable intensity ratio of G% and R% combined with the efficient green UC color hints the potential application of LiYF 4 : Yb3+,Ho3+ in fluorescent labeling and color display. Image 1 [ABSTRACT FROM AUTHOR]

In this paper, SnS nanorods were first prepared in an acidic solution by adjusting the amounts of tri-sodium citrate at room temperature using template-free electro-deposition method. The morphological characteristics and photoelectrochemical (PEC) properties of SnS nanorods thin films were investigated. The phase purity properties of deposited SnS thin films were analyzed by X-ray diffraction (XRD), energy disperse spectroscopy (EDS) and Raman spectra measurements. The morphological characteristics of SnS nanorods were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The band-gaps of SnS thin films were confirmed by UV–Vis–NIR diffuse reflectance spectrum. The PEC characterizations indicated that the photocurrent density of SnS nanorods thin films was about 46 μA/cm2 and the maximum IPCE value of SnS nanorods thin films was 9.3%. The fabrication of FTO/SnS (nanorods)/CdS/TiO 2 /Pt photoelectrode improved the PEC performances of SnS nanorods thin films greatly. The photocurrent density of FTO/SnS (nanorods)/CdS/TiO 2 /Pt reached 0.59 mA/cm2, and the maximum IPCE value of FTO/SnS (nanorods)/CdS/TiO 2 /Pt achieved 27.1%. Image 1 • Template-free electrodeposited SnS nanorods were firstly reported. • The amount of tri-sodium citrate determines the morphological evolution of SnS nanorods. • PEC properties of SnS nanorods were greatly enhanced by FTO/SnS/CdS/TiO 2 /Pt photoelectrode. [ABSTRACT FROM AUTHOR]