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In order to explore the morphology and improved electrochemical performance of diamond-like carbon (DLC) deposited on SnSb/C nanofiber derived from different precursors by the atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) technology. SnCl4•5H2O/SbCl3 (I), Sn(CH3COO)2/Sb(CH3COO)3 (II) were used as SnSb precursors, respectively, the SnSb/C nanofiber membranes were prepared by electrospinning and carbonization, and then DLC was deposited on different SnSb/C nanofibers to obtain SnSb/C/DLC nanofibers. It is shown that the densified and irregular cubic-like DLC nanoparticles were deposited on SnSb/C (I) nanofibers. While on the SnSb/C(II) nanofibers, DLC nanoparticles exhibited as sparse and spherical. Meanwhile, both SnSb/C/DLC nanofibers have good structural stability, especially higher sp3/sp2 ratios DLC was shown in the SnSb/C/DLC (I) nanofiber than that of SnSb/C/DLC (II) one. By comparison, SnSb/C/DLC(I) nanofibers have excellent electrochemical performance, the capacity retention is 69.33% after 100 cycles, and the capacity retention rate from 20 to 100 cycles is 109.24%. This reveals that DLC materials with higher C–C content and uniform distribution have a positive effect on the aspect of inhibiting SnSb alloys volume expansion. [ABSTRACT FROM AUTHOR]

Recently, a new layered-ternary compound V2SnC was successfully synthesised by reacting V, Sn, and C powder mixture at 1000°C. Its space group was identified as P63/mmc. In this work, the structural, mechanical properties, and thermal conductivity of this new layered-ternary compound have been studied under pressure up to 100 GPa by density functional theory. The calculated lattice parameters and cell volume of V2SnC at the ground state are in good coincidence with the experimental values. With the increase of pressure, the a-axis of V2SnC crystal structure has greater compressibility than the c-axis. In addition, the calculated results of elastic constants and phonon dispersion curves indicated that V2SnC is mechanically and dynamically stable from 0 to 100 GPa. Furthermore, the influence of pressure on bulk modulus B, shear modulus G, aggregate acoustic velocities vm, Debye temperature ΘD, Poisson's ratio σ, and Grüneisen parameter γ are systematically investigated. Meanwhile, the elastic anisotropy of V2SnC under external pressure is also studied for the first time. Finally, the minimum thermal conductivity of V2SnC under external pressure is further studied. The results show that this material has good thermal insulation performance. [ABSTRACT FROM AUTHOR]

Recently, Wang et al. [Nat. Commun. 10 (2019) 2284] report a new compound, Ti2InB2, a stable boron-based ternary phase in the Ti-In-B system. This predicted compound is successfully synthesised using a solid-state reaction route and its space group is confirmed as P 6 ¯ m 2 (No. 187). In this work, the structural stability, mechanical properties, and thermal conductivity of the new hexagonal ternary phase Ti2InB2 under pressure up to 100 GPa have been carried out with first-principles calculations based on density functional theory. Our calculated lattice parameters in the ground state are consistent well with the theoretical prediction data. The calculations of elastic constants and phonon dispersion curves indicate that Ti2InB2 is mechanically and dynamically stable at least up to 100 GPa. Moreover, the pressure dependent elastic properties, such as bulk modulus B, shear modulus G, transverse sound velocity vt, longitudinal sound velocity vl, and Debye temperature Θ, are successfully obtained. It is found that Ti2InB2 behave in brittle manner under pressure up to 100 GPa. Meanwhile, the anisotropy of the directional linear compressibility and the Young's modulus under pressure are also analysed for the first time. Finally, the minimum thermal conductivity of Ti2InB2 under different pressures are further evaluated by using both Clark's model and Cahill's model. The results show that Ti2InB2 exhibits relatively low thermal conductivity in the ground state and is suitable to be used as thermal insulating materials. [ABSTRACT FROM AUTHOR]

The structural, elastic, and electronic properties of SrZrN2 under pressure up to 100 GPa have been carried out with first-principles calculations based on density functional theory. The calculated lattice parameters at 0 GPa and 0 K by using the GGA-PW91-ultrasoft method are in good agreement with the available experimental data and other previous theoretical calculations. The pressure dependence of the elastic constants and the elastic-dependent properties of SrZrN2, such as bulk modulus B, shear modulus G, Young's modulus E, Debye temperature Θ, shear and longitudinal wave velocity VS and VL, are also successfully obtained. It is found that all elastic constants increase monotonically with pressure. When the pressure increases up to 140 GPa, the obtained elastic constants do not satisfy the mechanical stability criteria and a phase transition might has occurred. Moreover, the anisotropy of the directional-dependent Young's modulus and the linear compressibility under different pressures are analysed for the first time. Finally, the pressure dependence of the total and partial densities of states and the bonding property of SrZrN2 are also investigated. [ABSTRACT FROM AUTHOR]

Two complexes constructed from aromatic acid and /V-heterocyclic ligands have been synthesized by hydrothermal reaction: [Pb(cipt)(NDC)]n (1) [cipt = 2-(3-chlorophenyl)-lH-imidazo [4,5-F][L, 10]phenanthroline, NDC = naphthalene-1,4-dicarboxylic acid] and [Pb(ipm)(BDC)2]n (2) [BDC = terephthalic acid, ipm=5-(lH-imidazo[4,5-f][l, 10]phenanthrolin-2-yl)-2-methoxyphenol], Single-crystal X-ray analysis shows that 1 exhibits an interesting arm-shaped chain structure. 1-D ladder chain structure is formed by N-H-0 bonding interactions and further into a 2-D network by N-H...O hydrogen bonds and interchain n-n stacking interactions. Complex 2 shows a 2-D butterfly wings structure, which has been rarely reported. The structure in 2 has intermolecular N-H-0 interactions, which help in construction of the 3-D framework. In 1, the coordination sphere of Pb(II) is hemi-directed, whereas the Pb(II) geometry in 2 is holo-directed. The solid-state fluorescence spectra of 1 and 2 are also investigated, as well as the ligands cipt and ipm. [ABSTRACT FROM AUTHOR]

Here, we describe the first complete mitochondrial genome of Yao silkworm, a unique silkworm resource native at Guangxi, China. This circular molecule is 15,656 bp long and contains the typical set of 37 genes (13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes) and one non-coding A + T-rich region of 494 bp long. The genome organization and gene arrangement are identical to those observed in all available Bombyx mori strains. The phylogenetic tree inferred from Bayesian inference provides a molecular evidence that Yao silkworm belongs to the domestic silkworm (B. mori), rather than a novel silkworm species. [ABSTRACT FROM AUTHOR]