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Far red-emitting Mn4+-activated oxide phosphor based on the substitution of Mn4+ for Sb5+ in the lattice of Sr3NaSbO6 (SNSO) was prepared via solid state reaction process. The crystal structure of the host was carefully discussed and studied. The resultant phosphors were characterized by X-ray powder diffraction, fluorescence spectra, ultraviolet-visible diffuse reflectance spectra, temperature-dependent emission spectra (298–548 K), luminescence decay curves and electroluminescence spectra. Excitation and emission spectra indicated that the sample had a wide excitation band in UV(250–400 nm) and exhibited the strong emission band centered at 695 nm. The band structure for SNSO was calculated based on the density functional theory, and the bandgap value of SNSO host is ∼2.92 eV. In addition, the mechanism of quenching concentration and energy-transfer of SNSO:Mn4+ were explored and analyzed in detail through calculation. The UV–Vis diffusion reflectance spectra demonstrated that samples had strong absorption (200–550 nm) in the ultraviolet(UV) and near-ultraviolet(NUV) region. The thermal stability of SNSO:Mn4+ was excellent (I423K/I273K = 39.84%). The internal quantum efficiency is 56.2%. In brief, the prepared phosphors had potential application in indoor plant growth as a LED lamp.

We report a joint experimental and theoretical investigation on the structures and bonding of a series of di-niobium gold clusters, Nb2Aux− (x = 2–5), using photoelectron spectroscopy and density functional calculations. Well-resolved spectral features are observed for the Nb2Aux− clusters at different photon energies. Global minimum searches coupled with density functional calculations are performed to find the low-lying structures of the bimetallic clusters. Vertical detachment energies are calculated and compared with the experimental spectra to determine the global minimum structures. The Nb2Aux− (x = 2–5) clusters are found to feature a multiply-bonded Nb2 dimer coordinated equatorially by the Au atoms with Dxh symmetries for x = 2–5, respectively. Each Au atom interacts with the Nb2 dimer via a 3-center delocalized σ bond, while there are no Au…Au interactions. The Nb Nb bond length is found to increase as the number of gold atoms increases in the Nb2Aux− (x = 2–5) clusters, as a result of the decrease of the bond order for the Nb2 moiety from x = 2 to 5.

Polycrystalline (Pb0.94La0.04) Zr0.6Ti0.4O3 thin films were fabricated by a sol–gel method on the Pt (111)/Ti/SiO2/Si (100) substrates. Results from X-ray diffraction reveal that a strain-induced low-asymmetry monoclinic (MB) phase exists in all the films as compared with its powder counterpart. Also, films exhibit a simple trend of pyrolysis-sensitive (100)-orient growth. Good piezoelectric longitudinal coefficient values are obtained in the films where a maximum around 130 pm/V is reached for the film pyrolyzing at 425 °C. These findings suggest that combined contributions of monoclinic phase and (100)-preferred orientation type as well as good surface quality will account for excellent piezoelectric properties for ferroelectric films.

We report the observation of two Fe-doped boron clusters with wheel-type structures, containing an octa-coordinate ( C 8 v -Fe©B 8 − ) and a nona-coordinate ( D 9 h -Fe©B 9 − ) Fe atom. The clusters were produced in a laser vaporization supersonic molecular beam and characterized by combined photoelectron spectroscopy and ab initio studies. Chemical bonding analyses revealed that in the ground state both clusters are doubly (σ + π) aromatic and that the iron atom interacts with the peripheral boron ring exclusively through delocalized bonds. These findings provide further support to the design principle for metal-doped boron clusters with highly symmetric molecular wheel-type structures.

Electronic structure and mechanical properties of cubic crystallographic structures with point defects in Al-based alloys are investigated using the first-principles calculations. Equilibrium structural parameters and mechanical parameters such as bulk modulus, shear modulus, Young's modulus, Poisson's ratio and anisotropy are calculated and agreed well with experimental values. Effects of point defects on the electronic structures and mechanical properties of such cubic phases are further analyzed and discussed in view of the charge density and the density of states.

First-principles calculations are performed to study on alloying stability, elastic properties, ductility and electronic properties of AlCu 2 X (X = Ti, Mn, Zr, or Hf) intermetallics within the generalized gradient approximation. The obtained lattice parameters for all intermetallics considered are very close to the corresponding experimental values. The calculated cohesive energy ( E coh ) and formation energy (Δ H ) show that the AlCu 2 Zr crystal structure is more stable, and the alloying ability of AlCu 2 Zr is also stronger. The calculated density of states of these phases indicates that the highest structural stability of AlCu 2 Zr is attributed to the lower value of the DOS at the Fermi level, i.e., N ( E F ). The elastic constants C ij of these phases were calculated, and the bulk modulus B , shear modulus G were derived from the elastic constants. The calculations on the ratio of bulk modulus to shear modulus reveal that the ductility of AlCu 2 Zr is better than AlCu 2 Mn, AlCu 2 Ti and AlCu 2 Hf. In addition, the work functions (WF) and surface energies of (1 0 0) and (1 1 0) surfaces of AlCu 2 X intermetallics are also investigated. For the four AlCu 2 X intermetallics, the work function of (1 1 0) surface is higher than that of (1 0 0), and the surface with a higher work function is prone to have a lower surface energy. Furthermore, both shear modulus and WF decrease, and changes in both WF and bulk modulus of the four intermetallics have a similar trend, except for AlCu 2 Ti and AlCu 2 Hf. It is also revealed that with the increase of WF, the ductility decrease, which is attributed to a change in the nature of the atomic bonding or in the electronic structure induced by the alloying.

CaCu3Ti4O12 powder was prepared by sol-gel technique, and the CaCu3Ti4O12 composites were sintered at 1 000°C for different time after cold pressing with the same pressure and time. The results exhibit that the grain size is affected by the pressure and sintering time. The impedance spectrum measurement results show that both the dielectric constant and dielectric loss have a weak frequency dependence over large frequency region of 50 Hz to 100 kHz, and not only does the dielectric loss decrease but also the dielectric constant remains high sufficiently. The most suitable sintering time is 6 h.

Peripherally tetraimido-substituted phthalocyaninato zinc compounds 1–3 were synthesized through the reaction of tetraamino-substituted phthalocyaninato zinc with 4-Br-1,8-naphthalic anhydride, 4-hexahydropyridine-1,8-naphthalic anhydride and 4-morpholine-1,8-naphthalic anhydride, respectively. The compounds were characterized by MS, 1 H NMR, UV–vis, IR and elemental analysis, the results of which were consistent with the proposed structures. The effects of substitutes, acid/base and solvents on the UV–vis spectra of the new complexes were discussed in detail.

Fe–N thin films were prepared by direction-current magnetron sputtering with different process parameters. The surface morphology and fractal dimension of the films have been studied using atomic force microscopy and small angle X-ray scattering techniques. The results indicate that the surfaces of thin films exhibit an obviously self-affine fractal characteristic, and the fractal dimension is greatly affected by the N 2 /Ar flow rate ratio. When the N 2 /Ar flow rate ratio is less than 1/6, the film growth follows the KPZ growth model. Contrarily, the growth mechanism of the film is agreement with the DLCA model.

Objective To study whether a combination of berberine and letrozole results in higher live births than letrozole alone in infertile women with polycystic ovary syndrome (PCOS). Design A multicenter randomized double-blinded placebo-controlled trial. Setting Reproductive and developmental network sites. Patient(s) Eligible women had PCOS as defined by the Rotterdam criteria. We enrolled 644 participants randomized 1:1:1 among letrozole, berberine, and combination groups. Interventions(s) Berberine or berberine placebo were administrated orally at a daily dose of 1.5 g for up to 6 months. Patients received an initial dose of 2.5 mg letrozole or placebo on days 3–7 of the first three treatment cycles. This dose was increased to 5 mg on the last three cycles if not pregnant. Main Outcomes Measure(s) Cumulative live births. Results The cumulative live births were similar between the letrozole and combination groups after treatment (36% and 34%), and were superior to those in the berberine group (22%). Likely, conception, pregnancy, and ovulation rates were similar between the letrozole and combination groups, and these were significantly higher than in the berberine group. There was one twin birth in the letrozole group, three twin births in the combination group, and none in the berberine group. Conclusion(s) Berberine did not add fecundity in PCOS when used in combination with the new ovulation agent letrozole. Clinical Trial Registration Number ChiCTR-TRC-09000376 (http://apps.who.int/trialsearch/).