Search

High efficient lead halide perovskites with wide-color gamut properties have emerged as new candidates for backlight displays. However, the toxicity of lead and the instability of halide perovskites greatly limit their practical applications. Herein, the luminescent powders of [(CH3)4N]2MnBr4 and [(CH3)4N]MnBr3 were synthesized via a simple yet robust solvent evaporation method. [(CH3)4N]2MnBr4 with tetrahedral coordination Mn2+ and [(CH3)4N]MnBr3 with octahedral coordination Mn2+ show green at 517 nm and red emission peaks at 620 nm, respectively, originating from the 4T1-6A1 transition of Mn2+. To enhance optical of manganese halide via effective alloying, Zn2+-doped [(CH3)4N]2MnBr4 was successfully prepared, and the quantum efficiency of [(CH3)4N]2Mn0.6Zn0.4Br4 was as high as 65%. Furthermore, [(CH3)4N]2Mn0.6Zn0.4Br4 exhibits better optical and thermal stability compared to [(CH3)4N]2MnBr4. [(CH3)4N]2Mn0.6Zn0.4Br4@CsPbBr1.2I1.8 light conversion films with different green-to-red ratios are placed in backlight display devices, and their color gamut exceeds 106% of the National Television Standards Committee (NTSC) 1953 standard, which is superior to the currently reported Mn-based perovskite. This work broadly shows that the [(CH3)4N]2Mn0.6Zn0.4Br4 will provide effective route to fabricate stable and high-performance lead-free liquid crystal displays. [ABSTRACT FROM AUTHOR]

Perovskite materials have received extensive attention as optical gain media. However, it is tough to realize lasing using such materials on account of the unstable structure of MAPbI3/CsPbI3 nanocrystals (NCs), and the propensity for mixed-halogen perovskites to undergo phase decomposition into bromine-rich and iodide-rich regions under intense laser irradiation. To solve this issue, we fabricated CsPbX3 (X = Br, I) NCs, which were embedded into a glassy matrix with high stability. In addition, by doping Br− ions into the CsPbI3 NCs to partially replace I− ions, the optical efficiency and the optical gain properties were found to be significantly improved. Here, under 800 nm pulse laser excitation, red random lasing was realized with the assistance of such anion modulation. Moreover, we demonstrate that the perovskite NCs glasses (PNG) show strong water stability after immersion in water for one week, seeding a promise for application in high-definition (HD) displays and photonic devices. [ABSTRACT FROM AUTHOR]

In recent years, metal oxide hole transporting layers (HTLs) have been commonly used in inverted planar perovskite solar cells. Due to high optical transmittance, better long-term stability, and suitable energy band characteristics, NiOx HTLs have been intensively studied. The NiOx materials prepared by solution-combustion method with characteristics of self-energy generation and exothermic reaction have received much attention, which significantly reduces the reaction temperature compared with the traditional sol–gel methods. In this paper, a NiOx film with better conductivity and enhanced carrier extraction was obtained by adjusting the fuel concentration in the nickel oxide precursor solution. It was also confirmed that perovskite film was improved with larger grain size and reduced trap-state densities. As a consequence, by using the 10 ul/ml optimal concentration of acetylacetone in the NiOx precursor solution, the inverted planar perovskite solar cells achieved a maximum power conversion efficiency of 14.37%. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: ATPase copper transporting α (ATP7A), also known as Menkes disease protein, is a P-type ATPase that transports copper across cell membranes. The critical role of ATP7A-mediated copper homeostasis has been well recognised in various organs, such as the intestine, macrophages and the nervous system. However, the importance of adipocyte ATP7A-mediated copper homeostasis on fat metabolism is not well understood. Here, we sought to reveal the contribution of adipose ATP7A to whole-body fat metabolism in mice. Methods: We generated adipocyte-specific Atp7a-knockout (ASKO) mice using the Cre/loxP system, with Cre expression driven by the adiponectin promoter. ASKO mice and littermate control mice were aged on a chow diet or fed with a high-fat diet (HFD); body weight, fat mass, and glucose and insulin metabolism were analysed. Histological analysis, transmission electron microscopy and RNA-sequencing (RNA-Seq) analysis of white adipose tissue (WAT) were used to understand the physiological and molecular changes associated with loss of copper homeostasis in adipocytes. Results: Significantly increased copper concentrations were observed in adipose tissues of ASKO mice compared with control mice. Aged or HFD-fed ASKO mice manifested a lipoatrophic phenotype characterised by a progressive generalised loss of WAT. Dysfunction of adipose tissues in these ASKO mice was confirmed by decreased levels of both serum leptin and adiponectin and increased levels of triacylglycerol and insulin. Systemic metabolism was also impaired in these mice, as evidenced by a pronounced glucose intolerance, insulin resistance and hepatic steatosis. Moreover, we demonstrate a significant induction of lipolysis and DNA-damage signalling pathways in gonadal WAT from aged and HFD-fed ASKO mice. In vitro studies suggest that copper overload is responsible for increased lipolysis and DNA damage. Conclusions/interpretation: Our results show a previously unappreciated role of adipocyte Atp7a in the regulation of ageing-related metabolic disease and identify new metallophysiologies in whole-body fat metabolism. Data availability: The datasets generated during the current study are available in the Genome Sequence Archive in BIG Data Center, Beijing Institute of Genomics (BIG), Chinese Academy of Sciences, under accession number CRA001769 (http://bigd.big.ac.cn/gsa). [ABSTRACT FROM AUTHOR]

In recent years, numerous efforts have been made to develop single-phased white light-emitting phosphors for the near-UV region to solve problems of color reabsorption and ratio regulation between different phosphors. In this work, we have designed Bi3+- and Eu3+-codoped single-phased Gd2MgTiO6 phosphors to achieve tunable white light emission based on multi-luminescence center energy transfer. The structural analysis showed that all the samples were crystallized as a monoclinic double perovskite with the P21/n symmetry space group (No. 14), with HRTEM images showing clear lattice fringes between the lattice planes. The single Bi3+-doped Gd2MgTiO6 sample exhibits two obvious emission peaks at 417 and 508 nm, which correspond to a characteristic 3P1 → 1S0 transition for the Bi3+ ions under near-UV excitation due to two types of Bi3+ emission centers, with their relative emission intensity depending closely on the value of the excitation wavelength. In this case, a suitable choice of excitation wavelength can achieve tunable emission for Gd2MgTiO6: Bi3+ between blue and green. Eu3+ is codoped into Gd2MgTiO6 as a red emission component and shows sharp emission lines that correspond to the characteristic 5D0 → 7FJ (J = 1, 2, 3, and 4) transitions of Eu3+ ions. Energy transfer in Gd2MgTiO6: Bi3+, Eu3+ has been confirmed by the electric dipole-dipole (d-d) interaction from Bi3+ to Eu3+. Our experiments show that it is straightforward to create tunable white light emission by adjusting the excitation scheme and Eu3+ concentration. Moreover, a schematic for the energy transfer mechanism and simplified spectral levels based on Bi3+ and Eu3+ ions has also been established. [ABSTRACT FROM AUTHOR]

Various luminescent carbon materials are artificially synthesized and as admirable fluorescent materials because of the increased research of carbon nanodots (CDs). Herein, a novel solvent-dependent red CDs (rCDs) is introduced through solvothermal method. The as-prepared rCDs remain benzene structure and possess abundant surface function groups that endow them well solubility in various solvents. Furthermore, multicolor luminescence are observed when rCDs are dissolved in different solvents, and the emission wavelength of these materials can be well-tuned from 475 to 624 nm, which presents intensity solvent-dependent properties. Red luminescence carbon phosphors are successfully synthesized by mix rCDs with silica powder. Finally, warm white light emitting diodes (WLEDs) are constructed using rCDs powder with Ce3+: YAG single crystal and blue GaN chips. The results demonstrate that the rCDs can act as red component to modify the correlated color temperature (CCT) and the color rendering index (CRI) of WLEDs. [ABSTRACT FROM AUTHOR]

Herein, novel composite glass materials are synthesized by a facile sol-gel approach accompanied with a controlled atmosphere, in which inexpensive iron oxide nanoparticles (NPs) are introduced into sodium borosilicate glasses host. By defining temperature and time limits, two iron oxide NPs with different chemical valence (FeO NPs and FeO NPs) were produced in the glass host. The incorporation of iron oxide NPs in a sodium borosilicate glasses matrix vouchsafe the obtained glasses excellent nonlinear optical response. Thus, the Z-scan method using a ultrafast femtosecond laser pulse as fast as 190 fs was employed to evaluate the nonlinear optical feature of as-derived glasses, exhibiting self-focusing effect with reverse saturable absorption. In addition, we have added the new physics analysis of the mechanism on the nonlinear effects in the paper. The obtained results imply that these glass materials are promising candidates for the future development of ultrafast nonlinear devices. [ABSTRACT FROM AUTHOR]

The spherical shape copper oxide (CuO) quantum dots (QDs) were successfully fabricated via copper basic calcium sodium borosilicate (NaO-CaO-BO-SiO) precursor obtained with a facile sol-gel technique. The microstructural analysis of doped QDs are systemically characterized, such as transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and X-ray photo-electron spectroscopy. And the results reveal that the CuO QDs with the small size are well dispersed doped in sodium calcium borosilicate glass. Remarkably, the CuO glass materials exhibit the good third-order optical nonlinear susceptibility χ (1.379 × 10 esu), which was investigated by femto-second Z-scan technique at the wavelength of 1550 nm, pulse duration of 50 fs, repetition rate of 50 MHz. The glass hybrids displayed a reverse saturable absorption and self-focusing refraction performance. And the mechanism to explain the third-order nonlinearity of CuO glass may be predominantly originated from the surface plasmon resonance effect, the quantum confinement effect and partly from the thermal effect. Besides, it is interesting that the glass hybrids have significant nonlinear absorption effects that endow the material to the potential value of the application of optical limiting device. [ABSTRACT FROM AUTHOR]

To relieve the issues of high correlated color temperature and low color rendering index, it is urgent to develop an inorganic color converter materials with both red- and yellow-emission to replace the conventional organic resin/silicon-based color converter and acquire warm white light-emitting diodes (WLEDs). In our work, transparent glass-ceramics (GCs) containing Ce:YAlO (Ce:YAG) yellow phosphors and Eu ions are successfully fabricated by using low temperature co-sintering technique. And then the microstructure and luminescence properties of the GC are investigated in detail. Importantly, the impact of Ce:YAG phosphors concentration, Eu ions concentration, co-sintering time and the GC thickness on optical performances are also systematically demonstrated. Impressively, the as-fabricated samples exhibit an efficient red emission at 611 nm owing to the D→F transition of Eu. Subsequently, the temperature-dependent luminescence and thermal quenching is also investigated. Finally, the constructed WLEDs show an optimal luminous efficacy of 120.85 lm/W, a color rendering index of 70.2 and a correlated color temperature of 5267 K. All the results indicate that the as-fabricated GC would have potential practical applications in high-power WLEDs. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (Au NPs) doped monolithic and transparent sodium borosilicate glass has been synthesized by both sol-gel and atmosphere control heat treatment methods. Fourier transform infrared (FTIR) spectra in the wavenumber range of 400 to 4000 cm were applied to collect variation information of surface groups of the samples in the sintering process. The microstructure of Au NPs in the glass was characterized by means of X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). Meanwhile, the linear optical properties of the glass were analyzed by UV-vis spectrometer between the wavelength of 300 and 1000 nm, and a broad absorption band around 600 nm was observed. The third-order nonlinear optical properties of the glass were investigated by using Z-scan technique at the wavelength of 800 nm, pulse duration of 190 fs, and repetition rate of 20 Hz. The glass showed saturable absorption and self-focusing nonlinear refraction, and the optical nonlinear susceptibility χ was estimated to be 1.7 × 10 esu, with the single-pulse energy of 1 μJ. [ABSTRACT FROM AUTHOR]

To prepare pearlyescent pigment of micron glass/nano-FeO by co-precipitation method, the micron dimension glass as substrate must be eroded by sodium hydroxide solution and hydrofluoric acid for appropriate time so as to obtain more 'growing points' for 'crystal seed point' of FeO. The effects of eroding time of sodium hydroxide solution, eroding time of hydrofluoric acid and the reaction temperature on coating layer of micron glass/nano-FeO were investigated. The results showed when the micro glass as a substrate would be eroded by 0.5 mol/L sodium hydroxide solution for 20 min and then by 0.1 mol/L hydrofluoric acid for 8 min, the FeO coated layer displays uniform tightly packed nano-scales granular shape, the particle size can be estimated ≈30 nm. The samples were characterized by XRD, HRSEM, XPS, VSM, FT-IR and color measurement. [ABSTRACT FROM AUTHOR]

The 2-DE/MS-based proteomics approach was used to investigate the differences of porcine skeletal muscle, and ATP5B was identified as one differential expression protein. In the present study, ATP5B gene was further cloned by RT-PCR, the sequence was analyzed using the bioinformatics method, and the mRNA expression was detected by qRT-PCR. Sequence analysis showed that the porcine ATP5B gene contains an ORF encoding 528-amino-acid residues with 49 and 166 nucleotides in the 5′ and 3′ UTRs, respectively. The mRNA of ATP5B was widely expressed in all 14 tissues tested, but especially highly expressed in parorchis and fat. The expression pattern of ATP5B was similar in Large White and Meishan breeds, showing that the expression was upregulated by 3 days after birth and downregulated during postnatal development of skeletal muscle. Comparing the two breeds, the mRNA abundance of ATP5B in Large White was more highly expressed than in Meishan at all developmental stages ( P < 0.05). Moreover, a synonymous mutation, G75A in exon 8, was identified and association analysis with the traits of meat quality showed that it was significantly associated with the RLF, FMP, IFR, IMF, and IMW ( P < 0.05). These results suggested that ATP5B probably plays a key role in porcine skeletal muscle development and may provide further insight into the molecular mechanisms responsible for breed-specific differences in meat quality. [ABSTRACT FROM AUTHOR]

Well dispersed FeO nanoparticles were synthesized at 180°C by sol-vothermal method, using iron (III) acetylacetonate as iron source and poly-vinilpyrrolidone (PVP) as special surfactant. The factors affecting reaction system, such as reaction temperature and time, the amount of iron source and surfactant are discussed. The synthesized FeO particles show excellent saturation magnetization and super-paramagnetic properties, demonstrating their potential applicability in magnetic nanodevices and bio-medicine. [ABSTRACT FROM AUTHOR]

Experiments on preparation of mica/FeO pearlescent pigment were performed to discuss influences of several crucial parameters on final products. The samples were characterized by XRD, HRSEM, FTIR and color measurement, the content of FeO on the mica surface was also analyzed by XPS. It was found that the smoothness, compactness and colour deepness of the coating were influenced by different pH values and temperatures. The optimum preparation parameters of mica/FeO pearlescent pigment were obtained: the value of pH ≥ 9.2; the concentration of sodium hydroxide was 0.5 mol/l; the concentration ratio of Fe to Fe was 1.6 : 1; the velocity of magnetic stirring was 138 ≤ v ≤ 151 r/min; reaction temperature was 70-80°C; calcination temperature was 350°C and calcination time was 3 h. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles (Fe3O4) were synthesized by the solvothermal method using FeCl3 · 6H2O and ethylene glycol as a reactant. Powder X-ray diffraction, FT-IR, TEM, SEM, and VSM were used to characterize the magnetic particles. The reacting factors, such as reacting time, the concentration of iron source and surfactant, especially the effect of NaAc · 3H2O, were studied. The results indicated that NaAc · 3H2O plays the role not only as a dispersant but also a structure-directing agent. The synthesized Fe3O4 particles showed excellent magnetic property, which made them have potential for application in magnetic nanodevices and biomedicine. [ABSTRACT FROM AUTHOR]

Monoclinic-FeOOH with: a = 0.9981 nm, b = 0.2948 nm, n = 1.0485 nm, β = 92.26° was synthesized by the hydrolysis of FeCl3 · 6H2O in micro emulsion including NP-4, octane, water. In this paper, the various morphology and size of the nano particles under different conditions are discussed, and it is found that the optimum conditions for synthesizing acicular β-FeOOH is that R = 6.0, [Fe3+] = 0.02 mol/L within the pH range 1.6–2.0. [ABSTRACT FROM AUTHOR]