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Previous research has demonstrated that distorted images caused by turbid media can be reconstructed by turbid lens imaging (TLI) method. In this way, it’s critical to accurately obtain the transmission matrix (TM) of turbid media. In this letter, we propose an improved method which is still based on Hilbert transform to get the transmission matrices, but it will use four images for each transmission matrix element to eliminate the influence of speckle intensity variation. In addition, a Hanning window filter is introduced to reduce the white Gaussian noise of original images to improve the result of TLI method. [ABSTRACT FROM AUTHOR]

Comparisons were made among the evaluation models of fatigue crack growth in various codes, standards, and guidelines, to illustrate the significance of transition point in accuracy. A new bilinear model was established with transition point and fatigue threshold fully considered, and was found more accurate than existing codes and standards for evaluation of fatigue crack growth behavior in both Paris and near-threshold regimes. • Conservativeness in existing codes and standards for fatigue crack growth assessment was compared. • Transition point in fatigue crack growth was found significant in assessment accuracy. • A new bilinear model for fatigue crack growth evaluation was developed. [ABSTRACT FROM AUTHOR]

• m -ln C relationship was correlated well with transition behavior of FCG curve. • A master curve for transition behavior of FCG curve was found. • Crack closure was considered for transition point modeling for the first time. • A new model for transition point prediction was established. The transition behavior of fatigue crack growth was investigated using data from a CrNiMoV steel welded joint. The m -ln C was linearly correlated under a given stress ratio in both Paris and near-threshold regimes, where the coordinate of transition point was found as slope and intercept of m -ln C relationship. All m -ln C curves tended to pass through one fixed point, (m 0 , lnC 0), and a master curve for transition point was determined. A new model for transition point prediction was established which had significance in accurate fatigue life assessment on the basis of the bilinear approach. [ABSTRACT FROM AUTHOR]

• Ultrapure green emissions of glass-stabilized CsPb(Br/I) 3 PeQDs are fabricated. • Quantum yields of CsPb(Br/I) 3 @glass composites are highly dependent on halogen content. • The emissive profiles and FWHMs can be well modified by varying Br-to-I ratio in glass. • The issues of instability, adverse anion-exchange and phase separation of colloidal PeQDs can be solved by glass protection. • Prototypical white LEDs are constructed and applied in backlit display, covering up 92% color gamut of Rec. 2020 standard. CsPbX 3 (X = Cl, Br, I) perovskite quantum dots (PeQDs) have potential application in backlit display. However, they generally suffer from instability and shortage of ultrapure tunable green emissions owing to halogen phase separation. This work reports the realization of elaborately tunable green emissions in glass-protected CsPb(Br/I) 3 PeQDs, which show the advantage of superior long-term stability and enable them to find promising application in ultra-high definition televisions. CsPbX 3 @glass composites are fabricated by a facile in-situ glass crystallization strategy and their emissions within the spectral range of 506–532 nm along with narrow full width at half maximum (FWHM) of ~21 nm can be well modified by simply varying Br-to-I ratio in precursor glass. Benefited from the protection of tight glass network, CsPbX 3 @glass retains 90% luminescence after immersing in water for one month, shows no any loss of luminescence after irradiation by 450 nm LED light and prevents anion-exchange and phase separation completely. As a proof-of-concept experiment, CsPbX 3 @glass-based on-chip white LED devices are constructed and applied in backlit display, covering up 123% and 92% color gamut of NTSC and Rec. 2020 standards in the CIE 1931 color space, respectively. [ABSTRACT FROM AUTHOR]

Selenization is a key process to prepare Cu 2 ZnSnS x Se 4-x (CZTSSe) thin films from sulfide for high efficient solar cell. To explore the effect of annealing atmosphere on the substitution of S by Se in Cu 2 ZnSnS 4 (CZTS) thin films, different selenization atmosphere (Vacuum or Ar) are used. By examining the annealed sample, it is found that selenization under Ar atmosphere replaces S with Se more efficiently, resulting large grain and small band-gap. The reaction kinetics has been studied to explore such phenomena. It demonstrates that the substitution reaction is enhanced when the flowing Ar carries off S gas. Finally, the effect of annealing atmosphere on oxide-based CZTSSe devices has also been studied. The Vacuum selenized CZTSSe device shows a higher efficiency of 4.4%, due to the more appropriate band-gap. To the best of our knowledge, this is the best device performance in oxides nanoparticles-derived CZTSSe solar cell. [ABSTRACT FROM AUTHOR]

Exploring new optical thermometric materials is important to realize highly accurate temperature detecting. Herein, Yb/Er activators are successfully doped into Cs 2 Ag(In/Bi)Cl 6 lead-free double perovskite (DP) semiconductor, providing dual-modal photoluminescence originated from self-trapped exciton recombination and 4f-4f transitions of Yb/Er dopants as well as Er3+ upconversion emissions. Remarkably different temperature-dependent emissive behaviors from DP host and Yb/Er activators are experimentally demonstrated, which enables to design novel fluorescence intensity ratio (FIR) between DP and Yb/Er based thermometric technology. In addition, upconversion FIR-based temperature sensing via thermal population between the 2H 11/2 level and 4S 3/2 one of Er3+ dopants in DP host is also realized. It is believed that the present Yb/Er: Cs 2 Ag(In/Bi)Cl 6 DP with excellent long-term stability and dual-functional temperature detecting is a suitable candidate as the self-calibrated optical thermometric material. The combination of the exciton recombination of Cs 2 AgInCl 6 lead-free double perovskite with Ln3+ (Ln = Yb, Er) dopants induces dual-modal light-emitting channel to produce a novel thermometric material. [Display omitted] • Yb/Er: Cs 2 Ag(In/Bi)Cl 6 lead-free double perovskite is successfully prepared. • The product exhibits both self-trapped exciton recombination and Ln3+: 4f-4f emissions. • Different temperature-dependent emissive behaviors from host and Ln3+ activators are demonstrated. • A novel DP/Ln3+ fluorescence intensity ratio thermometric channel is developed. • The product is a promising candidate for dual-modal optical temperature sensing. [ABSTRACT FROM AUTHOR]

Abstract: Rare earth (RE)—3d transition metal (TM) films were codeposited in low temperature urea–acetamide–NaBr–KBr–RECl3–TMCl2 baths by potentiostatic electrolysis. Cyclic voltammetry is used to investigate the electrochemical behavior of RE(III) and TM(II) in baths on a Pt electrode. The reduction of TM(II) is an irreversible process. RE(III) cannot be reduced alone, but it can be inductively codeposited with TM(II). Some kinetic parameters are measured, e.g., the transfer coefficient α and the diffusion coefficient D 0 for TM(II). It is reasonably suggested that the RE-induced codeposition ability and efficiency is dominated by the electronegativity difference between RE and TM atoms. Moreover, it is found that the surface morphologies, the magnetic anisotropy and preferring orientation of the as-deposited RE–TM films depend strongly on the composition and potential. At last, it is observed that, there exists a clear anisotropy with easy magnetization along the plane of the RE–TM films. The magnetic anisotropy in amorphous RE–TM films should be due to the competing contributions from several factors, such as spin–orbit coupling, stress, etc. [Copyright &y& Elsevier]

The inhomogeneity distribution of applied magnetic field along longitudinal direction above permanent magnetic guideway (PMG) reduces the levitation stability of the high- T c superconductor (HTS) maglev system. In order to explore and reveal the inhomogeneity distribution of magnetic field along longitudinal direction above PMG and its causes, as well as its influence on the static levitation force of YBa 2 Cu 3 O 7- x (YBCO) bulk, the theoretical model is built by COMSOL Multiphysics to simulate the longitudinal distribution of magnetic field above the PMG and the static levitation force of the YBCO bulk. Furthermore, a three-axis motion experimental platform is designed and built to measure the longitudinal distribution of magnetic field, upper surface profile of the PMG and static levitation force of the YBCO bulk by the corresponding testing equipment. It is shown in this study that, in the assembly processing of PMG, the surface of permanent magnet (PM) is sloping along the longitudinal direction, and there are gaps and damage between adjacent PMs. The simulation and experimental results show that these multiple defects lead to inhomogeneity distribution of magnetic field along the longitudinal direction and the attenuation at the joints, resulting in the difference in the static levitation force of YBCO bulk at different longitudinal positions of the PMG. The results could provide a reference for the further design and practical application of higher performance PMG. [ABSTRACT FROM AUTHOR]