Jiangxi University of Science and Technology

About: Jiangxi University of Science and Technology is a education organization based out in Ganzhou, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 6958 authors who have published 5576 publications receiving 50650 citations.

An ultra-high yield of spherical K2NaScF6:Mn4+ red phosphor and its application in ultra-wide color gamut liquid crystal displays

Abstract: Mn4+-Activated narrow-band red-emitting fluoride phosphors are an efficient red compensator able to widen the color gamut and improve the color quality of pc-WLEDs for backlight display applications. However, the low synthetic yields and extremely non-uniform, irregular morphologies of these fluorides seriously restrict their practical industrial applications. Herein, a novel Mn4+-doped narrow-band red-emitting phosphor K2NaScF6:Mn4+ was prepared through a simple co-precipitation route. High-resolution synchrotron XRD and its Rietveld refinement reveal that K2NaScF6:Mn4+ crystallized in the space group Fmm with a cubic structure and that the octahedral Sc3+ sites were occupied by Mn4+, resulting in a very small amount of alkali metal cation vacancies for charge compensation. The electronic band gap of K2NaScF6 was calculated to be 6.46 eV by DFT calculations, which ensured the location of Mn4+ energy levels in the host band gap and was verified by DRS results. Unlike previously reported Mn4+-activated fluorides, K2NaScF6:Mn4+ has an ultra-high synthetic yield (∼100%) and a uniform spherical morphology with extremely narrow size distribution (∼1.17 μm). Excess KHF2 and the extremely low solubility of K2NaScF6 were shown to be responsible for the high synthetic yield of K2NaScF6:Mn4+. Under blue light illumination, K2NaScF6:Mn4+ exhibited an intense sharp-line red fluorescence peak at 630 nm. Meanwhile, the ZPL intensity could be tailored through the control of Mn4+ amount in the K2NaScF6 matrix. By employing the efficient and stable K2NaScF6:Mn4+ as an efficient red emitter, two pc-WLEDs with ultra-wide color gamut (Rec. 2020 value of 95.1% and NTSC value of 127.3% for LED-1, Rec. 2020 value of 96.7% and NTSC value of 129.5% for LED-2) were successfully obtained. These results suggest the great potential of K2NaScF6:Mn4+ as a red-emitting phosphor for applications in high-quality backlight displays, and this work may open a perspective for researchers to design new luminescence materials with high synthetic yield and uniform spherical morphology.

Classical-driving-enhanced parameter-estimation precision of a non-Markovian dissipative two-state system

Abstract: The dynamics of quantum Fisher information (QFI) of the phase parameter in a driven two-state system is studied within the framework of the non-Markovian dissipative process. The influences of memory effects, classical driving, and detunings on the parameter-estimation precision are demonstrated by exactly solving the Hamiltonian under rotating-wave approximation. In sharp contrast with the results obtained in the presence of Markovian dissipation, we find that classical driving can drastically enhance the QFI, namely, the precision of parameter estimation in the non-Markovian regime. Moreover, the parameter-estimation precision may even be preserved from the influence of surrounding non-Markovian dissipation with the assistance of classical driving. Remarkably, we reveal that the enhancement and preservation of QFI highly depend on the combination of classical driving and non-Markovian effects. Finally, a phenomenological explanation of the underlying mechanism is presented in detail via the quasimode theory.

An Ontology-Based Resource Reconfiguration Method for Manufacturing Cyber-Physical Systems

Abstract: The introduction of Industry 4.0 and rapid development of manufacturing cyber-physical systems, as well as the increasing demand for multivariety, small batch, and personalized customization, pose a huge challenge to traditional manufacturing systems. In order to meet production requirements for fast iteration and realize agile and efficient manufacturing resource allocation, this paper proposes an ontology-based resource reconfiguration method from the perspective of resource utilization. First, an intelligent device ontology that describes the intelligent manufacturing resource is established using the Web Ontology Language. On this basis, the relational database is associated with the ontology of the manufacturing system, which makes the manufacturing resources be mapped to the model instances. Then, we analyze the equipment reconfiguration of the intelligent manipulator as an application case, which explains the proposed method for resource reconfiguration based on ontology, and verifies its feasibility in manufacturing. Finally, this study provides a new method for reconfigurable research of manufacturing resources.