Photoluminescence (PL) properties of ZnO thin films are increasingly important in the applications of display and lighting, therefore enhancing it by doping different elements becomes the focus of ...researches. To significantly improve the PL ability, lithium-doped ZnO (LZO) thin films were synthesized via sol-gel method in this study. Different from the previous studies on lithium (Li) doping which emphasized electrical properties, the keystone of our study was put on the optics properties overlooked before, and we systematically investigated the photoluminescence mechanism. This study illustrated that defect concentrations of thin films were enhanced significantly after introducing Li, and doping mode mainly showed interstitial site at high doping concentration (such as 16 at.%). In this meantime, photoluminescence of all thin films showed 12 components including a near-band-edge emission at 393 nm and the eleven defect emissions at 407–581 nm, in which Li-related defects may induce a green emission and a yellow emission at 526 nm and at 574 nm respectively. Delightedly and surprisingly, the 16 at.% LZO thin films handed a huge victory in improvement of overall luminous intensity, which was at least six-fold increase compared with un-doped ZnO. This work may reveal further potential for high performance luminescent devices based on ZnO.
Chiral metasurfaces can achieve giant chiral optical responses and have been expanded from the optical band to other electromagnetic bands. Here, we propose a new method for dynamic terahertz ...circular dichroism (CD) manipulation in metasurfaces. By introducing a patterned and electrically doped graphene into the metamirror consists of double layer C-shaped split ring resonators (SRRs), efficient terahertz CD modulation is observed. Since the electrical doping of graphene changes the absorption loss of the metasuface cavity, the structure shows switching between a chiral metasurface and an ordinary metal mirror, which can be seen as "on" and "off" states. The calculation results show an efficient modulation of the terahertz CD in a large dynamic range. In addition, we also use the new method to design two metasurfaces for dynamic terahertz wavefront modulation and near-field digital imaging, both of which show a high-performance electrical switching. This method provides a new way for the design of active terahertz devices based on metasurfaces, and also promotes the applications of terahertz chiral metasurfaces in high-speed wireless communication and dynamic imaging.
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The ZnO thin films have been prepared by sol-gel method at different annealing temperatures and aging time. The structural properties of ZnO thin films were investigated by X-ray diffraction (XRD) ...patterns and atomic force microscope (AFM) images. The results indicated that the film possess a hexagonal wurtzite structure with preferred orientation along the (002) direction. The crystalline quality of films improved with increasing post-annealing temperature, while gradually worsened with prolonging aging time. The optical properties of ZnO thin films were studied by the ultra-violet transmittance (UV-Vis) and photoluminescence (PL) spectra. The variations of UV-Vis transmittance and energy gap accorded well with the tendency presented in XRD patterns and AFM images. The PL spectra appeared the apparent ultraviolet emission and visible emissions. As the annealing temperature increased, the ultraviolet and visible emissions of films enhanced and decreased respectively. However, as the sol aging time prolonged, the PL emission presented an opposite tendency.
High alkalinity stress was considered as a major risk factor for aquatic animals surviving in saline-alkaline water. However, few information exists on the effects of alkalinity stress in crustacean ...species. As the dominant role of gills in osmotic and ionic regulation, the present study firstly evaluated the effect of alkalinity stress in Exopalaemon carinicauda to determine changes in gill microstructure, and then explore the heterogeneity response of gill cells in alkalinity adaptation by single-cell RNA sequencing (scRNA-seq). Hemolymph osmolality and pH were increased remarkably, and gills showed pillar cells with more symmetrical arrangement and longer lateral flanges and nephrocytes with larger vacuoles in high alkalinity. ScRNA-seq results showed that alkalinity stress reduced the proportion of pillar cells and increased the proportion of nephrocytes significantly. The differentially expressed genes (DEGs) related to ion transport, especially acid-base regulation, such as V(H+)-ATPases and carbonic anhydrases, were down-regulated in pillar cells and up-regulated in nephrocytes. Furthermore, pseudotime analysis showed that some nephrocytes transformed to perform ion transport function in alkalinity adaption. Notedly, the positive signals of carbonic anhydrase were obviously observed in the nephrocytes after alkalinity stress. These results indicated that the alkalinity stress inhibited the ion transport function of pillar cells, but induced the active role of nephrocytes in alkalinity adaptation. Collectively, our results provided the new insight into the cellular and molecular mechanism behind the adverse effects of saline-alkaline water and the saline-alkaline adaption mechanism in crustaceans.
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•Alkalinity stress caused homeostasis disturbance in Exopalaemon carinicauda.•Alkalinity stress resulted in gills histopathological alternations.•Alkalinity stress inhibited the ion transport function of pillar cells in gills.•Nephrocytes in gills played an active role in alkalinity adaptation.
The disordered expression of ZNF143 is closely related to the malignant progression of tumours. However, the basic control mechanism of ZNF143 in glioma has not yet been clarified. Therefore, we ...tried to find a new pathway to illustrate the function of ZNF143 in glioma. To explore the function of KPNA2 in the development of glioma, we used survival analysis by the Kaplan‒Meier method to assess the overall survival (OS) of patients with low and high KPNA2 expression in the TCGA and CGGA cohorts. Western blotting assays and RT‒PCR assays were utilized to determine the expression level of KPNA2 in glioma cells. The interaction between ZNF143 and KPNA2 was confirmed by ChIP assays. Proliferation was assessed by CCK-8 assays, and migration was evaluated by wound healing and Transwell assays. Apoptosis was determined by flow cytometry, and the expression level of YAP/TAZ was visualized using an immunofluorescence assay. The expression levels of LATS1, LATS2, YAP1, and p-YAP1 were determined. Patients with low KPNA2 expression showed a better prognosis than those with high KPNA2 expression. KPNA2 was found to be upregulated in human glioma cells. ZNF143 can bind to the promoter region of KPNA2. Downregulation of ZNF143 and KPNA2 can activate the Hippo signalling pathway and reduce YAP/TAZ expression in human glioma cells, thus inducing apoptosis of human glioma cells and weakening their proliferation, migration and invasion. In conclusion, ZNF143 mediates the Hippo/YAP signalling pathway and inhibits the growth and migration of glioma cells by regulating KPNA2.
This article discusses the interval estimation for 2-D systems in Roesser model with amplitude-bounded environmental disturbance and measurement noise. To save the limited capacity of communication ...network, an event-triggered communication strategy is adopted to reduce the amount of packets transmitted through the network. Considering the amplitude-bounded uncertainties, an observer design criterion with peak-to-peak norm bound is deduced to suppress the influence of uncertainties on estimation error. A zonotope-based interval estimation approach is derived such that the actual state of 2-D Roesser system is enclosed within the estimated intervals on the basis of the obtained observer. Finally, a numerical example is presented to verify the effectiveness of the proposed algorithm.
A reduction correlation between the
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In this paper, the effect of sputtering distance between target and substrate (DTS) on the structural, morphological and optical properties of TiO2 films were investigated. X-ray diffraction (XRD) ...and scanning electron microscopy (SEM) revealed that crystallite size and surface morphology were strongly dependent on DTS. The X-ray photoelectron spectroscopy (XPS) results showed that obvious three peaks including C1S, Ti2p and O1s could be clearly observed and the binding energy was 285, 458 and 531 eV, respectively. For each sample, four peaks near 386, 462, 527 and 595 nm in photoluminescence (PL) spectra were observed and originated from intrinsic recombination, F center, F+ center and electrons transferred from 3d Ti3+ states to the deep levels OH−, respectively. Finally, the photoresponse properties of UV detectors based on TiO2 films were analyzed and the TiO2 UV detector prepared at a DTS of 80 mm showed high responsivity of 2.02 × 10−4 A/W and excellent photosensitivity of 32.25, also, exhibited a fast response with a rise time (τr) of 0.98 s and fall time (τf) of 3.14 s.
•TiO2 films was successfully prepared by magnetron sputtering technology.•Properties of TiO2 films UV detector were mainly decided by oxygen vacancy.•Device showed a fast response with rise time of 0.98 s and fall time of 3.14 s.•Device showed a high photosensitivity of 32.25.
Optical metasurfaces have advanced approaches for manipulating light information in the spatial domain, in which the spatially interleaved metasurfaces demonstrate the ability to manipulate a more ...complex wavefront of light than metasurfaces without the spatial interleaving. The potential of the spatially interleaved metasurfaces has not been fully exploited. In this paper, we design the spatially interleaved terahertz (THz) metasurfaces based on the ingenious spatial interleaving principles to develop the diverse THz wavefront manipulations. Four functions are performed, including the orbital angular momentum (OAM) superposition of single-frequency vortex beams, the separate vortex focusing of single-frequency dual beams, the different OAM manipulations of bifrequency beams in different planes, and achromatic focusing. The demonstrated functions prove that the spatially interleaved metasurface can manipulate THz wavefront at both single frequency and bifrequency, which traditional metasurfaces cannot. This work paves the way for diverse THz wavefront manipulations.
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