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TiO2 photocatalysts doped with Be2+ were prepared by impregnation and coprecipitation method. The samples were characterized by XRD, XPS and IR. Their activities were evaluated by photocatalytic hydrogen production. It is found that Be2+ can enter into the interstitial site of TiO2 lattice, and the photocatalytic activities depend on doping method. When the doping ions were in the shallow surface, the doping was beneficial; while in the deep bulk, the doping was detrimental. On the optimum conditions, the photocatalytic activity of the doped TiO2 increased by 75% compared to pure TiO2. [Copyright &y& Elsevier]

Abstract: A nitrogen-doped TiO2 (N-TiO2) photocatalyst was prepared by calcination of the hydrolysis precipitate of Ti(SO4)2 with aqueous ammonia. The prepared N-TiO2 was treated with NH4F (F-N-TiO2) by an impregnation-calcination method. The photocatalyst (F-N-TiO2) was characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), UV–vis diffusive reflectance spectroscopy (DRS), BET and X-ray photoelectron spectroscopy (XPS). With blue light-emitting diode (LED) as the light source, its photocatalytic activity for the degradation of formaldehyde was investigated. NH4F treatment enhances markedly photocatalytic activity of N-TiO2. The treatment increases the visible absorption of N-TiO2, decreases its specific surface area and influences the concentration of oxygen vacancies in N-TiO2. Photocatalytic activity of F-N-TiO2 depends on the visible absorption, the specific surface area, and the concentration of oxygen vacancies. The preparation conditions, such as the calcination temperature and the initial molar ratio of NH4F to N-TiO2, have a significant influence on the photocatalytic activity. The doping mechanism of NH4F was investigated. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we compare the properties of ZnO thin films (0001) sapphire substrate using diethylzinc (DEZn) as the Zn precursor and deionized water (H2O) and nitrous oxide (N2O) as the O precursors, respectively in the main ZnO layer growth by atmospheric pressure metal–organic chemical vapor deposition (AP-MOCVD) technique. Surface morphology studied by atomic force microscopy (AFM) showed that the N2O-grown ZnO film had a hexagonal columnar structure with about 8μm grain diameter and the relatively rougher surface compared to that of H2O-grown ZnO film. The full-widths at half-maximum (FWHMs) of the (0002) and () ω-rocking curves of the N2O-grown ZnO film by double-crystal X-ray diffractometry (DCXRD) measurement were 260 and 350arcsec, respectively, indicating the smaller mosaicity and lower dislocation density of the film compared to H2O-grown ZnO film. Compared to H2O-grown ZnO film, the free exciton A (FXA) and its three phonon replicas could be clearly observed, the donor-bound exciton A0X (I 10):3.353eV dominated the 10K photoluminescence (PL) spectrum of N2O-grown ZnO film and the hydrogen-related donor-bound exciton D0X (I 4):3.363eV was disappeared. The electron mobility (80cm2/Vs) of N2O-grown ZnO film has been significantly improved by room temperature Hall measurement compared to that of H2O-grown ZnO film. [Copyright &y& Elsevier]

Abstract: In this paper, we present the epitaxial growth of high-quality ZnO thin films on GaN/c-Al2O3 templates by atmospheric pressure metal organic chemical vapor deposition (MOCVD) using deionized water (H2O) and diethyl zinc (DEZn) as the O and Zn sources, respectively. Surface morphology of the films studied by metal-phase interference microscopy and AFM showed that the growth of the ZnO films followed the regular hexagonal columnar structure with about 19μm grain diameter. High-resolution X-ray double-crystal diffraction was used to investigate the structural properties of the as-grown films. The FWHMs of the (0002) and () ω-rocking curves were 182 and 358arcsec, respectively, indicating the small mosaicity and low dislocation density of the films. The optical properties of the films were investigated by room temperature photoluminescence and temperature-dependent PL spectra. Free excitons XA and the state of FXA can be clearly observed at 3.375 and 3.419eV at 10K, respectively. The domination of the free exciton and the appearance of its four replicas strongly indicate the high quality of the film. [Copyright &y& Elsevier]

Abstract: ZnO thin films on (0001) sapphire large area substrates (Φ50×0.43mm) have been deposited by atmospheric pressure MOCVD. To investigate the effects of post-annealing treatment on the structural and luminescent properties of ZnO thin films, films have been annealed in nitrogen at various annealing temperatures from 400 to 800°C. The best crystal quality of ZnO films was obtained with annealing temperatures up to 800°C by measuring the FWHM of (102) and (002) peak. At annealing temperature above 700°C, the intensity of UV (377nm) peak is greatly decreased, and the deep-level emission peak (500 or 500–525nm) is enhanced. The study of structural and luminescent properties of ZnO thin films annealed in nitrogen shows that the crystallinity of ZnO thin films is not easily degraded by oxygen vacancies, or say, the deficient oxygen nonstoichiometric ZnO single crystal films may be of better crystallinity as that of the deficient nitrogen nonstoichiometric single crystal GaN films reported. [Copyright &y& Elsevier]

The effects of the preparation layer grown under different conditions, which is an InGaN/GaN SLs structure inserted between the n-GaN layer and the MQWs, on the performance of green-yellow LED have been investigated. In this paper, the quality of InGaN/GaN multiple quantum wells (MQWs) and the optoelectronic properties of LED have been focused on. According to the experimental results, when the growth temperature of GaN barriers in SLs was increased, the interface between InGaN layers and GaN layers became more abrupt, and the indium distribution in the quantum wells became more uniform. In consequence, the forward voltage was reduced, the external quantum efficiency (EQE) was improved. By decreasing the growth rate of the high temperature barriers, the indium uniformity became even better, forward voltage was reduced again and EQE was further improved. • The growth conditions of the InGaN/GaN preparation layer is optimized to enhance the efficiency of the green-yellow LED. • The two-step varied-barrier-growth temperature method is adopted to grow InGaN/GaN superlattice preparation layer. • A high interface quality of MQWs results in a uniform distribution of Indium. [ABSTRACT FROM AUTHOR]

Affordable clean energy is one of the major sustainable development goals that can transform our world. At present, researchers are working to develop cheap electrode materials to develop energy storage devices, the Lithium-sulfur (Li-S) battery is considered a promising energy storage device owing to its excellent theoretical specific capacity and energy density. Herein, utilizing the ramie degumming waste liquid as raw materials, after freeze-drying and high-temperature calcination, a sustainable and cost-effective three-dimensional (3D) porous nitrogen-doped ramie carbon (N-RC) was synthesized. The N-RC calcined at 800 °C (N-RC-800) shows a superior high specific surface area of 1491.85 m 2  ⋅ g -1 and a notable high pore volume of 0.90 cm 3  ⋅ g -1 . When employed as a sulfur host, the S@N-RC-800 cathode illustrates excellent initial discharge capacity (1120.6 mAh ⋅ g -1 ) and maintains a reversible capacity of 625.4 mAh ⋅ g -1 after 500 cycles at 1 C. Simultaneously, the S@N-RC-800 cathode also shows excellent coulombic efficiency and ideal rate performance. Such exceptional electrochemical performance of S@N-RC-800 can be primarily attributable to N-RC's high specific surface area, high porosity, and abundant polar functional groups. This green and low-cost synthesis strategy offers a new avenue for harnessing the potential of waste biomass in the context of clean energy storage., (© 2024 Wiley-VCH GmbH.)

Background: Acanthopanax senticosus (AS) can improve sleep, enhance memory, and reduce fatigue and is considered as an effective drug for Alzheimer's disease (AD). The therapeutic effect and mechanism need to be further investigated., Methods: To confirm the AS play efficacy in alleviating memory impairment in mice, 5×FAD transgenic mice were subjected to an open-field experiment and a novelty recognition experiment. Network pharmacology technique was used to analyze the information of key compounds and potential key targets of AS for the treatment of AD, molecular docking technique was applied to predict the binding ability of targets and compounds, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were also performed on the targets to derive the possible metabolic processes and pathway mechanisms of AS in treating AD. Quantitative real-time PCR (qRT-PCR) and western blot technique were carried out to validate the candidate genes and pathways., Results: In the open-field experiment, compared with the wild-type (WT) group, the number of times the mice in the AD group crossed the central zone was significantly reduced ( P < 0.01). Compared with the AD group, the number of times the mice in the AS group crossed the central zone was significantly increased ( P < 0.001). In the new object recognition experiment, compared with the WT group, the percentage of times the AD group explored new objects was significantly reduced ( P < 0.05). Compared with the AD group, the AS group had an increase in the percentage of time spent exploring new things and the number of times it was explored ( P < 0.05). At the same time, the donepezil group had a significantly higher percentage of times exploring new things ( P < 0.01). By using network pharmacology technology, 395 common targets of AS and AD were retrieved. The Cytoscape software was used to construct the protein-protein interaction (PPI) network of common targets. Using the algorithm, nine key targets were retrieved: APP, NTRK1, ESR1, CFTR, CSNK2A1, EGFR, ESR2, GSK3B, and PAK1. The results of molecular docking indicate that 11 pairs of compounds and their corresponding targets have a significant binding ability, as the molecular binding energies were less than -7.0. In comparison to the AD group, the mRNA expression of the key target genes was significantly decreased in the AS treatment group ( P < 0.001). The KEGG analysis showed that the MAPK signaling pathway was significantly enriched, and Western blot confirmed that the TRAF6 protein decreased significantly ( P < 0.0001). Meanwhile, the levels of MAP3K7 and P38 phosphorylation increased, and there was also an increase in the expression of HSP27 proteins., Conclusion: Our study indicates that the multi-component and multi-target properties of AS play an important role in the alleviation of anxiety and memory impairment caused by AD, and the mechanism is involved in the phosphorylation and activation of the MAPK signaling pathway. The results of this study could provide a novel perspective for the clinical treatment of AD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhang, Wu, Shi, Jiang, Cao, Jiang, Bao, Shen and Shi.)

In this work, we discuss the precision of the effective medium approximation (EMA) model in the data analysis of spectroscopic ellipsometry (SE) for solid materials with micro-rough surfaces by drawing the regime map. The SE parameters ψ (amplitude ratio) and Δ (phase difference) of the EMA model were solved by rigorous coupled-wave analysis. The electromagnetic response of the actual surfaces with micro roughness was simulated by the finite-difference time-domain method, which was validated by the experimental results. The regime maps associated with the SE parameters and optical constants n (refractive index) and k (extinction coefficient) of the EMA model were drawn by a comparison of the actual values with the model values. We find that using EMA to model micro-rough surfaces with high absorption can result in a higher precision of the amplitude ratio and extinction coefficient. The precisions of ψ, Δ, n and k increase as the relative roughness σ/λ (σ: the root mean square roughness, λ: the incident wavelength) decreases. The precision of ψ has an influence on the precision of k and the precision of Δ affects the precision of n. Changing σ alone has little effect on the regime maps of the relative errors of SE parameters and optical constants. A superior advantage of drawing the regime map is that it enables the clear determination as to whether EMA is able to model the rough surfaces or not.

Alzheimer's disease (AD) is a prevalent neurodegenerative disease account for 60-80% of the total number of people with dementia, but its treatment and prevention strategies are still in a long process of exploration. It has been reported that a healthy lifestyle may be an effective non-pharmacological intervention for the prevention and treatment of AD, including increased physical activity and the consumption of polyphenol-rich foods. This study, therefore, investigated the effects of 8 weeks of moderate-intensity aerobic exercise (EX), administration of chlorogenic acid administration (GCA), and a combination of both (EX+GCA) on β-amyloid (Aβ) deposition, inflammatory factors, oxidative stress markers, neuronal damage, and cognitive performance in the brains of AD model mice (APP/PS1) and which signaling pathways may be responsible for these effects. The study used Western blot to detect the expression of signaling pathway-related proteins, enzyme-linked immunosorbent assay to detect the expression of inflammatory factors, hematoxylin-eosin staining to detect hippocampal neuronal morphology, immunohistochemistry to detect changes in Aβ deposition in the hippocampus, an oxidative stress marker kit to detect oxidative stress status and the Morris water maze to detect changes in cognitive performance. This study showed that an 8-week intervention (EX/GCA/EX+GCA) activating the SIRT1/PGC-1α signaling pathway improved oxidative stress, neuroinflammation, Aβ deposition, and cognitive performance in mice. However, there was no obvious difference between the EX and GCA groups. In contrast, the combined EX+GCA intervention was significantly better than phase EX or GCA. Our study suggests that although relief of Aβ deposition, neuroinflammation, oxidative stress, neuronal damage, and cognitive decline could also be achieved with EX or GCA, the combined EX+GCA intervention showed better results. These relief effects on AD-related conditions may be obtained by mediating the activation of the SIRT1/PGC-1α signaling pathway. This study is the first to explore the improvement of AD-related conditions with a combined lifestyle of EX+GCA. This healthy lifestyle could be a candidate option for the treatment of AD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Shi, Hao, Qi, Jiang, Liu and Shi.)

Salient object detection (SOD), which is used to identify the most distinctive object in a given scene, plays an important role in computer vision tasks. Most existing RGB-D SOD methods employ a CNN-based network as the backbone to extract features from RGB and depth images; however, the inherent locality of a CNN-based network limits the performance of CNN-based methods. To tackle this issue, we propose a novel Swin Transformer-based edge guidance network (SwinEGNet) for RGB-D SOD in which the Swin Transformer is employed as a powerful feature extractor to capture the global context. An edge-guided cross-modal interaction module is proposed to effectively enhance and fuse features. In particular, we employed the Swin Transformer as the backbone to extract features from RGB images and depth maps. Then, we introduced the edge extraction module (EEM) to extract edge features and the depth enhancement module (DEM) to enhance depth features. Additionally, a cross-modal interaction module (CIM) was used to integrate cross-modal features from global and local contexts. Finally, we employed a cascaded decoder to refine the prediction map in a coarse-to-fine manner. Extensive experiments demonstrated that our SwinEGNet achieved the best performance on the LFSD, NLPR, DES, and NJU2K datasets and achieved comparable performance on the STEREO dataset compared to 14 state-of-the-art methods. Our model achieved better performance compared to SwinNet, with 88.4% parameters and 77.2% FLOPs. Our code will be publicly available.

In this paper, we studied a series of high-speed photodetectors (PD) with different super-lattice interlayer periods and the scale of the effective area to examine their communication performance. The mini-PDs are designed with a single 1 mm × 1 mm effective area. The mini-PDs have three different super-lattice (SL) periods in the interlayer: 8, 15, and 32. The micro-PD sample has multiple 50um by 50um photosensitive areas that form a 4 × 4 receiver array, which shares a common N electrode. Its SL period is 26. The experiment shows that mini-PDs have the advantages such as better tolerance to beam spot deviation, larger field of view (FoV), higher responsibility, and wider peak width in spectral response. But micro-LED samples outperform the others in communication capacity and wavelength selectivity. The 8, 15, and 32 SL mini-PD samples achieve 6.6, 7.3, and 8.8 Gb/s data rates, respectively. The micro-PD gains the maximum data rate of 14.38Gb/s without applying waveform level post-equalization, and 15.26Gb/s after using an NN-based post-equalizer. This experiment shows that with proper DSP, GaN-based PD would be suitable for high-speed VLC systems, especially for the short wavelength spectrum in visible light.

RGB-D saliency detection aims to accurately localize salient regions using the complementary information of a depth map. Global contexts carried by the deep layer are key to salient objection detection, but they are diluted when transferred to shallower layers. Besides, depth maps may contain misleading information due to the depth sensors. To tackle these issues, in this paper, we propose a new cross-modal cross-scale network for RGB-D salient object detection, where the global context information provides global guidance to boost performance in complex scenarios. First, we introduce a global guided cross-modal and cross-scale module named G 2 CMCSM to realize global guided cross-modal cross-scale fusion. Then, we employ feature refinement modules for progressive refinement in a coarse-to-fine manner. In addition, we adopt a hybrid loss function to supervise the training of G 2 CMCSNet over different scales. With all these modules working together, G 2 CMCSNet effectively enhances both salient object details and salient object localization. Extensive experiments on challenging benchmark datasets demonstrate that our G 2 CMCSNet outperforms existing state-of-the-art methods.

The presence of manufacture error in large mirrors introduces high-order aberrations, which can severely influence the intensity distribution of point spread function. Therefore, high-resolution phase diversity wavefront sensing is usually needed. However, high-resolution phase diversity wavefront sensing is restricted with the problem of low efficiency and stagnation. This paper proposes a fast high-resolution phase diversity method with limited memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm, which can accurately detect aberrations in the presence of high-order aberrations. An analytical gradient of the objective function for phase-diversity is integrated into the framework of the L-BFGS nonlinear optimization algorithm. L-BFGS algorithm is specifically suitable for high-resolution wavefront sensing where a large phase matrix is optimized. The performance of phase diversity with L-BFGS is compared to other iterative method through simulations and a real experiment. This work contributes to fast high-resolution image-based wavefront sensing with a high robustness.

Ellipticity performance of space telescopes is important for exploration of dark matter. However, traditional on-orbit active optical alignment of space telescopes often takes "minimum wavefront error across the field of view" as the correction goal, and the ellipticity performance after correcting the wave aberration is not optimal. This paper proposes an active optical alignment strategy to achieve optimal ellipticity performance. Based on the framework of nodal aberration theory (NAT), the aberration field distribution corresponding to the optimal full field-of-view ellipticity is determined using global optimization. The degrees of freedom (DOFs) of the secondary mirror and the folded flat mirror are taken as the compensation DOFs to achieve the optimal ellipticity performance. Some valuable insights into aberration field characteristics corresponding to optimal ellipticity performance are presented. This work lays a basis for the correction of ellipticity for complicated optical systems.

A segmented primary mirror (PM) is an efficient solution to the problems of a monolithic PM manufacture, testing, transportation, and launch. However, the problem of the radius of curvature (ROC) matching among PM segments will arise, which if not solved will seriously degrade the final imaging quality of the system. Accurately detecting ROC mismatch among PM segments from the wavefront map is of crucial importance for efficiently correcting this kind of manufacturing error, while currently there are few related studies. Based on the inherent relation between the PM segment's ROC error and corresponding sub-aperture defocus aberration, this paper proposes that the ROC mismatch can be accurately estimated from the sub-aperture defocus aberration. Secondary mirror (SM) lateral misalignments will influence the accuracy of estimating ROC mismatch. A strategy is also proposed to reduce the influence of SM lateral misalignments. Detailed simulations are performed to demonstrate the effectiveness of the proposed method for detecting ROC mismatch among PM segments. This paper paves a road for detecting ROC mismatch using image-based wavefront sensing methods.

GaN green LED was grown on Si (111) substrate by MOCVD. To enhance the quality of InGaN/GaN MQWs, same-temperature (ST) GaN protection layers with different thickness of 8 Å, 15 Å, and 30 Å were induced after the InGaN quantum wells (QWs) layer. Results show that a relative thicker cap layer is benefit to get InGaN QWs with higher In percent at fixed well temperature and obtain better QW/QB interface. As the cap thickness increases, the indium distribution becomes homogeneous as verified by fluorescence microscope (FLM). The interface of MQWs turns to be abrupt from XRD analysis. The intensity of photoluminescence (PL) spectrum is increased and the FWHM becomes narrow.