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Dendrobium, a highly effective traditional Chinese medicinal herb, exhibits significant variations in efficacy and price among different varieties. Therefore, achieving an efficient classification of Dendrobium is crucial. However, most of the existing identification methods for Dendrobium make it difficult to simultaneously achieve both non-destructiveness and high efficiency, making it challenging to truly meet the needs of industrial production. In this study, we combined Laser-Induced Breakdown Spectroscopy (LIBS) with multivariate models to classify 10 varieties of Dendrobium. LIBS spectral data for each Dendrobium variety were collected from three circular medicinal blocks. During the data analysis phase, multivariate models to classify different Dendrobium varieties first preprocess the LIBS spectral data using Gaussian filtering and stacked correlation coefficient feature selection. Subsequently, the constructed fusion model is utilized for classification. The results demonstrate that the classification accuracy of 10 Dendrobium varieties reached 100%. Compared to Support Vector Machine (SVM), Random Forest (RF), and K-Nearest Neighbors (KNN), our method improved classification accuracy by 14%, 20%, and 20%, respectively. Additionally, it outperforms three models (SVM, RF, and KNN) with added Principal Component Analysis (PCA) by 10%, 10%, and 17%. This fully validates the excellent performance of our classification method. Finally, visualization analysis of the entire research process based on t-distributed Stochastic Neighbor Embedding (t-SNE) technology further enhances the interpretability of the model. This study, by combining LIBS and machine learning technologies, achieves efficient classification of Dendrobium, providing a feasible solution for the identification of Dendrobium and even traditional Chinese medicinal herbs. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) has been widely studied as a photocatalyst owing to its advantages of low cost, good stability, and nonpollution. However, they can only be excited by ultraviolet light, resulting in low utilization of solar energy and limited photocatalytic efficiency. In recent years, researchers have found that the nonprecious metal Al can effectively improve the photocatalytic performance of TiO2. However, the current studies focus only on enhancing the ultraviolet photocatalysis performance of semiconductors with Al on the substrate. In this study, Al nanoparticles (NPs) and TiO2 were prepared into composite materials. The effects of ligand, Al particle size, and the molar ratio of Al and TiO2 on the photocatalytic degradation of methylene blue (MB) by Al NPs and TiO2 composites (Al NPs/TiO2) were investigated. The results showed that the Al NPs/TiO2 prepared with a particle size of 200 nm of Al, glutathione as the ligand bridge, and an Al:TiO2 ratio of 2:1 were the most effective for the degradation of MB. The degradation rate of 5 mg/L MB solution within 70 min under visible light was up to 99.5%, which was three times higher than that of P25 TiO2. The photocatalytic performance was further enhanced under sunlight with a degradation rate of 99.7% within 50 min, which is four times higher than that of P25 TiO2 under the same light source. Therefore, Al NPs/TiO2 is a potential photocatalytic material for the treatment of organic pollutants in water. [ABSTRACT FROM AUTHOR]

The issue of water pollution has emerged as a formidable challenge, prompting a pressing need for solutions. The utilization of metal nanoparticles with surface plasmon resonance and semiconductor composite photocatalysts is regarded as a highly effective approach to solve this problem. g-C3N4 is an effective catalyst for the degradation of organic pollutants. Its photocatalytic performance is usually enhanced by the use of the noble metal Au Ag. However, the high cost of these materials limits their application. In this study, we present the synthesis of Al NPs/g-C3N4 nanocomposites using the bridging effect of ligands. The characterized of transmission electron microscopy (TEM), X-ray diffractometer (XRD) and ultraviolet-visible spectroscopy (UV-Vis) proved that Al NPs/g-C3N4 with a wider light absorption range were successfully synthesized. The effects of ligands, (glutathione (GSH), glutamic acid (GAG), and cysteine (CYS)), Al diameter (40 to 200 nm) and the ratio of Al to g-C3N4 (1:1 to 5:1) on the photocatalytic degradation of methylene blue (MB) by Al NPs/g-C3N4 were also evaluated. The results showed that the optimum degradation efficiency of Al NPs/g-C3N4 for MB at 5 mg/L reached 100% within 60 min, which was 11 times higher than that of pure g-C3N4. The principal analysis of Al enhancing the photocatalytic performance of g-C3N4 was studied through transient photocurrent spectroscopy (TPC), electrochemical impedance spectroscopy (EIS), and steady-state transient fluorescence spectroscopy (PL). The results confirmed that hot carriers generated by localized surface plasmon resonance (LSPR) of Al nanoparticles increase the carrier concentration. In addition, the Schottky barrier generated by Al and g-C3N4 could also improve the carrier separation rate and increase the carrier lifetime. This work is expected to solve the problem of organic wastewater treatment and lay the foundation for subsequent research on photocatalysis. [ABSTRACT FROM AUTHOR]

A high temperature MD effect has been observed in Pr3Fe5O12 (PrIG) which is a new member of rare earth iron garnets (RIG) family. Research indicates that this material has two dielectric relaxations in the temperature range from 370 K to 565 K and a dielectric anomaly around 580 K. The first dielectric relaxation is attributed to the conduction for the similar activation energy with conduction. The other dielectric relaxation in the higher temperature range originated from the inhomogeneous structure. And, the coupling between the ferrimagnetic phase transition and the dielectric response was observed at 1 kHz 0.35 T 580K. [ABSTRACT FROM AUTHOR]

TiO2 is a catalyst that can effectively degrade organic pollutants with the following advantages, low cost, simplicity, and pollution-free nature. In recent years, the non-noble plasmonic metal Al has effectively improved the photocatalytic performance of TiO2. However, the current reports are limited to the photocatalytic performance of Al/TiO2 on the substrate, which requires expensive large-scale vacuum equipment. In this study, monodispersed Al particles were proposed to enhance the photocatalysis of TiO2. The localized surface plasmon resonance (LSPR) effect of Al is proven by finite difference time domain method (FDTF) simulation. Then, Al/TiO2 composites were prepared by combining monodispersed Al and TiO2. The influence of ligand (glutathione (GSH), glutamic acid (GAG), or 3-mercaptopropane acid (MPA)), Al size (40 to 300 nm), and the ratio of Al to TiO2 (0.5:1 to 10:1) on the photocatalytic degradation of methylene blue (MB) by Al/TiO2 were discussed. The obtained results showed that the Al/TiO2 composite which were prepared with 200 nm Al particles, GSH as the ligand bridge, and an Al:TiO2 ratio of 1:1 had the best MB degradation effect. It can degrade 97.7% of 10 mg/L MB in 100 min. The reaction rate of the Al/TiO2 composite with the optimal photocatalytic performance is k=3.36×10-2 min-1, which is 10 times that of P25 TiO2. In addition, Al/TiO2 has a good photocatalytic effect on rhodamine B (RhB) and crystal violet (CV). Therefore, Al/TiO2 composites with the advantage of high efficiency are a type of potential photocatalytic material that can be used for the photocatalytic treatment of organic pollutants in water. [ABSTRACT FROM AUTHOR]

Laser-induced breakdown spectroscopy refers to the radiation spectrum formed by the vaporization and ionization of samples under high-temperature conditions. It is a new technology for detecting and analyzing the composition and content of materials. However, this technology is not yet very mature; in this regard, this paper proposes a quantitative study of atomic spectroscopy using laser-induced technology. On this basis, a method using laser-induced breakdown spectroscopy is proposed, and its quantitative analysis and application are carried out in detail. The laser-induced breakdown technology uses a high-power pulsed laser to form a plasma on the surface of the test piece and analyzes its radiation spectrum to obtain the composition and content of its elements. It also used the laser-induced breakdown technique to quantitatively analyze the Ti-doped Al2O3 ceramic system. Through the quantitative analysis of constant laser and constant plasma temperature, the linear correlation coefficient R2 of the calibration curve calculated with constant plasma temperature is obtained as 0.985, and the relative error is 5.3%. This paper uses a fixed laser pulse amplification voltage, the linear coefficient of the proportional relationship curve is only 0.92, and the error rate is 8.9%. By comparing the two curves, the Ti proportional curve obtained by a fixed plasma temperature is obtained in this paper. Its linearity is better than the Ti scaling curve obtained by constant laser voltage. [ABSTRACT FROM AUTHOR]

In order to facilitate the synthesis of this compound by researchers who are interested in this material, we introduce the specific steps of the synthesis of this material in detail. At the same time, we believe that the geometric error of the sample holder in collecting the crystallographic data of the sample as suspected by the authors of this Comment does not exist. [ABSTRACT FROM AUTHOR]

[Display omitted] Localized surface plasmon resonances of the Al-NPs enhance the photocatalysis performances of Al-NPs/ TiO 2. • Al-NPs/TiO 2 are prepared by using GSH ligand compound as linking bridge. • FDTD simulation reveal the LSPR of 70 nm Al-NPs have a strong coupling with the TiO 2 band gap. • XPS and FTIR measurements confirm that a stable bond formed between Al-NPs and TiO 2. • The LSPR effect of Al-NPs can significantly enhance the photocatalytic efficiency of TiO 2. Al nanoparticles composited with TiO 2 (Al-NPs/TiO 2) has drawn considerable attention over the years due to the localized surface plasmon resonance (LSPR) effect of Al-NPs can significantly enhance the photocatalytic efficiency of TiO 2. However, most of the Al-NPs were obtained on Al substrates which limited its practical application. Herein, the isolated Al-NPs were composited together with the TiO 2 by using glutathione (GSH) as linking bridge in aqueous environment. Finite difference time domain (FDTD) simulation was used to reveal the LSPR absorption of Al-NPs. The results show that the LSPR of 70 nm Al-NPs have a strong coupling with the TiO 2 band gap. The X-ray diffraction analysis and TEM images show that our sample are pure, and the TiO 2 indeed composite on the surface of Al-NPs under the action of GSH ligand bridge as seen in the TEM images. This ligand bridge was further verified by the FTIR and XPS measurements. The EPR experiment indicate the OH signals of Al-NPs/TiO 2 are higher than that of pure TiO 2 because of enhanced charge separation and transfer. The photodegradation experiment show that Al-NPs/TiO 2 can rapidly degrade the concentration of methylene blue (MB) to zero under UV–vis light illumination in 70 min. All the above results indicate that the Al-NPs can significantly enhance the photocatalytic efficiency of TiO 2 which due to the LSPR effect of Al. [ABSTRACT FROM AUTHOR]

The reverse breakdown characteristics of 4H-SiC Junction Barrier Schottky (JBS) rectifiers adopting the different floating limiting rings (FLRs) termination structures are experimented and analyzed under the repetitive avalanche current stress. The experimental results indicate that the breakdown voltage (BV) shift of the device after the repetitive avalanche current stress is highly dependent on the FLRs design, which determines the distributions of the surface electric field and avalanche current at avalanche condition. It is proved that the uniform surface electric field distribution of the FLRs structure at avalanche condition is helpful for the device achieve to achieve better BV shift robustness on the repetitive avalanche current stress. Additionally, the FLRs structure, which has smaller S1 and enough Nr, can present both higher BV and excellent BV shift robustness on the repetitive avalanche current stress. [ABSTRACT FROM AUTHOR]

In this letter, planar floating limiting rings (FLRs) and trench FLRs with different trench depths for the 4H-SiC junction barrier Schottky (JBS) rectifiers are analyzed and compared with simulations and experiments. Compared with the planar FLRs, the experimental results present that the first ring spacing window that termination efficiency exceeds 80% of the parallel plane breakdown voltage (BV) can be widened and termination area can be reduced at the same BV by adopting the trench FLRs. The simulations also indicate that there is an optimal trench depth for the trench FLRs and a smaller sidewall angle can achieve better device performance. Additionally, the repetitive avalanche current stress measurements imply that the trench FLRs has better robustness regarding the BV shift, achieving better device reliability. [ABSTRACT FROM AUTHOR]

A new 3D open-framework potassium ferrite, K2Fe4O7 (1), has been successfully synthesized under hydrothermal conditions. The framework of 1 consists of both FeO6 octahedral and FeO4 tetrahedral units with shared vertices and edges where there are 6- and 3-ring channels parallel to the trigonal a- and c-axes, enabling many highly mobile potassium ions to move quickly through the channels. The K+ ion conductivity of the polycrystalline sample was 5.0 × 10−2 S cm−1 at room temperature. Interestingly, conductivities along the a-axis direction in single crystal K2Fe4O7 reached 3.5 × 102 S cm−1 at 25 °C and 5.0 × 102 S cm−1 at 500 °C with an activation energy of 0.08 eV. The conductor possessed a wide voltage stability up to 5 V vs. K/K+. Using the K2Fe4O7 electrolyte, we demonstrate an all-solid-state potassium metal battery employing a Prussian blue cathode with a high charge/discharge rate of 250C (charge/discharge in 14 s, 1C = 87 mA h g−1). [ABSTRACT FROM AUTHOR]

AgNbO3 is a weak ferroelectric with antiferroelectricity due to Ag displacements at room temperature. A dielectric anomaly at 250 K, which has not been observed previously, reveals a transition between the weak ferroelectric phase (M1 phase) at the higher temperature and a new ferroelectric phase (M0 phase) at the lower temperature in AgNbO3. This transition was further verified by the pyroelectric current and differential scanning calorimetry measurements. The spontaneous polarization value is found to be much larger in the M0 phase than that of the M1 phase. A well-defined saturating ferroelectric hysteresis loop can also be observed at 77 K, showing a remnant polarization value of 2.4 μC/cm2 and a coercive field of 25 kV/cm. All the above results indicate that the larger polarization of the M0 phase mainly comes from the alignment of the antiferroelectric displacements of the Ag atoms. [ABSTRACT FROM AUTHOR]

AgNbO3 is a weak ferroelectric with antiferroelectricity due to Ag displacements at room temperature. A dielectric anomaly at 250 K, which has not been observed previously, reveals a transition between the weak ferroelectric phase (M1 phase) at the higher temperature and a new ferroelectric phase (M0 phase) at the lower temperature in AgNbO3. This transition was further verified by the pyroelectric current and differential scanning calorimetry measurements. The spontaneous polarization value is found to be much larger in the M0 phase than that of the M1 phase. A well-defined saturating ferroelectric hysteresis loop can also be observed at 77 K, showing a remnant polarization value of 2.4 μC/cm2 and a coercive field of 25 kV/cm. All the above results indicate that the larger polarization of the M0 phase mainly comes from the alignment of the antiferroelectric displacements of the Ag atoms. [ABSTRACT FROM AUTHOR]

The orthoferrite YFeO3 with orthorhombic perovskite structure (Pnma) has been synthesized by mild hydrothermal method. The temperature-dependent magnetization and hysteresis loops indicate that, due to the superexchange and Dzyaloshinskii-Moriya interactions in the crystals, the Fe spins order antiferromagnetically at the Néel temperature 655 K with a weak ferromagnetic moment. The observation of saturation polarization loops at room temperature and 77 K provide evidence for the ferroelectric character of the polycrystalline samples. Its Curie temperature has been obtained from the temperature dependence of the relative permittivities and thermal analysis. As a result, the structure exhibits simultaneously weak ferromagnetic and ferroelectric behavior. [ABSTRACT FROM AUTHOR]

The title compound is hydrothermally prepared from a solution of Y(NO3)3, NiSO4, MnO2, and KOH (autoclave, 533 K, 3 d) and characterized by powder XRD, SEM, XPS, and electric and magnetic measurements. [ABSTRACT FROM AUTHOR]