期刊：
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY,2025年88:102791 ISSN：0364-5916
通讯作者：
Du, Y;Fabrichnaya, O
作者机构：
[Du, Yong; Yang, Lianfeng; Liu, Yuling] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.;[Zeng, Yinping] Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Changsha 410114, Peoples R China.;[Fabrichnaya, Olga] TU Bergakad Freiberg, Inst Mat Sci, D-09599 Freiberg, Germany.;[Zhang, Ligang] Cent South Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.
通讯机构：
[Du, Y ] C;[Fabrichnaya, O ] T;Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.;TU Bergakad Freiberg, Inst Mat Sci, D-09599 Freiberg, Germany.
关键词：
Phase diagram;Two-sublattice partially ionic liquid model;CALPHAD;The Na2O-SiO2 system
摘要：
Thermodynamic investigation of the Na 2 O-SiO 2 system is extremely significant for the silicate glass industry and the control of Na 2 O balance in the input materials of blast furnaces. The Na 2 O-SiO 2 system has been thermodynamically assessed numerous times in the previous studies. However, the phase equilibria in the Na 2 O-rich side remain inadequately described. Consequently, the Na 2 O-SiO 2 system was reassessed by the CALPHAD approach in the present work. The liquid phase was described by using the two-sublattice partially ionic liquid model (Na +1 ) P (O −2 ,SiO 4 −4 ,SiO 2 ) Q and six intermediate compounds were treated as stoichiometric compounds due to their limited solid solubilities. A set of self-consistent thermodynamic parameters was then obtained, and the experimental phase diagram data and thermodynamic properties can be satisfactorily reproduced by the calculation within the experimental errors. The present thermodynamic parameters contribute to the composition design of silicate glass and the formulation of input materials in blast furnaces.
Thermodynamic investigation of the Na 2 O-SiO 2 system is extremely significant for the silicate glass industry and the control of Na 2 O balance in the input materials of blast furnaces. The Na 2 O-SiO 2 system has been thermodynamically assessed numerous times in the previous studies. However, the phase equilibria in the Na 2 O-rich side remain inadequately described. Consequently, the Na 2 O-SiO 2 system was reassessed by the CALPHAD approach in the present work. The liquid phase was described by using the two-sublattice partially ionic liquid model (Na +1 ) P (O −2 ,SiO 4 −4 ,SiO 2 ) Q and six intermediate compounds were treated as stoichiometric compounds due to their limited solid solubilities. A set of self-consistent thermodynamic parameters was then obtained, and the experimental phase diagram data and thermodynamic properties can be satisfactorily reproduced by the calculation within the experimental errors. The present thermodynamic parameters contribute to the composition design of silicate glass and the formulation of input materials in blast furnaces.
摘要：
Enhancing light-matter interactions is particularly important in the field of micronano optics, which can be achieved through plasmon-induced transparency. A new type of metasurface consisting of a single layer of graphene is mainly investigated in the study. This structure is mainly composed of a graphene strip and two graphene blocks, generating plasmon-induced transparency at terahertz frequencies via weak coupling between the two bright modes. Furthermore, the time-domain finite-difference method (FDTD) and coupled-mode theory (CMT) are utilized to further explore the physical mechanism of PIT formation. By adjusting the Fermi level of graphene, the transmittance window of PIT can be effectively regulated, resulting in a reflectivity of more than 65% for this structure. Moreover, the influence of the graphene Fermi level on the slow-light effect was analyzed, and the group index was increased from 450 to 562 when the Fermi level of graphene was increased from 0.8 eV to 1.1 eV. The findings are important for the realization of multifunctional terahertz devices such as modulators and slow light. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.
关键词：
heat transfer simulation model;quartz flexible accelerometer;temperature field;unsteady heat conduction
摘要：
Quartz flexible accelerometers (QFAs) are a type of temperature-sensitive sensor, whereby a change in temperature will cause the key parameters of the accelerometer to drift and cause stability errors. Due to the absence of effective methods for sensing the temperature of internal accelerometer components, existing temperature error correction approaches primarily rely on shell temperature measurements to establish correction models. Consequently, most correction methods achieve higher accuracy during the steady-state heat conduction phase of the accelerometer, whereas the correction error markedly increases during the transient heat conduction phase. To elucidate the temperature discrepancy between the QFA shell and its internal components and to support the development of a temperature error correction method for QFAs based on the internal temperature as a reference, this paper investigated the heat exchange dynamics between the interior and exterior of a QFA. A thermal conduction simulation model of the QFA was established, from which the spatiotemporal distribution patterns of the internal temperature field were derived. The results indicate that the temperature of the QFA shell changes significantly faster than that of the internal meter head in the early stage of the temperature change. The temperature gradient between the shell and the meter head first increases and then decreases, and the rate of temperature change in the upper part of the accelerometer is faster than that in the lower part. Before thermal equilibrium is reached, the temperature distribution inside the accelerometer is uneven in terms of time and space. Inside the accelerometer, the yoke iron, swing plate assembly, servo circuit, and magnetic steel assembly are the main components that exhibit differences in the internal temperature change in the QFA. When developing the temperature error correction method, it was crucial to address and mitigate the impact of temperature variations among these components. The average RMSE between the predicted temperature from the heat transfer model established in this paper and the experimental results was 0.4 °C. This indicates that the model can accurately predict the temperature variation within the QFA, thereby providing robust support for investigating the temperature behavior inside the QFA and offering essential technical foundations for enhancing the accuracy of the temperature error correction method.
摘要：
Deep learning-based dMRI super-resolution methods can effectively enhance image resolution by leveraging the learning capabilities of neural networks on large datasets. However, these methods tend to learn a fixed scale mapping between low-resolution (LR) and high-resolution (HR) images, overlooking the need for radiologists to scale the images at arbitrary resolutions. Moreover, the pixel-wise loss in the image domain tends to generate over-smoothed results, losing fine textures and edge information. To address these issues, we propose a novel continuous super-resolution method for dMRI, called CSR-dMRI, which utilizes an anatomical structure-assisted implicit neural representation learning approach. Specifically, the CSR-dMRI model consists of two components. The first is the latent feature extractor, which primarily extracts latent space feature maps from LR dMRI and anatomical images while learning structural prior information from the anatomical images. The second is the implicit function network, which utilizes voxel coordinates and latent feature vectors to generate voxel intensities at corresponding positions. Additionally, a frequency-domain-based loss is introduced to preserve the structural and texture information, further enhancing the image quality. Extensive experiments on the publicly available HCP dataset validate the effectiveness of our approach. Furthermore, our method demonstrates superior generalization capability and can be applied to arbitrary-scale super-resolution, including non-integer scale factors, expanding its applicability beyond conventional approaches.
作者机构：
[Huihui Huang] Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University , Changsha 410082, China;[Yaocheng Yang] Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology , Changsha 410114, China
通讯机构：
[Huihui Huang] K;Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University , Changsha 410082, China
摘要：
Wearable thermoelectric generators (WTEGs) are of significance in the conversion of body heat into electricity for the purpose of powering wearable electronic devices. Two-dimensional (2D) transition metal dichalcogenides (TMDCs) exhibit exceptional thermoelectric power factors and mechanical stability, making them promising flexible thermoelectric materials. However, the output voltage of the present TMDC-based WTEGs remains at a relatively low level. In this study, we precisely modulate the electronic structure of titanium disulfide (TiS 2 ) nanosheets in a restacked film by surface modification, leading to the decoupling phenomenon of a simultaneous rise in the electrical conductivity and the Seebeck coefficient. This method enhances the thermoelectric power factor by approximately 14 times compared to pre-modified samples. We fabricated a flexible self-reassembly WTEG using 1T-phase molybdenum disulfide (MoS 2 ) nanosheets as p -type material and modified TiS 2 nanosheets as an n -type material. The generator achieved a voltage output of approximately 15 mV while harvesting heat from the human arm, showcasing its potential for practical applications.
摘要：
Covalent organic frameworks (COFs) exhibit considerable potential in gas separations owing to their remarkable stability and tunable pore structures. Nevertheless, their application as gas separation membranes is hindered by limited size-sieving capabilities and poor processability. In this study, we propose a novel molecular weaving strategy that combines hydroxyl polymers and 2D TpPa−SO 3 H COF nanosheets, achieving high gas separation efficiency. Driven by the strong electrostatic interactions, the hydroxyl chains thread through the COF pores, effectively weaving and assembling the composites to achieve exceptional flexibility and high mechanical strength. The penetrated chains also reduce the effective pore size of COFs, and combined with the “secondary confinement effect” stemming from abundant CO 2 sorption sites in the channels, the PVA@TpPa−SO 3 H membrane demonstrates a remarkable H 2 permeance of 1267.3 GPU and an H 2 /CO 2 selectivity of 43, surpassing the 2008 Robson upper bound limit. This facile strategy holds promise for the manufacture of large-area COF-based membranes for small-sized gas separations.
作者机构：
[Jiajian He; Wei Mei; Lianghua Hu; Likai Ou; Yaoyang Lian; Mingan Chen; Liuming Dou] Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114, China
通讯机构：
[Liuming Dou] H;Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114, China
摘要：
With the increase of integration, the smaller the scale of FETs, the performance of silicon-based FETs will be limited, and two-dimensional FETs will become inevitable. In this paper, the transfer characteristics and performances of 5.1 nm, 6.1 nm 1 T/2H/1 T MoTe 2 and WSe 2 single-layer dual-gate Schottky barrier field effect transistor (D-SBFET) were discussed, and it was found that only the ON-state current of 6.1 nm MoTe 2 -D-SBFET met the ON-state current requirement of ITRS, and the others were all lower than ITRS requirement. In order to improve the ON-state current, a new layered triple-gate structure SBFET (T-SBFET) was constructed. The study found that the new T-SBFET increases the ON-state current due to the increase of its transport coefficient, and the performance of all 5.1 nm and 6.1 nm MoTe 2 -T-SBFETs or WSe 2 -T-SBFETs meet the requirements of ITRS. This study shows that it is a good method to construct a triple-gate structure to increase the ON-state current of two-dimensional devices.
With the increase of integration, the smaller the scale of FETs, the performance of silicon-based FETs will be limited, and two-dimensional FETs will become inevitable. In this paper, the transfer characteristics and performances of 5.1 nm, 6.1 nm 1 T/2H/1 T MoTe 2 and WSe 2 single-layer dual-gate Schottky barrier field effect transistor (D-SBFET) were discussed, and it was found that only the ON-state current of 6.1 nm MoTe 2 -D-SBFET met the ON-state current requirement of ITRS, and the others were all lower than ITRS requirement. In order to improve the ON-state current, a new layered triple-gate structure SBFET (T-SBFET) was constructed. The study found that the new T-SBFET increases the ON-state current due to the increase of its transport coefficient, and the performance of all 5.1 nm and 6.1 nm MoTe 2 -T-SBFETs or WSe 2 -T-SBFETs meet the requirements of ITRS. This study shows that it is a good method to construct a triple-gate structure to increase the ON-state current of two-dimensional devices.
关键词：
asymmetry;auroral kilometric radiation;interplanetary magnetic field
摘要：
Auroral Kilometric Radiation (AKR) is a common radio emission, which can contribute to the magnetosphere-ionosphere-atmosphere coupling. Similar emissions have been observed in all magnetic planet magnetospheres of the solar system. In this study, using observations from the FAST satellite from 30 August 1996 to 9 September 2001, the distribution of AKR in altitude = 500-4500 km and invariant latitude (|ILAT|) = 60 degrees-80 degrees has been analyzed. 63045 AKR samples have been identified with similar to 48% (52%) samples on the dayside (nightside). Of considerable interest, there is a distinct MLT asymmetry with the high occurrence rate in MLT = 05-08 and 18-22 (02-05 and 12-17) in the northern (southern) hemisphere. The distinct MLT asymmetry is associated with the direction of of the interplanetary magnetic field. In addition, the occurrence rate on the nightside clearly increases as the index increases. This study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions.
关键词：
Single image dehazing;Multi-scale feature;Parallel depth-wise large convolutions;Triplet attention
摘要：
Single image dehazing is a fundamental yet challenging task in computer vision. Many studies aim to improve learning-based methods by constructing deep residual networks with multiple small convolutional kernels and attention mechanisms. However, these methods encounter two major limitations. First, small convolutional kernels in redundant layers of deep residual networks may not train effectively, restricting the receptive field’s expansion. Second, haze impacts image information across three dimensions, necessitating consideration of their interrelationships in attention mechanism design for dehazing networks. Most existing methods analyze these dimensional relationships separately, which diminishes their effectiveness in the dehazing task. To address these challenges, this paper introduces the Multi-Scale Large Convolution Triple Attention Network (MLCTA-Net) within the U-Net framework. The proposed architecture consists of two primary modules: the multi-scale feature extraction unit utilizing parallel depth-wise large convolutions, and the triple attention unit with three branches that enhance interactions among single-dimensional information and the other two dimensions. By utilizing large convolutional kernels, MLCTA-Net effectively expands the receptive field, facilitating a more comprehensive understanding of image information. Furthermore, the attention mechanism, designed through interactions among dimensional information and parallel connections, better aligns with the multidimensional effects of haze on image information. Extensive experimental evaluations validate the effectiveness of the proposed method. Compared to the MAXIM-2 S and Dehamer networks, MLCTA-Net achieves PSNR improvements of 3.85 dB and 0.71 dB on the SOTS-indoor and SOTS-outdoor test datasets, respectively, while utilizing only 1.65 million parameters.
摘要：
Remote sensing image change detection (RSCD) aims to identify differences between remote sensing images of the same location at different times. However, due to the significant variations in the size and appearance of objects in real-world scenes, existing RSCD algorithms often lack strong capabilities in extracting multiscale features, thereby failing to fully capture the characteristics of changes. To address this issue, a multiscale remote sensing change detection network (MSNet) and a multiscale RSCD dataset (MSRS-CD) are proposed. A multiscale convolution module (MSCM) is investigated, and combined with MSCM, an encoder capable of capturing features of different sizes is designed to efficiently extract multiscale semantic change features. A global multiscale feature fusion module is designed to achieve global multiscale feature fusion and obtain multiscale high-level semantic change features. As existing RSCD datasets lack rich scale information and often focus on change targets of specific sizes, a new dataset, MSRS-CD, is constructed. This dataset consists of 842 pairs of images with a resolution of 1024 × 1024 pixels, featuring uniformly distributed change detection target sizes. Comparative experiments are conducted with 10 other state-of-the-art algorithms on the MSRS-CD dataset and another public dataset, LEVIR-CD. Experimental results demonstrate that MSNet achieves the best performance on both datasets, with an F1 score of 75.74% on the MSRS-CD dataset and 91.41% on the LEVIR-CD dataset.
摘要：
Defects in printed circuit boards (PCBs) can degrade the performance and reliability of electronic devices. Although YOLOv5-based algorithms are commonly used to detect PCB defects, their complex parameters slow down detection speeds on industrial platforms. This paper presents a lightweight, high-performance model for PCB defect detection, called Align Soft-Target Knowledge Distillation PCB Lightweight Defect Detection (ASTKD-PCB-LDD). The model uses the k-means++ algorithm for optimal anchor box selection and the SCYLLA-IoU (SIoU) loss function to improve accuracy in detecting small defects. The Faster-Ghost backbone network and slim-neck architecture reduce computational load and improve inference speed. Additionally, Align Soft-Target Knowledge Distillation (ASTKD) is applied, with the PCB-LDD model as the teacher and a pruned model-created using Layer-Adaptive Magnitude-based Pruning (LAMP)-as the student. This strategy helps to maintain detection accuracy while reducing model size. Experimental results show that the model size is reduced from 14.5 to 4 MB (a 27.6%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} reduction), achieving 98%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} mean average precision (mAP), and the detection speed increases from 73.2 frames/s to 112.3 frames/s, improving by 153.4%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document}. Moreover, the model demonstrates strong applicability and scalability. This approach effectively combines performance and lightweight design, significantly enhancing PCB defect detection efficiency.
作者机构：
[Tong-Hui Zhou; Lin Long] Department of Mathematics and Physics, Chongqing College of Mobile Communication, Chongqing, 401520, China;[Zhi-Qiang Fan] School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114, China
通讯机构：
[Lin Long] D;Department of Mathematics and Physics, Chongqing College of Mobile Communication, Chongqing, 401520, China
摘要：
The paper studies the mechanical force adjusting the bonding orientation with respect to the molecule to regulate electronic transport in single-molecule devices by using first-principle calculations. We designed molecular junctions by connecting tetraphenylene molecules to gold electrodes via amino or pyridine anchoring groups. By applying horizontal compressive force, the bonding orientation angle was adjusted from 0° to 45°, and the corresponding current-voltage characteristics were calculated. For the single-molecule device connected to gold electrodes via amino group, the transmission spectra exhibited a pronounced leftward shift as the orientation angle increased, accompanied by a gradual rise in the current. In contrast, the single-molecule device connected to gold electrodes via pyridine group showed no significant shift in the transmission spectra under mechanical compression. When the orientation angle increases to 30° and 45°, significant negative differential resistance behaviors are observed in the molecular devices. Our research results provide an understanding of the influence of bonding orientation on the electronic transport properties in molecular devices, and offering an approach to the realization of molecular functional devices.
The paper studies the mechanical force adjusting the bonding orientation with respect to the molecule to regulate electronic transport in single-molecule devices by using first-principle calculations. We designed molecular junctions by connecting tetraphenylene molecules to gold electrodes via amino or pyridine anchoring groups. By applying horizontal compressive force, the bonding orientation angle was adjusted from 0° to 45°, and the corresponding current-voltage characteristics were calculated. For the single-molecule device connected to gold electrodes via amino group, the transmission spectra exhibited a pronounced leftward shift as the orientation angle increased, accompanied by a gradual rise in the current. In contrast, the single-molecule device connected to gold electrodes via pyridine group showed no significant shift in the transmission spectra under mechanical compression. When the orientation angle increases to 30° and 45°, significant negative differential resistance behaviors are observed in the molecular devices. Our research results provide an understanding of the influence of bonding orientation on the electronic transport properties in molecular devices, and offering an approach to the realization of molecular functional devices.
摘要：
This article uses first principles calculations to study the electronic transport properties of two-dimensional materials germanium selenide (GeSe), tin sulfide (SnS), and their SnS/GeSe van der Waals heterostructures for adsorbing three sulfur gases. Through total energy calculations, we determined that H 2 S and SO 2 tend to adsorb more readily to the vacancies on the surfaces of GeSe, SnS, and the SnS/GeSe heterojunctions, whereas SO 3 shows a stronger preference for adsorbing to the top sites. By analyzing the band structure of sulfur gases after adsorption, we found that H 2 S adsorption has no regulatory effect on the electronic structure of monolayers and heterojunctions, but the adsorption of SO 2 and SO 3 can regulate the electronic structure of monolayers and heterojunctions to varying degrees. Among them, the adsorption of SO 2 most significantly modulates the band structure, not only adjusting the position of energy distribution within the band structure but also inducing new energy band. Therefore, we constructed a gas sensing device based on SnS/GeSe heterojunction and focused on studying the electronic transport properties before and after SO 2 adsorption. The device without gas adsorption consistently exhibit very small currents within the bias voltage range of −0.7 V to 0.7 V. However, the adsorption of SO 2 notably enhances the current of the device and displays a negative differential resistance effect in both positive and negative bias region, with a peak-to-valley ratio approaching 300. Therefore, we conclude that SnS/GeSe heterojunction devices can serve as gas sensitive adsorption detection devices for SO 2 , which has important physical significance for further understanding the electronic transport mechanism of molecular devices.
This article uses first principles calculations to study the electronic transport properties of two-dimensional materials germanium selenide (GeSe), tin sulfide (SnS), and their SnS/GeSe van der Waals heterostructures for adsorbing three sulfur gases. Through total energy calculations, we determined that H 2 S and SO 2 tend to adsorb more readily to the vacancies on the surfaces of GeSe, SnS, and the SnS/GeSe heterojunctions, whereas SO 3 shows a stronger preference for adsorbing to the top sites. By analyzing the band structure of sulfur gases after adsorption, we found that H 2 S adsorption has no regulatory effect on the electronic structure of monolayers and heterojunctions, but the adsorption of SO 2 and SO 3 can regulate the electronic structure of monolayers and heterojunctions to varying degrees. Among them, the adsorption of SO 2 most significantly modulates the band structure, not only adjusting the position of energy distribution within the band structure but also inducing new energy band. Therefore, we constructed a gas sensing device based on SnS/GeSe heterojunction and focused on studying the electronic transport properties before and after SO 2 adsorption. The device without gas adsorption consistently exhibit very small currents within the bias voltage range of −0.7 V to 0.7 V. However, the adsorption of SO 2 notably enhances the current of the device and displays a negative differential resistance effect in both positive and negative bias region, with a peak-to-valley ratio approaching 300. Therefore, we conclude that SnS/GeSe heterojunction devices can serve as gas sensitive adsorption detection devices for SO 2 , which has important physical significance for further understanding the electronic transport mechanism of molecular devices.
摘要：
We conducted observational studies of ionospheric responses to the geomagnetic storm on 12 May 2021. We selected three cases that the electron density altitude profiles observed by Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) exhibited significant longitudinal differences in less than 30° longitudes. These cases occurred over the Atlantic Ocean and during the storm's recovery phase. All three cases show relatively weaker variations on the west side between disturbed and quiet time (<10%), while displaying pronounced positive/negative electron density variations on the east side (as large as 100%). GOLD and ICON observations illustrate that the thermospheric composition plays a minor role in the longitudinal differences, while neutral winds and disturbed electric fields make major contributions. Furthermore, significant longitudinal differences in E×B drift and neutral winds have also been observed, which will be part of the future work. This study provides unique insights into ionospheric responses within 30-degree longitude range over the ocean.
Strong differences of electron density occurring in <30° longitude were studied by COSMIC-2, Global Scale Observations of the Limb and Disk, and Ionospheric Connection Explorer
All three cases occurred over the ocean and exhibited much stronger relative variations during disturbed time in the east than in the west
Thermospheric composition plays minor role, while neutral wind and electric field make major contributions to the longitudinal differences
Ionospheric longitudinal difference refers to the difference in electron density at different longitudes of the same latitude. Most studies on longitudinal differences have focused on longitudinal differences between different continents during geomagnetically quiet time or geomagnetic storm. Here, we reported the significant east-west longitudinal differences of electron profiles occurring in less than 30° longitude during the geomagnetic storm on 12 May 2021 based on observations from one low-earth orbiting (LEO) satellite. We selected three cases in the mid-latitude over the Atlantic ocean during the recovery phase. We found relative weaker storm time responses on the west side (∼10%), while much stronger variations occur on the eastside (up to 100%). Observations from a geo-stationary satellite indicated that thermospheric composition played a minor role in the longitudinal differences. However, as uncovered by another LEO satellite, the transports due to neutral winds and electric fields significantly affected the differences.
关键词：
meridional winds in F region;ICON /MIGHTI observations;solar minimum solstices;TIEGCM simulations;during quiet time;local time dependency
摘要：
ICON observations were used to investigate local time (LT) and latitudinal variations of thermospheric meridional winds in the middle-high thermosphere (160–300 km) during quiet times in 2020 June and December. At middle-low latitudes (10°S–40°N), meridional winds were predominantly equatorward in the summer hemisphere while mostly poleward in the winter hemisphere. The meridional winds showed that the diurnal variation was dominant between ∼20°N and ∼40°N, but the semi-diurnal variation played a leading role at lower latitudes (below ∼20°N) during solstice months. Thermosphere-Ionosphere Electrodynamics General Circulation Model reproduced the ICON observed meridional wind variations qualitatively. A model diagnostic analysis shows that the pressure gradient force dominated the semi-diurnal variation of the winds, while the Coriolis force played a leading role in the diurnal variation in June. In December, LT variations of meridional winds were primarily driven by pressure gradient and ion drag forces. During both months, the vertical viscosity was important, tending to balance the effects of pressure gradients. Additionally, semi-diurnal variations of low-latitude meridional winds in June were more affected by upward propagating tides than those in December.
ICON-observed F-layer meridional winds show that diurnal and semidiurnal variations dominate at ∼20°N–40°N and 10°S–∼20°N respectively
In June, pressure gradient force dominated the semi-diurnal variation, and Coriolis force had a leading role in the diurnal variation
Semi-diurnal variations of meridional winds at low latitudes in June were more affected by upward propagating tides than those in December
摘要：
PurposeElliptical ultrasonic vibration is an essential auxiliary method for reducing milling forces and temperatures during machining processes. Rapidly determining the optimal geometric parameters of elliptical ultrasonic transducers for achieving effective vibration is of paramount significance.MethodsThis paper introduces a geometric modeling method for elliptical ultrasonic vibration piezoelectric transducers based on transfer matrice and convolutional neural network (CNN). The method employs the transfer matrix method to establish a composite beam bending vibration model of the transducer and constructs a dataset of the electromechanical coupling coefficient (ke\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k_e$$\end{document}) for the piezoelectric ceramic in the X-direction (X-PZT), which corresponds to the transducer model parameters, including the length of the tail mass, the length of the X-PZT, and the length and diameter of the horn. CNN trained the dataset to obtain the ke\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k_e$$\end{document} objective function. The Non-Dominated Sorting Genetic Algorithm (NSGA) is used to find the optimal solution for the objective function.ResultsThe results indicate that this method efficiently attains the optimal 2nd-order bending vibration ke value of the transducer to be 21.7%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} , with a corresponding ke\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k_e$$\end{document} value of 22.6%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} achieved through finite element simulation, resulting in an error of 0.9%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document}. Furthermore, field displacement (Amp\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$A_{mp}$$\end{document}) and impedance model (|Z|) curves for various transducer bending vibrations were obtained, demonstrating that the error associated with the 2nd-order theoretical analyses and finite element simulation results is less than that of the 1st-order, with the maximum error in the 2nd-order ke\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k_e$$\end{document} not surpassing 4.5%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document}.ConclusionDesign and implementation of an elliptical ultrasonic vibrational transducer were carried out based on the theoretical and simulation studies. The effectiveness of the theoretical model and simulations was experimentally validated through impedance analysis.
期刊：
OPTICS AND LASER TECHNOLOGY,2025年181:111602 ISSN：0030-3992
通讯作者：
Qingjie Liu
作者机构：
[Wang, Tiantian; Liu, Qingjie; Ao, Yingquan] College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China;[Li, Tong] School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410114, China
通讯机构：
[Qingjie Liu] C;College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China
摘要：
In non-Hermitian systems, the singularities refer to poles or zeros of the scattering and transfer matrices. Here, we investigate the kinds of singularities in a non-parity-time-symmetric multilayer structure which mainly consists of double layers of silver grating and one layer of phase-change material Ge2Sb2Te5 (GST). When the GST is in its crystalline phase, a unidirectional zero-reflection singularity, i.e., exceptional point (EP) is achieved with the aid of Fano resonance. Interestingly, a coherent perfect absorber (CPA)-laser singularity adjacent to the EP is observed in the Fano peak. Meanwhile, a few CPA singularities exist at other wavelengths. By switching the GST from its crystalline to amorphous phase, the CPA-laser singularity will be absent, and the CPA singularity can be switched to a laser singularity. The scattering spectra near the singularities are sensitive to a tiny perturbation of the gain material and the environmental refractive index. The study is beneficial for making switchable active optical implementations.
摘要：
Developing a catalytic nanoenzyme activated by the tumor microenvironment (TME) shows excellent potential for in situ cancer treatment. However, the rational design of a cascade procedure to achieve high therapeutic efficiency remains challenging. In this study, the colorectal TME-responsive multifunctional cascade nanoenzyme Cu(2-x)O@MnO(2)@glucose oxidase (GOx)@hyaluronic acid (HA) was developed to target in situ cancer starvation/chemodynamic therapy (CDT)/photothermal therapy (PTT). First, the MnO(2) nanolayer specifically decomposes within the acidic TME to generate Mn(2+) and oxygen (O(2)), thereby alleviating the hypoxic TME. Subsequently, Cu(2-x)O can be vulcanized into Cu(2-x)S by overexpressing sulfuretted hydrogen (H(2)S) gas in the colorectal tumor for a second near-infrared (NIR-II) light-triggered deep tissue PTT. Cu(2-x)S nanoparticles can react with hydrogen peroxide (H(2)O(2)) to generate hydroxyl radical (OH) for the CDT. In addition, GOx catalyzes the conversion of glucose into H(2)O(2) for starvation therapy and enhances the CDT efficiency by self-supplying H(2)O(2). Interestingly, the generated reactive oxygen species (ROS) induce immunogenic cell death (ICD), which further activates adaptive cancer immunity for anti-tumor immunotherapy. Finally, therapeutic efficiency was greatly improved after coating with tumor-targeted HA. Collectively, these TME-responsive cascade nanoenzymes can realize PTT, CDT starvation therapy, and immunotherapy, paving the way for the design of TME-responsive cascade nanoenzymes for synergistically enhanced tumor-specific therapy.
摘要：
This study investigates the humidity-sensing properties of two semiconductor metal oxide (SMO)-reduced graphene oxide (RGO) nanocomposites: TiO(2)/RGO and α-Fe(2)O(3)/RGO, at room temperature. Both nanocomposites are synthesized via hydrothermal methods and coated onto printed circuit board (PCB) interdigital electrodes to construct humidity sensors. The surface morphology and crystallographic structure of the materials are characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The sensors are tested across a humidity range of 11%RH to 97%RH, and the impedance is measured over a frequency range of 1 Hz to 1 MHz. The results show that both TiO(2)/RGO and α-Fe(2)O(3)/RGO exhibit favorable humidity-sensing performance at room temperature. The sensitivity and humidity hysteresis of TiO(2)/RGO are 12.2 MΩ/%RH and 3.811%RH, respectively, while those of α-Fe(2)O(3)/RGO are 0.826 MΩ/%RH and 8.229%RH. The response and recovery times of TiO(2)/RGO are 72 s and 99 s, respectively, while those of α-Fe(2)O(3)/RGO are 48 s and 54 s. Both sensors demonstrate good repeatability and stability. These findings suggest that SMO/RGO nanocomposites are promising materials for the development of low-cost, high-sensitivity, and stable humidity sensors.
