摘要：
Electron cyclotron harmonic (ECH) waves, which are responsible for the diffuse aurora, are usually observed with the strongest intensity in the first band. Here, we present observations of enhanced higher-band ECH with wave intensities above 10(-3) mV(2)m(-2) Hz(-1) by Van Allen Probes. Fully thermal simulation results indicate that these waves can be locally excited by the observed electron distributions, and higher plasma density and lower magnetic strength are favorable for generating the enhanced higher-band ECH. The pitch angle diffusion coefficient < D-alpha alpha > of the higher-band ECH can exceed 10(-5) s(-1) inside the loss cone for energetic electrons (300 eV-similar to 15 keV), greater than the momentum diffusion coefficient < D-pp > by similar to 100 times. It is suggested that the enhanced higher-band ECH can also efficiently scatter these electrons into the loss cone and contribute to the diffuse aurora. Plain Language Summary Electron cyclotron harmonic (ECH) waves are electrostatic emissions usually observed with the strongest intensity in the first band. Numerous works have demonstrated that the first-band ECH waves can be responsible for diffuse auroral electron precipitation. However, so far the role of higher-band ECH waves has not been confirmed. Here, we report an enhanced higher-band ECH event with wave intensities above 10(-3) mV(2)m(-2) Hz(-1) from Van Allen Probes. Using the realistic parameters, we conduct fully thermal simulations to investigate the generation of such ECH. The results indicate that growth rates can well reproduce the observed wave spectral characteristics in all four harmonic bands, and the higher density and lower magnetic field strength are favorable for generating enhanced higher-band ECH. We calculate the diffusion coefficients to estimate the effect of the higher-band ECH on electrons. The pitch angle diffusion coefficients induced by higher-band ECH are similar to 2 orders of magnitude greater than the momentum diffusion coefficients over a broad pitch angle range and exceed 10(-5) s(-1) inside the loss cone for energetic electrons. This indicates that the enhanced higher-band ECH can also efficiently scatter these energetic electrons into the loss cone and potentially contribute to the diffuse aurora, similar to the first-band ECH.
关键词：
pulsatile photoelectric therapy;neuromorphic device;reconfigurable memorizing and forgetting;visual memory consolidation;amnesia
摘要：
Amnesia is a common clinical disorder manifested by the loss of recent memory as well as global impairment in the ability to acquire new memories, which seriously affects normal life activities of humans. At present, although herbal intervention, protein synthesis inhibition, and hormone replacement can prevent or reverse amnesia, these treatments are relatively expensive and inefficient. Here, an advanced photoelectric-synergistically pulsatile therapy is used to emulate the treatment of visual amnesic behaviors using a zero-dimensional (0D)-carbon-quantum-dots/2D-MoS2 mixed-dimensional heterojunction transistor. The photoelectric pulse could induce enough electrons to fill the trap states and accumulate at the mixed-dimensional interface. The significant biological behaviors, such as reconfigurable memorizing/forgetting behaviors and adjustable visual memory consolidation, are successfully realized in the device. More importantly, the photoelectric-synergistically pulsatile therapy for the effective treatment of visual amnesia is experimentally demonstrated for the first time. These results may provide promising opportunities for the development of medical memory diagnosis systems and human-machine realtime interactions, etc.
期刊：
JOURNAL OF GEOPHYSICAL RESEARCH: SPACE PHYSICS,2023年128(2):e2022JA031089- ISSN：2169-9380
通讯作者：
ChaoLing Tang
作者机构：
[ChaoLing Tang] Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, China;[Chang Yang] School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha, China;[JiChun Zhang] Staunch Data Analytics Lab, Durham, NH, USA;[JingRun Chen; Xu Wang] School of Space Science and Physics, Shandong University, Weihai, China;[ZhengPeng Su] CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei, China
通讯机构：
[ChaoLing Tang] S;Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, China
摘要：
Using the data from Van Allen Probe A and B, we investigate rapid enhancements of relativistic electrons in the Earth's outer radiation belt caused by the intense substorms (AEmax > ∼900 nT) for 29 events from January 2013 to April 2015. These intense substorms may occur during the storm main phase or recovery phase. Based on the different substorm evolution characteristics, the intense substorms are divided into non-continuous intense substorm activities and continuous intense substorm activities. In this study, we set a criterion for rapid enhancements when the electron phase space densities for μ = 1,096, 2,290, and 3,311 MeV/G increased by more than two times in 9 hr. In the time interval of 9 hr, the local acceleration by chorus waves is the dominant process for accelerating the seed populations (hundred kiloelectron volts) up to MeV energies. Our statistical results show that enhanced chorus waves and seed electrons during the intense substorms are observed in the outer radiation belt. Continuous intense substorm activities can more rapidly (<9 hr) and efficiently accelerate relativistic electrons in the outer radiation belt than non-continuous intense substorm activities. During the intense substorms, the electric field acceleration could contribute to rapid enhancements of relativistic electrons in the outer radiation belt. Our statistical study suggests that the intense substorms during geomagnetic storms have a significant effect on the rapid variations of relativistic electron dynamics.
The statistical study of rapid enhancements of MeV electrons in the outer radiation belt caused by the intense substorms is presented
Local acceleration during continuous intense substorms can accelerate electrons to relativistic energies more rapidly and efficiently
The electric field acceleration could contribute to rapid enhancements of MeV electrons in the outer radiation belt
摘要：
The induced voltage generated by lightning electromagnetic (EM) field often damages photovoltaic (PV) panels. To address this issue, a novel solar-cell string wiring is proposed. By the crossover connection of solar-cell strings, the induced voltages are offset by each other. The lightning EM transient of PV array installed on flat ground is computed by using the method of moments. Compared with the conventional wiring, the proposed wiring can not only reduce the induced voltages of most PV panels but also the voltage between the outputs of PV array. The proposed wiring is highly recommended to be used in the PV array on the soil with great resistivity. Moreover, the effect of the proposed solar-cell string wiring on rooftop PV array is assessed. The results indicate that the rooftop PV array with the proposed wiring has a minimum induced voltage. This novel solar-cell string wiring does not require additional protection devices and is easy to implement.
摘要：
Both two-dimensional (2D) graphene (G) and layered double hydroxides (LDHs) nanomaterials can form excellent heterojunction structures and have been widely implemented to deal with energy storage. However, they often face general aggregation issues during application. Therefore, to fully exploit the advantages of each material, G and LDHs could be combined to form a novel nanocomposite material. In this review, we summarize the electrochemical energy storage and conversion (EESC) systems based on graphene/LDH (GLDH) composites, including their application in general supercapacitors (SCs), flexible supercapacitors (FSCs), rechargeable batteries, mental air cells, and oxygen evolution reactions (OER). Furthermore, the unresolved issues and possible improvements in GLDH were highlighted.
通讯机构：
[Wang, C ; Wang, C; Zhang, Y ] ;Nanjing Univ, Sch Phys, Natl Lab Solid State Microstruct, Nanjing 210093, Peoples R China.;Changsha Univ Sci & Technol, Sch Phys & Elect Sci, Hunan Prov Key Lab Flexible Elect Mat Genome Engn, Changsha 410114, Peoples R China.;Nanjing Univ, Collaborat Innovat Ctr Adv Microstruct, Nanjing 210093, Peoples R China.
摘要：
Superlattice potentials imposed on graphene can alter its Dirac states, enabling the realization of various quantum phases. We report the experimental observation of a replica Dirac cone at the Brillouin zone center induced by a superlattice in heavily doped graphene with Gd intercalation using angle-resolved photoemission spectroscopy (ARPES). The replica Dirac cone arises from the (root 3x root 3)R30 degrees superlattice formed by the intervalley coupling of two nonequivalent valleys (e.g., the Kekule '-like distortion phase), accompanied by a bandgap opening. According to the findings, the replica Dirac band in Gd-intercalated graphene disappears beyond a critical temperature of 30 K and can be suppressed by potassium adsorption. The modulation of the replica Dirac band is primarily attributable to the residual frozen gas, which can act as a source of intervalley scattering at temperatures below 30 K. Our results highlight the persistence of the hidden Kekule '-like phase within the heavily doped graphene, enriching our current understanding of its replica Dirac Fermions.
通讯机构：
[XiangQian Yu] S;School of Earth and Space Sciences, Peking University, Beijing, China
关键词：
MAGNETOMETER;SATELLITE;equipped
摘要：
The FY-3E meteorological satellite was launched by China on July 5,2021.The orbit of the satellite is sun-sync...展开更多 The FY-3E meteorological satellite was launched by China on July 5,2021.The orbit of the satellite is sun-synchronous with an orbit altitude 836 km and orbit period 102 min.The satellite is equipped with a triaxial anisotropic magnetore-sistance magnetometer to detect ultra-low frequency waves in the magnetosphere.The magnetometer sensor is situated on the satellite truss.It is approximately 1 m away from the satellite body to reduce the effect of spacecraft fields.收起
摘要：
Abstract: To address the problems of low network accuracy, slow speed, and a large number of model parameters in printed circuit board (PCB) defect detection, an improved detection algorithm of PCB surface defects based on YOLOv5 is proposed, named PCB-YOLO, in this paper. Based on the K-means++ algorithm, more suitable anchors for the dataset are obtained, and a small target detection layer is added to make the PCB-YOLO pay attention to more small target information. Swin transformer is embedded into the backbone network, and a united attention mechanism is constructed to reduce the interference between the background and defects in the image, and the analysis ability of the network is improved. Model volume compression is achieved by introducing depth-wise separable convolution. The EIoU loss function is used to optimize the regression process of the prediction frame and detection frame, which enhances the localization ability of small targets. The experimental results show that PCB-YOLO achieves a satisfactory balance between performance and consumption, reaching 95.97% mAP at 92.5 FPS, which is more accurate and faster than many other algorithms for real-time and high-precision detection of product surface defects. Keywords: PCB defect detection; YOLO; united attention mechanism; PCB-YOLO
摘要：
The van der Waals (vdW) heterostructures are a wonderful playground for condensed matter physics, and the recently discovered two-dimensional magnetism renovates this field. In this work, we construct vdW heterostructures composed of p - and d -magnetic layers, namely carbon-terminated SiC(111)/CrBr3 and hydrogenated graphene (HG)/ CrBr3 . By first-principles calculations, strong interlayer magnetic interaction is predicted, as the interlayer exchange energy is up to hundreds of meV, which may originate from the delocalization of magnetic p orbitals in SiC(111) and HG. Moreover, upon transforming the interlayer magnetic order, the electronic structures of the heterostructures vary dramatically, such as the gap can change from 471 to 4 meV. This significant charge-spin coupling can be ascribed to spin-dependent p−d orbital coupling across the vdW interface. The p−d coupling is turned on/off by switching interlayer magnetic order, and shifts the energy level so that it alters the band gaps. Besides, the magnetic anisotropy of heterostructures also shows dependence on interlayer magnetic order. Our findings provide inspiration to design vdW heterostructures whose electronic structures can be effectively controlled by magnetism, which have potential applications in spintronics.
作者机构：
[Song, Yi-Yan; Wu, Xu-Cai; Li, Shu-Zong; Sun, Qingde; Zhang, Wei-Bing] Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha;410114, China;[Song, Yi-Yan; Wu, Xu-Cai; Li, Shu-Zong; Sun, Qingde; Zhang, Wei-Bing] 410114, China
通讯机构：
[Wei-Bing Zhang] H;Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Sciences, Changsha University of Science and Technology , Changsha 410114, People’s Republic of China
