作者机构:
[Fang, Hongyi; Ke, Weijun; Pu, Dexin; Guan, Hongling; Zhou, Shun; Chen, Guoyi; Fang, Guojia; Fu, Shiqiang; Ke, WJ; Jia, Peng; Wang, Chen] Wuhan Univ, Sch Phys & Technol, Key Lab Artificial Micro & Nanostruct, Minist Educ, Wuhan 430072, Peoples R China.;[Jumabaev, Abduvakhid; Hushvaktov, Hakim] Samarkand State Univ, 15 Univ Blvd, Samarkand 140104, Uzbekistan.;[Meng, Weiwei] South China Normal Univ, South China Acad Adv Optoelect, Guangzhou 510006, Peoples R China.;[Wang, Xingzhu; Wang, XZ] Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Peoples R China.;[Wang, Xingzhu; Wang, XZ] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
通讯机构:
[Meng, WW ; Wang, XZ ; Jumabaev, A ] S;[Ke, WJ ] W;Wuhan Univ, Sch Phys & Technol, Key Lab Artificial Micro & Nanostruct, Minist Educ, Wuhan 430072, Peoples R China.;Samarkand State Univ, 15 Univ Blvd, Samarkand 140104, Uzbekistan.;South China Normal Univ, South China Acad Adv Optoelect, Guangzhou 510006, Peoples R China.
关键词:
blade coating;large area;strain;tandem solar cells;wide-bandgap perovskites
摘要:
Blade‐coated wide‐bandgap perovskites encounter top–down inhomogeneity strains. Utilizing mixed‐cation post‐treatment for strain relief, large‐area wide‐bandgap solar cells demonstrate enhanced efficiency and stability. Specifically, 1 cm2‐area 1.77 eV‐bandgap cells achieve an 18.71% efficiency (stabilized at 18.50%), while 4‐terminal all‐perovskite tandems reach an exceptional 27.64% efficiency, coupled with enhanced stability. Abstract The realization of efficient large‐area perovskite solar cells stands as a pivotal milestone for propelling their future commercial viability. However, the upscaling fabrication of perovskite solar cells is hampered by efficiency losses, and the underlying growth mechanism remains enigmatic. Here, it is unveiled that a prevalent upscaling technology, namely blade‐coating, inherently triggers top‐down inhomogeneity strains, predominantly concentrated on the surface of wide‐bandgap perovskite films. Through strain mitigation strategies, the perovskite films exhibit reduced halide vacancies, leading to enhanced stability and improved optoelectronic characteristics. Consequently, the blade‐coated perovskite solar cells achieve minimal efficiency loss when transitioning from small‐area to large‐area devices, enabling the realization of 1 cm2‐area 1.77 eV‐bandgap cells with a remarkable efficiency of 18.71%. Additionally, the strain‐relieved device exhibits an exceptional 109% retention of its initial efficiency even after 400 h of continuous operation, in stark contrast to the control device which experiences a decline to 91%. Furthermore, the resulting 4‐terminal all‐perovskite tandem solar cells crafted utilizing blade‐coated 1.77 eV‐bandgap subcells achieve a maximum efficiency of 27.64% (stabilized at 27.28%). This study not only sheds light on the intricacies of upscaling preparation techniques but also overcomes potential obstacles that can impede the trajectory toward achieving large‐scale perovskite solar cells.
摘要:
The fusion of low-resolution hyperspectral image (LR-HSI) and high-resolution multispectral image (HR-MSI) is a crucial technology for producing high-resolution hyperspectral images. Most existing image fusion algorithms based on deep learning do not fully utilize the ability of neural network to extract and process multi-scale features, which leads to the problem of difficulty in fully learning features and ambiguity of features. In order to overcome these issues, a residual selective kernel attention-based U-net named RSKAU-net is designed for LR-HSI and HR-MSI fusion. RSKAU-net is constructed by a residual selective kernel module with an attention mechanism and a channel attention block. The residual selective kernel attention-based (RSKA) module is designed to process images of different resolutions, which adaptively extracts multi-scale features and efficiently emphasizes significant features through the attention mechanism. The channel attention (CA) module retains important spectral information by assigning different weights to each channel of LR-HSI. The proposed network can enhance the spatial information of LR-HSI while preserving its spectral information. Meanwhile, it effectively fuses the features from the source image to obtain the HR-HSI with rich details. The experimental results demonstrate that the proposed network has advantages in terms of both visual effect and objective quantitative indices when compared to existing HSI-MSI fusion approaches.
摘要:
Metal halide perovskite (MHP) detectors are highly esteemed for their outstanding photoelectric properties and versatility in applications. However, they are unfortunately prone to degradation, which constitutes a significant barrier to their sustained performance. This review meticulously delves into the causes leading to their instability, predominantly attributable to factors such as humidity, temperature, and electric fields and, notably, to various radiation factors such as X-rays, gamma-rays, electron beams, and proton beams. Furthermore, it outlines recent advancements in strategies aimed at mitigating these detrimental effects, emphasizing breakthroughs in composition engineering, heterostructure construction, and encapsulation methodologies. At last, this review underscores the needs for future improvements in theoretical studies, material design, and standard testing protocols. In the pursuit of optimizing the chemical stability of MHP detectors, collaborative efforts are in an imperative need. In this way, broad industrial applications of MHP detectors could be achieved.
摘要:
An improved metallized polyethylene terephthalate (PET) substrate prepared by catechol (CA) and tetraethylenepentamine (TEPA) composites modification with electroless deposition (ELD) copper layer is presented. Through the polymerization of CA with TEPA, amino and imino groups were generated to adsorb the activated particles required for metallization. To achieve the practical application of this method, different catalytic approaches were validated. Under different catalytic conditions, the catalytic effect of UV light was most pronounced, reaching almost four times than that in darkness. The resulting solid copper layers exhibited highly reliable electrical properties, including a low resistivity of 2.73 mu omega cm, tightly spaced crystalline particles and excellent mechanical properties. The fabricated metallized PET substrates were verified for use in flexible circuit boards, demonstrating the compatibility of the proposed CA-TEPA composites modification method with the PET substrates. This method provides an effective approach to the metallization of the PET substrates, which has a widespread application in manufacturing of flexible electronics such as film capacitors.
作者机构:
[Liang, Xianxiao; Zhao, Yang; Shi, Xuan; Shi, X; Deng, Xueyi] Chongqing Univ Posts & Telecommun, Sch Optoelect Engn, Chongqing 400065, Peoples R China.;[Liang, Xianxiao; Zhao, Yang; Shi, Xuan; Shi, X; Xiao, Zeyun; Peng, Xiaoyu; Deng, Xueyi] Chinese Acad Sci, Chongqing Inst Green & Intelligent Technol, Chongqing 400714, Peoples R China.;[Zhao, Hongquan] South China Univ, Sch Elect Engn, Hengyang, Peoples R China.;[Yuan, Hongkuan] Southwest Univ, Sch Phys Sci & Technol, Chongqing, Peoples R China.
通讯机构:
[Yuan, HK ; Zhao, HQ ] S;[Shi, X ] C;Chongqing Univ Posts & Telecommun, Sch Optoelect Engn, Chongqing 400065, Peoples R China.;Chinese Acad Sci, Chongqing Inst Green & Intelligent Technol, Chongqing 400714, Peoples R China.;South China Univ, Sch Elect Engn, Hengyang, Peoples R China.
关键词:
WSe2/Si2H heterojunction;first principles;extra electric field;optical absorption coefficient
摘要:
Van der Waals heterojunctions based on two-dimensional (2D) materials hold great potential applications in photodetectors. Using the density functional theory (DFT) method, the structures, electronic and optical properties of van der Waals WSe2/Si2H heterojunction are investigated. 1.32 eV of indirect bandgap is calculated from the WSe2/Si2H heterojunction, which is 0.3 eV and 0.1 eV smaller than those of its monolayer WSe2 and Si2H. This contributes to the photocarrier generations, and the Type-II heterojunction also benefits to the separation of the photogenerated electron and hole pairs. A significant hole mobility 1.05 x 10(4) cm(2) V-1 s(-1) of the heterojunction along the y-direction is obtained. Moreover, a high Ultraviolet light (UV) absorption coefficient is presented in the heterojunction. The heterojunction transforms to Type-I under a vertical electric field, with the bandgap, orientation and amount of transfer electrons modulated sufficiently. As a result, the optical absorption coefficient of the heterojunction is also improved significantly, leading to the red-shift of the absorption spectrum. These excellent properties address the WSe2/Si2H heterojunction one of the good candidates for UV detectors.
摘要:
Chronic, non-healing wounds pose significant challenges for public health, particularly in the context of diabetes, and carry significant economic consequences. This article introduces a new solution in the form of a wireless theranostic patch, developed to meet the critical need for real-time monitoring and targeted treatments to facilitate optimal healing. The patch incorporates advanced materials that are both multifunctional and electro-responsive, leveraging a sophisticated blend of smart hydrogels and wearable bioelectronics to support diabetic wound management with unparalleled efficacy. With electro-responsive multifunctional polymer hydrogels at its core, the patch delivers a stretchable, antimicrobial, and moist environment for the wound, with added benefits such as conductivity and visibility. The materials also allow for continuous and autonomous monitoring of glucose and pH levels, providing precise and personalized treatments like insulin delivery via iontophoresis and electrical stimulation. Animal models have demonstrated that this integrated system is highly adaptable, effectively promoting wound closure and healing. Overall, the wireless theranostic system offers an exciting prospect for personalized healthcare solutions, adopting a patient-centric approach that prioritizes real-time, targeted care for chronic wounds. Its incorporation of advanced materials and electro-controlled treatments paves the way for new and innovative approaches to wound management. A wireless theranostic wound patch is designed to tackle the critical need by continuous monitoring of glucose and pH, on-demand delivering of insulin via iontophoresis, and electrical stimulation. Moreover, integrating wearable bioelectronics with advanced multifunctional and electro-responsive hydrogels provides a stretchable, antimicrobial, and moist environment for wounds, resulting in high efficacy in diabetic wound management. image
摘要:
An essential industrial application is the examination of surface flaws in hot-rolled steel strips. While automatic visual inspection tools must meet strict real-time performance criteria for inspecting hot-rolled steel strips, their capabilities are constrained by the accuracy and processing speed of the algorithm used to identify defects. To solve the problems of poor detection accuracy, low detection efficiency, and unsuitability of low computing power platforms of the hot-rolled strip surface defect detection algorithm The Swin-Transformer-YOLOv5 model based on the improved one-stage detector is proposed. By employing GhostNet, the model's lightweight design, and guaranteed detection accuracy are both achieved. The C3 module introduces Swin-Transformer to address the issues of cluttered backdrops of defect photos and easily confused defect categories. With the addition of the CoordAttention module, the model's capacity to extract defective features is improved, and its performance keeps getting better. The issue of huge differences in different scales and poor detection of small flaws is resolved by employing BiFPN for feature fusion, and the detector's capacity to adapt to targets of different scales is improved. The experimental results demonstrate that the improved Swin-Transformer-Yolov5 model significantly outperforms the industry-standard target detection algorithms, and the model's mAP value still improves by 8.39% over the original model while reducing the number of parameters, GFLOPs, and weight by 36.6%, 40.0%, and 34.7%, respectively. The model is better suited for use on low-arithmetic platforms as a result.
摘要:
In recent years, frequency-modulated continuous-wave (FMCW) radars have been widely used in the automotive field to measure the relative distance and speed of external targets. To address the problems of poor sensitivity, narrow measurement range, and poor stability of current FMCW radar systems, a high-order all-digital phase-locked loop (ADPLL) based on a fast-integration structure was designed for the FMCW radar. According to the measurement principle of the distance and velocity of objects using radar, the loop structure was designed using integrated circuit chip technology. A Z-domain model of the loop system was built using MATLAB software, and stability analyses and comparisons were performed. The loop program was written using the hardware description language and simulated using the MODELSIM software. Simulation results were combined to verify the accuracy of the hardware design. The experimental results showed that the ADPLL effectively increased the phase-locking frequency, expanded the frequency modulation range by nearly ten times, reduced the system delay by approximately 36%, and improved system stability.
摘要:
The electrocatalytic nitrogen reduction reaction (eNRR) under ambient conditions is a promising alternative to the Haber-Bosch process, but one of the primary pending issues for the eNRR is the development of efficient and stable electrocatalysts. Herein, we propose to prepare a ZIF-67-derived nitrogen-doped porous carbon-supported Co9S8 nanocomposite achieving the maximum average of 9.80 mu g h(-1) mg(cat)(-1) NH3 yield and the highest Faradaic efficiency (FE) of 9.89% in 0.1 M Na2SO4. Moreover, Co9S8/NC shows excellent electrocatalytic stability and durability for the eNRR.
关键词:
Oil and gas pipeline;Risk assessment (RA);Tangible risk;Intangible risk;Probability calculation;Reputation loss
摘要:
Oil and gas pipeline accidents not only caused personnel casualties, economic losses and environmental pollution but also brought great panic to the public. To provide accurate accident prevention strategies, risk assessment (RA) has been widely used in the oil and gas pipeline industry. It aims to quantify the potential risk due to unexpected eventualities. However, the current RA methods mainly pay attention to the tangible risk (such as the human safety risk, economic risk and environmental risk), and the intangible risk (such as reputation loss risk) is often neglected. This cannot reflect the real risk for the oil and gas pipeline. To settle existing research limitation, a two-dimensional risk assessment method for oil and gas pipelines based on “accident probability–reputation loss” is proposed. The method mainly involves four steps, namely, risk identification, probability calculation, consequence assessment and risk assessment. The proposed method is used to quantitatively assess a natural gas pipeline in central China. Its results indicate that pipeline risk is unacceptable due to the unacceptability of accident probability and various dimensions of risk. Therefore, this study can enrich and develop the current oil and gas pipeline RA method to reflect the real risk of oil and gas pipeline accidents.
通讯机构:
[Li, YH ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
关键词:
Pixel circuit;LTPS TFTs;Threshold voltage variation;Mobility variation;Voltage drop;OLED degradation
摘要:
A voltage-programmed pixel circuit based on low-temperature poly-silicon (LTPS) thin-film transistors (TFTs) is presented for active-matrix organic light-emitting diode (AMOLED) displays. The circuit consists of six ptype transistors and one capacitor (6T1C). During the extraction stage, the circuit extracts the driving TFT's threshold voltage and the power supply voltage. During the data input stage, the circuit generates a charging voltage, which is associated with the driving TFT's mobility and the OLED's threshold voltage. Consequently, the pixel circuit, using only one capacitor, compensates not only for the TFT's electrical characteristics variations, i.e., the threshold voltage variation and mobility variation, but also for the power supply voltage drop and the OLED degradation. The circuit simulation results reveal that the OLED current error rates (CERs) are lower than 5.09% when the threshold voltage varies by +/- 0.5 V, lower than 3.61% when the mobility varies by +/- 30%, and lower than 9.16% when the voltage drop varies by -0.5 V in the data voltage range.
摘要:
The study of rare-earth (RE) doping in two-dimensional (2D) transition metal dichalcogenides (TMDCs) has become an important research focus to modulate bandgaps and carriers for production of the exotic properties. Herein, approximately 7 at% of Yb substitutionally doped monolayer WS2 nanosheets are prepared by in-situ chemical vapor deposition (CVD) technique. Highly enhanced optical and electrical properties are obtained: Three times enhancement in photoluminescent intensities and 5.6 nm of red-shifts in wavelength are observed from their peaks after chemical doping. First-principles calculations based on density functional theory (DFT) demonstrate a shrinked bandgap of Yb-doped monolayer WS2 at K-point in Brillouin zone compared with that of the pristine WS2 monolayer, and a broadened absorption and reflectivity spectra from visible to near-infrared region, which is in good agreement with the experimental results. Photodetectors based on Yb-doped monolayer WS2 nanosheets show far higher of mobility (17 times), photocurrent, photoresponsivity, and external quantum efficiency than those of the pristine WS2. The results prove a high effectiveness of RE doping in 2D materials for high-performance optoelectronic devices.
通讯机构:
[Wang, XZ ; Du, XY; Hao, XT ] S;Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.;Southern Univ Sci & Technol, Acad Adv Interdisciplinary Studies, Shenzhen 518055, Guangdong, Peoples R China.;Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Guangdong, Peoples R China.;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
关键词:
exciton dynamics;non-fullerene acceptors;organic solar cells;photovoltaic stability;ultrafast spectroscopy
摘要:
Benefiting from the synergistic development of material design, device engineering, and the mechanistic understanding of device physics, the certified power conversion efficiencies (PCEs) of single-junction non-fullerene organic solar cells (OSCs) have already reached a very high value of exceeding 19%. However, in addition to PCEs, the poor stability is now a challenging obstacle for commercial applications of organic photovoltaics (OPVs). Herein, recent progress made in exploring operational mechanisms, anomalous photoelectric behaviors, and improving long-term stability in non-fullerene OSCs are highlighted from a novel and previously largely undiscussed perspective of engineering exciton and charge carrier pathways. Considering the intrinsic connection among multiple temporal-scale photocarrier dynamics, multi-length scale morphologies, and photovoltaic performance in OPVs, this review delineates and establishes a comprehensive and in-depth property-function relationship for evaluating the actual device stability. Moreover, this review has also provided some valuable photophysical insights into employing the advanced characterization techniques such as transient absorption spectroscopy and time-resolved fluorescence imagings. Finally, some of the remaining major challenges related to this topic are proposed toward the further advances of enhancing long-term operational stability in non-fullerene OSCs.
摘要:
High concentration of Er3+/Yb3+ co‐doped WS2 monolayer is creatively prepared by in‐situ chemical vapor deposition technique. The performances of the devices (photodetectors and field‐effect transistors) are significantly enhanced after rare‐earth (RE) co‐doping, which can be attributed to the stronger light absorption and higher the transitions of electronic states, providing an excellent strategy for practical application in optoelectronics. Abstract Chemical doping is a significant means to modulate bandgap structures and optoelectronic properties of transition metal dichalcogenides (TMDCs). Herein, an Er3+/Yb3+ co‐doped WS2 monolayer with ultrahigh and tunable concentrations is successfully fabricated by in‐situ chemical vapor deposition (CVD) technique. The morphologies, thicknesses, components, and structures of the samples are systemically characterized by optical microscope, atomic force microscopy, Raman, X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscope with energy dispersive spectrometer, and high‐resolution transmission electron microscopy, respectively. Photoluminescent peaks are enhanced significantly with red shifts, and the absorption is broadened to near‐infrared, implying a shrinked bandgap after RE co‐doping, which is consistent to the calculation results by density functional theory (DFT). The Er3+/Yb3+ co‐doped WS2 device demonstrates high carrier mobility, photocurrent, photoresponsivity, external quantum efficiency, and specific detectivity, which are approximately two orders of magnitudes compared with those of the pristine WS2 device. The values of photoresponsivity and specific detectivity approach 4.8 × 104 A W−1 and 5.5 × 1014 Jones, respectively, at 20 V bias and 1.77 mW cm−2 luminescence, which may refresh the records as has been reported. The excellent performances of the WS2 photodetector prove the effectiveness of Er3+/Yb3+ co‐doping for practical application in optoelectronics.
摘要:
The electrocatalytic nitrogen reduction reaction (eNRR) under ambient conditions is deemed a promising alternative for NH(3) synthesis. In this paper, an FeP-Fe(3)O(4) nanocomposite electrocatalyst was prepared by phosphating annealing using Fe(2)O(3) as a precursor, and the resulting FeP-Fe(3)O(4) exhibited excellent N(2)-to-NH(3)-producing activity over a wide potential window. The highest faradaic efficiency of FeP-Fe(3)O(4) is 11.02% at -0.1 V vs. reversible hydrogen electrode (RHE), and the maximum NH(3) yield reaches 12.73 μg h(-1) mg(cat)(-1), comparable to or exceeding the reported values in this field. Furthermore, the FeP-Fe(3)O(4) nanocomposite electrocatalyst presents high electrochemical stability, selectivity, and durability.
作者机构:
[Wen, Juan; Xiao, Qiankang; Qu, Xing; Lin, Siyu] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;[Liu, Jie] Univ South China, Sch Comp Software, Hengyang 421001, Peoples R China.
通讯机构:
[Wen, J ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
关键词:
Active distribution network;Fault location;Dynamic quantum genetic algorithm;Evaluation objective function
摘要:
The fault location of an active distribution network is a vital analysis to prevent major outages in the power system. Considering the influence of renewable distributed generations on fault characteristics, this paper proposes a novel location method based on a dynamic quantum genetic algorithm to solve for fault locations in active distribution networks. In the method, the fault current code is measured based on feeder terminal units. A universal switching function is presented to convert the feeder switch status into an uploaded fault current code. The fault location model is defined as an optimization problem that presents the evaluation objective function with an anti-false-positive factor. The dynamic quantum genetic algorithm is developed to locate the fault feeder according to the uploaded fault current code of the feeder terminal unit. The algorithm adopts dynamic rotating gate strategy and adaptive quantum crossover strategy to satisfy the requirements of quickness and accuracy for fault location. Moreover, the method avoids easily falling into a local optimum by integrating the discrete quantum mutation. The proposed fault location technique is tested and compared to other existing techniques on a 33-bus active distribution network. The simulation results show that the proposed fault location method can locate fault feeders accurately with fast computational times under conditions of single or multiple faults and with an information distortion of the feeder terminal unit.
期刊:
Biomedical Signal Processing and Control,2024年87:105458 ISSN:1746-8094
通讯作者:
Zhang, XZ;Xiong, DP
作者机构:
[Zhang, XZ; Zhang, Xiaozhi; Zhang, Xichu] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;[Ouyang, Lijun; Xiong, Dongping; Xiong, DP] Univ South China, Sch Comp Software, Hengyang 421001, Peoples R China.;[Qin, Chuanbo] Wuyi Univ, Fac Intelligent Mfg, Jiangmen 529020, Peoples R China.;[Xiao, Lin] Jiangmen Cent Hosp, Radiotherapy Ctr, Jiangmen 529020, Peoples R China.
通讯机构:
[Zhang, XZ ; Xiong, DP ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;Univ South China, Sch Comp Software, Hengyang 421001, Peoples R China.
关键词:
Medical image segmentation;Sparse attention;Deep supervision;Transformer
摘要:
Medical image segmentation aims at recognizing the object of interest from surrounding tissues and structures, which is essential for the reliable diagnosis and morphological analysis of specific lesions. Automatic medical image segmentation has been significantly boosted by deep Convolutional Neural Networks (CNNs). However, CNNs usually fail to model long-range interactions due to the intrinsic locality of convolutional operations, which limits the segmentation performance. Recently, Transformer has been successfully applied in various computer visions, which leverages the self-attention mechanism for modelling long-range interactions to capture global information. Nevertheless, self-attention suffers from lacks of spatial locality and efficient computation. To address these issues, in this work, we develop a new sparse medical Transformer (SMTF) with multiscale contextual fusion for medical image segmentation. The proposed model combines convolutional operations and attention mechanisms to form a U-shaped framework to capture both local and global information. Specifically, to reduce the computational cost of traditional Transformer, we design a novel sparse attention module to construct Transformer layers by spherical Locality Sensitive Hashing method. The sparse attention partitions the feature space into different attention buckets, and the attention calculation is conducted only in the individual bucket. The designed sparse Transformer layer further incorporates a bottleneck block to construct the encoder in SMTF. It is worth noting that the proposed sparse Transformer can also aggregate the global feature information in early stages, which enables the model to learn more local and global information by incorporating CNNs at lower layers. Furthermore, we introduce a deep supervision strategy to guide the model to fuse multiscale feature information. It further enables the SMTF to effectively propagate feature information across layers to preserve more input spatial information and mitigate information attenuation. Benefiting from these, it can achieve better segmentation performance while being more robust and efficient. The proposed SMTF is evaluated on multiple medical image segmentation datasets and a clinical nasopharyngeal carcinoma dataset. Extensive experiments have demonstrated its superiority on both qualitative and quantitative evaluations. Code and models are available at https://github.com/qmx717/sparse-attention.git .
期刊:
Measurement Science And Technology,2023年34(7) ISSN:0957-0233
作者机构:
[Bi, Zhicheng] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.;[Liu, Zhenghai; Yang, Xiaohua; Gao, Yu; Wang, Chaofeng; Wan, Yaping] Univ South China, Sch Comp Sci, Hengyang 421001, Peoples R China.
关键词:
millimeter-wave radar;radar point cloud;target detection;spatial-temporal clustering
摘要:
Millimeter-wave (mmWave) radar plays a vital role in a wide range of applications such as security surveillance and environmental monitoring. This work investigates target detection with radar point cloud measurements in the slow-motion scenario. In contrast to the existing spatial domain clustering-based target detection methods, we adopt a recursive spatial-temporal clustering (STC)-based method to detect targets in the spatial and temporal domain jointly. Specifically, the points belonging to targets are obtained by clustering with a distance metric defined in the spatial-temporal domains. In addition, to ensure the feasibility of the proposed method for practical real-time implementation, a speed-up scheme that intends to reduce the computational complexity induced by clustering in both spatial and temporal dimensions is developed. We demonstrate the efficacy of the proposed recursive STC-based method through experimental mmWave radar point cloud data where multiple people walk simultaneously in an open space. The proposed method achieves decent target detection performance improvement compared to a widely-used clustering method for target detection while its computation time is negligible compared to radar data reception time.
摘要:
The visible (VS) and near-infrared (NIR) image fusion is a common approach to improve image visibility, which saves rich scene details and similar colors to the VS image in fused image. However, preserving edge details and preventing color distortion is a fundamental yet challenging problem for VS-NIR fusion work. To address this problem, this article proposes a novel image fusion method based on multiscale gradient guided edge-smoothing (MGES) model and local gradient weight. According to the spectrum characteristics of VS and NIR, the local gradient weight is established by analyzing the local gradient difference of VS and NIR, aiming to only transfer the prominent details of NIR image to VS image, thereby avoiding the confusion of spectral information. Furthermore, the MGES model is designed to simultaneously generate a Laplacian pyramid and a gradient domain guided filtering-based weight pyramid, which fully considers the gradient correlation between neighboring pixels and omits the Gaussian filtering step, thus effectively preserving spatial details and suppressing halo artifacts. Subjective and objective experimental results demonstrate the superiority of the proposed method over state-of-the-art methods in terms of preserving edge details and maintaining color naturalness. [GRAPHICS]
作者机构:
[Gong, Yujie; Sheng, Yifa; Liu, Jun; Wang, Qiyou] Univ South China, Sch Elect Engn, Hengyang 421001, Hunan, Peoples R China.;[Tan, Yao; Zi, Xin; Liu, Min; Luo, Tao; Wang, Qiyou; Cai, Chao; Liu, M; Li, Hongmei; Liu, Kang; Fu, Junwei] Cent South Univ, Sch Phys, Hunan Joint Int Res Ctr Carbon Dioxide Resource Ut, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.;[Abazari, Reza] Univ Maragheh, Dept Chem, POB 55181-83111, Maragheh, Iran.;[Li, Wenzhang; Chen, Shanyong] Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Zhang, Shiguo] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.
通讯机构:
[Liu, M ] C;[Liu, J ] U;Univ South China, Sch Elect Engn, Hengyang 421001, Hunan, Peoples R China.;Cent South Univ, Sch Phys, Hunan Joint Int Res Ctr Carbon Dioxide Resource Ut, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词:
Alkaline hydrogen evolution;Local electric field;Electron localization;Cu doping;CoS 2 nanoneedles
摘要:
Alkaline hydrogen evolution reaction (HER) represents a promising means to store intermittent renewable energy into clean energy. Unfortunately, the sluggish H2O dissociation and difficult *H adsorption-desorption are prominent obstacles to the development of alkaline HER. Herein, we developed a cooperative strategy via nanoneedle inducing local electric field and atomic doping causing electron localization for alkaline HER based on the preparation of Cu doped CoS2 nanoneedles (Cu-CoS2 NNs). Finite element method simulations and density functional theorycalculations demonstrate the local electric field accelerates H2O dissociation and electron localization facilitates *H adsorption, respectively. In situ attenuated total reflection infrared spectroscopy and electro-response measurement experimentally reveal the superior ability to H2O dissociation and *H adsorption for Cu-CoS2 NNs. As a result, the Cu-CoS2 NNs exhibit an ultralow overpotential of 64 mV at -10 mA cm-2 and long-term stability over 100 h at -100 mA cm-2 during alkaline HER, which outperforms most electrocatalysts in recently published works. Published by Elsevier B.V. All rights reserved.