- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Photovoltaic Properties and Series Resistance of <i>p</i> -Type Si/Intrinsic Si/ <i>n</i> -Type Nanocrystalline FeSi <sub/>2</sub> Heterojunctions Created by Utilizing Facing-Targets Direct-Current Sputtering
摘要： p-Type Si/intrinsic Si/n-type nanocrystalline iron disilicide heterojunctions were created by utilizing facing targets direct-current sputtering at the pressure of 1.33 × 10?1 Pa that investigated the photovoltaic properties. They exhibited a large leakage current and a small energy conversion ef?ciency of 0.62%. From using the method of Nicollian and Brews, the series resistance (Rs) values at zero bias voltage were 7.40 Ω at 2 MHz and 7.57 Ω at 50 kHz, respectively, which were in agreement with that estimated by the means of Norde. From applying the method of Hill-Coleman, the interface state density (Nss) values were 3.15 × 1015 cm?2 eV?1 at 50 kHz and 8.93 × 1013 cm?2 eV?1 at 2 MHz. The obtained results revealed the presence of Rs and Nss at the junction interface, which should be the potential cause of spoiled photovoltaic performance in the heterojunctions.
关键词： Heterojunctions,Facing-Targets Direct-Current Sputtering,Nanocrystalline Iron Disilicide,Series Resistance,Interface State Density
更新于2025-11-14 17:28:48
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Ship detection in spaceborne infrared images based on Convolutional Neural Networks and synthetic targets
摘要： Automatic detection of ships in spaceborne infrared images is important for both military and civil applications due to its all-weather detection capability. While deep learning methods have made great success in many image processing fields recently, training deep learning models still relies on large amount of labeled data, which may limit its application performance for infrared images target detection tasks. Considering that, we propose a new infrared ship detection method based on Convolutional Neural Networks (CNN) which is trained only with synthetic targets. For the problem of limited infrared training data, we design a Transfer Network (T-Net) to generate large amount of synthetic infrared-style ship targets from Google Earth images. The experiments are conducted on a near infrared band image (0:845μm s 0:885μm), a short wavelength infrared band image (1:560μm s 1:66μm) and a long wavelength infrared band image (2:1μm s 2:3μm) of Landsat-8 satellite. The results demonstrate the effectiveness of the target generation ability of T-Net. With only synthetic training samples, our detection method achieves a higher accuracy than other classical ship detection methods.
关键词： Convolutional Neural Networks,Spaceborne infrared image,Synthetic targets,Ship detection
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - Qingdao, China (2018.9.14-2018.9.16)] 2018 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC) - A Real-time Detection Algorithm for Unmanned Aerial Vehicle Target in Infrared Search System
摘要： Aiming at the difficulty of infrared target detection of 'low and slow small' unmanned aerial vehicles (UAV) in complex low-altitude background, this paper proposes a new target detection algorithm based on multiscale fusion filtering. Combined with spatial multiscale decomposition filtering and temporal multiscale difference processing, the algorithm can effectively overcome many difficulties such as complex low-altitude background interference, unknown target scale, unknown angular velocity and low target signal-to-noise ratio (SNR). The test result shows that the algorithm can effectively detect the UAV targets with different distances in complex low-altitude background, and the false alarm rate is low. The algorithm is realized in TI 6657 DSP and realizes 100Hz real-time processing of mid-wave infrared images with 640*512 resolution, which has been effectively applied to the large-field circumferential scanning infrared search system developed by ATR Lab.
关键词： real-time algorithm,multiscale fusion filtering,UAV target detection,low-altitude background,low and slow small targets
更新于2025-09-23 15:23:52
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Multi-target joint detection, tracking and classification based on random finite set for aerospace applications
摘要： Multi-target detection, tracking and classification are important problems in aerospace applications, such as reconnaissance, airborne and spaceborne sensing. These problems are correlated but are difficult to be solved simultaneously, especially for systems with multiple sensors. This paper summarized the existing work for multi-target joint detection, tracking and classification based on labeled random finite set. Furthermore, a new algorithm is proposed for multi-sensor multi-target joint detection, tracking and classification problem. A conditional multi-sensor multi-target state estimator is derived, and the optimal solution is then obtained based on the minimum Bayes risk criterion. The numerical simulations are performed, and the results are shown to be more accurate than that of the approximate solutions based on the unlabeled random finite set. It is observed that the labeled random finite set theory provides a good foundation for a joint solution for multi-target detection, tracking and classification.
关键词： Multiple targets,Tracking and classification,Labeled RFS,Generalized bayesian risk,Sensor registration,Joint detection
更新于2025-09-23 15:23:52
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UTILIZA??O DE ALVOS CODIFICADOS DO TIPO ARUCO NA AUTOMA??O DO PROCESSO DE CALIBRA??O DE C?MARAS
摘要： This paper presents a proposal for the automation of the camera calibration process, locating and measuring image points in coded targets with sub-pixel precision. This automatic technique helps minimize localization errors, regardless of camera orientation and image scale. To develop this technique, several types of coded targets were analyzed and the ARUCO type was chosen due to its simplicity, ability to represent up to 1024 different targets and availability of source code implemented with the OpenCV library. ARUCO targets were generated and two calibration sheets were assembled to be used for the acquisition of images for camera calibration. The developed software can locate targets in the acquired images and it automatically extracts the coordinates of the four corners with sub-pixel accuracy. Experiments were conducted with real data showing that the targets are correctly identified unless excessive noise or fragmentation occurs mainly in the outer target square. The results with the calibration of a low cost camera showed that the process works and that the measurement accuracy of the corners achieves sub-pixel precision.
关键词： Calibration Chambers,Targets Coded,Photogrammetry,ARUCO,OpenCV,Sub-Pixel
更新于2025-09-23 15:22:29
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Identification of Protein Targets of Bioactive Small Molecules Using Randomly Photomodified Probes
摘要： Identifying protein targets of bioactive small molecules often requires complex, lengthy development of affinity probes. We present a method for stochastic modification of small molecules of interest with a photoactivatable phenyldiazirine linker. The resulting isomeric mixture is conjugated to a hydrophilic copolymer decorated with biotin and a fluorophore. We validated this approach using known inhibitors of several medicinally relevant enzymes. At least a portion of the stochastic derivatives retained their binding to the target, enabling target visualization, isolation, and identification. Moreover, the mix of stochastic probes could be separated into fractions and tested for binding affinity. The structure of the active probe could be determined and the probe re-synthesized to improve binding efficiency. Our approach can thus enable rapid target isolation, identification, and visualization, while providing information required for subsequent synthesis of an optimized probe.
关键词： bioactive small molecules,target isolation,protein targets,target identification,stochastic modification,target visualization,photoactivatable phenyldiazirine linker,biotin,fluorophore,hydrophilic copolymer
更新于2025-09-23 15:21:21
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Enhancement of dim targets in a sea background based on long-wave infrared polarisation features
摘要： According to Fresnel's formula and the energy conservation law, a model combining the infrared reflected effect and emitted effect is developed to calculate the polarisation degree. With this model, the polarisation degree difference between the sea surface and ship target in long-wave infrared is simulated. To solve the problem of dim targets detection in a sea background, based on the polarisation difference of the sea surface and ship targets, a method of the non-subsampled shearlets transformation is proposed to fuse the intensity image and polarisation image. The algorithm of distribution coefficients is applied to improve the contrast ratio between targets to background in low-frequency subbands. The denoise scheme of the adaptive threshold is adopted to suppress noise and the conceptions of local direction contrast and region gradient are used as a choosing scheme to the preserve features and edges of images in high-frequency subbands. Image evaluation indices of target contrast with the background and local signal-to-noise ratio are used to evaluate the enhancement effect of fused images. Results show that the evaluation indices of fused images with polarisation features are significantly improved, and comparisons with existing methods demonstrate the effectiveness and reliability of the proposed method.
关键词： infrared polarisation,image fusion,sea background,dim targets,non-subsampled shearlets transformation
更新于2025-09-23 15:21:21
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Numerical simulations on laser absorption enhancement in hybrid metallo-dielectric nanostructured targets for future nuclear astrophysics experiments
摘要： The linear electromagnetic interaction between innovative hybrid metallo-dielectric nanostructured targets and laser in visible and IR range is investigated through numerical simulations. The obtained results rely on the optimization of a target based on metallic nanowires (NWs) to enhance light absorption in the visible range of the electromagnetic spectrum. The NWs are grown within the ordered nanoholes of an alumina substrate, thus, forming a plasmonic lattice with triangular symmetry. The remaining volume of the nanoholes on top of the NWs is sealed with a transparent layer of aluminum oxide that is suitable to be chemically modified for containing about 25% of deuterium atoms. The study presented here is carried out within the framework of a scientific program named PLANETA (Plasmonic Laser Absorption on Nano-Engineered Targets) aiming at investigating new laser–matter interaction schemes in the ns domain and for nuclear fusion purposes, involving especially the D–D reaction.
关键词： D–D reaction,metallo-dielectric nanostructured targets,nuclear astrophysics,laser absorption,plasmonic lattice
更新于2025-09-23 15:21:01
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Bacteria-Targeted Supramolecular Photosensitizer Delivery Vehicles for Photodynamic Ablation Against Biofilms
摘要： Photodynamic therapy (PDT) is believed to be a potent method for biofilm treatments. However, undesired damage to normal cells may be caused due to the nonselective nature of PDT. Therefore, targeted PDT is preferred on one hand to enhance antimicrobial effects and on the other hand to reduce cytotoxicity to normal cells. For this purpose, novel bacteria-targeted photosensitizer delivery micelles are fabricated, taking advantage of α-cyclodextrin (α-CD)/polyethylene glycol (PEG) supramolecular assembly. Hydrophilic antimicrobial peptide (AMP) Magainin I is covalently bound with PEG, working as a bacterial targeting group as well as the stabilizing shell of the supramolecular micelles. Photosensitizer Chlorin e6 (Ce6) is grafted onto α-CD. The micelles exhibit excellent bacterial targeting effects. Compared to α-CD-Ce6, the supramolecular micelles possess enhanced biofilm killing ability against Gram (?) Pseudomonas aeruginosa biofilms and Gram (+) methicillin-resistant Staphylococcus aureus (MRSA) biofilms while reducing cytotoxicity to NIH/3T3 model cells.
关键词： antimicrobial peptides,biofilms,targets,cytocompatibility,photodynamic therapy
更新于2025-09-23 15:21:01
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Effect of fast electrons on the gain of a direct-drive laser fusion target
摘要： The results of numerical and theoretical studies of the gain of a direct-drive inertial con?nement fusion target, which includes a kinetic description of energy transfer by laser-accelerated fast electrons, are presented. The range of the initial temperature of the fast electrons and the fraction of laser energy contained in these particles were chosen based on the results of recent experiments at the National Ignition Facility. The effect of ‘wandering’ of fast electrons is taken into account which is due to the remoteness of the region of fast electron generation from the ablation surface of the imploded target. As a result a signi?cant fraction of particles do not fall into the compressed part of target. The ‘wandering’ effect leads to a decrease in the negative effect of fast electron generation on the gain of the target.
关键词： implosion,energy transfer,fast electrons,direct-drive targets,inertial con?nement fusion
更新于2025-09-23 15:19:57