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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - A New Model for P-Band Pol-InSAR Based on Gamma Distribution
摘要： This work proposes a forest model based on Gamma distribution to better describe the forest vertical structure for height inversion using P-band polarimetric synthetic aperture radar interferometry (Pol-InSAR) data. The proposed model takes into account the forest vertical heterogeneity and asymmetry, to which volume interferometric coherence is sensitive. The interferometric coherence associated with a volume where the vertical backscattered power varies following a Gamma distribution is derived. The effect of scattering center height standard deviation and mean elevation to the volume interferometric coherence is investigated. Finally, the strategy of multi-baseline on the proposed model for forest height inversion using P-band Pol-InSAR data is proposed.
关键词： P-band Pol-InSAR,forest model,Gamma distribution,vertical heterogeneity
更新于2025-09-23 15:22:29
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - Design of Compact Ka Band Antenna System for an InSAR Demonstrator
摘要： a compact and low profile Ka band antenna system designed for a demonstrator in InSAR application is presented in this paper. The system mainly contains 3 modules: the antenna array, the Rx component and the calibration network. The cross-track antenna contains 2 panel arrays and each has a dimension of 454×49.8mm2, while the along-track antenna contains 8 panel arrays and each has a dimension of 227.4×22.4mm2. All the arrays are fixed beam antennas and each will be connected with an Rx component to form a total of 10 active channels. The antennas adopt narrow side waveguide slot antenna as radiating element, and each panel array are composed by a number of smaller linear antenna sub-arrays whose sizes are optimized to have a high realized gains. The connection between antenna array and Rx component is realized by waveguide directly instead of using lossy SMP connector, and the Rx component can be attached at the back of the panel array tightly to improve the integration. The inner calibration network is integrated at the back of the antenna together with its feed network. The whole system as a demonstrator has a compact structure and can be expanded large scale system to meet the urgent conveniently to requirements of high performance antenna system in future InSAR application.
关键词： Ka band,InSAR,antenna system,multi-channel
更新于2025-09-23 15:22:29
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12- and 21-GHz Dual-band Dual-circularly Polarized Offset Parabolic Reflector Antenna Fed by Microstrip Antenna Arrays for Satellite Broadcasting Reception
摘要： In December 2018, satellite broadcasting for 4K/8K ultra-high-definition television (UHDTV) will begin in Japan. It will be provided in the 12-GHz (11.7 to 12.75 GHz) band with right- and left-hand circular polarizations. BSAT-4a, a satellite used for broadcasting UHDTV, was successfully launched in September 2017. This satellite has not only 12-GHz-band right- and left-hand circular polarization transponders but also a 21-GHz-band experimental transponder. The 21-GHz (21.4 to 22.0 GHz) band has been allocated as the downlink for broadcasting satellite service in ITU-R Regions 1 (Europe, Africa) and 3 (Asia Pacific). To receive services provided over these two frequency bands and with dual-polarization, we implement and evaluated a dual-band and dual-circularly polarized parabolic reflector antenna fed by 12- and 21-GHz-band microstrip antenna arrays with a multilayer structure. The antenna is used to receive 12- and 21-GHz-band signals from in-orbit satellites. The measured and experimental results prove that the proposed antenna performs as a dual-polarized antenna in those two frequency bands and has sufficient performance to receive satellite broadcasts.
关键词： microstrip antenna,dual band antenna,circular polarization,reflector antenna,dual polarized antenna
更新于2025-09-23 15:22:29
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High-Resolution ENT Video Endoscope with Superior Image Quality Equivalent to that of Gastric Video Endoscopes
摘要： Background and study aims: To assess the usability of high resolution fiberscope which has equivalent image quality to that of the esophageal and gastric video endoscopes. Patients and methods: Image resolution of this endoscope was estimated by the United States Air Force (USAF) resolution test chart. Clinical application was done between January and December 2010 and transnasal observation of the larynx and hypopharynx were performed during this period. These examinations were done for screening and follow-up for patients with hypopharyngeal and laryngeal disorders. Results: This endoscope could distinguish features on a scale of nearly 20 μm, and abnormal vascular patterns on the mucosal surface characteristic of carcinomas were clearly observed under a conventional light source. In addition, these changes on the mucosal surface became more apparent with use of the i-SCAN?. Nevertheless, the handling of this video endoscope was similar to that of popular ENT video endoscopes, and all patients tolerated its use well. Conclusion: This new device may dramatically improve pharyngolaryngeal examination in ENT clinics.
关键词： Narrow-band imaging,Intraepithelial papillary capillary loops,Early diagnosis,Video endoscope
更新于2025-09-23 15:22:29
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Modeling of circular fractal antenna using BFO-PSO-based selective ANN ensemble
摘要： Accurate design of miniaturized antenna is constrained by the limited well‐formulated exact mathematical expressions. Demands for smart devices with features like portability, implantability, and configurability have further placed bigger challenges in front of the antenna design engineers or scientists. As a part of the search for various solutions, many innovative approaches have been proposed by various authors in different literatures. Application of soft computing is also another design approach to accurate design of fractal antenna. Here, the authors have attempted to propose a better solution to miniaturized antenna and its design. A fractal antenna based on circular outer geometry has been proposed as a solution to the search of miniaturized antennas, and a particle swarm optimization–based selective artificial neural networks ensemble is developed, which is employed as the objective function of a bacterial foraging optimization algorithm leading to a hybridized algorithm. The developed hybrid algorithm is utilized to develop the proposed antenna at 2.45 GHz. A good agreement of the simulated, desired, and experimental results validates the proposed design approach.
关键词： BFO,ANN ensemble,ISM band,fractal antenna,PSO
更新于2025-09-23 15:22:29
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Unique 1D Cd <sub/>1?</sub><i> <sub/>x</sub></i> Zn <i> <sub/>x</sub></i> S@O-MoS <sub/>2</sub> /NiO <i> <sub/>x</sub></i> Nanohybrids: Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Evolution via Integrated Structural Regulation
摘要： Development of noble-metal-free photocatalysts for highly efficient sunlight-driven water splitting is of great interest. Nevertheless, for the photocatalytic H2 evolution reaction (HER), the integrated regulation study on morphology, electronic band structures, and surface active sites of catalyst is still minimal up to now. Herein, well-defined 1D Cd1?xZnxS@O-MoS2/NiOx hybrid nanostructures with enhanced activity and stability for photocatalytic HER are prepared. Interestingly, the band alignments, exposure of active sites, and interfacial charge separation of Cd1?xZnxS@O-MoS2/NiOx are optimized by tuning the Zn-doping content as well as the growth of defect-rich O-MoS2 layer and NiOx nanoparticles, which endow the hybrids with excellent HER performances. Specifically, the visible-light-driven (>420 nm) HER activity of Cd1?xZnxS@O-MoS2/NiOx with 15% Zn-doping and 0.2 wt% O-MoS2 (CZ0.15S-0.2M-NiOx) in lactic acid solution (66.08 mmol h?1 g?1) is about 25 times that of Pt loaded CZ0.15S, which is further increased to 223.17 mmol h?1 g?1 when using Na2S/Na2SO3 as the sacrificial agent. Meanwhile, in Na2S/Na2SO3 solution, the CZ0.15S-0.2M-NiOx sample demonstrates an apparent quantum yield of 64.1% at 420 nm and a good stability for HER under long-time illumination. The results presented in this work can be valuable inspirations for the exploitation of advanced materials for energy-related applications.
关键词： charge separation,1D hybrid nanostructures,photocatalytic hydrogen evolution,band alignments,active sites
更新于2025-09-23 15:22:29
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AIP Conference Proceedings [AIP Publishing LLC NANOFORUM 2014 - Rome, Italy (22–25 September 2014)] - Structural and optical properties of Sn1-xMnxO2 thin films
摘要： Sn1-xMnxO2 thin films are deposited by spray pyrolysis method. XRD of all the thin films show the amorphous nature. Synthesis of SnO2 is also confirmed by FTIR spectroscopy. Undoped SnO2 thin film is 60-70 % transparent in visible and near IR region and it increases up to80-90% for 20 at. % Mn doped SnO2 thin film. The optical band gap is tunable linearly between 3.34 to 3.96 eV for 0≤x≤0.20 for Sn1-xMnxO2 amorphous thin films.
关键词： and FTIR,Thin Films,Band Gap,Optical Transmission
更新于2025-09-23 15:22:29
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Band bending analysis of charge characteristics at GeO <sub/>2</sub> /Ge interface by x-ray photoemission spectroscopy
摘要： Ge complementary metal oxide semiconductor (CMOS) is promising for scaling beyond the Si CMOS due to its higher carrier mobility than Si. Analogue to classical SiO2/Si system in the Si CMOS technology, various interface/bulk charges including interface traps (Qit), fixed surface state charges (Qf), trapped positive charges (Qpt) and negative charges ((Qnt) in GeO2/Ge system are also crucial both for the device performance and reliability. Because small amounts of charges would cause photoemission peak shift characterized by x-ray photoemission spectroscopy (XPS), it offers a feasible way to evaluate various charge densities by measuring the band bending in Ge substrate from Ge 3d core-level energy shift at GeO2/Ge interface. Moreover, photoemission peak shifts as a function of x-ray irradiation time have been widely accepted for characterization of charge trapping phenomena. Here, we report a band bending analysis at GeO2/Ge interface of featuring vital charge characteristics for diverse device applications by XPS. HF-last cleaned Ge surface was verified to tend to be p-type, irrespective of the bulk conductivity. The n-Ge/GeO2 interfaces exhibit a reduction of upward band bending evolution of Ge substrate, while p-type-Ge/GeO2 interfaces indicate a reduction of downward band bending evolution when comparing the different quality GeO2/Ge interfaces. Based on the requirement of surface charge neutrality, such observation has been attributed to a dominated passivation effect to negatively charged interface traps and the positive fixed surface state charges, respectively. Moreover, a time evolution of Ge 3d and O 1s signals reveals a progressive band bending modification at GeO2/Ge interface, clarifying the thermally-grown GeO2 also contains electron traps (Qnt). Ultimately, the four types of charges relying on the GeO2/Ge quality were modeled to correlate with the observed Ge band bending evolution, which would impact both the device operation and reliability.
关键词： band bending,x-ray photoemission spectroscopy,Ge-based electronics,charge characteristics
更新于2025-09-23 15:22:29
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Robust high-fidelity coherent control of two-state systems by detuning pulses
摘要： Coherent control of two-state systems is traditionally achieved by resonant pulses of specific Rabi frequency and duration, by adiabatic techniques using level crossings or delayed pulses, or by sequences of pulses with precise relative phases (composite pulses). Here we develop a method for high-fidelity coherent control which uses a sequence of detuning pulses. By using the detuning pulse areas as control parameters, and driving on an analogy with composite pulses, we report a great variety of detuning pulse sequences for broadband and narrow-band transition probability profiles.
关键词： composite pulses,narrow-band,coherent control,broadband,detuning pulses,two-state systems
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Band-Pass ARC-Filter Based on the Classical Wien Bridge with the Pole Frequency Rise and Independent Adjustment of the Main Parameters
摘要： A new topology of the band-pass active RC filter (BP) based on the classic Wien bridge is proposed. This scheme, implemented on two Op-Amps, is recommended for the use as a second-order link in more complex BPs. The analysis of the modified band-pass ARC filter is carried out, the main parameters of the BP are found. The computer simulation of the developed PF tuning algorithm is completed. The graphs of changes in the frequency response and phase response when changing various parameters of the BP are obtained. It is shown that in the considered BP an independent adjustment of the main parameters is ensured - transmission coefficient in the passband, pole attenuation and pole frequency.
关键词： ARC filter,trimming,active RC filter,band-pass RC filter,high-order BP,Wien bridge,parameter adjustment
更新于2025-09-23 15:22:29