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- 2019
- photovoltaic power generation system
- sensitivity analysis
- Monte Carlo
- fuzzy layering evaluation method
- Electrical Engineering and Automation
- Xi’an Jiaotong University
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[IEEE 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Budapest (2018.7.1-2018.7.5)] 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Modelling Charge Generation and Transport in Low Density Polyethylene Irradiated by an Electron-Beam
摘要： One way to bypass charge generation due to injection in an insulator sandwiched between parallel electrodes and submitted to an applied voltage is to implant charges in the material with the help of an electron beam. The electrons position and quantity is theoretically known as long as the beam energy and beam current are known. Low density polyethylene (LDPE) has been characterized with in-situ space charge measurements by pulsed electroacoustic method during irradiation, and with ex-situ measurements while a DC voltage is applied. A fluid charge transport model has been developed using a commercial software, to reproduce the space charge behaviour during and after irradiation. Simulated results during irradiation are first compared to in-situ space charge measurements, in order to validate the model parameters related to e-beam irradiation. Simulations are then performed on post-irradiated samples, polarized under different electric fields. Space charge measurements and current measurements are available for comparison. Simulated results are in relatively good agreement with experimental ones as long as the model parameters are adapted to irradiated low density polyethylene, compared to a best set of parameters adapted uniquely for non-irradiated polyethylene.
关键词： charge generation and transport,fluid model,LDPE,ageing,electron-beam irradiation
更新于2025-09-23 15:22:29
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Changes in the Collagen Structure of Thyroid Nodule Capsules Determined by Polarization-Resolved Second Harmonic Generation Microscopy
摘要： Thyroid carcinomas represent a challenging problem as their differentiation from the much more frequent benign pathologies can be sometimes difficult. Automatic diagnostic approaches that can differentiate between malignant and benign thyroid nodules would be of great benefit for addressing thyroid pathologies. In this study we have used polarization-resolved second harmonic generation microscopy to investigate collagen organization in the fibrillar capsules surrounding human thyroid nodules. We demonstrate that imaging the collagen capsules at different laser beam polarization angles and fitting the second harmonic generation intensity with a theoretical curve can yield information on the nonzero components of the second order susceptibility tensor and the orientation of the collagen fibres. We have used this approach to differentiate between capsules surrounding the thyroid follicular adenoma and papillary carcinoma nodules. These results indicate that polarization-resolved second harmonic generation microscopy can provide additional information about the collagenous capsule surrounding thyroid nodules, which may complement intensity-based quantitative second harmonic generation microscopy and eventually traditional histopathologic examination.
关键词： second harmonic generation,thyroid nodules,collagen
更新于2025-09-23 15:22:29
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Liquid exfoliation of g-C3N4 nanosheets to construct 2D-2D MoS2/g-C3N4 photocatalyst for enhanced photocatalytic H2 production activity
摘要： Although graphitic carbon nitride (g-C3N4) is an attractive photocatalyst for solar H2 generation, the preparation of g-C3N4 nanosheets via a “green” and simple method as well as the construction of highly-efficient g-C3N4-based photocatalysts are still challenges. In this study, g-C3N4 nanosheets prepared by a simple probe sonication assisted liquid exfoliation method were used to construct 2D-2D MoS2/g-C3N4 photocatalyst for photocatalytic H2 production. The 2D-2D MoS2/g-C3N4 photocatalyst containing 0.75% MoS2 showed the highest H2 evolution rate of 1155 μmol·h-1·g-1 with an apparent quantum yield of 6.8% at 420 nm monochromatic light, which is much higher than that of the optimized 0D-2D Pt/g-C3N4 photocatalyst. The high photocatalytic H2 production activity of 2D-2D MoS2/g-C3N4 photocatalyst can be attributed to the large surface area and the formed 2D interfaces between MoS2 and g-C3N4 nanosheets. As demonstrated by photoluminescence quenching and time-resolved fluorescence decay studies, the 2D interfaces can accelerate the photoinduced charge transfer, resulting in the high photocatalytic H2 production performance. This study provides a new strategy in developing highly-efficient g-C3N4-based photocatalysts for H2 production via using 2D nanojunction as a bridge to promote the photoinduced charge separation and transfer.
关键词： Hydrogen generation,Molybdenum disulfide,Graphitic carbon nitride,Photocatalysis,2D photocatalyst
更新于2025-09-23 15:22:29
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Automatic robot path integration using three-dimensional vision and offline programming
摘要： In manufacturing industries, offline programming (OLP) platforms provide an independent methodology for robot integration using 3D model simulation away from the actual robot cell and production process, reducing integration time and costs. However, traditional OLP platforms still require prior knowledge of the workpiece position in a predefined environment, which requires complex human operations and specific-purpose designs, highly reducing the autonomy of the systems. The presented approach proposes to overcome these problems by defining a novel automated offline programming system (AOLP), which integrates a flexible and intuitive OLP platform with a state-of-the-art autonomous object pose estimation method, to achieve an environment and model independent platform for automatic robotic manufacturing. The autonomous recognition capabilities of the three-dimensional vision system provide the relative position of the workpiece model in the OLP platform, with robustness against clutter, illumination, and object material. After that, the user-friendly OLP platform allows an efficient and automatic path generation, simulation, robot code generation, and robot execution. The proposed system precision and robustness are analyzed and validated in a real-world environment on four different sets of experiment. Finally, the proposed system's features are discussed and compared with other available solutions for practical industrial manufacturing, showing the advantages of the proposed approach. Overall, despite sensor resolution limitations, the proposed system shows a remarkable precision and promising direction towards highly efficient and productive manufacturing solutions.
关键词： Machine vision,Path generation,Industrial manipulator,Automated offline programming,3D object recognition,6D pose estimation
更新于2025-09-23 15:22:29
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Enhancing the performance of photo-bioelectrochemical fuel cell using graphene oxide/cobalt/polypyrrole composite modified photo-biocathode in the presence of antibiotic
摘要： Photo-bioelectrochemical fuel cell (PBFC) holds a great potential to harvest sustainable electrical energy from wastewater, but low power output limits its applications due to poor electrochemical performance of photo-biocathode. Additionally, antibiotics are ubiquitous in wastewater streams, but little is known regarding their effects on photo-biocathode performance of the PBFC. This study attempted to increase power output of PBFC through improvement of the photo-biocathode performance by modifying the biocathode with graphene oxide/cobalt/polypyrrole (GO/Co/PPy) composite in the presence of oxytetracycline. The GO/Co/PPy composite modified electrode fabricated by one-step electropolymerization method exhibited more excellent catalytic activity toward oxygen reduction compared to Co-alone and Co/PPy modified electrode. The PBFC with GO/Co/PPy composite modified biocathode produced a maximum power density of 19 mW/m2, which was almost 4-fold higher than that produced with the bare biocathode (4.9 mW/m2) due to improved bio-electrocatalytic performance of the bicathode by the GO/Co/PPy composite. The maximum power density of the PBFC was further increased 4.6 (105.5 mW/m2), 3.7 (88.7 mW/m2), 2.9 (74.6 mW/m2) and 1.9 (56 mW/m2) fold by exposure to 5, 10, 20, and 50 mg/L OTC, respectively. The further increases in power was due to reduced cathode's charge transfer resistance using degradation products of OTC as mediators and OTC-stimulated growth of species with extracellular electron transfer ability. However, the photosynthesis and growth of alga was negatively affected by OTC concentration higher than 10 mg/L, resulting performance deterioration of bicathode.
关键词： Photo-bioelectrochemical fuel cell,Electrode modification,Oxytetracycline,Performance improvement,Power generation
更新于2025-09-23 15:22:29
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An optimization model for quadratic flow thinning – a traffic protection mechanism for FSO networks
摘要： Flow thinning (FT) is an active traffic protection mechanism destined for communication networks with variable capacity of links, for example wireless networks. In FT, end-to-end traffic demands are equipped with dedicated logical tunnels (for example MPLS tunnels) whose maximal capacities are subject to thinning in order to follow the fluctuations of the currently available link capacities. It follows that for each demand the instantaneous traffic realized between its end nodes must accommodate to the current total capacity available on its dedicated tunnels. In the paper we develop an optimization model for network dimensioning for an applicative modification of FT, the so called Quadratic Flow Thinning (QFT), and present a solution algorithm based on the path generation method. We derive relevant pricing problems for basic variants of the QFT mechanism (and for its special case Affine Flow Thinning, AFT), and present a numerical study that illustrates efficiency of the optimization algorithm, as well as compares the network cost for different variants of QFT and AFT.
关键词： Free space optics,Linear and mixed-integer programming,Resilient networks,Multicommodity flows,Quadratic and affine routing,Variable link capacity,Path generation
更新于2025-09-23 15:22:29
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Self-Floating Carbonized Tissue Membrane Derived from Commercial Facial Tissue for Highly Efficient Solar Steam Generation
摘要： Solar steam generation holds a great promise for practically utilizing solar energy in sea water desalination and sewage purification on a large scale. It has been proven that local heating of the superficial water can maximize the energy efficiency for steam generation. So the photothermal materials are required to float on water while working. However, the fabrication of a photothermal material with self-floating ability, low cost and easy-preparation for solar steam generation is highly challenged. Herein, self-floating carbonized tissue membrane for high efficiency solar steam generation is prepared via the carbonization of the commercial facial tissue. The low-cost and scalable carbonized tissue membrane can float on water without any assistance, and can effectively generate water steam at the rate of 4.45 kg m-2 h-1 with photothermal conversion efficiency of as high as 95 % under 3-sun illumination. The self-floating ability, high solar steam generation performance and low cost make the carbonized tissue membrane to be potential alternative for practical application in the future.
关键词： Self-floating,Membrane,One-step synthesis,Carbon material,Solar steam generation
更新于2025-09-23 15:22:29
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Bulk-or-interface assignment of heterodyne-detected chiral vibrational sum frequency generation signal by its polarization dependence
摘要： Polarization dependence of heterodyne-detected chiral vibrational sum frequency generation (VSFG) was examined for thin films of polylactic acids and neat limonene liquid far from electronic resonance. The enantiomers of polylactic acid films on silica substrates were successfully distinguished, and their chiral VSFG signals were ascribed not to bulk but to the interfaces by comparing chiral signals observed in reflection in the S-polarized VSFG, P-polarized visible, and P-polarized infrared and P-polarized VSFG, S-polarized visible, and P-polarized infrared polarization combinations with theoretical model calculations. In the same way, the chiral VSFG signal of neat limonene was assigned to bulk, which is consistent with the previous assignment. The method employed for assigning the source of chiral signals to the bulk or the interface may be useful for organic films on substrates with low refractive indices and thick samples.
关键词： limonene,chiral vibrational sum frequency generation,polarization dependence,bulk-or-interface assignment,heterodyne detection,polylactic acid
更新于2025-09-23 15:22:29
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Easy-to-operate fabrication of tapered glass capillaries for microdroplet generations
摘要： Tapered glass capillaries play an important role in micro droplets generation and related micro?uidic applications such as particle synthesis, digital PCR, microrectors. However, its controlled production poses a challenge. Speci?cally, there is di?culty controlling the tip sizes of capillaries with good repeatability at an a?ordable cost, which is critical to producing standard droplets for use by research groups. To produce tapered capillaries, micro needle geometries are ?rst pulled by commercial pipette puller, which yields a sharp tip (i.e. 1-3μm). Those tips need to be enlarged and standardized by post microfabrication. Although larger tips could be achieved by advanced pulling-forging, sanding-forging or breaking-forging methods, the uniformity and repeatability do not meet the requirements for mass production. In this paper, several easy-to-operate fabrication approaches, including mechanical and chemical fabrication methods, are studied. Chemical etching fabrication method shows good repeatability and robust control of dimensions. A capillary droplet micro?uidic device assembled by tapered glass capillaries fabricated by chemical etching method is also presented, which shows good performance for droplet generations. This non-labor intensive fabrication is straightforward and be readily adopted for industrial scale mass production.
关键词： glass capillary,micro fabrication,taper,droplet generation
更新于2025-09-23 15:22:29
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Atmospheric Profile Retrieval Algorithm for Next Generation Geostationary Satellite of Korea and Its Application to the Advanced Himawari Imager
摘要： In preparation for the 2nd geostationary multi-purpose satellite of Korea with a 16-channel Advanced Meteorological Imager; an algorithm has been developed to retrieve clear-sky vertical profiles of temperature (T) and humidity (Q) based on a nonlinear optimal estimation method. The performance and characteristics of the algorithm have been evaluated using the measured data of the Advanced Himawari Imager (AHI) on board the Himawari-8 of Japan, launched in 2014. Constraints for the optimal estimation solution are provided by the forecasted T and Q profiles from a global numerical weather prediction model and their error covariance. Although the information contents for temperature is quite low due to the limited number of channels used in the retrieval; the study reveals that useful moisture information (2~3 degrees of freedom for signal) is provided from the three water vapor channels; contributing to the increase in the moisture retrieval accuracy upon the model forecast. The improvements are consistent throughout the tropospheric atmosphere with almost zero mean bias and 9% (relative humidity) of root mean square error between 100 and 1000 hPa when compared with the quality-controlled radiosonde data from 2016 August.
关键词： optimal estimation,next generation geostationary imager,total precipitable water,clear sky atmospheric profile retrieval,Himawari AHI,information contents
更新于2025-09-23 15:22:29