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- 摘要
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- 实验方案
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[IEEE 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Sarajevo, Bosnia and Herzegovina (2019.9.2-2019.9.4)] 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - How Dubai is Becoming a Smart City?
摘要： Quantitative retrieval is a growing area in remote sensing due to the rapid development of remote instruments and retrieval algorithms. The aerosol optical depth (AOD) is a significant optical property of aerosol which is involved in further applications such as the atmospheric correction of remotely sensed surface features, monitoring of volcanic eruptions or forest fires, air quality, and even climate changes from satellite data. The AOD retrieval can be computationally expensive as a result of huge amounts of remote sensing data and compute-intensive algorithms. In this paper, we present two efficient implementations of an AOD retrieval algorithm from the moderate resolution imaging spectroradiometer (MODIS) satellite data. Here, we have employed two different high performance computing architectures: multicore processors and a graphics processing unit (GPU). The compute unified device architecture C (CUDA-C) has been used for the GPU implementation for NVIDIA’s graphic cards and open multiprocessing (OpenMP) for thread-parallelism in the multicore implementation. We observe for the GPU accelerator, a maximal overall speedup of 68.x for the studied data, whereas the multicore processor achieves a reasonable 7.x speedup. Additionally, for the largest benchmark input dataset, the GPU implementation also shows a great advantage in terms of energy efficiency with an overall consumption of 3.15 kJ compared to 58.09 kJ on a CPU with 1 thread and 38.39 kJ with 16 threads. Furthermore, the retrieval accuracy of all implementations has been checked and analyzed. Altogether, using the GPU accelerator shows great advantages for an application in AOD retrieval in both performance and energy efficiency metrics. Nevertheless, the multicore processor provides the easier programmability for the majority of today’s programmers. Our work exploits the parallel implementations, the performance, and the energy efficiency features of GPU accelerators and multicore processors. With this paper, we attempt to give suggestions to geoscientists demanding for efficient desktop solutions.
关键词： High performance computing (HPC),OpenMP,quantitative remote sensing retrieval,graphics processing unit (GPU),Aerosol optical depth (AOD)
更新于2025-09-19 17:13:59
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A solid particle seeder for particle-based laser measurement techniques in low volume-flowrate gas streams
摘要： This article describes a device to seed solid micron-size particles into gases for particle-based laser diagnostic techniques. The particle seeder consists of a sealed vessel containing the particles, into which the gas to be seeded is introduced. Using an electric fan placed inside the vessel, a fine aerosol can be easily generated. It is demonstrated that (1) at a fixed fan speed the particle seeding density Np can be kept within the range 10–100 particles mm?3 across the gas volume flowrate range 0.05–5 LPM; and (2) at a fixed gas volume flowrate, the fan speed can be used for approximate adjustment of the particle seeding density in the range 1–100 particles mm?3. The device does not affect the volume flowrate of the gas stream. This simple method should prove useful for researchers wishing to generate solid particle aerosols in low volume flowrate gas streams.
关键词： PIV,velocimetry,particle seeding,LDV,aerosol
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - St. Petersburg, Russia (2019.10.17-2019.10.18)] 2019 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Laser ranging of the Atmospheric Aerosol and Determination of its Disperse Composition
摘要： It has been fulfilled the assessment of the differential easing method for the remote measurement of the aerosol pollution disperse composition parameters in the atmospheric boundary layer over the industrial enterprise. Laser attenuation signals at three wavelengths have been measured using the developed aerosol lidar system, from which average values of the volume and surface diameter of aerosol particles of cement have been obtained. The diameter average value of 0.61±0.04 μm and relative accuracy ε=11% have been calculated.
关键词： differential easing and scattering,aerosol lidar,laser radiation,particles average volume and superficial diameter
更新于2025-09-19 17:13:59
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34.3: <i>Invited Paper:</i> Printing Pixel Circuits on Light Emitting Diode Array for AMLED Displays
摘要： An active matrix light emitting display module integrated with carbon nanotubes control circuits was fully printed. The high performance of super pure single-chirality carbon nanotube TFT provides super bright and low power consumption technologies for indoor and outdoor augmented reality that are highly desirable for civil and military display applications.
关键词： Aerosol Jet Printing,Active Matrix LED Display Module,Single Chirality Semiconducting Single-Walled Carbon Nanotubes,Thin Film Transistors,Light Emitting Diode Array
更新于2025-09-16 10:30:52
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Fine-tuning of spark-discharge aerosol CVD reactor for single-walled carbon nanotube growth: the role of ex situ nucleation
摘要： We report a development of recently designed apparatus equipped with a spark discharge generator of catalytic nanoparticles for robust aerosol CVD synthesis of single-walled carbon nanotubes. We achieve a profound control over the diameter distribution and the defectiveness of carbon nanotubes produced. By providing a justified comparison of the apparatus with the most abundant aerosol CVD reactor utilizing ferrocene as a catalyst precursor, we reveal the role of the activation procedure: while spark-discharge generator provides aerosol of nanoparticles (ex situ route), the ferrocene vapor decomposes in the nanotube growth zone providing an in situ formation of the catalyst. With other parameters being equal, we reveal the differences in the nanotube growth (diameter and length distribution, yield, defectiveness) employing a comprehensive set of methods (the analysis of differential mobility of the aerosol particles, optical spectroscopy, scanning and transmission electron microscopy, Raman spectroscopy, and atomic force microscopy). We show the ex situ activation in the spark discharge reactor to provide a lower utilization degree of the nanoparticles due to over-coagulation. However, the same method provides an independence of the key performance parameters of the nanotubes opening a room for scaling the apparatus.
关键词： spark-discharge generator,differential mobility analyzer,aerosol CVD synthesis,catalyst activation,floating catalyst,single-walled carbon nanotubes
更新于2025-09-16 10:30:52
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Impact of environmental pollution on the retrieval of AOD products from Visible Infrared Imaging Radiometer Suite (VIIRS) over wuhan
摘要： Visible Infrared Imaging Radiometer Suite (VIIRS) is a next-generation polar-orbiting operational environmental sensor, and its aerosol optical depth (AOD) data has been widely applied to ground-level PM2.5 prediction and air pollution research. However, VIIRS performance affects the accuracy of prediction. In this study, three types of VIIRS AOD products were collected from January 2014 to December 2016 to evaluate their performance under different air quality conditions. Near-surface PM2.5 concentrations were determined for the same period to categorize air quality as clean, moderate, or heavily polluted. The performance of three VIIRS AOD products was evaluated from the successful retrieval rate and AOD accuracy aspects. For clean weather days, the AODs obtained from VIIRS intermediate products (IP) had the lowest average absolute bias (0.15 ± 0.15). For the moderate and heavy pollution days, the average absolute deviations of VIIRS environmental data record (EDR) AOD (Quality Flags = 3 and > 1) products were lowest at 0.14 ± 0.14 and 0.2 ± 0.1 respectively. These results suggest that the EDR AOD, Quality Flags > 1 and = 3, products were more suitable for heavy and moderate air pollution, respectively. During clean weather, performance of _IP AODs was found to be best. Moreover, seasonal analysis indicated that the EDR AOD (Quality Flags = 3) products were more suitable for spring and autumn and the IP AOD for summer. However, the performance of the EDR AOD products (Quality flags > 1) were best during winter. To ensure accuracy of PM2.5 predictions over central China, researchers should carefully balance the needs for successful retrieval rate and accuracy of VIIRS AOD products.
关键词： AOD,VIIRS,Sun photometer,Aerosol,Air quality
更新于2025-09-12 10:27:22
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Fiber Optic and Atmospheric Optical Communication || Atmospheric Communication Channels
摘要： The atmosphere is a gaseous envelope that surrounds the Earth from the ground surface up to several hundred kilometers. The atmosphere consists of different kinds of gaseous, liquid, and crystal structures, including effects of gas molecules (atoms), aerosol, cloud, fog, rain, hail, dew, rime, glaze, and snow. Except for the first two, the others are usually called hydrometeors in the literature. Furthermore, due to irregular and sporadic air streams and motions, that is, irregular wind motions, chaotic structures defined as atmospheric turbulence are also present in the atmosphere.
关键词： Hydrometeors,Atmosphere,Aerosol,Turbulence,Optical Communication
更新于2025-09-12 10:27:22
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15.4: Fabrication of 5.5‐inch AMOLED Panel using IGZO TFTs
摘要： Naphthalene (Nap) and methylnaphthalene (MN) are the most abundant polycyclic aromatic hydrocarbons (PAHs) in atmosphere and have been proposed to be important precursors of anthropogenic secondary organic aerosol (SOA) derived from laboratory chamber experiments. In this study, atmospheric Nap/MN and their gas-phase photooxidation products were quanti?ed by a Proton Transfer Reaction-Quadrupole interface Time-of-Flight Mass Spectrometer (PTR-QiTOF) during the 2016 winter in Beijing. Phthalic anhydride, a late generation product from Nap under high-NOx conditions, appeared to be more prominent than 2-formylcinnamaldehyde (early generation product), possibly due to more su?cient oxidation during the haze. 1,2-Phthalic acid (1,2-PhA), the hydrated form of phthalic anhydride, was capable of partitioning into aerosol phase and served as a tracer to explore the contribution of Nap to ambient SOA. The measured fraction in particle phase (Fp) of 1,2-PhA averaged at 73 ± 13% with OA mass loadings of 52.5?87.8 μg/m3, lower than the value predicted by the absorptive partitioning model (100%). Using tracer product-based and precursor consumption-based methods, 2-ring PAHs (Nap and MN) were estimated to produce 14.9% (an upper limit) of the SOA formed in the afternoon during the wintertime haze, suggesting a comparable contribution of Nap and MN with monocyclic-aromatics on urban SOA formation.
关键词： PTR-QiTOF,Secondary Organic Aerosol,Beijing,Haze Events,Naphthalene,Methylnaphthalene
更新于2025-09-11 14:15:04
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Search for Best Astronomical Observatory Sites in the MENA Region using Satellite Measurements
摘要： We perform a systematic search for astronomical observatory sites in the MENA (Middle-East and North Africa) region using space-based data for all the relevant factors, i.e. altitude (DEM), cloud fraction (CF), light pollution (NTL), precipitable water vapor (PWV), aerosol optical depth (AOD), relative humidity (RH), wind speed (WS), Richardson Number (RN), and diurnal temperature range (DTR). We look for the best locations overall even where altitudes are low (the threshold that we normally consider being 1,500 m) or where the combination of the afore-mentioned determining factors had previously excluded all locations in a given country. In this aim, we use the rich data that Earth-observing satellites provide, e.g. the Terra and Aqua multi-national NASA research satellites, with their MODIS (Moderate Resolution Imaging Spectroradiometer) and AIRS (Atmospheric Infrared Sounder) instruments, the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS), and other products from climate diagnostics archives (e.g. MERRA). We present preliminary results on the best locations for the region.
关键词： diurnal temperature range,Richardson Number,MENA region,wind speed,precipitable water vapor,cloud fraction,relative humidity,aerosol optical depth,light pollution,astronomical observatory sites,satellite measurements
更新于2025-09-11 14:15:04
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Seasonal aerosol variations over a coastal city, Zhoushan, China from CALIPSO observations
摘要： This paper presents the observed seasonal aerosol variations over Zhoushan, an eastern coastal Chinese city. Data were obtained from the Cloud – Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite from the period of June 2007 to May 2017. We compared the columnar Aerosol Optical Depth (AOD) data from the CALIPSO and MODerate resolution Imaging Spectroradiometer (MODIS). Results showed good consistency, but the former was systematically lower than the latter. The temporal distribution of columnar AOD showed significant variations with the highest in spring and lowest in summer. Similarly, the seasonal scatter plots suggested that the highest correlation coefficient was 0.56 in winter and summer, followed by the autumn (0.53), and spring (0.40) seasons. In addition, the results revealed that the polluted dust and polluted continental aerosols (38.9% and 30.5%, respectively) were dominant aerosol subtypes observed in winter, whereas, the polluted dust (47.2%) aerosol subtype was found dominant in spring. The polluted continental aerosol subtype appeared dominant during the summer and autumn seasons, with the frequencies of about 56.0% and 47.4%, respectively. These findings can be reasonably explained using the air mass cluster analysis computed for the obtained backward trajectories derived from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Furthermore, the aerosol vertical extinction coefficient measured at the wavelength of 532 nm was found to be highest near the surface (~0.2 km-1) in winter and autumn and decreased sharply as the altitude increased indicating that aerosols were present at an altitude <2 km. However, during spring, the values of extinction coefficient remained >0.15 km-1 at an altitude range of 0–3.5 km due to convection and strong vertical mixing lifting aerosols to slightly higher levels. Furthermore, during the spring, approximately 54% of the particulate depolarization ratio (PDR) values were ≤ 0.2, and the remaining 46% of the PDR were > 0.2, suggesting both spherical and irregular particles were present in the atmosphere.
关键词： MODIS,Aerosol Optical Depth,CALIPSO,Extinction Coefficient,East China,Aerosol subtype
更新于2025-09-10 09:29:36