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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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A combined geographical information system and Best–Worst Method approach for site selection for photovoltaic power plant projects
摘要： Site selection is one of the most important components of the execution of a solar photovoltaic power plant. The main aim of this study is to introduce an evaluation model for determining the optimal location for a photovoltaic project, based on Geographic Information System with a Multi-Criteria Decision-Making approach. The model takes into account various measures in three categories, namely climatic, location, and orography, to ensure select the best location from execution and technical points of view. Best–Worst Method, as a novel scheme, is employed for prioritization of criteria, in which the best and worst criteria play a significant role in decision making. After excluding restricted areas, weighted criteria are used to produce the necessary maps by GIS. Land suitability index is also defined and used to classify lands into five different groups. China’s capital, Beijing, is evaluated as a case study by focusing on the available data. SolarGIS maps as well as several ArcGIS tools are used in this study. The obtained results suggest that 27.4% of the studied region, mainly on the northern and northeastern parts of Beijing, is suitable for establishing these projects. Furthermore, based on land suitability index results, 61.96% of the suitable regions is classified as the “most suitable” category, whereas 27.14% is found to be “very suitable”. In the end, the proposed approach is found to be effective and compatible with the subject of this study.
关键词： Air pollution,Multi-criteria decision making,Solar energy,Renewable energy,Beijing
更新于2025-09-11 14:15:04
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Aerosol Retrievals Over Bright Urban Surfaces Using Landsat 8 Images
摘要： Aerosols, suspended particles in the atmosphere, play an important role in the formation of cloud nuclei, climate change, poor air quality and degradation of atmospheric visibility, and public health and diseases. For a full understanding of aerosols effects on urban air quality and public health, retrieval of aerosol optical properties such as aerosol optical depth (AOD) over bright urban surfaces is required. In this study, Landsat 8 Operational Land Imager (OLI) cloud-free images at 30 m spatial resolution were obtained from 2013 to 2017 for the blue (483 nm), green (560 nm) and red (660 nm) channels to retrieve AOD using the Simplified Aerosol Retrieval Algorithm (SARA). The Minimum Reflectance Technique (MRT) was applied on the composite of Landsat surface reflectance images to estimate surface reflectance for AOD retrievals. Validation of the high-resolution AOD retrievals was conducted against two AERONET (AErosol RObotic NETwork) sites located at bright urban surfaces of Beijing. The quality and error of the AOD retrievals were reported using the Expected Error (EE = ± (0.05 + 20%)), root mean square error (RMSE), and relative percent mean error (RPME). Results showed that the Landsat 8 AOD retrievals were well-correlated R = 0.98) with the AERONET AOD measurements for each channel with 75% of the retrievals were within the EE, RMSE of 0.11 and RPME of 7%. These results suggest that the SARA algorithm is robust and useful to retrieve high-resolution AOD observations and Landsat 8 can be used for aerosols monitoring over bright urban surfaces of Beijing, which is frequently affected by severe dust storms and haze pollution, to identify their effects on public health.
关键词： AERONET,Landsat 8,Beijing,AOD,SARA
更新于2025-09-09 09:28:46
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Comparison of mixing layer height inversion algorithms using lidar and a pollution case study in Baoding, China
摘要： Beijing–Tianjin–Hebei area is suffering from atmospheric pollution from a long time. The understanding of the air pollution mechanism is of great importance for officials to design strategies for the environmental governance. Mixing layer height (MLH) is a key factor influencing the diffusion of air pollutants. It plays an important role on the evolution of heavy pollution events. Light detection and ranging (lidar), is an effective remote-sensing tool, which can retrieve high spatial and temporal evolution process within mixing layer (ML), especially the variation of MLH. There are many methods to retrieve MLH, but each method has its own applicable limitations. The Mie-lidar data in Beijing was firstly used to compare three different algorithms which are widely used under different pollution levels. We find that the multi-layer structure near surface may cause errors in the detection of mixing layer. The MLH retrieved based on image edge detection was better than another two methods especially under heavy polluted episode. Then we applied this method to investigate the evolution of the mixing layer height during a pollution episode in December 2016. MLH at Gucheng county showed the positive correlation with the concentration of particulate matters during the start of this pollution episode. The elevated pollution level in Gucheng was not associated with MLH's decrease, and the significantly increased particulate matters raised the boundary layer, which trapped the pollutants near the surface.
关键词： Mixing layer,Beijing–Tianjin–Hebei area,Severe haze
更新于2025-09-09 09:28:46