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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 - Wind Field Retrieving for SCAT Onboard CFOSAT Based on PCA Method
摘要： The scatterometer (SCAT) onboard China France Oceanography Satellite (CFOSAT) will be the first scanning scatterometer with rotating fan-beams. Wind retrieving methods for existed scatterometers, which are with rotating pencil beams or fixed fan beams, are needed to be modified considering efficiency in information extraction from the numerous observations acquired in this working mode. This was achieved in the research of this paper by applying Principle Component Analysis (PCA) method. Firstly, vectors for applying PCA are composed in two different ways for analysis of the effectiveness of information extraction for the SCAT data and for wind retrieving respectively. Then the description of simulated SCAT data considering observing geometry and SCAT working mode was given. Then experiments of PCA based wind retrieving method was carried out with conclusion that it was effective in information extraction for preparing data sets for wind retrieving. Finally, further research has been discussed.
关键词： wind retrieval,principle component analysis (PCA),China-France Oceanography Satellite (CFOSAT),Scatterometer (SCAT),simulated data
更新于2025-09-09 09:28:46
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Investigations of Temporal and Spatial Distribution of Precursors SO<sub>2</sub> and NO<sub>2</sub> Vertical Columns in North China Plain by Mobile DOAS
摘要： Recently, Chinese cities have suffered severe events of haze air pollution, particularly in the North China Plain (NCP). Investigating the temporal and spatial distribution of pollutants, emissions, and pollution transport is necessary to better understand the effect of various sources on air quality. We report on mobile differential optical absorption spectroscopy (mobile DOAS) observations of 20 precursors SO2 and NO2 vertical columns in NCP in summer of 2013 (from 11 June to 7 July) in this study. The different temporal and spatial distributions of SO2 and NO2 vertical column density (VCD) over this area are characterized under various wind fields. The results show that the transport from southern NCP strongly affects the air quality in Beijing, and the transport route, particularly SO2 transport of Shijiazhuang–Baoding–Beijing is identified. In addition, the major contributors to SO2 along the route of Shijiazhuang–Baoding–Beijing are elevated sources and low area sources for the route of Dezhou–Cangzhou–Tianjin–Beijing are found using the interrelated analysis between in situ and mobile DOAS observations during the measurement periods. Furthermore, the discussion of hot spot near Ji’nan City shows that the average observed width of polluted air mass is 11.83 km and 17.23 km associated with air mass diffusion, which is approximately 60 km away from emission sources based on geometrical estimation. Finally, a reasonable agreement exists between OMI and mobile DOAS observations with correlation coefficient (R2) of 0.65 for NO2 VCDs. Both datasets also have similar spatial pattern. The fitted slop of 0.55 is significantly less than unity can reflect the contamination of local sources and OMI observations need to improve the sensitivities to the near-surface emission sources through the improvements of retrieval algorithm or resolution of satellites.
关键词： North China Plain,transport,air pollution,SO2,mobile DOAS,NO2
更新于2025-09-09 09:28:46
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Spatiotemporal dynamics of snow cover based on multi-source remote sensing data in China
摘要： By combining optical remote sensing snow cover products with passive microwave remote sensing snow depth (SD) data, we produced a MODIS (Moderate Resolution Imaging Spectroradiometer) cloudless binary snow cover product and a 500 m snow depth product. The temporal and spatial variations of snow cover from December 2000 to November 2014 in China were analyzed. The results indicate that, over the past 14 years, (1) the mean snow-covered area (SCA) in China was 11.3 % annually and 27 % in the winter season, with the mean SCA decreasing in summer and winter seasons, increasing in spring and fall seasons, and not much change annually; (2) the snow-covered days (SCDs) showed an increase in winter, spring, and fall, and annually, whereas they showed a decrease in summer; (3) the average SD decreased in winter, summer, and fall, while it increased in spring and annually; (4) the spatial distributions of SD and SCD were highly correlated seasonally and annually; and (5) the regional differences in the variation of snow cover in China were significant. Overall, the SCD and SD increased significantly in south and northeast China, and decreased significantly in the north of Xinjiang province. The SCD and SD increased on the southwest edge and in the southeast part of the Tibetan Plateau, whereas it decreased in the north and northwest regions.
关键词： remote sensing,passive microwave,MODIS,spatiotemporal dynamics,snow cover,China
更新于2025-09-09 09:28:46
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High-fluorescent carbon dots (CDs) originated from China grass carp scales (CGCS) for effective detection of Hg(II) ions
摘要： Carbon dots (CDs) as a kind of environment-friendly fluorescent nanomaterial has been actively studied because of wide and potential applications, such as bioimaging and biosensors. It is worth mentioning that preparing CDs from the recycling of carbonaceous waste has received considerable research interest. We proposed a simple carbon dots synthesis technique, that is, using China grass carp scales (CGCS) as original and green materials by a one-step microwave hydrothermal method to prepare CDs. Since the mercury ion has strongly sulphophile, S atoms display higher thermodynamic affinity and faster integrating process with Hg2+ ions. Due to the presence of large amount of cysteine-containing sulfhydryl groups, the obtained CGCS-CDs can be used as a specific fluorescence probe for detecting Hg2+ ions. Subsequently, CGCS-CDs were characterized by HR-TEM, XRD, FT-IR and XPS analyses. The optical properties of CGCS-CDs were elucidated by fluorescence and UV–vis spectra. Additionally, the effects of pH values and salt concentrations on optical properties of CGCS-CDs were also researched by fluorescence spectra. Under optimal conditions, the decrease of fluorescence intensity displays a good linear relationship with allowable Hg2+ ion detection concentration range of 0.014–30 μmol/L and a limit of detection (LOD) of 0.014 μmol/L is acquired. Meanwhile, the effect of other metal ions on the detection of Hg2+ ions by using CGCS-CDs as fluorescence probe was studied, suggesting that the CGCS-CDs could be an excellent fluorescence probe for the detection of Hg2+ ions. Eventually, the CGCS-CDs were proven to be low toxicity and applied for Hg2+ ions detection in lake water and cosmetic, demonstrating their potential towards diverse applications.
关键词： Sulfhydryl group,Microwave hydrothermal,Nanoscale sensing,Mercury,Carbon dots (CDs),China grass carp scales (CGCS)
更新于2025-09-09 09:28:46
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AIP Conference Proceedings [Author(s) 3RD INTERNATIONAL CONFERENCE ON MATERIALS SCIENCE, RESOURCE AND ENVIRONMENTAL ENGINEERING (MSREE 2018) - Changsha City, China (26–28 October 2018)] - Review of concentrating solar thermal power in China: Status quo, problems and countermeasures
摘要： Currently, the concentrating solar thermal power (CSP) has been confronted with great opportunity for further development. As a strategic emerging industry in China, the CSP meets the appeals of the Belt and Road strategy from manufacturing to practical applications. Therefore, to development the CSP in depth is of vital significance to promote power supply structure transformation, energy saving and emission reduction, as well as energy security in China. However, the development of China’s CSP industry at present is still at the initial stage, with a few problems seriously hindering the large-scale and sustainable development of the industry. In view of this, this paper systematically analyzes China’s CSP industry. Firstly, it conducts a detailed research on the industry status quo. On that basis, it deeply studies the existing issues and future development trend. Finally, it puts forward a series of feasible countermeasures, laying a solid foundation for the development of the CSP industry and the transformation of energy structure in China.
关键词： Concentrating Solar Thermal Power (CSP),China,Power Supply Structure Transformation,Renewable Energy
更新于2025-09-04 15:30:14
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Mercury Pollution, Treatment and Solutions in Spent Fluorescent Lamps in Mainland China
摘要： With the increasing awareness of energy conservation and environmental protection, high energy-consuming incandescent lamps have been largely withdrawn from the stage of mainland China’s lighting industry because the main raw material for electricity production-coal-produces mercury pollution when burned and energy-saving ?uorescent lamps have made considerable progress. However, ?uorescent lamps emit mercury, which still causes environmental pollution. In this work, the existing problems in the development of ?uorescent lamps, and in the collection and treatment of spent ?uorescent lamps were analyzed. The contributions of various external factors to the above problems were evaluated based on fuzzy theory. Finally, solutions to control the pollution of mercury from ?uorescent lamps and spent ?uorescent lamps were proposed. Results show that the biggest problem that causes mercury pollution is the ?rst among three factors: energy conservation and mercury emission from ?uorescent lamps and spent ?uorescent lamps, spent ?uorescent lamp collection and spent ?uorescent lamp treatment. The best way to solve these problems is by developing an energy-saving and environment-friendly light emitting diode (LED) industry in mainland China.
关键词： spent ?uorescent lamps,LED,treatment,mercury pollution,?uorescent lamps,mainland China
更新于2025-09-04 15:30:14
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Tropospheric NO<sub>2</sub>, SO<sub>2</sub>, and HCHO over the East China Sea, using ship-based MAX-DOAS observations and comparison with OMI and OMPS satellites data
摘要： In this study, ship-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements were performed in the Eastern China Sea (ECS) area in June 2017. The tropospheric Slant Column Densities (SCDs) of nitrogen dioxide (NO2), sulfur dioxide (SO2), and formaldehyde (HCHO) were retrieved from the measured spectra by the Differential Optical Absorption Spectroscopy (DOAS) technique. Using the simple geometric approach, the SCDs of different trace gases observed at 15° elevation angle were adopted to convert into tropospheric Vertical Columns Densities (VCDs). During this campaign, the averaged VCDs of NO2, SO2, and HCHO in the marine environment over ECS area are 6.50 × 1015 molec cm-2, 4.28 × 1015 molec cm-2 and 7.39 × 1015 molec cm-2, respectively. In addition, the ship-based MAX-DOAS trace gases VCDs were compared with satellite observations of Ozone Monitoring Instrument (OMI) and Ozone Mapping and Pro?ler Suite (OMPS). The daily OMI NO2 VCDs agree well with ship-based MAX-DOAS measurements showing the correlation coefficient R of 0.83. Besides, the good agreements of SO2 and HCHO VCDs between the OMPS satellite and ship-based MAX-DOAS observations were also found with correlation coefficient R of 0.76 and 0.69. The vertical profiles of these trace gases are achieved from the measured Differential Slant Column Densities (DSCDs) at different elevation angles using optimal estimation method. The retrieved profiles displayed the typical vertical distribution characteristics, which exhibits the low concentrations of < 3, < 3, and < 2 ppbv for NO2, SO2, and HCHO in clean area of the marine boundary layer far from coast of the Yangtze River Delta (YRD) continental region. Interestingly, elevated SO2 concentrations can be observed intermittently along the ship routes, which is mainly attributed to the vicinal ship emissions in the view of the MAX-DOAS measurements. Combined with the on-board ozone lidar measurements, the ozone (O3) formation was discussed with the vertical profile of HCHO/NO2 ratio, which is sensitive to the increases of NO2 concentration. This study provided further understanding of the main air pollutants in the marine boundary layer of the ECS area and also benefited to formulate the policies regulating the shipping emissions in such costal area like YRD region.
关键词： NO2,SO2,OMI,MAX-DOAS,OMPS,ship-based observations,HCHO,East China Sea
更新于2025-09-04 15:30:14