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For surface features in short-wave infrared (SWIR, 1.3–3.0 μm) in remote sensing imagery, pixel values depict the total energy including reflection and emission. For surface features at normal temperature in SWIR band, emission energy can be ignored. While for surface features at high temperature in SWIR band, emission energy is equal to or even higher than the reflection energy. So remote sensing imagery of SWIR band can be used to separate emission and reflection energy as well as to realize temperature retrieval of high temperature targets. In this study, the seventh band (SWIR band) of Landsat8 OLI remote sensing imagery is used to perform the theoretical model research for temperature retrieval of high temperature targets. In the meantime, it is also used with the corresponding observation experiment of synchronization satellite to check the theoretical model. The result shows that the radiant flux density for mixed pixels with high temperature targets is higher than adjacent pixels without high temperature targets. Thus, the high temperature pixels can be identified in SWIR band. The retrieval results of temperature and fractional area for high temperature targets are consistent with reality. In the study, the result illustrates that it is effective to identify high temperature targets in remote sensing imagery of SWIR band and the model is appropriate for temperature retrieval use. 相似文献
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《Planetary and Space Science》2007,55(9):1190-1196
The Swedish Institute of Space Physics is developing a miniature plasma analyzer for planetary missions (MIPA—Miniature ion precipitation analyzer). MIPA has been accepted to fly on-board both the ESA BepiColombo mission to Mercury (2014) and the Indian Chandrayaan—1 mission to the Moon (2007). The analyzer measures ions in the energy range 10 eV–15 keV and has a sufficient mass resolution to resolve the main groups of ions, namely . Field of view is . The instrument consists of the sensor head and a separate electronic board whose total mass is 300 g. The sensor head envelope is roughly in volume and is designed for the extreme operation temperature range of to . MIPA comprises an electrostatic scanner for angular resolution, a cylindrical electrostatic analyzer for energy discrimination and a time-of-flight (TOF) section for particle velocity measurement. Generic design allows using the instrument on various platforms including nano-satellite and multi-spacecraft missions. This document describes the design of the sensor part including ion optical as well as mechanical aspects. 相似文献
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铀产品中杂质元素的含量测定在核法证学溯源分析或燃料元件厂质量检验中具有重要应用价值,保证测量的准确度主要在于控制流程空白、提高杂质元素的回收率。本文建立了戊基磷酸二戊酯(UTEVA)树脂快速分离铀与杂质元素、电感耦合等离子体质谱法(ICP-MS)测定杂质元素含量的系统流程。结果表明,UTEVA树脂对铀的吸附能力强,铀样品取样量为16.43 mg时,全流程对铀的去污因子大于3×105,9种杂质元素(锰钼镍铜铬铝钛钒镉)的回收率为95.1%~105.1%,国家标准物质GBW04205中杂质元素的分析结果与参考值在不确定度(k=2)范围内一致。本工作建立的分离流程对铀的去污效果好,特别适用于样品量少的情况下铀中杂质元素的分析,为核法证分析最终的归因溯源或燃料质量检验提供了技术支持。 相似文献
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首先回顾了地震概率安全评价(Seismic Probability Safety Assessment,SPSA)方法的发展历史及应用现状;然后基于SPSA的要素,研究了SPSA方法中需要解决的主要问题,重点是地震易损性分析,并根据SPSA的任务描述SPSA流程,主要探讨电厂走访和继电器评价的方法;最后结合我国概率安全评价(Probability Safety Assessment,PSA)的研究进展、SPSA的基础等实际状况,提出适合我国的SPSA实施路线的建议,以保障核电站地震情况下的安全. 相似文献
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Several caves of the Guangxi Zhuang Autonomous Region, southern China, have delivered Gigantopithecus blacki remains, an extinct Pleistocene giant ape, in association with abundant mammalian faunas. To determine their geological ages, fossil teeth from Mohui and Sanhe Caves were dated using the coupled ESR/U-series method. The teeth from Mohui Cave gave age estimates of 1.69 ± 0.22 Ma and 1.29 ± 0.11 Ma. The Sanhe Cave samples had age estimates ranging from 910 ± 200 ka to 600 ± 150 ka with error weighted mean ages of 890 ± 130 ka and 720 ± 90 ka for the layers 5 and 4, respectively. Our results and previous paleomagnestism data place the Gigantopithecus fauna at Mohui Cave between Olduvai and Jaramillo subchrons and suggest that it was coeval with Chuifeng, Longgupo and Liucheng assemblages. The Sanhe fauna is younger, of late early Pleistocene age, and can be dated to the period between Jaramillo subchron and B/M boundary. 相似文献
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Chun-Ru Liu Gong-Ming Yin Lu Gao Jean-Jacques Bahain Jian-Ping Li Min Lin Shi-Ming Chen 《Quaternary Geochronology》2010,5(2-3):385-390
The well-developed, late Cenozoic Nihewan Beds in northern China are amongst the most famous and well-preserved Quaternary strata in East Asia. The Nihewan Basin is also well-known for its mammalian fossils and stone artifacts, which document early human settlements in high northern latitudes (around 40°N). It is a key geological place to study palaeoenvironments and ancient human activities due to the excellent age-control of the formation by palaeomagnetism. In the present paper, the sediments of two Paleolithic sites were dated using the ESR signals of the titanium center in quartz. In order to check the reliability of our analytical procedures, a reference sample collected near the Brunhes/Matuyama (B/M) boundary at the Donggutuo site was firstly analyzed, yielding an age of 750 ± 88 ka. Then, three samples collected from the Dongpo site were analyzed by the same procedures. Our ESR results indicate that the age of the Dongpo cultural layer ranges between 304 ± 12 ka and 333 ± 23 ka, with an average of approximately 321 ± 15 ka. 相似文献
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In a high-level radioactive waste (HLW) repository, pH has an impact on the solubility, migration, and adsorption of radionuclides. Thus, understanding the effects of pH on the diffusion of radionuclides is essential for long-term disposal of HLW. In this work, the diffusion behaviors of Re(VII) and Se(IV) in compacted Gaomiaozi (GMZ) bentonite at different pH have been investigated by a through-diffusion method. The effective diffusion coefficient, i.e., De values of Re(VII) and Se(IV) were in the range of (1.0–2.4) × 10−11 m2/s at pH 3.0–10.0 and (0.38–2.3) × 10−11 m2/s at pH 3.0–9.0. In the case of Re(VII), the De values remained almost unchanged probably because ReO4− was the dominant species in the pH range of 3.0–10.0. In the case of Se(IV), whose predominant species were HSeO3− at pH < 9.0 and SeO32− at pH ≥ 9.0, the De values decreased by a factor of 3–6 at pH 9.0, i.e., De (pH < 9.0)/De (pH 9.0) ≈ 3–6, implying that the species with a higher valence state had a stronger anion exclusion effect. The decrease in De values can be explained by the diffusion species of Se(IV). Additionally, the rock capacity factor α decreased with the increase of pH. HSeO3− was absorbed on GMZ bentonite with distribution coefficient Kd values in the range of (1.0–2.5) × 10−4 m3/kg at pH ≤ 8.0, whereas SeO32− was negligibly sorbed at pH > 8.0. 相似文献