Retrieval of Brown Carbon based on the aerosol complex refractive indices in the winter of Wuhan     

Yuyao Zhang  Wei Gong 《地球空间信息科学学报》2017,20(4):319-324

Abstract

The impact of Brown Carbon (BrC) to aerosol light absorption has been paid more attention recently and there are a large number of studies showing that the influence of BrC on radiative forcing should not be ignored. BrC also acts as an important component of haze pollution which is occurring frequently in Wuhan, China. Therefore, it is essential to estimate their optical properties, composition, and mass concentration. Considering most haze pollution happens during the coldest time, we retrieved BrC columnar content during winter in Wuhan for the first time. Our method bases on the fact that BrC showed the strong spectral dependence on UV-light absorption. Using this method, we found that BrC makes up the small proportions of total aerosol volume (less than 10%). In the winter of 2011, we retrieved the daily-averaged columnar-integrated mass concentration of BrC on clear day is 4.353 mg/m² while that of haze day is 12.750 mg/m². According to the sensitivity study, we found that the results highly relied on the assumed aerosol refractive index. To reduce the uncertainty of this approach, we need to gain a better understanding of the temporal variability of the radiation absorbing components of these aerosols in the future.  相似文献   

火山气体喷发量的一种计算方法——以汉诺坝浮岩为例     

夏成  朱永峰  王海华  鲍景新 《矿物岩石地球化学通报》1998,(2)

火山气体喷发量的一种计算方法———以汉诺坝浮岩为例夏成朱永峰王海华鲍景新（北京大学地质系,北京１００８７１）关键词浮岩二相分流气体喷发量以火山方式将地幔气体排出是地球内部向地表输出的一条重要途径。火山喷发过程中流体（岩浆及地幔气体）带出大量动能,喷出...  相似文献   

冲绳海槽浮岩的蚀变作用原因     

翟世奎 《矿物学报》1995,15(3):360-364

在冲绳海槽海底浮岩的蚀变中ＳｉＯ２和Ｎａ２Ｏ相对含量明显减少，而Ｆｅ２Ｏ３、ＴｉＯ２、ＣａＯ、ＭｇＯ、ＣＯ２、ＭｎＯ和Ｐ２Ｏ５含量则明显增加；Ａｌ２Ｏ３、Ｋ２Ｏ、ＦｅＯ含量基本保持不变。蚀变作用导致了赤铁矿、针铁矿和非晶质Ｆｅ、Ｍｎ氧化物和绿泥石等粘土矿物的生成。多数微量元素的含量在蚀变样品中增加，尤其是Ｃｒ、Ｃｏ、Ｘｃ、Ａｓ、Ｂｒ、Ｒｂ和Ｔｈ。除Ｎｄ外轻稀土元素含量增加，大部分重稀土元素含量减小  相似文献   

Empirical and numerical analyses of support requirements for a diversion tunnel at the Boztepe dam site, eastern Turkey     

Zulfu Gurocak  Pranshoo Solanki  Musharraf M. Zaman 《Engineering Geology》2007,91(2-4):194-208

This paper presents the engineering geological properties and support design of a planned diversion tunnel at the Boztepe dam site that contains units of basalt and tuffites. Empirical, theoretical and numerical approaches were used and compared in this study focusing on tunnel design safety. Rock masses at the site were characterized using three empirical methods, namely rock mass rating (RMR), rock mass quality (Q) and geological strength index (GSI). The RMR, Q and GSI ratings were determined by using field data and the mechanical properties of intact rock samples were evaluated in the laboratory. Support requirements were proposed accordingly in terms of different rock mass classification systems. The convergence–confinement method was used as the theoretical approach. Support systems were also analyzed using a commercial software based on the finite element method (FEM). The parameters calculated by empirical methods were used as input parameters for the FEM analysis. The results from the two methods were compared with each other. This comparison suggests that a more reliable and safe design could be achieved by using a combination of empirical, analytical and numerical approaches.  相似文献   

Tsunami washover deposits, Tawharanui, New Zealand     

W.P. de Lange  V.G. Moon 《Sedimentary Geology》2007,200(3-4):232-247

Barrier dunes on the northern side of the Tawharanui Peninsula, north of Auckland, New Zealand, appear to have been overtopped by extreme waves that have deposited two large sand washover lobes in a back beach wetland. Present-day storm surges and storm waves are incapable of overtopping the barrier dunes. However, historical data and numerical models indicate tsunamis are amplified by resonance within the adjacent bay and Hauraki Gulf. Further, the location of nearshore reefs in close proximity to the washover lobes suggests that the interaction between tsunamis and the reefs further amplified the waves at those locations. The presence of a distinctive pumice (Loisels Pumice) within the washover deposits suggests that the deposits are associated with a 15th Century eruption from the submarine Mt Healy caldera located northeast of New Zealand.  相似文献   

Fiamme textures in volcanic successions: Flaming issues of definition and interpretation     

Katharine F. Bull  Jocelyn McPhie 《Journal of Volcanology and Geothermal Research》2007

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Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough     

HUANG Peng  LI Anchun  HU Ningjing  FU Yongtao  MA Zhibang 《中国科学D辑(英文版)》2006,49(4):375-383

1 Introduction The Okinawa Trough(OT) extends for ~1200 km between Taiwan and Kyushu, and is an incipient back-arc basin bounded by the Ryukyu Arc to the south and east, and by Diaoyudao Uplift Belt[1,2] (Tai- wan-Sinzi Belt[3]) to the north and west. Drastic faults and volcanic activities are the typical features in the OT. Generally, the OT is divided into three segments (north, middle and south) by the Tokara Strait and Kerama Gap[4]. The geological features, such as tec- tonics, m…  相似文献   

Optimization of Lead and Nickel Biosorption by Cystoseira trinodis (Brown Algae) Using Response Surface Methodology          下载免费PDF全文

Peyman Salehi  Fatemeh Mazraati Tajabadi  Habibollah Younesi  Yousef Dashti 《洁净——土壤、空气、水》2014,42(3):243-250

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In-stream water quality,invertebrate and fish community health across a gradient of dairy farming prevalence in a New Zealand river catchment     

《Limnologica》2016

Dairying is an intensive form of agriculture influencing stream ecosystems worldwide via increased levels of nutrients, deposited fine sediment and other contaminants. However, it is not fully understood how dairy farming affects food supply for stream fish. We investigated relationships between dairy farming prevalence in the catchments of nine tributaries of a New Zealand river (0% to 79% of the catchment area) and fish and invertebrate communities. Streams were sampled four times at monthly intervals for brown trout density, fitness/growth-related trout response variables, native fish density, invertebrate community metrics as well as physical and chemical water quality variables. Densities of both brown trout and native fish declined as dairying increased, with no trout found in streams where dairy farms covered more than 50% of the catchment area. Increasing dairy farming prevalence was also associated with higher in-stream levels of dissolved nutrients and deposited fine sediment. These findings suggest that increasing the extent of dairy farming in New Zealand based on practices at the time of sampling results in less abundant and diverse fish communities.  相似文献   

地震计自噪声的研究     

刘洋君  薛兵  朱小毅  林湛 《地震》2010,30(1):138-146

仪器的固有噪声水平是地震计的关键技术指标。 如何降低仪器的自噪声是地震计设计中需要解决的重要问题。 本文分析了产生地震计自噪声的两个主要噪声源: 布朗热噪声和电子噪声(1/f噪声), 以及它们对地震计传递函数的影响。 分析了三种地震计所记录的地震台台基噪声, 并且通过试验来检验仪器噪声对地震计观测数据的影响。  相似文献