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Classification of Sandstone-Related Uranium Deposits

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Journal of Earth Science 2022年第2期33卷 236-256页

作者： Michel Cuney Julien Mercadier Christophe Bonnetti Universitéde Lorraine GéoRessourcesCNRSCREGUNancy F54500France 2.State Key Laboratory of Nuclear Resources and EnvironmentEast China University of TechnologyNanchang 330013China

Sandstone type deposits are the most common type of uranium deposits in the world.A large variety of sub-types have been defined,based either on the morphology of the deposits(e.g.,tabular,roll front,etc),or on the sedimentological setting(e.g.,paleovalley,paleochannel,unconformity),or on tectonic or lithologic controls(e.g.,tectonolithologic,mafic dykes/sills),or still on a variety of others characteristics(phreatic oxidation type,interlayer permeable type,multi-element stratabound infiltrational,solution front limb deposit,humate type,etc.),reflecting the diversity of the characteristics of these deposits,but making it difficult to have a clear overview of these ***,uranium deposits occurring in the same sedimentological setting(e.g.,paleochannel),presenting similar morphologies(e.g.,tabular),may result from different genetic mechanisms and thus can be misleading for exploration *** aim of the present paper is to propose a new view on sandstone-related uranium deposits combining both genetic and descriptive *** dual view is indeed of primordial importance because all the critical characteristics of each deposit type,not limited to the morphology/geometry of the ore bodies and their relationships with depositional environments of the sandstone,have to be taken into account to propose a comprehensive classification of uranium *** this respect,several key ore-forming processes,like the physical-chemical characteristics of the mineralizing fluid,have to be used to integrate genetic aspects in the *** a succession of concentration steps,potentially temporally-disconnected,are involved in the genesis of some uranium mineralization,the classification here proposed will focus on the main mechanisms responsible for the formation and/or the location of ore *** objective of this paper is also to propose a robust and widely usable terminology to define and categorize sandstone uranium deposits,considering

关键词： sandstone uranium genetic classification redox control depositional environment fluids ore deposit geology

Analysis of environmental selection pressure of superoxide dismutase in deep-sea sea cucumber

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Journal of Oceanology and Limnology 2024年第3期42卷 893-904页

作者： Yanan LI Zongfu CHEN Haibin ZHANG Ruoyu LIU Shuichun CHEN Li LIN Guangzhou Key laboratory of Aquatic Animal Diseases and Waterfowl Breeding College of Animal Sciences and TechnologyZhongkai University of Agriculture and EngineeringGuangzhou 510222China Institute of Deep-sea Science and Engineering Chinese Academy of SciencesSanya 572000China College of Marine Science Fujian Agriculture and Forestry UniversityFuzhou 350002China Zhanjiang Tianli Sea Cucumber New Technology Development Co. Ltd.Zhanjiang 524000China

Manganese superoxide dismutase(MnSOD)is an antioxidant that exists in mitochondria and can effectively remove superoxide anions in *** a dark,high-pressure,and low-temperature deep-sea environment,MnSOD is essential for the survival of sea *** MnSODs were identified from the transcriptomes of deep and shallow-sea sea *** explore their environmental adaptation mechanism,we conducted environmental selection pressure analysis through the branching site model of PAML *** obtained night positive selection sites,and two of them were significant(97F→H,134K→V):97F→H located in a highly conservative characteristic sequence,and its polarity c hange might have a great impact on the function of MnSOD;134K→V had a change in piezophilic a bility,which might help MnSOD adapt to the environment of high hydrostatic pressure in the *** further study the effect of these two positive selection sites on MnSOD,we predicted the point mutations of F97H and K134V on shallow-sea sea cucumber by using MAESTROweb and *** show that 97F→H,134K→V might improve MnSOD’s efficiency of scavenging superoxide a nion and its ability to resist high hydrostatic pressure by moderately reducing its *** above results indicated that MnSODs of deep-sea sea cucumber adapted to deep-sea environments through their amino acid changes in polarity,piezophilic behavior,and local *** study revealed the correlation between MnSOD and extreme environment,and will help improve our understanding of the organism’s adaptation mechanisms in deep sea.

关键词： Holothuroidea environmental adaptation positive selection point mutation

Simulating the effect of wind erosion on aeolian desertification process of Horqin sandy land and its significance on material cycle:a wind tunnel study

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Research in Cold and Arid Regions 2022年第1期14卷 43-53页

作者： CaiXia Zhang JinChang Li Key laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China Shanxi laboratory for Yellow River Institute of Loess PlateauShanxi UniversityTaiyuanShanxi 030006China

Samples from the Horqin sandy land were exposed to a series of wind velocities,and sink particles were collected at the end of the diffusion section of a wind *** sizes of collected samples show great variation because of the granularity difference of the surface *** original samples show lower average content of SiO_(2) and higher average content of Al _(2)O_(3),Fe_(2)O_(3),MgO,CaO,Na_(2)O,and K_(2)O than collected *** with other dust source areas in China,the Horqin sandy land had higher content of Zr,Ba,SiO_(2),Al_(2)O_(3) and K_(2)*** with the average upper continental crust(UCC)composition,surface samples were rich in the content of Y,Zr,Nb,Ba,La,*** characteristics of fine grain components of the Horqin sandy land differ from those from other dust source regions,because fine-grained particles in the Horqin sandy land were mostly derived from various local deposits formed in its unique depositional environments influenced by several tectonic activities.

关键词： sink sand wind erosion aeolian process Horqin sandy land

Sulfuric acid leaching of high iron-bearing zinc calcine

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International Journal of Minerals,Metallurgy and materials 2017年第11期24卷 1211-1216页

作者： Jin-lin Yang Ji-guang Liu Han-xin Xiao Shao-jian Ma College of Resources Environment and Materials Guangxi University Nanning 530004 China Ministry-Province Jointly-Constructed Cultivation Base for State Key laboratory of Processing for Non-ferrous Metal and Featured materials Guangxi Zhuang Autonomous Region Guangxi University Nanning 530004 China

Sulfuric acid leaching of high iron-bearing zinc calcine was investigated to assess the effects of sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, and the stirring speed on the leaching rates of zinc and iron. The results showed that the sulfuric acid concentration, liquid-to-solid ratio, leaching time, and leaching temperature strongly influenced the leaching of zinc and iron, whereas stirring speed had little influence. Zinc was mainly leached and the leaching rate of iron was low when the sulfuric acid concentration was less than 100 g/L. At sulfuric acid concentrations higher than 100 g/L, the leaching rate of iron increased quickly with increasing sulfuric acid concentration. This behavior is attributed to iron-bearing minerals such as zinc ferrite in zinc calcine dissolving at high temperatures and high sulfuric acid concentrations but not at low temperatures and low sulfuric acid concentrations.

关键词： high iron-bearing zinc calcine sulfuric acid leaching zinc ferrite leaching rate

An overview of the environmental finance policies in China： retrofitting an integrated mechanism for environmental management

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Frontiers of environmental Science & Engineering 2014年第3期8卷 316-328页

作者： Wei LI Mengze HU State Key laboratory of Water environment Simulation School of Environment Beijing Normal University Beijing 100875 China

Considering the significant roles of the policies in developing environmental finance, an overview is conducted on the environmental finance policies （EFPs） in China. This paper analyzed the definition, scope, evolution and main instruments of EFPs. The implementation progress of financial activities on each instrument are investigated respectively. Then the experiences learned from and failures discovered in the development of the EFPs are discussed well recommendations for further improvement of the EFPs and their implementation are provided. Our study found that the EFPs have been established in China after a four-phase evolution since the early 1980s. The policies have played a critical role in leading to a rapid development in environmental finance by involving more financial instruments to accomplish the objective-led environmental plans. Driven by the policies, the new green credit （GC）, green security （GS）, and green insurance （GI） instruments have been phased in as supplements to the conventional command and control approaches to improve the environmental governance of financial activities and pollution sources. However, the market mechanism of financial institution is limited due to their defensive and incapable performance on implementation some of EFP instruments. To further strengthen the effectiveness of EFPs in facilitating environmental man- agement, recommendations are made mainly on the aspects including developing more specific policy guidelines, enhancing information sharing and disclosure, providing sufficient economic incentives, establishing environmental liabilities with financial activities, and involving issues related to climate change, and biodiversity and ecosystem service.

关键词： environmental finance policy integrated mechanism phased evolution implementation progress,financial institution environmental management

Spatial and vertical variations of perfluoroalkyl substances in sediments of the Haihe River,China

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Journal of environmental Sciences 2014年第8期26卷 1557-1566页

作者： Xiuli Zhao Xinghui Xia Shangwei Zhang Qiong Wu Xuejun Wang School of environment Beijing Normal University/State Key Laboratory of Water Environment Simulation College of Urban and environmental Sciences Peking University

The levels of six perfluoroalkyl substances（PFASs） in surface sediment and their vertical variations in dated sediment cores from the Haihe River were investigated; studied substances included perfluorooctanoic acid（PFOA）,perfluorononanoic acid（PFNA）,perfluorooctane sulfonate（PFOS）,perfluorodecanoic acid（PFDA）,perfluoroundecanoic acid（PFUnA）,and perfluorododecanoic acid（PFDoA）. Results showed that the total PFAS concentration in surface sediment ranged between 0.52 and 16.33 ng/g dry weight（dw） with an average of3.47 ng/g dw,with PFOS and PFOA as the dominant PFASs. In general,the PFAS concentrations in the mainstream increased from the upper to the lower reaches,except that a drop occurred downstream of the Erdao dam. Although the PFASs in the sediment cores did not show a clear decreasing or increasing trend with depth,the three cores had a similar vertical *** PFAS levels were relatively low in the surface sediment,and reached the first high point at8–20 cm as a result of the wide use of PFASs from 1990 to 2000. After that the PFAS levels decreased,and then increased to a second high point at about 40–48 cm,which might be caused by the leaching of PFASs in sediment. Because PFASs have hydrophilic groups and relatively high solubility,the PFASs will transfer from the upper to lower layers of sediment when water infiltration occurs,leading to the fluctuation of PFAS levels in sediment cores. This study suggests that both the temporal variation of sources and transfer processes of PFASs in sediments are important factors influencing the vertical variation of PFASs in sediment cores.

关键词： Perfluoroalkyl substances(PFASs) Sediment core Sediment quality Haihe River

Dynamics of bubble-shaped Bose-Einstein condensates on two-dimensional cross-section in micro-gravity environment

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中国物理B:英文版 2023年第9期32卷 200-205页

作者：张铁夫李成蹊刘伍明 Beijing National laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Songshan Lake materials laboratory Dongguan 523808China

We investigated the dynamic evolution and interference phenomena of bubble-shaped Bose-Einstein condensates achievable in a micro-gravity *** numerical solutions of the Gross-Pitaevskii equation describing the dynamic evolution of the bubble-shaped Bose-Einstein condensates,we plotted the evolution of the wave function density distribution on its two-dimensional(2D)cross-section and analysed the resulting *** found that changes in the strength of atomic interactions and initial momentum can affect the dynamic evolution of the bubble-shaped Bose-Einstein condensates and their interference ***,we have observed that when the initial momentum is sufficiently high,the thickness of the bubble-shaped Bose-Einstein condensate undergoes a counterintuitive thinning,which is a counterintuitive result that requires further *** findings are poised to advance our comprehension of the physical essence of bubble-shaped Bose-Einstein condensates and to facilitate the development of relevant experiments in microgravity environments.

关键词： boson systems ultracold gases dynamic properties of condensates

Decay stages and meteorological factors affect microbial community during leaf litter in situ decomposition

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Soil Ecology Letters 2023年第3期5卷 61-73页

作者： Haixin Zhang Yimei Huang Shaoshan An Quanchao Zeng Baorong Wang Xuejuan Bai Qian Huang Key laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of AgricultureCollege of Natural Resources and EnvironmentNorthwest A&F UniversityYangling 712100China State Key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling712100China Huazhong Agricultural University College of Resources&EnvironmentWuhan 430070China State Key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences andMinistry of Water ResourcesYangling 712100China

Litter microorganisms play a crucial role in the biological decomposition in forest ecosystems;however,the coupling effect of meteorological and substrate changes on it during the different stages of leaf decomposition in situ remains ***,according to meteorological factors dynamics,a one-year field litter of Quercus wutaishanica in situ decomposition experiment was designed for four decay stages in a warm temperate *** community composition was characterized using Illumina sequencing of fungal ITS and bacterial 16S ***(6.6)and fungal(3.6)Shannon indexes were the largest after 125 days’litter decomposition(October).The relative abundance of Acidobacteria after 342 days and Bacteroidetes after 125 days were 3 and 24 times higher than after 31 days,*** non-dominant species(bacteria:Firmicutes,Planctomycotes,and Verrucomicrobia;fungi:Chytridiomycota and Glomeromomycota)may be absent or present at different decomposition stages due to litter properties or meteorological *** and aerobic-chemoheterotrophy were the dominant bacterial functional groups,and the dominant fungal functional groups were saprotrophs,pathotrophs,and *** and relative humidity significantly affected ***,sunlight intensity,and net radiation significantly affected ***,among the relative contributions of changes in bacterial and fungal community structure,leaf litter properties alone explained the variation of 5.51%and 10.63%.Microbial diversity and decay stage directly affected the litter mass-loss rate,with meteorological factors(precipitation,relative humidity,air temperature,and sunlight intensity)being *** findings highlight the importance of microbial diversity for leaf litter decomposition and the influence of meteorological factors.

关键词： leaf litter decomposition microbial community composition meteorological factors Loess Plateau Quercus wutaishanica

Development and optimization of object detection technology in pavement engineering: A literature review

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Journal of Road Engineering 2024年第2期4卷 163-188页

作者： Hui Yao Yaning Fan Yanhao Liu Dandan Cao Ning Chen Tiancheng Luo Jingyu Yang Xueyi Hu Jie Ji Zhanping You Beijing Key laboratory of Transportation Engineering Faculty of ArchitectureCivil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China School of Civil and Transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China Department of Civil and environmental Engineering Michigan Technological UniversityHoughtonMI 49931USA

Due to the rapid advancement of the transportation industry and the continual increase in pavement infrastructure,it is difficult to keep up with the huge road maintenance task by relying only on the traditional manual detection *** pavement detection technology with deep learning techniques is available for the research and industry areas by the gradual development of computer vision *** to the different characteristics of pavement distress and the uncertainty of the external environment,this kind of object detection technology for distress classification and location still faces great *** paper discusses the development of object detection technology and analyzes classical convolutional neural network(CNN)*** addition to the one-stage and two-stage object detection frameworks,object detection without anchor frames is introduced,which is divided according to whether the anchor box is used or *** paper also introduces attention mechanisms based on convolutional neural networks and emphasizes the performance of these mechanisms to further enhance the accuracy of object *** network architecture is introduced for mobile and industrial *** stereo cameras and sensors are rapidly developed,a detailed summary of three-dimensional object detection algorithms is also *** reviewing the history of the development of object detection,the scope of this review is not only limited to the area of pavement crack detection but also guidance for researchers in related fields is shared.

关键词： Pavement engineering Object detection Lightweight network Attention mechanism Convolutional neural network