检索结果-南通市图书馆

Chemical composition of sediments from the subducting Cocos Ridge segment at the Southern Central American subduction zone

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2022年第1期41卷 58-75页

作者： Renjie Zhao Quanshu Yan Haitao Zhang Yili Guan Xuefa shi College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

Subducted sediments play an important role in the magmatism at subduction zones and the formation of mantle heterogeneity,making them an important tracer for shallow crustal processes and deep mantle ***,ascertaining the chemical compositions of different subduction end-members is a prerequisite for using subducted sediments to trace key geological *** reports here the comprehensive major and trace element analyses of 52 samples from two holes(U1414 A and U1381 C)drilled on the subducting Cocos Ridge segment at the Southern Central American(SCA)subduction zone during Integrated Ocean Drilling Program(IODP)Expedition *** results show that the SCA subducting sediments contain 51%(wt%)Ca CO_(3),27%(wt%)terrigenous material,16%(wt%)opal,and 6%(wt%)mineral-bound H2 O+.Compared to the global trenches subducting sediment,the SCA subducting sediments are enriched in biogenic elements(Ba,Sr,and Ca),and depleted in high field strength elements(Nb,Ta,Zr,Hf,and Ti)and alkali elements(K,Rb,and Cs).Meanwhile,the sediments in this area were affected by the carbonate crash event,which could have been caused by a~800 m rise in the carbonate compensation depth at 11 Ma in the Guatemala *** reason for the sedimentary hiatus at Hole U1381 C may be the closure of the Panama Isthmus and the collision between the Cocos Ridge and the Middle America *** addition,the sediments from the subducting Cocos Ridge segment have influenced the petrogenesis of volcanic lavas erupted in the SCA.

关键词： subducting sediments IODP Expedition 344 geochemistry Southern Central American subduction zone

Petrochemical eigenvalues and diagrams for the identification of metamorphic rocks'protolith,taking the host rocks of Dashuigou tellurium deposit in China as an example

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2023年第1期42卷 103-124页

作者： Jianzhao Yin Shoupu Xiang Yuhong Chao Yuhan Yin Hongyun shi College of Earth Sciences Jilin University2199 Jianshe StreetChangchun 130061China Silvercorp Metals Inc Suite 601-Building 1China View Mansion#A2 East GongTi RoadChaoyang DistrictBeijing 100027China Engineering Geology Brigade of Jiangxi Bureau of Geology 658 Jiefangxilu RoadNanchang 330002Jiangxi ProvinceChina Xuchang Electrical Vocational College Xuchang 461000China Orient Resources Ltd 9280 Kirkmond CrescentRichmondB.C V7E 1M8Canada

The Dashuigou tellurium deposit is the world’s only known independent tellurium *** restoring metamorphic rocks’protolith,we seek to understand not only the development and evolution trajectory of the region but also the origin of the relevant *** there are many ways to restore metamorphic rocks’protolith,we take the host metamorphic rocks of Dashuigou tellurium deposit and leverage various petrochemical eigenvalues and related diagrams previously proposed to reveal the deposit’s host metamorphic rocks’*** petrochemical eigenvalues include molecular number,Niggli’s value,REE parity ratio,CaO/Al_(2)O_(3)ratio,Fe^(3+) /(Fe^(3+) -+Fe^(2+) )ratio,chondrite-normalized REE value,logarithmic REE value,various REE eigenvalues including scandium,Eu/Sm ratio,total REE amount,light and heavy REEs,δEu,Eu anomaly,Sm/Nd ratio,and silicon isotope δ^(30) SiNBS-29‰,*** petrochemical plots include ACMs,100 mg-c-(al+alk),SiO_(2)-(Na_(2)O+K_(2)O),(al+fm)-(c+alk)versus Si,FeO+Fe_(2)O^(3+) TiO)-Al_(2)O_(3)-MgO,c-mg,Al_(2)O_(3)-(Na_(2)O+K_(2)O),chondrite-normalized REE model,La/Yb-REE,and Sm/Nd ratio,*** the basis of these comprehensive analyses,the following conclusions are drawn,starting from the many mantle-derived types of basalt developed in the study area of different geological ages,combined with the previously published research results on the deposit s fluid inclusions and sulfur and lead *** deposit is formed by mantle degassing in the form of a mantle plume in the late Yanshanian *** degassed fluids are rich in nano-sc ale substances including Fe,Te,S,As,Bi,Au,Se,H_(2),CO_(2),N_(2),H_(2)O,and CH_(4),which are enriched by nano-effect,and then rise to a certain part of the crust in the form of mantle plume along the lithospheric fault to form the *** ultimate power for tellurium mineralization was from H_(2)flow with high energy,which was produced through radiation from the melted iron of the Earth’s outer *** H,flo

关键词： Petrochemical diagrams and eigenvalue Protolith Metamorphic rock Independent tellurium deposit Host rock The mantle plume

Characterization of multiple chemical components of GuiLingJi by UHPLC-MS and ^(1)H NMR analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2022年第3期12卷 460-469页

作者： Jingchao shi Xiaoxia Gao Airong Zhang Xuemei Qin Guanhua Du Modern Research Center for Traditional Chinese Medicine Shanxi UniversityTaiyuan030006China School of Traditional Chinese Materia Medica and Food Engineering Shanxi University of Chinese MedicineJinzhongShanxi030619China Shanxi Guangyuyuan Chinese Medicine Co. Ltd.JinzhongShanxi030800China Institute of Materia Medica Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing100050China

GuiLingJi(GLJ),a classic traditional Chinese medicine(TCM)formula,is composed of over 20 herbs,according to the Pharmacopeia of the People's Republic of *** to its various activities,GLJ has been used in clinical settings for more than 400 years in ***,the ambiguous chemical material basis limits the development of studies on the quality control and pharmacological mechanisms of ***,comprehensive characterization of the multiple chemical components of GLJ is of great significance for the modernization of this *** the great variety of herbs in GLJ,both UHPLCMS and ^(1)H NMR techniques were employed in this *** addition,solvent extraction with different polarities was used to eliminate signal interference and the concentration of trace components.A variety of MS analytic methods were also used,including implementation of a self-built compound database,diagnostic ion filtering,mass defect filtering,and Compound Discoverer 3.0 analysis *** on the above strategies,a total of 150 compounds were identified,including 5 amino acids,13 phenolic acids and glycosides,11 coumarins,72 flavones,20 triterpenoid and triterpenoid saponins,23 fatty acids,and 6 other ***,13 compounds were identified by ^(1)H NMR *** UHPLC-MS and ^(1)H NMR results supported and complemented each *** strategy provides a rapid approach to analyzing and identifying the chemical composition of Chinese herbal *** current study provides basis for further research on the quality control and pharmacological mechanism of GLJ.

关键词： GuiLingJi Chemical component UHPLC-MS ^(1)H NMR Traditional Chinese medicine

Integration of satellite remote sensing data in underground coal fire detection:A case study of the Fukang region,Xinjiang,China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2020年第1期14卷 1-12页

作者： shiyong YAN Ke shi Yi LI Jinglong LIU Hongfeng ZHAO Ministy of Natural Resource Key Lab of Land Environment and Disaster Monitoring China University of Mining and TechnologyXuzhou 221116China School of Environment Science and Spatial Informatics China University of Mining and TechnologyXuzhou 221116China Comprehensive Geological Exploration Team in Coal Geology Bureau of Xinjiang Uygur Autonomous Region Urumchi 830009China

Xinjiang in China is one of the areas worst affected by coal *** fires cannot only waste a large amount of natural resources and cause serious economic losses,but they also cause huge damage to the atmosphere,the soil,the surrounding geology,and the ***,there is an urgent need to effectively explore remote sensing based detection of coal fires for timely understanding of their latest development *** this study,in order to investigate the distribution of coal fires in an accurate and reliable manner,we exploited both Landsat-8 optical data and Sentinel-1A synthetic aperture radar(SAR)images,using the generalized single-channel algorithm and the InSAR time-series analysis approach,respectively,for coal fire detection in the southern part of the Fukang region of Xinjiang,*** generalized single-channel algorithm was used for land surface temperature information ***,the timeseries InSAR analysis technology was employed for estimating the surface micro deformation information,which was then used for building a band-pass *** suspected coal fire locations could then be established by a band-pass filtering operation on the obtained surface temperature ***,the locations of the suspected coal fires were validated by the use of field survey *** results indicate that the integration of thermal infrared remote sensing and radar interferometry technologies is an efficient investigation approach for coal fire detection in a large-scale region,which would provide the necessary spatial information support for the survey and control of coal fires.

关键词： land surface temperature generalized singlechannel algorithm surface deformation time-series InSAR analysis filtering operation coal fire detection

Review and prospect of soil compound erosion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Arid Land 2023年第9期15卷 1007-1022页

作者： YANG Wenqian ZHANG Gangfeng YANG Huimin LIN Degen shi Peijun State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China Academy of Disaster Reduction and Emergency Management Ministry of Emergency Management and Ministry of EducationBeijing Normal UniversityBeijing 100875China College of Land and Tourism Luoyang Normal UniversityLuoyang 471934China School of Business Wenzhou UniversityWenzhou 325035China Academy of Plateau Science and Sustainability Qinghai Normal UniversityXining 810016China

Soil erosion is one of the most serious environmental issues constraining the sustainable development of human society and *** compound erosion is the result of the alternation or interaction between two or more erosion *** recent years,fluctuations and extreme changes in climatic factors(air temperature,precipitation,wind speed,etc.)have led to an increase in the intensity and extent of compound erosion,which is increasingly considered in soil erosion ***,depending on the involvement of gravity,compound erosion process can be divided into compound erosion with and without *** systematically summarized the research on the mechanisms and processes of alternating or interacting soil erosion forces(wind,water,and freeze-thaw)considering different combinations,combed the characteristics of compound erosion in three typical regions,namely,high-elevation areas,high-latitude areas,and dry and wet transition regions,and reviewed soil compound erosion research methods,such as station observations,simulation experiments,prediction models,and artificial neural *** soil erosion model of wind,water,and freeze-thaw interaction is the most significant method for quantifying and predicting compound ***,it is proposed that there are several issues such as unclear internal mechanisms,lack of comprehensive prediction models,and insufficient scale conversion methods in soil compound erosion *** is also suggested that future soil compound erosion mechanism research should prioritize the coupling of compound erosion forces and climate change.

关键词： soil compound erosion soil erosion gravity erosion wind and water erosion freeze-thaw erosion

Refinement of primary Si in Cu-50Si alloys with novel Al-Zr-P master alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2013年第3期32卷 252-257页

作者： Min Zuo Zhong-shi Zhang Xin-Ying Teng Hao-Ran Geng Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials School of Materials Science and Engineering University of Jinan School of Physics and Technology University of Jinan

In this article, a novel Al-6Zr-2P master alloy with ZrP particles was successfully synthesized, and the refining performance of this novel master alloy for the primary Si in Cu-50Si alloys was also investigated. By means of the fracture plane observation, it is found that the ZrP phase would precipitate first in the solidification pro- cess, and then, the ZrAl3 phase grows around them. Fur- thermore, it is observed that the refining effect can be remarkably improved by changing the addition sequence of the raw materials. After the melting of commercial Cu, the 2.0 wt% Al-6Zr-2P master alloy and crystalline Si were added in sequence, and the mean size of the primary Si in Cu-50Si alloy can be significantly refined from 255.7 to 75.3 gm. Meanwhile, the refining mechanism was dis- cussed in detail.

关键词： Al-Zr-P master alloy Cu-Si alloy ZrP Microstructure Phase transformation

Metagenomic Profiling of Viruses Associated with Rhipicephalus microplus Ticks in Yunnan Province,China

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2021年第4期36卷 623-635页

作者： Junming shi Shu Shen Hui Wu Yunzhi Zhang Fei Deng State Key Laboratory of Virology and National Virus Resource Center Wuhan Institute of VirologyChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China Institute of Preventive Medicine School of Public HealthDali UniversityDali 671000China Xianning Center for Disease Control and Prevention Xinanning 437000China

Ticks are well known as vectors of many viruses which usually do great harm to human and animal *** Province,widely covered by flourishing vegetation and mainly relying on farming husbandry,is abundant with Rhipicephalus microplus ***,it is of great significance to characterize the viral profile present in *** parasitizing on cattle in Yunnan *** this study,a total of 7387 *** ticks were collected from cattle and buffalo in the northwest and southeast areas of Yunnan Province from 2015 to *** investigated the virome of *** using next-generation sequencing(NGS)and the prevalence of important identified viruses among tick groups by *** revealed the presence of diverse virus concerning chu-,rhabdo-,phlebo-,flavi-and parvo-viruses in *** viruses consist of single-stranded,circular and segmented sense RNAs,showing a greatly diversity in genomic ***,continuous epidemiological survey among ticks reveals broad prevalence of three viruses(Yunnan mivirus 1,Wuhan tick vrius 1 and YN tick-associated phlebovirus 1)and two possible prevalent viruses including a flavivirus-like segmented virus(Jingmen tick virus)and a bovine hokovirus 2 in *** investigation among cattle indicates that these identified viruses may be infectious to cattle and can elicit corresponding *** findings on ***-associated viral community will contribute to the prevention of viral disease and tracking the viral *** analysis is needed to better elucidate the pathogenicity and natural circulation of these viruses.

关键词： Viral profile R.microplus ticks China Diversity

Impact of flm thickness in laser‑induced periodic structures on amorphous Si flms

在线全文

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2023年第2期16卷 115-122页

作者： Liye Xu Jiao Geng Liping shi Weicheng Cui Min Qiu College of Optical Science and Engineering Zhejiang UniversityHangzhou 310058China Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province School of EngineeringWestlake UniversityHangzhou 310024China Key Laboratory of Coastal Environment and Resources of Zhejiang Province(KLaCER) School of EngineeringWestlake UniversityHangzhou 310024China Institute of Advanced Technology Westlake Institute for Advanced StudyHangzhou 310024China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China

We report self-organized periodic nanostructures on amorphous silicon thin flms by femtosecond laser-induced *** dependence of structural periodicity on the thickness of silicon flms and the substrate materials is *** results reveal that when silicon flm is 200 nm,the period of self-organized nanostructures is close to the laser wavelength and is insensitive to the *** contrast,when the silicon flm is 50 nm,the period of nanostructures is much shorter than the laser wavelength,and is dependent on the ***,we demonstrate that,for the thick silicon flms,quasi-cylindrical waves dominate the formation of periodic nanostructures,while for the thin silicon flms,the formation originates from slab waveguide ***-diference time-domain method-based numerical simulations support the experimental discoveries.

关键词： Laser-induced periodic surface structures(LIPSS) Ultrafast optoelectronics Laser nanofabrication Quasicylindrical waves

Ancient depletion signals in lherzolites from forearc region:Constraints from Lu-Hf isotope compositions

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2022年第1期13卷 62-75页

作者： Yang Xu Chuan-Zhou Liu Wei Lin Xue-Fa shi Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The sub-arc mantle that experienced hydrous melting is commonly characterized by refractory geochemical compositions. Nevertheless, minor lherzolites with fertile compositions have also been reported for mantle peridotites from subduction zone. The petrogenesis and mantle source of the lherzolites are still controversial. The New Caledonia ophiolite(Peridotite Nappe) has been regarded as an allochthonous body of forearc lithosphere. This is supported by refractory compositions of its dominant mantle rocks.A few isolated lherzolitic massifs have also been observed in the northern part of New *** lherzolites are compositionally similar to abyssal peridotites, with negligible subduction-related modification. Here, we present new comprehensive geochemical compositions, in particular highprecision Sr-Nd-Hf isotope data, for the lherzolites. The initial^(176) Hf/^(177) Hf ratios display moderate correlations with sensitive indicators for the extent of melting(i.e., olivine Fo, whole-rock Mg# and Yb contents in clinopyroxene) and whole-rock initial^(187) Os/^(188) Os ratios. Some samples have ancient radiogenic Hf isotopes and unradiogenic Os isotope compositions, implying the preservation of ancient depletion signals in the lherzolites. The Nd isotope compositions, together with trace elements and mineral micro-textures, suggest that the lherzolites have been overprinted by a recent melt-rock interaction event. The high equilibrium temperatures of the studied samples have been estimated by the twopyroxene REE thermometer, yielding temperatures of 1066–1315 ℃. The lherzolites have more depleted Nd-Hf isotope compositions and higher equilibrium temperatures than the New Caledonia *** indicates that the lherzolites may represent the residues of asthenosphere mantle trapped within the forearc region. Our studies on the New Caledonia lherzolites with ancient depletion signals suggest that ancient mantle domains in the convective mantle can be emplaced

关键词： New Caledonia ophiolite Forearc Lherzolites Sr-Nd-Hf isotopes Ancient melt depletion