检索结果-南通市图书馆

Origin of a giant fuzzy reflection zone and its implication for natural gas exploration in the southwestern Qiongdongnan Basin of the South China Sea

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 Oceanology and Limnology 2023年第2期41卷 710-728页

作者： Junhui yu pin YAN Yanlin WANG Yan QIU Guanghong TU Changliang CHEN Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyInnovation Academy of South China Sea Ecology and Environmental EngineeringChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China Key Laboratory of Marine Mineral Resources Guangzhou Marine Geological SurveyChina Geological SurveyMinistry of Natural ResourcesGuangzhou 511458China University of Chinese Academy of Sciences Beijing 100049China

The southwestern depression of the Qiongdongnan Basin(QDNB)hosts thick Cenozoic sediments and awaits major hydrocarbon discovery.Multichannel seismic(MCS)profile CFT2011 across the southwestern QDNB reveals a~60-km-wide fuzzy reflection zone(FRZ)within the sediments,but its origin and distribution remain unclear.Here ocean bottom seismometer(OBS)data of Line CFT2011 are processed with focus on the velocity structures by traveltime tomography inversion and analyzed together with the coincident and adjacent MCS profiles.The OBS velocity results show that the giant FRZ features lower velocity with difference up to 1.5 km/s and smaller vertical velocity gradient than the surrounding sedimentary sequences at the same depth,likely resulting from enhanced fluid infilling.The MCS profile exhibits that the giant FRZ is about 3-9-km thick and extends from the Paleogene strata rich in organic matters upward to the lower Pleistocene sediments.Within the shallow overlying sediments,multiple bright spots with reverse polarity are imaged and their reflection amplitudes increase with offset,consistent with the features of gas-charged sediments.They are probably shallow gas reservoirs with gases sourced from the deep FRZ.Therefore,the FRZ is proposed to be a giant gas-charged zone,which probably contains lots of hydrocarbon gases migrated vertically from the deep Paleogene source rocks through the boundary faults of the depressions and the minor fractures generated under overpressure.This FRZ is also imaged on the adjacent MCS profiles MCS-L1 and MCS-L2 with the width of about 40 km and 68 km,respectively.It is roughly estimated to cover an area of~1900 km2 and host a volume of~11400 km3 assuming an average thickness of 6 km,implying huge natural gas potential in the sedimentary depression of the southwestern QDNB of the South China Sea.

关键词： southwestern Qiongdongnan Basin fuzzy reflection zone low velocity gas charging natural gas potential

Benchmark solutions of large-strain cavity contraction for deep tunnel convergence in geomaterials

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 596-607页

作者： pin-Qiang Mo Yong Fang Hai-Sui yu State Key Laboratory for Geomechanics and Deep Underground Engineering School of Mechanics and Civil EngineeringChina University of Mining and TechnologyXuzhou221116China Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu610031China School of Civil Engineering University of LeedsLeedsLS29JTUK

To provide precise prediction of tunnelling-induced deformation of the surrounding geomaterials,a framework for derivation of rigorous large-strain solutions of unified spherical and cylindrical cavity contraction is presented for description of confinement-convergence responses for deep tunnels in geomaterials.Considering the tunnelling-induced large deformation,logarithmic strains are adopted for cavity contraction analyses in linearly elastic,non-associated Mohr-Coulomb,and brittle Hoek-Brown media.Compared with approximate solutions,the approximation error indicates the importance of release of small-strain restrictions for estimating tunnel convergence profiles,especially in terms of the scenarios with high stress condition and stiffness degradation under large deformation.The ground reaction curve is therefore predicted to describe the volume loss and stress relaxation around the tunnel walls.The stiffness of circular lining is calculated from the geometry and equivalent modulus of the supporting structure,and a lining installation factor is thus introduced to indicate the time of lining installation based on the prediction of spherical cavity contraction around the tunnel opening face.This study also provides a general approach for solutions using other sophisticated geomaterial models,and serves as benchmarks for analytical developments in consideration of nonlinear large-deformation behaviour and for numerical analyses of underground excavation.

关键词： Convergence-confinement method(CCM) Cavity contraction analysis Tunnel convergence

A review of aerial manipulation of small-scale rotorcraft unmanned robotic systems

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第1期32卷 200-214页

作者： Xilun DING pin GUO Kun XU yushu yu Robotics Institute Beihang University Department of Mechanics and Maritime Sciences Chalmers University of Technology

Small-scale rotorcraft unmanned robotic systems(SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years(2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem,trends, and challenges are described from three aspects. Conclusions of the paper are presented,and the future of SRURSs is discussed to enable further research interests.

关键词： Aerial manipulation Mechanical structure design Modeling and control Research groups Small-scale rotorcraft unmanned aerial systems Trends and challenges

Effect of cyclic quenching treatment on microstructural evolution and properties of ductile cast iron

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2023年第1期30卷 126-136页

作者： Jiao-jiao Bai Feng yu Cun-yu Wang Hui Wang Yang Xu Xing-pin Chen Wen-quan Cao College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Special Steel Institute Central Iron and Steel Research Institute(CISRI)Beijing 100081China College of Materials Science and Engineering Xi’an University of TechnologyXi’an 710000ShaanxiChina

Due to the coarse grain microstructure and low hardness of ductile cast iron(DCI),this material is unable to meet the performance requirements of bearing structural materials.To obtain ultra-fine-grained and ultra-hardened DCI,the influence of a cyclic quenching treatment on the evolution process and properties of DCI after three cycles of quenching at 860℃ for 30 min was investigated through morphology and grain-size characterization,X-ray diffraction analysis,and mechanical-property determination of DCI.It was found that the microstructure and performance depended strongly on the process of the cyclic quenching.With an increasing number of cycles,the grain size of austenite was significantly refined from 41.2 to 12.3μm,and the length and width of lath/plate martensite,as well as the lath and twins,are decreased.In the meantime,the morphology of retained austenite changed from blocky to granular,together with the stability increased.The experimental sample obtained a performance with a hardness higher than 60 HRC after cyclic quenching treatment due to the refined grain size and increased dislocation density.

关键词： Ductile cast iron Cyclic quenching Grain size Microstructure Hardness

Produced-water treatment: Application and research of combined fiber coalescence technique in offshore oilfield

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

Petroleum Science 2023年第1期20卷 569-576页

作者： pin-Yi Dai Yi-Qian Liu Hao Lu yu-Dong Li Qiang Yang School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai200237China

When the process of extraction of oil from an offshore oilfield enters the advanced stages,the water content in the extracted fluid can be above 90%.The water quality is complex with many types of pollutants and highly emulsified water.Therefore,a key consideration in the production process of offshore oilfields is the efficient and economical treatment of the oil-containing produced water to make it suitable for discharge and recover oil pollutants.In this study,we developed a hydrophilic and hydrophobic combined fiber coalescence separator with composite fiber shapes using fiber induction and X/Uweaving.The separator is designed based on experimental observations of the mechanism of structure coalescence in the physical oil removal method.A pilot test was performed on an oil exploration platform in the Bohai Sea.At the designed flow rate,the separator reduced the total concentration of petroleum in the produced water from 2000 to 3000 mg/L to below 60 mg/L,with an average oil removal efficiency of 98.24%.Furthermore,it effectively reduced the number of organic compounds present in the water from 120 to 17 and removed 70% of the SS.The test results show that the proposed device can be used fr produced-water treatment on offshore platforms.

关键词： Combined fiber coalescence Production water Oil-water separation X/U weaving

Microarray microRNA profiling of urinary exosomes in a 5XFAD mouse model of Alzheimer’s disease

在线全文

学校读者我要写书评

暂无评论

Animal Models and Experimental Medicine 2021年第3期4卷 233-242页

作者： Zhiqi Song Yajin Qu Yanfeng Xu Ling Zhang Li Zhou yunlin Han Wenjie Zhao Pin Yu yu Zhang Xianglei Li Chuan Qin Key Laboratory of Human Disease Comparative Medicine Chinese Ministry of HealthBeijing Key Laboratory for Animal Models of Emerging and Remerging Infectious DiseasesInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences and Comparative Medicine CenterPeking Union Medical CollegeBeijingChina

Background:Alzheimer's disease(AD)is an incurable and irreversible neurodegen-erative disease,without a clear pathogenesis.Therefore,identification of candidates before amyloid-βplaque(Aβ)deposition proceeds is of major significance for earlier intervention in AD.Methods:To explore the potential noninvasive earlier biomarkers of AD in a 5XFAD mouse model,microRNAs(miRNAs)from urinary exosomes in 1-month-old pre-Aβaccumulation 5XFAD mice models and their littermate controls were profiled by mi-croarray analysis.The differentially expressed miRNAs were further analyzed via droplet digital PCR(ddPCR).Results:Microarray analysis demonstrated that 48 differentially expressed miRNAs(18 upregulated and 30 downregulated),of which six miRNAs-miR-196b-5p,miR-339-3p,miR-34a-5p,miR-376b-3p,miR-677-5p,and miR-721-were predicted to display gene targets and important signaling pathways closely associated with AD pathogenesis and verified by ddPCR.Conclusions:Urinary exosomal miRNAs showing differences in expression prior to Aβ-plaque deposition were identified.These exosomal miRNAs represent potential noninvasive biomarkers that may be used to prevent AD in clinical applications.

关键词： 5XFAD mouse model Alzheimer's disease biomarkers microarray miRNA urinary exosome

Discovery of pockmarks in the Zengmu Basin,southern South China Sea and the implication

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2023年第2期41卷 757-768页

作者： Yanlin WANG Guanghong TU Junhui yu pin YAN Yongbin JIN Changliang CHEN Jie LIU Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyInnovation Academy of South China Sea Ecology and Environmental EngineeringChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Guangzhou Marine Geological Survey China Geological SurveyMinistry of Natural ResourcesGuangzhou 511458China University of Chinese Academy of Sciences Beijing 100049China

The Zengmu Basin located in the shallow water area of the southern South China Sea,is rich in oil and gas resources,within which faults and mud-diapir are developed,but it is unknown whether oil and gas migrate to the seafloor surface.The newly collected multibeam data across the Zengmu Basin reveal a large number of depressions,with depths of 2-4 m,widths of several tens of meters,large distribution range of 1.8-8 km along survey line,up to~50 km,and their backscatter intensity(-26 dB)is much greater than that of the surrounding area(-38 dB).Combined with the developed mud-diapir and fracture structures,and abundant oil and gas resources within this basin,these depressions are presumed to be pockmarks.Furthermore,more than 110 mono-sized small circular pockmarks,with a depth of less than 1 m and a width of 5 m,are observed in an area of less than 0.03 km2,which are not obliterated by sediment infilling with high sedimentation rate,implying an existence of unit-pockmarks that are or recently were active.In addition,seismic profiles across the Zengmu Basin show characterization of upward migration of hydrocarbons,expressed as mud-diapir structures,bright spots in the shallow formation with characteristics of“low frequency increase and high frequency attenuation”.The subbottom profiles show the mud-diapir structures,as well as the gas-bearing blank zones beneath the seafloor.These features suggest large gas leaking and occurrence of large amounts of carbonate nodules on the seafloor.This indicates the complex and variable substrate type in the Zengmu Basin,while the area was once thought to be mainly silty sand and find sand.This is the first report on the discovery of pockmarks in the Zengmu Basin;it will provide basic information for submarine stability and marine engineering in China’s maritime boundaries.

关键词： South China Sea Zengmu Basin dense pockmarks gas leaking substrate type

Self-assembly of Au/MoS_(2) quantum dots core-satellite hybrid as efficient electrocatalyst for hydrogen production

在线全文

学校读者我要写书评

暂无评论

Tungsten 2020年第2期2卷 194-202页

作者： Xue‑ping yu Chan Yang pin Song Juan Peng College of Chemistry and Chemical Engineering Ningxia UniversityYinchuan 750021China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore

Ultra-small MoS_(2) quantum dots(QDs)with an average size of 2.48 nm coated on Au nanoparticles with a core-satellite structure(Au/MoS_(2) QDs)are successfully prepared by a self-assembly strategy through the strong bonding between Au and S.Benefited from the unique structure,the Au/MoS_(2) QDs hybrid exhibits outstanding electrocatalytic performance toward hydrogen evolution reaction(HER).The Au/MoS_(2) QDs hybrid needs overpotentials of 112,146,and 206 mV to approach current densities of 10,20,and 50 mA·cm^(−2) in 0.5 mol·L^(−1) H_(2)SO_(4)(pH=0.3),respectively.And a low Tafel slope(83 mV·dec^(−1))is obtained.The catalyst also displays satisfactory stability and durability,indicating a negligible current density loss after 20 h of electrolysis.The high hydrogen generation activities and stability are attributed to the great number of active sites,high conductivity and synergistic effects between gold nanoparticles(Au NPs)and MoS_(2) QDs.Last but not least,this strategy opens up a favorable way to combine MoS_(2) QDs with other metals.

关键词： MoS_(2)QDs Gold nanoparticles Synergistic effect Hydrogen evolution reaction

Impact of Acupuncture Therapy in Postoperative Aortic Dissection Patients with Cerebral Infarction:A Case Study

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

Chinese Journal of Integrative Medicine 2017年第1期23卷 76-79页

作者： HSUEH Tun-pin HUNG yu-Chiang HU Wen-Long Department of Chinese Medicine Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of MedicineKaohsiungTaiwan 000800China Kaohsiung Medical University College of Medicine KaohsiungTaiwan 000800China Fooyin University College of Nursing Kaohsiunch Taiwan 000800China

Aortic dissection is a life-threatening disease that can produce a variety of symptoms and complications. Patients at high risk for mortality, such as individuals with aortic regurgitation, cardiac tamponade, or myocardial infarction, should be treated by surgery as soon as possible, especially in cases with acute ascending aortic dissections （Stanford type A）. However, patients with aortic dissection may suffer adverse outcomes that lead to mortality and morbidity, such as stoke, re-dissection, myocardial infarction, and heart failure. Patients with surgically treated acute type A aortic dissection show an 18.2% likelihood of stroke in early morbidity.

关键词： Impact of Acupuncture Therapy in Postoperative Aortic Dissection Patients with Cerebral Infarction GCS MCA than