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Distribution and influencing factors of acoustic characteristics of seafloor sediment in the Sunda Shelf

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Journal of Oceanology and limnology 2024年第5期42卷 1486-1492页

作者： Zhengyu HOU Danling TANG Jianguo liU {3. li peng XIAO School of Ocean Engineering and Technology Sun Yat-sen University&Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519000China Key laboratory of Comprehensive Observation of Polar Environment(Sun Yat-sen University) Ministry of EducationZhuhai 519082China Southern Marine Science and Engineering Guangdong laboratory(Guangzhou)&South{2. Sea {3. of Oceanology Chinese Academy of SciencesGuangzhou 511458China

To understand the acoustic and physical properties of piston core samples collected from the Sunda continental shelf and analyze their distribution patterns,the samples were analyzed in laboratory,from which three provinces were divided in sound speed,sound speed ratio,porosity,wet bulk density,and maximum shear ***Ⅰhad lower sound speed and sound speed ratio(her sound speed and sound speed ratio(>1.04),low porosity,and high wet bulk ***Ⅲhad the lowest sound speed and sound speed ratio(0.99),highest porosity(81%),and lowest wet bulk density(1.3. g/cm^(3.).The distribution pattern indicates that sediment movement,sediment source,topography,and hydrodynamic conditions influenced the distribution of acoustic and physical ***,we investigated the relationship of the maximum shear strength to the porosity and wet bulk density,and found that the maximum shear strength was proportional to both the porosity and wet bulk *** finding has significant implications for ocean engineering applications.

关键词： seafloor sediment acoustic property Sunda Shelf

Provenance of colorless and brown volcanic glass in late Pleistocene tephra layers in the Western Philippine Sea

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Journal of Oceanology and limnology 2024年第5期42卷 1438-1449页

作者： Fuqing JIANG Zhishun ZHANG zhaohui ZHANG Guoliang ZHANG {2. HUANG Xiaojing ZHOU Zhifang XIONG Congying li Tiegang li Key laboratory of Ocean Observation and Forecasting and Key laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China laboratory for Marine Geology Qingdao Marine Science and Technology CenterQingdao 266237China University of chinese Academy of sciences Beijing 100049China institute of Marine Chemistry and Environment Ocean CollegeZhejiang UniversityZhoushan 316021China College of Marine Technology and Environment Dalian Ocean UniversityDalian 116023China Key laboratory of Marine Sedimentology and Environmental Geology First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China

Tephra layers in the western Philippine Sea,characterized by abundant volcanic glass shards,may provide crucial evidence on the eruption history of volcanoes and tectonic evolution of the western Pacific.A 2.0-ka sediment core from the Benham Rise in the western Philippine Sea offers new insights into the provenance of four intercalated tephra layers(T1–T4,in chronological order)containing either colorless or brown glass *** to primitive mantle,all glass shards are enriched in large-ion lithophile elements,such as Rb,Cs,and Pb,and depleted in high field-strength elements,such as Th,Nb,and Ta,indicating a subduction-related *** colorless glass shards are characterized by high SiO_(2.(>78%)and light rare earth element(LREE)contents as well as high La/Sm ratios(>9),low FeO and MgO contents(100),pointing to a rhyolitic composition and a medium-K calc-alkaline serial *** contrast,the brown glass shards are characterized by lower SiO_(2.(3.)and LREE contents,higher FeO,MgO,and CaO contents,lower La/Sm(line andesite *** glass shards from layers T3.152.ka)and T4(172.ka)were correlated with volcanic deposits from the Taal and Laguna Caldera in the Maccolod Corridor,respectively,while the colorless glass shards from layers T1(3..5 ka)and T2.61.2.ka)were likely sourced from the Irosin Caldera in the Bicol *** the provenance of late Pleistocene tephra layers in the western Philippine Sea is helpful to complement a Philippine volcanic history and establish a regional tephrochronostratigraphy.

关键词： volcanic glass provenance chemical composition Philippine Sea late Pleistocene

Neomicrocoleus ***.(Microcoleaceae,Oscillatoriales),a novel cyanobacterial genus from benthic mats in a water channel

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Journal of Oceanology and limnology 2024年第1期42卷 263-276页

作者： Ruozhen GENG Zhongshi he Kaihui GAO {2. XIAO he ZHANG Si CheN Hua li Gongliang YU Renhui li College of life and Environmental sciences Wenzhou UniversityWenzhou 325035China Key laboratory of Algal Biology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China University of chinese Academy of sciences Beijing 100049China Hubei Institution of Land Surveying and Mapping Wuhan 430072China

A new filamentous cyanobacterial strain(CHAB 412.)was successfully isolated from the algal mat during the field investigation of the open channel from Luanhe River to Tianjin,*** polyphasic approach combining morphological,ultrastructural,ecological,and molecular features was used to characterize this studied *** strain is morphologically similar to the Microcoleus-like cyanobacterial taxa under light microscopy,and the radial arrangement of thylakoids is also consistent with that of Microcoleus-like *** phylogenetic position of CHAB 412. based on 16S rRNA gene sequences,is shown to be clearly clustered into an independent clade with the newly established genus *** maximum similarity of 16S r RNA gene of the studied strain with other existing related cyanobacterial taxa is 93.97%,and the ITS secondary structures is also obviously different from other members of *** on all the above evidence,we proposed the establishment of this novel cyanobacterial genus as Neomicrocoleus,with its type species,Neomicrocoleus tianjinensis.

关键词： Neomicrocoleus tianjinensis morphology 16S rRNA taxonomy polyphasic approach

In-situ construction of abundant active centers on hierarchically porous carbon electrode toward high-performance phosphate electrosorption: Synergistic effect of electric field and capture sites

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Green Energy & Environment 2024年第1期9卷 126-137页

作者： peng Zhang Fukuan li Mingming {2. Silu Huo Xueli Zhang Benqiang Cen Dezhi Fang Kexun li Hao Wang College of Environmental Science and Engineering Nankai UniversityTianjin300350China MOE Key laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlTianjin Key Laboratory of Environmental Technology for Complex Trans-Media PollutionNankai UniversityTianjin300350China State Key laboratory of Simulation and Regulation of Water Cycles in River Basins China Institute of Water Resources and Hydropower ResearchBeijing100038China

Phosphate removal is crucial for eutrophication control and water quality ***-assisted adsorption,an eco-friendly elec-trosorption process,exhibited a promising potential for wastewater ***,there are few works focused on phosphate electro-sorption,and reported electrodes cannot attach satisfactory removal capacities and ***,electro-assisted adsorption of phosphate via in-situ construction of La active centers on hierarchically porous carbon(LaPC)has been originally *** resulted LaPC composite not only possessed a hierarchically porous structure with uniformly dispersed La active sites,but also provided good conductivity for interfacial electron *** LaPC electrode achieved an ultrahigh phosphate electrosorption capability of 46{3.01 mg g^(-1) at 1 V,outperforming most existing *** superior phosphate removal performance originates from abundant active centers formed by the coupling of electricﬁeld and capture ***,the stability and selectivity toward phosphate capture were maintained well even under comprehensive ***,a series of kinetics and isotherms models were employed to validate the electrosorption *** work demonstrates a deep understanding and promotes a new level of phosphate electrosorption.

关键词： Electro-assisted adsorption Electrosorption Phosphate removal Active centers MOF-derived carbon

Optimal Design of the Modular Joint Drive Train for Enhancing Cobot Load Capacity and Dynamic Performance

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chinese Journal of Mechanical Engineering 2024年第3期37卷 26-40页

作者： peng li Z{2.nguo Nie Zihao li Xinjun liu Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China State Key laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control Tsinghua UniversityBeijing 100084China

Automation advancements prompts the extensive integration of collaborative robot(cobot)across a range of *** to the commonly used design approach of increasing the payload-to-weight ratio of cobot to enhance load capacity,equal attention should be paid to the dynamic response characteristics of cobot during the design process to make the cobot more *** this paper,a new method for designing the drive train parameters of cobot is ***,based on the analysis of factors influencing the load capacity and dynamic response characteristics,design criteria for both aspects are established for cobot with all optimization design criteria normalized within the design ***,with the cobot in the horizontal pose,the motor design scheme is discretized and it takes the joint motor diameter and gearbox speed ratio as optimization design ***,all the discrete values of the optimization objectives are obtained through the enumeration method and the Pareto front is used to select the optimal solution through multi-objective *** on the cobot design method proposed in this paper,a six-axis cobot is designed and compared with the commercial *** result shows that the load capacity of the designed cobot in this paper reaches 8.4 kg,surpassing the 5 kg load capacity commercial cobot which is used as a *** minimum resonance frequency of the joints is 42.70 Hz.

关键词： Multi-objective optimization Modular joint drive train design Load capacity Dynamic response performance

Gravitational waves and primordial black hole productions from gluodynamics by holography

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Science china(Physics,Mechanics & Astronomy) 2024年第4期67卷 31-42页

作者： Song he li li Zhibin li Shao-Jiang Wang Center for Theoretical Physics and College of Physics Jilin UniversityChangchun 130012China Max Planck institute for Gravitational Physics(Albert Einstein institute) Golm 14476Germany CAS Key laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Understanding the nature of quantum chromodynamics(QCD)matter is important but challenging due to the presence of nonperturbative dynamics under extreme *** construct a holographic model describing the gluon sector of QCD at finite temperatures in the non-perturbative *** equation of state as a function of temperature is in good accordance with the lattice QCD ***,the Polyakov loop and the gluon condensation,which are proper order parameters to capture the deconfinement phase transition,also agree quantitatively well with the lattice QCD *** obtain a strong first-order confinement/deconfinement phase transition at Tc=2.6.5 Me V that is consistent with the lattice QCD *** on our model for a pure gluon hidden sector,we compute the stochastic gravitational waves and primordial black hole(PBH)productions from this confinement/deconfinement phase transition in the early *** resulting stochastic gravitational-wave backgrounds are found to be within detectabi{12.ty in the International Pulsar Timing Array and Square Kilometre Array in the near future when the associated productions of PBHs saturate the current observational bounds on the PBH abundances from the {12.GO-Virgo-Collaboration O3.data.

关键词： AdS/QCD confinement/deconfinement phase transition gravitational wave primordial black hole

Differences in and factors controlling organic matter enrichment in the Ziliujing Formation shale in the Sichuan Basin

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Petroleum Science 2024年第1期21卷 77-86页

作者： peng li Zhong-Bao liu {3. Bi Tao Jiang Rui-Kang Bian peng-Wei Wang Xiao-Yu Shang State Key laboratory of Shale Oil and Gas Enrichment Mechanisms and Efficient Development Beijing102206China Key laboratory of Shale Oil/Gas Exploration and Production Technology SINOPECBeijing102206China Petroleum Exploration and Production Research institute SINOPECBeijing102206China Research institute of Petroleum Exploration and Development PetroChinaBeijing100083China chinese Academy of Geological sciences Beijing100037China No.4 Oil Production Plant in Daqing Oilfield Co Ltd. Daqing163511HeilongjiangChina

Lacustrine shale oil and gas are important fields for unconventional exploration and development in china,and organic-rich shale deposition lays down the critical foundation for hydrocarbon *** are two sets of shale,the Dongyuemiao and Da’anzhai Members,in the Ziliujing Formation in the Sichuan *** identify the differential enrichment characteristics of organic matter and clarify its controlling factors,geochemical analyses of organic and inorganic geochemical analyses were *** results showed that the total organic carbon content of the Dongyuemiao shale(1.3.%)is slightly higher than that of the Da’anzhai shale(0.95%).The enrichment of organic matter in the two shales resulted from the comprehensive controls of paleoproductivity,paleoenvironment,and terrigenous input,but different factors have different *** addition,driven by climate,the change in the sulfate concentration in the bottom water further led to the different intensities of bacterial sulfate reduction in early *** made a great difference regarding organic matter accumulation in the two *** general,climate may have played a dominant role in organic matter enrichment in the two sets of shale.

关键词： Lacustrine shale Ziliujing Formation Sichuan Basin Enrichment mechanism of organic matter

Co-aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

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Science china Chemistry 2024年第3期67卷 1017-1027页

作者： Bei liu Fan Wang Xiaomeng Dou pengfei li Hongwei Xiang Yong Yang peng he State Key laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Department of Chemistry Tsinghua UniversityBeijing 100084China national Energy R&D Center for Coal to liquid Fuels Synfuels China Technology Co.Ltd.Beijing 101407China University of chinese Academy of sciences Beijing 101408China Leibniz-Institut für Katalyse e.V.an der Universitat Rostock Rostock 18059Germany

The co-aromatization of methane with higher hydrocarbons represents a promising route to valorize methane, an abundant but underexploited carbon resource. In this study, we elucidate a novel approach to enhance the catalytic co-aromatization of hexane and methane by confining Pt within zeolite catalysts and modulating its electron density. Our findings show that encapsulating Pt within MFI structure is pivotal for activating the feedstock and fostering the formation of aromatic products. Interaction between K atoms and the silanol nest forms siloxy groups which are critical for the stabilization of Pt species. Tuning the K content in PtSn@MFI catalysts adeptly alters the electronic configuration of Pt clusters. This modification is corroborated by infrared and X-ray photoelectron spectroscopy analysis, and density functional theory calculations. Remarkably, the catalyst with 0.8 wt% K exhibits an optimal Pt electron density, driving its superior efficacy in the co-aromatization reaction, converting 0.78 mol of methane for each mole of hexane processed. By employing ~(13.C isotopic labeling and solid-state NMR studies, we demonstrate the participation of methane in the adsorbed species inside the zeolite channel and its incorporation to the benzyl site of the substitute group and phenyl rings in aromatic compounds, underscoring the importance of Pt encapsulation.

关键词： Pt encapsulation MFI zeolite methane activation co-aromatization ^(13.C solid-state NMR

Dynamic properties of micro-NPR material and its controlling effect on surrounding rock mass with impact disturbances

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Underground Space 2024年第2期15卷 331-352页

作者： Manchao he Jie Hu Tai Cheng Fei Deng Zhigang Tao Hongru {2. Di {3. Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China State Key laboratory for Geomechanics and Deep Underground Engineering China University of Mining&TechnologyBeijing 100083China Luohe Vocational Technology College Henan 462002China

A novel meta steel with negative Poisson’s ratio effect(termed as micro-NPR steel)is developed for rock support in deep underground *** possesses high strength,high ductility,and high energy absorption *** this paper,static tension and modified dynamic drop hammer tests are performed on this novel material to investigate its mechanical properties *** based on this material,a new generation of micro-NPR anchor cable is developed and applied in field tests subjected to blasting dynamic *** results of {2. tests reveal that t{3. ultimate elongation of micro-NPR steel under dynamic impacts is more than 3.%and it is over 1.5 times that of Q2.5;t{3. plastic and total energy absorption of micro-NPR are both significantly hig{3.r than that of *** test indicates t{3. fine controlling effect of micro-NPR anchor cable on surrounding rock mass under dynamic *** force confirms that micro-NPR cables can distribute and absorb t{3. dynamic energy uniformly around t{3. supported rock w{3.n subjected to dynamic disturbance,avoiding local failure induced by excessive stress *** excavation compensation principle and energy-absorbing characteristics are used to explain t{3. support ***,micro-NPR material and anchor cable can control and prevent dynamic disasters in deep underground engineering effectively.

关键词： Micro-NPR steel Energy-absorbing Drop hammer test Anchor cable Field test