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Using Natural Radionuclides to Trace Sources of Suspended Particles in the Lower Reaches of the Yellow River

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Journal of ocean University of China 2024年第1期23卷 99-108页

作者： ZHANG Han BURNETT CWilliam ZHANG Xiaojie ZHAO Shibin YANG Disong NAN Haiming YU Zhigang XU Bochao Frontiers Science Center for Deep ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and TechnologyMinistry of EducationOcean University of ChinaQingdao 266100China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China college of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahasseeFL 32306USA North China Sea Environmental Monitoring Center State Oceanic AdministrationKey Laboratory of Ecological Prewarning and Protection of Bohai SeaMNRQingdao 266033China Shandong Provincial Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation Qingdao 266033China

Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and *** analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year *** showed that medium silt(16–32µm)was the main *** expected,the activity of each radionuclide decreased with an increase of particle *** examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different *** results indicate that fine SPM(32µm)was mainly derived from resuspension of riverbed *** high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream *** occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea.

关键词： the Yellow River suspended particulate matter size-fractions radionuclides sediment sources water elutriator

Inversion of Seabed Geotechnical Properties in the Arctic Chukchi Deep Sea Basin Based on Time Domain Adaptive Search Matching Algorithm

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Journal of ocean University of China 2024年第4期23卷 933-942页

作者： AN Long XU Chong XING Junhui GONG Wei JIANG Xiaodian XU Haowei LIU Chuang YANG Boxue Jiangsu Automation Research Institute Lianyungang 222061China Key Laboratory of Submarine Geosciences and Prospecting Techniques MOE and College of Marine GeosciencesOcean University of ChinaQingdao 266100China Laboratory for Marine Mineral Resources Qingdao Marine Science and Technology CenterQingdao 266071China

The chirp sub-bottom profiler,for its high resolution,easy accessibility and cost-effectiveness,has been widely used in acoustic *** this paper,the acoustic impedance and grain size compositions were obtained based on the chirp sub-bottom profiler data collected in the Chukchi Plateau area during the 11th Arctic Expedition of *** time-domain adaptive search matching algorithm was used and validated on our established theoretical *** misfit between the inversion result and the theoretical model is less than 0.067%.The grain size was calculated according to the empirical relationship between the acoustic impedance and the grain size of the *** average acoustic impedance of sub-seafloor strata is 2.5026×10^(6) kg(s m^(2))^(-1)and the average grain size(θvalue)of the seafloor surface sediment is 7.1498,indicating the predominant occurrence of very fine silt sediment in the study *** of the inversion results and the laboratory measurements of nearby borehole samples shows that they are in general agreement.

关键词： time domain adaptive search matching algorithm acoustic impedance inversion sedimentary grain size Arctic ocean Chukchi Deep Sea Basin

Microbial Sulfate Reduction and Its Role in Carbon Sequestration in Marine Sediments

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Journal of Earth Science 2024年第4期35卷 1378-1381页

作者： Xiting Liu Houjie Wang Jiarui Liu Guang-Chao Zhuang Key Laboratory of Submarine Geosciences and Prospecting Technology College of Marine GeosciencesOcean University of ChinaQingdao266100China qingdao Marine Science and Technology Center Laboratory for Marine GeologyQingdao266237China Department of Earth Planetaryand Space SciencesUniversity of CaliforniaLos Angeles90095USA Frontiers Science Center for Deep ocean Multispheres and Earth System(FDOMES)and Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao266100China

0 INTRODUCTION The carbon buried in marine sediments in the form of organic carbon or carbonate minerals represents the largest pathway for carbon removal from Earth's surface environments(Sun and Turchyn,2014).Microbial sulfate reduction(MSR)is a fundamental biogeochemical process occurring in marine sediments,where sulfate-reducing bacteria(SRB)reduce sulfate(SO42-)to sulfide(S2-)using organic matter or methane as electron donors(Jorgensen,2021).

关键词： buried carbonate environments

Study of the ability of SWOT to detect sea surface height changes caused by internal solitary waves

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Acta oceanologica Sinica 2024年第5期43卷 54-64页

作者： Hao Zhang Chenqing Fan Lina Sun Junmin Meng First Institute of oceanography Ministry of Natural ResourcesQingdao 266061China Technology Innovation Center for ocean Telemetry Ministry of Natural ResourcesQingdao 266061China college of oceanography and Space Informatics China University of Petroleum(Huadong)Qingdao 266580China

Surface Water and ocean Topography(SWOT)is a next-generation radar altimeter that offers high resolution,wide swath,imaging *** has provided free public data worldwide since December *** paper aims to preliminarily analyze the detection capabilities of the Ka-band radar interferometer(KaRIn)and Nadir altimeter(NALT),which are carried out by SWOT for internal solitary waves(ISWs),and to gather other remote sensing images to validate SWOT *** effectively detects ISW surface features and generates surface height variation maps reflecting the modulations induced by ***,its swath width does not completely cover the entire wave packet,and the resolution of L2/L3 level products(about 2 km)cannot be used to identify ISWs with smaller ***,significant wave height(SWH)images exhibit blocky structures that are not suitable for ISW studies;sea surface height anomaly(SSHA)images display systematic leftright *** optimize this imbalance using detrending methods;however,more precise treatment should commence with L1-level *** analysis based on L3-level SSHA data indicates that the average SSHA variation induced by ISWs ranges from 10 cm to 20 *** disturbed by ISWs record unusually elevated SWH and SSHA values,rendering the data unsuitable for analysis and necessitating targeted corrections in future retracking *** the normalized radar cross section,Ku-band and four-parameter maximum likelihood estimation retracking demonstrated greater sensitivity to minor changes in the sea surface,making them more suitable for ISW *** conclusion,SWOT demonstrates outstanding capabilities in ISW detection,significantly advancing research on the modulation of the sea surface by ISWs and remote sensing imaging mechanisms.

关键词： internal solitary waves Surface Water and ocean Topography(SWOT) Ka-band radar interferometer(KaRIn) Nadir altimeter(NALT) sea surface height anomaly(SSHA) normalized radar cross section(NRCS)

Full waveform inversion based on hybrid gradient

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Petroleum Science 2024年第3期21卷 1660-1670页

作者： Chuang Xie Zhi-Liang Qin Jian-Hua Wang Peng Song Heng-Guang Shen Sheng-Qi Yu Ben-Jun Ma Xue-Qin Liu qingdao Innovation and Development Base Harbin Engineering UniversityQingdao266000ShandongChina qingdao Innovation and Development Center Harbin Engineering UniversityQingdao266000ShandongChina CNOOC Research Institute Co. Ltd.Beijing100028China college of Marine Geoscience Ocean University of ChinaQingdao266100ShandongChina Weihai Sunfull Geophysical Exploration Equipment Co. Ltd.Weihai264209ShandongChina

The low-wavenumber components in the gradient of full waveform inversion(FWI)play a vital role in the stability of the ***,when FWI is implemented in some high frequencies and current models are not far away from the real velocity model,an excessive number of low-wavenumber components in the gradient will also reduce the convergence rate and inversion *** solve this problem,this paper firstly derives a formula of scattering angle weighted gradient in FWI,then proposes a hybrid *** hybrid gradient combines the conventional gradient of FWI with the scattering angle weighted gradient in each inversion frequency band based on an empirical formula derived *** weighted hybrid mode,we can retain some low-wavenumber components in the initial lowfrequency inversion to ensure the stability of the inversion,and use more high-wavenumber components in the high-frequency inversion to improve the convergence *** results of synthetic data experiment demonstrate that compared to the conventional FWI,the FWI based on the proposed hybrid gradient can effectively reduce the low-wavenumber components in the gradient under the premise of ensuring inversion *** also greatly enhances the convergence rate and inversion accuracy,especially in the deep part of the *** the field marine seismic data experiment also illustrates that the FWI based on hybrid gradient(HGFWI)has good stability and adaptability.

关键词： Full waveform inversion Hybrid gradient Scattering angle weighted Low-wavenumber component

Simulated Indonesian Throughflow in Makassar Strait across the SODA3 products

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Acta oceanologica Sinica 2024年第1期43卷 80-98页

作者： Tengfei Xu Zexun Wei Haifeng Zhao Sheng Guan Shujiang Li Guanlin Wang Fei Teng Yongchui Zhang Jing Wang First Institute of oceanography/Key Laboratory of Marine Science and Numerical Modeling Ministry of Natural ResourcesQingdao 266061China Laboratory for Regional oceanography and Numerical Modeling Qingdao Marine Science and Technology CenterQingdao 266237China college of Meteorology and oceanography National University of Defense TechnologyChangsha 410073China CAS Key Laboratory of ocean Circulation and Waves Center for Ocean Mega-ScienceInstitute of OceanologyChinese Academy of ScienceQingdao 266071China

The Indonesian Throughflow(ITF), which connects the tropical Pacific and Indian oceans, plays important roles in the inter-ocean water exchange and regional or even global climate variability. The Makassar Strait is the main inflow passage of the ITF, carrying about 77% of the total ITF volume transport. In this study, we analyze the simulated ITF in the Makassar Strait in the Simple ocean Data Assimilation version 3(SODA3) datasets. A total of nine ensemble members of the SODA3 datasets, of which are driven by different surface forcings and bulk formulas, and with or without data assimilation, are used in this study. The annual mean water transports(i.e.,volume, heat and freshwater) are related to the combination of surface forcing and bulk formula, as well as whether data assimilation is employed. The phases of the seasonal and interannual variability in water transports cross the Makassar Strait, are basically consistent with each other among the SODA3 ensemble members. The interannual variability in Makassar Strait volume and heat transports are significantly correlated with El Ni?oSouthern Oscillation(ENSO) at time lags of-6 to 7 months. There is no statistically significant correlation between the freshwater transport and the ENSO. The Makassar Strait water transports are not significantly correlated with the Indian ocean Dipole(IOD), which may attribute to model deficiency in simulating the propagation of semiannual Kelvin waves from the Indian ocean to the Makassar Strait.

关键词： Indonesian Throughflow Simple ocean Data Assimilation(SODA) El Ni?o-Southern Oscillation(ENSO) Indian ocean Dipole(IOD) data assimilation

Inhibition effect of sulfation on Pt/TiO_(2) catalysts in methane combustion

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Chinese Journal of Structural Chemistry 2024年第5期43卷 18-21页

作者： Fanxin Kong Hongzhi Wang Huimei Duan School of Environmental Science and Engineering State Key Laboratory of Bio-fibers and Eco-textilesInstitute of Marine Biobased MaterialsQingdao UniversityQingdao266071China college of Chemistry and Chemical Engineering Ocean University of ChinaQingdao266100China

Methane as an attractive clean energy is a strong greenhouse gas with the global warming potential 86 times higher than that of CO_(2)over 20 years[1].Hence,the removal of unburned methane emitted from natural gas application processes is a serious environmental ***,methane is a geometrically high-symmetric and nonpolar molecule with high C-H bond energy(439 kJ mol^(-1))and low electron affinity(4.4 eV),rendering it extremely difficult to be activated under mild conditions[2].

关键词： methane rendering attractive

Expression and Characterization of a Novelλ-Carrageenase Cgl150A_Wa from Wenyingzhuangia aestuarii

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Journal of ocean University of China 2024年第1期23卷 209-215页

作者： SUN Yuhao CAO Siqi ZHANG Yuying XUE Changhu XIAO Hang CHANG Yaoguang college of Food Science and Engineering Ocean University of ChinaQingdao 266003China Marine Life Research Center Laoshan National LaboratoryQingdao 266237China Department of Food Science University of Massachusetts AmherstMA 01003United States

λ-Carrageenan is a highly sulfated polysaccharide alternating of 1,4-O-α-D-galactopyranose-2,6-sulfate(D2S,6S)and 1,3-O-β-D-galactopyranose-2-sulfate(G2S).λ-Carrageenases are desirable tools forλ-carrageenan *** on the genome mining,a novelλ-carrageenase Cgl150A_Wa was cloned from the bacterium Wenyingzhuangia aestuarii and expressed in Escherichia ***150A_Wa was an endo-acting enzyme and exhibited its maximum activity at 30℃and pH *** employing a glycomics strategy that combined ultra-performance liquid chromatography-mass spectrometry analysis and glycoinformatics,Cgl150A_Wa was proven to degradeλ-carrageenan octaose and hexaose,and the major hydrolysis product of Cgl150A_Wa wasλ-carrageenan *** addition to the typicalλ-carrageenan motifs,the active center of Cgl150A_Wa might tolerate desulfatedλ-carrageenan ***150A_Wa is a potential biotechnological tool for preparingλ-carrageenan oligosaccharides and structural investigation.

关键词： carrageenan λ-carrageenase LC-MS oligosaccharide GH150

Towards wafer-scale growth of two-dimensional cerium dioxide single crystal with high dielectric performance

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Nano Research 2024年第9期17卷 8592-8599页

作者： Zhuofeng Shi Muhammad Imran Xiaohui Chen Xin Liu Yaqi Zhu Zhaoning Hu Saiyu Bu Jialin Zhang Chunhu Li Xiaodong Zhang Li Lin college of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266000China School of Materials Science and Engineering Peking UniversityBeijing 100871China Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular ScienceCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationCollege of Chemistry and Chemical EngineeringOcean University of ChinaQingdao 266100China

Owing to the atomically thin nature,two-dimensional(2D)oxide materials have been widely reported to exhibit exciting transport and dielectric properties,such as fine gate controllability and ultrahigh carrier mobility,that outperform their bulk ***,unlike the successful synthesis of bulk oxide single crystals,reliable methods for synthesizing large-area single crystal of 2D oxide,that would suppress the negative influence from defective grain boundaries,remain unavailable,especially for nonlayered ***,we report that the lattice symmetry between the substrate and cerium dioxide(CeO_(2))would allow for the aligned nucleation and epitaxial growth of CeO_(2)on sapphire substrates,enabling the wafer-sized growth of CeO_(2)single *** careful tuning of the growth temperature and oxygen flow rate contributed to the harvesting of CeO_(2)wafer with reduced thickness and enhanced growth *** removal of grain boundaries improved the dielectric performance in terms of high dielectric strength(E_(bd)≈8.8 MV·cm^(-1)),suppressed leakage current,along with high dielectric constants(ε_(r)≈24).Our work demonstrates that with fine dielectric performance and ease of synthesizing wafer-sized single crystals,CeO_(2)can function as potential candidate as gate insulator for 2D-materials based nanoelectronics,and we believe the reported protocol of aligned nucleation can be extended to other 2D oxides.

关键词： dielectric materials two-dimensional materials chemical vapor deposition cerium dioxide