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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

Spontaneous mutations and mutational responses to penicillin treatment in the bacterial pathogen Streptococcus pneumoniae D39

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Marine Life Science & Technology 2024年第3期6卷 198-211页

作者： Wanyue Jiang Tongtong Lin Jiao Pan Caitlyn ERivera Clayton Tincher Yaohai Wang Yu Zhang Xiang Gao Yan Wang Ho‑Ching T.Tsui Malcolm E.Winkler Michael Lynch Hongan Long Institute of Evolution and Marine Biodiversity KLMMEOcean University of ChinaQingdao 266003China Laboratory for Marine Biology and Biotechnology Laoshan LaboratoryQingdao 266237China Department of Biology Indiana UniversityBloomingtonIN 47405USA School of Mathematics Science Ocean University of ChinaQingdao 266000China State Key Laboratory of Microbial Technology Microbial Technology InstituteSchool of Life ScienceShandong UniversityQingdao 266237China Biodesign Center for Mechanisms of Evolution Arizona State UniversityTempeAZ 85281USA

Bacteria with functional DNA repair systems are expected to have low mutation rates due to strong natural selection for genomic ***,our study of the wild-type Streptococcus pneumoniae D39,a pathogen responsible for many common diseases,revealed a high spontaneous mutation rate of 0.02 per genome per cell division in mutation-accumulation(MA)*** rate is orders of magnitude higher than that of other non-mutator bacteria and is characterized by a high mutation bias in the A/T *** high mutation rate may have resulted from a reduction in the overall efficiency of selection,conferred by the tiny effective population size in *** line with this,*** D39 also exhibited the lowest DNA mismatch-repair(MMR)efficiency among *** with the antibiotic penicillin did not elevate the mutation rate,as penicillin did not induce DNA damage and *** lacks a stress response *** findings suggested that the MA results are applicable to within-host scenarios and provide insights into pathogen evolution.

关键词： Neutral evolution Mutation spectrum Antibiotics DNA mismatch repair Oxidative damage repair

Comparison and Verification of Coherent Doppler Wind Lidar and Radiosonde Data in the Beijing Urban Area

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Advances in Atmospheric Sciences 2024年第11期41卷 2203-2214页

作者： Zexu LUO Xiaoquan SONG Jiaping YIN Zhichao BU Yubao CHEN Yongtao YU Zhenlu ZHANG College of Marine Technology Faculty of Information Science and EngineeringOcean University of ChinaQingdao 266100China Laboratory for Regional oceanography and Numerical Modeling Laoshan LaboratoryQingdao 266237China qingdao Leice Transient Technology Co.LTD Qingdao 266100China CMA Meteorological Observation Centre Beijing 100081China Beijing Municipal Meteorological Observation Center Beijing 102600China qingdao Meteorological Comprehensive Support Center Qingdao 266003China

As a new type of wind field detection equipment, coherent Doppler wind lidar(CDWL) still needs more relevant observation experiments to compare and verify whether it can achieve the accuracy and precision of traditional observation equipment in urban areas. In this experiment, a self-developed CDWL provided four months of observations in the southern Beijing area. After the data acquisition time and height match, the wind profile data obtained based on a Doppler beam swinging(DBS) five-beam inversion algorithm were compared with radiosonde data released from the same location. The standard deviation(SD) of wind speed is 0.8 m s^(–1), and the coefficient of determination R~2 is 0.95. The SD of the wind direction is 17.7° with an R~2 of 0.96. Below the height of the roughness sublayer(about 400 m), the error in wind speed and wind direction is significantly greater than the error above the height of the boundary layer(about 1500 m). For the case of wind speeds less than 4 m s^(–1), the error of wind direction is more significant and is affected by the distribution of surrounding buildings. Averaging at different height levels using suitable time windows can effectively reduce the effects of turbulence and thus reduce the error caused by the different measurement methods of the two devices.

关键词： coherent Doppler wind lidar radiosonde wind measurement urban boundary layer

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)

Experimental Study on Consolidation Properties of Hydrate-Bearing Fine-Grained Sediments Collected from the Shenhu Area of the Northern South China Sea

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Journal of ocean university of China 2024年第4期23卷 981-990页

作者： WEI Ruchun LIU Lele JIA Chao DONG Xiao BU Qingtao ZHANG Yongchao LIU Changling WU Nengyou School of Water Conservancy and Environment University of JinanJinan 250022China Shandong Engineering Research Center of Marine Exploration and Conservation Ocean University of ChinaQingdao 266100China Key Laboratory of Gas Hydrate Ministry of Natural ResourcesQingdao Institute of Marine GeologyQingdao 266237China Institute of Marine Science and Technology Shandong UniversityQingdao 266232China

Mechanical properties of hydrate-bearing fine-grained sediments are crucial to effectively mitigate environmental risks caused by artificial and natural decomposition of natural gas hydrates,and the decomposition can induce laterally confined *** explore the effect of natural gas hydrates on laterally confined compression properties,consolidation tests are conducted on remolded hydrate-free and hydrate-bearing samples by using natural fine-grained sediments collected from the northern South China Sea as the host sediments,and empirical equations are developed based on the analyses of consolidation *** results show that vertical loading induces a reduction in void ratio,and the reduction increases with decreasing hydrate saturation when samples are subjected to the same vertical stress *** compression index of samples is about 0.53 whether there is hydrate or not,but the yield stress of samples increases sharply with increasing hydrate saturation once beyond the critical *** coefficient of volume compression and the coefficient of consolidation of hydrate-bearing samples both increase firstly and then decrease to a relative stable level with increasing vertical stress,and the transition occurs at 200 *** average consolidation degree with elapsed time increases rapidly under low vertical stresses,slowly under median vertical stresses,and under high vertical stresses,the consolidation increases a little faster but still slower than those under low vertical stresses.

关键词： natural gas hydrate stiffness compression index hydraulic permeability geohazard

Deep learning to estimate ocean subsurface salinity structure in the Indian ocean using satellite observations

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Journal of oceanology and Limnology 2024年第2期42卷 377-389页

作者： Jifeng QI Guimin SUN Bowen XIE Delei LI Baoshu YIN CAS Key Laboratory of ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China university of Chinese Academy of Sciences Beijing 100049China School of Mathematics and Physics Qingdao University of Science and TechnologyQingdao 266061China CAS Engineering Laboratory for Marine Ranching Institute of OceanologyChinese Academy of SciencesQingdao 266071China

Accurately estimating the ocean subsurface salinity structure(OSSS)is crucial for understanding ocean dynamics and predicting climate *** present a convolutional neural network(CNN)model to estimate the OSSS in the Indian ocean using satellite data and Argo *** evaluated the performance of the CNN model in terms of its vertical and spatial distribution,as well as seasonal variation of OSSS *** demonstrate that the CNN model accurately estimates the most significant salinity features in the Indian ocean using sea surface data with no significant differences from Argo-derived ***,the estimation accuracy of the CNN model varies with depth,with the most challenging depth being approximately 70 m,corresponding to the halocline *** of the CNN model’s accuracy in estimating OSSS in the Indian ocean are also conducted by comparing Argo observations and CNN model estimations along two selected sections and four selected *** results show that the CNN model effectively captures the seasonal variability of salinity,demonstrating its high performance in salinity estimation using sea surface *** analysis reveals that sea surface salinity has the strongest correlation with OSSS in shallow layers,while sea surface height anomaly plays a more significant role in deeper *** preliminary results provide valuable insights into the feasibility of estimating OSSS using satellite observations and have implications for studying upper ocean dynamics using machine learning techniques.

关键词： machine learning convolutional neural network(CNN) ocean subsurface salinity structure(OSSS) Indian ocean satellite observations

A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 965-981页

作者： Yong-Chao Li Rui-Sheng Jia Ying-Xiang Hu Hong-Mei Sun the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590 the Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266000China the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590China the College of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210000China

In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation *** this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised *** this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the ***,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd *** addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2).We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density *** experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and JHU-CROWD++.

关键词： Crowd density estimation linear feature calibration vision transformer weakly-supervision learning

Structural characteristics of phenylboronic acid-modified astaxanthin ester and its effect on DSS-induced ulcerative colitis by blocking reactive oxygen species and maintaining intestinal homeostasis

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Food Science and Human Wellness 2024年第5期13卷 2754-2764页

作者： Xing Qiao Hongyan Li Qun Gao Zhigao Wang Jie Xu Lu Yang Changhu Xue College of Food Science and Engineering Ocean University of ChinaQingdao 266003China College of Marine Science and Biological Engineering Qingdao University of Science and TechnologyQingdao 266042China Laboratory of Marine Drugs and Biological Products Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

A novel and reactive oxygen species(ROS)responsive astaxanthin phenylboronic acid derivative(AstaDPBA)was constructed by grafting phenylboronic acid(PBA)onto astaxanthin succinate diester(AstaD),and its chemical structure and physicochemical property were ***-PBA could effectively improve the ROS quenching ability in the lipopolysaccharide(LPS)-induced RAW264.7 cell inflammation ***,the bioactivity of AstaD-PBA was studied by 4 zebrafish ROS-responsive infl ammatory models induced by LPS,copper(Cu^(2+)),high-fat diet,and dextran sodium sulfate(DSS).The results suggest that AstaD-PBA might have high biosafety and the best effect on ulcerative colitis(UC)induced by ***,AstaDPBA significantly alleviated and treated weight loss and colonic shrinkage,inhibited infl ammatory cytokines,and maintained microbiota homeostasis to improve UC in C57BL/6J *** and Oscillibacter were expected to be considered UC marker fl ora according to the Metastats analysis and Pearson correlation Mantel test(P<0.01)of 16S rRNA gene sequencing *** conclusion,AstaD-PBA has been promised to be a functional compound to improve UC and maintain intestinal microbiota homeostasis.

关键词： Astaxanthin ester Reactive oxygen species-responsive Ulcerative colitis Intestinal microbiota Inflammatory cytokines

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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

Trimethylamine N-oxide generation process was influenced by the proportion and source of macronutrients in the diet

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Food Science and Human Wellness 2024年第2期13卷 649-658页

作者： Chengcheng Wang Xuefeng Duan Xiaoyue Li Jinyue Yang Changhu Xue Teruyoshi Yanagita Tiantian Zhang Yuming Wang College of Food Science and Engineering Ocean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Laboratory of Nutrition Biochemistry Department of Applied Biochemistry and Food ScienceSaga UniversitySaga 840-8502Japan

Trimethylamine N-oxide(TMAO)is a risk factor of various chronic diseases,which was produced by metabolism from precursors to trimethylamine(TMA)in gut and the oxidation from TMA in *** TMA generation was influenced by diet,mainly due to the rich TMAO precursors in ***,it was still unclear that the effects of different proportion and source of macronutrients in different dietary pattern on the production process of ***,the generation of TMA from precursors and TMAO from TMA was determined after single oral choline chloride and intraperitoneal injection TMA,respectively,in mice fed with carbohydrates,proteins and fats in different proportion and *** results suggested that the generation of TMAO was increased by low non-meat protein and high fat via enhancing the production of TMAO from TMA,and decreased by plant protein and refined sugar via reducing TMA production from precursors in gut and TMAO transformation from TMA in *** high fat and high sugar diets accelerating the development of atherosclerosis did not increase the production of TMAO,the risk factor for atherosclerosis,which indicated that the dietary compositions rather than the elevated TMAO level might be a more key risk factor for atherosclerosis.

关键词： Trimethylamine N-oxide(TMAO) Trimethylamine(TMA) Dietary composition Macronutrients Gut microbiota