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A semantic segmentation-based underwater acoustic image transmission framework for cooperative SLAM

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Defence Technology（防务技术） 2024年第3期33卷 339-351页

作者： Jiaxu Li Guangyao Han Shuai Chang Xiaomei Fu school of marine science and Technology Tianjin UniversityTianjin 300072China

With the development of underwater sonar detection technology,simultaneous localization and mapping(SLAM)approach has attracted much attention in underwater navigation field in recent *** the weak detection ability of a single vehicle limits the SLAM performance in wide ***,cooperative SLAM using multiple vehicles has become an important research *** key factor of cooperative SLAM is timely and efficient sonar image transmission among underwater ***,the limited bandwidth of underwater acoustic channels contradicts a large amount of sonar image *** is essential to compress the images before ***,deep neural networks have great value in image compression by virtue of the powerful learning ability of neural networks,but the existing sonar image compression methods based on neural network usually focus on the pixel-level information without the semantic-level *** this paper,we propose a novel underwater acoustic transmission scheme called UAT-SSIC that includes semantic segmentation-based sonar image compression(SSIC)framework and the joint source-channel codec,to improve the accuracy of the semantic information of the reconstructed sonar image at the *** SSIC framework consists of Auto-Encoder structure-based sonar image compression network,which is measured by a semantic segmentation network's *** that sonar images have the characteristics of blurred target edges,the semantic segmentation network used a special dilated convolution neural network(DiCNN)to enhance segmentation accuracy by expanding the range of receptive *** joint source-channel codec with unequal error protection is proposed that adjusts the power level of the transmitted data,which deal with sonar image transmission error caused by the serious underwater acoustic *** results demonstrate that our method preserves more semantic information,with advantages over existing methods at the sa

关键词： Semantic segmentation Sonar image transmission Learning-based compression

Characterization,Expression Pattern Analysis,and Cellular Localization of Two Homologous MUC2 Genes in Japanese Flounder(Paralichthys olivaceus)

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Journal of Ocean University of China 2024年第4期23卷 1035-1044页

作者： ZHU Ying YANG Xinsheng LI Zhengjie LI Chao school of marine science and Engineering Qingdao Agricultural UniversityQingdao 266109China

As a member of mucins family,MUC2 is an important component of mucus,which is characterized by tandem and irregular repeat sequences rich in threonine and *** is strongly expressed by goblet cells that are involved in innate *** flounder is an economically important marine *** this study,two homologous genes of MUC2 were identified,named MUC2-1 and *** on phylogenetic and structural analysis,MUC2-1 and MUC2-2 were clustered in two clades,*** olivaceus MUC2-1 showed a closer relationship with MUC2 in the higher *** healthy tissues were analyzed to determine the expression patterns,and both MUC2 genes showed high expression levels in the gills and *** Edwardsiella tarda challenge,*** MUC2-1 and MUC2-2 both showed significant up-regulated expression in intestine and ***,MUC2-1 was significantly up-regulated in gill cell lines following PGN and polyI:C stimulation,and MUC2-2 was significantly up-regulated in gill cell lines following LPS *** addition,ISH results revealed that MUC2-1 and MUC2-2 showed the same tissue localization in intestine tissues,but displayed different localization in *** siRNA-mediated knockdown of MUC2-1 and MUC2-2 genes in the gill cell lines of Japanese flounder affected the expressions of galnt family genes and smad pathway members that are related to mucosal *** results provided a valuable insight into understanding the functions of MUC2 on mucosal immune system in response to the invasion of bacterial pathogen.

关键词： MUC2 ISH Edwardsiella tarda Paralichthys olivaceus

Application of the finite analytic numerical method to a flowdependent variational data assimilation

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Acta Oceanologica Sinica 2024年第3期43卷 30-39页

作者： Yan Hu Wei Li Xuefeng Zhang Guimei Liu Liang Zhang Tianjin Key Laboratory for marine Environmental Research and Service School of Marine Science and TechnologyTianjin UniversityTianjin 300072China school of marine science and Technology Tianjin UniversityTianjin 300072China National marine Environmental Forecasting Center Ministry of Natural ResourcesBeijing 100081China

An anisotropic diffusion filter can be used to model a flow-dependent background error covariance matrix,which can be achieved by solving the advection-diffusion *** of the directionality of the advection term,the discrete method needs to be chosen very *** finite analytic method is an alternative scheme to solve the advection-diffusion *** a combination of analytical and numerical methods,it not only has high calculation accuracy but also holds the characteristic of the auto *** demonstrate its ability,the one-dimensional steady and unsteady advection-diffusion equation numerical examples are respectively solved by the finite analytic *** more widely used upwind difference method is used as a control *** result indicates that the finite analytic method has higher accuracy than the upwind difference *** the two-dimensional case,the finite analytic method still has a better *** the three-dimensional variational assimilation experiment,the finite analytic method can effectively improve analysis field accuracy,and its effect is significantly better than the upwind difference and the central difference ***,it is still a more effective solution method in the strong flow region where the advective-diffusion filter performs most prominently.

关键词： finite analytic method advection-diffusion equation data assimilation flow-dependent

Lipase and photodecarboxylase coexpression: A potential strategy for alkane-based biodiesel production from natural triglycerides

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Chinese Journal of Chemical Engineering 2024年第3期67卷 238-246页

作者： Yong-Yi Zeng Xin-Yi Xu Jin-Xuan Xie Wen-Li Chen Lan Liu Xin-Jian Yin Bi-Shuang Chen school of marine sciences Sun Yat-Sen UniversityZhuhai 519080China Southern marine science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China

Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional ***,the formidable obstacle impeding the commercialization of this cutting-edge fuel alternative lies in the cost associated with its *** this study,an engineered strain Escherichia coli(***)showcasing harmonized coexpression of a lipase(from Thermomyces lanuginosus lipase,TLL)and a fatty acid photodecarboxylase(from Chlorella variabilis,CvFAP)was first constructed to transform triglycerides into *** potential of *** BL21(DE3)/pRSFDuet-1-TLL-CvFAP for alkane synthesis was evaluated with tripalmitin as a model substrate under various process *** a comprehensive examination of the reaction parameters,the scope of the biotransformation was expanded to‘real’substrates(vegetable oils).The results showed that bioderived oils can be transformed into alkanes with high yields(0.80-10.20 mmol·L^(-1))under mild conditions(35℃,pH 8.0,and 36 h)and blue light *** selected processes were performed on an increased lab scale(up to 100 ml)with up to 24.77 mmol·L^(-1) tripalmitin,leading to a yield of 18.89 mmol·L^(-1) *** the employment of a method for efficiently producing alkanes under mild conditions and a simple procedure to isolate alkanes from the reaction system,the utilization of sustainable biomass as a fundamental feedstock emerges as the primary solution to lower the cost of alkane-based ***,this study proposes a readily implementable and highly effective approach for alkane-based biodiesel production.

关键词： Alkane-based biodiesel Renewable biomass Co-overexpression Lipase Photodecarboxylase

Performance of physical-informed neural network (PINN) for the key parameter inference in Langmuir turbulence parameterization scheme

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Acta Oceanologica Sinica 2024年第5期43卷 121-132页

作者： Fangrui Xiu Zengan Deng school of marine science and Technology Tianjin UniversityTianjin 300072China

The Stokes production coefficient(E_(6))constitutes a critical parameter within the Mellor-Yamada type(MY-type)Langmuir turbulence(LT)parameterization schemes,significantly affecting the simulation of turbulent kinetic energy,turbulent length scale,and vertical diffusivity coefficient for turbulent kinetic energy in the upper ***,the accurate determination of its value remains a pressing scientific *** study adopted an innovative approach by leveraging deep learning technology to address this challenge of inferring the E_(6).Through the integration of the information of the turbulent length scale equation into a physical-informed neural network(PINN),we achieved an accurate and physically meaningful inference of E_(6).Multiple cases were examined to assess the feasibility of PINN in this task,revealing that under optimal settings,the average mean squared error of the E_(6) inference was only 0.01,attesting to the effectiveness of *** optimal hyperparameter combination was identified using the Tanh activation function,along with a spatiotemporal sampling interval of 1 s and 0.1 *** resulted in a substantial reduction in the average bias of the E_(6) inference,ranging from O(10^(1))to O(10^(2))times compared with other *** study underscores the potential application of PINN in intricate marine environments,offering a novel and efficient method for optimizing MY-type LT parameterization schemes.

关键词： Langmuir turbulence physical-informed neural network parameter inference

Plasma induced grain boundaries to boost electrochemical reduction of CO_(2)to formate

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Journal of Energy Chemistry 2024年第8期95卷 636-643,I0014页

作者： Guan Wang Shengtao Zhong Xiaoqian Xiong Jing Li Fangyuan Wang Li Huo Daoxiong Wu Xingqi Han Zhitong Wang Qi Chen Xinlong Tian Peilin Deng school of marine science and Engineering State Key Laboratory of Marine Resource Utilization in South China SeaHainan UniversityHaikou 570228HainanChina

Bismuth-based catalysts are highly promising for the electrochemical carbon dioxide reduction reaction(eCO_(2)RR)to formate ***,achieving high activity and selectivity towards formate and ensuring long-term stability remains *** work reports the oxygen plasma inducing strategy to construct the abundant grain boundaries of Bi/BiO_x on ultrathin two-dimensional Bi *** oxygen plasma-treated Bi nanosheet(OP-Bi)exhibits over 90%Faradaic efficiency(FE)for formate at a wide potential range from-0.5 to-1.1 V,and maintains a great stability catalytic performance without significant decay over 30 h in flow ***,membrane electrode assembly(MEA)device with OPBi as catalyst sustains the robust current density of 100 mA cm^(-2)over 50 h,maintaining a formate FE above 90%.In addition,rechargeable Zn-CO_(2)battery presents the peak power density of1.22 mW cm^(-2)with OP-Bi as bifunctional *** mechanism experiments demonstrate that the high-density grain boundaries of OP-Bi provide more exposed active sites,faster electron transfer capacity,and the stronger intrinsic activity of Bi *** situ spectroscopy and theo retical calculations further elucidate that the unsaturated Bi coordination atoms between the grain boundaries can effectively activate CO_(2)molecules through elongating the C-O bond,and reducing the formation energy barrier of the key intermediate(^(*)OCOH),thereby enhancing the catalytic performance of eCO_(2)RR to formate product.

关键词： CO_(2)electroreduction Bi nanosheet Grain boundary Unsaturation Bi atoms MEA device

Correlation of gut microorganisms and non-volatile flavor substances provides new insights for breeding Scylla paramamosain

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Journal of Oceanology and Limnology 2024年第4期42卷 1336-1347页

作者： Gao GAO Xing LI Kangxiang QIN Yun HU Xiaosong JIANG Chenxi CHE Yuntao LI Changkao MU Chunlin WANG Huan WANG school of marine science Ningbo UniversityNingbo 315211China Key Laboratory of Applied marine Biotechnology Ministry of EducationNingbo UniversityNingbo 315211China

The farming of Scylla paramamosain with specific flavors has a higher commercial value,and the flavors are related to the integrated farming environment and non-volatile flavor substances,while the survival environment is one of the important ways to source gut microorganisms in the *** this study,the levels of dominant taxa in the gut flora of *** from Mong Cai,Vietnam(VN),Taishan City,Guangdong Province(TS)of China,and Ninghai County,Ningbo City(NB)Zhejiang Province of China converged with those of *** from Sanmen County,Ningbo City(CK 1,CK 2,and CK 3)at 28 d of *** top 15 genera with the highest abundance of VN,TS,and NB gut flora were the same as CK 1,CK 2,and CK 3,but with different percentages,and gradually converged to CK 1,CK 2,and CK 3,respectively,at 28 d of *** between intestinal flora and non-volatile flavor substances in the hepatopancreas at the percentage level of relative abundance of bacterial genera found that above 28 d of domestication,Muribaculaceae,Psychrilyobacter,Clostridia_vadinBB 60_group,Halarcobacter Carboxylicivirga,Sediminispirochaeta may be the most important genera affecting flavor amino acids of ***,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Psychrilyobacter,and Pseudomonas may be the most important genera affecting flavor amino acids of ***,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Vibrio,and Sphingomonas may be the most important genera affecting flavor amino acids of *** results show that the intestinal flora structure of crabs from different areas were domesticated in the same area for at least 28 d before they converged to that of the domesticated crab,and the most important genera affecting the flavor amino acids of TS,VN,and NB were also *** results of this study provide a reference and basis for the technique of directional cultivation of the flavor quality of the crab.

关键词： survival environment Scylla paramamosain intestinal flora structure non-volatile flavor substance directional breeding

Facet effects on bimetallic ZnSn hydroxide microcrystals for selective electrochemical CO2 reduction

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Green Energy & Environment 2024年第8期9卷 1314-1320页

作者： Liu Han Cheng-wei Wang Shan-shan Luo Ying-tang Zhou Bing Li Ming Liu school of Chemistry and Chemical Engineering Harbin Institute of Technology National Engineering Research Center for marine Aquaculture Marine Science and Technology CollegeZhejiang Ocean University

Employing crystal facets to regulate the catalytic properties in electrocatalytic carbon dioxide reduction reaction（eCO2RR） has been well demonstrated on electrocatalysts containing single metals but rarely explored for bimetallic systems. Here, we synthesize Zn Sn（OH）6（ZSO）microcrystals（MCs） with distinct facets and investigate the facet effects in eCO2RR. Electrochemical studies and in situ Fourier Transform Infrared Spectroscopy（in situ-FTIR） reveal that ZSO MCs produce mainly C1 products of HCOOH and CO. The {111} facet of the ZSO MCS exhibits higher selectivity and faradaic efficiency（FE） than that of the {100} facet over a wide range of potentials（-0.9 V ～-1.3 V versus RHE）. Density Functional Theory（DFT） calculations elucidate that the {111} facet is favorable to the adsorption/activation of CO2molecules,the formation of intermediate in the rate-determining step, and the desorption of C1 products of CO and HCOOH molecules.

关键词： ZnSn(OH) 6 Crystal facets Electrochemical carbon dioxide reduction C1 product Density functional theory

RMPC-Based Visual Servoing for Trajectory Tracking of Quadrotor UAVs With Visibility Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 2027-2029页

作者： Qifan Yang Huiping Li school of marine science and Technology Northwestern Polytechnical UniversityXi’an 710072China

Dear Editor,This letter deals with the tracking problem of quadrotors subject to external disturbances and visibility constraints by designing a robust model predictive control(RMPC) scheme. According to the imagebase... 详细信息

关键词： Visual image visibility