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Coordination Mechanism and Empirical Research on marine science technology Innovation and marine Eco-civilization:A Case Study of Coastal Areas of China

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Chinese Geographical science 2024年第3期34卷 468-486页

作者： CHEN Xiaolong LIANG Chenlu DI Qianbin school of Geographical science Liaoning Normal UniversityDalian 116029China Institute of marine Sustainable Development Liaoning Normal UniversityDalian 116029China

marine science technology innovation provides power and guarantees for marine eco-civilization construction,which provides direction and material support for marine science technology innovation.Therefore,the coordinated development of the two is of great significance to the marine economy sustainable development in China’s coastal areas.On the basis of clarifying the connotations of marine science technology innovation and marine eco-civilization in China’s coastal areas from 2006 to 2019,the mechanism for their coordinated development was analysed.A comprehensive indicator system based on the connotation of the two was constructed,and the coordinated development relationship was empirically tested using the coupled coordination model and the panel vector autoregressive(PVAR)model.The results show that:1)the level of China’s coastal marine science technology innovation continues to improve,gradually forming the core of the development of marine science technology innovation in the north,east and south of Shandong,Shanghai and Guangdong;the level of marine eco-civilization development fluctuating upward trend,showing obvious spatial differentiation characteristics.2)The degree of coordination of marine science technology innovation and marine eco-civilization is growing over time.There is no causal relationship between marine science technology innovation and marine eco-civilization in the northern marine economic circle,but there is a two-way causal relationship between the two in the eastern and southern marine economic circles.3)marine eco-civilization shows a significant positive and continuous impact on marine science technology innovation,and marine science technology innovation shows a long-term,continuous,fluctuating,and lagging impact on marine eco-civilization.The overall role of marine eco-civilization on marine science technology innovation is dominant,and there are significant differences in the impact effects of the two major marine economic circles.

关键词： marine science technology innovation marine eco-civilization coordinated development coastal areas of China

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Effect of compressive strength on the performance of the NEMO-LIM model in Arctic Sea ice simulation

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Journal of Oceanology and Limnology 2023年第1期41卷 1-16页

作者： Chunming DONG Xiaofan LUO Hongtao NIE Wei ZHAO Hao WEI school of marine science and technology Tianjin UniversityTianjin 300072China

Satellite records show that the extent and thickness of sea ice in the Arctic Ocean have significantly decreased since the early 1970s.The prediction of sea ice is highly important,but accurate simulation of sea ice variations remains highly challenging.For improving model performance,sensitivity experiments were conducted using the coupled ocean and sea ice model(NEMO-LIM),and the simulation results were compared against satellite observations.Moreover,the contribution ratios of dynamic and thermodynamic processes to sea ice variations were analyzed.The results show that the performance of the model in reconstructing the spatial distribution of Arctic sea ice is highly sensitive to ice strength decay constant(C^(rhg)).By reducing the C^(rhg) constant,the sea ice compressive strength increases,leading to improved simulated sea ice states.The contribution of thermodynamic processes to sea ice melting was reduced due to less deformation and fracture of sea ice with increased compressive strength.Meanwhile,dynamic processes constrained more sea ice to the central Arctic Ocean and contributed to the increases in ice concentration,reducing the simulation bias in the central Arctic Ocean in summer.The root mean square error(RMSE)between modeled and the CryoSat-2/SMOS satellite observed ice thickness was reduced in the compressive strength-enhanced model solution.The ice thickness,especially of multiyear thick ice,was also reduced and matched with the satellite observation better in the freezing season.These provide an essential foundation on exploring the response of the marine ecosystem and biogeochemical cycling to sea ice changes.

关键词： sea ice compressive strength sensitivity experiment ocean-sea ice model Arctic Ocean

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Heterogeneous activation of persulfate by CuMgAl layered double oxide for catalytic degradation of sulfameter

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Green Energy & Environment 2022年第1期7卷 105-115页

作者： Hongmin Zhang Qingzhu Jia Fangyou Yan Qiang Wang school of marine and Environmental science Tianjin Marine Environmental Protection and Restoration Technology Engineering CenterTianjin University of Science and TechnologyTianjin300457China school of Chemical Engineering and Material science Tianjin University of Science and TechnologyTianjin300457China

In this study,a series of CuMgAl layered double oxides(CuMgAl-LDOs)were obtained via calcination of CuMgAl layered double hydroxides(CuMgAl-LDHs)synthesised via a co-precipitation method.The results show that CuMgAl-LDO can be prepared using an optimal Cu:Mg:Al molar ratio of 3:3:2,NaOH:Na_(2)CO_(3)molar ratio of 2:1,and calcination temperature of 600°C.CuMgAl-LDO is a characteristic of mesoporous material with a lamellar structure and large specific surface area.The removal efficiency of sulfameter(SMD)based on CuMgAl-LDO/persulfate(PS)can reach>98%over a wide range of initial SMD concentrations(5–20 mg L^(-1)).The best removal efficiency of99.49%was achieved within 120 min using 10 mg L^(-1)SMD,0.3 g L^(-1)CuMgAl-LDO,and 0.7 mmol L^(-1)PS.Kinetic analysis showed that the degradation of SMD was in accordance with a quasi-first-order kinetic model.The stability of the CuMgAl-LDO catalyst was verified by the high SMD removal efficiency(>97%within 120 min)observed after five recycling tests and low copper ion leaching concentration(0.89 mg L^(-1)),which is below drinking water quality standard of 1.3 mg L^(-1)permittable in the U.S.Radical scavenging experiments suggest that SO_(4)^(-)is the primary active species participating in the CuMgAl-LDO/PS system.Moreover,our mechanistic investigations based on the radical scavenging tests and X-ray photoelectron spectroscopy(XPS)results indicate that Cu^((II))-Cu^((III))-Cu^((II))circulation is responsible for activating PS in the degradation of SMD and the degradation pathway for SMD was deduced.Accordingly,the results presented in this work demonstrate that CuMgAl-LDO may be an efficient and stable catalyst for the activation of PS during the degradation of organic pollutants.

关键词： CuMgAl-LDO Heterogeneous catalysis Activated persulfate Sulfameter Reaction mechanism

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Lattice Boltzmann modeling of backward-facing step flow controlled by a synthetic jet

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Journal of Hydrodynamics 2023年第4期35卷 757-769页

作者： Tian-yang Lu Hai-bao Hu Jian Song Fan Zhang Heng Zhang Zhen-lin Xie Feng Ren school of marine science and technology Northwestern Polytechnical UniversityXi’an710072China

This article investigates the effect of a synthetic jet(SJ)on the flow over a backward-facing step(BFS)in the weakly turbulent flow regime using the lattice Boltzmann method.The SJ operates with various momentum coefficients Cμand forcing frequencies f^(*)_(jet).As Cμincreases,the reattachment length decreases,whereas increasing f^(*)_(jet) causes the reattachment length at first decrease and then increase.A minimum reattachment length appears at Cμ=0.3125,f^(*)_(jet)=1.6,corresponding to a 40%reduction compared with the uncontrolled case.Two mechanisms for the mediated flow are found:(1)A suitable control frequency leads to a lock-on state that prompts vertical momentum transfer and laminarizes the flow near the separation point,(2)Regular vortices emerge after wall reattachment in controlled cases.Fast Fourier and wavelet transform of the velocity near the separation point reveal that the monitored frequency becomes locked-on when f^(*)_(jet)>1.6,making the flow quasi-periodic and dramatically reducing the reattachment length.Turbulent kinetic energy spectra indicate that the monitored frequencies are dominated by the forcing frequency and that active control laminarizes the local flow.Proper orthogonal decomposition is used to extract coherent structures at multiple scales.In the dominant mode,reattaching wake vortices are regulated by active control.In the second mode,irregular wake vortices emerge after f^(*)_(jet)=2,which attenuates the SJ forcing and increases the reattachment length.This study provides insights on typical flows past a BFS and will shed more light on the design of closed-loop control strategies for separation flows.

关键词： Lattice Boltzmann method(LBM) flow control synthetic jet proper orthogonal decomposition

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Straight-Path Following and Formation Control of USVs Using Distributed Deep Reinforcement Learning and Adaptive Neural Network

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IEEE/CAA Journal of Automatica Sinica 2023年第2期10卷 572-574页

作者： Zhengqing Han Yintao Wang Qi Sun the School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China

Dear Editor,This letter presents a distributed deep reinforcement learning(DRL) based approach to deal with the path following and formation control problems for underactuated unmanned surface vehicles(USVs). By constructing two independent actor-critic architectures,the deep deterministic policy gradient(DDPG) method is proposed to determine the desired heading and speed command for each USV.

关键词： Deep policy heading

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Spatial diff erence in net growth rate of Yesso scallop Patinopecten yessoensis revealed by an aquaculture ecosystem model

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Journal of Oceanology and Limnology 2022年第1期40卷 373-387页

作者： Xueliang NAN Hao WEI Haiyan ZHANG Hongtao NIE school of marine science and technology Tianjin UniversityTianjin 300072China

Identifying the main factors on spatial diff erences in net growth rate of Yesso scallop(Patinopecten yessoensis)in culture system is the key to eff ective aquaculture management and development.Coupling a 3D ecosystem model(ROMS-CoSiNE)with a dynamic energy budget model for scallops,a Yesso scallop culture ecosystem(YeSCE)model was established with which scallop growth was simulated with real seeding density and juvenile size from local aquaculture experiments from December 1,2012 to November 30,2013.Results show that the YeSCE model has reasonably simulated the environmental variation and scallop net growth rate in the Changhai sea area.The growth of scallops was slow in winter and midsummer and was limited mainly by temperature.Food availability was a key factor that contributed to the fast growth of the scallops during spring to early summer and in autumn.Generally,the scallops cultured in the north part of the Changhai sea area grew faster than those in the south;and the net growth rate for scallops cultured near the island was signifi cantly higher compare to the others,which is probably correlated to the spatial distribution of food availability.Based on the correlation analysis,the spatial diff erences of the net growth rate were largely aff ected by the length of the match timing of temperatures and food availability.The results of this study provide a scientifi c support for optimizing bottom culture planning and adjusting bottom culture methods.

关键词： 3D ecosystem model shellfi sh aquaculture Yesso scallop Patinopecten yessoensis net growth rate Changhai sea area

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Channel Estimation for OTFS System over Doubly Spread Sparse Acoustic Channels

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China Communications 2023年第1期20卷 50-65页

作者： Yang Zhang Qunfei Zhang Chengbing He Chao Long school of marine science and technology Northwestern Polytechnical UniversityXi’an 710072China

This paper addresses sparse channels estimation problem for the generalized linear models(GLM)in the orthogonal time frequency space(OTFS)underwater acoustic(UWA)system.OTFS works in the delay-Doppler domain,where timevarying channels are characterized as delay-Doppler impulse responses.In fact,a typical doubly spread UWA channel is associated with several resolvable paths,which exhibits a structured sparsity in the delayDoppler domain.To leverage the structured sparsity of the doubly spread UWA channel,we develop a structured sparsity-based generalized approximated message passing(GAMP)algorithm for reliable channel estimation in quantized OTFS systems.The proposed algorithm has a lower computational complexity compared to the conventional Bayesian algorithm.In addition,the expectation maximum algorithm is employed to learn the sparsity ratio and the noise variance.Simulation and experimental results show that the proposed algorithm has superior performance and low computational complexity for quantized OTFS systems.

关键词： OTFS doubly spread UWA channel delay-Doppler domain GAMP

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Contraction and warming of Antarctic Bottom Water in the Amundsen Sea

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Acta Oceanologica Sinica 2022年第4期41卷 68-79页

作者： Yu Bai Liang Zhao Jingen Xiao Shiying Lin College of marine and Environmental sciences Tianjin University of Science and TechnologyTianjin 300457China school of marine science and technology Tianjin UniversityTianjin 300072China

Antarctic Bottom Water(AABW)plays an important role in the meridional overturning circulation and contributes significantly to global heat transport and sea level rise(SLR).Based on the Global Ocean(1/12)°Physical Reanalysis(GLORYS12V1)products and conductivity-temperature-depth instrument data from the World Ocean Circulation Experiment hydrographic program,we analyzed the trends in the thickness,volume,temperature,salinity,and neutral density of the AABW in the Amundsen Sea from 1993 to 2017.Over the past 25 years,the volume has decreased by 3.45×10^(12) m^(3)/a,thinning at a rate of 5 m/a.In the vertical direction,the contraction of the AABW is compensated by the volume expansion of the Circumpolar Deep Water.As the volume of AABW decreases,the temperature of the AABW increases by about 0.002℃/a.This warming is equivalent to a heat flux of 0.27 W/m^(2).A local SLR is produced due to thermal expansion of 0.35 mm/a.During the study period,the neutral density decreased by 0.0003 kg/(m^(3)·a)due to warming.In the horizontal direction,the volume of AABW flowing from the Ross Sea into the Amundsen Sea gradually decreases and the temperature of the AABW increases continuously.The horizontal transport loss of the AABW volume is 4.07×10^(14) m^(3) and the horizontal heat transport results in a 0.03℃ increase in the temperature of the AABW.

关键词： Antarctic Bottom Water Amundsen Sea thickness volume hydrographic property

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The effects of ripple amplitude on heat transfer and fluid flow of X-lattice corrugated honeycombs

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science China(Technological sciences) 2023年第12期66卷 3412-3421页

作者： CHEN JunJun XIE GongNan YAN HongBin school of marine science and technology Northwestern Polytechnical UniversityXi’an 710072China school of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China

A previous study showed that the thermal performance of the X-lattice cored corrugated honeycomb(XCCH)is better than that of most other periodic cellular materials(PCMs).To further improve the thermal performance of the XCCH,the effects of different ripple amplitudes(i.e.,a=0.5,0.7 and 1.0)on the characteristics of the flow and heat transfer are numerically investigated by thorough comparisons.In terms of the flow characteristics,with the increase of ripple amplitude,the vortex interaction in the channel becomes stronger,which results in evident increase of kinetic energy of turbulence at the boundary of vortex and reduction in the turbulent kinetic energy dissipation.As far as the heat transfer is concerned,within the Reynolds number range of 3696–7436,the heat transfer increases with the increase of ripple amplitude.The overall Nusselt number of the XCCH with a=1.0 is 15.7%higher than that with a=0.5.Within the corresponding range of pumping power,the thermal performance of the XCCH with a=1.0 is up to 7%higher than that with a=0.5 at relatively higher Reynolds numbers.

关键词： X-lattice honeycomb ripple amplitude enhanced heat transfer turbulent flow

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Embedding Cross-Dimensional Vector Space into ?2

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Journal of Systems science & Complexity 2023年第6期36卷 2309-2324页

作者： XUE Shengli ZHANG Lijun XIE Zhiqi YAN Weijun ZHANG Kuize school of marine science and technology Northwestern Polytechnical University school of Mathematics and Statistics Yulin University Department of Computer science University of Surrey

The cross-dimensional dynamical systems have received increasing research attention in recent years. This paper characterizes the structure features of the cross-dimensional vector space.Specifically, it is proved that the completion of cross-dimensional vector space is an infinite-dimensional separable Hilbert space. Hence, it means that one can isometrically and linearly embed the crossdimensional vector space into the ?2, which is known as the space of square summable sequences.This result will be helpful in the modeling and analyzing the dynamics of cross-dimensional dynamical systems.

关键词： Cross-dimensional vector space ℓ 2 space semi-tensor product separable Hilbert space \({\cal V}\) -equivalence

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