Establishing a Regional Marine Innovation Ecosystem(RMIE)is crucial for advancing China’s maritime power strategy.Concurrently,developing a competitive RMIE serves as a strategic lever to enhance the global competiti...Establishing a Regional Marine Innovation Ecosystem(RMIE)is crucial for advancing China’s maritime power strategy.Concurrently,developing a competitive RMIE serves as a strategic lever to enhance the global competitiveness of China’s marine science sector.However,research on the competitiveness of RMIE is limited.To this end,this study constructs an evaluation index system based on ecological niche theory to assess the competitiveness of RMIE in China from 2008 to 2020.The findings indicate generally fluctuating upward trends in RMIE’s competitiveness,with Shandong,Jiangsu,and Guangdong showing relatively strong positions.Notably,there are significant intra-regional imbalances and inter-regional asynchrony in RMIE’s competitiveness across China’s three major marine economic circles.Recognizing that forecasting RMIE competitiveness can inform policy formulation,this paper proposes a systematic multivariate grey interval prediction model that incorporates spatial proximity effects.This model effectively captures the interval and uncertainty characteristics of RMIE’s competitiveness while considering spatial relationships among regions.Results from comparative analysis,robustness tests,and sensitivity analysis demonstrate its superior applicability and forecasting accuracy.Additionally,interval forecasts and scenario analyses suggest that RMIE competitiveness will maintain stable growth,although unbalanced and unsynchronized development is likely to persist.Overall,the approach developed for evaluating and forecasting RMIE competitiveness offers valuable insights for effective policy formulation.展开更多
Assessing the carbon sink potential of marine aquaculture is critical to fostering sustainable marine economic development and achieving carbon neutrality.This study evaluates the carbon sink potential of four nearsho...Assessing the carbon sink potential of marine aquaculture is critical to fostering sustainable marine economic development and achieving carbon neutrality.This study evaluates the carbon sink potential of four nearshore aquaculture systems in China:floating raft,net cage,pond,and tidal flat.China’s coastal aquaculture shows a dramatic potential range from−5401.28×10^(4)t to 84.65×10^(4)t,acting as both a carbon sink and a source.Floating raft(11.19×10^(4)t to 105.65×10^(4)t)and tidal flat(42.83×10^(4)t to 114.35×10^(4)t)are net carbon sinks.In contrast,net cage(−427.39×10^(4)t to−4.26×10^(4)t)and pond(−5027.91×10^(4)t to−131.09×10^(4)t)are significant net carbon sources.This heterogeneity is driven by differences in species,feed inputs,energy consumption,and management practices.The results highlight the need for targeted low-carbon technologies in high-emission systems to maximize carbon sequestration and mitigate their environmental impacts.This study provides a scientific basis for optimizing carbon management and offers insights for global sustainable aquaculture and carbon neutrality.展开更多
High-quality development of marine fisheries provides an important advantage for China to build itself into a maritime power and implement the Blue Granary Plan effectively.Based on the concepts of‘new development’,...High-quality development of marine fisheries provides an important advantage for China to build itself into a maritime power and implement the Blue Granary Plan effectively.Based on the concepts of‘new development’,‘food security’,and the six dimensions of‘openness,innovation,coordination,green,sharing,and security’,in this study,we established an evaluation index system for the high-quality development of China’s marine fishery sector.We applied the entropy method to evaluate the high-quality development level of China’s marine fishery sector from 2000 to 2016 and explored its spatial and temporal evolution rules.Our results indicated that:1)from 2000 to 2016,China’s marine fishery sector was in the primary stage of high-quality development;2)spatially,the highquality development of marine fisheries showed an upward trend in all provinces,autonomous regions,and municipalities in the country(not including Hong Kong,Macao and Taiwan of China),and with time,the distribution pattern changed from single to multi-polarization;3)temporally,the development level of high-quality marine fisheries fluctuated during the study period.From 2000 to 2010,the growth rate in openness was relatively slow,but after 2010,it increased rapidly.Notably,innovation is the driving force for high-quality development.The green and security factors provide a solid guarantee for high-quality development.In the high-quality development of a region,economic development is better coordinated,and the distribution of benefits is more inclusive.This study provides a theoretical basis to formulate effective marine fishery policies for the high-quality development of the marine fishery sector in China.Exploring the high-quality development and evolution process of marine fishery is conducive to promoting the sustainable development of marine fishery industry,ensuring marine fishery food security,and alleviating global food crisis.展开更多
The performance of data restore is one of the key indicators of user experience for backup storage systems.Compared to the traditional offline restore process,online restore reduces downtime during backup restoration,...The performance of data restore is one of the key indicators of user experience for backup storage systems.Compared to the traditional offline restore process,online restore reduces downtime during backup restoration,allowing users to operate on already restored files while other files are still being restored.This approach improves availability during restoration tasks but suffers from a critical limitation:inconsistencies between the access sequence and the restore sequence.In many cases,the file a user needs to access at a given moment may not yet be restored,resulting in significant delays and poor user experience.To this end,we present Histore,which builds on the user’s historical access sequence to schedule the restore sequence,in order to reduce users’access delayed time.Histore includes three restore approaches:(i)the frequency-based approach,which restores files based on historical file access frequencies and prioritizes ensuring the availability of frequently accessed files;(ii)the graph-based approach,which preferentially restores the frequently accessed files as well as their correlated files based on historical access patterns,and(iii)the trie-based approach,which restores particular files based on both users’real-time and historical access patterns to deduce and restore the files to be accessed in the near future.We implement a prototype of Histore and evaluate its performance from multiple perspectives.Trace-driven experiments on two datasets show that Histore significantly reduces users’delay time by 4-700×with only 1.0%-14.5%additional performance overhead.展开更多
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 coordina...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.展开更多
Data on discrete,isolated attributes of the marine economy are often used in traditional marine economic research.However,as the focus of urban research shifts from internal static attributes to external dynamic linka...Data on discrete,isolated attributes of the marine economy are often used in traditional marine economic research.However,as the focus of urban research shifts from internal static attributes to external dynamic linkages,the importance of marine economic net-work research is beginning to emerge.The construction of the marine economic network in China’s coastal areas is necessary to change the flow of land and sea resources and optimize regional marine economic development.Employing data from headquarters and branches of sea-related A-share listed enterprises to construct the marine economic network in China,we use social network analysis(SNA)to discuss the characteristics of its evolution as of 2010,2015,and 2020 and its governance.The following results were obtained.1)In terms of topological characteristics,the scale of the marine economic network in China’s coastal areas has accelerated and expan-ded,and the connections have become increasingly close;thus,this development has complex network characteristics.2)In terms of spatial structure,the intensity of the connection fluctuates and does not form stable development support;the group structure gradually becomes clear,but the overall pattern is fragmented;there are spatial differences in marine economic agglomeration radiation;the radi-ation effect of the eastern marine economic circle is obvious;and the polarization effect of northern and southern marine economic circles is significant.On this basis,we construct a framework for the governance of a marine economic network with the market,the government,and industry as the three governing bodies.By clarifying the driving factors and building objectives of marine economic network construction,this study aims to foster the high-quality development of China’s marine economy.展开更多
The complex relationship between humans and nature plays a key role in shaping geographic landscapes.This study examines how tourism transforms island landscapes into marketable commodities,focusing on Guanglu Island ...The complex relationship between humans and nature plays a key role in shaping geographic landscapes.This study examines how tourism transforms island landscapes into marketable commodities,focusing on Guanglu Island in China from 2002–2025 through the lens of Actor-Network Theory(ANT).The findings reveal three main insights:1)commodification involves reimagining natural landscapes,digitizing them for broader appeal,and integrating them into tourist consumption.2)This process reshapes original landscapes into four interconnected forms:material landscapes,fluid landscapes,virtual landscapes,and psychological landscapes.3)Multiple actors drive commodification:the island’s natural conditions provide foundation and influence concrete ways of commodification,local government is deeply involved through planning and regulating tourism development,tourism practitioners adapt services to market demands,and tourist preferences guide the direction of commercialization.By analyzing the roles of both human and non-human actors,this research highlights how tourism redefines island landscapes while emphasizing the active influence of nature itself in these transformations.The findings reveal the geographical attributes of landscape commodification process and the multidimensionality and complexity of its impacts,thereby providing valuable insights for the sustainable development of island tourism.展开更多
The evolution mechanism of railway transportation network nodes driven by sea-rail intermodal transport(SRIT),a globally prevalent logistics method,has not been thoroughly investigated.From the perspective of SRIT,thi...The evolution mechanism of railway transportation network nodes driven by sea-rail intermodal transport(SRIT),a globally prevalent logistics method,has not been thoroughly investigated.From the perspective of SRIT,this study constructed a framework for understanding the evolution of railway container transport network nodes using Northeast China from 2013 to 2020 as a case study.It leverages proprietary data from 95306 Railway Freight E-commerce Platform.By employing the hybrid EWM-GA-TOPSIS model,complex network analysis,modified gravity model,and correlation and regression analyses,this study delves into the spatiotemporal patterns and dynamic transformations of railway container freight stations(RCFS).Finally,the long-term relationship between the RCFS and SRIT is explored.The results indicate that the spatial and temporal analysis of the RCFS in Northeast China from 2013 to 2020 revealed a clear polarisation trend,with the top-ranked stations mainly concentrated near ports and important transportation hubs.Additionally,the RCFS exhibited an expansionary trend;however,its development was uneven,and there was a significant increase in the number of new stations compared to abandoned stations,indicating an overall positive growth tendency.Moreover,the intensity of the SRIT at the RCFS in Northeast China notably increased.A significant positive linear relationship exists between SRIT and the freight capacity of all stations.A relatively pronounced correlation was observed for high-intensity stations,whereas a relatively weak correlation was observed for low-intensity stations.This study not only provides an effective framework for future research on RCFS within the context of SRIT but also serves as a scientific reference for promoting the implementation of the national strategy for multimodal transportation.展开更多
Poly(vinyl alcohol)(PVA)hydrogels have garnered significant attention for tissue engineering,wound dressing,and electronic skin sensing applications.However,their poor mechanical performance severely restricts their m...Poly(vinyl alcohol)(PVA)hydrogels have garnered significant attention for tissue engineering,wound dressing,and electronic skin sensing applications.However,their poor mechanical performance severely restricts their multifunctional application in many scenarios.To address this limitation,PVA/tannic acid(TA)@carbon nanotubes(PVA/TA@CNTs)composite hydrogels with triple crosslinking networks were prepared through freezing-thawing and the solvent-induced shrinkage method,utilizing tannic acid-carbon nanotubes(TA@CNTs)as reinforcing units and a Ca^(2+)crosslinking strategy.The enhanced interfacial networks consisting of PVA crystalline domains,hydrogen bonding,and metal coordination endowed the composite hydrogel with a high mechanical strength,excellent flexibility,and fracture toughness,accompanied by a significant increase in crystallinity.The tensile strength and fracture toughness of the composite hydrogel reached up to about 7.0 MPa and 17.0MJ/m^(3),which were roughly 8 and 10 times higher than those of neat PVA hydrogel,respectively.The composite hydrogel demonstrated good cytocompatibility,significantly addressing the challenge of balancing structural reinforcement with biosafety in hydrogels.This methodology establishes a rational design for fabricating mechanically robust yet tough PVA hydrogels for biomedical applications.展开更多
Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard a...Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard assessment of SSEs,this study introduced the concept of the storm surge event seawater-atmosphere system(SSE-SAS)and proposed the system energy equivalence(SEE)model from a systemic energy perspective.SEE was obtained by employing a parameterization approach,and the hazard index(HI)and the concept of most significant hazard(MSH)were adopted to evaluate the severity of SSE-SAS.SEE at five stations in the Shandong Peninsula was calculated from 2005 to 2019,and probability analysis and hazard assessment were further conducted.Results show that the SEE of SSE-SAS ranges from 0.029×10^(3) to 30.418×10^(3) J/m^(2),and it exhibits an insignificant decreasing trend from 2005 to 2019.The SEE of SSE-SAS in the west of the Shandong Peninsula is greater than that in the east.Moreover,storm waves,storm surges,and storm rainfall are the major contributors to SEE,which exhibit different spatial patterns and characters in different SSE-SAS types.The HI of SSE-SAS at five stations is no more than medium hazard level,with MSH at return periods of 2-to 4-year level.This study provides a new approach for quantifying multi-hazard SSEs,which offers scientific insights for regional multi-hazard risk reduction and mitigation efforts.展开更多
There are eight provinces and autonomous regions(Gansu Province,Ningxia Hui Autonomous Region,Xinjiang Uygur Autonomous Region,Inner Mongolia Autonomous Region,Tibet Autonomous Region,Qinghai Province,Shanxi Province,...There are eight provinces and autonomous regions(Gansu Province,Ningxia Hui Autonomous Region,Xinjiang Uygur Autonomous Region,Inner Mongolia Autonomous Region,Tibet Autonomous Region,Qinghai Province,Shanxi Province,and Shaanxi Province)in Northwest China,most areas of which are located in arid and semi-arid regions(northwest of the 400 mm precipitation line),accounting for 58.74%of the country's land area and sustaining approximately 7.84×10^6 people.Because of drought conditions and fragile ecology,these regions cannot develop agriculture at the expense of the environment.Given the challenges of global warming,the green total factor productivity(GTFP),taking CO2 emissions as an undesirable output,is an effective index for measuring the sustainability of agricultural development.Agricultural GTFP can be influenced by both internal production factors(labor force,machinery,land,agricultural plastic film,diesel,pesticide,and fertilizer)and external climate factors(temperature,precipitation,and sunshine duration).In this study,we used the Super-slacks-based measure(Super-SBM)model to measure agricultural GTFP during the period 2000-2016 at the regional level.Our results show that the average agricultural GTFP of most provinces and autonomous regions in arid and semi-arid regions underwent a fluctuating increase during the study period(2000-2016),and the fluctuation was caused by the production factors(input and output factors).To improve agricultural GTFP,Shaanxi,Shanxi,and Gansu should reduce agricultural labor force input;Shaanxi,Inner Mongolia,Gansu,and Shanxi should decrease machinery input;Shaanxi,Inner Mongolia,Xinjiang,and Shanxi should reduce fertilizer input;Shaanxi,Xinjiang,Gansu,and Ningxia should reduce diesel input;Xinjiang and Gansu should decrease plastic film input;and Gansu,Shanxi,and Inner Mongolia should cut pesticide input.Desirable output agricultural earnings should be increased in Qinghai and Tibet,and undesirable output(CO2 emissions)should be reduced in Inner Mongolia,Xinjiang,Gansu,and Shaanxi.Agricultural GTFP is influenced not only by internal production factors but also by external climate factors.To determine the influence of climate factors on GTFP in these provinces and autonomous regions,we used a Geographical Detector(Geodetector)model to analyze the influence of climate factors(temperature,precipitation,and sunshine duration)and identify the relationships between different climate factors and GTFP.We found that temperature played a significant role in the spatial heterogeneity of GTFP among provinces and autonomous regions in arid and semi-arid regions.For Xinjiang,Inner Mongolia,and Tibet,a suitable average annual temperature would be in the range of 7℃-9℃;for Gansu,Shanxi,and Ningxia,it would be 11℃-13℃;and for Shaanxi,it would be 15℃-17℃.Stable climatic conditions and more efficient production are prerequisites for the development of sustainable agriculture.Hence,in the agricultural production process,reducing the redundancy of input factors is the best way to reduce CO2 emissions and to maintain temperatures,thereby improving the agricultural GTFP.The significance of this study is that it explores the impact of both internal production factors and external climatic factors on the development of sustainable agriculture in arid and semi-arid regions,identifying an effective way forward for the arid and semi-arid regions of Northwest China.展开更多
The channel back-siltation problem has been restricting the development of channels,and its monitoring is limited by funds and natural conditions.Moreover,predicting the channel back-siltation situation in a timely an...The channel back-siltation problem has been restricting the development of channels,and its monitoring is limited by funds and natural conditions.Moreover,predicting the channel back-siltation situation in a timely and accurate manner is difficult.Hence,a numerical simulation of the back-siltation problem in the sea area near the channel is of great significance to the maintenance of a channel.In this study,the back siltation of a deep-water channel in the Lanshan Port area of the Port of Rizhao after dredging is predicted.This paper relies on the MIKE 21 software to establish the wave,tidal current,and sediment numerical models and uses measured data from two observation stations in the study area for verification.On this basis,taking one month as an example,the entire project channel was divided into five sections,and three observation points were set on each section.The results show that the area with offshore siltation is located in the northerly direction of the artificial anti-wave building.Siltation occurred on the northern seabed in the sea a little farther from the shore.Siltation occurred on the seabed surface far away from the shoreline,and with the increase in the distance from the shoreline,the amount of siltation in the south,center,and north became gradually closed,and the results can be used to guide actual engineering practices.This study will play a positive role in promoting the dredging project of Rizhao Lanshan Port.展开更多
It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency(CTGE)in the context of green development.We constructed a social development index that reflects the social ...It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency(CTGE)in the context of green development.We constructed a social development index that reflects the social benefits of transportation services,and incorporated it into the comprehensive transportation efficiency evaluation framework as an expected output.Based on the panel data of 30 regions in China from 2003-2018,the CTGE in China was measured using the slacks-based measure-data envelopment analysis(SBM-DEA)model.Further,the dynamic evolution trends of CTGE were determined using the spatial Markov model and exploratory spatio-temporal data analysis(ESTDA)technique from a spatio-temporal perspective.The results showed that the CTGE shows a U-shaped change trend but with an overall low level and significant regional differences.The state transition of CTGE has a strong spatial dependence,and there exists the phenomenon of“club convergence”.Neighbourhood background has a significant impact on the CTGE transition types,and the spatial spillover effect is pronounced.The CTGE has an obvious positive correlation and spatial agglomeration characteristics.The geometric characteristics of the LISA time path show that the evolution process of local spatial structure and local spatial dependence of China’s CTGE is stable,but the integration of spatial evolution is weak.The spatio-temporal transition results of LISA indicate that the CTGE has obvious transfer inertness and has certain path-dependence and spatial locking characteristics,which will become the major difficulty in improving the CTGE.展开更多
In recent decades,the exploration and development of marine oil and gas resources have increased significantly to meet the increasing energy demand of mankind.The Bohai Sea is a semi-closed continental sea that has a ...In recent decades,the exploration and development of marine oil and gas resources have increased significantly to meet the increasing energy demand of mankind.The Bohai Sea is a semi-closed continental sea that has a weak water exchange capacity and high ecological fragility.However,at present,more than 200 oil platforms have been built in the Bohai Sea,with more than 270 offshore oil pipelines having a length exceeding 1600 km.The oil spill pollution of offshore platforms has a great impact on the marine environment and ecosystems.Therefore,a comprehensive assessment of its risks is of great practical significance.This paper systematically constructs a comprehensive oil spill risk assessment model that combines the oil spill risk probability model and the ocean hydrodynamic model.This paper uses the Bohai Sea offshore pipeline as an example to assess its oil spill risk.The high-risk-value areas of the Bohai Sea offshore pipeline are mainly distributed at the bottom of Liaodong Bay,the bottom of Bohai Bay,near the Caofeidian area,and the northern part of the Yellow River Estuary.展开更多
Naturally occurring radium(^(223)Ra,^(224)Ra,^(226)Ra,and^(228)Ra)isotopes have been widely applied as geochemical tracers in marine environments,especially when estimating the submarine groundwater discharge(SGD).In ...Naturally occurring radium(^(223)Ra,^(224)Ra,^(226)Ra,and^(228)Ra)isotopes have been widely applied as geochemical tracers in marine environments,especially when estimating the submarine groundwater discharge(SGD).In this sense,the influencing factors and transport mechanism of radium isotope activity in aquifers can be key information for SGD estimation.This work evaluates the adsorption/desorption behavior of^(224)Ra and^(226)Ra in the solid-liquid phase through a leaching experiment and analysis of field data.The results suggested that radium isotope activity was positively correlated with salinity and grain size,in the case of abundant sediments.Through ion analysis,we found that the ions(Na^(+),Ca^(2+),Mg^(2+),and Ba^(2+))exchanged with radium isotopes in the process of transport.A 1-D reactive transport model was established to simulate the transport process of radium isotope in aquifers.The model successfully simulated the variation of radium isotope desorption activity with salinity and was subsequently verified in the field.This study contributes to the understanding of the geochemical behavior of radium isotopes in aquifers and provides guidance for selecting a suitable groundwater endmember in SGD estimation.展开更多
In this paper, we characterize the players’ behavior in the stock market by the repeated game model with asymmetric information. We show that the discount price process of stock is a martingale driven by Brownian mot...In this paper, we characterize the players’ behavior in the stock market by the repeated game model with asymmetric information. We show that the discount price process of stock is a martingale driven by Brownian motion, and give an endogenous explanation for the random fluctuation of stock price: the randomizations in the market is due to the randomizations in the strategy of the informed player which hopes to avoid revealing his private information. On this basis, through studying the corresponding option pricing problem furtherly, we can give the expression of function<em> φ</em>.展开更多
In the present study, galactosylated chitosan(Gal-CS) was conjugated with methoxy poly(ethylene glycol)(m PEG) as a hydrophilic group. The structure of Gal-CS-m PEG polymer was characterized and the nanoparticles(NPs)...In the present study, galactosylated chitosan(Gal-CS) was conjugated with methoxy poly(ethylene glycol)(m PEG) as a hydrophilic group. The structure of Gal-CS-m PEG polymer was characterized and the nanoparticles(NPs) were prepared using ironic gelation method. The study was designed to investigate the characteristics and functions of Gal-CS-m PEG NPs. The morphology of Gal-CS-m PEG NPs was observed by SEM and it was a compact and spherical shape. The size of the NPs was approximately 200 nm in diameter under the ideal process parameters. The interaction between Gal-CS-m PEG NPs and p DNA, and the protection of p DNA against DNase I and serum degradation by Gal-CS-m PEG NPs were evaluated. Agarose gel electrophoresis results showed that Gal-CS-m PEG NPs had strong interaction with p DNA at the weight ratio of 12:1, 4:1 and 2:1 and could protect p DNA from DNase I and serum degradation. Gal-CS-m PEG NPs exhibited high loading efficiency and sustainable in vitro release. The blood compatibility studies demonstrated that Gal-CS-m PEG NPs had superior compatibility with erythrocytes in terms of aggregation degree and hemolysis level. Gal-CS-m PEG NPs showed no cytotoxicity on L929 cells, which is a normal mouse connective tissue fibroblast, but showed inhibitory effects on the proliferation of Bel-7402 cells, which is a liver cancer cell line. In conclusion, Gal-CS-m PEG NP is a bio-safe and efficient gene carrier with potential application in gene delivery.展开更多
An internal gravity wave model was employed to simulate the generation of internal solitary waves(ISWs)over a sill by tidal flows.A westward shoaling pycnocline parameterization scheme derived from a three-parameter m...An internal gravity wave model was employed to simulate the generation of internal solitary waves(ISWs)over a sill by tidal flows.A westward shoaling pycnocline parameterization scheme derived from a three-parameter model was adopted,and then 14 numerical experiments were designed to investigate the influence of the pycnocline thickness,density difference across the pycnocline,westward shoaling isopycnal slope angle and pycnocline depth on the ISWs.When the pycnocline thickness on both sides of the sill increases,the total barotropic kinetic energy,total baroclinic energy and ratio of baroclinic kinetic energy(KE)to available potential energy(APE)decrease,whilst the depth of isopycnal undergoing maximum displacement and ratio of baroclinic energy to barotropic energy increase.When the density difference on both sides of the sill decreases synchronously,the total barotropic kinetic energy,ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the depth of isopycnal undergoing maximum displacement increases.When the westward shoaling isopycnal slope angle increases,the total baroclinic energy increases whilst the depth of turning point almost remains unchanged.When the depth of westward shoaling pycnocline on both sides of the sill reduces,the ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the total barotropic kinetic energy and ratio of KE to APE increase.When one of the above four different influencing factors was increased by 10%while the other factors keep unchanged,the amplitude of the leading soliton in ISW Packet A was decreased by 2.80%,7.47%,3.21%and 6.42%respectively.The density difference across the pycnocline and the pycnocline depth are the two most important factors in affecting the characteristics and energetics of ISWs.展开更多
Digital economy has become a key engine for China’s economic development,bringing new historical opportunities for marine inclusive green total factor productivity(Migtfp)improvement.This paper analyzes the effect an...Digital economy has become a key engine for China’s economic development,bringing new historical opportunities for marine inclusive green total factor productivity(Migtfp)improvement.This paper analyzes the effect and mechanism of digital economy on Migtfp based on the sample data of Migtfp,its decomposition index and digital economy index of 11 provinces(autonomous regions and municipalities directly under the central government)along the coast of China from 2011 to 2021.The results show that:(1)In time,the Migtfp and digital economy index of China’s coastal areas basically realized steady improvement during the study period.Spatially,the regional differences in the Migtfp and digital economy index are obvious,with Migtfp being highest in Guangdong and lowest in Hebei,and digital economy index being highest in Guangdong and lowest in Hainan.(2)The relationship between the digital economy and Migtfp shows a“U”-shaped relationship of inhibition followed by promotion,which is mainly realized through Mec.Mechanism analysis shows that marine technological innovation and capital factor mismatch are non-linear transmission mechanisms of the digital economy affecting Migtfp,but the mechanism of labor factor mismatch is not valid.(3)Heterogeneity analysis reveals that there is a“U”shaped relationship between the digital economy and Migtfp in regions with higher levels of the digital economy,regions with lower levels of industrial structure,and the northern and eastern marine economic circles.The results of the study can provide insights for China to formulate effective policies to enhance the Migtfp in order to realize the high-quality development of the marine economy.展开更多
Flexible phase change materials(PCMs)have become increasingly critical to address the demand for thermal management in electronic technologies and energy conversion.However,their application remains challenging becaus...Flexible phase change materials(PCMs)have become increasingly critical to address the demand for thermal management in electronic technologies and energy conversion.However,their application remains challenging because of their rigidity,liquid leakage,and insufficient thermal conductivity.Herein,flexible glutamic acid@natural rubber/paraffin wax(PW)/carbon nanotubes-graphene nanoplatelets(GNR/PW/CGNP)phase change composites with high thermal conductivity,excellent shape stability,and recyclability were reported.Zn^(2+)-based dynamic crosslinking was constructed through the reaction of zinc acetate and carboxyl groups on glutamic acid@natural rubber(GNR),which was used as a flexible matrix to physically blend with paraffin wax/carbon nanotubes/graphene nanoplatelets(PW/CGNP)to achieve uniform dispersion of PW/CGNP,continuous thermal conductivity networks,and good encapsulation of PW.The GNR/PW/CGNP composites showed excellent mechanical strength,flexibility,and recycling ability,and effective encapsulation prevented the outflow of melted PW during the phase transition.Also,the phase change enthalpy could attain 111.1 J/g with a higher thermal conductivity of 1.055 W/m K,428%higher than that of pure PW owing to the formation of efficient thermal conductive pathways,which exhibited outstanding thermal management performance and superior temperature control behavior in electronic devices.The developed flexible composite PCMs may open new possibilities for next-generation flexible thermal management electronics.展开更多
基金National Social Science Fund of China,No.24BTJ037Significant Project of the National Social Science Foundation of China,No.23&ZD102+1 种基金The Key Research Base for Philosophy and Social Sciences in Hangzhou:ESG and Sustainable Development Research Center,No.25JD053Zhejiang Provincial Statistical Scientific Research Project,No.25TJZZ12。
文摘Establishing a Regional Marine Innovation Ecosystem(RMIE)is crucial for advancing China’s maritime power strategy.Concurrently,developing a competitive RMIE serves as a strategic lever to enhance the global competitiveness of China’s marine science sector.However,research on the competitiveness of RMIE is limited.To this end,this study constructs an evaluation index system based on ecological niche theory to assess the competitiveness of RMIE in China from 2008 to 2020.The findings indicate generally fluctuating upward trends in RMIE’s competitiveness,with Shandong,Jiangsu,and Guangdong showing relatively strong positions.Notably,there are significant intra-regional imbalances and inter-regional asynchrony in RMIE’s competitiveness across China’s three major marine economic circles.Recognizing that forecasting RMIE competitiveness can inform policy formulation,this paper proposes a systematic multivariate grey interval prediction model that incorporates spatial proximity effects.This model effectively captures the interval and uncertainty characteristics of RMIE’s competitiveness while considering spatial relationships among regions.Results from comparative analysis,robustness tests,and sensitivity analysis demonstrate its superior applicability and forecasting accuracy.Additionally,interval forecasts and scenario analyses suggest that RMIE competitiveness will maintain stable growth,although unbalanced and unsynchronized development is likely to persist.Overall,the approach developed for evaluating and forecasting RMIE competitiveness offers valuable insights for effective policy formulation.
基金National Natural Science Foundation of China,No.42276231,No.41871112The Open Research Fund of the State Key Laboratory of Coastal and Marine Engineering,No.LP2518。
文摘Assessing the carbon sink potential of marine aquaculture is critical to fostering sustainable marine economic development and achieving carbon neutrality.This study evaluates the carbon sink potential of four nearshore aquaculture systems in China:floating raft,net cage,pond,and tidal flat.China’s coastal aquaculture shows a dramatic potential range from−5401.28×10^(4)t to 84.65×10^(4)t,acting as both a carbon sink and a source.Floating raft(11.19×10^(4)t to 105.65×10^(4)t)and tidal flat(42.83×10^(4)t to 114.35×10^(4)t)are net carbon sinks.In contrast,net cage(−427.39×10^(4)t to−4.26×10^(4)t)and pond(−5027.91×10^(4)t to−131.09×10^(4)t)are significant net carbon sources.This heterogeneity is driven by differences in species,feed inputs,energy consumption,and management practices.The results highlight the need for targeted low-carbon technologies in high-emission systems to maximize carbon sequestration and mitigate their environmental impacts.This study provides a scientific basis for optimizing carbon management and offers insights for global sustainable aquaculture and carbon neutrality.
基金Under the auspices of the National Natural Science Foundation of China(No.41976207,42076222,42071159)。
文摘High-quality development of marine fisheries provides an important advantage for China to build itself into a maritime power and implement the Blue Granary Plan effectively.Based on the concepts of‘new development’,‘food security’,and the six dimensions of‘openness,innovation,coordination,green,sharing,and security’,in this study,we established an evaluation index system for the high-quality development of China’s marine fishery sector.We applied the entropy method to evaluate the high-quality development level of China’s marine fishery sector from 2000 to 2016 and explored its spatial and temporal evolution rules.Our results indicated that:1)from 2000 to 2016,China’s marine fishery sector was in the primary stage of high-quality development;2)spatially,the highquality development of marine fisheries showed an upward trend in all provinces,autonomous regions,and municipalities in the country(not including Hong Kong,Macao and Taiwan of China),and with time,the distribution pattern changed from single to multi-polarization;3)temporally,the development level of high-quality marine fisheries fluctuated during the study period.From 2000 to 2010,the growth rate in openness was relatively slow,but after 2010,it increased rapidly.Notably,innovation is the driving force for high-quality development.The green and security factors provide a solid guarantee for high-quality development.In the high-quality development of a region,economic development is better coordinated,and the distribution of benefits is more inclusive.This study provides a theoretical basis to formulate effective marine fishery policies for the high-quality development of the marine fishery sector in China.Exploring the high-quality development and evolution process of marine fishery is conducive to promoting the sustainable development of marine fishery industry,ensuring marine fishery food security,and alleviating global food crisis.
基金supported in part by National Key R&D Program of China(2022YFB4501200),National Natural Science Foundation of China(62332018)Science and Technology Program(2024NSFTD0031,2024YFHZ0339 and 2025ZNSFSC0497).
文摘The performance of data restore is one of the key indicators of user experience for backup storage systems.Compared to the traditional offline restore process,online restore reduces downtime during backup restoration,allowing users to operate on already restored files while other files are still being restored.This approach improves availability during restoration tasks but suffers from a critical limitation:inconsistencies between the access sequence and the restore sequence.In many cases,the file a user needs to access at a given moment may not yet be restored,resulting in significant delays and poor user experience.To this end,we present Histore,which builds on the user’s historical access sequence to schedule the restore sequence,in order to reduce users’access delayed time.Histore includes three restore approaches:(i)the frequency-based approach,which restores files based on historical file access frequencies and prioritizes ensuring the availability of frequently accessed files;(ii)the graph-based approach,which preferentially restores the frequently accessed files as well as their correlated files based on historical access patterns,and(iii)the trie-based approach,which restores particular files based on both users’real-time and historical access patterns to deduce and restore the files to be accessed in the near future.We implement a prototype of Histore and evaluate its performance from multiple perspectives.Trace-driven experiments on two datasets show that Histore significantly reduces users’delay time by 4-700×with only 1.0%-14.5%additional performance overhead.
基金Under the auspices of the National Natural Science Foundation of China(No.42076222)。
文摘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.
基金Under the auspices of the Key Research Base of Humanities and Social Sciences of the Ministry of Education of China(No.22JJD790029)。
文摘Data on discrete,isolated attributes of the marine economy are often used in traditional marine economic research.However,as the focus of urban research shifts from internal static attributes to external dynamic linkages,the importance of marine economic net-work research is beginning to emerge.The construction of the marine economic network in China’s coastal areas is necessary to change the flow of land and sea resources and optimize regional marine economic development.Employing data from headquarters and branches of sea-related A-share listed enterprises to construct the marine economic network in China,we use social network analysis(SNA)to discuss the characteristics of its evolution as of 2010,2015,and 2020 and its governance.The following results were obtained.1)In terms of topological characteristics,the scale of the marine economic network in China’s coastal areas has accelerated and expan-ded,and the connections have become increasingly close;thus,this development has complex network characteristics.2)In terms of spatial structure,the intensity of the connection fluctuates and does not form stable development support;the group structure gradually becomes clear,but the overall pattern is fragmented;there are spatial differences in marine economic agglomeration radiation;the radi-ation effect of the eastern marine economic circle is obvious;and the polarization effect of northern and southern marine economic circles is significant.On this basis,we construct a framework for the governance of a marine economic network with the market,the government,and industry as the three governing bodies.By clarifying the driving factors and building objectives of marine economic network construction,this study aims to foster the high-quality development of China’s marine economy.
基金Under the auspices of National Natural Science Foundation of China(No.42471221)Major Projects of Key Research Base of Humanities and Social Sciences of Ministry of Education(No.22JJD790031)。
文摘The complex relationship between humans and nature plays a key role in shaping geographic landscapes.This study examines how tourism transforms island landscapes into marketable commodities,focusing on Guanglu Island in China from 2002–2025 through the lens of Actor-Network Theory(ANT).The findings reveal three main insights:1)commodification involves reimagining natural landscapes,digitizing them for broader appeal,and integrating them into tourist consumption.2)This process reshapes original landscapes into four interconnected forms:material landscapes,fluid landscapes,virtual landscapes,and psychological landscapes.3)Multiple actors drive commodification:the island’s natural conditions provide foundation and influence concrete ways of commodification,local government is deeply involved through planning and regulating tourism development,tourism practitioners adapt services to market demands,and tourist preferences guide the direction of commercialization.By analyzing the roles of both human and non-human actors,this research highlights how tourism redefines island landscapes while emphasizing the active influence of nature itself in these transformations.The findings reveal the geographical attributes of landscape commodification process and the multidimensionality and complexity of its impacts,thereby providing valuable insights for the sustainable development of island tourism.
基金National Natural Science Foundation of ChinaNo.72174035+5 种基金The National Key Research and Development ProjectNo.2023YFB4302200111 Project of ChinaNo.B20082The Talent Planning in DalianNo.2022RG05。
文摘The evolution mechanism of railway transportation network nodes driven by sea-rail intermodal transport(SRIT),a globally prevalent logistics method,has not been thoroughly investigated.From the perspective of SRIT,this study constructed a framework for understanding the evolution of railway container transport network nodes using Northeast China from 2013 to 2020 as a case study.It leverages proprietary data from 95306 Railway Freight E-commerce Platform.By employing the hybrid EWM-GA-TOPSIS model,complex network analysis,modified gravity model,and correlation and regression analyses,this study delves into the spatiotemporal patterns and dynamic transformations of railway container freight stations(RCFS).Finally,the long-term relationship between the RCFS and SRIT is explored.The results indicate that the spatial and temporal analysis of the RCFS in Northeast China from 2013 to 2020 revealed a clear polarisation trend,with the top-ranked stations mainly concentrated near ports and important transportation hubs.Additionally,the RCFS exhibited an expansionary trend;however,its development was uneven,and there was a significant increase in the number of new stations compared to abandoned stations,indicating an overall positive growth tendency.Moreover,the intensity of the SRIT at the RCFS in Northeast China notably increased.A significant positive linear relationship exists between SRIT and the freight capacity of all stations.A relatively pronounced correlation was observed for high-intensity stations,whereas a relatively weak correlation was observed for low-intensity stations.This study not only provides an effective framework for future research on RCFS within the context of SRIT but also serves as a scientific reference for promoting the implementation of the national strategy for multimodal transportation.
基金financially supported by the China Postdoctoral Science Foundation(No.2024M751205)the Natural Science Foundation of Jiangsu Province(JSNSF)(No.BK20230694)。
文摘Poly(vinyl alcohol)(PVA)hydrogels have garnered significant attention for tissue engineering,wound dressing,and electronic skin sensing applications.However,their poor mechanical performance severely restricts their multifunctional application in many scenarios.To address this limitation,PVA/tannic acid(TA)@carbon nanotubes(PVA/TA@CNTs)composite hydrogels with triple crosslinking networks were prepared through freezing-thawing and the solvent-induced shrinkage method,utilizing tannic acid-carbon nanotubes(TA@CNTs)as reinforcing units and a Ca^(2+)crosslinking strategy.The enhanced interfacial networks consisting of PVA crystalline domains,hydrogen bonding,and metal coordination endowed the composite hydrogel with a high mechanical strength,excellent flexibility,and fracture toughness,accompanied by a significant increase in crystallinity.The tensile strength and fracture toughness of the composite hydrogel reached up to about 7.0 MPa and 17.0MJ/m^(3),which were roughly 8 and 10 times higher than those of neat PVA hydrogel,respectively.The composite hydrogel demonstrated good cytocompatibility,significantly addressing the challenge of balancing structural reinforcement with biosafety in hydrogels.This methodology establishes a rational design for fabricating mechanically robust yet tough PVA hydrogels for biomedical applications.
基金supported by the Key Laboratory of Coastal Science and Integrated Management,Ministry of Natural Resources(No.2022COSIMQ002)the Shandong Provincial Social Science Planning Research Project(No.22CXSXJ15)+1 种基金the Guangxi Key Laboratory of Marine Environmental Science,Guangxi Academy of Sciences(No.GXKLHY21-04)the Hainan Province Marxism Project General Program(No.2023HNMGC03).
文摘Storm surge events(SSEs)involve multiple hazard-causing factors,such as surges,extreme rainfall,strong winds,waves,and ocean currents,which have destructive impacts on coastal regions.For a quantitative multi-hazard assessment of SSEs,this study introduced the concept of the storm surge event seawater-atmosphere system(SSE-SAS)and proposed the system energy equivalence(SEE)model from a systemic energy perspective.SEE was obtained by employing a parameterization approach,and the hazard index(HI)and the concept of most significant hazard(MSH)were adopted to evaluate the severity of SSE-SAS.SEE at five stations in the Shandong Peninsula was calculated from 2005 to 2019,and probability analysis and hazard assessment were further conducted.Results show that the SEE of SSE-SAS ranges from 0.029×10^(3) to 30.418×10^(3) J/m^(2),and it exhibits an insignificant decreasing trend from 2005 to 2019.The SEE of SSE-SAS in the west of the Shandong Peninsula is greater than that in the east.Moreover,storm waves,storm surges,and storm rainfall are the major contributors to SEE,which exhibit different spatial patterns and characters in different SSE-SAS types.The HI of SSE-SAS at five stations is no more than medium hazard level,with MSH at return periods of 2-to 4-year level.This study provides a new approach for quantifying multi-hazard SSEs,which offers scientific insights for regional multi-hazard risk reduction and mitigation efforts.
基金the National Natural Science Foundation of China(71974176,71473233)the Chinese Academy of Sciences(CAS)"Light of West China"Program(2018-XBQNXZ-B-017)+1 种基金the High Level Talent Introduction Project of Xinjiang Uygur Autonomous Region(Y942171)the"High Talents Program of Xinjiang Institute of Ecology and Geography,CAS"(Y871171).
文摘There are eight provinces and autonomous regions(Gansu Province,Ningxia Hui Autonomous Region,Xinjiang Uygur Autonomous Region,Inner Mongolia Autonomous Region,Tibet Autonomous Region,Qinghai Province,Shanxi Province,and Shaanxi Province)in Northwest China,most areas of which are located in arid and semi-arid regions(northwest of the 400 mm precipitation line),accounting for 58.74%of the country's land area and sustaining approximately 7.84×10^6 people.Because of drought conditions and fragile ecology,these regions cannot develop agriculture at the expense of the environment.Given the challenges of global warming,the green total factor productivity(GTFP),taking CO2 emissions as an undesirable output,is an effective index for measuring the sustainability of agricultural development.Agricultural GTFP can be influenced by both internal production factors(labor force,machinery,land,agricultural plastic film,diesel,pesticide,and fertilizer)and external climate factors(temperature,precipitation,and sunshine duration).In this study,we used the Super-slacks-based measure(Super-SBM)model to measure agricultural GTFP during the period 2000-2016 at the regional level.Our results show that the average agricultural GTFP of most provinces and autonomous regions in arid and semi-arid regions underwent a fluctuating increase during the study period(2000-2016),and the fluctuation was caused by the production factors(input and output factors).To improve agricultural GTFP,Shaanxi,Shanxi,and Gansu should reduce agricultural labor force input;Shaanxi,Inner Mongolia,Gansu,and Shanxi should decrease machinery input;Shaanxi,Inner Mongolia,Xinjiang,and Shanxi should reduce fertilizer input;Shaanxi,Xinjiang,Gansu,and Ningxia should reduce diesel input;Xinjiang and Gansu should decrease plastic film input;and Gansu,Shanxi,and Inner Mongolia should cut pesticide input.Desirable output agricultural earnings should be increased in Qinghai and Tibet,and undesirable output(CO2 emissions)should be reduced in Inner Mongolia,Xinjiang,Gansu,and Shaanxi.Agricultural GTFP is influenced not only by internal production factors but also by external climate factors.To determine the influence of climate factors on GTFP in these provinces and autonomous regions,we used a Geographical Detector(Geodetector)model to analyze the influence of climate factors(temperature,precipitation,and sunshine duration)and identify the relationships between different climate factors and GTFP.We found that temperature played a significant role in the spatial heterogeneity of GTFP among provinces and autonomous regions in arid and semi-arid regions.For Xinjiang,Inner Mongolia,and Tibet,a suitable average annual temperature would be in the range of 7℃-9℃;for Gansu,Shanxi,and Ningxia,it would be 11℃-13℃;and for Shaanxi,it would be 15℃-17℃.Stable climatic conditions and more efficient production are prerequisites for the development of sustainable agriculture.Hence,in the agricultural production process,reducing the redundancy of input factors is the best way to reduce CO2 emissions and to maintain temperatures,thereby improving the agricultural GTFP.The significance of this study is that it explores the impact of both internal production factors and external climatic factors on the development of sustainable agriculture in arid and semi-arid regions,identifying an effective way forward for the arid and semi-arid regions of Northwest China.
基金The study is supported by the Guangxi Key Laboratory of Marine Environmental Science,Guangxi Academy of Sciences(No.GXKLHY21-04)the Special Funds for Fun-damental Scientific Research Operation of Central Universities(No.202113011)+2 种基金the Shandong Provincial Social Science Planning Research Youth Project(No.21DSHJ2)NSFC-Shandong Joint Fund(No.U1706215)the Tian-jin Philosophy and Social Science Planning Project of China(No.TJKS20XSX-015).
文摘The channel back-siltation problem has been restricting the development of channels,and its monitoring is limited by funds and natural conditions.Moreover,predicting the channel back-siltation situation in a timely and accurate manner is difficult.Hence,a numerical simulation of the back-siltation problem in the sea area near the channel is of great significance to the maintenance of a channel.In this study,the back siltation of a deep-water channel in the Lanshan Port area of the Port of Rizhao after dredging is predicted.This paper relies on the MIKE 21 software to establish the wave,tidal current,and sediment numerical models and uses measured data from two observation stations in the study area for verification.On this basis,taking one month as an example,the entire project channel was divided into five sections,and three observation points were set on each section.The results show that the area with offshore siltation is located in the northerly direction of the artificial anti-wave building.Siltation occurred on the northern seabed in the sea a little farther from the shore.Siltation occurred on the seabed surface far away from the shoreline,and with the increase in the distance from the shoreline,the amount of siltation in the south,center,and north became gradually closed,and the results can be used to guide actual engineering practices.This study will play a positive role in promoting the dredging project of Rizhao Lanshan Port.
基金National Key Research and Development Program of China(2019YFB1600400)National Natural Science Foundation of China(72174035)+2 种基金National Natural Science Foundation of China(71774018)Liaoning Revitalization Talents Program(XLYC2008030)Liaoning Provincial Natural Science Foundation Shipping Joint Foundation Program(2020-HYLH-20)。
文摘It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency(CTGE)in the context of green development.We constructed a social development index that reflects the social benefits of transportation services,and incorporated it into the comprehensive transportation efficiency evaluation framework as an expected output.Based on the panel data of 30 regions in China from 2003-2018,the CTGE in China was measured using the slacks-based measure-data envelopment analysis(SBM-DEA)model.Further,the dynamic evolution trends of CTGE were determined using the spatial Markov model and exploratory spatio-temporal data analysis(ESTDA)technique from a spatio-temporal perspective.The results showed that the CTGE shows a U-shaped change trend but with an overall low level and significant regional differences.The state transition of CTGE has a strong spatial dependence,and there exists the phenomenon of“club convergence”.Neighbourhood background has a significant impact on the CTGE transition types,and the spatial spillover effect is pronounced.The CTGE has an obvious positive correlation and spatial agglomeration characteristics.The geometric characteristics of the LISA time path show that the evolution process of local spatial structure and local spatial dependence of China’s CTGE is stable,but the integration of spatial evolution is weak.The spatio-temporal transition results of LISA indicate that the CTGE has obvious transfer inertness and has certain path-dependence and spatial locking characteristics,which will become the major difficulty in improving the CTGE.
基金supported by the Special Funds for Fundamental Scientific Research Operation of Central Universities(No.202113011)the Guangxi Key Laboratory of Marine Environmental Science,Guangxi Academy of Sciences(No.GXKLHY21-04)+2 种基金the Shandong Provincial Social Science Planning Research Youth Project(No.21DSHJ2)the General Project of National Social Science Fund for Research on the Ideological and Political Courses in Colleges and Universities(No.21VSZ102)the Ministry of Natural Resources Departmental Budget Project‘Research on the Policy and Operation System of the Control System for Land and Space Use’(No.121107000000190014)。
文摘In recent decades,the exploration and development of marine oil and gas resources have increased significantly to meet the increasing energy demand of mankind.The Bohai Sea is a semi-closed continental sea that has a weak water exchange capacity and high ecological fragility.However,at present,more than 200 oil platforms have been built in the Bohai Sea,with more than 270 offshore oil pipelines having a length exceeding 1600 km.The oil spill pollution of offshore platforms has a great impact on the marine environment and ecosystems.Therefore,a comprehensive assessment of its risks is of great practical significance.This paper systematically constructs a comprehensive oil spill risk assessment model that combines the oil spill risk probability model and the ocean hydrodynamic model.This paper uses the Bohai Sea offshore pipeline as an example to assess its oil spill risk.The high-risk-value areas of the Bohai Sea offshore pipeline are mainly distributed at the bottom of Liaodong Bay,the bottom of Bohai Bay,near the Caofeidian area,and the northern part of the Yellow River Estuary.
基金The Joint Funds of the National Natural Science Foundation of China under contract Nos U22A20580 and U2106203the National Natural Science Foundation of China under contract No.41706067the Open Project Program of Key Laboratory of Ecological Warning,Protection&Restoration for Bohai Sea,Ministry of Natural Resources under contract No.2022108.
文摘Naturally occurring radium(^(223)Ra,^(224)Ra,^(226)Ra,and^(228)Ra)isotopes have been widely applied as geochemical tracers in marine environments,especially when estimating the submarine groundwater discharge(SGD).In this sense,the influencing factors and transport mechanism of radium isotope activity in aquifers can be key information for SGD estimation.This work evaluates the adsorption/desorption behavior of^(224)Ra and^(226)Ra in the solid-liquid phase through a leaching experiment and analysis of field data.The results suggested that radium isotope activity was positively correlated with salinity and grain size,in the case of abundant sediments.Through ion analysis,we found that the ions(Na^(+),Ca^(2+),Mg^(2+),and Ba^(2+))exchanged with radium isotopes in the process of transport.A 1-D reactive transport model was established to simulate the transport process of radium isotope in aquifers.The model successfully simulated the variation of radium isotope desorption activity with salinity and was subsequently verified in the field.This study contributes to the understanding of the geochemical behavior of radium isotopes in aquifers and provides guidance for selecting a suitable groundwater endmember in SGD estimation.
文摘In this paper, we characterize the players’ behavior in the stock market by the repeated game model with asymmetric information. We show that the discount price process of stock is a martingale driven by Brownian motion, and give an endogenous explanation for the random fluctuation of stock price: the randomizations in the market is due to the randomizations in the strategy of the informed player which hopes to avoid revealing his private information. On this basis, through studying the corresponding option pricing problem furtherly, we can give the expression of function<em> φ</em>.
基金the National ‘12th Five-year’ High technology Research and Development Program of China (No. 2014AA093605)the Zhejiang Science and Technology Project (No. 2013C 33192)
文摘In the present study, galactosylated chitosan(Gal-CS) was conjugated with methoxy poly(ethylene glycol)(m PEG) as a hydrophilic group. The structure of Gal-CS-m PEG polymer was characterized and the nanoparticles(NPs) were prepared using ironic gelation method. The study was designed to investigate the characteristics and functions of Gal-CS-m PEG NPs. The morphology of Gal-CS-m PEG NPs was observed by SEM and it was a compact and spherical shape. The size of the NPs was approximately 200 nm in diameter under the ideal process parameters. The interaction between Gal-CS-m PEG NPs and p DNA, and the protection of p DNA against DNase I and serum degradation by Gal-CS-m PEG NPs were evaluated. Agarose gel electrophoresis results showed that Gal-CS-m PEG NPs had strong interaction with p DNA at the weight ratio of 12:1, 4:1 and 2:1 and could protect p DNA from DNase I and serum degradation. Gal-CS-m PEG NPs exhibited high loading efficiency and sustainable in vitro release. The blood compatibility studies demonstrated that Gal-CS-m PEG NPs had superior compatibility with erythrocytes in terms of aggregation degree and hemolysis level. Gal-CS-m PEG NPs showed no cytotoxicity on L929 cells, which is a normal mouse connective tissue fibroblast, but showed inhibitory effects on the proliferation of Bel-7402 cells, which is a liver cancer cell line. In conclusion, Gal-CS-m PEG NP is a bio-safe and efficient gene carrier with potential application in gene delivery.
基金The Key Research Program of Frontier SciencesChinese Academy of Sciences(CAS)under contract No.QYZDJSSW-DQC034+6 种基金the Talent Project from Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0304the National Natural Science Foundation of China(NSFC)under contract Nos 41521005 and 62071207the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Natural Science Foundation of Huai Hai Institute of Technology under contract No.Z2017006the Project from Department of Natural Resources of Guangdong Province under contract No.(2020)017the Open Project of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanolog,CAS under contract No.LTO1702Postgraduate Research&Practice Innovation Program of Jiangsu Province under contract No.SJCX190963。
文摘An internal gravity wave model was employed to simulate the generation of internal solitary waves(ISWs)over a sill by tidal flows.A westward shoaling pycnocline parameterization scheme derived from a three-parameter model was adopted,and then 14 numerical experiments were designed to investigate the influence of the pycnocline thickness,density difference across the pycnocline,westward shoaling isopycnal slope angle and pycnocline depth on the ISWs.When the pycnocline thickness on both sides of the sill increases,the total barotropic kinetic energy,total baroclinic energy and ratio of baroclinic kinetic energy(KE)to available potential energy(APE)decrease,whilst the depth of isopycnal undergoing maximum displacement and ratio of baroclinic energy to barotropic energy increase.When the density difference on both sides of the sill decreases synchronously,the total barotropic kinetic energy,ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the depth of isopycnal undergoing maximum displacement increases.When the westward shoaling isopycnal slope angle increases,the total baroclinic energy increases whilst the depth of turning point almost remains unchanged.When the depth of westward shoaling pycnocline on both sides of the sill reduces,the ratio of baroclinic energy to barotropic energy and total baroclinic energy decrease,whilst the total barotropic kinetic energy and ratio of KE to APE increase.When one of the above four different influencing factors was increased by 10%while the other factors keep unchanged,the amplitude of the leading soliton in ISW Packet A was decreased by 2.80%,7.47%,3.21%and 6.42%respectively.The density difference across the pycnocline and the pycnocline depth are the two most important factors in affecting the characteristics and energetics of ISWs.
基金supported by the Humanities and Social Sciences Research base of Ministry of Education(Grant No.22JJD790029).
文摘Digital economy has become a key engine for China’s economic development,bringing new historical opportunities for marine inclusive green total factor productivity(Migtfp)improvement.This paper analyzes the effect and mechanism of digital economy on Migtfp based on the sample data of Migtfp,its decomposition index and digital economy index of 11 provinces(autonomous regions and municipalities directly under the central government)along the coast of China from 2011 to 2021.The results show that:(1)In time,the Migtfp and digital economy index of China’s coastal areas basically realized steady improvement during the study period.Spatially,the regional differences in the Migtfp and digital economy index are obvious,with Migtfp being highest in Guangdong and lowest in Hebei,and digital economy index being highest in Guangdong and lowest in Hainan.(2)The relationship between the digital economy and Migtfp shows a“U”-shaped relationship of inhibition followed by promotion,which is mainly realized through Mec.Mechanism analysis shows that marine technological innovation and capital factor mismatch are non-linear transmission mechanisms of the digital economy affecting Migtfp,but the mechanism of labor factor mismatch is not valid.(3)Heterogeneity analysis reveals that there is a“U”shaped relationship between the digital economy and Migtfp in regions with higher levels of the digital economy,regions with lower levels of industrial structure,and the northern and eastern marine economic circles.The results of the study can provide insights for China to formulate effective policies to enhance the Migtfp in order to realize the high-quality development of the marine economy.
基金financially supported by the China Postdoctoral Science Foundation(No.2024M751205)。
文摘Flexible phase change materials(PCMs)have become increasingly critical to address the demand for thermal management in electronic technologies and energy conversion.However,their application remains challenging because of their rigidity,liquid leakage,and insufficient thermal conductivity.Herein,flexible glutamic acid@natural rubber/paraffin wax(PW)/carbon nanotubes-graphene nanoplatelets(GNR/PW/CGNP)phase change composites with high thermal conductivity,excellent shape stability,and recyclability were reported.Zn^(2+)-based dynamic crosslinking was constructed through the reaction of zinc acetate and carboxyl groups on glutamic acid@natural rubber(GNR),which was used as a flexible matrix to physically blend with paraffin wax/carbon nanotubes/graphene nanoplatelets(PW/CGNP)to achieve uniform dispersion of PW/CGNP,continuous thermal conductivity networks,and good encapsulation of PW.The GNR/PW/CGNP composites showed excellent mechanical strength,flexibility,and recycling ability,and effective encapsulation prevented the outflow of melted PW during the phase transition.Also,the phase change enthalpy could attain 111.1 J/g with a higher thermal conductivity of 1.055 W/m K,428%higher than that of pure PW owing to the formation of efficient thermal conductive pathways,which exhibited outstanding thermal management performance and superior temperature control behavior in electronic devices.The developed flexible composite PCMs may open new possibilities for next-generation flexible thermal management electronics.
