Deep sea,with rich oil,gas,and mineral resources,plays an increasingly crucial role in scientific and industrial realms.However,the highly corrosive feature of deep sea hinders further exploration and development,whic...Deep sea,with rich oil,gas,and mineral resources,plays an increasingly crucial role in scientific and industrial realms.However,the highly corrosive feature of deep sea hinders further exploration and development,which requires metal materials with robust corrosion resistance.This review covers an in-depth and all-around overview of the up-to-date advances in corrosion and protection of metals in deep-sea environment.Firstly,the unique characteristics of deep-sea environment are summarized in detail.Subsequently,the corrosion performances of metals in both in situ and simulated deep-sea environments are illustrated systematically.Furthermore,corrosion prevent strategies of metals,including sacrificial anode protection,organic coatings,as well as coatings achieved by physical vapor deposition(PVD coatings),are highlighted.Finally,we outline current challenges and development trends of corrosion and protection of metals in deep-sea environment in the future.The purpose of this review is not only to summarize the recent progress on metal corrosion and protection in deep sea,but also to aid us in understanding them more comprehensively and deeply in a short time,so as to boost their fast development.展开更多
Natural gas hydrate(NGH)has a bright future as a clean energy source with huge reserves.Coring is one of the most direct methods for NGH exploration and research.Preserving the in-situ properties of the core as much a...Natural gas hydrate(NGH)has a bright future as a clean energy source with huge reserves.Coring is one of the most direct methods for NGH exploration and research.Preserving the in-situ properties of the core as much as possible during the coring process is crucial for the assessment of NGH resources.However,most existing NGH coring techniques cannot preserve the in-situ temperature of NGH,leading to distortion of the physical properties of the obtained core,which makes it difficult to effectively guide NGH exploration and development.To overcome this limitation,this study introduces an innovative active temperature-preserved coring method for NGH utilizing phase change materials(PCM).An active temperature-preserved corer(ATPC)is designed and developed,and an indoor experimental system is established to investigate the heat transfer during the coring process.Based on the experimental results under different environment temperatures,a heat transfer model for the entire ATPC coring process has been established.The indoor experimental results are consistent with the theoretical predictions of the heat transfer model,confirming its validity.This model has reconstructed the temperature changes of the NGH core during the coring process,demonstrating that compared to the traditional coring method with only passive temperature-preserved measures,ATPC can effectively reduce the core temperature by more than 5.25℃.With ATPC,at environment temperatures of 15,20,25,and 30℃,the duration of low-temperature state for the NGH core is 53.85,32.87,20.32,and 11.83 min,respectively.These findings provide new perspectives on temperature-preserving core sampling in NGH and provide technical support for exploration and development in NGH.展开更多
The chirp sub-bottom profiler,for its high resolution,easy accessibility and cost-effectiveness,has been widely used in acoustic detection.In this paper,the acoustic impedance and grain size compositions were obtained...The chirp sub-bottom profiler,for its high resolution,easy accessibility and cost-effectiveness,has been widely used in acoustic detection.In this paper,the acoustic impedance and grain size compositions were obtained based on the chirp sub-bottom profiler data collected in the Chukchi Plateau area during the 11th Arctic Expedition of China.The time-domain adaptive search matching algorithm was used and validated on our established theoretical model.The misfit between the inversion result and the theoretical model is less than 0.067%.The grain size was calculated according to the empirical relationship between the acoustic impedance and the grain size of the sediment.The average acoustic impedance of sub-seafloor strata is 2.5026×10^(6) kg(s m^(2))^(-1)and the average grain size(θvalue)of the seafloor surface sediment is 7.1498,indicating the predominant occurrence of very fine silt sediment in the study area.Comparison of the inversion results and the laboratory measurements of nearby borehole samples shows that they are in general agreement.展开更多
Based on the fifth-order Stokes regular wave theory, a simplified model for extreme-wave kinematics in deep sea was developed. In this model, from the wave records the average of two neighboring wave periods for the e...Based on the fifth-order Stokes regular wave theory, a simplified model for extreme-wave kinematics in deep sea was developed. In this model, from the wave records the average of two neighboring wave periods for the extreme crest or trough was defined as the period of the Stokes wave by the up and down zero-crossing methods. Then the input wave amplitude was deduced by substituting the wave period and extreme crest or trough into the expression for the fifth-order Stokes wave elevation. Thus the corresponding formula for the wave velocity can be used to describe kinematics beneath the extreme wave. By comparison with the published numerical models and experimental data, the proposed model is validated to be able to calculate the extreme wave velocity rather easily and accurately.展开更多
There is a great demand for in-situ real-time chemical sensors in the oceanographic research, to measure the chemical components under the deep sea. The ISE (Ion Selective Electrode) is commonly used as a detecting pa...There is a great demand for in-situ real-time chemical sensors in the oceanographic research, to measure the chemical components under the deep sea. The ISE (Ion Selective Electrode) is commonly used as a detecting part of deep-sea electro-chemical sensors. The paper highlights the solidification and micromation of the working and reference electrodes. The sensors of pH and H 2S with a thermal probe are accomplished after the solution of configuration of electrodes and signal processing. The sensor system has been tested successfully in the cruise of DY105-12, 14 sponsored by China Ocean Mineral Research and Exploitation Association(COMRA).展开更多
Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised...Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4–8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.展开更多
A strain of psychrophilic bacterium, 2-5-10-1, which produces low-temperature lipase, is isolated from the deep sea of Prydz Bay in Southern Ocean. The highest lipase secretion of this strain is observed at 5 degreesC...A strain of psychrophilic bacterium, 2-5-10-1, which produces low-temperature lipase, is isolated from the deep sea of Prydz Bay in Southern Ocean. The highest lipase secretion of this strain is observed at 5 degreesC and this temperature is also for optimal growth. Tween 80 and olive oil enhance secretion of lipase. The optimal temperature and pH for lipase activity are 35 degreesC and 7.5 degreesC respectively. At 0degreesC, the lipase still has 37% relative enzyme activity. The lipase shows high thermolability, more than 50% activity lost after incubation at 60 degreesC for 15 min. EDTA has no effect on lipase activity, indicating the lipase activity is independent of divalent cation. In contrast, the lipase activity is inhibited drastically by Cu2+ and Zn2+.展开更多
A flexible connector of lifting pipes in a deep sea mining system is designed. The buttress thread （ based on API standard） is used and foreign experience in connector design is referred to. With this kind of connec...A flexible connector of lifting pipes in a deep sea mining system is designed. The buttress thread （ based on API standard） is used and foreign experience in connector design is referred to. With this kind of connector, the lifting pipe wiU only bear the axial force, free of moment. The strength of the connector is analyzed in detail, including the connecting strength of the buttress thread, the dynamic load of the pipe system, pressures inside and outside of the pipe, the lateral stress of the pipe wall and so on. Especially, a geometric model is built for 3-D contact stress analysis. The distribution graph of contact stress is presented. It is indicated that the strength of the spherical connector meets the demand.展开更多
In order to study buckling propagation mechanism in deep sea pipelines, the contact between pipeline's inner walls in buckling process was studied. A two-dimensional ring model was used to represent the pipeline a...In order to study buckling propagation mechanism in deep sea pipelines, the contact between pipeline's inner walls in buckling process was studied. A two-dimensional ring model was used to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between inner walls. Based on the elastoplastic constitutive relationship and the principle of virtual work theory, the coupling effect of pipeline's nonlinear large deformation and wall contact was included in the theoretical analysis with the aid of MATLAB, and the application scope of the theoretical model was also discussed. The calculated results show that during the loading process, the change in external pressure is closely related to the distribution of section stress, and once the walls are contacting each other, the external pressure increases and then remains stable after it reaches a specific value. Without fracture, the pipeline section will stop showing deformation. The results of theoretical calculations agree well with those of numerical simulations. Finally, in order to ensure reliability and accuracy of the theoretical results, the collapse pressure and propagation pressure were both verified by numerical simulations and experiments. Therefore, the theoretical model can be used to analyze pipeline's buckling deformation and contact between pipeline's inner walls, which forms the basis for further research on three-dimensional buckling propagation.展开更多
Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles（AUVs）.To estimate the vehicle position,we present an algorithm using an extended Kalman filter（EKF） to integrate dead-reckon...Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles（AUVs）.To estimate the vehicle position,we present an algorithm using an extended Kalman filter（EKF） to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment.Owing to high latency,variable sound speed multipath transmissions and unreliability in acoustic measurements,outlier recognition techniques are proposed as well.The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments.Our results show the improved performance over prior techniques based on position computation.展开更多
In order to obtain novel secondary metabolites, a deep sea inhabiting fungus Aspergillus versicolor CXCTD-06-6a was investigated. One new diketopiperazine brevianamide W(1a), as well as five known diketopiperazine alk...In order to obtain novel secondary metabolites, a deep sea inhabiting fungus Aspergillus versicolor CXCTD-06-6a was investigated. One new diketopiperazine brevianamide W(1a), as well as five known diketopiperazine alkaloids, diketopiperazine V(1b), brevianamide Q(2), brevianamide R(3), brevianamide K(4), and brevianamide E(5), were isolated from the Et OAc extract of the fermentation broth. Their structures were elucidated by spectroscopy techniques(NMR, MS). The six compounds exhibited moderate radical scavenging activity against DPPH with clearance ratio of 55.0%(1a and 1b), 53.7%(2), 46.2%(3), 61.4%(4) and 19.3%(5) at a concentration of 13.9 μmol L-1, respectively; while the positive control ascorbic acid showed a ratio of 70.3% at the concentration of 28.4 μmol L-1.展开更多
This paper describes the implementation of a data logger for the real-time in-situ monitoring of hydrothermal systems. A compact mechanical structure ensures the security and reliability of data logger when used under...This paper describes the implementation of a data logger for the real-time in-situ monitoring of hydrothermal systems. A compact mechanical structure ensures the security and reliability of data logger when used under deep sea. The data logger is a battery powered instrument, which can connect chemical sensors （pH electrode, H2S electrode, H2 electrode） and temperature sensors. In order to achieve major energy savings, dynamic power management is implemented in hardware design and software design. The working current of the data logger in idle mode and active mode is 15 μA and 1.44 mA respectively, which greatly extends the working time of battery. The data logger has been successftdly tested in the first Sino-American Cooperative Deep Submergence Project from August 13 to September 3, 2005.展开更多
The experiment system of 1000 m deep sea mining system is built up with the similarity theory. Sine mechanism is used to simulate mining ship to generate lateral shock excitation by ocean wave. Simulation and experime...The experiment system of 1000 m deep sea mining system is built up with the similarity theory. Sine mechanism is used to simulate mining ship to generate lateral shock excitation by ocean wave. Simulation and experiment of spherical joint connecting deep sea mining system has been done in band six marine conditions. The results indicate that the moment of spherical joint connecting deep sea mining is smaller than that of the thread connected ones, the lifting pipe of sphelical joint is ＂flexible pipe＂. The flexural torque of the articulated lifting pipe system in pump and buffer is generally periodic variation with some irregularity, the value is stable on 60 N·S, and it is obviously smaller than that of the fixed lifting pipe system; The total displacement exhibits cyclic variation pattern, and the periodicity of them is longer than that of sea current. The results of experiment and simulation are basically consistent. And the analysis in the paper offers theoretical foundation of 1000 m deep sea mining system in China.展开更多
Depth-dependent distribution patterns of bacterial and archaeal communities in deep sea water column around the Ninetyeast Ridge in the Indian Ocean were investigated using 16S rRNA gene profiling.Sampling was conduct...Depth-dependent distribution patterns of bacterial and archaeal communities in deep sea water column around the Ninetyeast Ridge in the Indian Ocean were investigated using 16S rRNA gene profiling.Sampling was conducted at the northern Ninetyeast Ridge(1°59.89′N–9°59.70′S,87°58.90′E–88°00.03′E)from September to November 2016 where samples were collected from the bathyal(1000 m)to bathypelagic depths(>4000 m)in four different stations.A total of 1565405 clean data falling into 6712 bacterial OTUs and 1452727 clean data falling into 806 archaeal OTUs based on 97%similarity level were analyzed.Most of the bacterial 16S rRNA gene sequences were affiliated with Gammaproteobacteria,followed by Alphaproteobacteria and Bacteroidia.The archaeal 16S rRNA gene sequences mostly affiliated to Nitrososphaeria(Thaumarchaeota)dominated with relative abundances ranging from 52.68%to 97.2%,followed by Thermoplasmata(Euryarchaeota).Vertical partitioning of bacterial and archaeal communities among different water layers was observed.Canonical correspondence analysis(CCA)and Spearman’s correlations revealed that depth(P=0.003),dissolved oxygen(P=0.019),and nitrite(P=0.033)were the main environmental factors affecting bacterial community structure at genus level in the Ninetyeast Ridge.On the other hand,the first two CCA axes accounted for 74.4%of the explained total variance,it seems that the archaeal communities at genus level were heavily influenced by the environmental variables including depth,dissolved oxygen(DO),nitrite,salinity,phosphate,ammonia,nitrate,and silicate,but none of them exhibited any significant correlation on the structuring(P>0.1).展开更多
As a major aldehyde pollutant widely existing in industry and our daily life, acetaldehyde is more and more harmful to human health. As characteristic habitat niche, bacteria from deep sea environments are abundant an...As a major aldehyde pollutant widely existing in industry and our daily life, acetaldehyde is more and more harmful to human health. As characteristic habitat niche, bacteria from deep sea environments are abundant and distinctive in heredity, physiology and ecological functions. Thus, the development of acetaldehyde-degrading bacteria from deep sea provides a new method to harness acetaldehyde pollutant. Firstly, in this study,acetaldehyde-degrading bacteria in the deep sea water of the West Pacific Ocean were enriched in situ and in the laboratory respectively, and then the diversity of uncultured bacteria was studied by using 16 S r RNA genes. Then acetaldehyde-degrading strains were isolated from two samples, including enrichment in situ and enrichment in laboratory samples of deep sea water from the West Pacific Ocean using acetaldehyde as the sole carbon source,and then the ability of acetaldehyde degradation was detected. Our results showed that the main uncultured bacteria of two samples with different enrichment approaches were similar, including Proteobacteria,Actinobacteria, Firmicutes, Cyanobacteria, but the structure of bacterial community were significant different.Four subgroups, α, γ, δ and ε, were found in Proteobacteria group. The γ-Proteobacteria was dominant（63.5%clones in laboratory enriched sample, 75% clones in situ enriched sample）. The species belonged to γ-Proteobacteria and their proportion was nearly identical between the two enrichment samples, and Vibrio was the predominant genus（45% in laboratory enriched sample, 48.5% in situ enriched sample）, followed by Halomonas（9% in situ enriched sample） and Streptococcus（6% in laboratory enriched sample）. A total of 12 acetaldehyde-degrading strains were isolated from the two samples, which belonged to Vibrio, Halomonas,Pseudoalteromonas, Pseudomonas and Bacillus of γ-Proteobacteria. Strains ACH-L-5, ACH-L-8 and ACH-S-12,belonging to Vibrio and Halomonas, have strong ability of acetaldehyde degradation, which could tolerate 1.5 g/L acetaldehyde and degrade 350 mg/L acetaldehyde within 24 hours. Our results indicated that bacteria of γ-Proteobacteria may play an important role in carbon cycle of deep sea environments, especial the bacteria belonging to Vibrio and Halomonas and these strains was suggested for their potentials in government of aldehyde pollutants.展开更多
The present status of deep sea bed mining technology for polymetallic nodules has been critically examined in light of its history of development the UNCLoS (the United Nation Convention on the Law of the Sea) regime ...The present status of deep sea bed mining technology for polymetallic nodules has been critically examined in light of its history of development the UNCLoS (the United Nation Convention on the Law of the Sea) regime and the current trends in research.The critical technologies have been highlighted and the need for system integration underscored. The deep sea bed environment and the engineering challenge were presented and the necessary features of the deep sea bed mining system for commercial mining was analyzed. The key accomplishments, problems and future bends in research in the development of the mining system are also discussed. Finally, it points out that the technology gaps can be filled by the bine commercial mining is undertaken as a result of market conditions in its favor.展开更多
The fields of structural geology and tectonics have witnessed great progress over the last decade and are poised for further expansion in the future. One of the significant breakthroughs is the establishment of the &#...The fields of structural geology and tectonics have witnessed great progress over the last decade and are poised for further expansion in the future. One of the significant breakthroughs is the establishment of the 'Beyond Plate Tectonics Theory' where a combination of conceptual models and numerical modeling on plume tectonics and plate tectonics has enabled new insights into the structural and tectonic architecture and processes in the deep interior and deep sea. This paper synthesizes developments of structural geology and tectonics from a macroscopic perspective in deep interior and deep sea. Four key techniques are also reviewed: satellite altimetry for surface structures in deep-sea multi-beam sea-floor mapping; tomography for tectonics of the deep interior; diverse modeling approaches and software for unfolding dynamic evolution; and techniques for HT/HP experiments on material rheology and in situ component measurements.展开更多
Corrosion in complex coupling environments is an important issue in corrosion field, because it is difficult to take into account a large number of environment factors and their interactions. Design of Experiment(DOE)...Corrosion in complex coupling environments is an important issue in corrosion field, because it is difficult to take into account a large number of environment factors and their interactions. Design of Experiment(DOE) can present a methodology to deal with this difficulty, although DOE is not commonly spread in corrosion field. Thus, modeling corrosion of Ni-Cr-Mo-V steel in deep sea environment was performed in order to provide example demonstrating the advantage of DOE. In addition, an artificial neural network mapping using back-propagation method was developed for Ni-Cr-Mo-V steel such that the ANN model can be used to predict polarization curves under different complex sea environments without experimentation. Furthermore, roles of environment factors on corrosion of Ni-Cr-Mo-V steel in deep sea environment were discussed.展开更多
The corrosion behaviors of X65 steel in the artificial seawater at different hydrostatic pressures are investigated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy measurements and...The corrosion behaviors of X65 steel in the artificial seawater at different hydrostatic pressures are investigated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy measurements and weight loss measurements.The corroded morphologies and the corrosion products are also investigated by scanning electron microscopy, X-ray diffraction analysis and Raman analysis.The results show that the corrosion current increases as the hydrostatic pressure increases.The charge transfer resistance decreases as the hydrostatic pressure increases.The corrosion products are mainly composed of γ-FeOOH and Fe3O4 at the atmospheric pressure, while the main components are γ-FeOOH, Fe3O4, and γ-Fe2O3 at the high pressure.The hydrostatic pressure accelerates the corrosion of X65 steel due to its effect on the chemical and physical properties of corrosion products, including the promoted reduction of γ-FeOOH and the wider and deeper cracks on the corrosion products layer.展开更多
In order to improve the navigation accuracy of human occupied vehicle(HOV)precisely and efficiently,an innovative hybrid approach based on unscented Kalman filter(UKF)and support vector machine(SVM)is proposed to fuse...In order to improve the navigation accuracy of human occupied vehicle(HOV)precisely and efficiently,an innovative hybrid approach based on unscented Kalman filter(UKF)and support vector machine(SVM)is proposed to fuse integrated navigation data.HOV is generally equipped with long baseline(LBL)acoustic positioning system and dead reckoning(DR)as an integrated navigation system.UKF is adopted to estimate the state of the dynamic model because of its good performance in filtering nonlinear problems.An accurate and stable filtering result can be obtained when both LBL and DR are online.At the same time,SVM is utilized to train DR information with the result when LBL outrages,and the particle swarm optimization(PSO)algorithm is employed for SVM parameters optimization.Therefore,the integrated navigation system can maintain a good performance when the LBL is off-line.Simulation results with the real navigation data of Jiaolong HOV show that the methodology proposed here is able to meet the needs of HOV application.展开更多
基金the National Key R&D Program of China(No.2022YFB3808800)the National Natural Science Foundation of China(Nos.52301406 and 52375219)+2 种基金the Natural Science Foundation of Zhejiang Province(No.LR21E050001)the China Postdoctoral Science Foundation(No.2023M733600)the Ningbo Natural Science Foundation(No.2023J329).
文摘Deep sea,with rich oil,gas,and mineral resources,plays an increasingly crucial role in scientific and industrial realms.However,the highly corrosive feature of deep sea hinders further exploration and development,which requires metal materials with robust corrosion resistance.This review covers an in-depth and all-around overview of the up-to-date advances in corrosion and protection of metals in deep-sea environment.Firstly,the unique characteristics of deep-sea environment are summarized in detail.Subsequently,the corrosion performances of metals in both in situ and simulated deep-sea environments are illustrated systematically.Furthermore,corrosion prevent strategies of metals,including sacrificial anode protection,organic coatings,as well as coatings achieved by physical vapor deposition(PVD coatings),are highlighted.Finally,we outline current challenges and development trends of corrosion and protection of metals in deep-sea environment in the future.The purpose of this review is not only to summarize the recent progress on metal corrosion and protection in deep sea,but also to aid us in understanding them more comprehensively and deeply in a short time,so as to boost their fast development.
基金financially supported by Shenzhen Science and Technology Program(Nos.JSGG20220831105002005 and KJZD20231025152759002)the National Natural Science Foundation of China(Nos.52274133 and 523B2101).
文摘Natural gas hydrate(NGH)has a bright future as a clean energy source with huge reserves.Coring is one of the most direct methods for NGH exploration and research.Preserving the in-situ properties of the core as much as possible during the coring process is crucial for the assessment of NGH resources.However,most existing NGH coring techniques cannot preserve the in-situ temperature of NGH,leading to distortion of the physical properties of the obtained core,which makes it difficult to effectively guide NGH exploration and development.To overcome this limitation,this study introduces an innovative active temperature-preserved coring method for NGH utilizing phase change materials(PCM).An active temperature-preserved corer(ATPC)is designed and developed,and an indoor experimental system is established to investigate the heat transfer during the coring process.Based on the experimental results under different environment temperatures,a heat transfer model for the entire ATPC coring process has been established.The indoor experimental results are consistent with the theoretical predictions of the heat transfer model,confirming its validity.This model has reconstructed the temperature changes of the NGH core during the coring process,demonstrating that compared to the traditional coring method with only passive temperature-preserved measures,ATPC can effectively reduce the core temperature by more than 5.25℃.With ATPC,at environment temperatures of 15,20,25,and 30℃,the duration of low-temperature state for the NGH core is 53.85,32.87,20.32,and 11.83 min,respectively.These findings provide new perspectives on temperature-preserving core sampling in NGH and provide technical support for exploration and development in NGH.
基金supported by the National Key R&D Program of China (No.2021YFC2801202)the National Natural Science Foundation of China (No.42076224)the Fundamental Research Funds for the Central Universities (No.202262012)。
文摘The chirp sub-bottom profiler,for its high resolution,easy accessibility and cost-effectiveness,has been widely used in acoustic detection.In this paper,the acoustic impedance and grain size compositions were obtained based on the chirp sub-bottom profiler data collected in the Chukchi Plateau area during the 11th Arctic Expedition of China.The time-domain adaptive search matching algorithm was used and validated on our established theoretical model.The misfit between the inversion result and the theoretical model is less than 0.067%.The grain size was calculated according to the empirical relationship between the acoustic impedance and the grain size of the sediment.The average acoustic impedance of sub-seafloor strata is 2.5026×10^(6) kg(s m^(2))^(-1)and the average grain size(θvalue)of the seafloor surface sediment is 7.1498,indicating the predominant occurrence of very fine silt sediment in the study area.Comparison of the inversion results and the laboratory measurements of nearby borehole samples shows that they are in general agreement.
基金Supported by the NSFC (under Grant Nos.5070900 and 10772040)the National High Tech Research and Development Program of China (2006AA09A109-3)
文摘Based on the fifth-order Stokes regular wave theory, a simplified model for extreme-wave kinematics in deep sea was developed. In this model, from the wave records the average of two neighboring wave periods for the extreme crest or trough was defined as the period of the Stokes wave by the up and down zero-crossing methods. Then the input wave amplitude was deduced by substituting the wave period and extreme crest or trough into the expression for the fifth-order Stokes wave elevation. Thus the corresponding formula for the wave velocity can be used to describe kinematics beneath the extreme wave. By comparison with the published numerical models and experimental data, the proposed model is validated to be able to calculate the extreme wave velocity rather easily and accurately.
基金The research program was financially supported by the Joint Program of Chinese 863 Project (Grant No. 2001AA612020 4) and the sea trial support from COMRA, China Ocean Mineral Research and Exploitation Association as well.
文摘There is a great demand for in-situ real-time chemical sensors in the oceanographic research, to measure the chemical components under the deep sea. The ISE (Ion Selective Electrode) is commonly used as a detecting part of deep-sea electro-chemical sensors. The paper highlights the solidification and micromation of the working and reference electrodes. The sensors of pH and H 2S with a thermal probe are accomplished after the solution of configuration of electrodes and signal processing. The sensor system has been tested successfully in the cruise of DY105-12, 14 sponsored by China Ocean Mineral Research and Exploitation Association(COMRA).
基金Supported by the National High Technology Research and Development Program of China (863 Program, 2006AA09Z349)the National Basic Research Program of China (2007CB411703)
文摘Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4–8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.
文摘A strain of psychrophilic bacterium, 2-5-10-1, which produces low-temperature lipase, is isolated from the deep sea of Prydz Bay in Southern Ocean. The highest lipase secretion of this strain is observed at 5 degreesC and this temperature is also for optimal growth. Tween 80 and olive oil enhance secretion of lipase. The optimal temperature and pH for lipase activity are 35 degreesC and 7.5 degreesC respectively. At 0degreesC, the lipase still has 37% relative enzyme activity. The lipase shows high thermolability, more than 50% activity lost after incubation at 60 degreesC for 15 min. EDTA has no effect on lipase activity, indicating the lipase activity is independent of divalent cation. In contrast, the lipase activity is inhibited drastically by Cu2+ and Zn2+.
基金This research was financially supported by China Ocean Mineral Resources R &D Association (Grant No. DY105-03-02-17) .
文摘A flexible connector of lifting pipes in a deep sea mining system is designed. The buttress thread （ based on API standard） is used and foreign experience in connector design is referred to. With this kind of connector, the lifting pipe wiU only bear the axial force, free of moment. The strength of the connector is analyzed in detail, including the connecting strength of the buttress thread, the dynamic load of the pipe system, pressures inside and outside of the pipe, the lateral stress of the pipe wall and so on. Especially, a geometric model is built for 3-D contact stress analysis. The distribution graph of contact stress is presented. It is indicated that the strength of the spherical connector meets the demand.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51239008 and 51179126)the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2011ZX05026-005)
文摘In order to study buckling propagation mechanism in deep sea pipelines, the contact between pipeline's inner walls in buckling process was studied. A two-dimensional ring model was used to represent the pipeline and a nonlinear spring model was adopted to simulate the contact between inner walls. Based on the elastoplastic constitutive relationship and the principle of virtual work theory, the coupling effect of pipeline's nonlinear large deformation and wall contact was included in the theoretical analysis with the aid of MATLAB, and the application scope of the theoretical model was also discussed. The calculated results show that during the loading process, the change in external pressure is closely related to the distribution of section stress, and once the walls are contacting each other, the external pressure increases and then remains stable after it reaches a specific value. Without fracture, the pipeline section will stop showing deformation. The results of theoretical calculations agree well with those of numerical simulations. Finally, in order to ensure reliability and accuracy of the theoretical results, the collapse pressure and propagation pressure were both verified by numerical simulations and experiments. Therefore, the theoretical model can be used to analyze pipeline's buckling deformation and contact between pipeline's inner walls, which forms the basis for further research on three-dimensional buckling propagation.
基金financially supported by the National Natural Science Foundation of China(Grant No.51309215)
文摘Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles（AUVs）.To estimate the vehicle position,we present an algorithm using an extended Kalman filter（EKF） to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment.Owing to high latency,variable sound speed multipath transmissions and unreliability in acoustic measurements,outlier recognition techniques are proposed as well.The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments.Our results show the improved performance over prior techniques based on position computation.
基金supported by Chinese National Science Fund (No. 41176120)Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province (No. BS2010HZ027)+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education (No. 20100132120026)the Fifty First Postdoctoral Fund of China (2012M511552)
文摘In order to obtain novel secondary metabolites, a deep sea inhabiting fungus Aspergillus versicolor CXCTD-06-6a was investigated. One new diketopiperazine brevianamide W(1a), as well as five known diketopiperazine alkaloids, diketopiperazine V(1b), brevianamide Q(2), brevianamide R(3), brevianamide K(4), and brevianamide E(5), were isolated from the Et OAc extract of the fermentation broth. Their structures were elucidated by spectroscopy techniques(NMR, MS). The six compounds exhibited moderate radical scavenging activity against DPPH with clearance ratio of 55.0%(1a and 1b), 53.7%(2), 46.2%(3), 61.4%(4) and 19.3%(5) at a concentration of 13.9 μmol L-1, respectively; while the positive control ascorbic acid showed a ratio of 70.3% at the concentration of 28.4 μmol L-1.
基金supported by the International Cooperative Key Project(Grant No.2004DFA04900)Ministry of Sciences and Technology of PRC,and the National Natural Science Foundation of China (Grant Nos.40637037 and 50675198)
文摘This paper describes the implementation of a data logger for the real-time in-situ monitoring of hydrothermal systems. A compact mechanical structure ensures the security and reliability of data logger when used under deep sea. The data logger is a battery powered instrument, which can connect chemical sensors （pH electrode, H2S electrode, H2 electrode） and temperature sensors. In order to achieve major energy savings, dynamic power management is implemented in hardware design and software design. The working current of the data logger in idle mode and active mode is 15 μA and 1.44 mA respectively, which greatly extends the working time of battery. The data logger has been successftdly tested in the first Sino-American Cooperative Deep Submergence Project from August 13 to September 3, 2005.
基金This research was financially supported by China Ocean Mineral Resources Reasearch and Design Association (GrantNo DY105-03-02-17)Ph.D Programs Foundation of Ministry of Education of China (Grant No20060008025)
文摘The experiment system of 1000 m deep sea mining system is built up with the similarity theory. Sine mechanism is used to simulate mining ship to generate lateral shock excitation by ocean wave. Simulation and experiment of spherical joint connecting deep sea mining system has been done in band six marine conditions. The results indicate that the moment of spherical joint connecting deep sea mining is smaller than that of the thread connected ones, the lifting pipe of sphelical joint is ＂flexible pipe＂. The flexural torque of the articulated lifting pipe system in pump and buffer is generally periodic variation with some irregularity, the value is stable on 60 N·S, and it is obviously smaller than that of the fixed lifting pipe system; The total displacement exhibits cyclic variation pattern, and the periodicity of them is longer than that of sea current. The results of experiment and simulation are basically consistent. And the analysis in the paper offers theoretical foundation of 1000 m deep sea mining system in China.
基金Supported by the China Ocean Mineral Resources Research and Development Association Program(Nos.DY135-E2-1-01,DY135-E2-4-00)the China Global Sea-Atmosphere Interaction Research Program(No.GASI-02-IND-STSsum)the S&T Innovation Project of Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ14)。
文摘Depth-dependent distribution patterns of bacterial and archaeal communities in deep sea water column around the Ninetyeast Ridge in the Indian Ocean were investigated using 16S rRNA gene profiling.Sampling was conducted at the northern Ninetyeast Ridge(1°59.89′N–9°59.70′S,87°58.90′E–88°00.03′E)from September to November 2016 where samples were collected from the bathyal(1000 m)to bathypelagic depths(>4000 m)in four different stations.A total of 1565405 clean data falling into 6712 bacterial OTUs and 1452727 clean data falling into 806 archaeal OTUs based on 97%similarity level were analyzed.Most of the bacterial 16S rRNA gene sequences were affiliated with Gammaproteobacteria,followed by Alphaproteobacteria and Bacteroidia.The archaeal 16S rRNA gene sequences mostly affiliated to Nitrososphaeria(Thaumarchaeota)dominated with relative abundances ranging from 52.68%to 97.2%,followed by Thermoplasmata(Euryarchaeota).Vertical partitioning of bacterial and archaeal communities among different water layers was observed.Canonical correspondence analysis(CCA)and Spearman’s correlations revealed that depth(P=0.003),dissolved oxygen(P=0.019),and nitrite(P=0.033)were the main environmental factors affecting bacterial community structure at genus level in the Ninetyeast Ridge.On the other hand,the first two CCA axes accounted for 74.4%of the explained total variance,it seems that the archaeal communities at genus level were heavily influenced by the environmental variables including depth,dissolved oxygen(DO),nitrite,salinity,phosphate,ammonia,nitrate,and silicate,but none of them exhibited any significant correlation on the structuring(P>0.1).
基金The Xiamen Ocean Economic Innovation and Development Demonstration Project under contract No.16PZP001SF16
文摘As a major aldehyde pollutant widely existing in industry and our daily life, acetaldehyde is more and more harmful to human health. As characteristic habitat niche, bacteria from deep sea environments are abundant and distinctive in heredity, physiology and ecological functions. Thus, the development of acetaldehyde-degrading bacteria from deep sea provides a new method to harness acetaldehyde pollutant. Firstly, in this study,acetaldehyde-degrading bacteria in the deep sea water of the West Pacific Ocean were enriched in situ and in the laboratory respectively, and then the diversity of uncultured bacteria was studied by using 16 S r RNA genes. Then acetaldehyde-degrading strains were isolated from two samples, including enrichment in situ and enrichment in laboratory samples of deep sea water from the West Pacific Ocean using acetaldehyde as the sole carbon source,and then the ability of acetaldehyde degradation was detected. Our results showed that the main uncultured bacteria of two samples with different enrichment approaches were similar, including Proteobacteria,Actinobacteria, Firmicutes, Cyanobacteria, but the structure of bacterial community were significant different.Four subgroups, α, γ, δ and ε, were found in Proteobacteria group. The γ-Proteobacteria was dominant（63.5%clones in laboratory enriched sample, 75% clones in situ enriched sample）. The species belonged to γ-Proteobacteria and their proportion was nearly identical between the two enrichment samples, and Vibrio was the predominant genus（45% in laboratory enriched sample, 48.5% in situ enriched sample）, followed by Halomonas（9% in situ enriched sample） and Streptococcus（6% in laboratory enriched sample）. A total of 12 acetaldehyde-degrading strains were isolated from the two samples, which belonged to Vibrio, Halomonas,Pseudoalteromonas, Pseudomonas and Bacillus of γ-Proteobacteria. Strains ACH-L-5, ACH-L-8 and ACH-S-12,belonging to Vibrio and Halomonas, have strong ability of acetaldehyde degradation, which could tolerate 1.5 g/L acetaldehyde and degrade 350 mg/L acetaldehyde within 24 hours. Our results indicated that bacteria of γ-Proteobacteria may play an important role in carbon cycle of deep sea environments, especial the bacteria belonging to Vibrio and Halomonas and these strains was suggested for their potentials in government of aldehyde pollutants.
文摘The present status of deep sea bed mining technology for polymetallic nodules has been critically examined in light of its history of development the UNCLoS (the United Nation Convention on the Law of the Sea) regime and the current trends in research.The critical technologies have been highlighted and the need for system integration underscored. The deep sea bed environment and the engineering challenge were presented and the necessary features of the deep sea bed mining system for commercial mining was analyzed. The key accomplishments, problems and future bends in research in the development of the mining system are also discussed. Finally, it points out that the technology gaps can be filled by the bine commercial mining is undertaken as a result of market conditions in its favor.
基金Funding Sources:Marine 863 Project (No.2009AA093401)Projects of the National Natural Science Foundation of China (Nos.41072152,90814011 and 41190072)
文摘The fields of structural geology and tectonics have witnessed great progress over the last decade and are poised for further expansion in the future. One of the significant breakthroughs is the establishment of the 'Beyond Plate Tectonics Theory' where a combination of conceptual models and numerical modeling on plume tectonics and plate tectonics has enabled new insights into the structural and tectonic architecture and processes in the deep interior and deep sea. This paper synthesizes developments of structural geology and tectonics from a macroscopic perspective in deep interior and deep sea. Four key techniques are also reviewed: satellite altimetry for surface structures in deep-sea multi-beam sea-floor mapping; tomography for tectonics of the deep interior; diverse modeling approaches and software for unfolding dynamic evolution; and techniques for HT/HP experiments on material rheology and in situ component measurements.
基金the financial support of the National Natural Science Foundation of China(No.51371182)the National Program for the Young Top-notch Professionals and the Fundamental Research Funds for the Central Universities(N170205002)
文摘Corrosion in complex coupling environments is an important issue in corrosion field, because it is difficult to take into account a large number of environment factors and their interactions. Design of Experiment(DOE) can present a methodology to deal with this difficulty, although DOE is not commonly spread in corrosion field. Thus, modeling corrosion of Ni-Cr-Mo-V steel in deep sea environment was performed in order to provide example demonstrating the advantage of DOE. In addition, an artificial neural network mapping using back-propagation method was developed for Ni-Cr-Mo-V steel such that the ANN model can be used to predict polarization curves under different complex sea environments without experimentation. Furthermore, roles of environment factors on corrosion of Ni-Cr-Mo-V steel in deep sea environment were discussed.
基金supported by National Basic Research Program of China (2014CB046801)National Natural Science Foundation of China (51471117)Key Project of Tianjin Natural Science Foundation (13JCZDJC29500)
文摘The corrosion behaviors of X65 steel in the artificial seawater at different hydrostatic pressures are investigated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy measurements and weight loss measurements.The corroded morphologies and the corrosion products are also investigated by scanning electron microscopy, X-ray diffraction analysis and Raman analysis.The results show that the corrosion current increases as the hydrostatic pressure increases.The charge transfer resistance decreases as the hydrostatic pressure increases.The corrosion products are mainly composed of γ-FeOOH and Fe3O4 at the atmospheric pressure, while the main components are γ-FeOOH, Fe3O4, and γ-Fe2O3 at the high pressure.The hydrostatic pressure accelerates the corrosion of X65 steel due to its effect on the chemical and physical properties of corrosion products, including the promoted reduction of γ-FeOOH and the wider and deeper cracks on the corrosion products layer.
基金National High Technology Development Program of China(2009AA093302,2014AA09A110)the Chinese Academy of Strategic Leading Science and Technology Special(XDA11040104)
文摘In order to improve the navigation accuracy of human occupied vehicle(HOV)precisely and efficiently,an innovative hybrid approach based on unscented Kalman filter(UKF)and support vector machine(SVM)is proposed to fuse integrated navigation data.HOV is generally equipped with long baseline(LBL)acoustic positioning system and dead reckoning(DR)as an integrated navigation system.UKF is adopted to estimate the state of the dynamic model because of its good performance in filtering nonlinear problems.An accurate and stable filtering result can be obtained when both LBL and DR are online.At the same time,SVM is utilized to train DR information with the result when LBL outrages,and the particle swarm optimization(PSO)algorithm is employed for SVM parameters optimization.Therefore,the integrated navigation system can maintain a good performance when the LBL is off-line.Simulation results with the real navigation data of Jiaolong HOV show that the methodology proposed here is able to meet the needs of HOV application.
