- LUO Feng;WANG Yi;TAO Aifeng;SHI Jian;WANG Yongzhi;ZHANG Chi;
Climate change affects the activity of global and regional tropical cyclones(TCs).Among all TCs,typical super typhoons(STYs) are particularly devastating because they maintain their intensity when landing on the coast and thus cause casualties,economic losses,and environmental damage.Using a 3D tidal model,we reconstructed the typhoon(TY) wind field to simulate the storm surge induced by typical STYs.The TY activity was then analyzed using historical data.Results showed a downtrend of varying degrees in the annual frequency of STYs and TCs in the Western North Pacific(WNP) Basin,with a significant trend change observed for TCs from 1949 to 2021.A large difference in the interannual change in frequency was found between STYs and TCs in the WNP and Eastern China Sea(ECS).Along the coast of EC,the frequency of landfall TCs showed a weak downtrend,and the typical STYs showed reverse micro growth with peak activity in August.Zhejiang,Fujian,and Taiwan were highly vulnerable to the frontal hits of typical STYs.Affected by climate change,the average lifetime maximum intensity(LMI) locations and landfall locations of typical STYs in the ECS basin showed a significant poleward migration trend.In addition,the annual average LMI and accumulated cyclone energy showed an uptrend,indicating the increasing severity of the disaster risk.Affected by the typical STY activity in the ECS,the maximum storm surge area also showed poleward migration,and the coast of North China faced potential growth in high storm surge risks.
2024年02期 v.23 277-286页 [查看摘要][在线阅读][下载 3287K] - HU Yuyi;SHAO Weizeng;SHEN Wei;ZUO Juncheng;JIANG Tao;HU Song;
The aim of this study is to investigate the sea surface temperature(SST) cooling as typhoons pass the Kuroshio Current.A numerical circulation model,denoted as the Stony Brook Parallel Ocean Model(sbPOM),was used to simulate the SST,which includes four wave-induced effect terms(i.e.,radiation stress,nonbreaking waves,Stokes drift,and breaking waves) simulated using the third-generation wave model,called WAVEWATCH-Ⅲ(WW3).The significant wave height(SWH) measurements from the Jason-2 altimeter were used to validate the WW3-simulated results,yielding a root mean square error(RMSE) of less than 0.50 m and a correlation coefficient(COR) of approximately 0.93.The water temperature measured from the Advanced Research and Global Observation Satellite was applied to validate the model simulation.Accordingly,the RMSE of the SST is 0.92℃ with a COR of approximately 0.99.As revealed in the sbPOM-simulated SST fields,a reduction in the SST at the Kuroshio Current region was observed as a typhoon passed,although the water temperature of the Kuroshio Current is relatively high.The variation of the SST is consistent with that of the current,whereas the maximum SST lagged behind the occurrence of the peak SWH.Moreover,the Stokes drift plays an important role in the SST cooling after analyzing four wave-induced terms in the background of the Kuroshio Current.The sensitivity experiment also showed that the accuracy of the water temperature was significantly reduced when including breaking waves,which play a negative role in the inside part of the ocean.The variation in the mean mixing layer depth(MLD) showed that a typhoon could enhance the mean MLD in the Kuroshio Current area in September and October,whereas a typhoon has little influence on the mean MLD in the Kuroshio Current area in May.Moreover,the mean MLD rapidly decreased with the weakening of the strong wind force and wave-induced effects when a typhoon crossed the Kuroshio Current.
2024年02期 v.23 287-303页 [查看摘要][在线阅读][下载 7570K] - WANG Yongjun;LI Tao;
In 2018 and 2021,the Drift-Towing Ocean Profilers(DTOP) provided extensive temperature and salinity data on the upper 120 m ocean through their drifts over the Alpha Ridge north of the Canada Basin.The thickness and temperature maximum of Alaska Coastal Water(ACW) ranged from 20 m to 40 m and-1.5℃ to -0.8℃,respectively,and the salinity generally maintained from 30.2 to 32.5.Comparison with World Ocean Atlas 2018's climatology manifested a 40 m-thick and warm ACW roughly exceeding the temperature maximum by 0.4–0.5℃ in June – August 2021.This anomalously warm ACW was highly related to the expansion of the Beaufort Gyre in the negative Arctic Oscillation phase.During summer,the under-ice oceanic heat flux F_w~(OHF) was elevated,with a maximum value of above 25 Wm~(-2).F_w~(OHF) was typically low in the freezing season,with an average value of 1.2 Wm~(-2).The estimates of upward heat flux contributed by ACW to the sea ice bottom F_w~(OHF) were in the range of 3–4 Wm~(-2) in June – August 2021,when ACW contained a heat content of more than 80 MJ m~(-2).The heat loss over this period was driven by a weak stratification upon the ACW layer associated with a surface mixed layer(SML) approaching the ACW core.After autumn,F_w~(OHF) was reduced(< 2 Wm~(-2)) except during rare events when it elevated F_w~(OHF) slightly.In addition,the intensive and widespread Ekman suction,which created a violent upwelling north of the Canada Basin,was largely responsible for the substantial cooling and thinning of the ACW layer in the summer of 2021.
2024年02期 v.23 304-316页 [查看摘要][在线阅读][下载 5059K] - HUANG Junlin;LI Jiao;LI Yan;GONG Pihai;GUAN Changtao;XIA Xu;
On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.
2024年02期 v.23 317-327页 [查看摘要][在线阅读][下载 4702K] - WANG Wei;WEI Weicheng;CHAI Bo;XIA Hao;WANG Yang;DU Juan;LIU Jizhixian;
Landslide-generated impulsive waves(LGWs) in reservoir areas can seriously threaten waterway safety as well as human life and properties around the two side slopes.The risk reduction and mitigation of such a hazard require the accurate prediction of near-field wave characteristics,such as wave amplitude and run-up.However,near-field LGW involves complicated fluid-solid interactions.Furthermore,the wave characteristics are closely related to various aspects,including the geometry and physical features of the slide,river,and body of water.However,the empirical or analytical methods used for rough estimation cannot derive accurate results,especially for deformable landslides,due to their significant geometry changes during the sliding process.In this study,the near-field waves generated by deformable landslides were simulated by smoothed particle hydrodynamics(SPH) based on multiphase flow.The deformable landslides were generalized as a kind of viscous flow by adopting the Herschel-Bulkley-Papanastasiou(HBP)-based nonNewtonian rheology model.The HBP model is capable of producing deformable landslide dynamics even though the high-speed sliding process is involved.In this study,an idealized experiment case originating from Lituya LGW and a practical case of Gongjiafang LGW were reproduced for verification and demonstration.The simulation results of both cases show satisfactory consistency with the experiment/investigation data in terms of landslide movement and near-field impulsive wave characteristics,thus indicating the applicability and accuracy of the proposed method.Finally,the effects of the HBP model's rheological parameters on the landslide dynamics and near-field wave characteristics are discussed,providing a parameter calibration method along with suggestions for further applications.
2024年02期 v.23 328-344页 [查看摘要][在线阅读][下载 4170K] - DING Hongyan;QIN Licheng;ZHANG Puyang;SONG Zhengrong;XIE Weiwei;
In this paper,the multi-body coupled dynamic characteristics of a semisubmersible platform and an HYSY 229 barge were investigated.First,coupled hydrodynamic analysis of the HYSY 229 barge and the semisubmersible platform was performed.Relevant hydrodynamic parameters were obtained using the retardation function method of three-dimensional frequency-domain potential flow theory.The results of the hydrodynamic analysis were highly consistent with the test findings,verifying the accuracy of the multifloating hydrodynamic coupling analysis,and key hydrodynamic parameters were solved for different water depths and the coupling effect.According to the obtained results,the hydrodynamic influence was the largest in shallow waters when the coupling effect was considered.Furthermore,the coupled motion equation combined with viscous damping,fender system,and mooring system was established,and the hydrodynamics,floating body motion,and dynamic response of the fender system were analyzed.Motion analysis revealed good agreement among the surge,sway,and yaw motions of the two floating bodies.However,when the wave period reached 10 s,the motion of the two floating bodies showed severe shock,and a relative motion was also observed.Therefore,excessive constraints should be added between the two floating bodies during construction to ensure construction safety.The numerical analysis and model test results of the semisubmersible platform and HYSY 229 barge at a water depth of 42 m and sea conditions of 0°,45°,and 90° were in good agreement,and the error was less than 5%.The maximum movement of the HYSY 229 barge reached 2.61 m in the sway direction,whereas that of the semisubmersible platform was 2.11 m.During construction,excessive constraints should be added between the two floating bodies to limit their relative movement and ensure construction safety.
2024年02期 v.23 345-357页 [查看摘要][在线阅读][下载 4868K] - GAO Shan;ZHANG Lixian;SHI Wei;WANG Wenhua;WANG Bin;LI Xin;
Recently,semisubmersible floating offshore wind turbine technologies have received considerable attention.For the coupled simulation of semisubmersible floating offshore wind energy,the platform is usually considered a rigid model,which could affect the calculation accuracy of the dynamic responses.The dynamic responses of a TripleSpar floating offshore wind turbine equipped with a 10 MW offshore wind turbine are discussed herein.The simulation of a floating offshore wind turbine under regular waves,white noise waves,and combined wind-wave conditions is conducted.The effects of the tower and platform flexibility on the motion and force responses of the TripleSpar semisubmersible floating offshore wind turbine are investigated.The results show that the flexibility of the tower and platform can influence the dynamic responses of a TripleSpar semisubmersible floating offshore wind turbine.Considering the flexibility of the tower and platform,the tower and platform pitch motions markedly increased compared with the fully rigid model.Moreover,the force responses,particularly for tower base loads,are considerably influenced by the flexibility of the tower and platform.Thus,the flexibility of the tower and platform for the coupled simulation of floating offshore wind turbines must be appropriately examined.
2024年02期 v.23 358-370页 [查看摘要][在线阅读][下载 2984K] - LIU Tao;GUO Zhenqi;ZHANG Yan;WU Chen;LIU Lele;DENG Shenggui;
The morphological changes in isolated bubbles in gassy silt play a critical role in the microscopic structures between soil particles and bubbles and macroscopic physical properties.Based on X-ray CT scanning experiments under various vertical loads(four levels),self-designed acoustic macro experiments,and a series of formula revisions to the macro-air-bearing silt sound-velocity prediction model,this paper discusses the macro-and micro-scale features of gassy silts from the Yellow River Delta.The samples consisted of different proportions of silt from the Yellow River Delta and porous media,and they were used to form two types of aerosol silts with initial gas contents of 4.23% and 7.67%.The results show that the air bubble content and external load considerably affect the microstructural parameters and acoustic behavior of gassy silt in the Yellow River Delta.The macroscopic sound velocity showed a linear positive correlation with vertical load and relation to microstructural parameters in varying manners and degrees.Based on the traditional Biot-Stoll acoustic model,the gas-phase medium coefficient was introduced for the proper calculation and prediction of the sound velocity of air-bearing silt.The errors of the overall prediction varied between 5.6% and 9.6%.
2024年02期 v.23 371-382页 [查看摘要][在线阅读][下载 3223K] - TIAN Yuan;GAO Fei;CAO Ke;LV Shenghua;DUAN Xiaoyong;YIN Ping;
Small mountainous rivers are characterized by large instantaneous fluxes and susceptible to extreme weather events,which can rapidly transport materials into the sea and have a significant impact on the ecological environment of estuaries and bays.In order to investigate the seasonal characteristics of nutrients in small mountainous rivers in the subtropical monsoon region and the output pattern to the sea during heavy precipitation,surveys on the mountainous rivers were carried out in Baixi watershed in August 2020(wet season),March 2021(dry season) and June 2021(Meiyu period).The results showed that the dissolved inorganic nitrogen(DIN)of the rivers has an average concentration of 752 μg L~(-1) in the wet season and 1472 μg L~(-1) in the dry season.The concentrations of dissolved inorganic phosphorus(DIP) in wet season and dry season were 63 μg L~(-1) and 51 μg L~(-1),respectively.Influenced by the changes of land use in sub-watersheds,DIN concentrations in the mainstream increased from 701 μg L~(-1) in the upper reaches to 1284 μg L~(-1) in the middle reaches.Two rainstorms during the Meiyu period in the watershed caused the pulse runoff in the river.The maximum daily runoff reached 70 times that before rains.The maximum daily fluxes of DIN and DIP were 109 and 247 times that before rains,respectively.In view that the watershed experienced several rainstorms in the wet season,the river,with pulse runoff,carries a large amount of nutrients into the sea in a short time,which will have a significant impact on the environment of Sanmen bay and its adjacent sea.
2024年02期 v.23 383-391页 [查看摘要][在线阅读][下载 1924K] - ZHOU Zhiyu;LIU Mingxuan;JI Haodong;WANG Yaming;ZHU Zefei;
The ocean plays an important role in maintaining the equilibrium of Earth's ecology and providing humans access to a wealth of resources.To obtain a high-precision underwater image classification model,we propose a classification model that combines an EfficientnetB0 neural network and a two-hidden-layer random vector functional link network(EfficientnetB0-TRVFL).The features of underwater images were extracted using the EfficientnetB0 neural network pretrained via ImageNet,and a new fully connected layer was trained on the underwater image dataset using the transfer learning method.Transfer learning ensures the initial performance of the network and helps in the development of a high-precision classification model.Subsequently,a TRVFL was proposed to improve the classification property of the model.Net construction of the two hidden layers exhibited a high accuracy when the same hidden layer nodes were used.The parameters of the second hidden layer were obtained using a novel calculation method,which reduced the outcome error to improve the performance instability caused by the random generation of parameters of RVFL.Finally,the TRVFL classifier was used to classify features and obtain classification results.The proposed EfficientnetB0-TRVFL classification model achieved 87.28%,74.06%,and 99.59% accuracy on the MLC2008,MLC2009,and Fish-gres datasets,respectively.The best convolutional neural networks and existing methods were stacked up through box plots and Kolmogorov-Smirnov tests,respectively.The increases imply improved systematization properties in underwater image classification tasks.The image classification model offers important performance advantages and better stability compared with existing methods.
2024年02期 v.23 392-404页 [查看摘要][在线阅读][下载 3241K] - GAI Lei;LI Wendong;WANG Guoyu;
This study explores the application of single photon detection(SPD) technology in underwater wireless optical communication(UWOC) and analyzes the influence of different modulation modes and error correction coding types on communication performance.The study investigates the impact of on-off keying(OOK) and 2-pulse-position modulation(2-PPM) on the bit error rate(BER)in single-channel intensity and polarization multiplexing.Furthermore,it compares the error correction performance of low-density parity check(LDPC) and Reed-Solomon(RS) codes across different error correction coding types.The effects of unscattered photon ratio and depolarization ratio on BER are also verified.Finally,a UWOC system based on SPD is constructed,achieving 14.58 Mbps with polarization OOK multiplexing modulation and 4.37 Mbps with polarization 2-PPM multiplexing modulation using LDPC code error correction.
2024年02期 v.23 405-414页 [查看摘要][在线阅读][下载 2486K] - LI Jing;LIU Kai;WEI Zhengrong;ZHANG Liancheng;LIU Yangting;PEI Yanliang;LIU Chenguang;LIU Baohua;
The near-seabed multichannel seismic exploration systems have yielded remarkable successes in marine geological disaster assessment,marine gas hydrate investigation,and deep-sea mineral exploration owing to their high vertical and horizontal resolution.However,the quality of deep-towed seismic imaging hinges on accurate source-receiver positioning information.In light of existing technical problems,we propose a novel array geometry inversion method tailored for high-resolution deep-towed multichannel seismic exploration systems.This method is independent of the attitude and depth sensors along a deep-towed seismic streamer,accounting for variations in seawater velocity and seabed slope angle.Our approach decomposes the towed line array into multiline segments and characterizes its geometric shape using the line segment distance and pitch angle.Introducing optimization parameters for seawater velocity and seabed slope angle,we establish an objective function based on the model,yielding results that align with objective reality.Employing the particle swarm optimization algorithm enables synchronous acquisition of optimized inversion results for array geometry and seawater velocity.Experimental validation using theoretical models and practical data verifies that our approach effectively enhances source and receiver positioning inversion accuracy.The algorithm exhibits robust stability and reliability,addressing uncertainties in seismic traveltime picking and complex seabed topography conditions.
2024年02期 v.23 415-426页 [查看摘要][在线阅读][下载 6386K] - KOU Hailei;HUANG Jiaming;CHENG Yang;
Structure-soil interface friction characteristics is of importance to investigate the interaction between engineering structures and soils,especially for offshore structures.The interface friction behavior between marine clay and structural materials with different roughness was studied in this paper by using 3D optical scanning tests,a modified direct shear device and numerical simulation.Relationships between the surface roughness of structures,water content and interface friction angle were presented by model tests.The increase of water contents decreased the interface friction angles.For interfaces with different roughness,the interface friction angles will be smaller than that of the soil when the water content exceeds a certain value.The roughness of the interface and the water content of the soil are mutually coupled to influence the coefficient of friction(COF).This paper proposed a Finite Element Method(FEM)to simulate the interface direct shear tests of structures with different roughness.The surface models with different roughness are established based on the structure data obtained by 3D scanning.The Coupled Eulerian-Lagrangian(CEL) approach was employed to analyse soils sheared by irregular surfaces.The interface behavior for interfaces with different roughness under cyclic shear stresses was analyzed by FEM.
2024年02期 v.23 427-437页 [查看摘要][在线阅读][下载 4485K] - LV Honggang;JIANG Yifei;WANG Haiyan;
Using the observation data in Yongxing Island,South China Sea(SCS) from December 2013 to November 2018,the multiple time scales variation of atmospheric CO_2 and CH_4 were analyzed to understand their temporal variation characteristics and controlling factors.The regional-averaged background mole fractions of CO_2 and CH_4 both show a single-period sinusoidal variation with a lower value at noon and a higher value in the wee hours.In the seasonal scale,they exhibited a significant seasonal difference with higher values in winter and lower values in summer.In the annual scale,CO_2 and CH_4 both show an increasing trend,with an annual growth rate of approximately 3.2 ppm and 12 ppb,respectively.The annual growth rate at this site was higher than the global average.The change in atmospheric CO_2 and CH_4 in Yongxing Island was probably caused by the higher emission of the surrounding areas and the airflows driven by monsoon.Hopefully,the long-term and high-resolution greenhouse gases(GHGs) dataset will aid relevent researchers and decision-makers in performing more in-depth studies for GHG sources in order to derive effective strategies.
2024年02期 v.23 438-446页 [查看摘要][在线阅读][下载 3480K] - ZHAO Xuning;ZHANG Zhiming;ZHAO Yangguo;MUPINDU Progress;
The production of toxic sulfides is a common environmental problem in mariculture.Therefore,the effective inhibition of sulfidogens is the key to prevent sulfides production.In this study,the possibility and mechanism of nitrate(NO_3~-) inhibiting the activity of the sulfate-reducing microbiota(SRM) from mariculture sediments was investigated.The results showed that 1,3,and 5 mmol L~(-1) NO_3~- continuously inhibited sulfide production for 1–3 d.As NO_3~- dosage increased to 7 mmol L~(-1),the duration of inhibition increased to 6 days.Denitrifying product NO_2~- heavily inhibited the activity of dissimilar sulfate reductase gene(dsr B) by 3 orders,which was the main reason that the sulfate-reducing activity was inhibited.The SRM structure changed significantly with the dosage of NO_3~-,while the abundance of sulfidogens Desulfovibrio species increased due to their capability of detoxifying nitrite through nitrite reductase.Hence,sulfidogens Desulfovibrio species are more adaptable to a high nitrate/nitrite environment,and the traditional control strategies by dosing nitrate/nitrite should be paid more attention to.The findings will serve as helpful guidelines for sulfate-reducing microbiota in the habitat of mariculture to reduce their generation of poisonous sulfide.
2024年02期 v.23 447-454页 [查看摘要][在线阅读][下载 1150K] - LIU Xiao;JIANG Xueyan;LIU Qian;SUI Juanjuan;ZOU Li;
As a river with more than 3000 reservoirs in its watershed,the Yellow River has been affected by dams not only on the sediment load,but also on the water quality.Water-sediment regulation scheme(WSRS),which has been carried out annually in the Yellow River since 2002,is a typical human activity affecting river water quality.Chromophoric dissolved organic matter(CDOM)in river is susceptible to changes in ecological and environmental conditions as well as human activities.Here,we report variations in dissolved organic carbon concentrations,compositions and sources of CDOM in time series samples in the lower Yellow River during WSRS.In addition,a parallel factor fluorescence analysis(PARAFAC) method is applied to identify different fluorescent components in water samples during WRSR,showing four major components including tryptophan-like component(C1),microbial humic-like component(C2),terrestrial humic-like component(C3) and tyrosine-like component(C4).In general,C1 increased after water regulation,while C2 and C3 increased after sediment regulation,indicating that the water and sediment released by the dam have different effects on CDOM compositions.Under the impacts of the dam,source of CDOM in the lower Yellow River is mainly autochthonous related to microbial activities,and is regulated by the terrestrial input during WSRS period.Sediment resuspension inhibits microbial activities and reduces the production of autochthonous CDOM.Overall,human activities especially WSRS,as exemplified here,significantly alter the quality and quantity of CDOM in the lower Yellow River,affecting CDOM dynamics and biogeochemical processes in the estuarine environment.
2024年02期 v.23 455-466页 [查看摘要][在线阅读][下载 1764K] - SUN Wenting;HU Yangdong;ZHENG Jiahuan;SUN Qichao;Chen Xia;DING Jiakun;ZHANG Weitao;WU Lianying;
Studying the relationship between ionic interactions and salt solubility in seawater has implications for seawater desalination and mineral extraction.In this paper,a new method of expressing ion-to-ion interaction is proposed by using molecular dynamics simulation,and the relationship between ion-to-ion interaction and salt solubility in a simulated seawater water-salt system is investigated.By analyzing the variation of distance and contact time between ions in an electrolyte solution,from both spatial and temporal perspectives,new parameters were proposed to describe the interaction between ions:interaction distance(ID),and interaction time ratio(ITR).The best correlation between characteristic time ratio and solubility was found for a molar ratio of salt-to-water of 10:100 with a correlation coefficient of 0.96.For the same salt,a positive correlation was found between CTR and the molar ratio of salt and water.For type 1-1,type 2-1,type 1-2,and type 2-2 salts,the correlation coefficients between CTR and solubility were 0.93,0.96,0.92,and 0.98 for a salt-to-water molar ratio of 10:100,respectively.The solubility of multiple salts was predicted by simulations and compared with experimental values,yielding an average relative deviation of 12.4%.The new ion-interaction parameters offer significant advantages in describing strongly correlated and strongly hydrated electrolyte solutions.
2024年02期 v.23 467-476页 [查看摘要][在线阅读][下载 1078K]
- XIAO Yao;LI Jiacheng;TIAN Qianqian;WU Baolan;HAN Fang;
Lysozyme(EC3.2.1.17) plays an important role in the immune response;as a nonspecific immune factor,it can resist causative agents.Lysozyme can be divided into c-type and g-type in fish.In a previous study,through genome-wide association analysis,the g-type lysozyme gene,which is named NaLyg in yellow drum(Nibea albiflora),was found to be a key candidate gene for disease resistance in response to Vibrio harveyi infection.The cDNA of NaLyg was 1025 bp,including four exons and three introns,and its open reading frame(ORF) had a full-length of 582 bp,encoding 193 amino acids.NaLyg was found to be conserved during evolution through bioinformatic analyses.The NaLyg protein possessed a sugar binding domain and three catalytic sites,including Glu71,Asp84and Asp101.Quantitative qRT-PCR results confirmed that NaLyg gene mRNA was visibly increased after V.harveyi infection.The NaLyg protein purified by prokaryotic expression killed some gram-negative bacterial pathogens by inducing cell wall destruction,including V.harveyi,Aeromonas hydrophila and Edwardsiella tarda.Moreover,the NaLyg protein killed two gram-positive bacteria,Bacillus subtilis and Staphylococcus aureus.Taken together,the experimental results suggested that the NaLyg protein of N.albiflora played an important role in fighting bacterial infections.
2024年02期 v.23 477-486页 [查看摘要][在线阅读][下载 2265K] - LIU Zhiying;NIU Jingning;ZHAO Xi;LIU Huaxiang;LI Zibin;HE Yan;QI Jie;
Black rockfish(Sebastes schlegelii) has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months until the egg mature in ovary,while the adaptive evolution of fertilization-related genes remains to be studied.In the present study,based on the genome and transcriptome information of black rockfish,a total of 10 hyaluronidase genes were identified by phylogenetic and sequence analyses,including hyal1,hyal2,hyal3,hyal4,hyal6 and spam1a,spam1b,spam1c and spam1d.The spam1 subfamilies,including spam1a,spam1b,spam1c and spam1d,were significantly expanded compared to other species.The adaptive evolution of hyaluronidase was further investigated by selection pressure analysis of branch model and branch site model.The results showed that only spam1 subfamily was positively selected with a large number of positive selection sites,and the evolution rate was significantly higher thanthose of other teleosts.Two positively selected sites,LYS-171 and GLY-164,were located in the neutral hyaluronidase activity domain,which was pivotal for SPAM1 to participate in enzymatic hydrolysis of the extracellular hyaluronic acid matrix and mediate acrosome reaction in mammals.Furthermore,spam1 was mainly expressed in spermatocytes,secondary spermatocytes,and spermatids of testis,whereas it was not found in metamorphic sperm and mature sperm based on the spatiotemporal expression analysis.All results indicated that spam1 might originate from the testis and might be an adaptation of viviparous trait in black rockfish.
2024年02期 v.23 487-498页 [查看摘要][在线阅读][下载 5840K] - QIU Jiayin;SUN Lianlian;LI Shuang;ZHOU Xu;CHI Changfeng;ZHENG Libing;
Neuropeptides are widely distributed in vertebrates and invertebrates,regulating a variety of physiological activities in the organisms,such as metabolism,feeding and reproduction.In this study,to explore the function of neuropeptide LFRFamide in Sepia pharaonis,the full-length cDNA of LFRFamide-like gene(named Sp LFRFL,MG869822.1) was identified with rapid amplification of c DNA ends(RACE) method.The sequence of SpLFRFL was 860 bp in length and encoded 188 amino acids containing 4 different mature peptides:1 copy of PHTPFRFamide,NSLFRFamide,TIFRFamide,and 3 copies of GNLFRFamide.Multiple alignment and phylogenetic analysis results showed that Sp LFRFL shared high identity with LFRFamides of Sepia officinalis and Sepiella japonica and had the closest relationship with them.Through quantitative Real-time PCR(qRT-PCR),it was found that the Sp LFRFL gene was highly expressed in the optic lobe and brain at three different stages during gonad development in both genders.Moreover,the four mature peptides at a concentration of 0.01 μmol L-1 could inhibit the protein synthesis in the Chinese hamster ovary cell strain-K1(CHOK1) induced by Sp Gn RH.These data suggest that SpLFRFL might be involved in the development and reproduction of S.pharaonis.The results can contribute to future studies on neuropeptide evolution and function and benefit the cuttlefish farming.
2024年02期 v.23 499-508页 [查看摘要][在线阅读][下载 3297K] - JIAO Lin;LIANG Shufei;CHU Ruixia;WANG Wentao;MAI Kangsen;LIU Ming;WAN Min;
In recent years probiotics have been considered as a potential substitution of antibiotics to control pathogens and treat infectious diseases in aquaculture.In the present study a strain of Lactobacillus pentosus,named as L.pentosus SF-1,was isolated from waters in aquaculture.The species identification of this strain was conducted by 16S r RNA sequence,and the physiological and biochemical characteristics of this strain were assessed.Furthermore,the virulence,antibiotic sensitivity,cell surface characteristics and acid/base-resistance of L.pentosus SF-1 were determined to evaluate the probiotic potentials of this strain.Specifically,L.pentosus SF-1 is sensitive to most common antibiotics,and no hemolysin was generated from it,indicating the safety of this strain to hosts.In addition,L.pentosus SF-1 was able to tolerate the artificial gastric juice at p H 3 for 4 h and the artificial intestinal fluid at p H 6.8 or 8.0 for 6 h.Moreover,the analysis of self-aggregation and the adhesion of L.pentosus SF-1 to organic solvents suggested a high potential of L.pentosus SF-1 to inhabit the hosts,which was confirmed by testing the colonization of L.pentosus SF-1 in germ-free zebrafish.Interestingly,L.pentosus SF-1 displayed a high bactericidal activity against several bacterial pathogens.Consistently,the incubation of L.pentosus SF-1 significantly promoted the expression of antimicrobial components in zebrafish,contributing to the protection of the fish from E.tarda infection in vivo.Taken together,the probiotic strain L.pentosus SF-1 could be applied as anti-infection reagent in aquaculture.
2024年02期 v.23 509-517页 [查看摘要][在线阅读][下载 1373K] - HU Boyang;TIAN Yuan;LIU Shikai;LI Qi;
Pacific oyster(Crassostrea gigas) is one of the most important mollusks cultured all around the world.Selective breeding programs of Pacific oysters in China is initiated since 2006 and developed the genetically improved strain with fast-growing trait.However,little is known about the metabolic signatures of the fast-growing trait.In the present study,the non-targeted metabolomics was performed to analyze the metabolic signatures of adductor muscle tissue in one-year old Pacific oysters from fast-growing strain and the wild population.A total of 7767 and 10174 valid peaks were extracted and quantified in ESI+ and ESI-modes,resulting in 399 and 381 annotated metabolites,respectively.PCA and OPLS-DA revealed that considerable separation among samples from fastgrowing strain and wild population,suggesting the differences in metabolic signatures.Meanwhile,81 significantly different metabolites(SDMs) were identified in the comparisons between fast-growing strain and wild population,based on the strict thresholds.It was found that there were highly correlation and conserved coordination among these SDMs.KEGG enrichment analysis indicated that the SDMs were tightly related to pantothenate and CoA biosynthesis,steroid hormone biosynthesis,riboflavin metabolism,and arginine and proline metabolism.Of them,the CoA biosynthesis and metabolism,affected by pantetheine and pantothenic acid,might be important for the growth of Pacific oysters under artificial selective breeding.The study provides the comprehensive views of metabolic signatures in response to artificially selective breeding,and is helpful to better understand the molecular mechanism of fastgrowing traits in Pacific oysters.
2024年02期 v.23 518-528页 [查看摘要][在线阅读][下载 2236K] - YANG Huijie;HUANG Xianghu;MA Yukun;HU Zhangxi;ZHANG Ning;LI Changling;ZHANG Yulei;
Alexandrium pacificum(A.pacificum) is a typical paralytic shellfish poisonous dinoflagellate.Harmful algal blooms(HABs)caused by this species can bring serious environmental problems and economic losses to the aquaculture industry.In this study,transcriptome sequencing and analyses were performed on the neural tissue of Litopenaeus vannamei(L.vannamei) after acute exposure to A.pacificum disrupted solution for 72 h,and differentially expressed genes(DEGs) were identified.The results showed that,compared with the control samples,300 DEGs were identified in the experimental group,of which 194 were up-regulated,and 106 down-regulated.The gene ontology(GO) functional enrichment analysis showed that DEGs were significantly enriched in the cortical cytoskeleton organization,troponin complex,amylo-alpha-1,6-glucosidase and thymidine phosphorylase.Kyoto encyclopedia of genes and genomes(KEGG) enrichment analysis found that DEGs were mainly enriched in the oxidative phosphorylation process,intercellular tight junctions and mitophagy.The results showed that the proteoglycans,signaling pathways,and various metabolic processes that regulate cell proliferation,differentiation,and apoptosis all played an essential role in the response of L.vannamei to A.pacificum toxins.
2024年02期 v.23 529-538页 [查看摘要][在线阅读][下载 800K] - JI Xin;BI Luping;ZOU Songbao;LI Wenlu;JI Daode;ZHANG Qianqian;
Coastal and estuarine protists are frequently exposed to salinity undulation.While the tolerance and stress responses of microalgae to salinity have been extensively studied,there have been scarce studies on the physiological response of heterotrophic protists to salinity stressing.In this study,we investigated the physiological response of the heterotrophic ciliate Gastrostyla setifera to a salinity of 3,via a transcriptomic approach.The first transcriptome of genus Gastrostyla was obtained utilizing a group of manually isolated ciliate individuals(cells) and RNA-seq technique.The completeness of the transcriptome was verified.Differentially expressed gene(DEG) analysis was performed among the transcriptomes of G.setifera acclimated in saline water(salinity 3) and those cultured in fresh water.The results demonstrated a significant alternation in gene transcription,in which the ciliate exhibits a transcripttomic acclimation in responding salinity stressing.The up-regulated DEGs were enriched in the pathways of cytoskeleton proteins,membrane trafficking,protein kinases and protein phosphatases.These may represent enhanced functions of ion transport,stress response and cell protections.Pathways involved in energy metabolism and biosynthesis were markedly down-regulated,reflecting decreased cell activity.Particularly,we detected significantly down-regulated genes involved in several pathways of amino acid catabolism,which may lead to accumulation of amino acids in the ciliate cell.Amino acid could act as compatible solutes in the cytoplasm to maintain the osmotic balance in saline water.Overall,this work is an initial exploration to the molecular basis of the heterotrophic protist responding to salinity stressing.The result sheds light on the mechanisms of enhancement of cell protection,reduction of cell activity,and osmotic pressure regulation in ciliates acclimated to salinity.
2024年02期 v.23 539-549页 [查看摘要][在线阅读][下载 2560K] - SUN Taohua;LIU Jie;YAN Taishan;CHEN Anjin;ZHANG Fang;
This study was carried out explore the mechanism underlying the inhibition of platelet activation by kelp fucoidans in deep venous thrombosis(DVT) mouse.In the control and sham mice,the walls of deep vein were regular and smooth with intact intima,myometrium and adventitia.The blood vessel was wrapped with the tissue and there was no thrombosis in the lumen.In the DVT model,the wall was uneven with thicken intima,myometrium and adventitia.After treated with fucoidans LF1 and LF2,the thrombus was dissolved and the blood vessel was recanalized.Compared with the control group,the ROS content,ET-1 and VWF content and the expression of PKC-β and NF-κB in the model were significantly higher(P < 0.05);these levels were significantly reduced following treatments with LF2 and LF1.Compared with H_2O_2 treated-HUVECs,combined LF1 and LF2 treatment resulted in significant decrease in the expression of PKC-β,NF-κB,VWF and TM protein(P < 0.05).It is clear that LF1 and LF2 reduces DVT-induced ET-1,VWF and TM expressions and production of ROS,thus inhibiting the activation of PKC-β/NF-κB signal pathway and the activation of coagulation system and ultimately reducing the formation of venous thrombus.
2024年02期 v.23 550-556页 [查看摘要][在线阅读][下载 1290K] - CAO Huimin;WANG Ping;ZHANG Surong;XU Dongpo;TIAN Weijun;
This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,China.Based on panel data spanning 2011 – 2020,a vector autoregressive(VAR) model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic development.The results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic index.Per capital chemical oxygen demand(PCOD) and per capita ammonia nitrogen(PNH3N) had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR) and delta tertiary industry(dTIR) had a negative impact on dPGDP.The VAR model under this coupling system had stability and credibility.The impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test results.In addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration.
2024年02期 v.23 557-566页 [查看摘要][在线阅读][下载 1371K] 下载本期数据