In this paper, we established a finite element (FEM) model to analyze the dynamic characteristics of arch bridges. In this model, the effects of adjustment to the length of a suspender on its geometry stiffness matrix...In this paper, we established a finite element (FEM) model to analyze the dynamic characteristics of arch bridges. In this model, the effects of adjustment to the length of a suspender on its geometry stiffness matrix are stressed. The FEM equations of mechanics characteristics, natural frequency and main mode are set up based on the first order matrix perturbation theory. Applicantion of the proposed model to analyze a real arch bridge proved the improvement in the simulation precision of dynamical characteristics of the arch bridge by considering the effects of suspender length variation.展开更多
Based on the mechanical model of an elastic rod,a new trajectory design method was established.The advantages of the suspender line trajectory in reducing drag and torsion were compared,and the main controlling factor...Based on the mechanical model of an elastic rod,a new trajectory design method was established.The advantages of the suspender line trajectory in reducing drag and torsion were compared,and the main controlling factors of drag and torque and their influence rules were analyzed.Research shows that the suspender line trajectory reduces drag and torque more effectively than the conventional trajectory in a certain parameter interval and has more controllable parameters than that of the catenary trajectory.The main factors affecting the drag reduction and torque reduction of the suspender line trajectory include the friction coefficient,vertical distance,horizontal distance,and deviation angle at the initial point in the suspended section.The larger the friction coefficient and deviation angle,the less the drag reduction and torque reduction.The suspender line trajectory has the best drag reduction effect when the horizontal and vertical distances are more than 3000 m and the ratio is close to 1.5.The drag in sliding drilling can be reduced up to 60%,and the torque in rotary drilling can be reduced by a maximum of 40%.Therefore,the trajectory design of the suspender line has unique application prospects in deep extended-reach wells.展开更多
Accurate daily suspended sediment load(SSL)prediction is essential for sustainable water resource management,sediment control,and environmental planning.However,SSL prediction is highly complex due to its nonlinear an...Accurate daily suspended sediment load(SSL)prediction is essential for sustainable water resource management,sediment control,and environmental planning.However,SSL prediction is highly complex due to its nonlinear and dynamic nature,making traditional empirical models inadequate.This study proposes a novel hybrid approach,integrating the Adaptive Neuro-Fuzzy Inference System(ANFIS)with the Gradient-Based Optimizer(GBO),to enhance SSL forecasting accuracy.The research compares the performance of ANFIS-GBO with three alternative models:standard ANFIS,ANFIS with Particle Swarm Optimization(ANFIS-PSO),and ANFIS with Grey Wolf Optimization(ANFIS-GWO).Historical SSL and streamflow data from the Bailong River Basin,China,are used to train and validate the models.The input selection process is optimized using the Multivariate Adaptive Regression Splines(MARS)method.Model performance is evaluated using statistical metrics such as Root Mean Square Error(RMSE),Mean Absolute Error(MAE),Mean Absolute Percentage Error(MAPE),Nash Sutcliffe Efficiency(NSE),and Determination Coefficient(R^(2)).Additionally,visual assessments,including scatter plots,Taylor diagrams,and violin plots,provide further insights into model reliability.The results indicate that including historical SSL data improves predictive accuracy,with ANFIS-GBO outperforming the other models.ANFIS-GBO achieves the lowest RMSE and MAE and the highest NSE and R^(2),demonstrating its superior learning ability and adaptability.The findings highlight the effectiveness of nature-inspired optimization algorithms in enhancing sediment load forecasting and contribute to the advancement of AI-based hydrological modeling.Future research should explore the integration of additional environmental and climatic variables to enhance predictive capabilities further.展开更多
Urban transportation systems are facing severe challenges due to the rapid growth of the urban population,especially in China.Suspended monorail system(SMS),as a sky rail transportation form,can effectively alleviate ...Urban transportation systems are facing severe challenges due to the rapid growth of the urban population,especially in China.Suspended monorail system(SMS),as a sky rail transportation form,can effectively alleviate urban traffic congestion due to its independent right-of-way and minimal ground footprint.However,the SMS possesses a special traveling system with unique vehicle structure and bridge configuration,which results in significant differences in both the mechanisms and dynamics problems associated with train–bridge interaction(TBI)when contrasted with those of traditional railway systems.Therefore,a thorough understanding of the SMS dynamics is essential for ensuring the operational safety of the system.This article presents a state-of-the-art review of the TBI modeling methodologies,critical dynamic features,field tests,and practice of the SMS in China.Firstly,the development history,technical features,and potential dynamics problems of the SMS are briefly described,followed by the mechanical characteristics and mechanisms of the train–bridge interactive systems.Then,the modeling methodology of the fundamental elements in the suspended monorail TBI is systematically reviewed,including the suspended train subsystem,bridge subsystem,train–bridge interaction relationships,system excitations,and solution method.Further,the typical dynamic features of the TBI under various operational scenarios are elaborated,including different train speeds,a variety of line sections,and a natural wind environment.Finally,the first new energy-based SMS test line in the world is systematically introduced,including the composition and functionality of the system,the details of the conducted field tests,and the measured results of the typical dynamic responses.At the end of the paper,both the guidance on further improvement of the SMS and future research topics are proposed.展开更多
This study investigates the nonlinear resonance responses of suspended cables subjected to multi-frequency excitations and time-delayed feedback.Two specific combinations and simultaneous resonances are selected for d...This study investigates the nonlinear resonance responses of suspended cables subjected to multi-frequency excitations and time-delayed feedback.Two specific combinations and simultaneous resonances are selected for detailed examination.Initially,utilizing Hamilton’s variational principle,a nonlinear vibration control model of suspended cables under multi-frequency excitations and longitudinal time-delayed velocity feedback is developed,and the Galerkin method is employed to obtain the discrete model.Subsequently,focusing solely on single-mode discretization,analytical solutions for the two simultaneous resonances are derived using the method of multiple scales.The frequency response equations are derived,and the stability analysis is presented for two simultaneous resonance cases.The results demonstrate that suspended cables exhibit complex nonlinearity under multi-frequency excitations.Multiple solutions under multi-frequency excitation can be distinguished through the frequency–response and the detuning-phase curves.By adjusting the control gain and time delay,the resonance range,response amplitude,and phase of suspended cables can be modified.展开更多
Aiming at the pain points of visually impaired people during travel,this research innovatively transforms an industrial quadruped robot into a guide dog device.By transplanting the PCS-9180 motion control system(1.7 m...Aiming at the pain points of visually impaired people during travel,this research innovatively transforms an industrial quadruped robot into a guide dog device.By transplanting the PCS-9180 motion control system(1.7 m/s,IP66),and integrating a multi-modal perception network with a lightweight YOLO11 model.Tests show that the pass-through rate in complex terrains is 98%,the response delay is 0.3 seconds,and the cost is 50%that of a guide dog.The research verifies the social value of the transformation of industrial robot technology.展开更多
Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating...Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.展开更多
Mesoscale eddies are widespread in the global ocean,significantly influencing the physical,chemical,and biological structures of water column.Based on the CTD data and suspended particulate matter(SPM)data collected a...Mesoscale eddies are widespread in the global ocean,significantly influencing the physical,chemical,and biological structures of water column.Based on the CTD data and suspended particulate matter(SPM)data collected at 36 hydrographic stations during a field cruise in southern Mozambique Channel,combined with satellite altimeter observations,we identified a series of mesoscale eddies traversing the Mozambique Channel.Our hydrographic measurements,coupled with in situ chlorophyll fluorescence data,reveal that these eddies significantly influence thermohaline structure and chlorophyll distribution,which in turn affects primary productivity and SPM concentrations in the upper ocean.The cyclonic eddies facilitate the upwelling of cold subsurface water,leading to a shallowing of the pycnocline and the creation of a low-temperature anomaly with variable salinity anomalies at different depths.Conversely,anticyclonic eddies submerge warm surface water,deepening the pycnocline,and resulting in a high-temperature anomaly accompanied by distinct salinity patterns.Significantly,a coastal anticyclonic eddy was observed to intercept terrestrial material from the Delagoa Bight,redirecting it west of 36°E.This study presents unique and quasi-synchronous CTD datasets capturing mesoscale eddy impacts,and provided valuable insights into SPM variability within the often-neglected southern Mozambique Channel.展开更多
Ocean remote sensing satellites provide observations with high spatiotemporal resolution.However,the influence of clouds,fog,and haze frequently leads to significant data gaps.Accurate and effective estimation of thes...Ocean remote sensing satellites provide observations with high spatiotemporal resolution.However,the influence of clouds,fog,and haze frequently leads to significant data gaps.Accurate and effective estimation of these missing data is highly valuable for engineering and scientific research.In this study,the radial basis function(RBF)method is used to estimate the spatial distribution of total suspended matter(TSM)concentration in Hangzhou Bay using remote sensing data with severe data gaps.The estimation precision is validated by comparing the results with those of other commonly used interpolation methods,such as the Kriging method and the basic spline(B-spline)method.In addition,the applicability of the RBF method is explored.Results show that the estimation of the RBF method is significantly close to the observation in Hangzhou Bay.The average of the mean absolute error,mean relative error,and root mean square error in all the experiments is evidently smaller than those of the Kriging and B-spline interpolations,indicating that the proposed method is more appropriate for estimating the spatial distribution of the TSM in Hangzhou Bay.Finally,the TSM distribution in the blank observational area is predicted.This study can provide some reference values for handling watercolor remote sensing data.展开更多
Electric desalting wastewater(EDW)is one of the petrochemical wastewater generated in the production process of petrochemical industry,due to the instability of its water quality,the traditional wastewater treatment t...Electric desalting wastewater(EDW)is one of the petrochemical wastewater generated in the production process of petrochemical industry,due to the instability of its water quality,the traditional wastewater treatment technology is complex,high energy consumption,and will produce waste causing secondary pollution,posing challenges in terms of environmental protection,technology,and economy.This study utilized an on-site test to investigate the possibility of a new short-process physical method to replace traditional electro-chemical,oil-separation,and two-stage air floating physical chemistry processes,in response to optimizing the treatment effect,thus reducing the cost of treatment and carbon emissions.Following this test,this new short-flow physical method process could improve the efficiency of oil and suspend solid(SS)removal by 15.48%and 58.72%,and providing 78.37%and 75.55%the operating costs and carbon emissions savings,respectively.This system also reduced the production of waste solids,volatile organic compounds,and other three-waste compared with the traditional process.These benefits offer environmental and economic advantages,and this process serves as an efficient strategy to treat wastewater for electric desalination,and can be served as a completely new technological and process option for the treatment of EDW.展开更多
The concentrations of polycyclic aromatic hydrocarbons(PAHs),their sources and toxic equivalent(TEQ)in soil,suspended matter and bottom sediments in the Fatala River Basin ecosystem were obtained for the fi rst time t...The concentrations of polycyclic aromatic hydrocarbons(PAHs),their sources and toxic equivalent(TEQ)in soil,suspended matter and bottom sediments in the Fatala River Basin ecosystem were obtained for the fi rst time to our knowledge.Determination of 14 PAHs(ΣPAHs)was carried out using high-performance liquid chromatography.TheΣPAH content in soil ranged from 13 to 50,920(Me=820)ng/g.The composition of PAHs(high proportion of low-molecular-weight compounds and values of individual PAHs ratios)refl ected the signifi cant oil pollution of soil.Contaminated soil was localated in the central part of the Fatala River Basin.The median benzo(a)pyrene toxic equivalent of soil at the study site was 1.08(range,0.05 to 53.16)ngTEQ/g,showing generally low soil toxicity.TheΣPAH content in suspended matter was in the range of 33 to 1316(Me=309)ng/L.TheΣPAH content in bottom sediments ranged from 36 to 6943(Me=478)ng/L,corresponding to clean and moderately contaminated sediments.TheΣPAH content in bottom sediments depended on the anthropogenic impact on the Fatala River Basin territory and the bottom sediment features.Bottom sediments and suspended matter had a low toxic equivalent.展开更多
According to some main assumptions in the Rouse Formula,it analyzes the applicability of Rouse distribution in the coastal region.Based on the classical Rouse Formula,the linear form of Rouse Formula and the transport...According to some main assumptions in the Rouse Formula,it analyzes the applicability of Rouse distribution in the coastal region.Based on the classical Rouse Formula,the linear form of Rouse Formula and the transport characteristics of offshore sediment were used to take lnz/h,lnc_(a),c_(a),u,lnu and z/h as the independent variables.The multiple liner regression method was used to analyze the influence of the independent variables on the vertical distribution of sediment concentration.By using the method of significance test,the factors(ln𝑢)that have less influence on sediment concentration among 6 variables were eliminated.The correlation coefficient between the calculated sediment concentration and the measured sediment concentration indicates that the adopted variables can reflect the characteristics of vertical distribution of concentration of fine sediment near shore under complex dynamic conditions.展开更多
This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorp...This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorporating flexible appendages and an orthogonal cluster of magnetically suspended reaction wheel actuators is initially developed.After that,an adaptive attitude controller is designed with a switching surface of variable structure,an adaptive law for estimating inertia matrix uncertainty,and a fuzzy disturbance observer for estimating disturbance torques.Additionally,a Moore-Penrose-based steering law is proposed to derive the tilt angle commands of the orthogonal configuration of the 3D MSW to follow the designed control signal.Finally,numerical simulations are presented to validate the effectiveness of the proposed control strategy.展开更多
This review provides insight into the current research trend in transition metal oxides(TMOs)-based photocatalysis in removing the organic colouring matters from water.For easy understanding,the research progress has ...This review provides insight into the current research trend in transition metal oxides(TMOs)-based photocatalysis in removing the organic colouring matters from water.For easy understanding,the research progress has been presented in four generations according to the catalyst composition and mode of application,viz:single component TMOs(the firstgeneration),doped TMOs/binary TMOs/doped binary TMOs(the second-generation),inactive/active support-immobilized TMOs(the third-generation),and ternary/quaternary compositions(the fourth-generation).The first two generations represent suspended catalysts,the third generation is supported catalysts,and the fourth generation can be suspended or supported.The review provides an elaborated comparison between suspended and supported catalysts,their general/specific requirements,key factors controlling degradation,and the methodologies for performance evaluation.All the plausible fundamental and advanced dye degradation mechanisms involved in each generation of catalysts were demonstrated.The existing challenges in TMOs-based photocatalysis and how the researchers approach the hitch to resolve it effectively are discussed.Future research trends are also presented.展开更多
Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of g...Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals forces.However,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional semiconductors.Here,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)heterostructures.Electrons in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral range.By eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or hBN.Wefurther demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal equilibrium.Direct cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical excitation.It is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal radiation.The demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulators.展开更多
Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and ...Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and desorption.We analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year period.Results showed that medium silt(16–32µm)was the main component.As expected,the activity of each radionuclide decreased with an increase of particle size.We examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different sources.Our results indicate that fine SPM(<32µm)was mainly from the erosion of soil along the lower reaches of the Yellow River,while coarse SPM(>32µm)was mainly derived from resuspension of riverbed sediment.During high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream increased.Naturally occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea.展开更多
Global carbon cycle has received extensive attention,among which the river-estuary system is one of the important links connecting the carbon cycle between land and ocean.In this paper,the distribution and control fac...Global carbon cycle has received extensive attention,among which the river-estuary system is one of the important links connecting the carbon cycle between land and ocean.In this paper,the distribution and control factors of particulate organic carbon(POC)were studied by using the data of organic carbon contents and its carbon isotopic composition(δ13C)in the mainstream and estuary of Passur River in the Sundarbans area,combined with the hydrological and biological data measured by CTD.The results show that POC content ranged from 0.263 mg/L to 9.292 mg/L,and the POC content in the river section(averaged 4.129 mg/L)was significantly higher than that in the estuary area(averaged 0.858 mg/L).Two distinct stages of POC transport from land to sea in the Sundarbans area were identified.The first stage occurred in the river section,where POC distribution was mainly controlled by the dynamic process of runoff and the organic carbon was mainly terrestrial source.The second stage occurred during estuarine mixing,where the POC distribution was mainly controlled by the mixing process of seawater and freshwater.The source of POC was predominantly marine and exhibiting vertical differences.The surface and middle layers were primarily influenced by marine sources,while the bottom layer was jointly controlled by terrestrial and marine sources of organic carbon.These findings are of great significance for understanding the carbon cycle in such a large mangrove ecosystem like the Sundarbans mangrove.展开更多
The present study aimed to evaluate multi-element concentrations(Al,As,Ca,Cd,Co,Cr,Cu,Fe,Mg,Mn,Mo,Ni,Pb,Sr)in suspended particulate material(SPM)collected from Ensenada de La Paz(ELP)lagoon,Baja California Sur,Mexico ...The present study aimed to evaluate multi-element concentrations(Al,As,Ca,Cd,Co,Cr,Cu,Fe,Mg,Mn,Mo,Ni,Pb,Sr)in suspended particulate material(SPM)collected from Ensenada de La Paz(ELP)lagoon,Baja California Sur,Mexico in two different periods(September and May)to comprehend their origin,geochemical behavior,mass transfer and associated ecotoxicological risks.The 24 hr variation coefficient of volumetric SPM levels were found to be 51.7%in September and 40.5%in May,signifying the effects of oceanic waters.The calculated enrichment factor(EF)values for all the studied elements were of higher magnitude because of the high surface area and oxide nature of SPM,and in this study,Mo had the highest EF of 46.77 probably due to its origin from continental weathering.From the ecotoxicological perspective,the integrated toxic risk index revealed low toxic risk to the benthic community.However,the mean-ERM-Quotient calculated using the particulate concentrations of As,Cd,Cr,Cu,Ni,Pb indicated 9%probability of toxicity to biota.The comprehensive geochemical and ecotoxicological assessment of particulate metal concentrations in the ELP lagoon signify low to moderate contamination.展开更多
Wind erosion is a geomorphic process in arid and semi-arid areas and has substantial implications for regional climate and desertification.In the Columbia Plateau of northwestern United States,the emissions from fine ...Wind erosion is a geomorphic process in arid and semi-arid areas and has substantial implications for regional climate and desertification.In the Columbia Plateau of northwestern United States,the emissions from fine particles of loessial soils often contribute to the exceedance of inhalable particulate matter(PM)with an aerodynamic diameter of 10μm or less(PM10)according to the air quality standards.However,little is known about the threshold friction velocity(TFV)for particles of different sizes that comprise these soils.In this study,soil samples of two representative soil types(Warden sandy loam and Ritzville silt loam)collected from the Columbia Plateau were sieved to seven particle size fractions,and an experiment was then conducted to determine the relationship between TFV and particle size fraction.The results revealed that soil particle size significantly affected the initiation of soil movement and TFV;TFV ranged 0.304-0.844 and 0.249-0.739 m/s for different particle size fractions of Ritzville silt loam and Warden sandy loam,respectively.PM10 and total suspended particulates(TSP)emissions from a bed of 63-90μm soil particles were markedly higher for Warden sandy loam than for Ritzville silt loam.Together with the lower TFV of Warden sandy loam,dust emissions from fine particles(<100μm in diameter)of Warden sandy loam thus may be a main contributor to dust in the region's atmosphere,since the PM10 emissions from the soil erosion surfaces and its ensuing suspension within the atmosphere constitute an essential process of soil erosion in the Columbia Plateau.Developing and implementing strategic land management practices on sandy loam soils is therefore necessary to control dust emissions in the Columbia Plateau.展开更多
The design of a ship is a process facilitated by different parallel departments.Specialists from various disciplines jointly work on a project,eventually covering the entire process.Though simultaneously,these discipl...The design of a ship is a process facilitated by different parallel departments.Specialists from various disciplines jointly work on a project,eventually covering the entire process.Though simultaneously,these disciplines are often subject to a hierarchy,either clearly defined or dictated by necessity.Within these branches,despite a growing interest in enhancing the comfort on board ships,noise and vibration design is among the most sacrificed.Compared to hydrodynamic or structural modifications,efforts devoted to improving vibrational comfort are generally slightly impactful and costly.Consequently,these improvements are often relegated to the final stages of the design procedure.The underestimation of noise and vibrational comfort design can generate serious,unexpected issues emerging only in the advanced phases of the ship’s life,and post-construction interventions are often needed.This case is exemplified in the current study,where the crew of the research vessel Mintis,a catamaran-type hull,reported discomfort in the navigation wheelhouse.A measurement campaign was set up to assess the complaints of the operating personnel regarding the high vibrational levels.Subsequent to the measurements,a numerical simulation,specifically comprising a modal analysis,was conducted to investigate the nature of the disturbance and distinguish the underlying mechanism at its origin.This paper meticulously presents and discusses the strategy undertaken to analyze and solve the vibrational problem encountered on board,with particular attention to the criteria and the modeling considerations adopted.展开更多
基金Supported by the Key Teacher Foundation of Chongqing University (No. 717411067)
文摘In this paper, we established a finite element (FEM) model to analyze the dynamic characteristics of arch bridges. In this model, the effects of adjustment to the length of a suspender on its geometry stiffness matrix are stressed. The FEM equations of mechanics characteristics, natural frequency and main mode are set up based on the first order matrix perturbation theory. Applicantion of the proposed model to analyze a real arch bridge proved the improvement in the simulation precision of dynamical characteristics of the arch bridge by considering the effects of suspender length variation.
基金Supported by the National Science and Technology Major Project(2016ZX05060-014)PetroChina Major Science and Technology Project(ZD2019-183-005)。
文摘Based on the mechanical model of an elastic rod,a new trajectory design method was established.The advantages of the suspender line trajectory in reducing drag and torsion were compared,and the main controlling factors of drag and torque and their influence rules were analyzed.Research shows that the suspender line trajectory reduces drag and torque more effectively than the conventional trajectory in a certain parameter interval and has more controllable parameters than that of the catenary trajectory.The main factors affecting the drag reduction and torque reduction of the suspender line trajectory include the friction coefficient,vertical distance,horizontal distance,and deviation angle at the initial point in the suspended section.The larger the friction coefficient and deviation angle,the less the drag reduction and torque reduction.The suspender line trajectory has the best drag reduction effect when the horizontal and vertical distances are more than 3000 m and the ratio is close to 1.5.The drag in sliding drilling can be reduced up to 60%,and the torque in rotary drilling can be reduced by a maximum of 40%.Therefore,the trajectory design of the suspender line has unique application prospects in deep extended-reach wells.
基金supported by the National Natural Science Foundation of China(52350410465)the General Projects of Guangdong Natural Science Research Projects(2023A1515011520).
文摘Accurate daily suspended sediment load(SSL)prediction is essential for sustainable water resource management,sediment control,and environmental planning.However,SSL prediction is highly complex due to its nonlinear and dynamic nature,making traditional empirical models inadequate.This study proposes a novel hybrid approach,integrating the Adaptive Neuro-Fuzzy Inference System(ANFIS)with the Gradient-Based Optimizer(GBO),to enhance SSL forecasting accuracy.The research compares the performance of ANFIS-GBO with three alternative models:standard ANFIS,ANFIS with Particle Swarm Optimization(ANFIS-PSO),and ANFIS with Grey Wolf Optimization(ANFIS-GWO).Historical SSL and streamflow data from the Bailong River Basin,China,are used to train and validate the models.The input selection process is optimized using the Multivariate Adaptive Regression Splines(MARS)method.Model performance is evaluated using statistical metrics such as Root Mean Square Error(RMSE),Mean Absolute Error(MAE),Mean Absolute Percentage Error(MAPE),Nash Sutcliffe Efficiency(NSE),and Determination Coefficient(R^(2)).Additionally,visual assessments,including scatter plots,Taylor diagrams,and violin plots,provide further insights into model reliability.The results indicate that including historical SSL data improves predictive accuracy,with ANFIS-GBO outperforming the other models.ANFIS-GBO achieves the lowest RMSE and MAE and the highest NSE and R^(2),demonstrating its superior learning ability and adaptability.The findings highlight the effectiveness of nature-inspired optimization algorithms in enhancing sediment load forecasting and contribute to the advancement of AI-based hydrological modeling.Future research should explore the integration of additional environmental and climatic variables to enhance predictive capabilities further.
基金supported by the National Natural Science Foundation of China(Grant Nos.52202483,52108476,and 52388102)。
文摘Urban transportation systems are facing severe challenges due to the rapid growth of the urban population,especially in China.Suspended monorail system(SMS),as a sky rail transportation form,can effectively alleviate urban traffic congestion due to its independent right-of-way and minimal ground footprint.However,the SMS possesses a special traveling system with unique vehicle structure and bridge configuration,which results in significant differences in both the mechanisms and dynamics problems associated with train–bridge interaction(TBI)when contrasted with those of traditional railway systems.Therefore,a thorough understanding of the SMS dynamics is essential for ensuring the operational safety of the system.This article presents a state-of-the-art review of the TBI modeling methodologies,critical dynamic features,field tests,and practice of the SMS in China.Firstly,the development history,technical features,and potential dynamics problems of the SMS are briefly described,followed by the mechanical characteristics and mechanisms of the train–bridge interactive systems.Then,the modeling methodology of the fundamental elements in the suspended monorail TBI is systematically reviewed,including the suspended train subsystem,bridge subsystem,train–bridge interaction relationships,system excitations,and solution method.Further,the typical dynamic features of the TBI under various operational scenarios are elaborated,including different train speeds,a variety of line sections,and a natural wind environment.Finally,the first new energy-based SMS test line in the world is systematically introduced,including the composition and functionality of the system,the details of the conducted field tests,and the measured results of the typical dynamic responses.At the end of the paper,both the guidance on further improvement of the SMS and future research topics are proposed.
基金supported in part by the National Natural Science Foundation of China(Grant No.12432001)Natural Science Foundation of Hunan Province(Grant Nos.2023JJ60527,2023JJ30152,and 2023JJ30259)the Natural Science Foundation of Changsha(KQ2202133).
文摘This study investigates the nonlinear resonance responses of suspended cables subjected to multi-frequency excitations and time-delayed feedback.Two specific combinations and simultaneous resonances are selected for detailed examination.Initially,utilizing Hamilton’s variational principle,a nonlinear vibration control model of suspended cables under multi-frequency excitations and longitudinal time-delayed velocity feedback is developed,and the Galerkin method is employed to obtain the discrete model.Subsequently,focusing solely on single-mode discretization,analytical solutions for the two simultaneous resonances are derived using the method of multiple scales.The frequency response equations are derived,and the stability analysis is presented for two simultaneous resonance cases.The results demonstrate that suspended cables exhibit complex nonlinearity under multi-frequency excitations.Multiple solutions under multi-frequency excitation can be distinguished through the frequency–response and the detuning-phase curves.By adjusting the control gain and time delay,the resonance range,response amplitude,and phase of suspended cables can be modified.
文摘Aiming at the pain points of visually impaired people during travel,this research innovatively transforms an industrial quadruped robot into a guide dog device.By transplanting the PCS-9180 motion control system(1.7 m/s,IP66),and integrating a multi-modal perception network with a lightweight YOLO11 model.Tests show that the pass-through rate in complex terrains is 98%,the response delay is 0.3 seconds,and the cost is 50%that of a guide dog.The research verifies the social value of the transformation of industrial robot technology.
基金supported by the National Key Research and Development Program of China(No.2022YFC2805200)the National Natural Science Foundation of China(No.52373094)+4 种基金Zhejiang Provincial Natural Science Foundation(No.LR25E030004)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2023313)Sino-German Mobility Program(No.M-0424),Ningbo Major Research and Development Plan Project(No.20241ZDYF020148)Ningbo International Cooperation(No.2023H019)Ningbo Science&Technology Bureau(No.2024QL003)。
文摘Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.
基金Supported by the Taishan Scholar Project of Shandong Province (Nos.TS20190913,tsqn202211054)the Fundamental Research Funds for the Central Universities (No.202241007)the Youth Innovation Team Program in Colleges and Universities of Shandong Province (No.2022KJ045)
文摘Mesoscale eddies are widespread in the global ocean,significantly influencing the physical,chemical,and biological structures of water column.Based on the CTD data and suspended particulate matter(SPM)data collected at 36 hydrographic stations during a field cruise in southern Mozambique Channel,combined with satellite altimeter observations,we identified a series of mesoscale eddies traversing the Mozambique Channel.Our hydrographic measurements,coupled with in situ chlorophyll fluorescence data,reveal that these eddies significantly influence thermohaline structure and chlorophyll distribution,which in turn affects primary productivity and SPM concentrations in the upper ocean.The cyclonic eddies facilitate the upwelling of cold subsurface water,leading to a shallowing of the pycnocline and the creation of a low-temperature anomaly with variable salinity anomalies at different depths.Conversely,anticyclonic eddies submerge warm surface water,deepening the pycnocline,and resulting in a high-temperature anomaly accompanied by distinct salinity patterns.Significantly,a coastal anticyclonic eddy was observed to intercept terrestrial material from the Delagoa Bight,redirecting it west of 36°E.This study presents unique and quasi-synchronous CTD datasets capturing mesoscale eddy impacts,and provided valuable insights into SPM variability within the often-neglected southern Mozambique Channel.
基金supported by the Open Funds for Hubei Key Laboratory of Marine Geological Resources,China University of Geosciences(No.MGR202308)the Natural Science Foundation of Shandong Province(No.ZR2020MD085)+3 种基金the National Natural Science Foundation of China(No.41821004)the Taishan Scholar Program(No.tstp2022114)the Shandong Provincial Natural Science Foundation(No.DKXZZ202206)the National Key Research and Development Program of China(No.2016YFC1402404).
文摘Ocean remote sensing satellites provide observations with high spatiotemporal resolution.However,the influence of clouds,fog,and haze frequently leads to significant data gaps.Accurate and effective estimation of these missing data is highly valuable for engineering and scientific research.In this study,the radial basis function(RBF)method is used to estimate the spatial distribution of total suspended matter(TSM)concentration in Hangzhou Bay using remote sensing data with severe data gaps.The estimation precision is validated by comparing the results with those of other commonly used interpolation methods,such as the Kriging method and the basic spline(B-spline)method.In addition,the applicability of the RBF method is explored.Results show that the estimation of the RBF method is significantly close to the observation in Hangzhou Bay.The average of the mean absolute error,mean relative error,and root mean square error in all the experiments is evidently smaller than those of the Kriging and B-spline interpolations,indicating that the proposed method is more appropriate for estimating the spatial distribution of the TSM in Hangzhou Bay.Finally,the TSM distribution in the blank observational area is predicted.This study can provide some reference values for handling watercolor remote sensing data.
基金supported by the National Natural Science Foundation of China(Nos.52300086 and 52025103)the Postdoctoral Fellowship Program of CPSF(No.GZB20230215).
文摘Electric desalting wastewater(EDW)is one of the petrochemical wastewater generated in the production process of petrochemical industry,due to the instability of its water quality,the traditional wastewater treatment technology is complex,high energy consumption,and will produce waste causing secondary pollution,posing challenges in terms of environmental protection,technology,and economy.This study utilized an on-site test to investigate the possibility of a new short-process physical method to replace traditional electro-chemical,oil-separation,and two-stage air floating physical chemistry processes,in response to optimizing the treatment effect,thus reducing the cost of treatment and carbon emissions.Following this test,this new short-flow physical method process could improve the efficiency of oil and suspend solid(SS)removal by 15.48%and 58.72%,and providing 78.37%and 75.55%the operating costs and carbon emissions savings,respectively.This system also reduced the production of waste solids,volatile organic compounds,and other three-waste compared with the traditional process.These benefits offer environmental and economic advantages,and this process serves as an efficient strategy to treat wastewater for electric desalination,and can be served as a completely new technological and process option for the treatment of EDW.
基金support of the Project of the Russian Federation represented by the Ministry of Science and Higher Education of the Russian Federation:assistance in the form of grants in accordance with paragraph 4 of article 78.1 of the Budget Code of the Russian Federation(agreement No.075-15-2023-592 on subject No.13.2251.21.0216)CEREMAC-G own research fund and a Support special fi nancier of the Ministry of Higher Education,Scientifi c Research and Innovation(MESRSI)of the Republic of Guinea.
文摘The concentrations of polycyclic aromatic hydrocarbons(PAHs),their sources and toxic equivalent(TEQ)in soil,suspended matter and bottom sediments in the Fatala River Basin ecosystem were obtained for the fi rst time to our knowledge.Determination of 14 PAHs(ΣPAHs)was carried out using high-performance liquid chromatography.TheΣPAH content in soil ranged from 13 to 50,920(Me=820)ng/g.The composition of PAHs(high proportion of low-molecular-weight compounds and values of individual PAHs ratios)refl ected the signifi cant oil pollution of soil.Contaminated soil was localated in the central part of the Fatala River Basin.The median benzo(a)pyrene toxic equivalent of soil at the study site was 1.08(range,0.05 to 53.16)ngTEQ/g,showing generally low soil toxicity.TheΣPAH content in suspended matter was in the range of 33 to 1316(Me=309)ng/L.TheΣPAH content in bottom sediments ranged from 36 to 6943(Me=478)ng/L,corresponding to clean and moderately contaminated sediments.TheΣPAH content in bottom sediments depended on the anthropogenic impact on the Fatala River Basin territory and the bottom sediment features.Bottom sediments and suspended matter had a low toxic equivalent.
文摘According to some main assumptions in the Rouse Formula,it analyzes the applicability of Rouse distribution in the coastal region.Based on the classical Rouse Formula,the linear form of Rouse Formula and the transport characteristics of offshore sediment were used to take lnz/h,lnc_(a),c_(a),u,lnu and z/h as the independent variables.The multiple liner regression method was used to analyze the influence of the independent variables on the vertical distribution of sediment concentration.By using the method of significance test,the factors(ln𝑢)that have less influence on sediment concentration among 6 variables were eliminated.The correlation coefficient between the calculated sediment concentration and the measured sediment concentration indicates that the adopted variables can reflect the characteristics of vertical distribution of concentration of fine sediment near shore under complex dynamic conditions.
基金Project supported by the National Natural Science Foundation of China(Nos.W2433004 and 12472015)the Research Fund of the State Key Laboratory of Mechanics and Control of Mechanical Structures(Nanjing University of Aeronautics and Astronautics)(No.MCMS-I-0122K01).
文摘This paper proposes an attitude control strategy for a flexible satellite equipped with an orthogonal cluster of three-dimensional(3D)magnetically suspended wheels(MSWs).The mathematical model for the satellite incorporating flexible appendages and an orthogonal cluster of magnetically suspended reaction wheel actuators is initially developed.After that,an adaptive attitude controller is designed with a switching surface of variable structure,an adaptive law for estimating inertia matrix uncertainty,and a fuzzy disturbance observer for estimating disturbance torques.Additionally,a Moore-Penrose-based steering law is proposed to derive the tilt angle commands of the orthogonal configuration of the 3D MSW to follow the designed control signal.Finally,numerical simulations are presented to validate the effectiveness of the proposed control strategy.
基金supporting us by providing technical facilities(access to journals)。
文摘This review provides insight into the current research trend in transition metal oxides(TMOs)-based photocatalysis in removing the organic colouring matters from water.For easy understanding,the research progress has been presented in four generations according to the catalyst composition and mode of application,viz:single component TMOs(the firstgeneration),doped TMOs/binary TMOs/doped binary TMOs(the second-generation),inactive/active support-immobilized TMOs(the third-generation),and ternary/quaternary compositions(the fourth-generation).The first two generations represent suspended catalysts,the third generation is supported catalysts,and the fourth generation can be suspended or supported.The review provides an elaborated comparison between suspended and supported catalysts,their general/specific requirements,key factors controlling degradation,and the methodologies for performance evaluation.All the plausible fundamental and advanced dye degradation mechanisms involved in each generation of catalysts were demonstrated.The existing challenges in TMOs-based photocatalysis and how the researchers approach the hitch to resolve it effectively are discussed.Future research trends are also presented.
基金supported by the National Natural Science Foundation of China(Nos.12174444 and 52202195)the Natural Science Foundation of Hunan Province(2020RC3032)。
文摘Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals forces.However,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional semiconductors.Here,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)heterostructures.Electrons in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral range.By eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or hBN.Wefurther demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal equilibrium.Direct cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical excitation.It is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal radiation.The demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulators.
基金financially supported by the National Natural Science Foundation of China(Nos.U22A20580,42130410,and U1906210)the Fundamental Research Funds for the Central Universities(No.201962003).
文摘Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and desorption.We analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year period.Results showed that medium silt(16–32µm)was the main component.As expected,the activity of each radionuclide decreased with an increase of particle size.We examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different sources.Our results indicate that fine SPM(<32µm)was mainly from the erosion of soil along the lower reaches of the Yellow River,while coarse SPM(>32µm)was mainly derived from resuspension of riverbed sediment.During high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream increased.Naturally occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea.
基金The Scientific Research Foundation of the Third Institute of Oceanography,Ministry of Natural Resources under contract Nos TIO2020008 and TIO2019028the Project of Marine Protected Areas Network in China-ASEAN Countries,National Key Research and Development Programe under contract No.2017YFC1405100the National Science Foundation of China under contract No.41976050.
文摘Global carbon cycle has received extensive attention,among which the river-estuary system is one of the important links connecting the carbon cycle between land and ocean.In this paper,the distribution and control factors of particulate organic carbon(POC)were studied by using the data of organic carbon contents and its carbon isotopic composition(δ13C)in the mainstream and estuary of Passur River in the Sundarbans area,combined with the hydrological and biological data measured by CTD.The results show that POC content ranged from 0.263 mg/L to 9.292 mg/L,and the POC content in the river section(averaged 4.129 mg/L)was significantly higher than that in the estuary area(averaged 0.858 mg/L).Two distinct stages of POC transport from land to sea in the Sundarbans area were identified.The first stage occurred in the river section,where POC distribution was mainly controlled by the dynamic process of runoff and the organic carbon was mainly terrestrial source.The second stage occurred during estuarine mixing,where the POC distribution was mainly controlled by the mixing process of seawater and freshwater.The source of POC was predominantly marine and exhibiting vertical differences.The surface and middle layers were primarily influenced by marine sources,while the bottom layer was jointly controlled by terrestrial and marine sources of organic carbon.These findings are of great significance for understanding the carbon cycle in such a large mangrove ecosystem like the Sundarbans mangrove.
基金support of the CONACYTFORDECYT-PRONACES/6364/2020 projectthe funding granted by SIP projects 20181094 and 20196679。
文摘The present study aimed to evaluate multi-element concentrations(Al,As,Ca,Cd,Co,Cr,Cu,Fe,Mg,Mn,Mo,Ni,Pb,Sr)in suspended particulate material(SPM)collected from Ensenada de La Paz(ELP)lagoon,Baja California Sur,Mexico in two different periods(September and May)to comprehend their origin,geochemical behavior,mass transfer and associated ecotoxicological risks.The 24 hr variation coefficient of volumetric SPM levels were found to be 51.7%in September and 40.5%in May,signifying the effects of oceanic waters.The calculated enrichment factor(EF)values for all the studied elements were of higher magnitude because of the high surface area and oxide nature of SPM,and in this study,Mo had the highest EF of 46.77 probably due to its origin from continental weathering.From the ecotoxicological perspective,the integrated toxic risk index revealed low toxic risk to the benthic community.However,the mean-ERM-Quotient calculated using the particulate concentrations of As,Cd,Cr,Cu,Ni,Pb indicated 9%probability of toxicity to biota.The comprehensive geochemical and ecotoxicological assessment of particulate metal concentrations in the ELP lagoon signify low to moderate contamination.
基金Basic Research Funds for Colleges and Universities directly under the Inner Mongolia Autonomous Region:Desert Ecosystem Protection and Restoration Innovation Team(BR 22-13-03).
文摘Wind erosion is a geomorphic process in arid and semi-arid areas and has substantial implications for regional climate and desertification.In the Columbia Plateau of northwestern United States,the emissions from fine particles of loessial soils often contribute to the exceedance of inhalable particulate matter(PM)with an aerodynamic diameter of 10μm or less(PM10)according to the air quality standards.However,little is known about the threshold friction velocity(TFV)for particles of different sizes that comprise these soils.In this study,soil samples of two representative soil types(Warden sandy loam and Ritzville silt loam)collected from the Columbia Plateau were sieved to seven particle size fractions,and an experiment was then conducted to determine the relationship between TFV and particle size fraction.The results revealed that soil particle size significantly affected the initiation of soil movement and TFV;TFV ranged 0.304-0.844 and 0.249-0.739 m/s for different particle size fractions of Ritzville silt loam and Warden sandy loam,respectively.PM10 and total suspended particulates(TSP)emissions from a bed of 63-90μm soil particles were markedly higher for Warden sandy loam than for Ritzville silt loam.Together with the lower TFV of Warden sandy loam,dust emissions from fine particles(<100μm in diameter)of Warden sandy loam thus may be a main contributor to dust in the region's atmosphere,since the PM10 emissions from the soil erosion surfaces and its ensuing suspension within the atmosphere constitute an essential process of soil erosion in the Columbia Plateau.Developing and implementing strategic land management practices on sandy loam soils is therefore necessary to control dust emissions in the Columbia Plateau.
文摘The design of a ship is a process facilitated by different parallel departments.Specialists from various disciplines jointly work on a project,eventually covering the entire process.Though simultaneously,these disciplines are often subject to a hierarchy,either clearly defined or dictated by necessity.Within these branches,despite a growing interest in enhancing the comfort on board ships,noise and vibration design is among the most sacrificed.Compared to hydrodynamic or structural modifications,efforts devoted to improving vibrational comfort are generally slightly impactful and costly.Consequently,these improvements are often relegated to the final stages of the design procedure.The underestimation of noise and vibrational comfort design can generate serious,unexpected issues emerging only in the advanced phases of the ship’s life,and post-construction interventions are often needed.This case is exemplified in the current study,where the crew of the research vessel Mintis,a catamaran-type hull,reported discomfort in the navigation wheelhouse.A measurement campaign was set up to assess the complaints of the operating personnel regarding the high vibrational levels.Subsequent to the measurements,a numerical simulation,specifically comprising a modal analysis,was conducted to investigate the nature of the disturbance and distinguish the underlying mechanism at its origin.This paper meticulously presents and discusses the strategy undertaken to analyze and solve the vibrational problem encountered on board,with particular attention to the criteria and the modeling considerations adopted.
