The tenth BRICS Summit was held in Johannesburg,South Africa in 2018,which attracted attention from the whole world.Especially,it is of great importance to the BRICS nations,for it is the first ten years of BRICS,whic...The tenth BRICS Summit was held in Johannesburg,South Africa in 2018,which attracted attention from the whole world.Especially,it is of great importance to the BRICS nations,for it is the first ten years of BRICS,which marks its growth.Meanwhile,this year the Trump administration imposed more strict policies on protectionism.Particularly,the trade war between China and the United States is so intensive.China,as the core member of BRICS has great clout on BRICS,so the trade war between China and US also arouse a heat discussion among the BRICS nations.During the Summit,CGTN invited experts from the five BRICS nations to discuss related topics.Systemic Functional Linguistics,as one of the most influential branches of Linguistics,was firstly established by M.A.K.Halliday,and it has been greatly developed over the past decades.Interpersonal meaning is one of the three meta-functions,which focuses on how addressers use language to communicate,establish and maintain relationships with addressees,and express their opinions.Mood and modality are two basic resources to the realization of interpersonal meaning.Mood is used to represent the interaction of the language users,while modality reflects the utterers’attitudes and judgments.The paper discusses the three aspects of modality:modal operators,modal adjuncts and metaphors of modality.The paper applies the modality system to the analysis of the transcript of BRICS TALK.The author selects the experts’speeches on the trade war between China and US as the data.The research questions are as followed:(1)the characteristics of the modality resources appeared in their talks;(2)the BRICS nations attitudes and stance on trade war and America’s protectionism.展开更多
Present of wind power is sporadically and cannot be utilized as the only fundamental load of energy sources.This paper proposes a wind-solar hybrid energy storage system(HESS)to ensure a stable supply grid for a longe...Present of wind power is sporadically and cannot be utilized as the only fundamental load of energy sources.This paper proposes a wind-solar hybrid energy storage system(HESS)to ensure a stable supply grid for a longer period.A multi-objective genetic algorithm(MOGA)and state of charge(SOC)region division for the batteries are introduced to solve the objective function and configuration of the system capacity,respectively.MATLAB/Simulink was used for simulation test.The optimization results show that for a 0.5 MW wind power and 0.5 MW photovoltaic system,with a combination of a 300 Ah lithium battery,a 200 Ah lead-acid battery,and a water storage tank,the proposed strategy reduces the system construction cost by approximately 18,000 yuan.Additionally,the cycle count of the electrochemical energy storage systemincreases from4515 to 4660,while the depth of discharge decreases from 55.37%to 53.65%,achieving shallow charging and discharging,thereby extending battery life and reducing grid voltage fluctuations significantly.The proposed strategy is a guide for stabilizing the grid connection of wind and solar power generation,capability allocation,and energy management of energy conservation systems.展开更多
Nowadays,it is extremely urgent for the software engineering education to cultivate the knowledge and ability of database talents in the era of big data.To this end,this paper proposes a talent training teaching modal...Nowadays,it is extremely urgent for the software engineering education to cultivate the knowledge and ability of database talents in the era of big data.To this end,this paper proposes a talent training teaching modality that integrates knowledge,ability,practice,and innovation(KAPI)for Database System Course.The teaching modality contains three parts:top-level design,course learning process,and course assurance and evaluation.The top-level design sorts out the core knowledge of the course and determines a mixed online and offline teaching platform.The course learning process emphasizes the correspondence transformation relationship between core knowledge points and ability enhancement,and the course is practiced in the form of experimental projects to finally enhance students’innovation consciousness and ability.The assurance and evaluation of the course are based on the outcome-based education(OBE)orientation,which realizes the objective evaluation of students’learning process and final performance.The teaching results of the course in the past 2 years show that the KAPI-based teaching modality has achieved better results.Meanwhile,students are satisfied with the evaluation of the modality.The teaching modality in this paper helps to stimulate students’initiatives,and improve their knowledge vision and practical ability,and thus helps to cultivate innovative and high-quality engineering talents required by the emerging engineering education.展开更多
In response to the problem of traditional methods ignoring audio modality tampering, this study aims to explore an effective deep forgery video detection technique that improves detection precision and reliability by ...In response to the problem of traditional methods ignoring audio modality tampering, this study aims to explore an effective deep forgery video detection technique that improves detection precision and reliability by fusing lip images and audio signals. The main method used is lip-audio matching detection technology based on the Siamese neural network, combined with MFCC (Mel Frequency Cepstrum Coefficient) feature extraction of band-pass filters, an improved dual-branch Siamese network structure, and a two-stream network structure design. Firstly, the video stream is preprocessed to extract lip images, and the audio stream is preprocessed to extract MFCC features. Then, these features are processed separately through the two branches of the Siamese network. Finally, the model is trained and optimized through fully connected layers and loss functions. The experimental results show that the testing accuracy of the model in this study on the LRW (Lip Reading in the Wild) dataset reaches 92.3%;the recall rate is 94.3%;the F1 score is 93.3%, significantly better than the results of CNN (Convolutional Neural Networks) and LSTM (Long Short-Term Memory) models. In the validation of multi-resolution image streams, the highest accuracy of dual-resolution image streams reaches 94%. Band-pass filters can effectively improve the signal-to-noise ratio of deep forgery video detection when processing different types of audio signals. The real-time processing performance of the model is also excellent, and it achieves an average score of up to 5 in user research. These data demonstrate that the method proposed in this study can effectively fuse visual and audio information in deep forgery video detection, accurately identify inconsistencies between video and audio, and thus verify the effectiveness of lip-audio modality fusion technology in improving detection performance.展开更多
BACKGROUND Sarcopenia is prevalent among patients with end-stage liver disease(ESLD)and is associated with adverse outcomes both before and after liver transplantation(LT).Accurate assessment of muscle mass is essenti...BACKGROUND Sarcopenia is prevalent among patients with end-stage liver disease(ESLD)and is associated with adverse outcomes both before and after liver transplantation(LT).Accurate assessment of muscle mass is essential for effective risk stratification and optimization of transplant outcomes.AIM To identify imaging modalities used to assess sarcopenia in ESLD patients awaiting LT,and evaluate the clinical utility of each technique in predicting waitlist mortality,length of hospital stay,and post-transplant survival.METHODS A systematic search was conducted in PubMed,MEDLINE,EMBASE,and Scopus for studies published between May 2015 and May 2025.Eligible studies included original research evaluating sarcopenia using imaging techniques in ESLD patients listed for LT.Due to heterogeneity in study design,diagnostic criteria,and outcomes,data were synthesized qualitatively.RESULTS A total of 17 studies met the inclusion criteria,encompassing modalities such as computed tomography(CT),magnetic resonance imaging,dual-energy X-ray absorptiometry,and ultrasound.CT at the third lumbar vertebra level was most frequently used,exhibiting consistent prognostic values for pre-and post-transplant outcomes.However,considerable variability in cutoff values and sarcopenia definitions was observed.Emerging evidence also supports the prognostic relevance of muscle quality indicators,including muscle attenuation and fat infiltration.CONCLUSION CT and magnetic resonance imaging are the most robust imaging methods for sarcopenia diagnosis in patients with ESLD.Standardized diagnostic criteria incorporating muscle quality metrics are essential for improving prognostic accuracy and guiding clinical decision making in LT candidates.Such integration would also support the development of unified frameworks for sarcopenia assessment in transplantation practice.展开更多
This editorial comments on Yang et al’s article that reported a correlation between dynamic contrast-enhanced ultrasound(CEUS)quantitative parameters and Ki67/tumor differentiation.The validation of CEUS as a diagnos...This editorial comments on Yang et al’s article that reported a correlation between dynamic contrast-enhanced ultrasound(CEUS)quantitative parameters and Ki67/tumor differentiation.The validation of CEUS as a diagnostic modality in this study deserves merit.However,it raises interesting points of discussion:(1)Since pancreatic cancer is an overarching term that includes conventional pancreatic ductal adenocarcinoma(PDAC),other subtypes,and neuroendocrine neoplasms(NENs),the inclusion/exclusion criteria require better clarification;(2)Most PDACs are grade 1-2 which contrasts with Yang et al’s study where 46%were grade 3;(3)Ki67 is officially recognized for grading NENs,but not for PDAC;(4)Hotspots are selected for the Ki67 grading of NENs.However,for other tumors(e.g.,breast carcinoma),the average count or hotspots are used;(5)There is no agreement for defining high-grade Ki67 cut-off for non-NENs;reports range from 10%to 50%;and(6)Ki67 reflects cellular proliferation but is not always the most important indicator for biologic aggressiveness.That notwithstanding,since the ratification of Ki67 for prognosis in NENs was based on survival outcomes,the real gold standard should be survival,instead of using Ki67 as a surrogate gold standard.In conclusion,the validation of CEUS parameters for PDAC is a work in progress.CEUS is valuable in assessing PDAC but should be viewed as augmenting other modalities such as computed tomography,magnetic resonance imaging,positron emission tomography and endoscopic ultrasound.展开更多
The cooperative control of ride comfort and handling stability in automobile suspension systems presents a significant challenge in intelligent chassis system design.This complexity arises from the high degrees of fre...The cooperative control of ride comfort and handling stability in automobile suspension systems presents a significant challenge in intelligent chassis system design.This complexity arises from the high degrees of freedom,diverse operating conditions,and inherent trade-offs between performance metrics in full-car suspension systems.In this paper,a novel switching control strategy is proposed to better balance ride comfort and handling stability for a full-car suspension system.The system integrates a ride comfort controller and an anti-rollover controller,guided by a new rollover risk assessment indicator that requires fewer state variables.First,a vehicle suspension simplification model approach is introduced,reducing the fourteen-degree-of-freedom full-car suspension model to three two-degree-of-freedom models:vertical,pitch and roll.Based on these simplified models,vertical,roll,and pitch controllers are designed,simplifying the controller design process for full-car suspension systems.The ride comfort controller is constructed using the modal energy method in conjunction with the simplified model controllers,while the roll controller functions as the anti-rollover controller.The proposed rollover risk assessment indicator serves as the switching criterion between handling stability and ride comfort control.Experimental results demonstrate that the proposed switching control strategy effectively adapts to various road conditions,enabling the semi-active variable damping suspension system to perform multi-modal switching.Compared to a well-tuned passive suspension,vertical,roll,and pitch accelerations are reduced by 14.13%,13.02%and 13.08%,respectively,significantly improving ride comfort.Additionally,the system effectively mitigates rollover risk,achieving reductions in roll angle,roll speed,and roll acceleration by 19.69%,16.40%,and 29.96%,respectively,thereby greatly enhancing vehicle safety.Overall,the proposed switching control strategy achieves a successful balance between ride comfort and handling stability,enhancing overall driving performance.展开更多
The sound field driven by piping systems in enclosures may severely affect living comfort,which is frequently encountered in various engineering applications.Managing this sound field relies heavily on the available p...The sound field driven by piping systems in enclosures may severely affect living comfort,which is frequently encountered in various engineering applications.Managing this sound field relies heavily on the available prediction tools at hand,e.g.,the widely used finite element methods are computationally expensive due to the necessity to discretize entire space,analytical models,based on modal expansion method,may offer substantial advantages in terms of computational cost and efficiency.However,deriving eigenmodes of irregular enclosed spaces may be challenging,which impedes accurate and rapid predictions of the sound field in practical applications.This study presents an analytical framework aimed at rapidly and accurately predicting the interior sound field driven by the piping system vibrations in irregular enclosures.Vibration response of the piping system is obtained using the wave approach,and a line dipole source is idealized as the sound source of the piping system vibration.On the basis of eigenmodes of regular enclosures,the Kirchhoff-Helmholtz integral theorem(modal ex-pansion method for irregular enclosures)is introduced to account for the boundaries of irregular enclosures.This theoretical framework is validated through numerical simulations by finite element method and experiments,demonstrating high accuracy and significant efficiency advantages.The proposed method can be further employed to optimize radiated sound fields by tailoring the impedance of space walls or layout of piping systems.This study provides an efficient tool for predicting radiated sound field in general enclosures driven by vibration of piping systems,paving a new path for indoor acoustical optimization.展开更多
The application of carbon capture systems on ships is technically constrained by limited onboard space and the weight of the conventional absorption tower.The rotating packed bed(RPB)has emerged as a promising alterna...The application of carbon capture systems on ships is technically constrained by limited onboard space and the weight of the conventional absorption tower.The rotating packed bed(RPB)has emerged as a promising alternative due to its small footprint and high mass transfer performance.However,despite its advantages,the structural and vibration stability of RPBs at high rotational speed remains insufficiently studied,and no international design standards currently exist for RPBs.To address this gap,this study performed a comprehensive finite element analysis(FEA)using ANSYS to investigate the structural and dynamic characteristics of an RPB.A three-dimensional model was developed to evaluate the effects of material selection(316 stainless steel,aluminum alloy,titanium alloy),bearing stiffness,and unbalanced mass on deformation,stress,and natural frequencies.In the structural analysis,316 stainless steel exhibited the highest von Mises stress and deformation.However,it was confirmed that all three materials did not exceed their yield strengths at the maximum rotating speed.Modal analysis and Campbell diagrams showed no resonance risk within the rated speed range,and increased bearing stiffness led to higher natural frequencies and improved stability.The findings provide quantitative design guidance for material selection,bearing stiffness optimization,and vibration control in high-rotational-speed RPB systems.This study contributes to establishing a foundational framework for the mechanical reliability and standardization of marine carbon capture units.展开更多
Underwater launch is a transient vibration process under the impact load.The hydrodynamic calculation is an important part of equipment research.In this paper,firstly,combining the theory of the Euler-Bernoulli beam a...Underwater launch is a transient vibration process under the impact load.The hydrodynamic calculation is an important part of equipment research.In this paper,firstly,combining the theory of the Euler-Bernoulli beam and the potential flow,the transfer equation of the Euler-Bernoulli beam considering the hydroelastic effect is derived,which expands the application scope of the transfer matrix.The correctness of the transfer matrix for the beam with hydroelastic behaviors is verified by comparison with the results of the finite element analysis.Then the dynamics model of the underwater launch system is established based on the multibody system transfer matrix method,and the beam with hydroelastic behaviors is employed as the external vehicle.Subsequently,the overall transfer and dynamic equation are derived,resulting in the solution of the wet natural frequency and the dynamic response under the impact load.The comparison with experimental data validates the dynamics model and simulation results and ensures its reliability in practical applications.The dynamic of the system demonstrates that the launching interval and adjacent tube effect will exert an influence on the subsequent emission.This research provides a fast and efficient method for the dynamic calculation of the underwater launch system.展开更多
The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the dam...The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.展开更多
Based on the interpersonal function in Halliday’s systemic functional grammar,"Miranda Warnings",the typical English Police Caution,is analyzed from the aspects of Mood system,Modality system and Appraisal ...Based on the interpersonal function in Halliday’s systemic functional grammar,"Miranda Warnings",the typical English Police Caution,is analyzed from the aspects of Mood system,Modality system and Appraisal system,with the aim of exploring its interpersonal meanings.Results show that:first,the declarative mood and interrogative mood used in the police caution protect the legitimate rights of the interrogated;second,the widely use of Low value modal verbs demonstrates a more humane and democratic legislation principle;and third,the absence of Affect resources and the frequent application of Capacity resources narrow the interpersonal distance between policeman and the interrogated,reflecting the transformation in policeman’s interrogation practices.展开更多
An output-only modal identification method by a combination use of the peak-picking method and the cross spectrum methods are presented. Meanwhile, a novel mode shape optimum method of the deck is proposed. The method...An output-only modal identification method by a combination use of the peak-picking method and the cross spectrum methods are presented. Meanwhile, a novel mode shape optimum method of the deck is proposed. The methods are applied to the operational modal identification system of the Runyang Suspension Bridge, which can be used to obtain the modal parameters of the bridge from out-only data sets collected by its structural health monitoring system （SHMS）. As an example, the vibration response data of the deck, cable and tower recorded during typhoon Matsa excitation are used to illustrate the program application. Some of the modal frequencies observed from deck vibration responses are also found in the vibration responses of the cable and the tower. The results show that some modal shapes of the deck are strongly coupled with the cable and the tower. By comparing the identification results from the operational modal system with those from field measurements, a good agreement between them is achieved, but some modal frequencies identified from the operational modal identification system （OMIS）, such as L1 and L2, obviously decrease compared with those from the field measurements.展开更多
The dynamics model of the transmission system of the internal grinder is established on the bases of Riccati transfer matrix. The dynamic characteristics of the internal grinder are obtained by analyzing the relations...The dynamics model of the transmission system of the internal grinder is established on the bases of Riccati transfer matrix. The dynamic characteristics of the internal grinder are obtained by analyzing the relationship between dynamic modal flexibility and modal flexibility, which is used to find out the dangerous model of the transmission system and its weak areas. Then design parameters of weak areas are modified, the new one from the old structure is put forward, and the dynamic characteristics of new ...展开更多
Adaptive truss structures are a new kind of structures with integrated active members,whose dynamic characteristies can be beneficially modified to meet mission requirements.Active members containing actuating and sen...Adaptive truss structures are a new kind of structures with integrated active members,whose dynamic characteristies can be beneficially modified to meet mission requirements.Active members containing actuating and sensing units are the major components of adaptive truss structures.Modeling of adaptive truss structures is a key step to analyze the structural dynamic characteristics.A new experimental modal analysis approach,in which active members are used as excitatiDn sources for modal test,has been proposed in this paper.The excitation forces generated by the active members, which are different from the excitation forces exerted on structures in the conventional modal test,are internal forces for the truss structures.The relation between internal excitation forces and external forces is revealed such that the traditional identification method can be adopted to obtain modal parameters of adaptive structures.Placement problem of the active member in adaptive truss structures is also discussed in this work. Modal test and analysis are conducted with a planar adaptive truss structure by using piezoelectric active members in order to verify the feasibility and effectiveness of the proposed method.展开更多
Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation fo...Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation for the elastically supported fluid-conveying pipe is transformed into ordinary differential equations using the Galerkin truncation method.The Chebyshev interval approach,integrated with the assumed mode method is then used to investigate the effects of uncertainties of support stiffness,fluid speed,and pipe length on the natural frequencies and mode shapes of the pipe.Additionally,both symmetrical and asymmetrical support stiffnesses are discussed.The accuracy and effectiveness of the Chebyshev interval approach are verified through comparison with the Monte Carlo method.The results reveal that,for the same deviation coefficient,uncertainties in symmetrical support stiffness have a greater impact on the first four natural frequencies than those of the asymmetrical one.There may be significant differences in the sensitivity of natural frequencies and mode shapes of the same order to uncertain parameters.Notably,mode shapes susceptible to uncertain parameters exhibit wider fluctuation intervals near the elastic supports,requiring more attention.展开更多
Microrobotic systems are emerging as transformative technology for minimally invasive medicine,driven by innovations in actuation mechanisms,advanced fabrication paradigms,and multifunctional system integration.This c...Microrobotic systems are emerging as transformative technology for minimally invasive medicine,driven by innovations in actuation mechanisms,advanced fabrication paradigms,and multifunctional system integration.This comprehensive review analyzes the evolution of microrobotic technologies through three critical dimensions:(1)actuation modalities,including magnetic,optical,acoustic,chemical,and biological actuation,with a focus on the synergistic advantages of hybrid actuation strategies in complex internal physiological environments;(2)Fabrication methods cover technolo-gies such as photolithography,microinjection molding,self-assembly,and 3D printing,emphasizing innovative strategies involving multi-technology integration and collaborative manufacturing of bio/non-bio hybrid materials;(3)Internal phys-iological applications involve disease diagnosis,targeted drug delivery,minimally invasive surgery,tissue engineering,and cell manipulation,highlighting the broad prospects of microrobots in precision medicine.Despite remarkable progress,critical challenges remain,including low actuation efficiency,as seen in acoustic systems,limited biocompatibility,exem-plified by the toxicity of hydrogen peroxide in chemical actuation,delayed clinical translation,and other related challenges that must be addressed to advance the field.展开更多
As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises s...As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.展开更多
In the version of the article originally published in the volume 68,issue 12,2025 of Sci China Mater(pages 4413-4422,https://doi.org/10.1007/s40843-025-3667-7),the Chinese name of the co-first author(肖天孝)was incorr...In the version of the article originally published in the volume 68,issue 12,2025 of Sci China Mater(pages 4413-4422,https://doi.org/10.1007/s40843-025-3667-7),the Chinese name of the co-first author(肖天孝)was incorrect.The corrected Chinese name is:肖天笑.展开更多
Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery supp...Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery support structures in electric aircraft,conventional absorbers and isolators are insufficient for effective vibration control.This study simplifies the battery support structure of electric aircraft as an integrated composite beam consisting of three interconnected beams,and investigated its structural dynamics properties and nonlinear vibration control under thermal conditions caused by battery heat.The nonlinear vibration control is performed using the Nitinol steel wire ropes(Ni Ti-ST),with nonlinear damping properties.The natural frequencies of system are determined using the Rayleigh-Ritz technique.Theoretical results are validated through both Finite Element Method(FEM)and hammer tests.Moreover,the dynamic equations are derived using the Lagrange method and discretized via the Galerkin Truncation Method(GTM).The Harmonic Balance Method(HBM)is used to evaluate the vibration responses of the integrated model,with further verification through the Runge-Kutta Method(RKM).The experiments are conducted to corroborate the theoretical analysis.The results show that the system frequency changes in stages with the increase of the stiffness of the integrated composite beam connection.Especially in the case of varying environments,as the temperature increases,the frequency of system will first increase to a certain maximum value and then gradually decrease.Furthermore,the NiTi-ST effectively reduces vibration in the integrated composite beam,particularly under varying temperatures and external excitations.展开更多
文摘The tenth BRICS Summit was held in Johannesburg,South Africa in 2018,which attracted attention from the whole world.Especially,it is of great importance to the BRICS nations,for it is the first ten years of BRICS,which marks its growth.Meanwhile,this year the Trump administration imposed more strict policies on protectionism.Particularly,the trade war between China and the United States is so intensive.China,as the core member of BRICS has great clout on BRICS,so the trade war between China and US also arouse a heat discussion among the BRICS nations.During the Summit,CGTN invited experts from the five BRICS nations to discuss related topics.Systemic Functional Linguistics,as one of the most influential branches of Linguistics,was firstly established by M.A.K.Halliday,and it has been greatly developed over the past decades.Interpersonal meaning is one of the three meta-functions,which focuses on how addressers use language to communicate,establish and maintain relationships with addressees,and express their opinions.Mood and modality are two basic resources to the realization of interpersonal meaning.Mood is used to represent the interaction of the language users,while modality reflects the utterers’attitudes and judgments.The paper discusses the three aspects of modality:modal operators,modal adjuncts and metaphors of modality.The paper applies the modality system to the analysis of the transcript of BRICS TALK.The author selects the experts’speeches on the trade war between China and US as the data.The research questions are as followed:(1)the characteristics of the modality resources appeared in their talks;(2)the BRICS nations attitudes and stance on trade war and America’s protectionism.
基金supported by a Horizontal Project on the Development of a Hybrid Energy Storage Simulation Model for Wind Power Based on an RT-LAB Simulation System(PH2023000190)the Inner Mongolia Natural Science Foundation Project and the Optimization of Exergy Efficiency of a Hybrid Energy Storage System with Crossover Control for Wind Power(2023JQ04).
文摘Present of wind power is sporadically and cannot be utilized as the only fundamental load of energy sources.This paper proposes a wind-solar hybrid energy storage system(HESS)to ensure a stable supply grid for a longer period.A multi-objective genetic algorithm(MOGA)and state of charge(SOC)region division for the batteries are introduced to solve the objective function and configuration of the system capacity,respectively.MATLAB/Simulink was used for simulation test.The optimization results show that for a 0.5 MW wind power and 0.5 MW photovoltaic system,with a combination of a 300 Ah lithium battery,a 200 Ah lead-acid battery,and a water storage tank,the proposed strategy reduces the system construction cost by approximately 18,000 yuan.Additionally,the cycle count of the electrochemical energy storage systemincreases from4515 to 4660,while the depth of discharge decreases from 55.37%to 53.65%,achieving shallow charging and discharging,thereby extending battery life and reducing grid voltage fluctuations significantly.The proposed strategy is a guide for stabilizing the grid connection of wind and solar power generation,capability allocation,and energy management of energy conservation systems.
基金the support from the General Program of the Educational Teaching Reform Research Project of Northwestern Polytechnical University(Grant No.2023JGY35)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515110252)+1 种基金the Double First-class Construction Foundation(Grant No.22GH010616)the Northwestern Polytechnical University of Graduate Student Quality Improvement Program(Grant No.22GZ210101)。
文摘Nowadays,it is extremely urgent for the software engineering education to cultivate the knowledge and ability of database talents in the era of big data.To this end,this paper proposes a talent training teaching modality that integrates knowledge,ability,practice,and innovation(KAPI)for Database System Course.The teaching modality contains three parts:top-level design,course learning process,and course assurance and evaluation.The top-level design sorts out the core knowledge of the course and determines a mixed online and offline teaching platform.The course learning process emphasizes the correspondence transformation relationship between core knowledge points and ability enhancement,and the course is practiced in the form of experimental projects to finally enhance students’innovation consciousness and ability.The assurance and evaluation of the course are based on the outcome-based education(OBE)orientation,which realizes the objective evaluation of students’learning process and final performance.The teaching results of the course in the past 2 years show that the KAPI-based teaching modality has achieved better results.Meanwhile,students are satisfied with the evaluation of the modality.The teaching modality in this paper helps to stimulate students’initiatives,and improve their knowledge vision and practical ability,and thus helps to cultivate innovative and high-quality engineering talents required by the emerging engineering education.
文摘In response to the problem of traditional methods ignoring audio modality tampering, this study aims to explore an effective deep forgery video detection technique that improves detection precision and reliability by fusing lip images and audio signals. The main method used is lip-audio matching detection technology based on the Siamese neural network, combined with MFCC (Mel Frequency Cepstrum Coefficient) feature extraction of band-pass filters, an improved dual-branch Siamese network structure, and a two-stream network structure design. Firstly, the video stream is preprocessed to extract lip images, and the audio stream is preprocessed to extract MFCC features. Then, these features are processed separately through the two branches of the Siamese network. Finally, the model is trained and optimized through fully connected layers and loss functions. The experimental results show that the testing accuracy of the model in this study on the LRW (Lip Reading in the Wild) dataset reaches 92.3%;the recall rate is 94.3%;the F1 score is 93.3%, significantly better than the results of CNN (Convolutional Neural Networks) and LSTM (Long Short-Term Memory) models. In the validation of multi-resolution image streams, the highest accuracy of dual-resolution image streams reaches 94%. Band-pass filters can effectively improve the signal-to-noise ratio of deep forgery video detection when processing different types of audio signals. The real-time processing performance of the model is also excellent, and it achieves an average score of up to 5 in user research. These data demonstrate that the method proposed in this study can effectively fuse visual and audio information in deep forgery video detection, accurately identify inconsistencies between video and audio, and thus verify the effectiveness of lip-audio modality fusion technology in improving detection performance.
文摘BACKGROUND Sarcopenia is prevalent among patients with end-stage liver disease(ESLD)and is associated with adverse outcomes both before and after liver transplantation(LT).Accurate assessment of muscle mass is essential for effective risk stratification and optimization of transplant outcomes.AIM To identify imaging modalities used to assess sarcopenia in ESLD patients awaiting LT,and evaluate the clinical utility of each technique in predicting waitlist mortality,length of hospital stay,and post-transplant survival.METHODS A systematic search was conducted in PubMed,MEDLINE,EMBASE,and Scopus for studies published between May 2015 and May 2025.Eligible studies included original research evaluating sarcopenia using imaging techniques in ESLD patients listed for LT.Due to heterogeneity in study design,diagnostic criteria,and outcomes,data were synthesized qualitatively.RESULTS A total of 17 studies met the inclusion criteria,encompassing modalities such as computed tomography(CT),magnetic resonance imaging,dual-energy X-ray absorptiometry,and ultrasound.CT at the third lumbar vertebra level was most frequently used,exhibiting consistent prognostic values for pre-and post-transplant outcomes.However,considerable variability in cutoff values and sarcopenia definitions was observed.Emerging evidence also supports the prognostic relevance of muscle quality indicators,including muscle attenuation and fat infiltration.CONCLUSION CT and magnetic resonance imaging are the most robust imaging methods for sarcopenia diagnosis in patients with ESLD.Standardized diagnostic criteria incorporating muscle quality metrics are essential for improving prognostic accuracy and guiding clinical decision making in LT candidates.Such integration would also support the development of unified frameworks for sarcopenia assessment in transplantation practice.
文摘This editorial comments on Yang et al’s article that reported a correlation between dynamic contrast-enhanced ultrasound(CEUS)quantitative parameters and Ki67/tumor differentiation.The validation of CEUS as a diagnostic modality in this study deserves merit.However,it raises interesting points of discussion:(1)Since pancreatic cancer is an overarching term that includes conventional pancreatic ductal adenocarcinoma(PDAC),other subtypes,and neuroendocrine neoplasms(NENs),the inclusion/exclusion criteria require better clarification;(2)Most PDACs are grade 1-2 which contrasts with Yang et al’s study where 46%were grade 3;(3)Ki67 is officially recognized for grading NENs,but not for PDAC;(4)Hotspots are selected for the Ki67 grading of NENs.However,for other tumors(e.g.,breast carcinoma),the average count or hotspots are used;(5)There is no agreement for defining high-grade Ki67 cut-off for non-NENs;reports range from 10%to 50%;and(6)Ki67 reflects cellular proliferation but is not always the most important indicator for biologic aggressiveness.That notwithstanding,since the ratification of Ki67 for prognosis in NENs was based on survival outcomes,the real gold standard should be survival,instead of using Ki67 as a surrogate gold standard.In conclusion,the validation of CEUS parameters for PDAC is a work in progress.CEUS is valuable in assessing PDAC but should be viewed as augmenting other modalities such as computed tomography,magnetic resonance imaging,positron emission tomography and endoscopic ultrasound.
基金Supported by the Australian Research Council’s Discovery Project(Grant No.DP200100149)Taishan Scholars Program of Shandong Province(Grant No.tsqn202211062)Chinses Scholarship Council(Grant No.202006690005).
文摘The cooperative control of ride comfort and handling stability in automobile suspension systems presents a significant challenge in intelligent chassis system design.This complexity arises from the high degrees of freedom,diverse operating conditions,and inherent trade-offs between performance metrics in full-car suspension systems.In this paper,a novel switching control strategy is proposed to better balance ride comfort and handling stability for a full-car suspension system.The system integrates a ride comfort controller and an anti-rollover controller,guided by a new rollover risk assessment indicator that requires fewer state variables.First,a vehicle suspension simplification model approach is introduced,reducing the fourteen-degree-of-freedom full-car suspension model to three two-degree-of-freedom models:vertical,pitch and roll.Based on these simplified models,vertical,roll,and pitch controllers are designed,simplifying the controller design process for full-car suspension systems.The ride comfort controller is constructed using the modal energy method in conjunction with the simplified model controllers,while the roll controller functions as the anti-rollover controller.The proposed rollover risk assessment indicator serves as the switching criterion between handling stability and ride comfort control.Experimental results demonstrate that the proposed switching control strategy effectively adapts to various road conditions,enabling the semi-active variable damping suspension system to perform multi-modal switching.Compared to a well-tuned passive suspension,vertical,roll,and pitch accelerations are reduced by 14.13%,13.02%and 13.08%,respectively,significantly improving ride comfort.Additionally,the system effectively mitigates rollover risk,achieving reductions in roll angle,roll speed,and roll acceleration by 19.69%,16.40%,and 29.96%,respectively,thereby greatly enhancing vehicle safety.Overall,the proposed switching control strategy achieves a successful balance between ride comfort and handling stability,enhancing overall driving performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.11632003,11972083,11991030,12372088,and U22B2078)Beijing Institute of Technology Research Fund Program for Young Scholars(Grant No.XSQD-202101010).
文摘The sound field driven by piping systems in enclosures may severely affect living comfort,which is frequently encountered in various engineering applications.Managing this sound field relies heavily on the available prediction tools at hand,e.g.,the widely used finite element methods are computationally expensive due to the necessity to discretize entire space,analytical models,based on modal expansion method,may offer substantial advantages in terms of computational cost and efficiency.However,deriving eigenmodes of irregular enclosed spaces may be challenging,which impedes accurate and rapid predictions of the sound field in practical applications.This study presents an analytical framework aimed at rapidly and accurately predicting the interior sound field driven by the piping system vibrations in irregular enclosures.Vibration response of the piping system is obtained using the wave approach,and a line dipole source is idealized as the sound source of the piping system vibration.On the basis of eigenmodes of regular enclosures,the Kirchhoff-Helmholtz integral theorem(modal ex-pansion method for irregular enclosures)is introduced to account for the boundaries of irregular enclosures.This theoretical framework is validated through numerical simulations by finite element method and experiments,demonstrating high accuracy and significant efficiency advantages.The proposed method can be further employed to optimize radiated sound fields by tailoring the impedance of space walls or layout of piping systems.This study provides an efficient tool for predicting radiated sound field in general enclosures driven by vibration of piping systems,paving a new path for indoor acoustical optimization.
基金support of the Korea Institute of Industrial Technology and Promotion,with the financial resources of the government(Ministry of Trade,Industry,and Energy)in 2024.(RS-2024-00424595,project to train high-quality researchers for the next generation of marine mobility industry innovation).
文摘The application of carbon capture systems on ships is technically constrained by limited onboard space and the weight of the conventional absorption tower.The rotating packed bed(RPB)has emerged as a promising alternative due to its small footprint and high mass transfer performance.However,despite its advantages,the structural and vibration stability of RPBs at high rotational speed remains insufficiently studied,and no international design standards currently exist for RPBs.To address this gap,this study performed a comprehensive finite element analysis(FEA)using ANSYS to investigate the structural and dynamic characteristics of an RPB.A three-dimensional model was developed to evaluate the effects of material selection(316 stainless steel,aluminum alloy,titanium alloy),bearing stiffness,and unbalanced mass on deformation,stress,and natural frequencies.In the structural analysis,316 stainless steel exhibited the highest von Mises stress and deformation.However,it was confirmed that all three materials did not exceed their yield strengths at the maximum rotating speed.Modal analysis and Campbell diagrams showed no resonance risk within the rated speed range,and increased bearing stiffness led to higher natural frequencies and improved stability.The findings provide quantitative design guidance for material selection,bearing stiffness optimization,and vibration control in high-rotational-speed RPB systems.This study contributes to establishing a foundational framework for the mechanical reliability and standardization of marine carbon capture units.
基金supported by the National Natural Science Foundation of China(Grant No.92266201).
文摘Underwater launch is a transient vibration process under the impact load.The hydrodynamic calculation is an important part of equipment research.In this paper,firstly,combining the theory of the Euler-Bernoulli beam and the potential flow,the transfer equation of the Euler-Bernoulli beam considering the hydroelastic effect is derived,which expands the application scope of the transfer matrix.The correctness of the transfer matrix for the beam with hydroelastic behaviors is verified by comparison with the results of the finite element analysis.Then the dynamics model of the underwater launch system is established based on the multibody system transfer matrix method,and the beam with hydroelastic behaviors is employed as the external vehicle.Subsequently,the overall transfer and dynamic equation are derived,resulting in the solution of the wet natural frequency and the dynamic response under the impact load.The comparison with experimental data validates the dynamics model and simulation results and ensures its reliability in practical applications.The dynamic of the system demonstrates that the launching interval and adjacent tube effect will exert an influence on the subsequent emission.This research provides a fast and efficient method for the dynamic calculation of the underwater launch system.
基金Project supported by the National Natural Science Foundation of China (No. 12272323)。
文摘The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.
文摘Based on the interpersonal function in Halliday’s systemic functional grammar,"Miranda Warnings",the typical English Police Caution,is analyzed from the aspects of Mood system,Modality system and Appraisal system,with the aim of exploring its interpersonal meanings.Results show that:first,the declarative mood and interrogative mood used in the police caution protect the legitimate rights of the interrogated;second,the widely use of Low value modal verbs demonstrates a more humane and democratic legislation principle;and third,the absence of Affect resources and the frequent application of Capacity resources narrow the interpersonal distance between policeman and the interrogated,reflecting the transformation in policeman’s interrogation practices.
基金The National High Technology Research and Development Program of China(863Program)(No.2006AA04Z416)
文摘An output-only modal identification method by a combination use of the peak-picking method and the cross spectrum methods are presented. Meanwhile, a novel mode shape optimum method of the deck is proposed. The methods are applied to the operational modal identification system of the Runyang Suspension Bridge, which can be used to obtain the modal parameters of the bridge from out-only data sets collected by its structural health monitoring system （SHMS）. As an example, the vibration response data of the deck, cable and tower recorded during typhoon Matsa excitation are used to illustrate the program application. Some of the modal frequencies observed from deck vibration responses are also found in the vibration responses of the cable and the tower. The results show that some modal shapes of the deck are strongly coupled with the cable and the tower. By comparing the identification results from the operational modal system with those from field measurements, a good agreement between them is achieved, but some modal frequencies identified from the operational modal identification system （OMIS）, such as L1 and L2, obviously decrease compared with those from the field measurements.
文摘The dynamics model of the transmission system of the internal grinder is established on the bases of Riccati transfer matrix. The dynamic characteristics of the internal grinder are obtained by analyzing the relationship between dynamic modal flexibility and modal flexibility, which is used to find out the dangerous model of the transmission system and its weak areas. Then design parameters of weak areas are modified, the new one from the old structure is put forward, and the dynamic characteristics of new ...
文摘Adaptive truss structures are a new kind of structures with integrated active members,whose dynamic characteristies can be beneficially modified to meet mission requirements.Active members containing actuating and sensing units are the major components of adaptive truss structures.Modeling of adaptive truss structures is a key step to analyze the structural dynamic characteristics.A new experimental modal analysis approach,in which active members are used as excitatiDn sources for modal test,has been proposed in this paper.The excitation forces generated by the active members, which are different from the excitation forces exerted on structures in the conventional modal test,are internal forces for the truss structures.The relation between internal excitation forces and external forces is revealed such that the traditional identification method can be adopted to obtain modal parameters of adaptive structures.Placement problem of the active member in adaptive truss structures is also discussed in this work. Modal test and analysis are conducted with a planar adaptive truss structure by using piezoelectric active members in order to verify the feasibility and effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272211,12072181,and 12121002).
文摘Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation for the elastically supported fluid-conveying pipe is transformed into ordinary differential equations using the Galerkin truncation method.The Chebyshev interval approach,integrated with the assumed mode method is then used to investigate the effects of uncertainties of support stiffness,fluid speed,and pipe length on the natural frequencies and mode shapes of the pipe.Additionally,both symmetrical and asymmetrical support stiffnesses are discussed.The accuracy and effectiveness of the Chebyshev interval approach are verified through comparison with the Monte Carlo method.The results reveal that,for the same deviation coefficient,uncertainties in symmetrical support stiffness have a greater impact on the first four natural frequencies than those of the asymmetrical one.There may be significant differences in the sensitivity of natural frequencies and mode shapes of the same order to uncertain parameters.Notably,mode shapes susceptible to uncertain parameters exhibit wider fluctuation intervals near the elastic supports,requiring more attention.
基金National Natural Science Foundation of China(Grant No.61903157)the Foundation of State Key Laboratory of Robotics(Grand No.2024-O08).
文摘Microrobotic systems are emerging as transformative technology for minimally invasive medicine,driven by innovations in actuation mechanisms,advanced fabrication paradigms,and multifunctional system integration.This comprehensive review analyzes the evolution of microrobotic technologies through three critical dimensions:(1)actuation modalities,including magnetic,optical,acoustic,chemical,and biological actuation,with a focus on the synergistic advantages of hybrid actuation strategies in complex internal physiological environments;(2)Fabrication methods cover technolo-gies such as photolithography,microinjection molding,self-assembly,and 3D printing,emphasizing innovative strategies involving multi-technology integration and collaborative manufacturing of bio/non-bio hybrid materials;(3)Internal phys-iological applications involve disease diagnosis,targeted drug delivery,minimally invasive surgery,tissue engineering,and cell manipulation,highlighting the broad prospects of microrobots in precision medicine.Despite remarkable progress,critical challenges remain,including low actuation efficiency,as seen in acoustic systems,limited biocompatibility,exem-plified by the toxicity of hydrogen peroxide in chemical actuation,delayed clinical translation,and other related challenges that must be addressed to advance the field.
基金supported by the National Natural Science Foundation of China(No.12372233)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.25GH01020005)the“111 Project”of China(No.B17037)。
文摘As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.
文摘In the version of the article originally published in the volume 68,issue 12,2025 of Sci China Mater(pages 4413-4422,https://doi.org/10.1007/s40843-025-3667-7),the Chinese name of the co-first author(肖天孝)was incorrect.The corrected Chinese name is:肖天笑.
基金supported by the National Natural Science Foundation of China(No.12272240)the Liaoning Revitalization Talents Program,China(No.XLYC2203197)。
文摘Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery support structures in electric aircraft,conventional absorbers and isolators are insufficient for effective vibration control.This study simplifies the battery support structure of electric aircraft as an integrated composite beam consisting of three interconnected beams,and investigated its structural dynamics properties and nonlinear vibration control under thermal conditions caused by battery heat.The nonlinear vibration control is performed using the Nitinol steel wire ropes(Ni Ti-ST),with nonlinear damping properties.The natural frequencies of system are determined using the Rayleigh-Ritz technique.Theoretical results are validated through both Finite Element Method(FEM)and hammer tests.Moreover,the dynamic equations are derived using the Lagrange method and discretized via the Galerkin Truncation Method(GTM).The Harmonic Balance Method(HBM)is used to evaluate the vibration responses of the integrated model,with further verification through the Runge-Kutta Method(RKM).The experiments are conducted to corroborate the theoretical analysis.The results show that the system frequency changes in stages with the increase of the stiffness of the integrated composite beam connection.Especially in the case of varying environments,as the temperature increases,the frequency of system will first increase to a certain maximum value and then gradually decrease.Furthermore,the NiTi-ST effectively reduces vibration in the integrated composite beam,particularly under varying temperatures and external excitations.
