Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters accordi...Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.展开更多
Objective Traditional Chinese medicine(TCM)incorporates traditional diagnostic methods and several major treatment modalities including Chinese herbal medicine,Chinese patent medicine,and non-pharmacological methods s...Objective Traditional Chinese medicine(TCM)incorporates traditional diagnostic methods and several major treatment modalities including Chinese herbal medicine,Chinese patent medicine,and non-pharmacological methods such as acupuncture and tuina.Even though TCM is used daily by more than 70,000 healthcare facilities and over 700,000 clinical practitioners in China,there is a poor understanding of the extent to which TCM diagnostic methods are used,how different treatment modalities are deployed in general,and what major factors may affect the integration of TCM and Western medicine.This study aimed to fill this void in the literature.Methods In the 2021 National Healthcare Improvement Evaluation Survey,we included three questions gauging the perception and practices of TCM amongst physicians working in TCM-related facilities,investigating the frequency of their deployment of TCM diagnostic methods,and predominant TCM treatment methods.Our empirical analysis included descriptive statistics,intergroup chi-square analysis,and binary logistic regression to examine the association between different types of facilities and individual characteristics and TCM utilization patterns.Results A total of 7618 clinical physicians comprised our study sample.Among them,84.27%have integrated TCM and Western medicine in their clinical practice,and 80.77%of TCM practitioners used the 4 diagnostic methods as a tool in their clinical practice.Chinese herbal medicine was the most widely utilized modality by Chinese TCM physicians(used by 88.49%of respondents),compared with the Chinese patent medicine and non-pharmacological TCM methods,which were used by 73.14%,and 69.39%,respectively.Herbal tea as an out-of-pocket health-maintenance intervention is also a notable practice,recommended by 29.43%of physicians.Significant variations exist across certain institutions,departments,and individual practitioners.Conclusion Given that most of the surveyed physicians integrated TCM with Western medicine in their clinical practices,the practice of“pure TCM”appears to be obsolete in China’s tertiary healthcare institutions.Notably,remarkable variation exists in the use of different TCM modalities across institutions and among individuals,which might be related to and thus limited by the practitioners’experience.Future research focusing on the efficacy and safety of TCM interventions for specific diseases,the development of standardized clinical guidelines,and the enhancement of TCM education and training are called for to optimize TCM-Western medicine integration.展开更多
In modal logic,topological semantics is an intuitive and natural special case of neighbourhood semantics.This paper stems from the observation that the satisfaction relation of topological semantics applies to subset ...In modal logic,topological semantics is an intuitive and natural special case of neighbourhood semantics.This paper stems from the observation that the satisfaction relation of topological semantics applies to subset spaces which are more general than topological spaces.The minimal modal logic which is strongly sound and complete with respect to the class of subset spaces is found.Soundness and completeness results of some famous modal logics(e.g.S4,S5 and Tr)with respect to various important classes of subset spaces(eg intersection structures and complete fields of sets)are also proved.In the meantime,some known results,e.g.the soundness and completeness of Tr with respect to the class of discrete topological spaces,are proved directly using some modifications of the method of canonical mode1,without a detour via neighbourhood semantics or relational semantics.展开更多
This study examined gender differences in modal choice among residents of coastal communities of Yenagoa metropolis in Bayelsa State, Nigeria. The Four-Step model of transportation planning and modal choice provided t...This study examined gender differences in modal choice among residents of coastal communities of Yenagoa metropolis in Bayelsa State, Nigeria. The Four-Step model of transportation planning and modal choice provided the theoretical basis for this study. A survey research design involving a stratified sampling technique was adopted. The descriptives on transport modes, amount and time spent revealed that 10 (76.9%) males and 3 (23.1%) females preferred bicycle as means of transportation, 7 (58.3%) males and 5 (41.7%) females preferred motorcycle, while a significant proportion 90 (53.9%) males and 77 (46.1%) females preferred tricycle, 80 (63.0%) males and 47 (37.0%) females preferred cars/taxis, and 12 (46.2%) males and 14 (53.8%) females preferred mass transit bus. However, 14 (46.7%) males and 16 (53.3%) females in marshy terrain and coastal locations preferred canoes and boats. The result of the logistic regression model revealed that gender modal preference is more likely to be influenced by mode of transportation with a beta weight of 1.140, safety considerations 1.139, ownership of transport 1.135 and distance to place of work 1.073. Hence, this study recommends that a combination of these factors should be incorporated into transport planning to achieve effective transport planning and sustainable development in the Yenagoa metropolis.展开更多
Normal mode extraction has attracted extensive attention over the past few decades due to its practical value in enhancing the performance of underwater acoustic signal processing.Singular value decomposition(SVD)is a...Normal mode extraction has attracted extensive attention over the past few decades due to its practical value in enhancing the performance of underwater acoustic signal processing.Singular value decomposition(SVD)is an effective method to extract modal depth functions using vertical line arrays(VLA),particularly in scenarios when no prior environment information is available.However,the SVD method requires rigorous orthogonality conditions,and its performance severely degenerates in the presence of mode degeneracy.Consequently,the SVD approach is often not feasible in practical scenarios.This paper proposes a full rank decomposition(FRD)method to address these issues.Compared to the SVD method,the FRD method has three distinct advantages:1)the conditions that the FRD method requires are much easier to be fulfilled in practical scenarios;2)both modal depth functions and wavenumbers can be simultaneously extracted via the FRD method;3)the FRD method is not affected by the phenomenon of mode degeneracy.Numerical simulations are conducted in two types of waveguides to verify the FRD method.The impacts of environment configurations and noise levels on the precision of the extracted modal depth functions and wavenumbers are also investigated through simulation.展开更多
Uneven lithium deposition leading to lithium dendrite growth severely hampers the application of lithium-metal batteries.Modifying the collector with lithiophilic materials helps improve lithium deposition.For lithoph...Uneven lithium deposition leading to lithium dendrite growth severely hampers the application of lithium-metal batteries.Modifying the collector with lithiophilic materials helps improve lithium deposition.For lithophilic materials to modify the collector,the choice of cut-off voltage is very important.While excessively high cut-off voltages may compromise the stability of the modified layer and consequently disrupt ordered lithium deposition,conventional approaches typically employ lower cut-off voltages(particularly 0.1 V)to maintain modification layer stability.However,the 0.1 V cut-off voltage results in incomplete lithium stripping from the lithiophilic material surface.This phenomenon significantly diminishes the lithiophilic properties of the modified layer and consequently leads to substantial nucleation overpotential.Here,we propose to use a moderate cut-voltage stimulation effect to slow down the interfacial shielding effect of residual lithium metal on lithiophilic materials.By optimizing the cut-off voltage for the Cu@Sb_(2)S_(3)collector,the stability of the modified layer can be preserved while enabling the complete stripping of lithium metal from the surface of the lithophilic material.The asymmetric cell received the highest Coulombic efficiency(CE)when the lithium stripping cut-off voltage was set at 0.5 V relative to 0.1 and 2.0 V.At a current density of 1 mA cm^(-2)and a deposition capacity of1 m A h cm^(-2),the CE remained 98.6% at a cut-off voltage of 0.5 V after 140 cycles in an ether electrolyte without lithium nitrate.展开更多
The soil-bentonite(SB)cut-off wall has been widely considered a vertical barrier to effectively control the migration of pollutants in contaminated sites.Recently,active porous materials have been used as a promising ...The soil-bentonite(SB)cut-off wall has been widely considered a vertical barrier to effectively control the migration of pollutants in contaminated sites.Recently,active porous materials have been used as a promising candidate amendment for mitigating chemical degradation and improving the retardation capacity of the SB cut-off wall.In this study,the silty clay from a typical Cr(VI)contaminated site was selected as the body material of the SB cut-off wall,and zeolite and active carbon were used as the modifiers of the silty clay-bentonite backfills,respectively.The impact of the two modifiers on the engineering properties of the backfills was investigated through a series of slump tests,consolidation tests,hydraulic conductivity tests,and microstructure tests.The experimental results demonstrated that the slump curves closely exhibited a linear relationship between standard slump and moisture content.Meanwhile,bentonite could improve the optimum moisture content of the backfills,while the addition of the two modifiers yielded the opposite outcome.As the bentonite content increased,the compression index of the backfills significantly increased,while the hydraulic conductivity decreased.At a given bentonite content of 5%,the addition of zeolite or active carbon resulted in a reduction in the compression index and initial void ratio,while exhibiting minimal impact on the hydraulic conductivity.Scanning electron microscope(SEM)observations indicated that the silty clay-bentonite backfills became increasingly loose with increasing bentonite content,owing to the filling and expansion of dispersed bentonite layers.The amendment of zeolite or active carbon was able to decrease the backfill volume by promoting the agglomeration of layered bentonite.The findings of this study will be useful for the optimal selection of backfill materials and the performance evaluation of the cut-off wall.展开更多
In the present paper,we give a systematic study of the discrete correspondence the-ory and topological correspondence theory of modal meet-implication logic and moda1 meet-semilattice logic,in the semantics provided i...In the present paper,we give a systematic study of the discrete correspondence the-ory and topological correspondence theory of modal meet-implication logic and moda1 meet-semilattice logic,in the semantics provided in[21].The special features of the present paper include the following three points:the first one is that the semantic structure used is based on a semilattice rather than an ordinary partial order,the second one is that the propositional vari-ables are interpreted as filters rather than upsets,and the nominals,which are the“first-order counterparts of propositional variables,are interpreted as principal filters rather than principal upsets;the third one is that in topological correspondence theory,the collection of admissi-ble valuations is not closed under taking disjunction,which makes the proof of the topological Ackermann 1emma different from existing settings.展开更多
Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extra...Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extracellular matrix present in the skin,has become a mainstream method for skin rejuvenation through injections.However,the rapid degradation of pure hyaluronic acid,combined with insufficient maintenance duration and often limited therapeutic effects,presents significant challenges for injectable treatments.Additionally,low patient compliance due to discomfort from needles penetrating the dermal layer further complicates its use.In this review,we summarize and compare existing interventions for skin aging,focusing on strategies to prolong the degradation cycle of hyaluronic acid,including variations in cross-linking modalities and injection techniques.We conclude that the injection of cross-linked modified hyaluronic acid via microneedles represents a promising approach to extend the degradation cycle,offering valuable insights for current therapeutic strategies.展开更多
In recent years,scholars around the world have shown increasing interest in elastic support structures,leading to significant progress in dynamic modeling techniques for pipeline systems.Although multiple analytical a...In recent years,scholars around the world have shown increasing interest in elastic support structures,leading to significant progress in dynamic modeling techniques for pipeline systems.Although multiple analytical approaches exist,engineers increasingly prioritize computationally efficient,precise low-order models for practical implementation.In order to address this need,this study develops an innovative nonlinear dynamic formulation for pipelines accounting for both foundation and boundary nonlinearities.The proposed solution methodology initiates with global mode extraction using the global mode technique,followed by a detailed implementation procedure.Model validation is conducted through a cantilever pipeline case study featuring nonlinear support conditions,where strong agreement between the proposed model's predictions and finiteelement benchmark solutions demonstrates its reliability.Subsequently,a comprehensive parametric study investigates the combined effects of foundation stiffness,boundary constraints,excitation intensity,and nonlinear interaction terms on the vibrational response of the cantilever pipe.This systematic approach yields critical insights for practical engineering designs and applications.展开更多
Because of actual requirement,shield machine always excavates with an inclined angle in longitudinal direction.Since many previous studies mainly focus on the face stability of the horizontal shield tunnel,the effects...Because of actual requirement,shield machine always excavates with an inclined angle in longitudinal direction.Since many previous studies mainly focus on the face stability of the horizontal shield tunnel,the effects of tensile strength cut-off and pore water pressure on the face stability of the longitudinally inclined shield tunnel are not well investigated.A failure mechanism of a longitudinally inclined shield tunnel face is constructed based on the spatial discretization technique and the tensile strength cut-off criterion is introduced to modify the constructed failure mechanism.The pore water pressure is introduced as an external force into the equation of virtual work and the objective function of the chamber pressure of the shield machine is obtained.Moreover,the critical chamber pressure of the longitudinally inclined shield tunnel is computed by optimal calculation.Parametric analysis indicates that both tensile strength cut-off and pore water pressure have a significant impact on the chamber pressure and the range of the collapse block.Finally,the theoretical results are compared with the numerical results calculated by FLAC3D software which proves that the proposed approach is effective.展开更多
In this paper,the sentiment classification method of multimodal adversarial autoencoder is studied.This paper includes the introduction of the multimodal adversarial autoencoder emotion classification method and the e...In this paper,the sentiment classification method of multimodal adversarial autoencoder is studied.This paper includes the introduction of the multimodal adversarial autoencoder emotion classification method and the experiment of the emotion classification method based on the encoder.The experimental analysis shows that the encoder has higher precision than other encoders in emotion classification.It is hoped that this analysis can provide some reference for the emotion classification under the current intelligent algorithm mode.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
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
Rotor blade is one of the most significant components of helicopters. But due to its highspeed rotation characteristics, it is difficult to collect the vibration signals during the flight stage.Moreover, sensors are h...Rotor blade is one of the most significant components of helicopters. But due to its highspeed rotation characteristics, it is difficult to collect the vibration signals during the flight stage.Moreover, sensors are highly susceptible to damage resulting in the failure of the measurement.In order to make signal predictions for the damaged sensors, an operational modal analysis(OMA) together with the virtual sensing(VS) technology is proposed in this paper. This paper discusses two situations, i.e., mode shapes measured by all sensors(both normal and damaged) can be obtained using OMA, and mode shapes measured by some sensors(only including normal) can be obtained using OMA. For the second situation, it is necessary to use finite element(FE) analysis to supplement the missing mode shapes of damaged sensor. In order to improve the correlation between the FE model and the real structure, the FE mode shapes are corrected using the local correspondence(LC) principle and mode shapes measured by some sensors(only including normal).Then, based on the VS technology, the vibration signals of the damaged sensors during the flight stage can be accurately predicted using the identified mode shapes(obtained based on OMA and FE analysis) and the normal sensors signals. Given the high degrees of freedom(DOFs) in the FE mode shapes, this approach can also be used to predict vibration data at locations without sensors. The effectiveness and robustness of the proposed method is verified through finite element simulation, experiment as well as the actual flight test. The present work can be further used in the fault diagnosis and damage identification for rotor blade of helicopters.展开更多
This study investigates cavitating swirling flow in a diffuser,i.e.,a simplified model of a Francis turbine draft tube,using proper orthogonal decomposition(POD)and dynamic mode decomposition(DMD)applied to velocity a...This study investigates cavitating swirling flow in a diffuser,i.e.,a simplified model of a Francis turbine draft tube,using proper orthogonal decomposition(POD)and dynamic mode decomposition(DMD)applied to velocity and pressure field data.The interaction between vortex rope precession and cavitation surge under varying swirl and cavitation numbers is analyzed.The modal analysis results depicted the coherent structures correlated to the vortex rope precession near the diffuser inlet and the diffuser outlet,and cavitation surge in the diffuser.The POD analysis accurately revealed the flow features in the diffuser:The conical structure represents the flow diffusion with vortex rope precession and the reverse core indicates the backflow in the diffuser for the averaged flow,and the double helical structure near the diffuser inlet for the representative flow oscillation.The typical coherent structures obtained by the DMD for the cavitating swirling flow in the diffuser are the double helical structure concentrated near the diffuser inlet.The double helical structure also appears near the diffuser outlet where the breakdown of vortex rope occurs and the flow oscillation slows down.Once cavitation occurs,the mode induced by cavitation surge and its corresponding coherent structure may change according to the operating condition.The flow oscillation can be changed from the double helical mode to the axial oscillation caused by cavitation surge named breathing mode if cavitation surge becomes strong enough at a small cavitation number or large swirl number.展开更多
The lack of soft magnetic composites with high power density in MHz frequency range has become an obstacle in the efficient operation of the electrical and electronic equipments.Here,a promising method to increase the...The lack of soft magnetic composites with high power density in MHz frequency range has become an obstacle in the efficient operation of the electrical and electronic equipments.Here,a promising method to increase the cut-off frequency of iron-based soft magnetic composites to hundreds of MHz is reported.The cut-off frequency is increased from 10 MHz to 1 GHz by modulating the height of the ring,the distribution of particles,and the particle size.The mechanism of cut-off frequency and permeability is the coherent rotation of domain modulated by inhomogeneous field due to the eddy current effect.An empirical formula for the cut-off frequency in a magnetic ring composed of iron-based particles is established from experimental data.This work provides an effective approach to fabricate soft magnetic composites with a cut-off frequency in hundreds of MHz.展开更多
基金supported by the Innovation Foundation of Provincial Education Department of Gansu(2024B-005)the Gansu Province National Science Foundation(22YF7GA182)the Fundamental Research Funds for the Central Universities(No.lzujbky2022-kb01)。
文摘Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.
基金The Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences——A Strategic Study on Healthy China Development and Health System Reform(2021-I2M-1-046).
文摘Objective Traditional Chinese medicine(TCM)incorporates traditional diagnostic methods and several major treatment modalities including Chinese herbal medicine,Chinese patent medicine,and non-pharmacological methods such as acupuncture and tuina.Even though TCM is used daily by more than 70,000 healthcare facilities and over 700,000 clinical practitioners in China,there is a poor understanding of the extent to which TCM diagnostic methods are used,how different treatment modalities are deployed in general,and what major factors may affect the integration of TCM and Western medicine.This study aimed to fill this void in the literature.Methods In the 2021 National Healthcare Improvement Evaluation Survey,we included three questions gauging the perception and practices of TCM amongst physicians working in TCM-related facilities,investigating the frequency of their deployment of TCM diagnostic methods,and predominant TCM treatment methods.Our empirical analysis included descriptive statistics,intergroup chi-square analysis,and binary logistic regression to examine the association between different types of facilities and individual characteristics and TCM utilization patterns.Results A total of 7618 clinical physicians comprised our study sample.Among them,84.27%have integrated TCM and Western medicine in their clinical practice,and 80.77%of TCM practitioners used the 4 diagnostic methods as a tool in their clinical practice.Chinese herbal medicine was the most widely utilized modality by Chinese TCM physicians(used by 88.49%of respondents),compared with the Chinese patent medicine and non-pharmacological TCM methods,which were used by 73.14%,and 69.39%,respectively.Herbal tea as an out-of-pocket health-maintenance intervention is also a notable practice,recommended by 29.43%of physicians.Significant variations exist across certain institutions,departments,and individual practitioners.Conclusion Given that most of the surveyed physicians integrated TCM with Western medicine in their clinical practices,the practice of“pure TCM”appears to be obsolete in China’s tertiary healthcare institutions.Notably,remarkable variation exists in the use of different TCM modalities across institutions and among individuals,which might be related to and thus limited by the practitioners’experience.Future research focusing on the efficacy and safety of TCM interventions for specific diseases,the development of standardized clinical guidelines,and the enhancement of TCM education and training are called for to optimize TCM-Western medicine integration.
基金supported by the National Social Science Fund of China(No.20CZX048)。
文摘In modal logic,topological semantics is an intuitive and natural special case of neighbourhood semantics.This paper stems from the observation that the satisfaction relation of topological semantics applies to subset spaces which are more general than topological spaces.The minimal modal logic which is strongly sound and complete with respect to the class of subset spaces is found.Soundness and completeness results of some famous modal logics(e.g.S4,S5 and Tr)with respect to various important classes of subset spaces(eg intersection structures and complete fields of sets)are also proved.In the meantime,some known results,e.g.the soundness and completeness of Tr with respect to the class of discrete topological spaces,are proved directly using some modifications of the method of canonical mode1,without a detour via neighbourhood semantics or relational semantics.
文摘This study examined gender differences in modal choice among residents of coastal communities of Yenagoa metropolis in Bayelsa State, Nigeria. The Four-Step model of transportation planning and modal choice provided the theoretical basis for this study. A survey research design involving a stratified sampling technique was adopted. The descriptives on transport modes, amount and time spent revealed that 10 (76.9%) males and 3 (23.1%) females preferred bicycle as means of transportation, 7 (58.3%) males and 5 (41.7%) females preferred motorcycle, while a significant proportion 90 (53.9%) males and 77 (46.1%) females preferred tricycle, 80 (63.0%) males and 47 (37.0%) females preferred cars/taxis, and 12 (46.2%) males and 14 (53.8%) females preferred mass transit bus. However, 14 (46.7%) males and 16 (53.3%) females in marshy terrain and coastal locations preferred canoes and boats. The result of the logistic regression model revealed that gender modal preference is more likely to be influenced by mode of transportation with a beta weight of 1.140, safety considerations 1.139, ownership of transport 1.135 and distance to place of work 1.073. Hence, this study recommends that a combination of these factors should be incorporated into transport planning to achieve effective transport planning and sustainable development in the Yenagoa metropolis.
基金supported by the National Natural Science Foundation of China(Nos.12304504,12304506 and U22 A2012)the Youth Innovation Promotion Association,Chinese Academy of Sciences(No.2021023)+1 种基金the Strategy Priority Research Program(Category B)of Chinese Academy of Sciences(Nos.XDB0700100 and XDB0700000)the Natural Science Foundation of Tianjin(No.22JCYBJC00070).
文摘Normal mode extraction has attracted extensive attention over the past few decades due to its practical value in enhancing the performance of underwater acoustic signal processing.Singular value decomposition(SVD)is an effective method to extract modal depth functions using vertical line arrays(VLA),particularly in scenarios when no prior environment information is available.However,the SVD method requires rigorous orthogonality conditions,and its performance severely degenerates in the presence of mode degeneracy.Consequently,the SVD approach is often not feasible in practical scenarios.This paper proposes a full rank decomposition(FRD)method to address these issues.Compared to the SVD method,the FRD method has three distinct advantages:1)the conditions that the FRD method requires are much easier to be fulfilled in practical scenarios;2)both modal depth functions and wavenumbers can be simultaneously extracted via the FRD method;3)the FRD method is not affected by the phenomenon of mode degeneracy.Numerical simulations are conducted in two types of waveguides to verify the FRD method.The impacts of environment configurations and noise levels on the precision of the extracted modal depth functions and wavenumbers are also investigated through simulation.
基金support from the National Natural Science Foundation of China(22179006)the National Key Research and Development Program of China(2024YFF0505900)+1 种基金the Key Research and Development Program of Henan province,China(231111242500)the SINOPEC project(223128)。
文摘Uneven lithium deposition leading to lithium dendrite growth severely hampers the application of lithium-metal batteries.Modifying the collector with lithiophilic materials helps improve lithium deposition.For lithophilic materials to modify the collector,the choice of cut-off voltage is very important.While excessively high cut-off voltages may compromise the stability of the modified layer and consequently disrupt ordered lithium deposition,conventional approaches typically employ lower cut-off voltages(particularly 0.1 V)to maintain modification layer stability.However,the 0.1 V cut-off voltage results in incomplete lithium stripping from the lithiophilic material surface.This phenomenon significantly diminishes the lithiophilic properties of the modified layer and consequently leads to substantial nucleation overpotential.Here,we propose to use a moderate cut-voltage stimulation effect to slow down the interfacial shielding effect of residual lithium metal on lithiophilic materials.By optimizing the cut-off voltage for the Cu@Sb_(2)S_(3)collector,the stability of the modified layer can be preserved while enabling the complete stripping of lithium metal from the surface of the lithophilic material.The asymmetric cell received the highest Coulombic efficiency(CE)when the lithium stripping cut-off voltage was set at 0.5 V relative to 0.1 and 2.0 V.At a current density of 1 mA cm^(-2)and a deposition capacity of1 m A h cm^(-2),the CE remained 98.6% at a cut-off voltage of 0.5 V after 140 cycles in an ether electrolyte without lithium nitrate.
基金the National Natural Science Foundation of China (Grant Nos.42072318 and 42207227)Central South University Innovation-Driven Research Program (Grant No.2023CXQD044).
文摘The soil-bentonite(SB)cut-off wall has been widely considered a vertical barrier to effectively control the migration of pollutants in contaminated sites.Recently,active porous materials have been used as a promising candidate amendment for mitigating chemical degradation and improving the retardation capacity of the SB cut-off wall.In this study,the silty clay from a typical Cr(VI)contaminated site was selected as the body material of the SB cut-off wall,and zeolite and active carbon were used as the modifiers of the silty clay-bentonite backfills,respectively.The impact of the two modifiers on the engineering properties of the backfills was investigated through a series of slump tests,consolidation tests,hydraulic conductivity tests,and microstructure tests.The experimental results demonstrated that the slump curves closely exhibited a linear relationship between standard slump and moisture content.Meanwhile,bentonite could improve the optimum moisture content of the backfills,while the addition of the two modifiers yielded the opposite outcome.As the bentonite content increased,the compression index of the backfills significantly increased,while the hydraulic conductivity decreased.At a given bentonite content of 5%,the addition of zeolite or active carbon resulted in a reduction in the compression index and initial void ratio,while exhibiting minimal impact on the hydraulic conductivity.Scanning electron microscope(SEM)observations indicated that the silty clay-bentonite backfills became increasingly loose with increasing bentonite content,owing to the filling and expansion of dispersed bentonite layers.The amendment of zeolite or active carbon was able to decrease the backfill volume by promoting the agglomeration of layered bentonite.The findings of this study will be useful for the optimal selection of backfill materials and the performance evaluation of the cut-off wall.
基金supported by the Chinese Ministry of Education of Humanities and Social Science Project(23YJC72040003)the Key Project of Chinese Ministry of Education(22JJD720021)supported by the Natural Science Foundation of Shandong Province,China(project number:ZR2023QF021)。
文摘In the present paper,we give a systematic study of the discrete correspondence the-ory and topological correspondence theory of modal meet-implication logic and moda1 meet-semilattice logic,in the semantics provided in[21].The special features of the present paper include the following three points:the first one is that the semantic structure used is based on a semilattice rather than an ordinary partial order,the second one is that the propositional vari-ables are interpreted as filters rather than upsets,and the nominals,which are the“first-order counterparts of propositional variables,are interpreted as principal filters rather than principal upsets;the third one is that in topological correspondence theory,the collection of admissi-ble valuations is not closed under taking disjunction,which makes the proof of the topological Ackermann 1emma different from existing settings.
基金financial support from several corporate sponsors.Contributions were made by the National Natural Science Foundation of China(Grant No.32071332)Shenzhen Science and Technology Innovation Project(Grant No.JCYJ20210324095802006)+2 种基金Ningbo Bureau of Science and Technology(Grant No.2023Z187)TransEasy Medical Tech.Co.,Ltd.(Grant No.2021114)Shenzhen University MedTech Innovation Fund(2023YG027).
文摘Aging is a persistent topic of interest,with skin aging as its most visible manifestation,characterized by a reduction in intact collagen and elastic fibers in the dermis.Hyaluronic acid,a vital component of the extracellular matrix present in the skin,has become a mainstream method for skin rejuvenation through injections.However,the rapid degradation of pure hyaluronic acid,combined with insufficient maintenance duration and often limited therapeutic effects,presents significant challenges for injectable treatments.Additionally,low patient compliance due to discomfort from needles penetrating the dermal layer further complicates its use.In this review,we summarize and compare existing interventions for skin aging,focusing on strategies to prolong the degradation cycle of hyaluronic acid,including variations in cross-linking modalities and injection techniques.We conclude that the injection of cross-linked modified hyaluronic acid via microneedles represents a promising approach to extend the degradation cycle,offering valuable insights for current therapeutic strategies.
基金supported by the National Natural Science Foundation of China(Nos.52401342 and 12572025)the Fundamental Research Funds for the Central Universities of China(Nos.D5000240076 and G2025KY05171)+1 种基金the Natural Science Basic Research Program of Shaanxi Province(No.2025JCYBMS-026)the Basic Research Programs of Taicang(No.TC2024JC36)。
文摘In recent years,scholars around the world have shown increasing interest in elastic support structures,leading to significant progress in dynamic modeling techniques for pipeline systems.Although multiple analytical approaches exist,engineers increasingly prioritize computationally efficient,precise low-order models for practical implementation.In order to address this need,this study develops an innovative nonlinear dynamic formulation for pipelines accounting for both foundation and boundary nonlinearities.The proposed solution methodology initiates with global mode extraction using the global mode technique,followed by a detailed implementation procedure.Model validation is conducted through a cantilever pipeline case study featuring nonlinear support conditions,where strong agreement between the proposed model's predictions and finiteelement benchmark solutions demonstrates its reliability.Subsequently,a comprehensive parametric study investigates the combined effects of foundation stiffness,boundary constraints,excitation intensity,and nonlinear interaction terms on the vibrational response of the cantilever pipe.This systematic approach yields critical insights for practical engineering designs and applications.
基金Projects(52278395,52208409) supported by the National Natural Science Foundation of ChinaProject(2022JJ40531) supported by the Natural Science Foundation of Hunan Province,China。
文摘Because of actual requirement,shield machine always excavates with an inclined angle in longitudinal direction.Since many previous studies mainly focus on the face stability of the horizontal shield tunnel,the effects of tensile strength cut-off and pore water pressure on the face stability of the longitudinally inclined shield tunnel are not well investigated.A failure mechanism of a longitudinally inclined shield tunnel face is constructed based on the spatial discretization technique and the tensile strength cut-off criterion is introduced to modify the constructed failure mechanism.The pore water pressure is introduced as an external force into the equation of virtual work and the objective function of the chamber pressure of the shield machine is obtained.Moreover,the critical chamber pressure of the longitudinally inclined shield tunnel is computed by optimal calculation.Parametric analysis indicates that both tensile strength cut-off and pore water pressure have a significant impact on the chamber pressure and the range of the collapse block.Finally,the theoretical results are compared with the numerical results calculated by FLAC3D software which proves that the proposed approach is effective.
文摘In this paper,the sentiment classification method of multimodal adversarial autoencoder is studied.This paper includes the introduction of the multimodal adversarial autoencoder emotion classification method and the experiment of the emotion classification method based on the encoder.The experimental analysis shows that the encoder has higher precision than other encoders in emotion classification.It is hoped that this analysis can provide some reference for the emotion classification under the current intelligent algorithm mode.
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.
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.
基金supported by grants from the High-Level Oversea Talent Introduction Plan,Chinathe Special Fund for Basic Scientific Research in Central Universities of China-Doctoral Research and Innovation Fund Project,China(No.3072023CFJ0206).
文摘Rotor blade is one of the most significant components of helicopters. But due to its highspeed rotation characteristics, it is difficult to collect the vibration signals during the flight stage.Moreover, sensors are highly susceptible to damage resulting in the failure of the measurement.In order to make signal predictions for the damaged sensors, an operational modal analysis(OMA) together with the virtual sensing(VS) technology is proposed in this paper. This paper discusses two situations, i.e., mode shapes measured by all sensors(both normal and damaged) can be obtained using OMA, and mode shapes measured by some sensors(only including normal) can be obtained using OMA. For the second situation, it is necessary to use finite element(FE) analysis to supplement the missing mode shapes of damaged sensor. In order to improve the correlation between the FE model and the real structure, the FE mode shapes are corrected using the local correspondence(LC) principle and mode shapes measured by some sensors(only including normal).Then, based on the VS technology, the vibration signals of the damaged sensors during the flight stage can be accurately predicted using the identified mode shapes(obtained based on OMA and FE analysis) and the normal sensors signals. Given the high degrees of freedom(DOFs) in the FE mode shapes, this approach can also be used to predict vibration data at locations without sensors. The effectiveness and robustness of the proposed method is verified through finite element simulation, experiment as well as the actual flight test. The present work can be further used in the fault diagnosis and damage identification for rotor blade of helicopters.
基金Project supported by the National Natural Science Foundation of China(Grant No.52336001)supported by the Tsinghua National Laboratory for Information Science and Technology.
文摘This study investigates cavitating swirling flow in a diffuser,i.e.,a simplified model of a Francis turbine draft tube,using proper orthogonal decomposition(POD)and dynamic mode decomposition(DMD)applied to velocity and pressure field data.The interaction between vortex rope precession and cavitation surge under varying swirl and cavitation numbers is analyzed.The modal analysis results depicted the coherent structures correlated to the vortex rope precession near the diffuser inlet and the diffuser outlet,and cavitation surge in the diffuser.The POD analysis accurately revealed the flow features in the diffuser:The conical structure represents the flow diffusion with vortex rope precession and the reverse core indicates the backflow in the diffuser for the averaged flow,and the double helical structure near the diffuser inlet for the representative flow oscillation.The typical coherent structures obtained by the DMD for the cavitating swirling flow in the diffuser are the double helical structure concentrated near the diffuser inlet.The double helical structure also appears near the diffuser outlet where the breakdown of vortex rope occurs and the flow oscillation slows down.Once cavitation occurs,the mode induced by cavitation surge and its corresponding coherent structure may change according to the operating condition.The flow oscillation can be changed from the double helical mode to the axial oscillation caused by cavitation surge named breathing mode if cavitation surge becomes strong enough at a small cavitation number or large swirl number.
基金the National Natural Science Foun-dation of China(Grant Nos.91963201 and 12174163)the 111 Project(Grant No.B20063).
文摘The lack of soft magnetic composites with high power density in MHz frequency range has become an obstacle in the efficient operation of the electrical and electronic equipments.Here,a promising method to increase the cut-off frequency of iron-based soft magnetic composites to hundreds of MHz is reported.The cut-off frequency is increased from 10 MHz to 1 GHz by modulating the height of the ring,the distribution of particles,and the particle size.The mechanism of cut-off frequency and permeability is the coherent rotation of domain modulated by inhomogeneous field due to the eddy current effect.An empirical formula for the cut-off frequency in a magnetic ring composed of iron-based particles is established from experimental data.This work provides an effective approach to fabricate soft magnetic composites with a cut-off frequency in hundreds of MHz.
