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Concurrent generation and amplification of longitudinal and bending waves using defective phononic crystals

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Applied Mathematics and Mechanics(English Edition) 2025年第2期46卷 269-288页

作者： S.h.JO Department of Mechanical Robotics and Energy Engineering Dongguk University

Defective phononic crystals (PnCs) have enabled spatial localization and quantitative amplification of elastic wave energy. Most previous research has focused on applications such as narrow-bandpass filters, ultrasonic sensors, and piezoelectric energy harvesters, typically operating under the assumption of an external elastic wave incidence. Recently, a novel approach that uses defective PnCs as ultrasonic actuators to generate amplified waves has emerged. however, the existing studies are limited to the generation of either longitudinal or bending waves, with no research addressing the concurrent generation of both. hence, this paper proposes a straightforward methodology for the concurrent generation and amplification of both wave types utilizing defect modes at independent defect-band frequencies. Bimorph piezoelectric elements are attached to the defect, with each element connected to independent external voltage sources. By precisely adjusting the magnitude and temporal phase differences between the voltage sources, concurrently amplified wave generation is achieved. The paper highlights the advantages of the proposed analytical model. This model is both computationally timeefficient and accurate, in comparison with the COMSOL simulation results. For instance,in case studies, the analytical model reduces the computational time from one hour to mere seconds, while maintaining acceptable error rates of 1%in peak frequencies. This concurrent wave-generation methodology opens new avenues for applications in rotating machinery fault diagnosis, structural health monitoring, and medical imaging.

关键词： phononic crystal (PnC) defect concurrent generation piezoelectric ultrasonic actuator O328 O346

Continuously adjustable mechanical metamaterial based on planetary gear trains and external meshing gears

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Applied Mathematics and Mechanics(English Edition) 2025年第2期46卷 233-252页

作者： Shuai MO Xu TANG Keren ChEN h. hOUJOh Wei ZhANG State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures School of Mechanical Engineering Guangxi University State Key Laboratory of Precision Manufacturing for Extreme Service Performance Central South University State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Precision and Intelligence Laboratory Tokyo Institute of Technology

The metamaterial based on external meshing gears(MEG) is designed based on the principle of external meshing gear transmission. Based on the meshing transmission principle of external meshing gears and planetary gear trains, the internal and external gear rings are designed. Based on the internal and external gear rings, the metamaterial based on inner and outer planetary gear trains(MIP) is designed to study the shear modulus, Young's modulus, and amplitude-frequency characteristics of the metamaterial based on gears at different angles. The effects of the number of planetary gears on the physical characteristics of the MIP are studied. The results show that the MEG can be continuously adjusted by adjusting the shear modulus and Young's modulus due to its meshing characteristics. With the same number of gears, the adjustment range of the MIP is larger than the adjustment range of the MEG. When the number of planetary gears increases, the adjustment range of the MIP decreases. Moreover, when the metamaterial based on gears rotates, the harmonic response changes with the change of the angle.

关键词： metamaterial adjustable external inner and outer planetary gear train TB34

Innovative approaches in predicting outcomes for rectal neuroendocrine tumors

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World Journal of Gastroenterology 2025年第6期31卷 126-131页

作者： Mahmoud Nassar Bahaaeldin Baraka Andrew h Talal Department of Internal Medicine Jacobs School of Medicine and Biomedical SciencesUniversity of BuffaloBuffaloNY 14221United States Department of Research American Society for InclusionDiversityand Equity in HealthcareLewesDE 19958United States Medical Oncologist OncologyNottingham University HospitalsCity HospitalNottingham NG51PBUnited Kingdom Department of Medicine University at BuffaloState University of New YorkBuffaloNY 14203United State

Rectal neuroendocrine neoplasms pose significant challenges due to their varied presentations and *** prognostic models,while useful,often fall short of accurately predicting clinical outcomes for these *** article discusses the development and implications of a novel prognostic tool,the GATIS score,which aims to enhance predictive accuracy and guide treatment strategies more effectively than current *** data from a large cohort and employing sophisticated statistical models,the GATIS score integrates clinical and pathological markers to provide a nuanced assessment of *** evaluate the potential of this score to transform clinical decision-making processes,its integration into current medical practices,and future directions for its *** integration of genetic markers and other biomarkers could further refine its predictive power,highlighting the ongoing need for innovation in the management of rectal neuroendocrine neoplasms.

关键词： Rectal neuroendocrine tumors GATIS score Tumor staging Rectal neuroendocrine neoplasms Survival prediction Prognostic assessment Biomarkers Neuroendocrine carcinoma

Deep ResNet Strategy for the Classification of Wind Shear Intensity Near Airport Runway

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Computer Modeling in Engineering & Sciences 2025年第2期142卷 1565-1584页

作者： Afaq Khattak Pak-wai Chan Feng Chen Abdulrazak h.Almaliki Department of Civil Structural and Environmental EngineeringTrinity College DublinDublinD02 PN40Ireland hong Kong Observatory 134A Nathan RoadKowloonHong Kong999077China College of Transportation Engineering Tongji UniversityShanghai201804China Department of Civil Engineering College of EngineeringTaif UniversityTaif21944Saudi Arabia

Intense wind shear(I-WS)near airport runways presents a critical challenge to aviation safety,necessi-tating accurate and timely classification to mitigate risks during takeoff and *** study proposes the application of advanced Residual Network(ResNet)architectures including ResNet34 and ResNet50 for classifying I-WS and Non-Intense Wind Shear(NI-WS)events using Doppler Light Detection and Ranging(LiDAR)data from hong Kong International Airport(hKIA).Unlike conventional models such as feedforward neural networks(FNNs),convolutional neural networks(CNNs),and recurrent neural networks(RNNs),ResNet provides a distinct advantage in addressing key challenges such as capturing intricate WS dynamics,mitigating vanishing gradient issues in deep architectures,and effectively handling class imbalance when combined with Synthetic Minority Oversampling Technique(SMOTE).The analysis results revealed that ResNet34 outperforms other models with a Balanced Accuracy of 0.7106,Probability of Detection of 0.8271,False Alarm Rate of 0.328,F1-score of 0.7413,Matthews Correlation Coefficient of 0.433,and Geometric Mean of 0.701,demonstrating its effectiveness in classifying I-WS *** findings of this study not only establish ResNet as a valuable tool in the domain of WS classification but also provide a reliable framework for enhancing operational safety at airports.

关键词： Aviation safety wind shear deep residual network Doppler LiDAR

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-TALOOKOLAEI h.GhANDVAR E.JUMAEV S.KhATIR T.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and Technology Solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

关键词： double curved beam finite element method functionally graded porous (FGP) material intermediate straight beam O313 vibration analysis

Plant-substrate biochar properties critical for mediating reductive debromination of 1,2-dibromoethane

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Journal of Environmental Sciences 2025年第1期147卷 1-10页

作者： Jonathan h.Lindhardt Peter E.holm Yong-Guan Zhu Changyong Lu hans Christian B.hansen Department of Plant and Environmental Sciences Faculty of ScienceUniversity of CopenhagenThorvaldsensvej 401871 Frederiksberg CDenmark Key lab of Urban Environment and health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Sino-Danish Center for education and research China and DenmarkDalgas Avenue 4DK-8000 Aarhus C.Denmark

Dibromoethane is a widespread,persistent organic *** are known mediators of reductive dehalogenation by layered Fe^(Ⅱ)-Fe^(Ⅲ)hydroxides(green rust),which can reduce 1,2-dibromoethane to innocuous bromide and ***,the critical characteristics that determine mediator functionality are lesser *** biochar substrates were pyrolyzed at 600℃and 800℃,characterized by elemental analysis,X-ray photo spectrometry C and N surface speciation,X-ray powder diffraction,specific surface area analysis,and tested for mediation of reductive debromination of 1,2-dibromoethane by a green rust reductant under anoxic conditions.A statistical analysis was performed to determine the biochar properties,critical for debromination kinetics and total debromination *** was shown that selected plant based biochars can mediate debromination of 1,2-dibromoethane,that the highest first order rate constant was 0.082/hr,and the highest debromination extent was 27%in reactivity experiments with 0.1μmol(20μmol/L)1,2-dibromoethane,≈22 mmol/L Fe^(Ⅱ)GR,and 0.12 g/L soybean meal biochar(7 days).Contents of Ni,Zn,N,and P,and the relative contribution of quinone surface functional groups were significantly(ph 1,2-dibromoethane debromination,while adsorption,specific surface area,and the relative contribution of pyridinic N oxide surface groups were significantly negatively correlated with debromination.

关键词： Environmental remediation Biochar Persistent organic pollutants(POPs) Environmental catalysis Green rust

From Imperfection to Perfection: Advanced 3D Facial Reconstruction Using MICA Models and Self-Supervision Learning

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Computer Modeling in Engineering & Sciences 2025年第2期142卷 1459-1479页

作者： Thinh D.Le Duong Q.Nguyen Phuong D.Nguyen h.Nguyen-Xuan CIRTECh Institute HUTECH UniversityHo Chi Minh City72308Viet Nam

Research on reconstructing imperfect faces is a challenging *** this study,we explore a data-driven approach using a pre-trained MICA(MetrIC fAce)model combined with 3D printing to address this *** propose a training strategy that utilizes the pre-trained MICA model and self-supervised learning techniques to improve accuracy and reduce the time needed for 3D facial structure *** results demonstrate high accuracy,evaluated by the geometric loss function and various statistical *** showcase the effectiveness of the approach,we used 3D printing to create a model that covers facial *** findings indicate that our method produces a model that fits well and achieves comprehensive 3D facial *** technique has the potential to aid doctors in treating patients with facial injuries.

关键词： 3D face reconstruction self-supervised learning face defect 3D printed prototypes

Origin of superlubricity of diamond-like carbon(DLC)

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Friction 2025年第1期13卷 85-99页

作者： Seokhoon Jang Zhe Chen Seong h.Kim Department of Chemical Engineering and Materials Research Institute Pennsylvania State UniversityUniversity ParkPA 16802USA State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China

hydrogenated diamond-like carbon(h-DLC)is typically produced as a coating or thin film through plasma-enhanced chemical vapor deposition(PE-CVD).h-DLC is relatively hard and well known to exhibit *** superlubricity an intrinsic property of h-DLC?This paper argues that h-DLC is not intrinsically superlubricious,but it has an ideal structure that allows transition of the interface region to a superlubricious structure upon frictional shear in proper ***,its superlubricity is an extrinsic *** argument is made by comparing frictional behaviors of three allotropes of carbon materials—graphite,amorphous carbon(a-C),and diamond,and carefully scrutinizing the run-in behavior as well as environment sensitivity of h-DLC *** superlubricious structure is generally known to be graphitic,but its exact structure remains elusive and is subject to further ***,accurate knowledge of how superlubricity is induced for h-DLC can guide engineering design to achieve superlubricious behaviors with other carbon materials produced via different synthetic routes.

关键词： superlubricity diamond-like carbon(DLC) run-in environmental sensitivity

New breakthrough:Building non-markovian environments for single-qubit systems at any time interval

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Science China(Physics,Mechanics & Astronomy) 2025年第3期68卷 189-189页

作者： h.Z.Shen Center for Quantum Sciences and School of Physics Northeast Normal UniversityChangchun130024China

The proposal of quantum simulation provides a highly effective approach for experimental research on open quantum *** date,numerous quantum simulation studies pertaining to open quantum systems have been put forward,including Fanchini et al.’s simulation of a dephasing noise channel utilizing an optical system[1],and Xiong et al.’s realization of a quantum simulation for a non-rotating-wave approximation noise channel,also leveraging an optical system[2].

关键词： quantum system breakthrough

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