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Analytical Solutions for an Isotropic Elastic Half-Plane with Complete Surface Effects Subjected to a Concentrated/Uniform Surface Load

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Acta Mechanica Solida Sinica 2024年第3期37卷 371-384页

作者： Xia-Hui pan School of Civil Engineering Henan Polytechnic UniversityJiaozuo454003China

Within the context of Gurtin-Murdoch surface elasticity theory,closed-form analytical solutions are derived for an isotropic elastic half-plane subjected to a concentrated/uniform surface *** the effects of residual surface stress and surface elasticity are *** stress function method and Fourier integral transform technique are *** solutions are provided in a compact manner that can easily reduce to special situations that take into account either one surface effect or none at *** results indicate that surface effects generally lower the stress levels and smooth the deformation profiles in the *** elasticity plays a dominant role in the in-plane elastic fields for a tangentially loaded half-plane,while the effect of residual surface stress is fundamentally crucial for the out-of-plane stress and displacement when the half-plane is normally *** the remaining situations,combined effects of surface elasticity and residual surface stress should be *** results for a concentrated surface force serve essentially as fundamental solutions of the Flamant and the half-plane Cerruti problems with surface *** solutions presented in this work may be helpful for understanding the contact behaviors between solids at the nanoscale.

关键词： Surface effects Residual surface stress Surface elasticity Half-plane Analytical solutions

Serum Mac-2 binding protein glycosylation isomer level predicts hepatocellular carcinoma development in E-negative chronic hepatitis B patients

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World Journal of Gastroenterology 2019年第11期25卷 1398-1408页

作者： Lung-Yi Mak wai-pan to Danny Ka-Ho Wong James Fung Fen Liu wai-Kay Seto Ching-Lung Lai Man-Fung Yuen Department of Medicine Queen Mary Hospital Department of Medicine The University of Hong Kong State Key Laboratory for Liver Research The University of Hong Kong

BACKGROUND Liver cirrhosis is a major risk factor for hepatocellular carcinoma(HCC)development in chronic hepatitis B(CHB). Serum Mac-2 binding protein glycosylation isomer(M2 BPGi) is a novel serological marker for fibrosis. The role of M2 BPGi in prediction of HCC is *** To examine the role of serum M2 BPGi in predicting HCC development in hepatitis B e antigen(HBeAg)-negative *** Treatment-naive CHB patients with documented spontaneous HBeAg seroconversion were recruited. Serum M2 BPGi was measured at baseline(within3 years from HBeAg seroconversion), at 5 years and 10 years after HBeAg seroconversion and expressed as cut-off index(COI). Multivariate cox regression was performed to identify predictors for HCC development. ROC analysis was used to determine the cut-off value of M2 *** Among 207 patients(57% male, median age at HBeAg seroconversion 40 years old) with median follow-up of 13.1(11.8-15.5) years, the cumulative incidence of HCC at 15 years was 7%. Median M2 BPGi levels were significantly higher in patients with HCC compared to those without HCC(baseline: 1.39 COI vs 0.38 COI, P < 0.001; 5-year: 1.45 COI vs 0.47 COI, P < 0.001; 10-year: 1.20 COI vs 0.55 COI, P = 0.001). Multivariate analysis revealed age at HBeAg seroconversion[odds ratio(OR) = 1.196, 95% confidence interval(CI): 1.034-1.382, P = 0.016] and baseline M2 BPGi(OR = 4.666, 95%CI: 1.296-16.802, P = 0.018) were significant factors predictive of HCC. Using a cut-off value of 0.68 COI, baseline M2 BPGi yielded AUROC of 0.883 with 91.7% sensitivity and 80.8% *** High serum M2 BPGi within 3 years after HBeAg seroconversion was a strong predictor for subsequent HCC development in treatment-naive HBeAg-negative CHB patients.

关键词： Hepatocellular carcinoma Hepatitis B Liver fibrosis Mac-2 binding protein glycosylation isomer Biomarker

Aeroengine thrust estimation and embedded verification based on improved temporal convolutional network

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Chinese Journal of Aeronautics 2024年第1期37卷 106-117页

作者： Wanzhi MENG Zhuorui pan Sixin WEN pan QIN Ximing SUN Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian University of TechnologyDalian 116024China School of Control Science and Engineering Dalian University of TechnologyDalian 116024China

Thrust estimation is a significant part of aeroengine thrust control *** traditional estimation methods are either low in accuracy or large in *** further improve the estimation effect,a thrust estimator based on Multi-layer Residual Temporal Convolutional Network(M-RTCN)is *** solve the problem of dead Rectified Linear Unit(ReLU),the proposed method uses the Gaussian Error Linear Unit(GELU)activation function instead of ReLU in residual *** the overall architecture of the multi-layer convolutional network is adjusted by using residual connections,so that the network thrust estimation effect and memory consumption are further ***,the comparison with seven other methods shows that the proposed method has the advantages of higher estimation accuracy and faster convergence ***,six neural network models are deployed in the embedded controller of the micro-turbojet *** Hardware-in-the-Loop(HIL)testing results demonstrate the superiority of M-RTCN in terms of estimation accuracy,memory occupation and running ***,an ignition verification is conducted to confirm the expected thrust estimation and real-time performance.

关键词： Thrust estimation Temporal convolutional network Embedded deployment Hardware-in-the-loop testing Ignition verification

Interplay of laser power and pore characteristics in selective laser melting of ZK60 magnesium alloys:A study based on in-situ monitoring and image analysis

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Journal of Magnesium and Alloys 2024年第4期12卷 1346-1366页

作者： Weijie Xie Hau-Chung Man Chi-wai Chan Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHong KongChina School of Mechanical and Aerospace Engineering Queen’s UniversityBelfast BT95AHUK Research Institute for Advanced Manufacturing The Hong Kong Polytechnic UniversityHong KongChina

This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)***-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 *** morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore *** laser power led to increased pore coverage,whereas a denser structure was observed at higher laser *** laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the *** increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore *** laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher *** interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys.

关键词： Selective laser melting(SLM) Magnesium(Mg)alloys Biodegradable implants Porosity In-situ monitoring

Defined hydrogels for spinal cord organoids:challenges and potential applications

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Neural Regeneration Research 2024年第11期19卷 2329-2330页

作者： wai Hon Chooi Yuewen Wu Shi-Yan Ng Institute of Molecular and Cell Biology(IMCB) Agency for ScienceTechnology and Research(A*STAR)SingaporeSingapore Department of Physiology Yong Loo Lin School of MedicineNational University of Singapore(NUS)SingaporeSingapore

Organoids of the central nervous system,primarily derived from pluripotent stem cells or neural stem cells,are three-dimensional tissue cultures with self-organizing *** exposed to the right combinations of signals,they differentiate into a 3D tissue consisting of complex cytoarchitecture and native cell types,including various neuron subtypes and glial *** features closely mimic native tissues,making them invaluable for developmental studies and disease *** recent years,spinal cord organoids(SCOs)have been developed to investigate spinal cord development,injuries,and various neurological *** an integral part of the central nervous system,SCOs play a vital role and serve as a site for studying both neurodevelopment and neurodegenerative diseases.

关键词： properties injuries primarily

New opportunities for ferroelectric deep-UV nonlinear optical crystals

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Science China Materials 2024年第3期67卷 1004-1005页

作者： Miriding Mutailipu Shilie pan Research Center for Crystal Materials Xinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi 830011China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Deep-ultraviolet(deep-UV)light with the wavelength below200 nm is one of the most crucial elements of both laser-driven industrial and scientific applications in recent years[1].DeepUV light has been produced using a variety of techniques,such as gas discharge lamps,synchrotron radiation,excimer lasers,free electron lasers,and nonlinear frequency conversion.

关键词： nonlinear optical ferroelectric

Detection of Turbulence Anomalies Using a Symbolic Classifier Algorithm in Airborne Quick Access Record(QAR)Data Analysis

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Advances in Atmospheric Sciences 2024年第7期41卷 1438-1449页

作者： Zibo ZHUANG Kunyun LIN Hongying ZHANG Pak-wai CHAN Flight Academy Civil Aviation University of ChinaTianjin 300300China School of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China Aviation Weather Services Hong Kong ObservatoryHong KongChina

As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation *** eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil *** study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)*** detection of atmospheric turbulence is approached as an anomaly detection *** evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence ***,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently *** summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning *** finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.

关键词： turbulence detection symbolic classifier quick access recorder data

A Time-Domain Numerical Simulation for Free Motion Responses of Two Ships Advancing in Head Waves

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China Ocean Engineering 2024年第3期38卷 519-530页

作者： pan Su-yong CHENG Yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The constant panel method within the framework of potential flow theory in the time domain is developed for solving the hydrodynamic interactions between two parallel ships with forward *** solving problems within a time domain framework,the free water surface needs to simultaneously satisfy both the kinematic and dynamic boundary conditions of the free water *** provides conditions for adding artificial damping *** the Runge−Kutta method to solve equations related to *** upwind differential scheme is used in the present method to deal with the convection terms on the free surface to prevent waves *** the comparison with the available experimental data and other numerical methods,the present method is proved to have good mesh convergence,and satisfactory results can be *** constant panel method is applied to calculate the hydrodynamic interaction responses of two parallel ships advancing in head *** simulations are conducted on the effects of forward speed,different longitudinal and lateral distances on the motion response of two modified Wigley ships in head *** further investigations are conducted on the effects of different ship types on the motion response.

关键词： ship motions time domain simulation forward speed different distances wave loads

Cooperative Target Fencing of Multiple Vehicles for a General Target with Connectivity Preservation and Collision Avoidance

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Journal of Systems Science & Complexity 2024年第1期37卷 136-151页

作者： pan Zini CHEN Ben M Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem for n-dimensional systems and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull formed by the ***,the dynamics of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the communication network and collision avoidance among the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a numerical example.

关键词： Multi-agent systems networked systems target fencing