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A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： Wei WEI Feng GUAN Xin FANG college of Intelligent Science National University of Defense Technology naval Research Academy

A metamaterial vibration isolator, termed as wave-insulating isolator, is proposed, which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave insulation. It consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and narrow. The bandgap mechanisms, vibration isolation properties, effects of key parameters, and robustness to complex conditions are clarified. As experimentally demonstrated, the wave-insulating isolator can improve the vibration insulation in the ranges of [50 Hz, 180 Hz] and [260 Hz,400 Hz] by 15 dB and 25 dB, respectively, in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate O328 34A30 74K20

Molecular dynamics simulation of the flow mechanism of shear-thinning fluids in a microchannel

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Chinese Physics B 2024年第4期33卷 516-525页

作者：杨刚郑庭程启昊张会臣 naval Architecture and Ocean Engineering college Dalian Maritime UniversityDalian 116026China

Shear-thinning fluids have been widely used in microfluidic systems,but their internal flow mechanism is still ***,in this paper,molecular dynamics simulations are used to study the laminar flow of shear-thinning fluid in a *** validated the feasibility of our simulation method by evaluating the mean square displacement and Reynolds number of the solution *** results show that the change rule of the fluid system's velocity profile and interaction energy can reflect the shear-thinning characteristics of the *** velocity profile resembles a top-hat shape,intensifying as the fluid's power law index *** interaction energy between the wall and the fluid decreases gradually with increasing velocity,and a high concentration of non-Newtonian fluid reaches a plateau ***,the velocity profile of the fluid is related to the molecule number density distribution and their values are inversely *** analyzing the radial distribution function,we found that the hydrogen bonds between solute and water molecules weaken with the increase in *** observation offers an explanation for the shear-thinning phenomenon of the non-Newtonian flow from a micro perspective.

关键词： molecular dynamics simulation non-Newtonian fluid microchannel shear-thinning

Online task planning method of anti-ship missile based on rolling optimization

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Journal of Systems Engineering and Electronics 2024年第3期35卷 720-731页

作者： LU Faxing DAI Qiuyang YANG Guang JIA Zhengrong college of Weaponry Engineering Naval University of EngineeringWuhan 430033China

Based on the wave attack task planning method in static complex environment and the rolling optimization framework, an online task planning method in dynamic complex environment based on rolling optimization is proposed. In the process of online task planning in dynamic complex environment,online task planning is based on event triggering including target information update event, new target addition event, target failure event, weapon failure event, etc., and the methods include defense area reanalysis, parameter space update, and mission re-planning. Simulation is conducted for different events and the result shows that the index value of the attack scenario after re-planning is better than that before re-planning and according to the probability distribution of statistical simulation method, the index value distribution after re-planning is obviously in the region of high index value, and the index value gap before and after re-planning is related to the degree of posture change.

关键词： target allocation of anti-ship missile defense area rolling optimization task re-planning

MetaPINNs:Predicting soliton and rogue wave of nonlinear PDEs via the improved physics-informed neural networks based on meta-learned optimization

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Chinese Physics B 2024年第2期33卷 96-107页

作者：郭亚楠曹小群宋君强冷洪泽 college of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China college of Computer National University of Defense TechnologyChangsha 410073China naval Aviation University Huludao 125001China

Efficiently solving partial differential equations(PDEs)is a long-standing challenge in mathematics and physics *** recent years,the rapid development of artificial intelligence technology has brought deep learning-based methods to the forefront of research on numerical methods for partial differential *** them,physics-informed neural networks(PINNs)are a new class of deep learning methods that show great potential in solving PDEs and predicting complex physical *** the field of nonlinear science,solitary waves and rogue waves have been important research *** this paper,we propose an improved PINN that enhances the physical constraints of the neural network model by adding gradient information *** addition,we employ meta-learning optimization to speed up the training *** apply the improved PINNs to the numerical simulation and prediction of solitary and rogue *** evaluate the accuracy of the prediction results by error *** experimental results show that the improved PINNs can make more accurate predictions in less time than that of the original PINNs.

关键词： physics-informed neural networks gradient-enhanced loss function meta-learned optimization nonlinear science

The gasdermin family:emerging therapeutic targets in diseases

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Signal Transduction and Targeted Therapy 2024年第5期9卷 1905-1937页

作者： Chenglong Zhu Sheng Xu Ruoyu Jiang Yizhi Yu Jinjun Bian Zui Zou Faculty of Anesthesiology Changhai HospitalNaval Medical UniversityShanghai 200433China School of Anesthesiology Naval Medical UniversityShanghai 200433China National Key Laboratory of Immunity&Inflammation Naval Medical UniversityShanghai 200433China d 4 Department of Biochemistry and Molecular Biology College of Basic Medical SciencesNaval Medical UniversityShanghai 200433China

The gasdermin(GSDM)family has garnered significant attention for its pivotal role in immunity and disease as a key player in *** recently characterized class of pore-forming effector proteins is pivotal in orchestrating processes such as membrane permeabilization,pyroptosis,and the follow-up inflammatory response,which are crucial self-defense mechanisms against irritants and *** have been implicated in a range of diseases including,but not limited to,sepsis,viral infections,and cancer,either through involvement in pyroptosis or independently of this *** regulation of GSDM-mediated pyroptosis is gaining recognition as a promising therapeutic strategy for the treatment of various *** strategies for inhibiting GSDMD primarily involve binding to GSDMD,blocking GSDMD cleavage or inhibiting GSDMD-N-terminal(NT)oligomerization,albeit with some off-target *** this review,we delve into the cutting-edge understanding of the interplay between GSDMs and pyroptosis,elucidate the activation mechanisms of GSDMs,explore their associations with a range of diseases,and discuss recent advancements and potential strategies for developing GSDMD inhibitors.

关键词： diseases therapeutic immunity

An Innovative Coupled Common-Node Discrete Element Method-Smoothed Particle Hydrodynamics Model Developed with LS-DYNA and Its Applications

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China Ocean Engineering 2024年第3期38卷 467-482页

作者： SHEN Zhong-xiang WANG Wen-qing XU Cheng-yue LUO Jia-xin LIU Ren-wei School of naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China college of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China

In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SPH)method is developed using LS-DYNA *** DEM and SPH are established on the same node to create common-node DEM-SPH particles,allowing for fluid–structure *** simulations of various scenarios,including water entry of a rigid sphere,dam-break propagation over wet beds,impact on an ice plate floating on water and ice accumulation on offshore structures,are *** interaction between DS particles and SPH fluid and the crack generation mechanism and expansion characteristics of the ice plate under the interaction of structure and fluid are also *** results are compared with available data to verify the proposed coupling ***,the simulation results demonstrated that controlling the cutoff pressure of internal SPH particles could effectively control particle splashing during ice crushing failure.

关键词： common-node DEM-SPH fluid-structure interaction discrete element method smoothed particle hydrodynamics

Predicting hepatocellular carcinoma: A new non-invasive model based on shear wave elastography

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World Journal of Gastroenterology 2024年第25期30卷 3166-3178页

作者： Dong Jiang Yi Qian Yi-Jun Gu Ru Wang Hua Yu Hui Dong Dong-Yu Chen Yan Chen Hao-Zheng Jiang Bi-Bo Tan Min Peng Yi-Ran Li Department of Ultrasound Eastern Hepatobiliary Surgery HospitalThe Third Affiliated Hospital of Naval Medical UniversityShanghai 200433China Department of Pathology Shanghai Eastern Hepatobiliary Surgery HospitalThird Affiliated Hospital of Naval Medical UniversityShanghai 200433China Department of college of Art and Science Case Western Reserve UniversityClevelandOH 44106United States Ultrasound Diagnosis PLA Naval Medical CenterShanghai 200437China

BACKGROUND Integrating conventional ultrasound features with 2D shear wave elastography(2D-SWE)can potentially enhance preoperative hepatocellular carcinoma(HCC)*** To develop a 2D-SWE-based predictive model for preoperative identification of *** A retrospective analysis of 884 patients who underwent liver resection and pathology evaluation from February 2021 to August 2023 was conducted at the Oriental Hepatobiliary Surgery *** patients were divided into the modeling group(n=720)and the control group(n=164).The study included conventional ultrasound,2D-SWE,and preoperative laboratory *** logistic regression was used to identify independent predictive factors for RESULTS In the modeling group analysis,maximal elasticity(Emax)of tumors and their peripheries,platelet count,cirrhosis,and blood flow were independent risk indicators for *** factors yielded an area under the curve of 0.77(95%confidence interval:0.73-0.81)with 84%sensitivity and 61%*** model demonstrated good calibration in both the construction and validation cohorts,as shown by the calibration graph and Hosmer-Lemeshow test(P=0.683 and P=0.658,respectively).Additionally,the mean elasticity(Emean)of the tumor periphery was identified as a risk factor for microvascular invasion(MVI)in malignant liver tumors(P=0.003).Patients receiving antiviral treatment differed significantly in platelet count(P=0.002),Emax of tumors(P=0.033),Emean of tumors(P=0.042),Emax at tumor periphery(P<0.001),and Emean at tumor periphery(P=0.003).CONCLUSION 2D-SWE’s hardness value serves as a valuable marker for enhancing the preoperative diagnosis of malignant liver lesions,correlating significantly with MVI and antiviral treatment efficacy.

关键词： Shear wave elastography Predicting model Microvascular invasion Antiviral treatment Hepatocellular carcinoma

Existence of long-range magnetic order in Heisenberg spin nanoribbons with edge modification

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Communications in Theoretical Physics 2024年第07期76卷 136-146页

作者： Da-cheng Ma Ling-yi Cui Chu-xiao Sun Xiao-dan Chi Zheng-Nan XianYu An Du college of Science Northeastern University Department of Basic Science Dalian Naval Academy Department of Physics College of Sciences Shenyang University of Chemical Technology National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern University Key Laboratory of Data Analytics and Optimization for Smart Industry(Northeastern University) Ministry of Education

Long-range magnetic order appears on a side decorated Heisenberg spin nanoribbon at nonzero temperature, although no spontaneous magnetization exists in a one-or two-dimensional isotropic Heisenberg model at any nonzero temperature according to the Mermin–Wagner theorem. By use of the spin Green's function method, we calculated the magnetizations of Heisenberg nanoribbons decorated by side spins with single-ion anisotropy and found that the system exhibits a nonzero transition temperature, whether the decorated edge spins of the system link together or separate from each other. When the width of the nanoribbon achieves infinite limit, the transition temperatures of the system tend to the same finite constant eventually whether one edge or both edges are decorated by side spins in the nanoribbon. The results reveal that the magnetism of a low-dimensional spin system is different from that of a three-dimensional spin system. When the single-ion anisotropy of edge spins in a Heisenberg spin nanoribbon can be modulated by an electric field experimentally, various useful long-range magnetic orders of the system can be obtained. This work can provide a detailed theoretical basis for designing and fabricating next-generation low-dimensional magnetic random-access memory.

关键词： Heisenberg model long-range magnetic order magnetic anisotropy Nanoribbon transition temperature

Westward Migration of Tropical Cyclone Activity in the Western North Pacific during 1982–2020:Features and Possible Causes

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Journal of Meteorological Research 2024年第1期38卷 1-9页

作者： Jian ZHONG Huadong DU Yuqin WU Yuehua PENG China Satellite Maritime Tracking and Control Department Jiangyin 2144312 college of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 4100733 Dalian naval Academy Dalian 1160184 Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029

The westward migration of tropical cyclone(TC)activity has been identified in the western North Pacific(WNP),but the related features and causes remain ***,based on the best track data from China,Japan,and the US,and the NCEP–NCAR reanalysis data in 1982–2020,we investigate characteristics of the westward migration of the WNP TC activity with various metrics,and reveal possible causes for the migration of TC tracks through analyzing its seasonality and dependence on environmental *** results show that the WNP TCs show significant westward migrations in a number of metrics,including location of tracks,genesis,the first track point at which TC reaches its lifetime-maximum intensity,and the last track point in the TC *** is found that TC tracks exhibit more significant westward migrations in the easterly steering flow than in the westerly steering ***,the TC longitude shift shows notable seasonal variations,for which the TCs in the easterlies move further west than those in the westerlies during July–September,vice versa during October–*** dependence of the westward migration of TC tracks on background steering flow is associated with the different environmental *** westward shift in the westerly steering is mainly due to the reduced vertical wind shear(VWS),while the weakened zonal easterly steering and reduced VWS are both closely related to the westward migration in the easterly *** results have important implications for understanding current and future variations in TC longitude shift.

关键词： tropical cyclone westward migration steering flow vertical wind shear