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Progressive fragmentation of granular assemblies within rockslides: Insights from discrete-continuous numerical modeling

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Journal of Mountain Science 2024年第4期21卷 1174-1189页

作者： jiang hui ZHOU Yuande WANG Jinting DU Xiuli HUANG Hailong Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China. Key Laboratory of the Hydrosphere Sciences of the Ministry of Water Resources Tsinghua UniversityBeijing 100084China China Three Gorges Construction Management Co. Ltd.Chengdu 610000China

Rock fragmentation plays a critical role in rock avalanches,yet conventional approaches such as classical granular flow models or the bonded particle model have limitations in accurately characterizing the progressive disintegration and kinematics of multi-deformable rock blocks during rockslides.The present study proposes a discrete-continuous numerical model,based on a cohesive zone model,to explicitly incorporate the progressive fragmentation and intricate interparticle interactions inherent in rockslides.Breakable rock granular assemblies are released along an inclined plane and flow onto a horizontal plane.The numerical scenarios are established to incorporate variations in slope angle,initial height,friction coefficient,and particle number.The evolutions of fragmentation,kinematic,runout and depositional characteristics are quantitatively analyzed and compared with experimental and field data.A positive linear relationship between the equivalent friction coefficient and the apparent friction coefficient is identified.In general,the granular mass predominantly exhibits characteristics of a dense granular flow,with the Savage number exhibiting a decreasing trend as the volume of mass increases.The process of particle breakage gradually occurs in a bottom-up manner,leading to a significant increase in the angular velocities of the rock blocks with increasing depth.The simulation results reproduce the field observations of inverse grading and source stratigraphy preservation in the deposit.We propose a disintegration index that incorporates factors such as drop height,rock mass volume,and rock strength.Our findings demonstrate a consistent linear relationship between this index and the fragmentation degree in all tested scenarios.

关键词： Rock fragmentation Rockslide Numerical modelling Discrete-continuous modelling Runout Cohesive zone model

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Do nocturnal birds use acoustic and visual cues to avoid predation by bats?

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Integrative Zoology 2024年第3期19卷 524-537页

作者： Lixin GONG Huan WU Zhiqiang WANG hui WU jiang FENG Tinglei jiang Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization Northeast Normal UniversityChangchunChina Key Laboratory of Vegetation Ecology of Education Ministry Institute of Grassland ScienceNortheast Normal UniversityChangchunChina College of Life Science Jilin Agricultural UniversityChangchunChina

Anti-predation strategies are critical to animal survival and are fundamental to deciphering predator–prey interactions.As an important defense strategy,sensory predator detection(such as through acoustic and visual cues)enables animals to assess predation risk and execute predator-avoidance behavior;however,there are limited studies on the anti-predation behavior of nocturnal animals.The prey of bats provides an excellent representative system for examining the anti-predation behavior of nocturnal animals.Here,we broadcasted different types of echolocation calls of the bird-eating bat Ia io to two wild passerine birds,namely,Zosterops japonicus and Sinosuthora webbiana,that are preyed upon by I.io,and presented the birds with individual bats under different light intensities.The results showed that both bird species were able to perceive the low-frequency audible portion of the bats’echolocation calls;however,they did not exhibit escape responses to the acoustic stimuli.In the dark and under moonlit conditions,both bird species were unable to respond to active bats at close range and the birds only exhibited evasive flight behavior when bats approached or touched them.These results suggest that nocturnal passerine birds may not be able to use acoustic or visual cues to detect bats and adopt evasive maneuvers to avoid predation.This work suggests that bat predation pressure may not elicit primary predator-avoidance responses in nocturnal passerine birds.The results provide new insights into the anti-predation behavior of nocturnal animals.

关键词： anti-predation behavior nocturnal animals sensory cues sensory defenses

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Classifying Chinese Medicine Constitution Using Multimodal Deep-Learning Model

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Chinese Journal of Integrative Medicine 2024年第2期30卷 163-170页

作者： GU Tian-yu YAN Zhuang-zhi jiang Jie-hui School of Communication&Information Engineering Shanghai UniversityShanghai(200444)China School of Life Science Shanghai UniversityShanghai(200444)China

Objective:To develop a multimodal deep-learning model for classifying Chinese medicine constitution,i.e.,the balanced and unbalanced constitutions,based on inspection of tongue and face images,pulse waves from palpation,and health information from a total of 540 subjects.Methods:This study data consisted of tongue and face images,pulse waves obtained by palpation,and health information,including personal information,life habits,medical history,and current symptoms,from 540 subjects(202 males and 338 females).Convolutional neural networks,recurrent neural networks,and fully connected neural networks were used to extract deep features from the data.Feature fusion and decision fusion models were constructed for the multimodal data.Results:The optimal models for tongue and face images,pulse waves and health information were ResNet18,Gate Recurrent Unit,and entity embedding,respectively.Feature fusion was superior to decision fusion.The multimodal analysis revealed that multimodal data compensated for the loss of information from a single mode,resulting in improved classification performance.Conclusions:Multimodal data fusion can supplement single model information and improve classification performance.Our research underscores the effectiveness of multimodal deep learning technology to identify body constitution for modernizing and improving the intelligent application of Chinese medicine.

关键词： Chinese medicine constitution classification multimodal deep learning tongue image face image pulsewave health information

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Study on a conical bearing for acceleration-sensitive equipment

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 103-128页

作者： Pang hui Xu Wen Dai Junwu jiang Tao Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China School of Civil Engineering and Transportation Beihua UniversityJilin 132013China

Seismic isolation effectively reduces seismic demands on building structures by isolating the superstructure from ground vibrations during earthquakes.However,isolation strategies give less attention to acceleration-sensitive systems or equipment.Meanwhile,as the isolation layer’s displacement grows,the stiffness and frequency of traditional rolling and sliding isolation bearings increases,potentially causing self-centering and resonance concerns.As a result,a new conical pendulum bearing has been selected for acceleration-sensitive equipment to increase self-centering capacity,and additional viscous dampers are incorporated to enhance system damping.Moreover,the theoretical formula for conical pendulum bearings is supplied to analyze the device’s dynamic parameters,and shake table experiments are used to determine the proposed device’s isolation efficiency under various conditions.According to the test results,the newly proposed devices have remarkable isolation performance in terms of minimizing both acceleration and displacement responses.Finally,a numerical model of the isolation system is provided for further research,and the accuracy is demonstrated by the aforementioned experiments.

关键词： seismic isolation acceleration-sensitive equipment the conical pendulum bearing shake table tests isolation performance,numerical model

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The fast method and convergence analysis of the fractional magnetohydrodynamic coupled flow and heat transfer model for the generalized second-grade fluid

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Science China Mathematics 2024年第4期67卷 919-950页

作者： Xiaoqing Chi hui Zhang Xiaoyun jiang School of Mathematics and Statistics Shandong UniversityWeihai 264209China School of Mathematics Shandong UniversityJinan 250100China

In this paper,we first establish a new fractional magnetohydrodynamic(MHD)coupled flow and heat transfer model for a generalized second-grade fluid.This coupled model consists of a fractional momentum equation and a heat conduction equation with a generalized form of Fourier law.The second-order fractional backward difference formula is applied to the temporal discretization and the Legendre spectral method is used for the spatial discretization.The fully discrete scheme is proved to be stable and convergent with an accuracy of O(τ^(2)+N-r),whereτis the time step-size and N is the polynomial degree.To reduce the memory requirements and computational cost,a fast method is developed,which is based on a globally uniform approximation of the trapezoidal rule for integrals on the real line.The strict convergence of the numerical scheme with this fast method is proved.We present the results of several numerical experiments to verify the effectiveness of the proposed method.Finally,we simulate the unsteady fractional MHD flow and heat transfer of the generalized second-grade fluid through a porous medium.The effects of the relevant parameters on the velocity and temperature are presented and analyzed in detail.

关键词： fractional MHD coupled flow and heat transfer model generalized second-grade fuid fast method convergence analysis numerical simulation

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Critical Role of Ethylene-Propylene Block Copolymer in Impact Polypropylene Copolymer

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Chinese Journal of Polymer Science 2024年第3期42卷 344-351,I0007页

作者： Yu-hui Tang Na Zhang Wei Bao Wei jiang Yuan Lin Zhao-hui Su State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Ethylene-propylene block copolymer(EbP) is a vital component in impact polypropylene copolymer(IPC), yet its distribution in the multiphase composite material and how it influences the phase structure and the mechanical properties are not well understood. In this work,four IPCs were investigated by atomic force microscopy-infrared(AFM-IR) to assess the phase compositions in situ, based on which in conjunction with the chain microstructure information obtained ex situ the distributions of the copolymer components were derived for each alloy. For the IPCs whose EbP comprises long P and long E segments, the EbP fraction was found to phase separate from the rubber and the PP matrix to form the cores of the disperse particles with the E-P segmented copolymer(EsP). In contrast, in the IPC with EbP composed of long P and short E segments, the EbP fraction formed an outer shell for the rubber particles with the cores comprising the EsP alone, and this IPC, containing a lower E comonomer content than its counterpart, exhibited both better impact resistance and higher flexural modulus. These results clarify how the chain structure of EbP governs the phase morphology in IPC, which in turn impacts the properties of the composite material.

关键词： Impact polypropylene copolymers AFM-IR Ethylene-propylene block copolymers Core-shell rubber particles

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Moderate Deviations for Parameter Estimation in the Fractional Ornstein–Uhlenbeck Processes with Periodic Mean

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1308-1324页

作者： hui jiang Shi Min LI Wei Gang WANG School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China The People's Bank of China Operations Ofice of Nanjing Branch Nanjing 210016P.R.China School of Statistics and Mathematics Zhejiang Gongshang UniversityHangzhou 310018P.R.China

In this paper,we study the asymptotic properties for the drift parameter estimators in the fractional Ornstein-Uhlenbeck process with periodic mean function and long range dependence.The Cremér-type moderate deviatio... 详细信息

关键词： Cramér-type moderate deviation fractional Ornstein-Uhlenbeck process parameter estimation multiple Wiener-Ito integrals

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A Reverse Path Planning Approach for Enhanced Performance of Multi-Degree-of-Freedom Industrial Manipulators

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1357-1379页

作者： Zhiwei Lin hui Wang Tianding Chen Yingtao jiang Jianmei jiang Yingpin Chen Key Laboratory of Light Field Manipulation and System Integration Applications in Fujian Province School of Physics and Information EngineeringMinnan Normal UniversityZhangzhou363000China Department of Electrical and Computer Engineering University of NevadaLas Vegas89154USA College of Material Engineering Fujian Agriculture and Forestry UniversityFuzhou350000China

In the domain of autonomous industrial manipulators,precise positioning and appropriate posture selection in path planning are pivotal for tasks involving obstacle avoidance,such as handling,heat sealing,and stacking.While Multi-Degree-of-Freedom(MDOF)manipulators offer kinematic redundancy,aiding in the derivation of optimal inverse kinematic solutions to meet position and posture requisites,their path planning entails intricate multiobjective optimization,encompassing path,posture,and joint motion optimization.Achieving satisfactory results in practical scenarios remains challenging.In response,this study introduces a novel Reverse Path Planning(RPP)methodology tailored for industrial manipulators.The approach commences by conceptualizing the manipulator’s end-effector as an agent within a reinforcement learning(RL)framework,wherein the state space,action set,and reward function are precisely defined to expedite the search for an initial collision-free path.To enhance convergence speed,the Q-learning algorithm in RL is augmented with Dyna-Q.Additionally,we formulate the cylindrical bounding box of the manipulator based on its Denavit-Hartenberg(DH)parameters and propose a swift collision detection technique.Furthermore,the motion performance of the end-effector is refined through a bidirectional search,and joint weighting coefficients are introduced to mitigate motion in high-power joints.The efficacy of the proposed RPP methodology is rigorously examined through extensive simulations conducted on a six-degree-of-freedom(6-DOF)manipulator encountering two distinct obstacle configurations and target positions.Experimental results substantiate that the RPP method adeptly orchestrates the computation of the shortest collision-free path while adhering to specific posture constraints at the target point.Moreover,itminimizes both posture angle deviations and joint motion,showcasing its prowess in enhancing the operational performance of MDOF industrial manipulators.

关键词： Reverse path planning Dyna-Q bidirectional search posture angle joint motion

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Acupuncture for obesity and related diseases:Insight for regulating neural circuit

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Journal of Integrative Medicine 2024年第2期22卷 93-101页

作者： Lin-yan jiang Jun Tian Ya-nan Yang Shao-hui Jia Qing Shu Department of Rehabilitation Medicine Zhongnan HospitalWuhan UniversityWuhan 430071Hubei ProvinceChina School of Sports Medicine Wuhan Sports UniversityWuhan 430079Hubei ProvinceChina Department of Traditional Chinese Medicine China Resources&Wu Gang General HospitalWuhan 430080Hubei ProvinceChina

Obesity is defined as abnormal or excessive fat accumulation that may impair health.Obesity is associated with numerous pathological changes including insulin resistance,fatty liver,hyperlipidemias,and other obesity-related diseases.These comorbidities comprise a significant public health threat.Existing anti-obesity drugs have been limited by side effects that include depression,suicidal thoughts,cardiovascular complications and stroke.Acupuncture treatment has been shown to be effective for treating obesity and obesity-related conditions,while avoiding side effects.However,the mechanisms of acupuncture in treating obesity-related diseases,especially its effect on neural circuits,are not well understood.A growing body of research has studied acupuncture’s effects on the endocrine system and other mechanisms related to the regulation of neural circuits.In this article,recent research that was relevant to the use of acupuncture to treat obesity and obesity-related diseases through the neuroendocrine system,as well as some neural circuits involved,was summarized.Based on this,acupuncture’s potential ability to regulate neural circuits and its mechanisms of action in the endocrine system were reviewed,leading to a deeper mechanistic understanding of acupuncture’s effects and providing insight and direction for future research about obesity.

关键词： Obesity Acupuncture Neural circuit Appetite Energy metabolism

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Development and validation of a new prognostic model for patients with acute-on-chronic liver failure in intensive care unit

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World Journal of Gastroenterology 2024年第20期30卷 2657-2676页

作者： Zong-Yi Zhu Xiu-Hong Huang hui-Qing jiang Li Liu Department of Gastroenterology The Second Hospital of Hebei Medical UniversityShijiazhuang 050000Hebei ProvinceChina Department of Gastroenterology Weixian People's HospitalXingtai 054700Hebei ProvinceChina

BACKGROUND Cirrhotic patients with acute-on-chronic liver failure(ACLF)in the intensive care unit(ICU)have a poor but variable prognoses.Accurate prognosis evaluation can guide the rational management of patients with ACLF.However,existing prognostic scores for ACLF in the ICU environment lack sufficient accuracy.AIM To develop a new prognostic model for patients with ACLF in ICU.METHODS Data from 938 ACLF patients in the Medical Information Mart for Intensive Care(MIMIC)database were used to develop a new prognostic model(MIMIC ACLF)for ACLF.Discrimination,calibration and clinical utility of MIMIC ACLF were assessed by area under receiver operating characteristic curve(AUROC),calibration curve and decision curve analysis(DCA),respectively.MIMIC ACLF was then externally validated in a multiple-center cohort,the Electronic Intensive Care Collaborative Research Database and a single-center cohort from the Second Hospital of Hebei Medical University in China.RESULTS The MIMIC ACLF score was determined using nine variables:ln(age)×2.2+ln(white blood cell count)×0.22-ln(mean arterial pressure)×2.7+respiratory failure×0.6+renal failure×0.51+cerebral failure×0.31+ln(total bilirubin)×0.44+ln(internationalized normal ratio)×0.59+ln(serum potassium)×0.59.In MIMIC cohort,the AUROC(0.81/0.79)for MIMIC ACLF for 28/90-day ACLF mortality were significantly greater than those of Chronic Liver Failure Consortium ACLF(0.76/0.74),Model for End-stage Liver Disease(MELD;0.73/0.71)and MELD-Na(0.72/0.70)(all P<0.001).The consistency between actual and predicted 28/90-day survival rates of patients according to MIMIC ACLF score was excellent and superior to that of existing scores.The net benefit of MIMIC ACLF was greater than that achieved using existing scores within the 50%threshold probability.The superior predictive accuracy and clinical utility of MIMIC ACLF were validated in the external cohorts.CONCLUSION We developed and validated a new prognostic model with satisfactory accuracy for cirrhotic patients with ACLF hospitalized in

关键词： Acute-on-chronic liver failure Cirrhosis Risk stratification Prognosis Model Scores

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