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An SPH Framework for Earthquake-Induced Liquefaction Hazard Assessment of geotechnical Structures

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 251-277页

作者： Sourabh Mhaski g.V.Ramana Department of civil Engineering Indian Institute of Technology DelhiNew Delhi110016India

Earthquake-induced soil liquefaction poses significant risks to the stability of geotechnical structures *** understanding of the liquefaction triggering,and the post-failure large deformation behaviour is essential for designing resilient *** present study develops a Smoothed Particle Hydrodynamics(SPH)framework for earthquake-induced liquefaction hazard assessment of geotechnical *** coupled flowdeformation behaviour of soils subjected to cyclic loading is described using the PM4Sand model implemented in a three-phase,single-layer SPH framework.A staggered discretisation scheme based on the stress particle SPH approach is adopted to minimise numerical inaccuracies caused by zero-energy modes and tensile ***,non-reflecting boundary conditions for seismic analysis of semi-infinite soil domains using the SPH method are *** numerical framework is employed for the analysis of cyclic direct simple shear test,seismic analysis of a level ground site,and liquefaction-induced failure of the Lower San Fernando *** agreement for liquefaction triggering and post-failure behaviour demonstrates that the SPH framework can be utilised to assess the effect of seismic loading on field-scale geotechnical *** present study also serves as the basis for future advancements of the SPH method for applications related to earthquake geotechnical engineering.

关键词： Earthquake seismic liquefaction stress particle PM4Sand smoothed particle hydrodynamics(SPH)

Cylinder Pressure Prediction of An HCci Engine Using Deep Learning

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Chinese Journal of Mechanical Engineering 2021年第2期34卷 160-167页

作者： Halit Yaşar gültekinÇağıl Orhan Torkul MerveŞişci Department of Mechanical Engineering Engineering FacultySakarya UniversityEsentepe Campus54187 SerdivanSakaryaTurkey Department of Industrial Engineering Engineering FacultySakarya UniversityEsentepe Campus54187 SerdivanSakaryaTurkey

Engine tests are both costly and time consuming in developing a new internal combustion ***,it is of great importance to predict engine characteristics with high accuracy using artificial ***,it is possible to reduce engine testing costs and speed up the engine development *** Learning is an effective artificial intelligence method that shows high performance in many research areas through its ability to learn high-level hidden features in data *** present paper describes a method to predict the cylinder pressure of a Homogeneous Charge Compression Ignition(HCci)engine for various excess air coefficients by using Deep Neural Network,which is one of the Deep Learning methods and is based on the Artificial Neural Network(ANN).The Deep Learning results were compared with the ANN and experimental *** results show that the difference between experimental and the Deep Neural Network(DNN)results were less than 1%.The best results were obtained by Deep Learning *** cylinder pressure was predicted with a maximum accuracy of 97.83%of the experimental value by using *** the other hand,the accuracy value was increased up to 99.84%using *** results show that the DNN method can be used effectively to predict cylinder pressures of internal combustion engines.

关键词： Artificial neural network Deep neural network HCci engine Cylinder pressure Excess air coefficient

Stepping up after spinal cord injury:negotiating an obstacle during walking

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Neural Regeneration Research 2025年第7期20卷 1919-1929页

作者： Alain Frigon Charly g.Lecomte Department of Pharmacology-Physiology Faculty of Medicine and Health SciencesUniversitéde SherbrookeCentre de recherche du Centre Hospitalier Universitaire de SherbrookeSherbrookeQCCanada

Every day walking consists of frequent voluntary modifications in the gait pattern to negotiate *** spinal cord injury,stepping over an obstacle becomes *** over an obstacle requires sensorimotor transformations in several structures of the brain,including the parietal cortex,premotor cortex,and motor *** information and planning are transformed into motor commands,which are sent from the motor cortex to spinal neuronal circuits to alter limb trajectory,coordinate the limbs,and maintain *** spinal cord injury,bidirectional communication between the brain and spinal cord is disrupted and animals,including humans,fail to voluntarily modify limb trajectory to step over an ***,in this review,we discuss the neuromechanical control of stepping over an obstacle,why it fails after spinal cord injury,and how it recovers to a certain extent.

关键词： biomechanics locomotion neurophysiology obstacle negotiation spinal cord injury

Secondary hardening behavior of 15CrMnMoV thin rolled tube

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Acta Metallurgica Sinica(English Letters) 2010年第4期23卷 261-266页

作者： ci DINg Weixin HAN Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

15CrMnMoV rolled tube is applied to many critical parts of helicopter. The secondary hardening behavior of the steel which varied with the treating process is essential for further usage. In this paper, the secondary hardening behavior of water quenched, oil quenched and air cooled steel are compared. The precipitations of alloy carbides are analyzed by electrolytic extraction, X-ray diffraction, optical microscopy as well as scanning electron microscopy. Results show that the secondary hardening effect in the air cooled steel is higher than in the water quenched and oil quenched steel, but the toughness decreases more seriously, due to more precipitation of Mo2C and VC.

关键词： 15CrMnMoV steel Secondary hardening Alloy carbides

A high precision model for the terminal settling velocity of drops in fluid medium

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Frontiers of Earth Science 2021年第4期15卷 947-955页

作者： Qiu YIN ci SONg Shanghai Meteorological Service China Meteorological AdministrationShanghai 200030China College of Science Zhongyuan University of TechnologyZhengzhou 450007China School of Communication and Information Engineering Shanghai UniversityShanghai 200444China

The terminal settling velocity(TSV)calcula-tion of drops and other spherical objects in fluid medium is a classical problem,which has important application values in many fields such as the study of cloud and precipitation processes,the evaluation of soil erosion,and the determination of fluid viscosity coefficient *** this paper,a new explicit approximation model of TSV is established,which combines the theoretical solution of N-S equation about fluid motion around spherical objects and the statistical regression of solution dimensionless coeffi-cients with measurement *** new model can adapt to different values of drop parameters and medium parameters in a large range of *** this model,the relative and absolute calculation errors of TSV are in range of 3.42%+4.34%and 0.271 m/s-+0.128 m/s respec-tively for drop radius 0.005-2.9 *** corresponding root mean square values are 1.77%and 0.084 rn/s respectively,which are much smaller than that of past theoretical and empirical models.

关键词： terminal settling velocity drag coefficient viscous resistance drop fluid medium

Research on vertical spatial characteristic of satellite infrared hyperspectral atmospheric sounding data

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Frontiers of Earth Science 2022年第2期16卷 265-276页

作者： ci SONg Qiu YIN School of Communication and Information Engineering Shanghai UniversityShanghai 200444China College of Science Zhongyuan University of TechnologyZhengzhou 450007China Shanghai Meteorological Service Shanghai 200030China User Office of Meteorological Satellites China Meteorological AdministrationShanghai 200030China

Spatial characteristic is an important indicator of remote sensor performance,and space-borne infrared hyperspectral sounder is the frontier of atmospheric vertical sounding *** this paper,the formation mechanism of the vertical spatial characteristics involved in the space-borne infrared hyperspectral sounding data are analyzed in detail,which shows that the vertical spatial characteristics of sounding data depends not only on the spectral channels and their waveband coverage,but also the specific atmospheric parameter and its specific variation *** indicators of vertical spatial characteristics are defined and their mathematical models are established based on the mechanism *** models are applied to the vertical spatial characteristic evaluation of atmospheric temperature sounding for FY-4A gIIRS,which is the first space-borne infrared hyperspectral atmospheric sounder in geostationary *** is concluded that FY-4A gIIRS can sound the vertical temperature distribution in whole troposphere and lower stratosphere with height<35 *** study can provide basic information to support the improvement of infrared hyperspectral sounder and the trace of vertical spatial characteristics of atmospheric inversion products.

关键词： infrared hyperspectral atmospheric sounding vertical spatial characteristic atmospheric temperature FY-4A gIIRS

CONSTRAINED QUADRILATERAL NONCONFORMINg ROTATED Q1 ELEMENT

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Journal of Computational Mathematics 2005年第6期23卷 561-586页

作者： Jun Hu Zhong-ci Shi LSEC ICMSEC Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China

In this paper, we define a new nonconforming quadrilateral finite element based on the nonconforming rotated Q1 element by enforcing a constraint on each element, which has only three degrees of freedom. We investigate the consistency, approximation, superclose property, discrete green＇s function and superconvergence of this element. Moreover, we propose a new postprocessing technique and apply it to this element. It is proved that the postprocessed discrete solution is superconvergent under a mild assumption on the mesh.

关键词： Constrained Nonconforming Rotated Q1 element Superconvergence Postprocess

Simulation study on heat-affected zone of high-strain X80 pipeline steel

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Journal of Iron and Steel Research International 2017年第9期24卷 966-972页

作者： Ying ci Zhan-zhan Zhang College of Information Science and Engineering Northeastern University School of Physical Science and Engineering Zhengzhou University

The microstructure evolution and impact-toughness variation of heat-affected zone（HAZ）in X80 highstrain pipeline steel were investigated via a welding thermal-simulation technique,Charpy impact tests,and scanning electron microscopy observations under different welding heat inputs and peak *** results indicate that when heat input was between 17 and 25kJ·cm^（-1）,the coarse-grained heat-affected zone showed improved impact *** the heat input was increased further,the martensite-austenite（M-A）islands transformed from fine lath into a massive ***,impact toughness was substantially *** the heat input was 20kJ·cm^（-1） and the peak temperature of the first thermal cycle was between 900 and 1300°C,a higher impact toughness was *** heat input was 20kJ·cm^（-1） and the peak temperature of the first thermal cycle was 1300°C,the impact toughness value at the second peak temperature of 900°C was higher than that at the second peak temperature of 800°C because of grain refining and uniformly dispersed M-A constituents in the matrix of bainite.

关键词： High-strain X80 pipeline steel Welding heat input Peak temperature Impact toughness Microstructure

脱细胞皮肤基质/聚氨酯混纺纤维支架促进大鼠皮肤缺损的修复

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中国组织工程研究 2025年第4期29卷 745-751页

作者：吴辰江佳慧苏豆刘晨慈超皖南医学院第一附属医院皮肤性病科安徽省芜湖市241001 皖南医学院第一附属医院脊柱外科安徽省芜湖市241001

背景:研究证实,将脱细胞基质与聚合物进行混合纺丝不仅可改善纤维的结构性质,还可保存脱细胞基质的生物学活性,但是目前将聚氨酯与脱细胞皮肤基质进行静电纺丝制备皮肤组织工程支架还没有相关报道。目的:观察脱细胞皮肤基质/聚氨酯混纺... 详细信息

背景:研究证实,将脱细胞基质与聚合物进行混合纺丝不仅可改善纤维的结构性质,还可保存脱细胞基质的生物学活性,但是目前将聚氨酯与脱细胞皮肤基质进行静电纺丝制备皮肤组织工程支架还没有相关报道。目的:观察脱细胞皮肤基质/聚氨酯混纺纤维支架对大鼠皮肤缺损的修复作用。方法:利用静电纺丝技术分别制备聚氨酯静电纺丝纤维支架和脱细胞皮肤基质/聚氨酯混纺纤维支架。扫描电镜下观察纤维结构;将大鼠脂肪间充质干细胞分别接种于两组支架上,扫描电镜下观察支架上的细胞形态。取10只SD大鼠,在每只大鼠背部制作3个1 cm×1 cm的全层皮肤缺损,其中2处缺损分别植入聚氨酯静电纺丝纤维支架(对照组)、脱细胞皮肤基质/聚氨酯混纺纤维支架(实验组),剩余缺损处不植入任何材料(空白对照组)。术后第1,2,3周,观察皮肤创面愈合情况;植入后第3周,进行创面苏木精-伊红染色,计算创面瘢痕面积。结果与结论:①扫描电镜下可见两种静电纺丝纤维均为网状结构,并且大鼠脂肪间充质干细胞在两种支架上沿纤维附着,黏附良好。②随着术后时间的延长,各组皮肤创面逐渐愈合,至术后第3周,实验组、对照组皮肤创面基本愈合,空白对照组创面可见小溃疡形成。皮肤创面苏木精-伊红染色显示,对照组、实验组创面表皮覆盖基本完整,真皮层内可见成纤维细胞长入和炎症细胞浸润,并且实验组创面胶原纤维较为丰富、排列规则有序,与表皮面基本平行;空白对照组创面表皮仍有缺损。实验组创面瘢痕面积小于其他两组(P<0.05,P<0.01)。③结果表明,脱细胞皮肤基质/聚氨酯混纺纤维支架可以有效修复大鼠全层皮肤缺损、改善创面瘢痕形成。

关键词：脱细胞皮肤基质聚氨酯静电纺丝皮肤缺损瘢痕