检索结果-南通市图书馆

Extreme Wave Simulation with Iterative Adaptive Approach in Numerical Wave Flume

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2021年第1期35卷 61-71页

作者： liu Dian-yong Naval Architecture and Ocean Engineering College Dalian Maritime UniversityDalian 116026China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116023China

Extreme wave is highly nonlinear and may occur due to diverse reasons *** simulated results of extreme wave based on wave focusing,which were generated using high order spectrum method,are *** influences of the steepness,frequency bandwidth as well as frequency spectrum on focusing position shift were examined,showing that they can affect the wave focusing ***,controlled accurate generation of extreme wave at a predefined position in wave flume is a difficult but important *** this paper,an iterative adaptive approach is applied using linear dispersion theory to optimize the control signal of the *** performance of the proposed approach is numerically investigated for a wide variety of *** results demonstrate that this approach can reproduce accurate wave focusing effectively.

关键词： extreme wave wave focusing numerical wave flume iterative adaptive approach

Algorithm design and the development of a discrete element method for simulating particulate flow and heat transfer

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2021年第2期5卷 141-166页

作者： bing liu National Institute of Clean-and-Low-Carbon Energy CHN Energy InvestmentBeijing 102211P.R.China

An algorithm using the discrete element method(DEM)for simulating the particulate behaviour of flow and heat transfer is developed and described,the reasonable hypothesis and the ingenious design of which have been presented in *** organizational structure of the developed algorithm contains an efficient method for determining particle collisions,the status analysis for each particle and the particulate-kinematics analysis during the time *** reasonability and correctness of the developed DEM algorithm are validated by laboratory experiments:the discharge process of glass beads from a silo;and heating of metal alloy particles in a ***,a group of validated mechanics parameter values for coal and sand have been tested and verified in the article,preparing for the simulation of the pyrolysis process in a downer or screw reactor in subsequent research projects.

关键词： DEM algorithm particulate flow solid mechanics heat-transfer model

Structural optimization of baffle internals for fast particle pyrolysis in a downer reactor using the discrete element method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clean Energy 2021年第2期5卷 167-179页

作者： bing liu National Institute of Clean-and-Low-Carbon Energy CHN Energy InvestmentBeijing 102211P.R.China

The structural optimization of baffle internals for fast pyrolysis of coal with particulate mixing and heat transfer in a downer reactor using the discrete element method(DEM)has been investigated in this *** pyrolysis terminal temperature at the exit of the downer reactor is not only decided by the volume-feeding-rate ratio of the coal to the sand,but also is affected by the inner structural design of the baffle internals in the downer *** presented in the previous publication of the author,the inhibition from the baffle internals in a downer reactor can improve the particulate-mixing degree and heat carrier,and increase the mean residence time of the coal and heat-carrier particles in the downer *** structure of the baffle internals in the downer reactor mentioned in this research can be optimized by the independently developed 3D soft-sphere model of the DEM programme of a 40-mm baffle length,a 30°baffle-slope angle and at least four baffles designed in the downer reactor,which is beneficial for the process design of coal pyrolysis with a heat carrier in the downer reactor.

关键词： structural optimization baffle internals downer reactor DEM coal pyrolysis

Effects of Sc and Zr microalloying on the microstructure and mechanical properties of high Cu content 7xxx Al alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1559-1569页

作者： Chong-yu liu Guang-biao Teng Zong-yi Ma Li-li Wei bing Zhang yong Chen College of Material Science and Engineering Guilin University of TechnologyGuilin 541004China Guangdong JMA Aluminum Profile Factory(Group)Co. Ltd.Foshan 528200China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

The effects of Sc and Zr microalloying on the microstructure and mechanical properties of a 7xxx Al alloy with high Cu content(7055)during casting,deformation,and heat treatment were *** addition of Sc and Zr not only refined the grains but also transformed theθ-phase into the W-phase in the 7055 *** Sc and Zr additions enhanced the hardness and yield strength of the 7055-T6 alloy by strengthening the grain boundaries and Al3(Sc,Zr)***,a further increase in the Sc and Zr fractions did not refine the grains but instead resulted in the formation of the large-sized W-phase and primary coarse Al3(Sc,Zr)phase and subsequently deteriorated the mechanical properties of the *** 7055 alloy with 0.25Sc addition exhibited the best mechanical property among the prepared alloys.

关键词： aluminum alloys microstructural evolution mechanical property grain refinement

基于轻量化卷积神经网络的桥梁斜拉索PE护套损伤识别方法

在线全文

学校读者我要写书评

暂无评论

土木与环境工程学报（中英文） 2025年第1期47卷 167-178页

作者：刘啸宇黄永徐峰李惠上海交通大学船舶海洋与建筑工程学院上海200240 哈尔滨工业大学土木工程学院哈尔滨150090

深度神经网络和计算机视觉技术近年来在结构健康监测中发挥了越来越重要的作用。利用无人机航拍采集的桥梁斜拉索损伤图像数据,研究基于深度学习技术的斜拉索PE护套损伤识别方法。为实现在较低运算能力设备上对大跨度桥梁斜拉索表面局... 详细信息

深度神经网络和计算机视觉技术近年来在结构健康监测中发挥了越来越重要的作用。利用无人机航拍采集的桥梁斜拉索损伤图像数据,研究基于深度学习技术的斜拉索PE护套损伤识别方法。为实现在较低运算能力设备上对大跨度桥梁斜拉索表面局部损伤的智能快速识别,解决传统深度卷积神经网络的运算效率相对较低、模型参数规模较大的问题,提出轻量化处理的区域推荐型卷积神经网络模型。介绍区域推荐网络与其轻量化改进方法的理论基础,分析轻量化模型处理的必要性,其能在保证识别精度的前提下降低模型训练与预测的设备性能需求,达到节约计算资源与时间的目的;通过数据增广等多手段解决损伤样本数据量不足的问题,设置对比试验,统计分析结果,验证了轻量化神经网络模型的优越性。结果表明,轻量化网络在牺牲少量识别准确度的前提下,能够在较大程度上实现对模型复杂度与计算量的改进,在工程应用中能有效拓展神经网络的实用性。

关键词：桥梁斜拉索智能损伤识别轻量化神经网络计算机视觉深度学习

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Toric Rigid Spaces

Acta Mathematica Sinica,English Series 2007年第9期23卷 1621-1628页

作者： bing yong HSIE Zhi Bin LIANG LMAM Department of Mathematics Peking University Beijing 100871 P. R. China

This paper gives a method to construct rigid spaces, which is similar to the method used to construct toric schemes.

关键词： cone fan strongly convex rational polyhedral cone toric affinoid algebra toric rigid space toric scheme

The siltation of debris flow behind check dam in the midstream of Bailong River

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2018年第1期15卷 100-113页

作者： YUAN Dong liu Jin-feng YOU yong liu Dao-chuan SUN Hao ZHANG Li ZHOU Wen-bing Key Laboratory of Mountain Hazards and Earth Surface Process CAS Chengdu 610041 China Institute of Mountain Hazards and Environment CAS Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China

Siltation gradient and siltation length are important parameters for designing gravity check dams for debris flows,which directly affect the accuracy of estimates of interception *** present,siltation gradient calculations are based primarily on empirical values,and range from 0.4 to 0.95 times the channel slope *** middle reaches of the Bailong River are one of the four areas in China that are most severely affected by debris flow *** dams are widely employed in this mountainous ***,field studies of their capacity are *** this paper,the operations of check dams were *** on field investigation results and theoretical analysis,calculations for siltation gradient,siltation length,and dam storage capacity are *** impact of debris flow density,channel slope,and particle size weight percentages are *** calculations show that the theoretical values for siltation gradient are consistent with measured values with 83.6% accuracy;and theoretical values of siltation length are consistent with measured values with 91.6% *** results of this research are an important reference for optimal height and spacing of dams,estimation of dam storage capacity,and disaster prevention.

关键词： Debris flow Check dam Siltation gradient Siltation length Disaster prevention engineering

Influence of Magnetic Scattering and Interface Transparency on Superconductivity Based on a Ferromagnet/Superconductor Heterostructure

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第8期28卷 281-284页

作者： PENG Lin liu yong-Sheng CAI Chuan-bing ZHANG Jin-Cang Department of Physics Shanghai University of Electric PowerShanghai 200090 Department of Physics Shanghai UniversityShanghai 200444

We investigate an antiferromagnet/ferromagnet/superconductor/ferromagnet(AF/F/S/F)spin-valve system with nanoscopic scale,described by Usadel equations in the dirty *** results show that the superconducting characteristics in the system strongly depend not only on the mutual orientation and thickness of two ferromagnetic layers,but also on the interface transparency and the magnetic *** superconducting critical temperature can exhibit three types of characteristic behaviors with a variation of interface *** particular,the reentrance phenomenon of the superconductivity is observed at the interface transparencyγBξn/ξf=7.1,while the reentrance phenomenon disappears in the presence of magnetic *** addition,it is also found that the introduction of magnetic scattering results in the decrease of the spin-valve *** obtained results could provide some practical recommendations for the spin-valve effect in experimental observation.

关键词： transparency interface mutual

Molecular Dynamics Simulation of Microstructure Transitions in a Large-Scale Liquid Metal Al System During Rapid Cooling Processes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2002年第8期19卷 1144-1147页

作者： liu Rang-Su Dong Ke-Jun Li Ji-yong Yu Ai-bing Zou Rui-Ping Department of Physics Hu'nan University Changsha 410082 School of Materials Science and Engineering The University of New South Wales Sydney New South Wales 2052 Australia Department of Chemistry Hu'nan University Changsha 410082

We perform a molecular dynamics simulation of microstructure transitions in a large-scale system consisting of 400000 atoms of liquid metal Al by the Clare supercomputer. A cluster-type index method is proposed to describe the structures of various short-range-order clusters in the liquid system. It is demonstrated that the icosahedron cluster (12 0 12 0) plays the most important role in the microstructure transition and that some larger clusters (containing more than 130 atoms) are formed in the system during the rapid cooling processes. It is obvious that the larger clusters are formed by means of combining some middle clusters, and that the middle clusters are formed with several smaller clusters. However, the larger clusters are not formed to be the multi-shell configuration as shown in the mass spectrum analysis of the cluster configurations of Al obtained by gaseous deposition, ionic spray methods and so on. This result can be used to explain the essential distinction between the cluster configurations of Al formed in two different ways.

关键词： Molecular dynamics