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InSAR 1

地球同步SAR 1

数字高程模型（DEM） 1

每日DEM生成 1

等流时线 1

精度分析 1

设计洪水 1

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基于DEM的资料短缺地区设计洪水推求

张婷,冯平

《中国工程科学》 2011年第13卷第12期页码 68-73

摘要：

以缺少径流资料的福州市北部山区流域为例，通过数字高程模型（DEM）技术与新安江三水源模型相结合的方法，探讨了资料短缺地区设计洪水的计算方法在汇流计算中，通过DEM推求等流时线，避免了在地图上勾绘等流时线的繁琐工作。随着全国各地数字高程模型的建立，将其运用到水文计算当中有重要的现实意义。

关键词：资料短缺地区设计洪水数字高程模型（DEM）等流时线

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利用地球同步轨道InSAR每日生成DEM的质量分析 Article

杨泽发, 张庆君, 丁晓利, 陈武

《工程（英文）》 2020年第6卷第8期页码 913-918 doi: 10.1016/j.eng.2020.07.003

摘要：

最新的数字高程模型（DEM）产品在灾害防治、城市管理等诸多领域中扮演着重要角色。利用机载或低地球轨道（LEO）的星载干涉合成孔径雷达（InSAR）生成DEM已被证明是可行且极具价值的方法。然而，受成本和卫星重返周期的限制，该技术难以频繁（如每天）生成或更新大区域范围（如大陆尺度或更大范围）的DEM。由于对地同步合成孔径雷达（GEOSAR）卫星运行于地球静止轨道，因此它们能以相当短的重返时间（每天或更短）观测同一地面区域，这为实现生成每日DEM这一理想但目前难以实现的目标提供了潜在可能。为此，本文系统地分析了利用GEOSAR卫星生成的每日DEM产品质量。结果表明：GEOSAR卫星生成的每日DEM产品精度通常远低于利用传统低轨星载合成孔径雷达（SAR）获得的DEM产品。因此，研究GEOSAR DEM生成过程中的误差削弱方法显得至关重要。

关键词：每日DEM生成 InSAR 地球同步SAR 精度分析

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Multiscale mechanical modeling of hydrated cement paste under tensile load using the combined DEM-MD

Yue HOU, Linbing WANG

《结构与土木工程前沿（英文）》 2017年第11卷第3期页码 270-278 doi: 10.1007/s11709-017-0408-8

摘要： In this paper, a combined DEM-MD method is proposed to simulate the crack failure process of Hydrated Cement Paste (HCP) under a tensile force. A three-dimensional (3D) multiscale mechanical model is established using the combined Discrete Element Method (DEM)-Molecular Dynamics (MD) method in LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). In the 3D model, HCP consists of discrete particles and atoms. Simulation results show that the combined DEM-MD model is computationally efficient with good accuracy in predicting tensile failures of HCP.

关键词： hydrated cement paste multiscale MD simulation DEM

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Magnetic-porous microspheres with synergistic catalytic activity of small-sized gold nanoparticles and titania matrix

Kadriye Özlem Hamaloğlu, Ebru Sağ, Çiğdem Kip, Erhan Şenlik, Berna Saraço

《化学科学与工程前沿（英文）》 2019年第13卷第3期页码 574-585 doi: 10.1007/s11705-019-1799-y

摘要： Fe O nanoparticles immobilized on porous titania in micron-size range were decorated with small-sized gold nanoparticles and used as a plasmonic catalyst for the reduction of 4-nitrophenol. Monodisperse-porous magnetic titania microspheres were synthesized with bimodal pore-size distribution by the sol-gel templating method. Small-sized gold nanoparticles obtained by the Martin method were attached onto the aminated form of the magnetic titania microspheres. A significant enhancement in the catalytic activity was observed using the gold nanoparticle-decorated magnetic titania microspheres compared to gold nanoparticle-decorated magnetic silica microspheres because of the synergistic effect between small-sized gold nanoparticles and titania. The synergistic effect for gold nanoparticle-attached magnetic titania microspheres could be explained by surface plasmon resonance-induced transfer of hot electrons from gold nanoparticles to the conduction band of titania. Using the proposed catalyst, 4-nitrophenol could be converted to 4-aminophenol in an aqueous solution within 0.5 min. The 4-nitrophenol reduction rates were 2.5–79.3 times higher than those obtained with similar plasmonic catalysts. The selection of micron-size, magnetic, and porous titania microspheres as a support material for the immobilization of small-sized gold nanoparticles provided a recoverable plasmonic catalyst with high reduction ability.

关键词： small-sized gold nanoparticles magnetic titania microspheres sol-gel template synthesis plasmonic catalysis 4-nitrophenol

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Design and analyses of open-ended pipe piles in cohesionless soils

Yuan GUO,Xiong (Bill) YU

《结构与土木工程前沿（英文）》 2016年第10卷第1期页码 22-29 doi: 10.1007/s11709-016-0314-5

摘要： Large open-ended pipe pile has been found to be advantageous for use in transportation projects. The current design method, however, is not adequately developed. To close this practice gap, this paper first summarized different design methods for open-ended pipe piles in sandy soils. A major factor for all the design codes is to properly account for the formation and effects of soil plug. The comparison indicates that there is a large variation in the base capacity evaluation among different methods due to the complex behaviors of soil plug. To close the knowledge gap, discrete element method (DEM) was used to simulate the soil plugging process and provide insight on the plugging mechanism. The simulation results show that the arching effect significantly increases the internal unit shear resistance along pipe piles. The porosity distribution and particle contact force distribution from DEM model indicate a large stress concentration occurs at the bottom of the soil plug. Besides, nearly 90% of the plug resistance is provided by the bottom half portion of the soil column. The soil-pile friction coefficient has a significant effect on the magnitude of plug resistance, with the major transition occurred for friction coefficient between 0.3 and 0.4.

关键词： open-ended pipe pile soil plug DEM base capacity

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On the applicability of different adhesion models in adhesive particulate flows

Guanqing LIU, Shuiqing LI, Qiang YAO,

《能源前沿（英文）》 2010年第4卷第2期页码 280-286 doi: 10.1007/s11708-009-0062-5

摘要： An adhesion map provides quantitative criteria for the appropriate selection of adhesion models applicable to a specific adhesive contact problem of fine particles in complex particulate flows. In this paper, three different general adhesion models are used to construct adhesion maps. The applicable regimes on the adhesion map for different approximate adhesion models are determined according to their underlying limitations. It is found that the choice of general model has limited influence on the structure of a constructed adhesion map. On the contrary, the regime of application for each approximate model is sensitive to the approximation level. A three-dimensional, more intuitive adhesion map based on physical parameters of particles is also built. Finally, recent applications of adhesion models in discrete element method (DEM) investigations of fine-particle flow dynamics are briefly discussed.

关键词： adhesive contact van der Waals force adhesion model adhesion map DEM

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Strain localization analyses of idealized sands in biaxial tests by distinct element method

Mingjing JIANG, Hehua ZHU, Xiumei LI,

《结构与土木工程前沿（英文）》 2010年第4卷第2期页码 208-222 doi: 10.1007/s11709-010-0025-2

摘要： This paper presents a numerical investigation on the strain localization of an idealized sand in biaxial compression tests using the distinct element method (DEM). In addition to the dilatancy and material frictional angle, the principal stress field, and distributions of void ratio, particle velocity, and the averaged pure rotation rate (APR) in the DEM specimen are examined to illustrate the link between microscopic and macroscopic variables in the case of strain localization. The study shows that strain localization of the granular material in the tests proceeds with localizations of void ratio, strain and APR, and distortions of stress field and force chains. In addition, both thickness and inclination of the shear band change with the increasing of axial strain, with the former valued around 10–14 times of mean grain diameter and the later overall described by the Mohr-Coulomb theory.

关键词： idealized sand strain localization numerical analyses distinct element method (DEM)

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Influence mechanism of dynamic and static liquid bridge forces on particle deposition behaviors in solar photovoltaic mirrors

Xueqing LIU, Xiaodong ZHAO, Luyi LU, Jianlan LI

《能源前沿（英文）》 2021年第15卷第2期页码 499-512 doi: 10.1007/s11708-021-0742-3

摘要： Solar energy is one of the most promising forms of renewable energy for solving the energy crisis and environmental problems. Dust deposition on photovoltaic mirrors has a serious negative impact on the photoelectric conversion efficiency of solar power stations. In this paper, the influence mechanism of the dynamic and static liquid bridge forces on particle deposition behaviors on solar photovoltaic mirrors is investigated. In addition, the expression and physical meaning of the particle critical separation velocity are proposed. The research results show that the static liquid bridge force can be the primary deposition force causing dust particles to adhere to photovoltaic mirrors. However, the dynamic liquid bridge force can act as a resistance force for the particle motion process and even make dust particles roll along and finally stay on the mirror. The contact force is the primary separation force that causes dust particles to flow away from the mirror. Whether dust particles adhere to the mirror depends on the relative size of the deposition and separating forces. The particle critical separation velocity describes the relative size of the collision-rebound effect and mirror adhesion effect and is expressed in Eq. (16). These research findings can provide theoretical guidance for mirror cleaning methods in the operation process of photovoltaic mirrors.

关键词： dust deposition discrete element method (DEM) photovoltaic mirrors solar energy

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Numerical simulation of two-dimensional spouted bed with draft plates by discrete element method

ZHAO Yongzhi, JIANG Maoqiang, CHENG Yi, JIN Yong

《化学科学与工程前沿（英文）》 2008年第2卷第1期页码 5-9 doi: 10.1007/s11705-008-0009-0

摘要： A discrete element method (DEM)-computational fluid dynamics (CFD) two-way coupling method was employed to simulate the hydrodynamics in a two-dimensional spouted bed with draft plates. The motion of particles was modeled by the DEM and the gas flow was modeled by the Navier-Stokes equation. The interactions between gas and particles were considered using a two-way coupling method. The motion of particles in the spouted bed with complex geometry was solved by combining DEM and boundary element method (BEM). The minimal spouted velocity was obtained by the BEM-DEM-CFD simulation and the variation of the flow pattern in the bed with different superficial gas velocity was studied. The relationship between the pressure drop of the spouted bed and the superficial gas velocity was achieved from the simulations. The radial profile of the averaged vertical velocities of particles and the profile of the averaged void fraction in the spout and the annulus were statistically analyzed. The flow characteristics of the gas-solid system in the two-dimensional spouted bed were clearly described by the simulation results.

关键词： annulus BEM-DEM-CFD simulation gas-solid two-dimensional relationship

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Discrete element method modeling of corn-shaped particle flow in rectangular hopper

He TAO, Baosheng JIN, Wenqi ZHONG, Xiaofang WANG,

《结构与土木工程前沿（英文）》 2010年第4卷第2期页码 267-275 doi: 10.1007/s11709-010-0035-0

摘要： Discrete element method (DEM) was developed to simulate the corn-shaped particles flow in the hopper. The corn-shaped particle was described by four overlapping spheres. Contact force and gravity force were considered when establishing the model. In addition, flowing characteristic of particles in the hopper was studied. The effect of friction coefficient on the wall pressure, voidage and velocity distribution was analyzed. The results show that the discharge rate decreases with the friction coefficient increasing; and the “over-pressure” phenomenon occurs in the discharging process for two different friction coefficients. The voidage also increases as the friction coefficient increasing. And the velocity distribution is more uniformity and is closer to the mass flow with the friction coefficient deceasing.

关键词： discrete  element   method  (DEM)   non-spherical voidage pressure velocity distribution hopper