检索结果-南通市图书馆

Rock fracture mechanism of buffer blasting with cushion layer at the borehole bottom

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 325-334页

作者： Xinguang Zhu Chenxi Ding Zhe Sui Hong Su Xu Guo School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China Key laboratory for mechanics in fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

This study primarily investigates the rock fracture mechanism of bottom cushion layer blasting and explores the effects of the bottom cushion layer on rock *** involves analyses of the evolution patterns of blasting stress,characteristics of crack distribution,and rock fracture features in the ***,blasting model experiments were carried out using the dynamic caustics principle to investigate the influence of bottom cushion layers and initiation methods on the integrity of the bottom rock *** experimental results indicate that the combined use of bottom cushion layers and inverse initiation effectively protects the integrity of the bottom rock ***,the process of stress wave propagation and dynamic crack propagation in rocks was simulated using the continuum-discontinuum element method(CDEM)and the Landau explosion source model,with varying thicknesses of bottom cushion *** numerical simulation results indicate that with increasing cushion thickness,the absorption of energy generated by the explosion becomes more pronounced,resulting in fewer cracks in the bottom rock *** illustrates the positive role of the cushion layer in protecting the integrity of the bottom rock mass.

关键词： bottom cushion layer blasting crack propagation continuum-discontinuum element method dynamic stress intensity factor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Painlevé analysis, auto-Bäcklund transformations, bilinear forms and soliton solutions for a(2+1)-dimensional variable-coefficient modified dispersive water-wave system in fluid mechanics

引用

Communications in Theoretical Physics 2023年第2期75卷 46-55页

作者： Fei-Yan Liu Yi-Tian Gao Ministry-of-Education Key laboratory of fluid mechanics and National laboratory for Computational fluid Dynamics Beijing University of Aeronautics and AstronauticsBeijing 100191China

In this paper,we investigate a(2+1)-dimensional variable-coefficient modified dispersive waterwave system in fluid *** prove the Painlevéintegrability for that system via the Painlevé*** find some auto-B?cklund transformations for that system via the truncated Painlevé*** forms and N-soliton solutions are constructed,where N is a positive *** discuss the inelastic interactions,elastic interactions and soliton resonances for the two *** also graphically demonstrate that the velocities of the solitons are affected by the variable coefficient of that system.

关键词： fluid mechanics variable-coefficient modified dispersive water-wave system Painlevéanalysis bilinear forms soliton solutions auto-Bäcklund transformations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Bell-Polynomial Approach and Soliton Solutions for Some Higher-Order Korteweg-de Vries Equations in fluid mechanics,Plasma Physics and Lattice Dynamics

引用

Communications in Theoretical Physics 2015年第12期64卷 630-636页

作者：李鹤高以天刘立才 Ministry-of-Education Key laboratory of fluid mechanics and National laboratory for Computational fluid Dynamics Beijing University of Aeronautics and Astronautics State Key laboratory of Information Photonics and Optical Communications and School of ScienceBeijing University of Posts and Telecommunications

The Korteweg-de Vries(Kd V)-type equations have been seen in fluid mechanics,plasma physics and lattice dynamics,etc. This paper will address the bilinearization problem for some higher-order Kd V equations. Based on the relationship between the bilinear method and Bell-polynomial scheme,with introducing an auxiliary independent variable,we will present the general bilinear forms. By virtue of the symbolic computation,one-and two-soliton solutions are derived.

关键词： Korteweg-de Vries-type equations Bell-polynomial a

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Darboux Transformation and Soliton Solutions for a Variable-Coefficient Modified Kortweg-de Vries Model from fluid mechanics, Ocean Dynamics, and Plasma mechanics

引用

Communications in Theoretical Physics 2010年第4期53卷 673-678页

作者：盖晓玲高以天孟得新王雷孙志远吕兴冯茜王明振于鑫朱顺辉 Ministry-of-Education Key laboratory of fluid mechanics and National laboratory for Computational fluid Dynamics Beijing University of Aeronautics and Astronautics State Key laboratory of Software Development Environment Beijing University of Aeronautics and Astronautics School of Science Beijing University of Posts and Telecommunications

This paper is to investigate a variable-coefficient modified Kortweg-de Vries （vc-mKdV） model, which describes some situations from fluid mechanics, ocean dynamics, and plasma mechanics. By the AblowRz-Kaup-NewellSegur procedure and symbolic computation, the Lax pair of the vc-MKdV model is derived. Then, based on the aforementioned Lax pair, the Darboux transformation is constructed and a new one-soliton-like solution is obtained as weft Features of the one-soliton-like solution are analyzed and graphically discussed to illustrate the influence of the variable coefficients in the solitonlike propagation.

关键词： variable-coefficient modified Kortweg-de Vries model, Lax pair, Darboux trans brmation, soliton solutions

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Integrable Hierarchy Covering the Lattice Burgers Equation in fluid mechanics:N-fold Darboux Transformation and Conservation Laws

引用

Communications in Theoretical Physics 2012年第9期58卷 323-330页

作者：闻小永高以天薛玉山郭睿齐凤华于鑫 State Key laboratory of Software Development Environment Beijing University of Aeronautics and Astronautics Department of Mathematics School of SciencesBeijing Information Science and Technology University Ministry-of-Education Key laboratory of fluid mechanics and National laboratory for Computational fluid Dynamics Beijing University of Aeronautics and Astronautics School of Science P.O.Box 122Beijing University of Posts and Telecommunications

Burgers-type equations can describe some phenomena in fluids,plasmas,gas dynamics,traffic,*** this paper,an integrable hierarchy covering the lattice Burgers equation is derived from a discrete spectral problem.N-fold Darboux transformation(DT) and conservation laws for the lattice Burgers equation are constructed based on its Lax pair.N-soliton solutions in the form of Vandermonde-like determinant are derived via the resulting DT with symbolic computation,structures of which are shown *** of the elastic-inelastic interaction among the three solitons is firstly reported for the lattice Burgers equation,even if the similar phenomenon for certern continuous systems is *** in this paper might be helpful for understanding some ecological problems describing the evolution of competing species and the propagation of nonlinear waves in fluids.

关键词： discrete spectral problem lattice Burgers equation N-fold Darboux transformation conservationlaws symbolic computation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Painlevé Analysis,Soliton Solutions and Bcklund Transformation for Extended (2 + 1)-Dimensional Konopelchenko-Dubrovsky Equations in fluid mechanics via Symbolic Computation

引用

Communications in Theoretical Physics 2011年第6期55卷 1017-1023页

作者：许鹏博高以天于鑫王雷林国栋 Ministry-of-Education Key laboratory of fluid mechanics and National laboratory for Computational fluid Dynamics Beijing University of Aeronautics and Astronautics State Key laboratory of Software Development Environment Beijing University of Aeronautics and Astronautics

This paper is to investigate the extended(2+1)-dimensional Konopelchenko-Dubrovsky equations,which can be applied to describing certain phenomena in the stratified shear flow,the internal and shallow-water waves, plasmas and other *** analysis is passed through via symbolic ***-form equations are constructed and soliton solutions are *** solutions and interactions are ***-form Backlund transformation and a type of solutions are obtained.

关键词： extended (2 +1)-dimensional Konopelchenko-Dubrovsky equations in fluid mechanics Painleve analysis soliton solutions Backlund transformation symbolic computation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Convection and Stratification of Temperature and Concentration

引用

fluid Dynamics & Materials Processing 2024年第6期20卷 1351-1364页

作者： Alexey Fedyushkin laboratory of complex fluid mechanics Ishlinsky Institute for Problems in Mechanics RASMoscow119526Russia

This study is devoted to an analysis of natural convection and the emergence of delamination in an incompressible fluid encapsulated in a closed region heated from the ***,medium and intensive modes of stationary laminar thermal and thermo-concentration convection are *** is shown that nonlinear flow features can radically change the flow structure and characteristics of heat and mass ***,the temperature and concentration segregation in the center of the square region display a non-monotonic dependence on the Grashof number(flow intensity).The formation of a nonstationary periodic structure of thermal convection in boundary layers and in the core of a convective flow in the closed region is also *** of the formation of countercurrents inside the region with the direction opposite to the main convective flow are ***,the influence of vertical and horizontal vibrations on oscillatory convection is analyzed in detail.

关键词： Natural convection stratification segregation numerical simulation vibrations

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of pitch angle on initial stage of a transport airplane ditching

引用

Chinese Journal of Aeronautics 2013年第1期26卷 17-26页

作者： Guo Baodong Liu Peiqing Qu Qiulin Wang Jiawen Institute of fluid mechanics Beihang University Key laboratory of fluid mechanics Ministry of Education Beihang University

Airworthiness regulations require that the transport airplane should be proved to ensure the survivability of the ditching for the passengers. The planned ditching of a transport airplane on the calm water is numerically simulated. The effect of pitch angle on the impact characteristics is especially investigated by a subscaled model. The Reynolds-averaged Navier-Stokes （RANS） equations of unsteady compressible flow are solved and the realizable j-e equations are employed to model the turbulence. The transformation of the air-water interface is tracked by volume of fluid （VOF） model. The motion of the rigid body is modeled by dynamic mesh method. The initial ditching stage of the transport airplane is analyzed in detail. The numerical results show that as the pitching angle increases, the maximal normal force decreases and the pitching motion becomes much gentler. The aft fuselage would be sucked down by the water and lead to pitching up, whereas the low horizontal tail prevents this trend. Consequently, the transport aircraft with low horizontal tail should ditch on the water at an angle between 10 and 12 as a recommendation.

关键词： Crashworthiness fluid structure interaction Hydrodynamics Multiphase flow Transport aircraft Water landing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Review on development of volumetric particle image velocimetry

引用

Chinese Science Bulletin 2013年第36期58卷 4541-4556页

作者： GAO Qi WANG HongPing SHEN GongXin Key laboratory of fluid mechanics Ministry of Education Institute of Fluid Mechanics Beijing University of Aeronautics and Astronautics

Volumetric particle image velocimetry(PIV)is a laser technique measuring three-component velocity field in a *** volumetric PIV techniques are defocusing PIV,multi-view PIV and holographic *** PIV is an advanced approach of multi-view PIV,which significantly improves the spatial resolution of the measurement by using the multiplicative algebraic reconstruction technique(MART)to reconstruct the particle *** to the rapid progress being made in volumetric PIV measurements,this article focuses on introducing the principles of different volumetric PIV methods from aspects of particle reconstruction and velocity *** and limitations on applications are *** specific to volumetric PIV regarding illumination,digital imaging,depth of focus,ghost particle and spatial resolution are discussed.

关键词：粒子图像测速技术体积 PIV技术空间分辨率代数重建技术技术测量容积测量应用程序

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The effects of corrugation and wing planform on the aerodynamic force production of sweeping model insect wings

引用

Acta Mechanica Sinica 2005年第6期21卷 531-541页

作者： Guoyu Luo Mao Sun Ministry-of-Education Key laboratory of fluid mechanics Institute of Fluid Mechanics Beihang University Beijing 100083 China

The effects of corrugation and wing planform （shape and aspect ratio） on the aerodynamic force production of model insect wings in sweeping （rotating after an initial start） motion at Reynolds number 200 and 3500 at angle of attack 40℃ are investigated, using the method of computational fluid dynamics. A representative wing corrugation is considered. Wing-shape and aspect ratio （AR） of ten representative insect wings are considered; they are the wings of fruit fly, cranefly, dronefly, hoverfly, ladybird, bumblebee, honeybee, lacewing （forewing）, hawkmoth and dragon- fly （forewing）, respectively （AR of these wings varies greatly, from 2.84 to 5.45）. The following facts are shown. （1） The corrugated and flat-plate wings produce approximately the same aerodynamic forces. This is because for a sweeping wing at large angle of attack, the length scale of the corrugation is much smaller than the size of the separated flow region or the size of the leading edge vortex （LEV）. （2） The variation in wing shape can have considerable effects on the aerodynamic force; but it has only minor effects on the force coefficients when the velocity at r2 （the radius of the second ：moment of wing area） is used as the reference velocity; i.e. the force coefficients are almost unaffected by the variation in wing shape. （3） The effects of AR are remarkably small： whenAR increases from 2.8 to 5.5, the force coefficients vary only slightly; flowfield results show that when AR is relatively large, the part of the LEV on the outer part of the wings sheds during the sweeping motion. As AR is increased, on one hand, the force coefficients will be increased due to the reduction of 3-dimensional flow effects; on the other hand, they will be decreased due to the shedding of part of the LEV; these two effects approximately cancel each other, resulting in only minor change of the force coefficients.

关键词： insect flight - Sweeping wing Unsteady aerodynamics Wing corrugation Planform

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：