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Science China Mathematics 2024年第11期67卷 2485-2514页

作者： Zefu Feng Guangyi Hong changjiang zhu School of Mathematical Sciences Chongqing Normal University School of Mathematics South China University of Technology

In this paper,we consider 3D compressible magneto-micropolar fluids without resistivity and spin viscosity in a strip *** prominent character of the governing model is the presence of the microstructure,a linear coupling structure involving derivatives of the velocity fields,which along with the lack of spin viscosity brings several challenges to the *** exploiting the two-tier energy method developed in Guo and Tice(Arch Ration Mech Anal,2013),we prove the global existence of classical solutions to the governing model around a uniform magnetic field that is non-parallel to the horizontal ***,we show that the solution converges to the steady state at an almost exponential rate as time goes to *** of the main ingredients in our analysis,compared with previous works on micropolar fluids,is that we deal with the microstructure by establishing some delicate estimates based on the analysis of the div-curl decomposition,and the coupling between the fluid velocity and the vorticity of angular velocity.

关键词： magneto-micropolar fluids compressible global existence large-time behavior

新型爆破掘进施工方式与常规爆破施工方式的对比

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科技创新与生产力 2024年第8期45卷 137-138,141页

作者：朱长江甘肃工业职业技术学院甘肃天水741025

本文主要分析对比了近些年来工程施工中出现的几种新型掘进施工方法的优缺点,并通过与常规爆破施工方法进行对比,得出了常规爆破施工方法是完全无法被替代的掘进施工方式。本文旨在为爆破掘进施工方法的选择、爆破行业的稳定发展提供可... 详细信息

本文主要分析对比了近些年来工程施工中出现的几种新型掘进施工方法的优缺点,并通过与常规爆破施工方法进行对比,得出了常规爆破施工方法是完全无法被替代的掘进施工方式。本文旨在为爆破掘进施工方法的选择、爆破行业的稳定发展提供可借鉴的经验。

关键词：爆破方法常规爆破爆破原理爆破施工

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山西五家沟煤矿深孔强制放顶爆破方案设计

科技创新与生产力 2024年第3期45卷 140-141页

作者：朱长江张军甘肃工业职业技术学院甘肃天水741025 山西宏安爆破工程有限公司山西吕梁033000

本文通过对山西五家沟煤矿回采工作面工程概况和地质水文状况进行分析,应用深孔爆破强制放顶技术原理,合理设计出该矿回采工作面的深孔爆破方案,后期又设计出新型分段式装药爆破试验方法,为安全高效地完成该矿的生产任务提供了有力的技... 详细信息

本文通过对山西五家沟煤矿回采工作面工程概况和地质水文状况进行分析,应用深孔爆破强制放顶技术原理,合理设计出该矿回采工作面的深孔爆破方案,后期又设计出新型分段式装药爆破试验方法,为安全高效地完成该矿的生产任务提供了有力的技术支持。

关键词：地质概况回采工作面深孔强制放顶爆破方案

L^p-decay rates to nonlinear diffusion waves for p-system with nonlinear damping

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Science China Mathematics 2006年第6期49卷 721-739页

作者： zhu changjiang JIANG Mina Laboratory of Nonlinear Analysis Department of Mathematics Central China Normal University Wuhan 430079 China Laboratory of Nonlinear Analysis Department of Mathematics Central China Normal University Wuhan 430079 China

In this paper, we study the Lp (2≤p≤ +∞) convergence rates of the solutions to the Cauchy problem of the so-called p-system with nonlinear damping. Precisely, we show that the corresponding Cauchy problem admits a unique global solution (v (x,t), u(x, t)) and such a solution tends time-asymptotically to the corresponding nonlinear diffusion wave ((v|-)(x,t),(u|-)(x,t)) governed by the classical Darcy's law provided that the corresponding prescribed initial error function lies in and is sufficiently small. Furthermore, the Lp (2≤p≤ +∞) convergence rates of the solutions are also obtained.

关键词： nonlinear damping, nonlinear diffusion waves, convergence rates, energy estimates.

The global classical solution to a 1D two-fluid model with density-dependent viscosity and vacuum

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Science China Mathematics 2022年第12期65卷 2563-2582页

作者： Senming Chen changjiang zhu Department of Mathematics Shantou UniversityShantou 515063China School of Mathematics South China University of TechnologyGuangzhou 510641China

In this paper, we consider the initial-boundary problem for a 1D two-fluid model with densitydependent viscosity and vacuum. The pressure depends on two variables but the viscosity only depends on one of the densities. We prove the global existence and uniqueness of the classical solution in the one-dimensional space with large initial data and vacuum. We use a new Helmholtz free energy function and the material derivative of the velocity field to deal with the general pressure with two variables, without the equivalence condition. We also develop a new argument to handle the general viscosity.

关键词： two-fluid model density-dependent viscosity vacuum global classical solution

Global weak solutions and asymptotics of a singular PDE-ODE chemotaxis system with discontinuous data

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Science China Mathematics 2022年第2期65卷 269-290页

作者： Hongyun Peng Zhi-An Wang changjiang zhu School of Applied Mathematics Guangdong University of TechnologyGuangzhou 510520China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong Kong 999077China School of Mathematics South China University of TechnologyGuangzhou 510641China

This paper is concerned with the well-posedness and large-time behavior of a two-dimensional PDE-ODE hybrid chemotaxis system describing the initiation of tumor angiogenesis. We first transform the system via a Cole-Hopf type transformation into a parabolic-hyperbolic system and then show that the solution to the transformed system converges to a constant equilibrium state as time tends to infinity. Finally we reverse the Cole-Hopf transformation and obtain the relevant results for the pre-transformed PDE-ODE hybrid *** contrast to the existing related results, where continuous initial data is imposed, we are able to prove the asymptotic stability for discontinuous initial data with large oscillations. The key ingredient in our proof is the use of the so-called "effective viscous flux", which enables us to obtain the desired energy estimates and regularity. The technique of the "effective viscous flux" turns out to be a very useful tool to study chemotaxis systems with initial data having low regularity and was rarely(if not) used in the literature for chemotaxis models.

关键词： chemotaxis asymptotic stability discontinuous initial data effective viscous flux

间隔装药的殉爆起爆技术在露天矿山爆破中的应用

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露天采矿技术 2024年第2期39卷 42-45页

作者：朱长江王永星甘肃工业职业技术学院甘肃天水741025 浙江甬大建设有限公司浙江宁波315000

为了降低西沟露天石料厂的采石爆破成本,提高经济效益;应用空气袋间隔装药装置技术进行了150 mm炮孔和100 mm炮孔的爆破实验对比,同时进行了露天炮孔孔内反向和正向起爆殉爆试验对比。结果表明:采用炮孔中部空气袋间隔装置的露天矿台阶... 详细信息

为了降低西沟露天石料厂的采石爆破成本,提高经济效益;应用空气袋间隔装药装置技术进行了150 mm炮孔和100 mm炮孔的爆破实验对比,同时进行了露天炮孔孔内反向和正向起爆殉爆试验对比。结果表明:采用炮孔中部空气袋间隔装置的露天矿台阶爆破,电子雷管起爆一端装药之后再利用其爆轰波殉爆起爆另一端装药,孔径大的炮孔比孔径小的炮孔殉爆起爆的爆破效果好;采用殉爆起爆技术后,做到了节能减排和提效;反向起爆爆破法与正向起爆爆破法相比,爆破效果更好。

关键词：殉爆起爆空气袋间隔装置底部(上部)装药爆破法节能减排提效

Convergence to diffusion waves for solutions of Euler equations with time-depending damping on quadrant

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Science China Mathematics 2019年第1期62卷 33-62页

作者： Haibo Cui Haiyan Yin changjiang zhu Limei zhu School of Mathematical Sciences Huaqiao University School of Mathematics South China University of Technology

This paper is concerned with the asymptotic behavior of the solution to the Euler equations with time-depending damping on quadrant(x,t)∈R^+×R^+,with the null-Dirichlet boundary condition or the null-Neumann boundary condition on u. We show that the corresponding initial-boundary value problem admits a unique global smooth solution which tends timeasymptotically to the nonlinear diffusion wave. Compared with the previous work about Euler equations with constant coefficient damping, studied by Nishihara and Yang(1999), and Jiang and zhu(2009, Discrete Contin Dyn Syst), we obtain a general result when the initial perturbation belongs to the same space. In addition,our main novelty lies in the fact that the cut-off points of the convergence rates are different from our previous result about the Cauchy problem. Our proof is based on the classical energy method and the analyses of the nonlinear diffusion wave.

关键词： Euler equations with time-depending damping nonlinear diffusion waves initial-boundary value problem decay estimates

高分何以上职校?——社会生态系统理论视角下初中毕业生教育抉择探究

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职教发展研究 2024年第2期 43-52页

作者：陈鹏朱长江雍蓉江苏师范大学教育科学学院江苏徐州221116

在普职协调发展背景下,初中毕业生在普职分流的选择中逐渐有了更加理性的抉择。随着职业教育贯通培养政策的落实和推广,越来越多的初中毕业生高分选择通过攻读职业院校实现学业进阶,引起社会公众的强烈反响,并呈现出两种完全相反的态度... 详细信息

在普职协调发展背景下,初中毕业生在普职分流的选择中逐渐有了更加理性的抉择。随着职业教育贯通培养政策的落实和推广,越来越多的初中毕业生高分选择通过攻读职业院校实现学业进阶,引起社会公众的强烈反响,并呈现出两种完全相反的态度。为进一步探究考生“高分上职校”这一现象背后的深层原因,研究使用网络爬虫技术在新浪微博中收集数据,以社会生态系统理论为分析框架,从宏观、中观、微观以及时间系统四个层次分析贯通培养项目选择背后的社会文化体制、家庭资本和同伴文化、个体个性等原因以及生态变迁的逻辑。社会原因主要表现为体制之风及女性刻板印象、科举制遗留下的“学历至上”思想,家庭原因主要表现为家庭文化经济资本以及同伴文化,个体原因表现为性格和兴趣,生态变迁逻辑表现为积极、消极变化以及物理、精神变化方面。为此,建议进一步拓展职业教育贯通培养项目的合作类型、专业类别、定向领域,从而切实提高职业教育的吸引力。

关键词：高分升学普职分流贯通培养社会生态系统理论

REVIEW ON MATHEMATICAL ANALYSIS OF SOME TWO-PHASE FLOW MODELS

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Acta Mathematica Scientia 2018年第5期38卷 1617-1636页

作者： Huanyao WEN Lei YAO changjiang zhu School of Mathematics South China University of TechnologyGuangzhou 510641China School of Mathematics and Center for Nonlinear Studies Northwest UniversityXi＇an 710127China

The two-phase flow models are commonly used in industrial applications, such as nuclear, power, chemical-process, oil-and-gas, cryogenics, bio-medical, micro-technology and so on. This is a survey paper on the study of compressible nonconservative two-fluid model, drift-flux model and viscous liquid-gas two-phase flow model. We give the research developments of these three two-phase flow models, respectively. In the last part, we give some open problems about the above models.

关键词： compressible nonconservative two-fluid model drift-flux model viscous liquid-gas two-phase flow model well-posedness