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The Numerical Simulation of Flow Field of Jet System

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Journal of Systems Engineering and Electronics 1993年第3期4卷 62-69页

作者： guo jinji, Zhang Sheng and Chen TongMechanics Dept. of Zhongshan University,Guangzhou 510275. China Mechanics Dept. of Zhongshan University Guangzhou 510275 China

In this paper, the internal fluid motion of a jet system is described by the Navier Stokes mechanics equations. For the simulation of the motion, the penalty function finite element method is used, and the velocity vectors and stream function curves are obtained. Using the Prandtl theory, this paper derives the free jet velocity and the jet bunch width in a half-space, the latter of which is amended by experiment. The results obtained in this paper are applied to micro-type high pressure water jet cleaner and the ejector of rocket engine.

关键词： Fluid mechanics equations Penalty finite element method Numerical simulation Free jet Jet bunch width.

Calculation　and　Test　of　Hitting　Force　of　Firing　Bullet　on　the　Bulletproof　Helmet

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Journal of Systems Engineering and Electronics 1998年第3期9卷 69-76页

作者： jinji, guo Haoxu, Xing Gao, Yang Chengbai, Wu Jincai, Pei Zhijian, Liu Dept. of Applied Mechanics and Engineering. Zhongshan University. Guangzhou 510275 P. R. China The Institute of Guangdong Public Security Science and Technology Guangzhou 510275. P. R. China The Iron and Steel Institute of Guangdong Guangzhou 510275 P. R. China

In this paper the hit force of firing bullet on bulletproof helmet has been computed and the test device has been described. The device is divided into two parts: 1) The bullet, helmet and mould are in one system, using moment theorem to calculate the hit force; 2) The mould, sensor and support pole are in one system, using the method in reference [1] that measures the dynamic strain and displacement of simulate target of bulletproof clothes. We compute the transfigure energy and momentum energy when hitting the mould, the work done by the sensor and the expend energy of support pole. We get the hit force of helmet using energy balance principle. The result is according with the test and has been used to design the GGK93T bulletproof helmet and other serial products.

关键词： Bulletproof helmet Bullet hit force Head mould Force sensor Hitting energy

Theoretical Computation of Nonlinear System Equations of Heavier Pellets Movements for Two Phase Flow

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Journal of Systems Engineering and Electronics 1992年第3期3卷 59-68页

作者： guo jinji and Zhan ShengDept. of Applied Mechanics and Engineering, Zhongshan University, Guangzhou 510275, P.RChina Dept. of Applied Mechanics and Engineering Zhongshan University Guangzbou 510275 P.R China

This paper presents nonlinear ordinary differential equations (ODES) of the heavier pellets movement for two phase flow, which actually represent a system of equations. The usual methods of solution such as Runge -Kutta method and it's datum results are discussed. This paper solves ODES of general form using variable mesh-length, linearizing the nonlinear terms by finite analysis method, fuilding an iteration sequence, and amending the nonlinear terms by iteration . The conditions of convergent operation of iteration solution is checked. The movement orbit and velocity of the pellets are calculated. Analysis of research results and it's application examples are illustrated.

关键词： Heavier pellets movement Two phase flow Nonlinear system equations Finite analysis method Iteration approach solutions.

A Slip-Line Method for Calculating Extrusion Force of Steel Helmet with Cold Extrusion Moulding

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Journal of Systems Engineering and Electronics 1999年第2期10卷 75-81页

作者： guo jinji Zhao Sheng Xing Haoxu(Department of Applied Mechanics and Engineering, Zhongshan University,Guangzhou 510275, P. R. China)Guan Guifen Liu Zhijian(The Iron Steel Research institute of Guangdong,Guangzhou 510275, P. R. China) Department of Applied Mechanics and Engineering Zhongshan University Guangzhou 510275 P. R. China The Iron Steel Research Institute of Guangdong Guangzhou 510275 P. R. China

This paper presents the elastic and plastic deformation of the steel helmet with coldextrusion moulding. The plastic streamline of the plastic mould-making process for ellipse thinplate is described. The distribution of slip-line is established based on the plastic streamline. Theextrusion force of plastic moulding of the steel helmet is calculated by using of slip-line ***, an applied example is given.

关键词： Steel helmet Cold extrusion Plastic streamline slip-line method Extrusion force.

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亚音速气体喷射器的理论计算

流体工程 1989年第7期17卷 18-22页

作者：郭金基中山大学

本文在前文[1]、[2]基础上研究亚音速气体喷射器的理论计算问题。从优化条件导出最佳截面比,利用自由射流束长度取极值条件并联系流控端口特性的方程确定其几何尺寸。文中还讨论了给出的计算公式适用范围及应用效果。

关键词：气体喷射器亚音速计算

天津关隧道软岩大变形段锁脚锚杆支护技术研究

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施工技术（中英文） 2022年第13期51卷 81-83,90页

作者：佟晓冬郭金冀谭贤君中交一公局第五工程有限公司北京100024 中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室湖北武汉430071

锁脚锚杆在软弱围岩隧道中应用非常广泛,为研究其受力特性,以天津关软岩隧道为依托,采用现场试验与理论分析相结合的方法,研究锁脚锚杆的支护效果、提出进一步优化措施,并研究锚杆直径和长度对支护效果的影响。研究结果表明,虽然ϕ42×4... 详细信息

锁脚锚杆在软弱围岩隧道中应用非常广泛,为研究其受力特性,以天津关软岩隧道为依托,采用现场试验与理论分析相结合的方法,研究锁脚锚杆的支护效果、提出进一步优化措施,并研究锚杆直径和长度对支护效果的影响。研究结果表明,虽然ϕ42×4锁脚锚杆的支护效果好于ϕ22早强砂浆锁脚锚杆,但依然不能很好地控制围岩变形。相比ϕ42×4锁脚锚杆,ϕ89×6锁脚锚杆能很好地控制围岩变形,说明锁脚锚杆管径对其支护效果具有重要影响。围岩变形速率与隧道开挖过程有密切关系,采用三台阶七步开挖法施工时,要特别重视第3步开挖时的支护。

关键词：隧道软弱围岩锁脚锚杆支护变形

High cerium content(Nd-Pr-Ce)_(2)Fe_(14)B melt-spun ribbons with high coercivity

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Journal of Rare Earths 2024年第4期42卷 690-695页

作者： Yujiang Zhong Junming Wang Zikai Yuan Ruijin Liu Minggang Zhu Zhe Liu Xin Chen Wei Li Zhaohui guo Division of Functional Materials Central Iron and Steel Research InstituteBeijing100081China Ningbo jinji Strong Magnetic Material Co. Ltd.Ningbo315172China Jiangxi Jiangwu Rare Metal New Material Co. Ltd.Nanchang330013China

The effects of wheel speeds on the magnetic properties and microstructures of[(Nd,Pr)_(1-x)Ce_(x)]-Fe-B meltspun ribbons were *** to melt-spun ribbons with low cerium(Ce)content(x=0.2),amorphous formation can be suppressed at high wheel speed in the ribbons with a relatively high Ce content(x=0.8),and with the increase of the wheel speed,the magnetic properties of the ribbons with high Ce content raise *** high wheel speed,the coercivity mechanism of melt-spun ribbons is mainly pinning field,and the high wheel speed introduces a large number of defects into the matrix as pinning ***,ribbons with high Ce content form a fine and uniform grain structure,so the grain boundary area enlarges,which further hinders the movement of domain *** combined effects of the above factors enable ribbons with high Ce content to have excellent magnetic properties(Hcj=0.977 T,Mr=64 m^(2) A/kg)at the wheel speed of 35 m/s.

关键词： Wheel speed Cecontent Microstructure Magnetic properties Rare earths