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PROGRESSIVE FRACTURE MODELING OF THE FAILURE WAVE IN IMPACTED GLASS

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Acta Mechanica Solida Sinica 2006年第1期19卷 69-74页

作者： Yao Guowen liu zhanfang Huang Peiyan College of Civil Engineering and Architecture Chongqing Jiaotong University Chongqing 400074 China Department of Engineering Mechanics Chongqing University Chongqing 400044 China College of Traffic and Communications South China University of Technology Guangzhou 510640 China

The failure wave has been observed propagating in glass under impact loading since 1991. It is a continuous fracture zone which may be associated with the damage accumulation process during the propagation of shock waves. A progressive fracture model was proposed to describe the failure wave formation and propagation in shocked glass considering its heterogeneous meso-structures. The original and. nucleated microcracks will expand along the pores and other defects with concomitant dilation when shock loading is below the Hugoniot Elastic Limit. The governing equation of the failure wave is characterized by inelastic bulk strain with material damage and fracture. And the inelastic bulk strain consists of dilatant strain from nucleation and expansion of microcracks and condensed strain from the collapse of the original pores. Numerical simulation of the free surface velocity was performed and found in good agreement with planar impact experiments on K9 glass at China Academy of Engineering Physics. And the longitudinal, lateral and shear stress histories upon the arrival of the failure wave were predicted, which present the diminished shear strength and lost spall strength in the failed layer.

关键词： the failure wave progressive fracture model glass planar impact

An analysis on a rigid-flexible coupling system of an oscillating massand a rotating disk

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Theoretical & Applied Mechanics Letters 2022年第5期12卷 341-348页

作者： Jian liu Kai Zhang zhanfang liu College of Aerospace Engineering Chongqing UniversityChongqing 400040China CSSC Haizhuang Wind Power Co. LTDChongqing 401123China State Key Laboratory of Ultrasound in Medicine and Engineering Chongqing Medical UniversityChongqing 400016China

A mass-rod-disk system consisting of an oscillating mass attached to a rigid rotating disk by an elastic rod is designed to study rigid-flexible coupling *** the rod is lightweight and has enough stiffness,the theorems of linear momentum and angular momentum are applied to the mass-rod-disk system based on the kinematic description of the *** respect to two deflections of the mass and one angular velocity of the system,a group of nonlinear differential equations are established where the tangential inertial force,centrifugal force,Coriolis force as well as the moments of additional inertial forces take important effects on the dynamic *** the sake of description,these three types of inertial forces mentioned before are referred to as additional inertial forces in this *** horizontal deflections of the mass and the angular velocity of the disk rotating about a fixed-axis are numerically solved for the prescribed external *** oscillating trajectory of the mass is deeply influenced by the additional inertial forces,meanwhile the dynamic fluctuations of the angular velocity and rotary inertia of the system are strongly affected by the mass oscillation.

关键词： Rigid-flexible coupling Additional inertial forces Nonlinear differential equation Motion trajectory

海上浮式兆瓦级垂直轴风力机风轮结构布局研究

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船舶工程 2024年第1期46卷 30-39页

作者：陈宇康刘占芳杨文英张浩程志龙重庆大学航空航天学院重庆400044 重庆大学非均质材料力学重庆市重点实验室重庆400044 上海船舶设备研究所上海200031 中船海装风电有限公司重庆401122

针对兆瓦级海上浮式直叶片垂直轴风力机的风轮结构布局,提出采用基于响应面法的多目标结构优化设计方法对其风轮进行结构布局设计。通过分析风轮支撑臂在复杂环境和载荷作用条件下的力学性能,以准静态解为基础构建垂直轴风轮结构布局多... 详细信息

针对兆瓦级海上浮式直叶片垂直轴风力机的风轮结构布局,提出采用基于响应面法的多目标结构优化设计方法对其风轮进行结构布局设计。通过分析风轮支撑臂在复杂环境和载荷作用条件下的力学性能,以准静态解为基础构建垂直轴风轮结构布局多目标优化参数化模型,采用Kriging响应面法求解设计变量与评价指标之间的响应面,明确设计变量的最优取值范围。以风轮整体质量最小化为优化目标,以风轮主要结构的最大等效应力和最大位移为约束条件,采用MOGA遗传算法对风轮结构布局尺寸进行优化设计,优化后风轮结构布局的最优样本方案在满足约束条件的同时,整体质量减轻6.8%,轮毂偏移量减少22.87%,塔筒高度降低33.78%,显著降低了垂直轴风力机整机的制造成本。同时,优化设计后风轮固有频率避开了风轮旋转的1倍转频(1P)和3倍转频(3P)范围,避免了结构共振。研究表明,基于响应面法的多目标优化设计方法在垂直轴风轮结构布局设计上是可靠的。

关键词：垂直轴风力机多目标优化响应面法结构布局设计准静态解

Application of GC-qqqMS/MS in Gasoline Grades and Regions Identification

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China Petroleum Processing & Petrochemical Technology 2022年第1期24卷 48-58页

作者： Wang Xin Zhang Guannan Zhu Jun Wan Yifu Jiang Hong liu zhanfang People’s Public Security University of China Beijing 100038 Material Evidence Center of the Ministry of Public Security Beijing 100038

Based on GC-qqqMS/MS,a qualitative and quantitative analysis method for identifying characteristic markers in gasoline samples was *** to the established method,different grades(#92,#95,#98)of gasoline samples collected from different regions(southern,central,northeastern,and northwestern China)were studied and *** results show that the gasolines can be classified by the relative contents of aromatics,naphthalene series,indene and other characteristic *** the basis of the high sensitivity and selectivity of GC-qqqMS/MS,the experiment has identified the characteristic substances,and used the characteristic-ratios methods as well as stoichiometric tools to study the grades and regional differences of gasoline *** is conducive to the identification and classification of ILR in public security in fire cases,and can also meet the actual handling demand.

关键词： GC-qqqMS/MS gasoline characteristic markers identification and classification

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调和汽油的GC-MS检验与区分

刑事技术 2024年第1期49卷 38-42页

作者：张冠男刘占芳孙振文周正李光耀李亚军邓显贺乔婷朱军公安部鉴定中心北京100038

调和汽油在涉火案件中出现的频率逐渐增加,其特殊的组成可能对成分研判造成干扰。为准确识别汽油组分,区分不同来源的调和汽油,本文依托气相色谱–质谱(GC-MS)检验了部分典型调和油品,分析了相关样品的谱图特征并进行归类。结果表明,案... 详细信息

调和汽油在涉火案件中出现的频率逐渐增加,其特殊的组成可能对成分研判造成干扰。为准确识别汽油组分,区分不同来源的调和汽油,本文依托气相色谱–质谱(GC-MS)检验了部分典型调和油品,分析了相关样品的谱图特征并进行归类。结果表明,案件中常见的调和油品按照谱图主要特点可划分为添加剂异常、异构烷烃异常、直链烷烃异常和多组分异常四类。其中前两类对汽油及其残留物鉴定基本不构成干扰,而直链烷烃异常类油品可能引起误判,多组分异常类油品则不宜轻易下汽油结论。该研究结果对特殊调和汽油及其残留物的检验鉴定有一定的指导意义,对于涉火案件中汽油的比对分析和来源推断具有实战应用价值。

关键词：微量物证气相色谱–质谱汽油涉火案件残留物

Determination of Diphenylamine in Gunshot Residue by HPLC‑MS/MS

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Journal of Forensic Science and Medicine 2016年第1期2卷 18-21页

作者： Hongcheng Mei Yangke Quan Wenhao Wang Hong Zhou zhanfang liu Huixia Shi Peng Wang Institute of Forensic Science Ministry of Public Security1College of Forensic SciencePeople’s Public Security University of ChinaBeijing Xianyang Public Security Bureau ShanxiChina

A high performance liquid chromatography tandem mass spectrometry/mass spectrometry(HPLC-MS/MS)protocol was developed for the determination of diphenylamine(DPA).Four productions of DPA were selected for qualitative assay and the peak area of the main product ion for *** means of separation using an Agilent Extend-C18 column(CA,USA)(150 mm×4.6 mm,5μm)with methanol‑water(90:10)as the mobile phase,DPA was detected by electrospray ionization(ESI)tandem mass spectrometry in positive *** linearity of the peak area versus concentration ranged 5‑500 ng/mL,r^(2)=*** limit of detection(S/N=3)of this method was 0.3 ng/*** method is applicable for the determination of DPA in gunshot residue.

关键词： Diphenylamine gunshot residue high performance liquid chromatography-mass spectrometry/mass spectrometry

修正的偶应力线弹性理论及广义线弹性体的有限元方法

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固体力学学报 2012年第3期33卷 279-287页

作者：颜世军刘占芳重庆大学资环学院工程力学系重庆400044

以含偶应力的弹性理论为基础,考虑小变形情况下变形体的平动变形和旋转变形,提出关于偶应力与曲率张量的线性本构关系,建立广义弹性体的线性模型.为放松单元C1连续性要求,考虑转角为独立变量,利用罚方法引入约束条件,构造广义线弹性体... 详细信息

以含偶应力的弹性理论为基础,考虑小变形情况下变形体的平动变形和旋转变形,提出关于偶应力与曲率张量的线性本构关系,建立广义弹性体的线性模型.为放松单元C1连续性要求,考虑转角为独立变量,利用罚方法引入约束条件,构造广义线弹性体的约束变分形式.应用8结点48个自由度的实体等参元,建立广义线弹性体力学响应分析的有限元方程.对悬臂梁的静力和动力分析表明,广义线弹性体模型较之经典弹性力学更适合结构分析;较之Timoshenko梁模型,广义线弹性体模型能够计及结构尺度对结构动力特性和动力响应造成的显著影响.

关键词：偶应力曲率张量动力特性有限元分析

Application of Spectra Accuracy for Analysis of Organic Explosive: 2,4,6‑trinitrotoluene by AccuTOF‑DART

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Journal of Forensic Science and Medicine 2016年第4期2卷 190-194页

作者： zhanfang liu Zhenwen Sun Guannan Zhang Jun Zhu Hongcheng Mei Haiyan Li Bin Li Jianzhong Xu Hong Zhou Institute of Forensic Science Ministry of Public Security1 Lumiere Tech.Ltd.BeijingChina

This paper,through mass spectrometric(MS)analysis for nitro compound explosives on a direct analysis in a real‑time time‑of‑flight MS,indicates that even on a high‑resolution MS with accurate mass measurement capabilities,there is no guarantee to obtain the unique molecular formula of a *** calculating spectra accuracy,highly accurate isotope pattern matching can be conducted to significantly improve performance of compound confirmation or identification.

关键词： 2,4,6‑trinitrotoluene direct analysis in real‑time time‑of‑flight mass spectrometer isotope pattern mass spectrometric analysis spectral accuracy

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三维光子晶体的制备

化学进展 2008年第9期20卷 1283-1293页

作者：丁涛刘占芳宋恺中国科学院化学研究所北京100190 吉林大学材料科学与工程学院长春130025

三维光子晶体作为一种光子带隙材料在光学器件、化学生物传感以及信息传输和存储等方面具有广泛的潜在应用价值。自1987年三维光子晶体的概念被提出以来,科学家们一直致力于在实验室用不同的手段合成不同材料和不同结构的光子晶体。本... 详细信息

三维光子晶体作为一种光子带隙材料在光学器件、化学生物传感以及信息传输和存储等方面具有广泛的潜在应用价值。自1987年三维光子晶体的概念被提出以来,科学家们一直致力于在实验室用不同的手段合成不同材料和不同结构的光子晶体。本文综述了近年来出现的一些三维光子晶体制备方法,大致分为3类:'自上而下法(top-down method)','自下而上法(bottom-up method)'和模板辅助法(template-assistedmethod),并详细阐述了每种方法的代表性工作、适用范围以及各自的优缺点。

关键词：光子晶体胶体晶体三维模板组装制备