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Numerical study on the case effect of a bomb air explosion

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Defence Technology（防务技术） 2021年第4期17卷 1461-1470页

作者： guo-qiang Deng Xiao Yu Institute of Defense Engineering AMSPLABeijing100850China

When considering the bomb explosion damage effect,the air shock wave and high-speed fragments of the bomb case are two major *** experiments,the air shock wave was studied by the bare explosives superseding the real cased bomb;in contrast,the bomb case influence was ignored to reduce *** air explosion simulations of the MK84 warhead with and without the case were *** numerical simulation results showed that the bomb case significantly influenced the shock wave generated by the bomb:the spatial distribution of shock wave in the near field changed,and the peak value of shock wave was *** of the case and kinetic energy of the fragmentation consumed 3 and 38% of the explosion energy,*** increasing factors of the peak overpressure induced by the bare explosive on the ground and in the air were 1.43-3.04 and 1.37-1.57,*** typical stages of case breakage were *** mass distribution of the fragments follows the Mott *** initial velocity distribution of the fragments agreed well with the Gurney equation.

关键词： Explosion Cased bomb Bare explosive Numerical simulation MK84

Spontaneous Infection and Periodic Evolving of Domain in a Diffusive SIS Epidemic Model

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 164-191页

作者： qiang Wen guo-qiang Ren Bin Liu School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan430074China

In this paper, we consider a susceptible-infective-susceptible(SIS) reaction-diffusion epidemic model with spontaneous infection and logistic source in a periodically evolving domain. Using the iterative technique,the uniform boundedness of solution is established. In addition, the spatial-temporal risk index R0(ρ) depending on the domain evolution rate ρ(t) as well as its analytical properties are discussed. The monotonicity of R0(ρ)with respect to the diffusion coefficients of the infected dI, the spontaneous infection rate η(ρ(t)y) and interval length L is investigated under appropriate conditions. Further, the existence and asymptotic behavior of periodic endemic equilibria are explored by upper and lower solution method. Finally, some numerical simulations are presented to illustrate our analytical results. Our results provide valuable information for disease control and prevention.

关键词： diffusive SIS model spontaneous infection periodically evolving domain periodic endemic equilibrium

Signal classification method based on data mining formulti-mode radar

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Journal of Systems Engineering and Electronics 2016年第5期27卷 1010-1017页

作者： qiang guo pulong nan jian wan College of Information and Communication Engineering Harbin Engineering University Harbin 150001 China

For the multi-mode radar working in the modern electronicbattlefield, different working states of one single radar areprone to being classified as multiple emitters when adoptingtraditional classification methods to process intercepted signals,which has a negative effect on signal classification. A classificationmethod based on spatial data mining is presented to address theabove challenge. Inspired by the idea of spatial data mining, theclassification method applies nuclear field to depicting the distributioninformation of pulse samples in feature space, and digs out thehidden cluster information by analyzing distribution *** addition, a membership-degree criterion to quantify the correlationamong all classes is established, which ensures classificationaccuracy of signal samples. Numerical experiments show that thepresented method can effectively prevent different working statesof multi-mode emitter from being classified as several emitters,and achieve higher classification accuracy.

关键词： multi-mode radar signal classification data mining,nuclear field cloud model membership.

Redesigned Surface Based Machining Strategy and Method in Peripheral Milling of Thin-walled Parts

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Chinese Journal of Mechanical Engineering 2010年第3期23卷 282-287页

作者： JIA Zhenyuan guo qiang SUN Yuwen guo Dongming Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of Technology Dalian 116024 China

Currently, simultaneously ensuring the machining accuracy and efficiency of thin-walled structures especially high performance parts still remains a challenge. Existing compensating methods are mainly focusing on 3-aixs machining, which sometimes only take one given point as the compensative point at each given cutter location. This paper presents a redesigned surface based machining strategy for peripheral milling of thin-walled parts. Based on an improved cutting force/heat model and finite element method（FEM） simulation environment, a deflection error prediction model, which takes sequence of cutter contact lines as compensation targets, is established. And an iterative algorithm is presented to determine feasible cutter axis positions. The final redesigned surface is subsequently generated by skinning all discrete cutter axis vectors after compensating by using the proposed algorithm. The proposed machining strategy incorporates the thermo-mechanical coupled effect in deflection prediction, and is also validated with flank milling experiment by using five-axis machine tool. At the same time, the deformation error is detected by using three-coordinate measuring machine. Error prediction values and experimental results indicate that they have a good consistency and the proposed approach is able to significantly reduce the dimension error under the same machining conditions compared with conventional methods. The proposed machining strategy has potential in high-efficiency precision machining of thin-walled parts.

关键词： redesigned surface tool path part deflection error prediction finite element method

New Mathematical Method for the Determination of Cutter Runout Parameters in Flat-end Milling

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 947-952页

作者： guo qiang SUN Yuwen guo Dongming ZHANG Chuantai Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024China

The cutting force prediction is essential to optimize the process parameters of machining such as feed rate optimization, etc. Due to the significant influences of the runout effect on cutting force variation in milling process, it is necessary to incorporate the cutter runout parameters into the prediction model of cutting forces. However, the determination of cutter runout parameters is still a challenge task until now. In this paper, cutting process geometry models, such as uncut chip thickness and pitch angle, are established based on the true trajectory of the cutting edge considering the cutter runout effect. A new algorithm is then presented to compute the cutter runout parameters for flat-end mill utilizing the sampled data of cutting forces and derived process geometry parameters. Further, three-axis and five-axis milling experiments were conducted on a machining centre, and resulting cutting forces were sampled by a three-component dynamometer. After computing the corresponding cutter runout parameters, cutter forces are simulated embracing the cutter runout parameters obtained from the proposed algorithm. The predicted cutting forces show good agreements with the sampled data both in magnitude and shape, which validates the feasibility and effectivity of the proposed new algorithm of determining cutter runout parameters and the new way to accurately predict cutting forces. The proposed method for computing the cutter runout parameters provides the significant references for the cutting force prediction in the cutting process.

关键词： flat end milling cutter runout cutting force five-axis machining

Analytical modeling of geometric errors induced by cutter runout and tool path optimization for five-axis flank machining

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Science China(Technological Sciences) 2011年第12期54卷 3180-3190页

作者： guo qiang SUN YuWen guo DongMing Key Laboratory for Precision and Non-Traditional Machining Technology of the Ministry of Education Dalian University of Technology Dalian 116024 China

The cutter runout effect has significant influence on the shape of cutter swept surface and the machining surface quality. Hence,it is necessary to integrate the cutter runout effect in cutter swept surface modeling,geometric error prediction and tool path optimization for five-axis flank machining. In this paper,an envelope surface model considering cutter runout effect is first established,and geometric errors induced by runout effect are derived based on the relative motion analysis between the cutter and part in machining. In the model,the cutter runout is defined by four parameters,including inclination angle,location angle,offset value and the length of cutter axis. Then the runout parameters are integrated into the rotation surface of each cutting edge that is used to form the final cutter envelope surface for the five-axis machining process. Thus,the final resulting geometric errors of the machined surface induced by cutter runout can be obtained through computing the deviations from the nominal cutter swept surface. To reduce these errors,an iterative least square method is used to optimize the tool paths for five-axis flank machining. Finally,a validation example is given for a specific ruled surface. Results show the effectiveness and feasibility of the analytical model of geometric errors induced by cutter runout,and also show that the geometric errors can be reduced significantly using the proposed tool path planning method.

关键词： cutter runout tool path optimization envelope surface five-axis machining geometric errors

Recent Advances in Pd-Catalyzed Reactions Involving the “On-Water” Mechanism

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Chinese Journal of Chemistry 2024年第5期42卷 533-542页

作者： Dong Wei guo-qiang Lin State Key Laboratory of Systems Medicine for Cancer Shanghai Cancer InstituteShanghai Key Laboratory of Systems Regulation and Clinical Translation for CancerRen Ji HospitalShanghai Jiao Tong University School of MedicineShanghai200127 China State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai200032 China

As the chemical industry grapples with the need for more eco-friendly practices,the use of water as a reaction medium is gaining attraction in organic *** mini-review delves into Pd-catalyzed reactions that utilize the "on-water" mechanism,spanning from 2019 to late *** reactions are neatly categorized into several types: (A) Catalytic C—H activations,(B) Mizoroki- Heck-type reactions,(C) Suzuki-Miyaura reactions,and (D) Cyclization *** showcasing the potential of water as a sustainable reaction medium for organic transformations,these reactions leave no doubt about the importance of embracing eco-friendly practices in the chemical *** Scientists In 1980,a seminal work by Breslow et *** an acceleration of reaction rate in the Diels-Alder *** and co-workers noted a significant increase in the rate of the [2σ+2σ+2π] cycloaddition of quadricyclane and dimethyl azodicarboxylate (DMAD) when the reaction was conducted in water,as opposed to when it was carried out in organic *** term "on-water" was then coined to describe this *** strategy was further expanded to transition-metal catalyzed transformations by Ackermann in ***,Varma and Leazer disclosed a Pd-catalyzed Mizoroki-Heck type arylation of alkenes with diaryliodonium salts “on-water”.The enantioselective version of "on-water" process was not realized until 2014 by the Zhou *** on,the Schaub group described a Pd-catalyzed Suzuki–Miyaura coupling reaction of electron-poor aryl chlorides with water,using only 50 ppm of catalyst *** recently,Liu and Lin extended the "on-water" strategy to Pd-catalyzed double Mizoroki-Heck *** mini-review has focused on Pd-catalyzed reactions involving the “on-water” mechanism.

关键词： Pd-catalyzed “On-water” Green chemistry Aqueous reactions Mechanism Methodology and reactions Mizoroki-Heck reaction Cross-coupling

Pulse-to-pulse periodic signal sorting features and feature extraction in radar emitter pulse sequences

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Journal of Systems Engineering and Electronics 2010年第3期21卷 382-389页

作者： qiang guo Zhenshen Qu Changhong Wang College of Information and Communication Engineering Harbin Engineering University Harbin 150001 R R. China Space Control and Inertial Technology Research Center Harbin Institute of Technology Harbin 150001 R R. China

A novel class of periodically changing features hidden in radar pulse sequence environment,named G features,is *** fractal theory and Hilbert-Huang transform,the features are extracted using changing characteristics of pulse parameters in radar emitter *** features can be applied in modern complex electronic warfare environment to address the issue of signal sorting when radar emitter pulse signal parameters severely or even completely *** results show that the proposed feature class and feature extraction method can discriminate periodically changing pulse sequence signal sorting features from radar pulse signal flow with complex variant features,therefore provide a new methodology for signal sorting.

关键词： signal sorting fractal geometry Hilbert-Huang transform(HHT) G feature extraction.

Functionalization of C,C-palladacycles:application in the synthesis of functional molecules

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Science China Chemistry 2023年第10期66卷 2721-2733页

作者： Dong Wei guo-qiang Lin State Key Laboratory of Systems Medicine for Cancer Shanghai Cancer InstituteRen Ji HospitalShanghai Jiao Tong University School of MedicineShanghai 200127China Key Laboratory of Synthetic Chemistry of Natural Substances Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Significant advancements have been achieved in the field of C,C-palladacycles functionalization in recent decades,which have greatly contributed to the synthesis of intricate drug molecules,natural products,innovative materials,and chiral ***,these advancements have led to the establishment of highly efficient and atom-economic synthetic *** on the differences in the C–Pd bonds,C,C-palladacycles can be further classified into several main types:C(aryl),C(alkyl)-,C(aryl),C(aryl)-,C(aryl),C(vinyl)-,and C(alkyl),C(carbonyl)-*** minireview will highlight the recent advances in the synthesis of functional molecules through the functionalization of different C,C-palladacycles,and we hope this survey will inspire future strategic developments for C,C-palladacycle catalysts and their synthetic application.

关键词： C,C-palladacycles functionalization synthetic application