Study on the coupling calculation method for the launch dynamics of a self-propelled artillery multibody system considering engraving process

The launch dynamics theory for multibody systems emerges as an innovative and efficacious approach for the study of launch dynamics,capable of addressing the challenges of complex modeling,diminished computational efficiency,and imprecise analyses of system dynamic responses found in the dynamics research of intricate multi-rigid-flexible body systems,such as self-propelled artillery.This advancement aims to enhance the firing accuracy and launch safety of self-propelled artillery.Recognizing the shortfall of overlooking the band engraving process in existing theories,this study introduces a novel coupling calculation methodology for the launch dynamics of a self-propelled artillery multibody system.This method leverages the ABAQUS subroutine interface VUAMP to compute the dynamic response of the projectile and barrel during the launch process of large-caliber self-propelled artillery.Additionally,it examines the changes in projectile resistance and band deformation in relation to projectile motion throughout the band engraving process.Comparative analysis of the computational outcomes with experimental data evidences that the proposed method offers a more precise depiction of the launch process of self-propelled artillery,thereby enhancing the accuracy of launch dynamics calculations for self-propelled artillery.

Application of Choquet Integral-Importance-Performance Analysis and TOPSIS Methods in Approaching the Preference Factors of Calligraphy and Seal Engraving Imagery

Classical Chinese characters,presented through calligraphy,seal engraving,or painting,can exhibit different aesthetics and essences of Chinese characters,making them the most important asset of the Chinese people.Calligraphy and seal engraving,as two closely related systems in traditional Chinese art,have developed through the ages.Due to changes in lifestyle and advancements in modern technology,their original functions of daily writing and verification have gradually diminished.Instead,they have increasingly played a significant role in commercial art.This study utilizes the Evaluation Grid Method(EGM)and the Analytic Hierarchy Process(AHP)to research the key preference factors in the application of calligraphy and seal engraving imagery.Different from the traditional 5-point equal interval semantic questionnaire,this study employs a non-equal interval semantic questionnaire with a golden ratio scale,distinguishing the importance ratio of adjacent semantic meanings and highlighting the weighted emphasis on visual aesthetics.Additionally,the study uses Importance-Performance Analysis(IPA)and Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)to obtain the key preference sequence of calligraphy and seal engraving culture.Plus,the Choquet integral comprehensive evaluation is used as a reference for IPA comparison.It is hoped that this study can provide cultural imagery references and research methods,injecting further creativity into industrial design.

Dynamic analysis of a guided projectile during engraving process

The reliability of the electronic components inside a guided projectile is highly affected by the launch dynamics of guided projectile.The engraving process plays a crucial role on determining the ballistic performance and projectile stability.This paper analyzes the dynamic response of a guided projectile during the engraving process.By considering the projectile center of gravity moving during the engraving process,a dynamics model is established with the coupling of interior ballistic equations.The results detail the stress situation of a guided projectile band during its engraving process.Meanwhile,the axial dynamic response of projectile in the several milliseconds following the engraving process is also researched.To further explore how the different performance of the engraving band can affect the dynamics of guided projectile,this paper focuses on these two aspects:(a) the effects caused by the different band geometry;and(b) the effects caused by different band materials.The time domain and frequency domain responses show that the dynamics of the projectile are quite sensitive to the engraving band width.A material with a small modulus of elasticity is more stable than one with a high modulus of elasticity.

CCOC：An Optimizing Compiling System for Concurrent C Supporting Inter－process Code Analysis and Optimization

At present, there are some static code analyses and optimizations that can be applied to Concurrent C programs to improve their performance or verify their logical correctness. These analyses and optimizations are inter-process. In order to make their implementation easy, we propose a new method to construct an optimizing compiling system CCOC for Concurrent C. CCOC supports inter-process code analysis and optimization to Concurrent C programs and does not affect the system's portability and separate compilation of source programs. We also discuss some implementation details of CCOC briefly.

Numerical simulation of the coupled dynamics model of the projectile engraving process

The projectile engraving process directly influences the projectile motion in-bore and impacts the firing accuracy,firing safety,and barrel life of the gun.For this reason,attention has been focused on this research topic.To address the limitations of the“instantaneous engraving”hypothesis adopted in the classical interior ballistic theory,the VUAMP user subroutine,one of ABAQUS's secondary development interfaces,is utilized in this paper to realize the modeling and numerical simulation of a coupled dynamics model of the projectile engraving process.In addition to facilitating engineering applications,a polynomial fitting formula of the engraving resistance obtained by simulation is proposed and then used as a supplement to establish a closed and solvable interior ballistic model considering the projectile engraving process.By comparing with test data,the simulation accuracy of the coupled dynamics model is verified.Simulation results reveal that the engraving process takes 3.8 ms,accounting for 26%of the whole launch process,which takes 14.6 ms,demonstrating that the process is not instantaneous.The results of this paper can serve as a reference for future studies on the coupled solution of the projectile engraving process and interior ballistics of guns or gun-like equipment.

A High Speed Signal Processing Machine -Its Architecture, Language and Compiler

A systolic array architecture computer (FXCQ) has been designed for signal processing. R can handle floating point data at very high speed. It is composed of 16 processing cells and a cache that are connected linearly and form a ring structure. All processing cells are identical and programmable. Each processing cell has the peak performance of 20 million floating-point operations per second (20MFLOPS). The machine therefore has a peak performance of 320 M FLOPS. It is integrated as an attached processor into a host system through VME bus interface. Programs for FXCQ are written in a high-level language -B language, which is supported by a parallel optimizing compiler. This paper describes the architecture of FXCQ, B language and its compiler.

统计活动过程视角下小学“统计与概率”教材内容的分析与比较——以“苏教版”“北师版”为例

以“统计活动过程”视角为理论基础,从统计活动过程的各环节要素对苏教版和北师版小学数学教材中“统计与概率”内容进行分析和比较.研究发现:两版教材在统计活动过程的各环节上有所侧重,整体上各具风格;两版教材均直接突出对统计基础知识的重视,并间接蕴涵着对数据意识的培养.对教材使用的启示有:以“统计活动视角”为基础,注重对教材进行创生;将活动视角与统计教学间的“冲突”化为提升素养的机会;进而在统计活动中促进批判性思维的发展.对教材编写或修订提供启发:从学科角度厘清“统计”与“概率”的本质关系,整体把握统计活动的全过程,给予学生更多获取直接经验的机会.

职业院校开发新形态教材实践与探索

教材建设要以学生为中心,注重教材形式、内容、使用方式的灵活性,强调立德树人、凸显职业教育特色.根据科学的教材开发思路与开发流程编写教材,教材形式上采用“活页”呈现,内容主要包括:学习情境描述、学习目标、学习任务书、引导问题、相关知识、任务实施、成果展示与评价反馈、巩固与拓展练习等,编写真正符合职业院校教学需要的新形态教材,以推进职业教育进一步发展.

现代火炮内弹道面临的问题与对策

从现代火炮及弹药技术的发展趋势,分析了火炮内弹道面临的问题,阐述了火炮内弹道理论与技术的发展方向,集中体现在三个方面,一是提高常规固体发射药火炮的作战效能;二是发展与制导弹药等特种弹药发射方式相适应的内弹道理论与控制技术;三是研究新能源火炮的内弹道理论与控制技术。在此基础上,结合国内外研究状况,对若干重点问题进行了述评,并提出了研究对策。

某小口径火炮弹丸挤进过程动力学特性分析

为研究某小口径火炮不同坡膛结构下弹丸挤进过程的动力学特性,建立了考虑挤进阻力变化的内弹道方程组并通过vuamp子程序引入到有限元求解中,实现了挤进过程中内弹道计算与弹丸挤进有限元仿真耦合求解。通过对弹丸全膛运动的仿真分析验证了模型的可行性,随后得到并分析不同坡膛锥度、膛线深度及阴线宽度下挤进过程中弹丸的速度、加速度、挤进阻力和膛压曲线及变化影响规律。结果表明,坡膛锥度对挤进过程中弹丸的动力学参数影响不是单调的,而膛线深度及阴线宽度的改变则单调地影响弹丸动力学参数,对优化坡膛结构及弹带设计具有一定的指导意义。

尼龙-紫铜复合弹带结构设计及动态挤进特性分析

针对大口径火炮在弹带挤进阶段由于应力过大易对炮膛内壁造成损伤的问题,以大口径火炮发射过程的内弹道特性为背景,展开尼龙-紫铜复合弹带的结构设计及其动态挤进过程的数值仿真研究。基于现有紫铜材质弹带,通过注塑工艺制备一种尼龙-紫铜复合结构弹带,降低挤进过程中的弹带应力。利用经典内弹道方程组求解内弹道过程中弹丸弹底压力变化,并作为动力条件展开动力学分析,使用单一及复合材质弹带的弹丸挤进过程中的内弹道动力学参数,分析尼龙厚度对复合弹带性能的影响。研究发现,相比于紫铜弹带弹丸,相同条件下使用尼龙弹带的弹丸内弹道动力学参数更高,而挤进终点时刻弹带应力更低;对于使用复合结构弹带的弹丸而言,其内弹道性能和弹带尼龙含量相关。复合弹带尼龙厚度越厚,则挤进过程中弹丸内弹道动力学参数越高,而挤进终点时刻弹带应力越低。相关研究可为中大口径火炮弹带设计提供一定参考。

基于动网格的液压活塞二级缸动态压缩性能

为了研究液压活塞压缩机压缩气体的动态压缩过程,探究压缩机结构参数与压缩机压缩性能的关系,以撬装式井口天然气回收处理系统的液压活塞式压缩机二级缸为研究对象,基于液压活塞式压缩机二级缸工作原理,将仿真过程划分为3个阶段分步模拟,借助Fluent软件,结合动网格和UDF(user defined functions)编译进行仿真分析,明确了二级缸内天然气的动态压缩过程,并将活塞运动作为压缩机压缩性能的评判指标,得到了二级缸结构参数对压缩机压缩性能的影响。研究表明:工作行程和下气缸出口分布与压缩性能关系不大,而下气缸出口大小的增大对压缩性能有较大提升,范围内最大增幅47.6%。相关研究为液压活塞式压缩机的优化与设计提供一定的参考。

基于不完全匹配的掩膜版进行芯片套刻的校准方案

提出一种校准方案,在套刻曝光一般步骤的基础上进行适当调整,用不完全匹配的掩膜版同样能够实现准确的套刻曝光。研究为提高芯片制备效率、保证对准精度提供了新思路。

《玉台新咏》编撰者新考

中国文学史上的著名经典《玉台新咏》的编撰者为徐陵,自唐以来似乎已成定论。21世纪初中国当代著名文学史专家章培恒先生提出新的见解,认为《玉台新咏》实为张丽华所“撰录”(编撰)。这一新观点引起了学术界的广泛关注,众说纷纭。《玉台新咏》的“编辑”过程是非常复杂的。这个过程甚至可以说是一个浩大的工程,它可以划分为几个阶段,而在不同的阶段有不同的人参与,《玉台新咏》的“编辑”是集体合作的成果。《玉台新咏》的编辑者是徐陵,“丽人”是“撰录”者,“高楼红粉”是校对者。《玉台新咏》除了《玉台新咏序》之外,还有“小序”,即编撰者为诗集中的个别诗篇所加的序言。“小序”乃是考证《玉台新咏》编撰人的重要“内证”。

人工智能教育立法:基于教育法典的体系化编纂路径

人工智能在赋能教育的同时,也显著提升了教育立法的难度。相比于教育单行法,作为教育领域“根本法”的教育法典将能够对人工智能教育应用展开最为周延科学的规范,助益人工智能教育应用的健康发展。作为体系型法典,教育法典必然采用“总分架构”。教育法典中人工智能立法可通过总则的“在线教育”“法律责任”以及分则的相关编章进行体系化编纂。首先,教育立法的核心及编纂主线是保障公民的受教育权,故教育法典分则相关编章需分别为政府及学校设定人工智能教育资源普惠性的促进义务,使教育主体能平等享有人工智能的教育红利。其次,针对人工智能教育应用可能引发的风险,教育法典可在总则“在线教育”章,一方面引入技术性正当程序,设定算法和数据的透明义务和审计义务,以及教育标准事务不得自动化决策义务等,明确教师使用人工智能的行为规范与专业操守;另一方面,依托敏捷治理手段,构筑多元主体参与的事前监测预警平台、事中快速响应的因应机制、事后动态完善的持续发展机制,应对人工智能教育应用未知风险。最后,为了确保义务条款得以顺利实施,教育法典可在总则“法律责任”章通过引致性条款与具体责任条款的妥适选用,构筑健全的人工智能教育应用法律责任机制。

基于FPGA的VPX型智能加速模块的设计与实现

针对航空航天领域中智能计算单元运行环境恶劣、智能算法推理速度要求高以及模型部署过程复杂的问题,设计并实现了一种基于国产现场可编程门阵列(FPGA)的智能加速模块。该加速模块接口符合高速串行总线标准(VPX)规范,具有较好的机械结构和环境适应性,支持深度学习目标检测等算法的推理加速。在FPGA芯片、DDR内存、电源转换模块等核心元器件的硬件选型符合国产化要求的基础上,完成硬件电路设计,得到智能加速模块实物。以目标检测算法为例,使用设计的自动编译工具将权重文件和模型文件部署到智能加速模块上进行推理计算,实验证明了智能加速模块具有较好的环境适应性、部署便捷性以及计算加速性能,且加速比约为国产中央处理器(CPU)的4.47倍。

《补续高僧传》文本疏误辨考

明河历尽艰辛,撰成《补续高僧传》书稿二十六卷,有功僧史研究匪浅,也难免存在一些疏误。将《补续高僧传》文本与明河所据原始材料比勘,可以发现《补续高僧传》存在节略不当、系年疏误、采择不精、曲笔讳饰等明河编撰之失。《补续高僧传》仅有毛晋刻本存世,用他书对其进行校勘,可纠正其讹文、脱文、衍文、倒文等毛晋刊本之误。

黑色PA6材料的激光标记性能

为研究黑色尼龙6(PA6)材料的激光标记性能,以PA6为基体树脂,炭黑为着色剂和激光吸收助剂,通过双螺杆挤出机熔融共混制备黑色PA6材料。使用光纤激光打标机对黑色PA6材料进行激光标记,通过分光光度仪测试未标记与已标记区域色差△L值和肉眼观察评价黑色PA6材料的标记效果。研究了不同炭黑添加量和炭黑粒径对PA6材料黑度和激光标记效果的影响,同时研究激光标记工艺对黑色PA6材料激光标记效果的影响。结果显示:随炭黑含量的增加,PA6材料黑度L值先越来越小后趋于平衡,而激光标记效果先逐渐变好,再慢慢变差,炭黑的最优添加量在0.1%~0.2%;随炭黑粒径的增加,黑色PA6材料的黑度L值先变小后变大,激光标记效果△L值先变好后变差,炭黑添加量越多,粒径的影响就越小;激光标记仪的工艺参数(速度、功率、频率)影响黑色PA6材料的激光标记效果,其中速度和功率的影响最大;炭黑添加质量分数为0.1%时,速度、功率对激光标记效果的影响最敏感,工艺调整空间大,而炭黑的添加量多时,工艺对黑色PA6材料的激光标记敏感度降低。

图书馆采编流程标准化的建设路径及实践策略

图书馆丰富的馆藏资源,彰显了地区文化底蕴,为国民素质的提升起到了积极作用。图书馆采编是实现图书馆馆藏资源建设的主要形式,对图书馆服务形式以及服务体系的建设起到重要作用。本文对图书馆标准化采编流程的建设路径和标准化图书采编的实践策略进行了研究分析,旨在为图书馆管理流程的优化提供参考。

数控雕刻镶嵌工艺在台球杆加工中的应用

台球杆是台球运动的关键击球工具,性价比高、外形美观的球杆无疑更受台球爱好者的喜爱。目前,传统的台球杆后肢多采用纯手工雕刻技艺、丝印技术、激光成图技术等加工方式,无论从生产效率还是个性化要求上,都难以满足人们对台球杆后肢外观精美度的要求。为解决这些问题,在传统球杆优良制作工艺的基础上,研究改良球杆后肢美观设计及其加工工艺,运用先进的CAD/CAM软件技术进行图形绘制,再进行刀具路径参数设置并生成刀具加工路径,输出NC代码,通过CNC数控雕刻设备完成图案雕刻,结合完美的手工镶嵌工艺,完成台球杆后肢加工。大量加工实例验证表明,所提出的加工方法可以让台球杆后肢美观度得到进一步提高,使球杆在保证高性能的同时成为一件艺术品。