The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the dam...The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.展开更多
针对炮钢材料25Cr3Mo3NiNbZr钢,结合可控离子渗入(Programable ion permeation,PIP)与激光淬火(Laser quenching,LQ)两种工艺优势进行复合处理以提升其表面性能。试验材料经调质预处理后,先进行PIP处理,再以不同扫描速度进行激光淬火。...针对炮钢材料25Cr3Mo3NiNbZr钢,结合可控离子渗入(Programable ion permeation,PIP)与激光淬火(Laser quenching,LQ)两种工艺优势进行复合处理以提升其表面性能。试验材料经调质预处理后,先进行PIP处理,再以不同扫描速度进行激光淬火。通过金相观察、XRD分析、显微硬度测试、电化学腐蚀以及中性盐雾试验等方法表征试样性能。结果表明,在2.31~3.00 J/mm^(2)的激光能量密度扫描下,部分化合物层发生了分解,降低了表面硬度;扩散层生成含氮马氏体,次表层硬度峰值得到提高。激光扫描速度为39 mm/s(激光能量密度为2.31 J/mm^(2))时工艺最佳,此时组织细化,含氮马氏体转变较多,表层氮化物损失较少,有效缓解“蛋壳效应”。PIP/LQ复合工艺处理试样的耐腐蚀性能虽低于PIP处理试样,但仍高于未处理试样,因此,PIP/LQ复合工艺在提高炮钢材料表面性能方面具有可行性。展开更多
针对传统α能谱测量系统存在的本底噪声高、能量分辨率受限等问题,研制了基于FPGA技术的数字多道分析模块与PIPS半导体探测器相结合的新一代α能谱测量系统。该系统设计基于FPGA的多参数数字多道处理架构,利用硬件描述语言实现高速脉冲...针对传统α能谱测量系统存在的本底噪声高、能量分辨率受限等问题,研制了基于FPGA技术的数字多道分析模块与PIPS半导体探测器相结合的新一代α能谱测量系统。该系统设计基于FPGA的多参数数字多道处理架构,利用硬件描述语言实现高速脉冲幅度提取算法,开发了自适应基线恢复技术和波形动态甄别机制。实验数据表明,该系统能量分辨率最低可达到16.293 ke V@5.486 MeV(FWHM),支持8192道能谱分析,具备多探测器同步采集能力,为环境放射性监测、核安全保障、食品安全等领域的超低水平α核素分析提供了可靠的技术手段。展开更多
基金Project supported by the National Natural Science Foundation of China (No. 12272323)。
文摘The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.
文摘针对传统α能谱测量系统存在的本底噪声高、能量分辨率受限等问题,研制了基于FPGA技术的数字多道分析模块与PIPS半导体探测器相结合的新一代α能谱测量系统。该系统设计基于FPGA的多参数数字多道处理架构,利用硬件描述语言实现高速脉冲幅度提取算法,开发了自适应基线恢复技术和波形动态甄别机制。实验数据表明,该系统能量分辨率最低可达到16.293 ke V@5.486 MeV(FWHM),支持8192道能谱分析,具备多探测器同步采集能力,为环境放射性监测、核安全保障、食品安全等领域的超低水平α核素分析提供了可靠的技术手段。
