A combined method of wave superposition and finite element is proposed to solve the radiation noise of targets in shallow sea.Taking the sound propagation of spherical sound source in shallow sea as an example,the rad...A combined method of wave superposition and finite element is proposed to solve the radiation noise of targets in shallow sea.Taking the sound propagation of spherical sound source in shallow sea as an example,the radiation sound field of the spherical sound source is equivalent to the linear superposition of the radiation sound field of several internal point sound sources,and then the radiated noise induced by spherical sound source can be predicted quickly.The accuracy and efficiency of the method are verified by comparing with the numerical results of finite element method,and the rapid prediction of underwater radiated noise of cylindrical shell is carried out based on the method.The results show that compared with the finite element method,the relative error of the calculation results under different simulation conditions does not exceed 0.1%,and the calculation time is about 1/10 of the finite element method,so this method can be used to solve the radiated noise of shallow underwater targets.展开更多
Spinodal phase separation behavior of poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN) blends was investigated by the time-resolved small angle light scattering (SALS) technique. It was found that t...Spinodal phase separation behavior of poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN) blends was investigated by the time-resolved small angle light scattering (SALS) technique. It was found that the influence of temperature on the scattering intensity evolution followed the time-temperature superposition principle. The relationship between temperature and the relaxation ti me of scattering intensity I(t) can be well described by the Williams-Landel-Ferry (WLF) function.展开更多
The paper presents general description of combined structural system and initial analysis of an innovative system proposed as the main support structure for tall or heavy loaded buildings located on subsoil of very sm...The paper presents general description of combined structural system and initial analysis of an innovative system proposed as the main support structure for tall or heavy loaded buildings located on subsoil of very small load-carrying ability or in earthquake areas. Moreover there is presented also an innovative two-stage method of the approximate calculation of the statically indeterminate trusses. Both are invented by the author by application of the principles of the superposition method.展开更多
The real random number generation is a critical problem in computer science.The current generation methods are either too dangerous or too expensive,such as using decays of some radioactive elements.They are also hard...The real random number generation is a critical problem in computer science.The current generation methods are either too dangerous or too expensive,such as using decays of some radioactive elements.They are also hard to control.By the declaration of uncertainty principles in quantum mechanics,real probabilistic events can be substituted by easier and safer processes,such as electron diffraction,photon diffraction and qubits.The key to solve the problem of Schr?dinger’s cat is to identify that the atom stays in different states after and before the decay,and the result of the decay is probabilistic according to the wave packet co llapse hypothesis.Same matter is able to possess different kinds of properties such as wave-particle duality due to that it can stay in various states,and which state will the matter stay is determined by the chosen set of physical quantities(or mechanical quantities).One eigenstate of a set of physical quantities can be a superpos ition of other eigenstates of different sets of physical quantities,and the collapse from a superposition to an eigenstate it contains is really random.Using this randomness,real random number can be generated more easily.展开更多
通过准静态力学性能实验和动态热机械实验研究Q411T聚脲材料的基本力学性能和动态热机械性能;基于时温等效原理(TTS)拟合Q411T聚脲的损耗模量、储能模量主曲线,研究Q411T聚脲吸能特性。采用4 kg钢球进行落球冲击试验,通过DH5960动态信...通过准静态力学性能实验和动态热机械实验研究Q411T聚脲材料的基本力学性能和动态热机械性能;基于时温等效原理(TTS)拟合Q411T聚脲的损耗模量、储能模量主曲线,研究Q411T聚脲吸能特性。采用4 kg钢球进行落球冲击试验,通过DH5960动态信号测试分析系统采集钢板在冲击荷载作用下的应变时程曲线,分析有无防护涂层的钢板抗冲击防护效果。结果表明:Q411T型聚脲材料具有良好的力学性能和抗冲击能力,材料的玻璃化转变温度为-20℃,损耗因子的峰值为0.18,在常温状态下材料的损耗因子大于0.12,具有一定的吸能特性;落球冲击试验表明,在钢板迎撞面喷涂2 mm Q411T涂层可以有效抑制结构变形,试样挠度下降45%,钢板抗冲击性能显著提高。展开更多
基金Foundation item:This study was financially supported by the National Natural Science Foundation of China(Grant No.52101351)。
文摘A combined method of wave superposition and finite element is proposed to solve the radiation noise of targets in shallow sea.Taking the sound propagation of spherical sound source in shallow sea as an example,the radiation sound field of the spherical sound source is equivalent to the linear superposition of the radiation sound field of several internal point sound sources,and then the radiated noise induced by spherical sound source can be predicted quickly.The accuracy and efficiency of the method are verified by comparing with the numerical results of finite element method,and the rapid prediction of underwater radiated noise of cylindrical shell is carried out based on the method.The results show that compared with the finite element method,the relative error of the calculation results under different simulation conditions does not exceed 0.1%,and the calculation time is about 1/10 of the finite element method,so this method can be used to solve the radiated noise of shallow underwater targets.
基金This work was supported by the Special Funds for Major State Basic Research Projects (Grand G1999064800)
文摘Spinodal phase separation behavior of poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN) blends was investigated by the time-resolved small angle light scattering (SALS) technique. It was found that the influence of temperature on the scattering intensity evolution followed the time-temperature superposition principle. The relationship between temperature and the relaxation ti me of scattering intensity I(t) can be well described by the Williams-Landel-Ferry (WLF) function.
文摘The paper presents general description of combined structural system and initial analysis of an innovative system proposed as the main support structure for tall or heavy loaded buildings located on subsoil of very small load-carrying ability or in earthquake areas. Moreover there is presented also an innovative two-stage method of the approximate calculation of the statically indeterminate trusses. Both are invented by the author by application of the principles of the superposition method.
文摘The real random number generation is a critical problem in computer science.The current generation methods are either too dangerous or too expensive,such as using decays of some radioactive elements.They are also hard to control.By the declaration of uncertainty principles in quantum mechanics,real probabilistic events can be substituted by easier and safer processes,such as electron diffraction,photon diffraction and qubits.The key to solve the problem of Schr?dinger’s cat is to identify that the atom stays in different states after and before the decay,and the result of the decay is probabilistic according to the wave packet co llapse hypothesis.Same matter is able to possess different kinds of properties such as wave-particle duality due to that it can stay in various states,and which state will the matter stay is determined by the chosen set of physical quantities(or mechanical quantities).One eigenstate of a set of physical quantities can be a superpos ition of other eigenstates of different sets of physical quantities,and the collapse from a superposition to an eigenstate it contains is really random.Using this randomness,real random number can be generated more easily.
文摘通过准静态力学性能实验和动态热机械实验研究Q411T聚脲材料的基本力学性能和动态热机械性能;基于时温等效原理(TTS)拟合Q411T聚脲的损耗模量、储能模量主曲线,研究Q411T聚脲吸能特性。采用4 kg钢球进行落球冲击试验,通过DH5960动态信号测试分析系统采集钢板在冲击荷载作用下的应变时程曲线,分析有无防护涂层的钢板抗冲击防护效果。结果表明:Q411T型聚脲材料具有良好的力学性能和抗冲击能力,材料的玻璃化转变温度为-20℃,损耗因子的峰值为0.18,在常温状态下材料的损耗因子大于0.12,具有一定的吸能特性;落球冲击试验表明,在钢板迎撞面喷涂2 mm Q411T涂层可以有效抑制结构变形,试样挠度下降45%,钢板抗冲击性能显著提高。
