The spin-exchange relaxation-free atomic gyroscope,with its exceptionally high theoretical precision,demonstrates immense potential to become the next-generation strategic-grade gyroscope.However,due to technological ...The spin-exchange relaxation-free atomic gyroscope,with its exceptionally high theoretical precision,demonstrates immense potential to become the next-generation strategic-grade gyroscope.However,due to technological noise,there is still a significant gap between its actual precision and theoretical precision.This study identifies the key factor limiting the precision of the SERF gyroscope as coupling noise.By optimizing the detection loop structure,a distinction between the dual-axis signals'response to optical and magnetic fields was achieved-where the optical errors responded similarly,while the response to magnetic noise was opposite.Based on the differences in the optical-magnetic response of the dual-axis signals,empirical mode decomposition was used to decompose the dual-axis gyroscope signals into multiple intrinsic mode functions,and Allan deviation analysis was applied to analyze the noise characteristics of the intrinsic mode functions over various periods.This study successfully reveals that optical errors caused by thermal-optical coupling and long-period magnetic noise induced by thermal-magnetic coupling are the dominant factors limiting the long-term stability of the SERF gyroscope.Based on these analyses,the study concludes that to achieve strategic-grade precision for the SERF gyroscope,it is essential to effectively address the noise issues caused by multi-physical field couplings.展开更多
To accelerate the practicality of electromagnetic railguns,it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore damage.In this paper,a three-dime...To accelerate the practicality of electromagnetic railguns,it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore damage.In this paper,a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun,and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network(PFN)is carried out.Various test methods such as spectrometer,fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity,transient magnetic field strength and stress-strain of rail.Combining the simulation results and experimental data,the damage condition of the contact surface is analyzed.展开更多
An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in e...An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.展开更多
A simple and efficient coupled displacement field method is developed to study the large amplitude free vibration behavior of the moderately thick square plates.A single term trigonometric admissible displacement fiel...A simple and efficient coupled displacement field method is developed to study the large amplitude free vibration behavior of the moderately thick square plates.A single term trigonometric admissible displacement field is assumed for one of the variables,say,the total rotations(in both X,Y directions).Making use of the coupling equation,the spatial variation for the lateral displacement field is derived in terms of the total rotations.The coupled displacement field method makes the energy formulation to contain half the number of unknown independent coefficients,in the case of a square plate,contrary to the conventional RayleighRitz method.The lesser number of undetermined coefficients significantly simplifies the vibration problem.The expressions for the linear and nonlinear fundamental frequency parameters for the all edges simply supported moderately thick square plates are derived.The numerical results obtained from the present formulation are in very good agreement with those obtained from the existing literature.展开更多
电场耦合无线电能传输(electric-field coupled wireless power transfer,EC-WPT)系统具有耦合机构轻薄且成本低、对耦合机构之间或周围导体产生的涡流损耗小等优点,适用于电动车动态无线充电应用。该文构建一种基于分段式耦合机构的动...电场耦合无线电能传输(electric-field coupled wireless power transfer,EC-WPT)系统具有耦合机构轻薄且成本低、对耦合机构之间或周围导体产生的涡流损耗小等优点,适用于电动车动态无线充电应用。该文构建一种基于分段式耦合机构的动态EC-WPT系统,以双边LC补偿的动态EC-WPT系统为对象建立系统的数学模型,对系统的接收极板在分段式导轨上方移动时系统的输出特性进行理论推导;给出一种分段式导轨的供电切换策略;以提升系统传输性能及耦合机构抗横向偏移能力等为目标,给出一种分段式耦合机构的参数设计方法;建立系统的仿真模型对接收极板运动过程中系统的输出功率进行分析;搭建一套实验装置对所设计系统及参数设计方法的合理性进行验证。仿真和实验结果表明,接收极板在相邻两段导轨过渡区域时系统的输出功率变化趋势与理论结果一致。展开更多
基金supported by Hefei National Laboratory,Innovation Program for Quantum Science and Technology(2021ZD0300400/2021ZD0300402)the Beijing Natural Science Foundation(3252013)the China Postdoctoral Science Foundation(2024T171116).
文摘The spin-exchange relaxation-free atomic gyroscope,with its exceptionally high theoretical precision,demonstrates immense potential to become the next-generation strategic-grade gyroscope.However,due to technological noise,there is still a significant gap between its actual precision and theoretical precision.This study identifies the key factor limiting the precision of the SERF gyroscope as coupling noise.By optimizing the detection loop structure,a distinction between the dual-axis signals'response to optical and magnetic fields was achieved-where the optical errors responded similarly,while the response to magnetic noise was opposite.Based on the differences in the optical-magnetic response of the dual-axis signals,empirical mode decomposition was used to decompose the dual-axis gyroscope signals into multiple intrinsic mode functions,and Allan deviation analysis was applied to analyze the noise characteristics of the intrinsic mode functions over various periods.This study successfully reveals that optical errors caused by thermal-optical coupling and long-period magnetic noise induced by thermal-magnetic coupling are the dominant factors limiting the long-term stability of the SERF gyroscope.Based on these analyses,the study concludes that to achieve strategic-grade precision for the SERF gyroscope,it is essential to effectively address the noise issues caused by multi-physical field couplings.
文摘To accelerate the practicality of electromagnetic railguns,it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore damage.In this paper,a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun,and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network(PFN)is carried out.Various test methods such as spectrometer,fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity,transient magnetic field strength and stress-strain of rail.Combining the simulation results and experimental data,the damage condition of the contact surface is analyzed.
基金Project(21075138)supported by the National Natural Science Foundation of ChinaProject(cstc2013jcyjA10088)supported by Chongqing Natural Science Foundation,ChinaProject(KJ121311)supported by Scientific and Technological Research Program of Chongqing Municipal Education Commission,China
文摘An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.
基金JNTU-Kakinada for sponsoring the necessary economical support for presenting the paper under TEQIP2the support given by Mallareddy college of engineering and Indian national academy of engineering
文摘A simple and efficient coupled displacement field method is developed to study the large amplitude free vibration behavior of the moderately thick square plates.A single term trigonometric admissible displacement field is assumed for one of the variables,say,the total rotations(in both X,Y directions).Making use of the coupling equation,the spatial variation for the lateral displacement field is derived in terms of the total rotations.The coupled displacement field method makes the energy formulation to contain half the number of unknown independent coefficients,in the case of a square plate,contrary to the conventional RayleighRitz method.The lesser number of undetermined coefficients significantly simplifies the vibration problem.The expressions for the linear and nonlinear fundamental frequency parameters for the all edges simply supported moderately thick square plates are derived.The numerical results obtained from the present formulation are in very good agreement with those obtained from the existing literature.
文摘电场耦合无线电能传输(electric-field coupled wireless power transfer,EC-WPT)系统具有耦合机构轻薄且成本低、对耦合机构之间或周围导体产生的涡流损耗小等优点,适用于电动车动态无线充电应用。该文构建一种基于分段式耦合机构的动态EC-WPT系统,以双边LC补偿的动态EC-WPT系统为对象建立系统的数学模型,对系统的接收极板在分段式导轨上方移动时系统的输出特性进行理论推导;给出一种分段式导轨的供电切换策略;以提升系统传输性能及耦合机构抗横向偏移能力等为目标,给出一种分段式耦合机构的参数设计方法;建立系统的仿真模型对接收极板运动过程中系统的输出功率进行分析;搭建一套实验装置对所设计系统及参数设计方法的合理性进行验证。仿真和实验结果表明,接收极板在相邻两段导轨过渡区域时系统的输出功率变化趋势与理论结果一致。
