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3-D有限元转子模型减缩的旋转子结构法 被引量:9
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作者 左彦飞 王建军 马威猛 《航空动力学报》 EI CAS CSCD 北大核心 2014年第4期894-900,共7页
为了对3-D有限元转子模型进行减缩,利用Guyan减缩法的基本原理,结合转子动力学分析理论,提出了易于实际应用的减缩方法——旋转子结构法并利用ANSYS程序将其实现.利用该方法减缩了某涡扇发动机转子模型21%的自由度数.减缩模型前20阶最... 为了对3-D有限元转子模型进行减缩,利用Guyan减缩法的基本原理,结合转子动力学分析理论,提出了易于实际应用的减缩方法——旋转子结构法并利用ANSYS程序将其实现.利用该方法减缩了某涡扇发动机转子模型21%的自由度数.减缩模型前20阶最大固有频率百分误差为0.43%,除第17阶振型置信因子为0.98外,其余振型置信因子均为1,临界转速计算的最大误差为0.46%.计算结果证明该方法是可行的. 展开更多
关键词 旋转子结构 陀螺效应 3-D有限元 模型减缩 转子动力学
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采用复约束旋转模态子结构法分析离心叶轮振动特性
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作者 邱凯 徐自力 王尚锦 《西安交通大学学报》 EI CAS CSCD 北大核心 1999年第5期33-37,共5页
根据叶轮周向循环对称的特点,采用回转周期结构的复约束及旋转模态子结构方法,将计算简化为针对一个叶道进行,从而达到降阶的目的.为了解决采用复约束而出现的广义复Hermite矩阵特征值问题,提出了一个改进的子空间迭代方法... 根据叶轮周向循环对称的特点,采用回转周期结构的复约束及旋转模态子结构方法,将计算简化为针对一个叶道进行,从而达到降阶的目的.为了解决采用复约束而出现的广义复Hermite矩阵特征值问题,提出了一个改进的子空间迭代方法,并对Jacobi迭代作出了相应的修改.最后,用该模型对一个实际离心叶轮振动特性进行了分析。 展开更多
关键词 离心叶轮 振动 旋转模态子结构 离心压式压缩机
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旋转对称子结构罚单元分析
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作者 李香莲 《航空发动机》 2004年第4期34-37,共4页
叙述了罚单元法和罚单元刚度矩阵的推导过程。列举了应用罚单元法处理旋转对称子结构边界位移协调和不同类型单元连接点位移协调的实例 。
关键词 旋转对称子结构 罚单元 线性约束 刚度矩阵
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Nucleon Spin Structure Functions in the Resonance Region and the Duality
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作者 DongYu-Bing FENGQing-Guo 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第6期675-680,共6页
We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structur... We discuss the nucleon spin structure function g<SUB>1</SUB> and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structure function is also analyzed. Effects of the Δ(1232) and Roper P<SUB>11</SUB>(1440) resonances on the spin structure function and on the difference are mentioned. The results of different models for the Roper resonance are also addressed. 展开更多
关键词 constituent quark model quark-hadron duality nucleon spin structure function Roper resonance
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Ab initio Study of Electronic Structure and Magnetic Properties of Two Novel Neptunium (V) Sulfates: iaK3(ipO2)4(SO4)4(H2O)2 and iaipO2SO4H2O
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作者 ZHU Lin YAO Kai-Lun LIU Zu-Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第5X期921-924,共4页
Ab initio within the full potential linearized augmented plane wave (FP-LAPW) method with the GGA+U approach is applied to study the electronic structures of two compounds NaK3(NpO2)4(SO4)4(H2O)2 and NaNpO2SO... Ab initio within the full potential linearized augmented plane wave (FP-LAPW) method with the GGA+U approach is applied to study the electronic structures of two compounds NaK3(NpO2)4(SO4)4(H2O)2 and NaNpO2SO4H2O. The present calculations show that the major part of the spin magnetic moment in these two compounds is from Np(V) ions, and the origin of the cation-cation interactions between Np comes from the spin polarization effect within Np-ONv-Np bonds. 展开更多
关键词 ab initio electronic structure FERROMAGNETIC spin polarization spin delocalization
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Structure of Rotating Neutron Stars in Uniform Strong Magnetic Field
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作者 WEN De-Hua CHEN Wei LIU Liang-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第4期653-657,共5页
Properties and deformations of the rotating neutron stars in uniform strong magnetic field are calculated. The magnetic field will soften the equation of state of the neutron star matters and make an obvious effect on... Properties and deformations of the rotating neutron stars in uniform strong magnetic field are calculated. The magnetic field will soften the equation of state of the neutron star matters and make an obvious effect on the structure of the rotating neutron star. If the magnetic field is superstrong (B=10^17 T), the mass, radius, and the deformation will become smaller effectively. 展开更多
关键词 STRUCTURE neutron star strong magnetic field
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Construction of some hypergroups from combinatorial structures
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作者 AliRezaAshrafi AhmadRezaEslami-Harandi 《Journal of Zhejiang University Science》 CSCD 2003年第1期76-79,共4页
Jajcay's studies( 1993 ; 1994) on the automorphism groups of Cayley maps yielded a new product of groups, which he called, rotary product. Using this product, we define a hyperoperation ⊙ on the group Syme (G) , ... Jajcay's studies( 1993 ; 1994) on the automorphism groups of Cayley maps yielded a new product of groups, which he called, rotary product. Using this product, we define a hyperoperation ⊙ on the group Syme (G) , the stabilizer of the identity e ∈ G in the group Sym (G) . We prove that ( Syme (G) , ⊙) is a hypergroup and characterize the subhypergroups of this hypergroup.Finally, we show that the set of all subhypergroups of Syme ( G ) constitute a lattice under ordinary join and meet and that the minimal elements of order two of this lattice is a subgroup of Aut (G) . 展开更多
关键词 Finite group Rotary closed subgroup HYPERGROUP Sub hypergroup Combinatorial structures
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Study on terahertz spectra of SO_2 and H_2S 被引量:3
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作者 CAI He WANG Dong SHEN JingLing 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第4期685-690,共6页
The spectral characteristics of air pollution gas sulfur dioxide and hydrogen sulfide has been studied experimentally and theo-retically in the range of 0.2-2.6 THz. The gases absorption spectra of sulfur dioxide and ... The spectral characteristics of air pollution gas sulfur dioxide and hydrogen sulfide has been studied experimentally and theo-retically in the range of 0.2-2.6 THz. The gases absorption spectra of sulfur dioxide and hydrogen sulfide, as measured by terahertz Time-Domain Spectroscopy (THz-TDS) technique, show equi-spaced absorption peaks. The peak intervals are varied for different gas and may relate with the molecule structures and rotation modes. We have calculated the intervals of rotational transition frequency according to the gases molecule structure and the rotational modes. The results are consistent with experimental results which confirm the suggestion that the absorption is coming from the molecular rotational transition. The study suggests a technique to detect air pollutants by THz-TDS and the rotational modes of gas molecules. 展开更多
关键词 SPECTROSCOPY terahertz wave rotational mode gas molecule
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Giant spin torque efficiency in single-crystalline antiferromagnet MnAu films
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作者 Shaohai Chen Xinyu Shu +6 位作者 Jing Zhou Chenghang Zhou Qidong Xie Tieyang Zhao Liang Liu Weinan Lin Jingsheng Chen 《Science China Materials》 SCIE EI CAS CSCD 2021年第8期2029-2036,共8页
Antiferromagnetic (AFM) materials have attracted wide attention in spin-orbit torque (SOT)-based spintronic due to its abundant spin-dependent properties and unique advantage of immunity against external field perturb... Antiferromagnetic (AFM) materials have attracted wide attention in spin-orbit torque (SOT)-based spintronic due to its abundant spin-dependent properties and unique advantage of immunity against external field perturbations.To act as the charge-to-spin conversion source in energy-saving spintronic devices,it is of great importance for the AFM material to possess a large spin torque efficiency(ξDL).In this work,using the spin torque ferromagnetic resonance (ST-FMR) technique and a Mn2Au/Ni Fe(Py) bilayer system,we systemically study the ξDLof AFM Mn2Au films with different crystal structures.Compared with polycrystalline Mn2Au with effective ξDL<0.051,we show a much larger ξDLof~0.333 in single-crystal Mn2Au,which arises from the large spin Hall conductivity instead of electrical resistivity.Moreover,with a further contribution of interfacial effects,the effective ξDLof single-crystalline Mn2Au/Py system increases to 0.731,which is more than two times larger than the value of ~0.22 reported for the Mn2Au/CoFeB system.By utilizing the largeξDLof Mn2Au in a perpendicularly magnetized Mn Ga/Mn2Au system,energy-efficient deterministic magnetization switching with a current density at ~10^(6)A cm^(-2)is achieved.Our results reveal a significant potential of Mn2Au as an efficient SOT source and shed light on its application in future AFM material-based SOT integration technology. 展开更多
关键词 ANTIFERROMAGNETIC spin torque efficiency electrical magnetization switching spin torque ferromagnetic resonance
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