Microscopic Mechanism of the ω Variation in Moments of Inertia for the Yrast Superdeformed Bands 194Tl(1a, 1b)

The variation in moments of inertia (J(1) and J(2)) with rotational frequency for the superdeformed bandsin odd-odd nuclei, 194Tl(la,lb), is investigated by using the particle-number conserving method for treating the pairinginteraction (monopole and quadrupole). The observed variations of J(1) and J(2) with ω are reproduced quite well inthe calculation and the contributions from each major shell are clearly displayed.

Determining the moment of inertia of triaxial Mars with updated global gravity models

The principal moments of inertia(PMIs)with the principal axes are usually taken as the dynamic figure parameters of Mars;they can be deduced from satellite-observed degree-two gravitational potentials in recent global gravity models and from the dynamic ellipticities resulting from precession observations.These PMIs are natural and significant for the geodetic,geophysical,and geodynamic problems of Mars,which are functions of internal density distributions.In this study,a closed and concise formula for determining the PMIs of the entire planet and its core was developed based on the second invariants of gravity and a multipole expansion.We deduced the polar oblateness J^(2)and the equatorial ellipticity J_(22)of Mars to be 1.9566×10^(−3)and 6.3106×10^(−5),respectively.The preferred principal moments of inertia of Mars are A=2.66589×1036 kg·m^(2),B=2.66775×10^(36)kg·m^(2),and C=2.68125×10^(36)kg·m^(2).These values indicate that Mar is slightly triaxial.The equatorial principal moment of inertia of the Martian core is 1.46008×10^(35)kg·m^(2),accounting for~5.47%of the planet’s PMI;this result is critical for investigating the density and size of the core of Mars,and the planet’s free core nutation.

Coupling Analysis of Moment of Inertia & Dynamic on Optoelectronic Tracking Turntable

With photoelectric tracking system as the research object,based on the theorem of moment of momentum and Euler dynamic equation,Nonlinear biaxial coupling dynamic model of tracking turntable is established.Effects of moment of inertia coupling,speed coupling and the dynamic coupling between tracking turntable shafts were studied,the analytical relation between them was given in theory.Verify the change trend of theoretical model.And it provides the theory reference and model base,for the future design of the high precision tracking controller And control parameter selection and optimization.In the end,specific measures are made for structure optimization.

The principal moments of inertia calculated with the hydrostatic equilibrium figure of the Earth

As an indication of the Earth＇s mass distribution, the principal moments of inertia （PMOI, i.e., A, B, C） of the Earth are the basic parameters in studies of the global dynamics of the earth, like earth nutation, and the geophysics. From the aspect of observation, the PMOI can be calculated from the spherical coefficients of observed gravity field. In this paper, the PMOI are calculated directly according to its definition with the figures of the Earth＇s interior derived by a generalized theory of the hydrostatic equilibrium figure of the Earth. We obtain that the angle between the principal axis of the maximum moment of PMOI and the rotational axis is 0.184~, which means that the other two principal axes are very closely in the equatorial plane. Meanwhile, B-A is 1.60 x 10-5 MR2, and the global dynamical flattening （H） is calculated to be 3.29587 ~ 10-3, which is 0.67% different from the latest observation derived value Hobs（3.273795 × 10 ^-3） （Petit and Luzum, 2010）, and this is a significant improvement from the 1.1% difference between the value of H derived from traditional theories of the figure of the Earth and the value of Hobs. It shows that we can calculate the PMOI and H with an appropriate accuracy by a gener- alized theory of the hydrostatic equilibrium figure of the Earth.

The Steiner Formula and the Polar Moment of Inertia for the Closed Planar Motions in Complex Plane

In this paper, the Steiner area formula and the polar moments of inertia were expressed during one-parameter closed planar motions in complex plane. The Steiner points or Steiner normal concepts were described according to whe-ther rotation number was different from zero or equal to zero. The moving pole point was given with its components and its relation to the Steiner point or Steiner normal which was specified. The Steiner formula and the polar moments of inertia were expressed for the inverse motion. The fixed pole point was calculated for the inverse motion. The sagittal motion of a tele-scopic crane was considered as an example. This motion was described by a double hinge consisting of the fixed control panel of the telescopic crane and its moving arm. The results obtained in the first section of this study were applied to this motion.

Systematic study of kinematic and dynamic moments of inertia of superdeformed bands with NpNn scheme

The systematics of kinematic moment of inertia J and dynamic moment of inertia J of superdeformed（SD） bands in A -130, 150, 190 mass regions have been studied. We have obtained the values of J^（1） and J^（2）for all the SD bands observed in the A-130, 150, 190 mass regions by using the experimental intraband E2 transition energies. The result of this work includes the variation of J with the product of valence proton and neutron numbers（NpNn）. The phenomenon of band mixing has been observed in the A -130, 150 mass regions and band crossing has been observed in the A-190 mass region. The systematics also includes the variation of J with the product of valence proton and neutron numbers（NpNn）. Evidence of staggering behaviour has been observed in all three A-130, 150 and 190 mass regions. We present for the first time the variation of J^（1）and J^（2）of SD bands in the A-130, 150, 190 mass regions with NpNn.

Description of the Superdeformed Bands of the Odd-Odd Nuclei in A ～ 150 Region

With the supersymmetry scheme including many-body interactions, the global property and the △I ＝ 4bifurcation in the superdeformed (SD) bands of odd-odd nuclei in A ～ 150 mass region are investigated systematically.Good results for the γ-ray energies, the dynamical moments of inertia, and energy differences △ Eγ - △ Erefγ are obtained.It shows that this approach is quite powerful in describing not only the SD bands in even-even and odd-A nuclei butalso those in odd-odd nuclei in the mass region.

Description of Rotation Bands in ^(157,158)Er at Ultrahigh Spin

Properties of the four rotation bands, ^157Er（1,2） and ^15SEr（1,2）, at ultrahigh spin are investigated within the supersymmetry scheme including many-body interactions and possessing the SO（5） （or SU（5）） symmetry on the rotational symmetry. Quantitatively good results of the 7-ray energies and the dynamical moments of inertia in the rotation bands in ^157 Er and ^158 Er at ultrahigh spin are obtained. We theoretically predict that the competition between the anti-pairing and pairing effects may exist in ^157 Er（1,2） and ^158Et（2） bands states. In ^158Er（1） band state, the favourepairing effects may exist and the SO（5） （or SU（5）） symmetry play a dominant role. There may be sphere coexisting with headecupole deformed in ^158Et（1） rotation band state.

Systematic Study on Triaxial Superdeformed Bands of Hf Isotopes

Properties of the triaxiai superdeformed （TSD） bands of Hf isotopes are investigated systematicaily within the supersymmetry scheme including many-body interactions and a perturbation possessing the SO（5） （or SU（5）） symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia, and the spin of the TSD bands in Hf isotopes are obtained. It shows that this approach is quite powerful in describing the properties of the triaxial superdeformation in Hf isotopes.

Description of Properties of Triaxial Superdeformed Bands in Odd-A Lu Isotopes

Properties of the triaxial superdeformed （TSD） bands of odd-A Lu isotopes are investigated systematically within the supersymmetry scheme including many-body interactions and a perturbation possessing the S0（5） （or SU（5）） symmetry on the rotational symmetry. Quantitatively good results of the γ-ray energies, the dynamical moments of inertia and the spin of the TSD bands in odd-A Lu isotopes are obtained. The calculation shows that the competition between the pairing and anti-pairing effects exists in these TSD bands. Meanwhile, the SU（3） symmetry in TSD bands are broken more seriously than in superdeformed （SD） bands.

Description of the Superdeformed Bands of Odd-Odd Nuclei in A～80 Region

Properties of the superdeformed bands of odd-odd nuclei in A ～ 80 massregion are investigated system-atically within the supersymmetry scheme including many-bodyinteractions and a perturbation possessing the SO(5) (or SU(5)) symmetry on the rotational symmetry.The obtained γ-ray energies, and the dynamical moments of inertia agree with experimental data. Itshows that this approach is quite powerful in describing odd-odd nuclei in A ～ 80 mass region.

Three approaches to assign the spins of rotational bands

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Tensors of Rank Two in Tensor Flight Dynamics

Tensor flight dynamics solves flight dynamics problems using Cartesian tensors, which are invariant under coordinate transformations, rather than Gibbs’ vectors, which change under time-varying transformations. Three tensors of rank two play a prominent role and are the subject of this paper: moment of inertia, rotation, and angular velocity tensor. A new theorem is proven governing the shift of reference frames, which is used to derive the angular velocity tensor from the rotation tensor. As applications, the general strap-down INS equations are derived, and the effect of the time-rate-of-change of the moment of inertia tensor on missile dynamics is investigated.

刚体转动惯量实验的改进

动力学法测刚体转动惯量是通过测量砝码脱落前后2π~6π角位移区间的角加速度平均值得到转动惯量,该实验要求砝码脱落前后系统为匀变速运动,但该前提条件并不能得到很好保证,从而引入了系统误差.本文利用黑白条码纸带、光纤放大器、数据采集卡等对实验装置进行了改进,同时优化了数据处理方法,减弱了对匀变速运动这一前提的要求.对照实验测量结果表明:改进后的实验装置的测量误差减小,对平行轴定理的验证效果得到了提升.

冰冻地球的进动与章动

基于贾尼别科夫效应网上流传的一些观点认为,当地球南北两极的海冰增加或者减少将导致地球重量分布不平衡,地球将会发生翻转.本文基于简单的刚体地球模型,首先计算了地球南北纬度结冰时导致的地球总转动惯量变化,并利用欧拉动力学方程分析转动惯量变化引起的地球的进动与章动.研究指出,不论是不受外力作用的潘索情况还是考虑了潮汐力的情况,地球在南北纬度30°结冰的情况下旋转最不稳定.此外,即使地球表面冰冻到深度33公里,贾尼别科夫效应也不会在地球上发生.通过本文简单的计算终结了网络流言,并且有利于人们对地球进动和章动的理解.

基于CFD变形网格法的螺旋桨水中附加转动惯量研究

为了在螺旋桨设计中较为准确地估算螺旋桨在水中的附加转动惯量,为轴系设计提供更为准确的设计输入,并进一步探究螺旋桨设计参数对于附加转动惯量的影响规律,以通用计算流体力学(CFD)软件STAR-CCM+为平台,运用内置的变形网格技术,以某油船螺旋桨为研究对象,进行基于RANS方程全粘流的附加转动惯量数值计算研究。在此基础上,通过参数变换获取两组弦长和螺距等比例变化的螺旋桨模型,计算其附加转动惯量并分析和设计参数之间的关系。结果表明:对于同一弦长分布的桨,附加转动惯量占比(水中附加转动惯量除以自身转动惯量)随螺距的增加而增加;对于同样螺距分布的桨,附加转动惯量占比随弦长的增加而减小。通过回归分析,建立螺旋桨水中附加转动惯量与弦长及螺距的回归模型,实现了设计中的快速预报。

弹射过程人椅系统动态质量特性的建模与分析

人椅系统的质量特性是弹射座椅轨迹和姿态控制精度的重要影响因素。由于缺乏动态质量特性仿真模型,现阶段采用静态参数设计的弹射座椅控制规律可能在实际应用中出现偏差。本文在弹射座椅六自由度运动模型的基础上,考虑火箭包工作质量变化、人体脊柱压缩、座椅座垫压缩和人体头颈部转动等影响因素,建立了弹射过程人椅系统动态质量特性的计算模型。通过对三个典型工况计算结果的分析,说明了计算模型的合理性;最后分别采用动态、静态质量特性模型对弹射过程轨迹姿态进行仿真,并分析了两模型在救生效果上的差异性。本文建立的模型可以为后续弹射座椅控制规律的精细化设计提供借鉴。

基于阿基米德螺旋的软爪车削卡箍设计与应用

以软爪的传统加工工艺为基础,运用阿基米德螺旋原理,增大螺旋曲线向量半径,设计一种以自身惯性力大自锁夹紧的软爪车削夹具。介绍该夹具的设计方法、结构构造及使用方法。经实践使用表明:该夹具操作灵活,加工精度高,有效提高了零件的定位基准和加工质量。

The Vibration of Partially Filled Cylindrical Tank Subjected to Variable Acceleration

In this study, the vibration of a cylindrical tank partially filled with liquid under motion modeled as mass lumped is investigated. A three-dimensional quasi-static model of a partially-filled tank of circular cross-section is developed and integrated into a comprehensive three-dimensional vehicle model to study its dynamic performance as a function of acceleration, and the fill volume. The liquid load movement occurring in the roll and pitch planes of the tank is derived as a function of the longitudinal acceleration, and then the corresponding shifted load is expressed in terms of center of mass coordinates and mass moments of inertia of the liquid bulk, assuming negligible influence of fundamental slosh frequency and viscous effects. The vibration characteristics of the partially filled tank vehicle are evaluated in terms of load shift, forces and moments induced by the cargo movement, and dynamic load transfer in the longitudinal direction. The semi analytical response is obtained by means of SimuLink? Matlab Software. The effects of longitudinal acceleration of the tank system on the liquid surface inclination and consequently shifting of centroids and moment of inertia are illustrated.

On the Kinematics for the Closed Planar Homothetic Inverse Motions in Complex Plane

In this paper, the Steiner area formula and the polar moment of inertia were expressed during one-parameter closed planar homothetic inverse motions in complex plane. The Steiner point was defined when the rotation number was different zero and it was called the Steiner normal when the rotation number was equal to zero. The fixed pole point was given with its components and its relation between Steiner point or Steiner normal was explained. The sagittal motion of a telescopic crane was considered as an example. This motion was described by a double hinge consisting of the fixed control panel of the telescopic crane and the moving arm of the telescopic crane. The theoretical concepts and results were applied for this motion.