Quantization of an affinely rigid body with constraints

Discussed are some quantization problems of an affinely-rigid body with additional Weyl constraints. We investigate the systems with potential energies for which the variables can be separated. The Sommerfeld polynomial method is used to perform the quantization of such problems.     

Classical mechanics of a breathing top

We develop the classical mechanics of a breathing top and consider the left- and right-invariant actions on the configurations space SL(n,R). This model is compared with the affinely-rigid body, based on GL(n,R). Applications of the breathing top can be found in the theory of elasticity and hydromechanics.     

Deformable gyroscope in a non-euclidean space classical,non-relativistic theory

The classical mechanics of structured test particles in a manifold with affine connection is studied. Gyroscopic rotations and homogeneous deformations are taken into account as internal degrees of freedom. Hence, in addition to the orbital motion of the centre of mass, the body undergoes affine rotations about the centre (“affinely-rigid body”). Configurations of particles are described mathematically by linear frames in an underlying manifold (physical space).Symmetries of the theory are discussed and in some special cases the equations of motion are derived. The orbital motion is found to be influenced by internal degrees of freedom which are dynamically coupled to the geometry of the manifold. For example, in a Riemann-Cartan space ([4], [8], [9], [25]), internal degrees of freedom interact with curvature and torsion tensors. Imposing then some holonomic constraints (orthonormal frames only), one gets the theory of test rigid bodies in a curved space with torsion. In a Riemannian case (no torsion) such a theory seems to coincide with non-relativistic (although spatially non-Euclidean) limit of theories studied by Dixon, Künzle, Tulczyjew and Papapetrou [5], [13], [26], [15].As for all standard techniques and notations of differential geometry, we follow mainly Kobayashi-Nomizu [12] and Sternberg [23].     

Field of linear frames as a fundamental self-interacting system

We present some philosophical and physical arguments supporting the hypothesis that the most fundamental self-interacting field in an amorphous space-time is the field of linear frames, i.e. the quadruple of vector bosons. We construct a wide class of Lagrangian dynamical models invariant under the total group of diffeomorphisms and under the natural action of the proper linear group GL⁺ (4, R) on the tetrad field. There exist some links between these models and the Hamiltonian dynamical systems on GL⁺ (3, R) (the mechanics of affinely-rigid bodies [23] [27]). We present the general form of field equations, conservation laws and Bianchi identities. There exist some formal similarities between our Lagrangians and those used in non-linear electrodynamics, in particular in the Born–Infeld theory [21]. We also give a few rough remarks concerning models invariant under natural subgroups of GL⁺ (4, R), i.e. under SL(4, R) and SO(1, 3; R) (special linear group and Lorentz group). The latter class includes the conventional Einstein relativity and the more general metrical-parallelism models. It turns out that there are GL⁺ (4, R)-invariant Lagrangians which are structurally alike the conventional Einstein Lagrangian.We have not derived as yet either mathematical or physical consequences of the presented model. Nevertheless, it seems to follow from our discussion that, a priori, the GL⁺ (4, R)-invariant tetrad models could be competitive with the Einstein theory. The next thing to be done would be a careful mathematical analysis of these models and attempts to compare their consequences with those of the Einstein relativity and of other field theories.     

Compensation of body shake errors in terahertz beam scanning single frequency holography for standoff personnel screening

In the terahertz(THz) band, the inherent shake of the human body may strongly impair the image quality of a beam scanning single frequency holography system for personnel screening. To realize accurate shake compensation in imaging processing, it is quite necessary to develop a high-precision measure system. However, in many cases, different parts of a human body may shake to different extents, resulting in greatly increasing the difficulty in conducting a reasonable measurement of body shake errors for image reconstruction. In this paper, a body shake error compensation algorithm based on the raw data is proposed. To analyze the effect of the body shake on the raw data, a model of echoed signal is rebuilt with considering both the beam scanning mode and the body shake. According to the rebuilt signal model, we derive the body shake error estimated method to compensate for the phase error. Simulation on the reconstruction of point targets with shake errors and proof-of-principle experiments on the human body in the 0.2-THz band are both performed to confirm the effectiveness of the body shake compensation algorithm proposed.     

Non-stationary electrical charging of a conductive body in the medium with the ionic component at instantaneous loss by a body an electrical link with earthed object

Theoretical and numerical research of electric charging of conducting body in the environment with ionic component at instant loss by a body of electric contact to the earthed object is carried out. Two situations are considered: the first, stationary situation which is realized when the electric current, coming on a body, through contact leaves on the earth. The second, non-stationary situation, arises when contact of a body to the earthed object disappears, and on a body the electric charge starts to grow. On the basis of electro-dynamic equations the general statement of a problem is given. Numerical modelling is executed.     

基于(火积)理论的“+”形高导热构形通道实验研究

基于构形理论和■理论,对"+"形高导热通道的方形构造体开展导热实验研究,并对不同优化目标和不同高导热通道布置形式下的构造体导热性能进行比较.结果表明:对于"+"形高导热通道的方形构造体,实验和数值计算所得到的构造体最高温度点均位于"+"形高导热通道两分支之间,实验和数值计算所得到的构造体平均温差和■耗散率的误差均在可接受范围内,这从定性和定量的角度证明了导热构形优化结果的正确性.与"H"形高导热通道的方形构造体相比,构造体内高导热通道采用一级"+"形布置使得其导热■耗散率得到降低.■耗散率最小的一级"+"形高导热通道构造体最优构形与最大温差最小的构造体最优构形相比,前者的导热■耗散率降低了5.98%,但最大温差提高了3.57%.最大温差最小目标有助于提高构造体的热安全性,■耗散率最小目标有助于提高构造体的整体导热性能.在保证热安全性能的前提下,实际微电子器件设计中可采用■耗散率最小的构造体最优构形以提高其整体导热性能.     

Quasi-Hamiltonian principle of liquid-filled elastic body dynamics

Liquid-filled elastic body dynamics is an important branch of fluid-solid coupling mechanics. It deals with the study of motion of a body and the liquid contained in the body under the interaction between the two,for example,a liquid-filled satellite,a fuel tank of an airplane,etc. The research on liquid-filled elastic body dynamics is usually done by the variational method since the method has a feature of treating things as a whole. Considering the elastic motion of the liquid-filled body and the surface tension effect on the liquid-gas interface,liquid-solid interface and gas-solid interface,the present paper establishes a quasi-Hamiltonian variational principle for the above-mentioned system. After finding the stationary-value conditions of its functional obtained,a complete system of governing equations consisting of the stationary value conditions,preconditions and constraint conditions is established,and then the equations are reduced into some known ones in a special case.     

富营养化水体环境中COD浓度遥感监测系统设计

对富营养化水体环境中COD浓度进行遥感监测,可以预防富营养化水体环境中COD浓度增加,提高水体水质,增加水循环次数,减少水体中有机物的污染。当前富营养化水体环境中COD浓度遥感监测系统设计方法,以Modis遥感影像数据为原理,依据富营养化水体环境中COD浓度的特征提取结果,对富营养化水体环境中COD浓度进行遥感监测,没有具体对遥感监测系统进行详细地设计,无法获取富营养化水体环境中COD浓度高精度的遥感监测信息,存在遥感监测结果偏差大的问题。提出了一种基于Zigbee的富营养化水体环境中COD浓度遥感监测系统设计方法。该方法先对Zigbee的富营养化水体环境中COD浓度遥感监测系统进行硬件设计,采用IMF对富营养化水体环境中COD浓度进行特征提取,以特征提取结果为基础,依据COD浓度指数时间序列实现富营养化水体环境中COD浓度遥感监测,最后利用Retinex法对COD浓度遥感监测的图像进行处理,完成对富营养化水体环境中COD浓度的遥感监测。仿真实验结果证明,所提系统设计方法可以精确地对富营养化水体环境中COD浓度进行安全快速的遥感监测。     

Mathematical modeling of rotation effects on conjugate heat and mass transfer at a high-enthalpy flow around a spherically blunted cone at incidence

Some methods of thermal regime control for three dimensional flows around a body due to the simultaneous impact of body rotation around the longitudinal axis, mass ablative surface, and heat transfer flow in the body shell material are considered. The solution to the dual formulation allows us to take into account the impact of nonisothermal shell wall on the characteristics of heat and mass transfer in the boundary layer. The effect of the body rotation and the injection of cooler gas on the characteristics of heat and mass exchange in a thermal protection material is analyzed.     

Effect of body biasing on single-event induced charge collection in deep N-well technology

As the device size decreases, the soft error induced by space ions is becoming a great concern for the reliability of integrated circuits(ICs). At present, the body biasing technique is widely used in highly scaled technologies. In the paper, using the three-dimensional technology computer-aided design(TCAD) simulation, we analyze the effect of the body biasing on the single-event charge collection in deep N-well technology. Our simulation results show that the body biasing mainly affects the behavior of the source, and the effect of body biasing on the charge collection for the n MOSFET and p MOSFET is quite different. For the n MOSFET, the RBB will increase the charge collection, while the FBB will reduce the charge collection. For the p MOSFET, the effect of RBB on the SET pulse width is small, while the FBB has an adverse effect. Moreover, the differenceof the effect of body biasing on the charge collection is compared in deep N-well and twin well.     

Near-Infrared Spectroscopy Probe with Position Sensor

We propose a probe for near-infrared spectroscopy that enables exploratory diagnosis and the simultaneous measurement of metabolic status and dynaMisc of the body of a subject. The probe has a red light emitting diode for indicating its position in addition to a set of two near-infrared light emitting diodes and a photodetector for near-infrared spectroscopy measurement. The red light is detected by a camera and the probe position is obtained by processing the captured images. There are two methods of using the probe: In one method, the user scans the probe on the body surface to obtain a spatial distribution of metabolic status; in the other method, the probe is fixed on the body and simultaneously measures metabolic status and movement of the body to investigate their relationship.     

Nonholonomic LL systems on central extensions and the hydrodynamic Chaplygin sleigh with circulation

We consider nonholonomic systems whose configuration space is the central extension of a Lie group and have left invariant kinetic energy and constraints. We study the structure of the associated Euler–Poincaré–Suslov equations and show that there is a one-to-one correspondence between invariant measures on the original group and on the extended group. Our results are applied to the hydrodynamic Chaplygin sleigh, that is, a planar rigid body that moves in a potential flow subject to a nonholonomic constraint modeling a fin or keel attached to the body, in the case where there is circulation around the body.     

Incremental approach to strongly correlated many-body finite systems

The transition and the Green operators of an interacting N body system are obtained from the solutions of the N-M body problem where M = 1,2,ellipsis,N-2. This is achieved via the development of a cumulative, nonperturbative approach that makes use of existing knowledge on the system when the number of interacting particles is reduced. The method is applied to four interacting Coulomb particles where the Green operator is expressed as a sum of Green operators of all three body subsystems that can be combined within the four body system. The calculated four particle continuum spectrum is in a remarkable agreement with recent experimental findings.     

Gas damping force noise on a macroscopic test body in an infinite gas reservoir

We analyze here the force noise associated with the mechanical damping of a test body surrounded by a large volume of rarefied gas, considering the statistics of momentum exchange in inelastic molecular collisions. In addition to calculating the force noise on a cube, sphere, and cylinder, we discuss the limits in applying this analysis to experimental configurations in which the test body is surrounded by an enclosure that is only slightly larger than the test body itself.     

Hydroelastic dynamic characteristics of a slender axis-symmetric body

The slender axis-symmetric submarine body moving in the vertical plane is the object of our investigation.A coupling model is developed where displacements of a solid body as a Euler beam(consisting of rigid motions and elastic deformations) and fluid pressures are employed as basic independent variables,including the interaction between hydrodynamic forces and structure dynamic forces.Firstly the hydrodynamic forces,depending on and conversely influencing body motions,are taken into account as the governing equations.The expressions of fluid pressure are derived based on the potential theory.The characteristics of fluid pressure,including its components,distribution and effect on structure dynamics,are analyzed.Then the coupling model is solved numerically by means of a finite element method(FEM).This avoids the complicacy,combining CFD(fluid) and FEM(structure),of direct numerical simulation,and allows the body with a non-strict ideal shape so as to be more suitable for practical engineering.An illustrative example is given in which the hydroelastic dynamic characteristics,natural frequencies and modes of a submarine body are analyzed and compared with experimental results.Satisfactory agreement is observed and the model presented in this paper is shown to be valid.     

Supersonic flows with small perturbations in the presence of external effects in the flow. Part 1: “Thin body of revolution”

Axisymmetric supersonic flow about a thin body of revolution with an external energy supply and an external force localized near the body surface is considered in the linear approximation. An analytic theory is constructed for calculating spatial fields of flow parameters in this case for an arbitrary dependence of external effects on the longitudinal coordinate. Formulas are derived for the pressure ratio on the surface of the thin body of revolution. The results of calculations based on the analytic theory are in good agreement with numerical data obtained from the solution of hydrodynamic equations in the Euler approximation.     

A novel iterative direct-forcing immersed boundary method and its finite volume applications

We present a novel iterative immersed boundary (IB) method in which the body force updating is incorporated into the pressure iterations. Because the body force and pressure are solved simultaneously, the boundary condition on the immersed boundary can be fully verified. The computational costs of this iterative IB method is comparable to those of conventional IB methods. We also introduce an improved body force distribution function which transfers the body force in the discrete volume of IB points to surrounding Cartesian grids totally. To alleviate the demanding computational requirements of a full-resolved direct numerical simulation, a wall-layer model is presented. The accuracy and capability of the present method is verified by a variety of two- and three-dimensional numerical simulations, ranging from laminar flow past a cylinder and a sphere to turbulent flow around a cylinder. The improvement of the iterative IB method is fully demonstrated and the influences of different body force distribution strategies is discussed.     

基于Android手机的健康调理手环设计

针对人体日常行为习惯做出健康调理建议,设计了基于Android智能手机的健康调理手环系统,采用包含人体测量手环和Android智能手机应用软件的系统结构;对人体测量手环的蓝牙模块、加速度传感器、心率传感器、体表温度传感器等硬件电路和软件流程算法进行设计,重点研究并提出了人体卡路里数综合消耗估计方法,并对Android操作系统的应用软件健康调理建议APP进行设计与实现。实验结果显示,系统能够有效实时测量人体数据,估算人体卡路里消耗,给出人体健康调理食谱和饮食建议,实现设计效果。