Calculation of Taper Rolling Time in Plan View Pattern Control Process

The forward slip model with adhesion was used to derive the formula of calculating taper rolling time. The relation between the rolling time and the taper length and the relation between the rolling time and the taper thickness can be obtained. The numerical solution for this formula was used on site. According to the simulation result, the roll gap value should be changed linearly with rolling time.

Calculation of left ventricular diastolic time constant(Tau) in dogs with aortic regurgitation using continuous-wave Doppler spectra

OBJECTIVE To investigate a new noninvasive method for calculating left ventricular diastolic time constant(Tau) through a continuous-wave aortic regurgitation Doppler spectrum.METHODS According to ultrasound guidance, twenty-four animal models(beagles) of aortic regurgitation and acute ischemic left ventricular diastolic dysfunction were created. The left ventricular diastolic function was manipulated with dobutamine or esmolol and fifty-nine hemodynamic stages were achieved. Raw audio signals of the continuous-wave Doppler spectra were collected, and new aortic regurgitation Doppler spectra were built after reprocessing by a personal computer. The updating time of the spectral line was 0.3 ms. The new Doppler spectra contour line was automated using MATLAB(MATrix LABoratory, MathWorks, Natick, MA, USA), and two time intervals,(t2–t1) and(t3–t1) were measured on the ascending branch of the aortic regurgitation Doppler spectrum. Then, the two time intervals were substituted into Bai's equations, and Doppler-derived Tau(Tau-D)was resolved and compared with catheter-derived Tau(Tau-c).RESULTS There is no significant difference between Tau-D and Tau-c(45.95 ± 16.90 ms and 46.81 ± 17.31 ms, respectively;P >0.05). Correlation analysis between Tau-c and Tau-D suggested a strong positive relationship(r = 0.97, P = 0.000). A Bland-Altman plot of Tau-c and Tau-D revealed fair agreement.CONCLUSIONS This new calculation method is simple, convenient, and shows a strong positive relationship and fair agreement with the catheter method.

Flexible Fixture Design for the Top and End Surface Processing of NP2_NP4 Cylinder Heads

This paper focuses on the design of fixtures for NP2 and NP4 cylinder heads on a horizontal machining center of flexible machining automatic lines.It began with an analysis of the diagrams of part processing and working procedure which formed the basis for the design of the processing technology scheme,a selection of suitable machine tools,and the setting of processing parameters.Fixtures tailored to the chosen machine tools were then designed to meet the processing requirements.Additional aspects of the project included the design of part drawings,calculation of working time quota,design of auxiliary guides,support clamping,and hydraulic circuits,all aimed at fulfilling practical production requirements.

Relativistic Reduction of the Electron-Nucleus Force in Bohr’s Hydrogen Atom and the Time of Electron Transition between the Neighbouring Quantum Energy Levels

The aim of the paper is to get an insight into the time interval of electron emission done between two neighbouring energy levels of the hydrogen atom. To this purpose, in the first step, the formulae of the special relativity are applied to demonstrate the conditions which can annihilate the electrostatic force acting between the nucleus and electron in the atom. This result is obtained when a suitable electron speed entering the Lorentz transformation is combined with the strength of the magnetic field acting normally to the electron orbit in the atom. In the next step, the Maxwell equation characterizing the electromotive force is applied to calculate the time interval connected with the change of the magnetic field necessary to produce the force. It is shown that the time interval obtained from the Maxwell equation, multiplied by the energy change of two neighbouring energy levels considered in the atom, does satisfy the Joule-Lenz formula associated with the quantum electron energy emission rate between the levels.

Circular Scale of Time as a Guide for the Schrodinger Perturbation Process of a Quantum-Mechanical System

We point out that a suitable scale of time for the Schrödinger perturbation process is a closed line having rather a circular and not a conventional straight-linear character. A circular nature of the scale concerns especially the time associated with a particular order N of the perturbation energy which provides us with a full number of the perturbation terms predicted by Huby and Tong. On the other hand, a change of the order N—connected with an increased number of the special time points considered on the scale—requires a progressive character of time. A classification of the perturbation terms is done with the aid of the time-point contractions present on a scale characteristic for each N. This selection of terms can be simplified by a partition procedure of the integer numbers representing N-1. The detailed calculations are performed for the perturbation energy of orders N=7 and N=8 .

Simulation and comparison of several numerical algorithms for solving ballistic differential equations

Several numerical methods of differential equations and their applications in ballistic calculation are discussed for the purpose of simplification of the dynamic differential equations of projectile trajectory.Program simulations of Euler method,Heun method,lassic fourth-order Runge Kutta（RK4）method,ABM method and Hamming method are achieved based on Matlab.In addtion,the approximate solutions,local truncation errors and calculation time of the dynamic differential equations are obtained.By analyzing the simultaion results,the advantages and disadvantages of these methods are compared,which provides a basis for choice of ballistic calculation methods.

A new method of aperture synthetizing in digital holography

This paper proposes a new method of aperture synthetizing in digital holography based on the principle of holography.In the new method aperture synthetizing is achieved by reconstructing each sub-hologram respectively,firstly,moving each reconstructed wave field referred to the benchmark reconstructed wave field according to the relationship between spacial motion and frequency shift,and finally splicing them by using superposition. Two different recording ways,using plane wave to record and using spherical wave to record,are analyzed,and their moving formula is deduced,too.Simulation and experiment are done. The results show that in comparison with the traditional method of aperture synthetizing in digital holography,the new method can decrease calculation and save reconstructed time obviously which has better applicability.

An improvement to the simulation of phase-change heat-transfer during soil freezing and thawing

A new variable time step method,which is called the backwards calculating time step method,is presented in this paper.It allows numerical simulation of soil freezing and thawing while avoiding "phase change missing and overflowing".A sensitive heat capacity model is introduced through which the calculation errors are analyzed.Then the equation using the self-adjusted time step is presented and solved using finite differences.Through this equation,the time needed for a space cell to reach the phase change point temperature is calculated.Using this time allows the time step to be adjusted so that errors caused by "phase change missing and overflowing" are successfully eliminated.Above all,the obvious features of this method are an accelerated rate for adjusting the time step and simplifing the computations.An actual example proves that this method can accurately calculate the temperature fields during soil freezing and thawing.It is an improvement over traditional methods and can be widely used on complicated multi-dimensional phase change problems.

Method for extracting angle-domain common image gathers in Kirchhoff beam migration

Kirchhoff beam migration is a simplified Gaussian beam migration,which omits the dynamic information and can calculate multi-arrival traveltime,so it is a high-precision and fast seismic imaging method.In the imaging process,extracting common image gathers can be used for velocity analysis,improving the accuracy of modeling and imaging quality.Compared with the conventional common image gathers extracting methods,the angle-domain common image gathers extracting method can avoid the artifacts caused by multi-arrival seismic waves.The authors present a new method of extracting common image gathers in angle-domain from Kirchhoff beam migration and verify the method by numerical calculations.