Showing papers by "Zhejiang University published in 1985"
TL;DR: In this article, a self-lubricated porous metal bearing with a special non-uniform distribution of permeability is introduced, which has been manufactured using a practical production process, its local permeability varying regularly along its circumference.
18 citations
TL;DR: In this paper, an experimental study has been made of sintered bronze bearings under high speed and light load conditions, and the results indicated that the correct selection of oil for porous bearings is very important.
13 citations
TL;DR: In this paper, the first study of a new kind of Ziegler-Natta catalyst, the combination of a scandium compound and aluminum trialkyl, for the polymerization of acetylene was reported.
9 citations
TL;DR: In this paper, the lifetime of a CuBr laser with flowing neon as a buffer gas was extended to 734 h by considering the flow of the buffer gas and combined structure of the discharge tube.
7 citations
TL;DR: The rare earth coordination catalysts are cis-directing catalysts for the polymerization of acetylene and a kinetic study was carried out to get more insight into the features of these catalysts as mentioned in this paper.
7 citations
TL;DR: In this paper, high cis polyacetylene films with silvery metallic appearance were prepared by coordination catalysts, comprising of naphthenates of all fifteen rare earth elements, and trialkyl aluminum at room temperature.
7 citations
TL;DR: In this paper, the PICKER flow microcalorimeter operated in discontinuous mode was used to measure the entropy of carbon tetrachloride with ethanol, i-propanol, n-butanol and 2-octanol.
6 citations
TL;DR: In this article, the aSi:H films were deposited through glow discharge decomposition of monosilane-hydrogen gas mixtures and the change of concentration of the SiH and SiH 2 groups in the film with the substrate temperature and rf power, the deposition rate, and the thermal evolution of the hydrogen were determined.
Abstract: The aSi:H films were deposited through glow discharge decomposition of monosilane-hydrogen gas mixtures. The change of concentration of the SiH and SiH 2 groups in the film with the substrate temperature and rf power, the deposition rate, and the thermal evolution of the hydrogen were determined. They show that the deposition behavior differs with the variation of these parameters. In spite of the complexity of plasma and surface reactions, it is implied that three main surface reactions play an important role in the deposition: the chemisorption of the Si and SiH free radicals, the plasmaasisted hydrogenation, and the plasma-assisted dehydrogenation. Based on these reactions, a general expression of the deposition rate is given. It yields the calculated results in good agreement with the experimental data on the deposition rate.
6 citations
TL;DR: In this paper, the authors describe the application of optimal control theory to a practical example of minimum energy consumption in steel rolling, where heavy reversing rollers are continually starting and braking.
Abstract: This paper describes the application of optimal control theory to a practical example, that of minimum energy consumption in steel rolling. In a steel plant, heavy reversing rollers are continually starting and braking. The driving motor operates mainly in the dynamic state thus consuming a large amount of energy. This paper analyzes the process of dynamic energy consumption, and further, applies the optimal control theory to minimize this. Both theoretical analysis and experimental results are encouraging.
5 citations
TL;DR: Based on the discrete state space model of the ingot-pit systems and the novel algorithm for solving the constrained optimal control problems developed by the authors, the optimal heating patterns are developed theoretically for minimizing the fuel consumption in the soaking pits as mentioned in this paper.
5 citations
TL;DR: In this paper, the effect of turbulence is considered by a coupled item of interaction force between solid particles and gaseous species, and the equations are solved through the modified SIMPLE method.
Abstract: The numerical study of the pneumatic transport in a two-phase turbulent horizontal flow at high loading, q> 10, has been developed. The effect of turbulence is considered by a coupled item of interaction force between solid particles and gaseous species. The equations are solved through the modified SIMPLE method. The steady solution has been carried out by using the time-dependent method. As a special example, pneumatic transport of a mixture of a gas and a solid in hollow cylinders of polyethylene in a turbulent horizontal flow is solved. (Diameter of the pipe, D: 55 m Length, L: 36.73 m, d: 3 to 4 mm, P S: 958 kg/m3 ). The results show excellent agreement between the numerical calculation and the experiment. Some problems for pneumatic transport at high solids loading have been discussed. The present method is also applicable to pneumatic conveyance in telescoping pipes.
TL;DR: In this article, a conformal mapping of the rectaugle region in which the cracks emerge into upper-half part of the ζ plane was proposed, and the stress intensity factors were derived.
Abstract: Originating from Robert Hooke's law and equilibrious equations, and using the theory of the complex variable function, this paper transfers the rectaugle region in which the cracks emerge into upper-half part of ζ plane by means of conformal mapping. Then according to the theory of ref. [1]. We find the solution in closed form, thereby the stress intensity factors are derived.
TL;DR: Advances in the design of special cryobiomedical apparatus and a review of the trend of developments in the field of cryosurgery in China are discussed and the development of commercial cryosurgical apparatus in China is discussed.
TL;DR: In this article, Euler-Lagrange type equations are used to describe the jet flow of a mixture of pulverized coal and gas, which is an unsteady axisymmetric two-phase flow.
Abstract: In this paper, Euler-Lagrange type equations are used to describe the jet flow of a mixture of pulverized-coal and gas, which is an unsteady axisymmetric two-phase flow. By means of the finite-difference method, the coal particle's distribution, velocity and trajectory in the flow field are obtained. The coal particles are represented by a finite number of computational particles. Each particle's diameter is randomly assigned according to a given distribution. The states of the computational particles are different from each other. Turbulence is accounted for in a stochastic model. Explicit time-splitting scheme is used to calculate the strongly coupling interphase term. The numerical results are reasonable. The comparison between the numerical results and the experiment data for the case of the oil droplet injection shows good agreement. This numerical technique can be extended to the calculation of other two-phase flows of dilute particles or a droplet system.
TL;DR: A synthetic high coding combined with DPCM coding for the luminance signal to meet the requirement for the transmission of PAL TV signals and the quality of the coded picture is similar to an 8 bit/pel PCM picture by subjective test.
TL;DR: In this paper, a dynamic model of a saper machine is built by the mechanismic analysis and some mathematical treatments, and a new frequency response approach to multivariable control system design is developped by optimization technique and applied to the design of a basis weight and moisture content control system.
01 Jan 1985
01 Jan 1985
TL;DR: In this article, the self-consistent Hartree-Fock-Slater molecular cluster calculations for the chemisorption of carbon monoxide on a Rh(110) surface both at on-top and at on fourfold "pocket" sites are presented.
TL;DR: In this paper, the authors introduced the shooting method for two-point boundary value problems of ordinary differential equations with parameters, and gave an example of solving hydrodynamic lubrication equation by using shooting method.
Abstract: In this paper. first we introduce the shooting method (including the method of adjoints and the method of quasilinearization) for two-point boundary value problems of ordinary differential equations with parameters, and give out an example of solving hydrodynamic lubrication equation by using the shooting method. The calculated results are satisfactory.
TL;DR: In this paper, a finite element method using triangulated elements, six points quadratic interpolation for improvement is presented to calculate not only the fundamental and longitudical modes but also the transverse higher modes of RF cavity.
Abstract: A previous paper has presented to calculate not only the fundamental and longitudical modes but also the transverse higher modes of RF cavity. But with this method higher modes are calculated one by one. In this paper we present a finite element method using triangulated elements, six points quadratic interpolation for improvement. At first, we obtain a tridiagonal coefficient matrix with the Householder method, then calculate its eigenvalues using half-divided method. With this method we can calculate any order eigenvalues(and resonant frequency values) and the responding eigenvectors (and field distribution) of a mode group simultaneously at one time. This method is convenient, accurate and economical for computing time.
01 Jan 1985
TL;DR: In this paper, a modified quantum model of spin glasses, in which the self-interaction was included, and considering the perfect disorder state, was presented, and it was proved that the spin glasses system is equivalent with a three-dimensional oscillator system including non-linear coupling.
Abstract: Presenting a modified quantum model of spin glasses, in which the self-interaction was included, and considering the perfect disorder state, we have proved that the spin glasses system is equivalent with a three-dimensional oscillator system including non-linear coupling. Neglecting some parts of non-linear coupling terms, we obtained the exact solution on energy partition function for spin glasses system. On this basis, calculating the entropy, free energy, specific heat and susceptibility, we obtained the spin glasses characteristics well.
TL;DR: In this article, the β-functions of SU(2) lattice gauge theories with SIN and EXP actions are investigated by means of Monte Carlo renormalization group method (MCRG).
Abstract: The β-functions of the SU(2) lattice gauge theories with SIN and EXP actions are investigated by means of Monte Carlo renormalization group method (MCRG). Only one ultraviolet fixed point is observed. The finite size effect and the connection with the continuum limit are discussed.
TL;DR: In this paper, the authors present an application of discrete parameter adaptive control to the temperature tracking control system of steel mill soaking pits, the dynamic behaviors of which are heavily dependent upon the operating conditions, such as the number, size and initial thermal state of the ingots charged in the pit.
01 Jan 1985
TL;DR: In this article, the response of elastic structure to random earthquake excitation is analyzed for a frame-wall system, practical calculating formulas are derived and a program in FORTRAN language is made.
Abstract: In this paper the response of elastic structure to random earth-quake excitation is analysed. For a frame-wall system, practical calculating formulas are derived and a program in FORTRAN language is made. The program is checked with a numerical example. The envelope of the lateral displacement of the system and the variation regularity of the internal forces are determined from given values of dynamic reliability (first excursion probability) based on the requirement of the operation of the structures.