THE APPLICATION OF MULTIBODY DISCRETE METHOD IN RING''S VIBRATION ANALYSIS

A ring's muJtibody discrete model is discussed in this paper. The ring's plane geometric nonlinear vibration equations are derived. Compared with the finite element and lump mass methods, this method is better. In the last pa it of the paper, the eigenvalues, the first 9 modes of the ring, the geometric nonlinear dynamic responses of the ring are calculated.     

THE METHOD OF IMPROVING THE SPEED AND ACCURACY OF FFT AND SPECTRUM ANALYSIS

FFT(Fast Fourier Transform)is the basis of spectrum analysis. This paper gives out a method which can improve the speed and accuracy of FFT. The spectrum analysis based on the proposed method is of a high level: the amplitude error of spectrum is less then 1 % , the time of completing 1024 compler points FFT and 32 segments spectrum analysis is less then 250ms and only 5 seconds respectively.     

COUPLING ANALYSIS METHOD FOR INTERACTION BETWEEN FOUNDATION WITH CAVERN AND FRAME STRUCTURE

In this paper,the interaction between foundation withcavern and frame structure is studied by the coupling methods of BEMand FEM.On the interface between the foundation and structure,thecoupling analysis needs to satisfy both the condition of displacementcompatibility and force equilibrum.A calculating program for two-dim-ensional problem is worked out in the computer,SIEMENS 7570C.Twoengineering examples are calculated and the results are compared withthose obtained by the comventional simplified method and with the observedresults from the engieering structures.It indicates that it is necessaryfor the weak rock foundation with shallow cavern,in the buried depth,to take the interaction into account.     

DYNAMIC ANALYSIS AND NUMERICAL METHOD FOR THE HYDRAULIC SYSTEM IN A TUBE AND FORM-BAR PRESS MACHINE

In this paper, dynamic analyses are made for (he pump and energy-store hydrauic system in a 3150 ton tube and form-bur press machine. The formulas for calculation are derived, and the so are the relationship between the press and the displacement, and the velocity and the acceleration. Numerical calculations are also made. The calculated results coincide with the measured data. The method in this paper has a universal reference meaning for all types of press machines with the type pump and energy-store hydraulic system.     

DYNAMIC ANALYSIS AND NUMERICAL METHOD IN PHE DRIVE MECHANISMS OF THE STEEL-TUBE COLD-ROLLING MACHINE

In this paper, the calculating formulas for partial dynamic balance of crankslider mechanisms are derived in terms of the limear independent vector theory. The driving torque and the optimum selections for partial dynamic balance in drive mechanism of the steeltube cold-rolling machine are carried out. The method in this paper has a universal reference meaning for the partial dynamic balances of crankslider mechanisms.     

THE THEORETICAL ANALYSIS OF RADIAL DISPLACEMENT AND COMPATIBLE CONDITIONS OF BOTTOM PLATE OF PISTON FRAME IN LARGE CONTAINER

Taking aecount of shear action between the piston truss the bottom plate, this paper assumes the bottom plate to be a part-ring and supposes that the shear distribution follows the power series law, making the problem to be a problem of mixed boundary condition of part plate. In the paper, the solution of this elastic plane problem is derived. The general expressions of radial displacement of bottom plate are given. The compatible conditions both at the nodes of the lower chord of the truss and at the central cylindrical shell are analyzed.     

ANALYSIS OF THE TIME HISTORY RESPONSE FOR LARGE STRUCTURE UNDER THE ACTION OF IMPULSIVE LOADING USING STEP-BY-STEP REDUCED DYNAMIC-STIFFNESS COMPOSITION METHOD

In this paper, a dynamic substructure method for analysing the transient response of the large structure is proposed. The method is based or, the combination of the reduced dynamic-stiffness composition method and the step-by-stop integration method. Its main feature is that the computational effort may be reduced significantly. Several examples are given to prove its reliability, effectiveness and accuracy.     

CALCULATION OF GENERALIZED INTEGRALS USING DIFFERENTIAL OPERATOR SERIES METHOD

This paper introduced computational basis and examples of generalized integrals using differential operator series method.     

ON THE UTILITY SUM OF ACCUMULATED PRESENT VALUE FOR THE ECONOMIC EVALUATION OF INVESTMENT PROJECT

To counteract the weakness of Net Present Value, a new index, the utility sum of accumulated net-cash-flow present value, is put forward in this paper.     

凯氏定氮法测定大米中蛋白质的不确定度分析

采用GB/T5009.5-2003第一法,凯氏定氮法测定大米中蛋白质的含量,其测量不确定度来源于样品称量、消化、定容、移取消化液、蒸馏及滴定等过程。通过对各个不确定度分量的计算合成,找出影响测量不确定度的因素,并对各个不确定度分量进行评估,最终分析出样品大米中蛋白质的标准不确定度及扩展不确定度并描述了影响大米蛋白质测定结果各分量对其不确定度的相对贡献。     

AREA-VECTOR METHOD CALCULATJJNG THE DISPLACEMENTS OF BEAMS AND FRAMES

A new method with which to calculat the displacements of beams and frames is presented. The areas of tending moment diagram of beam or frame and the slope at the origin of the elastic curve are treated as some rotatable vectors with this method. Angular displacement and in-line displacement can be calculated by using the projection and moment of these vectors. This method can be used to calculate displacement of the bar and the bar syttem ( including three dimensional forms. ) , which made from linear or ncnlinear elastic materials. The cross section of the bar is changeable.     

谷物不溶性膳食纤维测定方法研究

修改采用AACC32-20(1999)<不溶性膳食纤维测定方法>,对原国家标准GB/T9822-1988<谷物不溶性膳食纤维测定方法>进行了研究和讨论分析.结果表明,纤维测定仪器可以作为谷物不溶性膳食纤维的测定仪器,样品的粉碎粒度为20-30目,α-淀粉酶浓度为2.5%(W/V),取消了试剂中的十氢萘,样品不溶性膳食纤维测定值的相对误差小于10%.     

AN EFFECTIVE DESIGN METHOD FOR PREVENTING COL LAPSE OF MULTI-STORY BUILDINGS TAKING ACCOUNT OF STRUCTURAL LOW-CYCLE FATIGUE CHARACTER

In this paper, through the theoretical analysis and a number of calclating, the statistic regression about the parameters in the failure criteria for aseismic structures presented by the authors are made. Based on this work, a simplified method for preventing collapse of multistory buildings taking account of structural low-cycle fatigue character is proposed.     

THE ANALYSIS OF MECHANICAL CONSTRUCTION OF SURROUNDING ROCKS IN THE PITCHING SEAM

Defferent forms of mechanical construction, the distribution of stress, and the process of the deformation destruction in the enclosing rocks in a working face of a pitching seam are analyzed according to its geological and mining specialities.     

ANALYSIS FOR VIBRATION OF ARCHES BY TRANSFER MATRIX METHOD

This paper presents a transfer matrix method for analysing dynamiccharacteristics of arches.The calculation models are the broken-line rigidframes with a series of mass points,which are simplified from the criginalstructures.The geometric stiffness and the axial deformation of arch are consi-dered in formulating its vibration transfer equation.Through application ofthe method,the vibration modes and the relative values of internal forces canbe obtained simultaneously as soon as the vibration frequencies of arch areknown.The simple and direct method developed may be easily calculated withmicrocomputer,and it has extensive usage with high precision.     

PAYING ATTENTION TO USE SIMPLEX METHOD FOR OPTIMAL MULTIPARAMETER IN THE DESIGN OF CONTROL SYSTEM

In the design of control system using simplex method for optimal multi-parameter,if the difference in number between the greatest and the smallestparameters is very great,the optimization process converges very slowly.Evenoptimal parameters can't be found at all.This paper studies the problem,analyses its cause and poses a resolution means.A testing example shows thatthis means can solve the above problem well.     

水稻籽粒灌浆的生长分析

用 Richards 方程 W=A/(1+Be~(-kt))1/N 配合农垦57号、汕优63号等6个品种(含杂种)强、弱势粒的籽粒增重资料。依弱势粒配得方程的 N 值,将此6个水稻品种的籽粒灌浆状况分为两个类型,即:01的异步灌浆型。并据籽粒生长速率曲线的两个拐点,将籽粒灌浆过程划分为:前,中(盛)、后(至90%A 止)3个期。同时导出:起始生长势 Ro=K/N,生     

ORTHOGONAL COLLOCATION METHOD AND IT APPLICAIONS IN THE CALCULATION OF DYNAMIC CHARACTERISTICS OF HEAT EXCHANGER

Being a kind of MWR, the orthogonal colloacation method can be conveniently used to reduce the initial-boundary value problems of the partial differential equations to initial value problems of ordinary differential equations. In this paper, the orthogonal collocation method is introduced in detail and by using it the dynamic characteristics of a steam-water heater are investigated.