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1.
本文对稻种的气调包装,真空包装,充纯氮包装,普通含空气包装等多种包装储藏形态与未包装的散装储藏进行了对比试验。并采用正交试验设计方法,对影响稻种包装储藏发芽率的稻种含水率,塑料薄膜性能,气体条件等因子作了方差分析。实验表明,稻种含水率愈高发芽率愈低,采用阻湿性较好,阻气性差,价格低廉的薄膜,有利于抑制稻种的呼吸作用,又能维持稻种的生命力,对提高发芽率有利。  相似文献   

2.
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.  相似文献   

3.
The paper presents a Monte-carlo method for reliability evaluation of large scale composite generation transmission systems. The method, which possesses coputational rapidity and sufficient accuracy,is based on combining the dispersed sampling techique with the analysis approach and the optimization model of power not supplied. Because the amount of calculation increases only linearly with, the number of elements, it is specially sui- table for large scale systems. The Monte-carlo sampling draws more near the real situation than determinate state enumeration in simulating occurrence of power system outages. Also, the method can be easily generalized to involve multi-states of elements, multi-levels and stochastic distribution of loads. The results of IEEE-RTS, as example, are given and compared with ones obtained by using the other two methods.  相似文献   

4.
A Monte Carlo approach is appplied to the error estimation and error analysis of X-ray diffraction standardless quantitative phase analysis and the coefficient of its variation is cal dilated .which is compared with the error estimation by the condition number of the coefficient matrix of linear equations. The Monte Carlo error estimation is applied to the standardless quantitative matrix-flushing method, in which the mixture of KC1. CaCO3. ZnO and BaCO3 is analyzed as an example.  相似文献   

5.
The secant rigidity is used for the are-length method to solve the nonlinear finite elements problems. The advantage of this method is unnecessary of calculating the initial resistance term caused by the incremental step. The computational work is less and the programing is easier as compared with initial are-length method. This method can be widely used to solve nonlinear problems.  相似文献   

6.
By means of the method of integral equation of ring shells ininitial parameter form,the problems of S-type corrugated tubes are studied inthis paper.Two calculating examples are given,and compared with the exactsolutions.  相似文献   

7.
The rigid-viscoplastic finite element formulations for the analysis of non-stationary deformation in the edge rolling is established on the basis of the simplified 3-D. element. A new method for obtaining inital velocity field is developed in this paper. It has been used successfully to analyse the non-stationary deformation in the edge rolling of lead plates. The calculated results are found to be in good agreement with those obtained from expriements.  相似文献   

8.
It's a historical inexorable trend that the development of architecture is synchronistic with the social economic and science and technology.Dwelling also faces new transformation with the passage of times.This paper makes a systematic analysis in theory,method and conception.It includes four parts,they arc cataclysm of living requirement,al-ter of general conception,the renewal of composition method,and the exploration of new style.  相似文献   

9.
The producing mechanism and developing law of the temperature restraint stresses on the layer-face of photoelastic model with variable elastic modulus are investigated with experimental studies and theoretical analysis, and the stability of the fringe figure of the restraint stresses or the fixedness of the restraint is verified repeatedly with the experiment. Thus the single model method of eliminating the influence is put forward, and the formula with superposing of fringe parameters of the method is given. The single model method is of great importance to eliminat the influence of the restraint stresses on photoelastic modelling with variable elastic modulus for soil and rock engineering and improving the experiment accurcy.  相似文献   

10.
A two-story and two-space structure model (1/4 scale) is tested under low-cyclic loading for studying the antiseismic behavior of the brick building with frame on the ground floor. This paper presents mainly the development and pattern of cracks, failure mechanism,hysteresis behavior, strength and stiffness, ductility and energy dissipation. The calculated results by elastic finite elemet method are also compared with the results of test.  相似文献   

11.
小麦品种对赤霉病抗扩展类型抗性组分的探索分析   总被引:5,自引:0,他引:5  
余毓君  廖玉才 《作物学报》1988,14(3):194-201
本文探索了一种较客观地反映小麦品种对赤霉病抗扩展性的方法——抗性组分分析法。对13个品种双列杂交的后代,按 Griffing 方法Ⅱ模式Ⅰ研究了6个抗性组分的配合力。结果表明:供试品种各抗性组分真实存在,不同抗病品种阻止病菌扩展的方式不同;主穗轴发病和田间接种后15及25天的病级这三个组分可作为衡量品种抗扩展性的主要指  相似文献   

12.
This paper briefly introduces Patankar-Spalding Method, which is systematical, active and widely applicable in numerical heat transfer and fluid flow. The corresponding dependent variables, diffusivities and source terms for the general differential equations under all circumstances are explained. By using this method the calculation of two-dimentional Poiseuiue Flow and Couette Flow compared with exact solutions are proved to be high precision. with two-dimentional path-flow in the heat convertor intersification devices as an example, the tilted method is used with FORTRAN 77 programming, and the calculation is done on a SIEMENS 7570c minicomputer.  相似文献   

13.
The modality analysis method is employed in this paper to study the influence of mass distribution on dynamic characteristics of a spindle system. It is found that there exist obvious difference between the influences of different mass distribution on the natural frequencies . and modality flexbilities of various order-mode. It is shown that the proportion of modality flexbility in the astatic flexbility can be equilibrated by means of adjusting correctly the mass distribution of the spindle system so that the cutting stability is improved as well. Experiment results are quoted to confirm, in a certain degree, the conclusion above.  相似文献   

14.
A processing method for the weight of the object in the fuzzy solving method for the multiojectide optimization are presented. The methods are using different type of membership functions and using the same kind membership function adjusting the parameter. Some corresponding analysis and examples are discussed and the results show that the two methods are very effective.  相似文献   

15.
The paper provides a detailed study of switching conditions of minimum-time control systems based on application in engineering. By analysis in theory and experiment, the authors deduce a set of switching conditions with state and control variabes inequality constraints, the variations of system parameters and the time-delay of computer in real time control. As an example, a DC motor speed control system is considered. By digital simulation and physical experiments,these conditions proved to be correct. The method in this paper is also suitable for other control systems using compound control algorithm.  相似文献   

16.
A method for coupled analysing plastic deformation of rolling workpiece and elastic de'formaticn of rolls is developed. The interaction of plastic defo rmation of rolling workpice and elastic deformation of rolls is considered. The couple is formulated by setting up force equilibrium equation at the interface of the rolling workpiece and tne rolls. The plastic deformation of rolling workpiece is treated by the rigid plastic finite element method and the elastic deformation of rolls is treated by the boundary element method. The rolling presure, perunit. forward slip, neutral from angle obtained from coupled analysis are lower than those obta-ined rigid rolls. The results obtained from analysis show that the analytical accuracy can be heightened using the coupled ana-ytical methcd dveeloped for treatng rolling3proccss.  相似文献   

17.
This paper presents some ideas of graph theory which are led int(?) structural matrix analysis. The main contents of this paper are the principal points of the graph theory, the computative principles of the node method and the mesh method.  相似文献   

18.
A modelling design approach for the preliminary dimensioningof underground opening supports is presented in this paper. The method is basedon the model test results under the condition of plane deformation, It is tobe used for the analysis and design of the primary support measures and theproper thickness of secondar linings as welt as appropriate construelion tech-niques adapted to the condition of the Caiyuan Tunnel in Chongqing.  相似文献   

19.
稻谷脂肪酸值测定条件优化与比较的研究   总被引:1,自引:1,他引:0  
研究了提取时问、振荡速率、过滤分离与离心分离等对稻谷脂肪酸测定结果的影响.并对人工滴定法和仪器法测定脂肪酸值进行了比较.结果表明:提取时间对脂肪酸提取率的影响较小,提取时间10 min即可较完全提取样品脂肪酸;随着振荡速率增加,脂肪酸提取率提高,当振荡速率达到125 r/min以上时,样品中的脂肪酸基本提取完全;手工过滤和离心分离制备提取液,测定结果无显著性差异;仪器法测定结果的精密度高于手工滴定法.  相似文献   

20.
The computation principle for the pipe-casing gun of the equal acress-section area is studied by applying the basic theory of compressible. The aerodynamic parameter of the pipecasing gun and the friction factor of rustless sted-pipes and copper-pipes of different diameters are measured. On the basis of this measurement, the outlet-velcity profile and the change of the rate and pressure on the axis are measured. The results show that the friction factor measured is reliable and the computation method is practical.  相似文献   

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