共查询到20条相似文献，搜索用时 31 毫秒
1.
As the BEM was used in the knaggy domain,its approach error was big.Domain Decomposition Method change the problem in the knaggy domain to the problem in several convex domains which do not wrap.The whole solution is gained by alternating boundary conditions between Dirichlet condition and Neumann condition on the common boundary.Domain Decomposition Method for Stokes equations in the anomalistic knaggy domain is presented,the example of Domain Decomposition Method in the flow of the lake in GuiYang City is given. 相似文献
2.
A theoretical analysis is presented for the snap-buckling behavior of thin shallow conical shells under axisymmetric line loads. By making use of the integral equation method and the modified iteration method, the second approximate formulas of elastic behavior are given. The effects of geometrical parameters and boundary conditions on the snap-buckling behavior are discussed 相似文献
3.
An extensive analysis on the existing results for the stability of Takagi Sugeno fuzzy control is given. For the Lyapunov functions, the common quadratic Lyapunov functions, piecewise quadratic Lyapunov functions, fuzzy Lyapunov functions, nonquadratic Lyapunov functions and homogenously polynomially parameterized Lyapunov functions are considered. For the control laws, the parallel distributed compensation laws, non parallel distributed compensation laws and homogenously polynomially parameterized control laws are considered. Based on the analysis, by applying the Polya's theorem and the techniques for homogenous polynomials, the approaches for approximating the necessary and sufficient conditions for stability of T S fuzzy control are given. 相似文献
4.
Li Wenyuan Li Zhiping Xu Guoyu 《保鲜与加工》1991,(1):6-11
A fast dual algorithm is presented for the piecewise linear programming with successively increasing slopes. The concept of the pointer is used to derive the optimality and the feasibility conditions based on the dual simplex principle, which avoids enlarging the scale of the problem due to introducing piecewise variables so that storage and calculating requirements are reduced. Finally,the example is given to demonstrate the effectiveness of the presented algorithm. 相似文献
5.
The critical reliability slip surface with minimum value of reliability index is difficult to be obtained by the Monte-Carlo method. The simplified Bishop method was adopted to calculate the factor of safety for given circular slip surface thereby defining the performance function in reliability analysis. Six variance values of random variables were designed and four sample ranges were assumed. A quasi-Monte Carlo method was defined with fow samples. One hundred and thirty-two potential slip surfaces were randomly generated. The reliability indexes regarding those slip surfaces were calculated by Monte-Carlo method and quasi-Monte Carlo method, respectively. The comparative results show that in the case of one random variable, the reliability index from Monte Carlo method is found to be linear with that from quasi-Monte Carlo method. In the similar conditions, the wider the sample range, the smaller the tangent value of line, and Vice versa. In addition, the bigger the sample number, the bigger the tangent value of line. The Quasi-Monte Carlo method is approved to be practicable for the determination of critical reliability slip surface for homogeneous slope. 相似文献
6.
Unilateral problems is a kind of important partial differential problems. It can be solved by treating it as a complementary problem. As the complementary conditions lie in the boundary of the region,it is suitable for BEM. This paper is based on the switching algorithm,which is first used by J. M. Aitchison for the Signorini Problems of Laplace operator,then extends it to the elliptic operator,and conjunct it with the BEM. At last the detail of the algorithm is given. The new algorithm is easy to be implied effectively and quickly. It only needs the minimal change of the BEM programming. The numerical tests show the algorithm is effective and conventional. 相似文献
7.
Zhu Tianguo 《保鲜与加工》1988,(5)
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. 相似文献
8.
甲醇钠催化体系下化学法与超声法对提高脂肪酸甲酯化度影响的研究 总被引：2，自引：0，他引：2
以棕榈油和棉籽油为原料,利用甲醇钠的高活性催化合成脂肪酸甲酯(FAME),通过对FAME的2种合成方法——化学法和超声法,所得FAME的转化率,以及反应条件的比较,来研究更适合于工业化生产的合成方法。通过实验确定了化学法和超声法合成棕榈油和棉籽油脂肪酸甲酯的最佳工艺条件;并且要达到相同的FAME转化率时,采用超声法时对反应条件的要求比化学法的要求低,尤其是反应时间明显缩短,因此更适合在工业生产上应用。此外,采用二次酯化或者脱除甘油,所得到的FAME的转化率明显比一次酯化的转化率有所提高。 相似文献
9.
The Object-Oriented technology is introduced into the 3-d Numerical Manifold method(NMM). The design method and management of the Classes about the three dimensional Numerical Manifold Method are studied. The Classes are designed and the prototypes of some key classes are shown. As an example,the 3-d numerical calculation results are given. The calculation results are in good agreement with the theoretical solutions. It shows that the Object-Oriented programming of 3-d NMM is correct. 相似文献
10.
GONG Xian sheng 《保鲜与加工》1999,(3):15-23
A method which is used for calculating steady vibration response of shipping propulsion shafting connecting with a coupling with nonlinear hysteresis characteristics are studied. On condition that the nonlinear dynamic stiffness and hysteresis damping of the coupling be considered, on the basis of GLM(Galerki Levenberg Marquard) method, a method called SSGILM(Separate System Galerkin and Improved Levenberg-Marquardt)to be used for calculating steady vibration response of propulsion shafting with local nonlinear dynamic stiffness and hysteresis damping, is proposed. A simple example is given out and the analyses show that it is effective to calculate steady vibration response of the shafting with local nonlinear dynamic stiffness and hysteresis damping by SSGILM method. From initial response values given arbitrarily, the automatic search algorithm in SSGILM method can converge the given initial response values to the response values accorded with required accuracy quickly; nonlinear dynamic stiffness and hysteresis damping of the coupling have different effect on vibration response of the shafting at different range of frequency. At the area of close nature frequency of the shafting ,displacement amplitude of the shafting is bigger. Beyond the range, the characteristics of the coupling have restraint effect on vibration of the shafting. 相似文献
11.
Chen Junping 《保鲜与加工》1991,(5):123-127
The boundedness for a class of Volterra prey-predator systems is proved and the conditions of the global stability for this class are given.which are formally different from the previous conditions obtained by the same author. 相似文献
12.
This.paper derives the basic solution of elastic half-space foundation plate byHankel transform,Then its boundary integral equation of distortion is estabished,The paper discuss-es bou ndary integral equation on plate of fixxing and/or simple support boundary.Then a systemof algebraic equations for the boundary values are established.A numerical example is given , its re-sult shows that this Method is correct. 相似文献
13.
ZANG Yue long 《保鲜与加工》2000,(6):96-99
A dual reciprocity method is proposed for the analysis of fluid sloshing in time domain. With a known initial condition, by each time step, the free surface position is traced and zero stress conditions are imposed on it. If time step is small enough, the boundary conditions are considered almost on the true moving boundary. Further study is to be carried out to verify the precision of this method. 相似文献
14.
青稞籽粒中β-葡聚糖在发芽过程中的变化 总被引：1，自引：0，他引：1
确定青稞的处理条件对发芽率的影响,测定与分析发芽青稞中β-葡聚糖的含量的变化。不同温度和时间条件下,统计青稞籽粒的发芽率,并收集样品;采用苯酚-硫酸法,对不同发芽条件下青稞中的β-葡聚糖的含量进行了测定并分析。27℃浸泡6 h后,在27℃条件下培养15 h发芽率最高,在22℃培养条件下β-葡聚糖含量最高为10.01%;通过方法学考察,含量在0~1.0 mg范围内线性关系良好,回归方程为Y=3.9015X-0.0215,R2=0.9939(n=7),平均回收率为96.38%,RSD=1.53%(n=5)。以高含量β-葡聚糖为目的青稞加工,可选择在27℃条件下6 h浸泡,22℃培养发芽作为处理条件。 相似文献
15.
According to the security investment theory of Markowitz,this paper presents aCaculation method of portfolio investment under the risk minimization,and some mathematic expres-sions of the efficient frontier for portfolio investment are conducted.Based on these,the efficientfrontier is proved as a parabola,and a practical caculation process is given. 相似文献
16.
Overconstraints exist widely in planar closed chain mechanisms and mechanical systems result in a series of detrimental influences on behavior of machines, and attention is given to them by machine designer. Some analysis methods of overconstraints in planar closed chain mechanisms are presented, and more study due to the faultiness of these methods. In accordance with faultiness of two common kind of methods, formulas method and loop analysis method of degrees of freedom, and by combining these two methods, an useful mechanism overconstraints analysis method which is convenient for computer aided overconstraints analysis is gained via research on the two methods thoroughly and systematically, and some new views about mechanism overconstraints analysis are presented. 相似文献
17.
On the basis of the calculated results of accurate analytic solution of stiffened rectangular plates,the general equations of cylindrical bending of the plates with tensile forces are established for engineering practice.Its solution combining with engineering problem is given for the special defor-mation conditions of elastic supports.In the paper,the numerical example is given and compared with references,it shows that the results are available. 相似文献
18.
土地生产潜力计算方法研究 总被引：12，自引：3，他引：9
土地生产潜力是土地资源评价的重要内容之一。回顾总结了土地生产潜力的起源及发展过 程,系统的分析了土地生产潜力的研究方法,并把这些方法归纳为三类:理论计算法、经验公式法、高 产地块法,探讨了各类方法的使用条件、特点及局限性。最后对土地生产潜力研究的努力方向做了进 一步展望,提出了一些建议。 相似文献
19.
Xiong Hanwei Zhang Peiyuan 《保鲜与加工》1997,(4):31-36
A system of governing equations for spatially curved rods are derived in natural coordinate,and an analytic solution to the statically determinate problem is given.Based on the solution,a generalized displacement model for element of curved bars is developed,which is convergent and accurate. 相似文献
20.
With operator solution. recursion formula of series solution to Liouville-Hill equation is given, furthermore the paper discusses the remainder term of the series and its estimation. and the existence and uniqueness of the solution is obtianed. Next,we discuss the inital problem of the n on homogeneous Hill equation with damping terms, which is a forced oscillation problem, and the series sloution and the sufficient conditions of its convergence are also given. 相似文献