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991.
992.
In this article, a kind of auxiliary design BSA* for constructing BSAs is introduced and studied. Two powerful recursive constructions on BSAs from 3‐IGDDs and BSA*s are exploited. Finally, the necessary and sufficient conditions for the existence of a BSA(v, 3, λ; α) with α = 2, 3 are established. © 2006 Wiley Periodicals, Inc. J Combin Designs 15: 61–76, 2007  相似文献   
993.
994.
The pulsed NMR, isopiestic and pycnometric methods are applied to investigate the physicochemical properties of softwood [GOST (State Standard) 9571-89] and hardwood [GOST 28172-89] celluloses, as well as flax cellulose [GOST 10330-76, 9394-76], both in the initial state and subjected to chemical treatment. Possible changes occurring in the supramolecular structure of a polymer are analyzed. The structural and sorption characteristics of the investigated samples are calculated. Their water absorption capacities are determined.  相似文献   
995.
A novel heath monitoring system of the rocket based on fiber optic Bragg gratings is brought forward, its component units and working principle are also described.  相似文献   
996.
Ag-Bi高温超导线材转变温度的测量   总被引:2,自引:0,他引:2  
介绍了 Bi系银包套高温超导线材的电阻温度特性 ,用测电阻和电磁感应两种方法分别测量了材料的超导转变温度 ,电磁感应法测量曲线上台阶的出现表明材料中 Bi(2 2 2 3)和 Bi(2 2 12 )两相的存在。  相似文献   
997.
The paper considers the problem of constructing an efficient automatic procedure for reducing the block size in the block conjugate gradient method insuring that the resulting rate of convergence is comparable with that of the block conjugate gradient method with constant block size. The numerical results provided show that, independently of the type of distribution of the smallest eigenvalues of the preconditioned matrix, the procedure suggested always leads to a decrease of the arithmetic costs with respect to those of the block method with constant block size. Bibliography: 8 titles.  相似文献   
998.
On the example of the effect of an atmospheric wave with given amplitude on the density oscillations of minor gas constituents near the mesopause (at heights 80–90 km, we consider the influence of the quasi-resonant periodic spatial transport on a distributed system responding subharmonically to a periodic external action (diurnal sunlight variations). Numerical modeling revealed the formation of a coherent horizontal distribution of the dynamical variables (i.e., the concentrations of small constituents). Application of this effect to the mesopause conditions is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 47, No. 9, pp. 739–752, September, 2004.  相似文献   
999.
For the linear deterministic system with unknown orders and coefficients adaptive controls are given so that the closed-loop system is stabilized and the unknown parameters are consistently estimated. Moreover, if the parameter estimation is ignored, then the system input and output can be reduced to zero with an exponential rate.This project is supported by the National Natural Science Foundation of China.In Commemoration of the 15th Anniversary of the Acta Mathematicae Applicatae Sinica.  相似文献   
1000.
The well-known sine-Gordon equation, supplemented with small damping and small quasiperiodic external force, is studied under the zero Dirichlet boundary conditions at the endpoints of a finite interval. The main assumption is that all frequencies of the external force are in 1:1 resonance with certain eigenfrequencies of the unperturbed equation; i.e., the socalled fundamental multifrequency resonance is observed. It is shown that in this case, by an appropriate choice of the parameters of the external force, one can make it so that the boundary value problem has a stable invariant torus of any finite dimension that bifurcates from zero on any preassigned finite set of spatial modes. It is also shown (by numerical analysis) that in a number of cases the above-mentioned torus coexists with a chaotic attractor.  相似文献   
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