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991.
In the study of the resolvent of a scalar elliptic operator, say, on a manifold without boundary there is a well-known Agmon-Agranovich-Vishik condition of ellipticity with parameter which guarantees the existence of a ray of minimal growth of the resolvent. The paper is devoted to the investigation of the same problem in the case of systems which are elliptic in the sense of Douglis-Nirenberg. We look for algebraic conditions on the symbol providing the existence of the resolvent set containing a ray on the complex plane. We approach the problem using the Newton polyhedron method. The idea of the method is to study simultaneously all the quasihomogeneous parts of the system obtained by assigning to the spectral parameter various weights, defined by the corresponding Newton polygon. On this way several equivalent necessary and sufficient conditions on the symbol of the system guaranteeing the existence and sharp estimates for the resolvent are found. One of the equivalent conditions can be formulated in the following form: all the upper left minors of the symbol satisfy ellipticity conditions. This subclass of systems elliptic in the sense of Douglis-Nirenberg was introduced by A. KOZHEVNIKOV [K2]. 相似文献
992.
关于Lipschitz强增生算子的迭代程序 总被引:42,自引:0,他引:42
本文在一般的Banach空间中讨论Lipschitz强增生算子方程解和严格伪压缩算子不动点的迭代逼近问题.我们的结果统一和推广了Deng,Liu,Tan和Xu的结果,完整地回答了Chidume提出的公开问题. 相似文献
993.
994.
一类新的k-次增生型变分包含解的存在性及其具有混合误差项的Ishikawa迭代逼近 总被引:1,自引:0,他引:1
在实自反Banach空间中,引入和研究了一类新的k-次增生型变分包含问题,证明了这类变分包含解的存在性、唯一性及其具有混合误差项的Ishikawa迭代程序的收敛性.本文结果本质地改进、发展和统一了张石生和曾六川等人的一系列相关结果. 相似文献
995.
企业发展的多目标决策模糊优化模型 总被引:4,自引:1,他引:3
企业多目标决策优化是企业生产管理以及发展的一项非常重要的工作 .企业生产管理以及发展受多种因素影响 ,而且企业的多目标决策优化问题具有模糊性 ,本文将针对其模糊性 ,运用模糊数学理论进行研究 ,并给出具体应用实例 ,其结果令人满意 ,且具有较强的可靠性和实用性 相似文献
996.
Wu Xiaofei Sun Liyan 《Annals of Differential Equations》2007,23(2):218-224
This paper,using the theory of exponential dichotomy and fixed point theo- rem,discusses the existence of periodic solution for a class of neutral higher dimensional differential system with delay,the result extends and improves the result of paper[6]. 相似文献
997.
StudyingtheMode-SpectraCharacteristicsofAnAbove-ThresholdBiasedSemiconductorLaser¥XIAGuangqiong;WUZhengmao;CHENJianguo;LUYucu... 相似文献
998.
A bistable optical device was demonstrated by using the longitudinal mode hopping of the laser diode and the narrow transmission spectrum of an interference filter. The device is capable of converting changes in the wavelength of the laser diode into changes in intensity by transmitting it through the filter. Exclusive OR operation was observed with the use of triple signal outputs. In addition, an optical switch-off phenomenon was confirmed by directly injecting a pulse 500 ps wide into an external dye laser. 相似文献
999.
O. I. Mokhov 《Theoretical and Mathematical Physics》2007,152(2):1183-1190
We prove that the associativity equations of two-dimensional topological quantum field theories are very natural reductions
of the fundamental nonlinear equations of the theory of submanifolds in pseudo-Euclidean spaces and give a natural class of
flat torsionless potential submanifolds. We show that all flat torsionless potential submanifolds in pseudo-Euclidean spaces bear natural structures
of Frobenius algebras on their tangent spaces. These Frobenius structures are generated by the corresponding flat first fundamental
form and the set of the second fundamental forms of the submanifolds (in fact, the structural constants are given by the set
of the Weingarten operators of the submanifolds). We prove that each N-dimensional Frobenius manifold can be locally represented
as a flat torsionless potential submanifold in a 2N-dimensional pseudo-Euclidean space. By our construction, this submanifold
is uniquely determined up to motions. Moreover, we consider a nonlinear system that is a natural generalization of the associativity
equations, namely, the system describing all flat torsionless submanifolds in pseudo-Euclidean spaces, and prove that this
system is integrable by the inverse scattering method.
To the memory of my wonderful mother Maya Nikolayevna Mokhova (4 May 1926–12 September 2006)
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 152, No. 2, pp. 368–376, August, 2007. 相似文献
1000.
Wenxiang Wang Guofen Yu Meisheng Xu Yubin Gong 《International Journal of Infrared and Millimeter Waves》2003,24(5):661-668
The design of a 8mm TE
13 mode gyrotron is given in this paper. Discussions about the selection of the dimensions of the RF structure and electron gun are presented. Calculated results of the operating parameters of the gyrotron are also given. At 37.5GHz, pulse power 56kW is obtained for the gyrotron manufactured according to our design. Mode pattern obtained by scorching method shows that the mode of the output millimeter wave is TE
13. 相似文献