1 550 nm数字电视长距离传输网的设计和实施

在丽水市建立有线数字电视服务平台后，需要将有线数字电视传输到丽水市各县（市）、乡镇乃至农户家里，实现有线数字电视的全市覆盖。从丽水市的实际出发，提出利用SDH传输网和1550nm射频副载波调制干线光传输相结合的方法覆盖全市8个县（市）的具体方案。     

Multivariate convexity preserving interpolation by smooth functions

A set of multivariate data is called strictly convex if there exists a strictly convex interpolant to these data. In this paper we characterize strict convexity of Lagrange and Hermite multivariate data by a simple property and show that for strict convex data and given smoothness requirements there exists a smooth strictly convex interpolant. We also show how to construct a multivariate convex smooth interpolant to scattered data. Partially supported by DGICYT PS93-0310 and by the EC project CHRX-CT94-0522.     

Overlapping Schwarz waveform relaxation method for the solution of the forward–backward heat equation

In this article we analyzed the convergence of the Schwarz waveform relaxation method for solving the forward–backward heat equation. Numerical results are presented for a specific type of model problem.     

90nm工艺及其相关技术

ITRS2001规划2004年实现90nm工艺,英特尔、AMD等世界顶级半导体公司将于2003年采用90nm工艺量产微处理器和逻辑器件。这样使ITRS2001整整提前了一年。90nm工艺包括193nm光刻技术、高k绝缘材料、高速多层铜互连技术、低k绝缘材料、应变硅技术和电压隔离技术等新技术。193nm光刻技术是实现90nm工艺达量产的最关键技术,为此,必须采用193nmArFstepper(准分子激光扫描分步投影光刻机)。讨论了90nm工艺达量产的难点,如掩模版成本较高、成品率较低和应用面暂时不宽等。     

Input-to-state stability of Runge–Kutta methods for nonlinear control systems

In the paper we introduce input-to-state stability (ISS) of Runge–Kutta methods for control systems. The ISS properties of Runge–Kutta methods are studied for linear control systems and nonlinear control systems, respectively. The previously reported results in literature are special cases of ISS of Runge–Kutta methods.     

Growth factor and expected growth factor of some pivoting strategies

Several definitions of growth factors for Gaussian elimination are compared. Some new pivoting strategies, intermediate between partial pivoting and rook pivoting, are introduced. For random matrices, an approximation of the average normalized growth factor associated with several pivoting strategies is computed and analyzed. A stationary behavior of the expected growth factors of the new pivoting strategies is observed. Bounds for the growth factors of these pivoting strategies are provided. It is also shown that partial pivoting by columns produces small growth factors for matrices appearing in practical observations and for which the growth factors produced by partial pivoting are very large.     

Numerical solution of the two-dimensional Poincaré equation

This paper deals with numerical approximation of the two-dimensional Poincaré equation that arises as a model for internal wave motion in enclosed containers. Inspired by the hyperbolicity of the equation we propose a discretisation particularly suited for this problem, which results in matrices whose size varies linearly with the number of grid points along the coordinate axes. Exact solutions are obtained, defined on a perturbed boundary. Furthermore, the problem is seen to be ill-posed and there is need for a regularisation scheme, which we base on a minimal-energy approach.     

High-power CW diode-side-pumped 1341 nm Nd:YAP laser

A high-power CW diode-side-pumped Nd:YAP laser with linearly polarization at 1341 nm has been described. The laser characteristics including thermal lens and stability of flat–flat resonator were studied. By comparing the output powers at different resonator lengths and different output couplers, the c-axis polarized laser working at 1341 nm has been obtained with a maximum output power of 121 W at the pumping power of 555 W. The optical–optical efficiency is 21.8% and the optical slope efficiency is 40%. The a-axis polarized laser at 1339 nm has also been successfully obtained when the c-axis polarized laser had become instable with the increase of pumping power.     

Error bounds for rational quadrature formulae of analytic functions

We study the error of rational quadrature rules when functions which are analytic on a neighborhood of the set of integration are considered. A computable upper bound of the error is presented which is valid for a broad range of rational quadrature formulae and a comparison is made with the exact error for a number of numerical examples.This work was supported by the Dirección General de Investigación (DGI), Ministerio de Ciencia y Tecnología, under grants BFM2003-06335-C03-02 and BFM2002-04315- C02-01.