For the case of sinusoids plus white noise, it will be proved that the construction of the LPEF (Linear Prediction Error Filter) coefficient matrix space is quite similar to that of the correlation matrix space. Therefore, the orthogonal vector techniques can be applied to the LPEF coefficient matrix space for spectral estimation. With the SVD approximation approach used for the correlation matrix, the present approach has not only the property of high resolution, but also the property of high statistic stability. finally, a one dimensional LPEF coefficient matrix is formed and the spectral estimation is simulated by computer. The results are compared with those obtained by other approaches.

The matrix D describing the relations of the loops to the nodes in the graph, the branch set based on the independent loops, and their matrix Q are defined. The theorem in which the product of the loop-node matrix D multiplied by the incidence matriÅ A_α is equal to the matrix Q is put forward and proved. The admittance matrix Y_tc of the branch set is defined, and it is assumed that the vector voltage of the branch set,V_le is a calculative quantity. So the equation of the branch set is derived and the branch set is derived and the branch set method is put forward.

Some new concepts of efficient incidence matrix, ascending order adjacency matrix and vertex end-result are introduced, and some improvements of the maximum weight matching algorithm are made. With the method, the computer program in FORTRAN lagua-ge is realized on the computers FELIX C-512 and IBM-PC. Good results are obtained in practical operations.

The generalized image method (GIM) was presented to deal with the electromagnetic scattering from anti-symmetric objects. Combined with numerical methods, it can-make the required storage and CPU time to be greatly reduced. The method was thoroughly studied in two dimensional problems and some numerical examples were given.

From the mode-matching method, by doing some transforms and derivations, the scattering and propagation integral equations for solving the problems of discontinuous dielectric structure are obtained. The necessary and sufficient condition for the existence of solution of propagating equations is given. It is really the dispersion equation of the dielectric structure. As an example, a succinct solution of one-step discontinuous dielectric structure is derived.

This paper describes a method for fast engineering evaluation of the transmission characteristics of single-mode optical fibers. A versatile microcomputer program is presented which can be utilised to analyse mode field characteristics of single-mode fibers with arbitrary refractive index profiles. Our computation shows that the mathematical method and corresponding programs developed in this paper are relatively simple and accurate enough for engineering design of sigle-mode fiber communication systems.

By means of quasi-optical method, the spatial resolving power of millimeter wave receiving system which is used in plasma diagnostics has been greatly improved. In this paper the formulas and procedures for designing a millimeter wave quasi-optical receiving system are presented and some measured results are given.

Effects of the loading dielectric on the properties of microwave ferrite devicesare calculated by means of coupling-wave theory. Some qualitative results are obtained. Theseare helpful to acquire a better understanding of dielectric-loaded mechanism for microwave ferrite devices.

The interface of Si-Ni produced by evaporation was annealed from room temperature to 800℃ and "in situ" studied by transmission electron microscopy (TEM). The formation of Ni₂Si, NiSi and NiSi₂ on chemically cleaned Si (100) and (111) surfaces has been investigated. On the basis of experimental results, SiC had been formed at 650℃ on such cleaned Si surface at 1x10^-6 mmHg vaccum; the appearance of that series of nickel silicide were not at an exact temperature; and it would be easier to epitaxy silicides on Si (111) than (100) surface.

In this paper, by means of the relationship between matrix multiplication and polynomial multiplication, and the binomial theorem, a theorem for calculating coefficients of Tustin transformation is presented. In addition, an algorithm is given.

The transconductances (g_m1s,g_m2s) and drain conductance (g_ds) of dual-gate FETs are evaluated by takinj; a dual-gate PET as a four-polar device based on current continuity and voltage conservation. This analytic method may be suitable for any kind of dual-gate FETs. The expressions of g_m1s, g_m2s, g_ds are quite clear in conception. The formulas set up the relations between single-gate FETs and dual-gate FETs, and lead to a special coupling idea of dual-gate devices. For the single-gate FET s model selected, there is a good agreement between calculated and experimental values of g_m1s, g_m2s and g_ds.

The presence of inhomogeneous distribution of defects in GaAs wafers strongly limits the reproducibility of IC fabrication processes. In this paper, we report for the first time a Fourier transformation image testing approach, called FTIT, for the two dimensional evaluation of the disorder in a wafer, as it appears in infrared transmission timages. The Fourier analysis of the cell structure reveals a dominat statistical rectangular organization of the dislocations along <110> and <010> directions. The α and β defined in the paper are typical organization of the cells to evaluate quantitatively the properties of IC materials.

A new kind of dispenser cathode impregnated with barium ytterbnate has been developed. It has good properties: high coefficient of secondary emission, stronger ability of resisting oxygen poisoning, higher thermionic emission current density and more uniform emission on the cathode surface. The cathode is suitable for use as an electron emitter for microwave tubes, especially magnetrons.