Abstract:This paper is a phase report of the study concerning the subject"Throttling Cavitation Venturi". To improve controle accuracy of the throttling engine，the linear throttling cavitation Venturi with a movable，specially shaped part is used. In our work，the shape of the movable part has been verified to be a rotational paraboloid，which has been proved by tests. The technique to design such a Venturi which makes the relationship between the f1ow rate and the moving distance be linear is presented. For the convenience of designing，some relations between parameters are given and Some problems concerned are discussed. This report may be a reference for those who are engaged in the development of variable-thrust liquid propellant rocket engines and liquid Venturi f1owmeters.

Abstract:Three phenomenons，occurring in the experiment of φ90 subscale engines，have been studied，i.e，a) unbounding of the grain to plastic tube to insulate; b) rising of the aft section of the pressre-time history，and c) the precipitating of Al₂O₃ particles on the throat of the nozzle. The paper derives for mulae of estimating the effects of the precipitate on the history as the burning grain is in smoking. The designs to overcome the unbounding and precipitating have been shown.

Abstract:This treatise ana1yses the re1ative aberrations in optical automatic design. It discusses the treatment of different re1ative states in the two aspects of programs' design and its use，and points out the effective ways to avoid re1ations and to go out of ill-states. It a1so states the theoretìca1 base of the ways.

Abstract:This article derives an approximate analytic solution of the wave of the early-stage electromagnetic pulse in the region of nuclear explosion source. The wave characteristics of the early-stage electromagnetic pulse corresponds with that of the γ-ray source. Comparing the analytic result with the related numerical simulation result，they accord with each other fairly well. This solution provides theoretical basis for understanding the wave characteristics of the γ-ray source by measuring electromagnetic pulse.

Abstract:This paper presents a brief theortical analysis of the so-called three-element method，a short-cut formula for analyzing first-order networks，and then，applying the results to second-order networks，derelops some short-cut formulae for solving zero-input responses and zerostate responses in various cases. These formulae are referred to as six-element method. As in the case of three-element method，here one need not write any differential equations and make any differential and integral calculations. By making only some simple algebraic calculations，the responses of second-order networks can be obtained. For comparison，some examples are provided.

Abstract:This paper briefly relates the investigation of colour 1iquid crysta1 film with encapsulations as well as the principle and the measured results of the colour thermal display images. The film is conveniently used to analyse the distribution of the several fields. It is also used as avisual estimate method of a11 sorts of the thermal effects. The applicability of the film will be wide. Its spreading will be very valuable.

Abstract:This paper considers the K dimentional dyadic expansion of composite pseudorandom code waveform function in Galois (qⁿ) finite field by the use of number transform，and bui1ds up a simple and available mathematical model. The expansion method，basis function and properties of sequency spectrum have been analyzed. As an example for its application，this paper provides the method of analyzing problems of composite pseudorandom codes with the use of this expansion. These problems contain the correlation function，the power spectrum，the spread spectrum and the dual matched filtering with progressing step by step.

Abstract:In this paper，the secant algorithm-a hardware algorithm of the computer to evaluate approximation of the functions at high speed is suggested. First，the definition of the secant algorithm is described and its scheme is discussed. Then，an improvement of the secant algorithm is given，and an economical method of the structure of the initial va1ue table is recom mended. Finally，the application of the secant algorithm to the design of hardware of the computer is discussed.

Abstract:In this paper，we examined the decision problems in a linear languages (for short LL) and Sequential languages (for short SL) for a Substitution. Following results are proved： Theorem 3 The problems of determining of given LL's (or SL's) L₁ and L₂ whefher or not there exists a substitution f mapping regular sets into regular sets is undecidable. Corollary 4 They are all undecidable to determine of arbitrary LL's (or SL's) L₁ and L₂ whether or not a f so that f(L₁)=L₂，where i) f is a homomorphism，or ii) f is a substitution，or iii)f is a ε-free substitution，or iv) f is a k-limited erasing substitution，or v) f is a generalized sequential machine，or vi) f is a complete sequential machine.

Abstract:In this paper，first，We introduce a methed for computation of two-dimensional DFT by inverse Polynomial Transforms (When k₂ is odd or oven，We discuss respectively). Then We develop mixed algorithm to compute two-dimensional DFT，the arithmetic operand of this technique for the N×N(N=2^t) two-dimensional DFT is Mu=?N²log₂N—?N²+N Ad=2N²log₂N. As Compared with the conventional radix-2 two-dimensional FFT,this mixed algorithm requires less number of multiplications (decrease by 20-40%) and same number of additions.

Abstract:A method for systematically constructing Fast Walsh Transform algorithms is given，This method is applicable to binary-ordered Walsh-，Paley-，Sequency-ordered Walsh-Kaczmarz-and Kronecker-ordered Walsh-Hadamard Transformations.Using this method，some FWT algorithms already known from literature can be presented in a novel way by means of certain matrix factorizations，As the transformations are normally done with the aid of a digital computer，it is important to establish effective and time-saving computer algorithms.

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