最新刊期
卷 ， 期 2 ， 1981
- 摘要：In this paper a general method for decoding BCH codes beyond the BCH bounds is intrpduced. Using multiple subsets of consecutive syndromes, matrix A is set up. Then the coefficient of a error location polynomial may be obtained by solving a set of linear equations. Thus the difficulty[3] when s≥4 is overcome.2|32|10更新时间：2025-12-08
- 摘要：Tzeng and Zimmermann showed that the Goppa codes with L=GF（qm）, g（z）=[（z-β1） （z -β2）]a （a≥1） become cyclic after being extended by an overall parity check. Recently, Tzeng and Yu showed if a = l the Goppa codes with L=GF （qm） can be extended to cyclic codes, then g（z） is quadratic. In this paper, a further necessary condition is presented. Therefore the sufficient and necessary conditions for extending Goppa codes with L = GF（qm） to cyclic codes are found.2|29|0更新时间：2025-12-08
- 摘要：general source sequence with side information （ref. Fig-1）.Definition 1: A source sequence with side information S（n）, is said to be （R（n）, D（n））-compound, if there exist δ<n)→0（δ（n）>, and a sequence Z0（n）Z（n）,such thati） P（n） （Z0（n））>l-δ（n）;ii) For each z（n）∈Z0（n）, there exists a set B（n）（z（n））Y（n）, such that | B（n）（z（n）） | ≤2w where w = R（n）（1+δ（n））, and P{A（n）（z（n））/z（n）}>l-δ（n）; where A（n）（z（n）） = {x（n）, P（n） [x（n）,B （n）（z（n））]≤D（n）)}Definition 2: The S（n） is said to be （F（n）, D（n））-information bounded, if there exist e（n） →0, and conditional probability Q（n）（y（n）/x（n））, so that the joint distribution p（n） (x（n）, z（n）, wherei（x,y/z） = log[p（x,y/z）/p（x/z）p（y/z）Theorem 1: The necessary and sufficient condition for a source sequenc with side information S（n） to be （R（n）, D（n））-compound, is for the S（n） to be （R（n）, D（n））-information. bounded.From Theorem 1 and the law of large numbers, we may derive in an easier way the coding theorem for stationary or unstationary sources with memory.2|112|1更新时间：2025-12-08
- 摘要：On the basis of analysis of the two valued logic simulation and the three valued logic simulation, a new logic system, six valued logic system, is suggested. There exist some disadvantages if the two valued logic simulation is adopted, because the transient state of gate is neglected. There are also some restrictions in three vaclued logic simulation as x = x. As for the six valued logic simulation, these disadvantages can be overcome. It could be said that the two valued logic system is an efficient approach to analyse the behavior of the digital logic system in the steady state, while the six valued logic system is an efficient approach to analyse the bahavior of the digital logic system even if it is in the transient state.2|11|6更新时间：2025-12-08
- 摘要：in this paper, the resolving power limit with the SEM television pick-up tube at low light levels is calculated by use of quantum noise theory. Ways to improve the resolving power limit and the theoretical limitation for measurement are investigated.First, it is shown that, without the electrical noise of the television system, there exists in the television picture a theoretical resolving power limit at low light levels because of the presence of light quantum noise, its value depending on the photo quantum effect of the SEM photocathode and the modulation transfer function of television system.Next, in consideration of the existence of television system noise, the paper shows that the actual resolving power limit at low light levels is much lower than the theoretical value, and it can be improved by increasing the target gain.Finally, experimental results are given, and these results are found to agree favorably with the theoretical values as developed in this paper.2|31|0更新时间：2025-12-08
- 摘要：A super gain transistor is trial-manufactured by polycryslalline-emitter technology, It’s HFE value is kept about 2000 when Ic varied from 1mA to 20nA.2|21|2更新时间：2025-12-08
- 摘要：This article studes gain and phase characteristics of a parametric amplifier with the emphasis on phase characteristic.In this paper influence of pumping frequency and power variantion on gain and phase characteristic of the parametric amplifier is characterized by a mathematical model of all differential multiple argument function. And variation rates of phase of parametric amplifier with pumping frequency and power are defined respectively as θ’f p and θ’p. Thus influence of pumping frequency and power on phase characteristic of the parametric amplifier can be separated and studied individually, analysti-cal result, formulae and experimental methods are obtained.These formulae may be used to estimate both systematic phase error and random phase error of parametric amplifier.In this article, an experimental model of three parametric amplifiers with one pumping sourse is presented. It’s gain and phase characteristic of signal frequency, influence of pumping frequency and power on gain and phase characteristic of the parametric amplifier, relative phase shift difference between two channals are also given.2|26|0更新时间：2025-12-08
- 摘要：In this work, we derived the formula of Dλ* of intrinsic photocon, under conditions of which τn=τp and the restriction on infinite optical absorption had been removed, but the effect of the surface recombination was taken into account.The τPEM appears in the Dλ* formula, but it’s influence, being very small, can be neglected.The calculation shows that, for normal surface recombination velocity, the optimum thickness of p-type InSb at 77°K is about 3μm. In addition, the detectivity of the sample mentioned above increases as the majority carrier concentration decreases. Owing to the BLIP limit, the excessive reduction of concentration is not only difficult but also unnecessary.2|17|3更新时间：2025-12-08
- 摘要：In this paper, the coupling between discrete hole on the broad walls of two parallel rectangular waveguides is studied. Optimum characteristic limitation of single hole （or hole-pair） in the [u1, u2] band is obtained: the optimum coupling smoothness ismin the maximum limit of minimum directivity in the band is（dB）It was proved that: the circular holes cannot fulfill the two optimum limits simutaneously. The conditions of optimum single hole （or hole-pair） should beIn general, there exsists the following inequalitywith optimum limit of the bandwidth2|44|2更新时间：2025-12-08
- 摘要：The operating system DJS200/XT1G is a general drum operating system designed for the computers DJS200/20 and DJS200/10. This paper discribes the structucre and the implementation of the operating system. The function of XT1G is realized by a kernel and a number of processes which are placed at various hierarchical levels. The synchronization mechanisms adopted are mainly communication primitives, also the priority schedule approach and the read/write list primitives are introduced The resource scheduling uses different algorithms for various resources of the system. The structure can guarantee the. correctness, efficiency and adaptability of the system. This paper shortly presents the key points of the implementation of the system. Finally, a multiprogramming example is given.2|32|1更新时间：2025-12-08
- 摘要：Properly grouping the smooth coefficients in the data smoothing to make the smooth coefficients equal in each group will considerably decrease the total times for multiplying operations in the smoothing operation. This paper presents the methods for grouping data-smoothing in the q-order polynomial approximation on the arbitrary points. And the errors of the grouping data-smoothing are compared ’with the errors of the conventional data-smothing in the polynomial approximation.2|100|1更新时间：2025-12-08
- 摘要：A generalized theoretical model of statistically designed antenna arrays is proposed and it is shown that all known forms of weighted antenna arrays become special cases of this theory. It is then proved that these known array forms which can give a predetermined average antenna pattern are all included without exception.2|54|2更新时间：2025-12-08
- 摘要：昗hen the intensive light is incident uniformly upon the photocathode deposited on the inner wall of the bulb, the electricfield distribution of the emitter surface will make the crystals electrolytically dissociated and force the positive ions to move along the direction of the field that results in a photo-fatigue.This paper discusses the relation between the electric-field of the layer surface and the fatigue, and presents a calculating model of positive ion displacement of photocathode, which makes some practical phenomena interpretable in the experiments.2|22|1更新时间：2025-12-08
- 摘要：<正> 编辑同志: 贵刊1978年第二期发表的“电子束泵浦异核型XeF准分子激光器的实验研究”一文（以下简称该文）,是在我不知情的情况下由署名于该文的前面两位作者撰写发表的。我作为这项研究的主要参加者,自始至终负责了脉冲发生器的调试工作,对该文关于脉冲源等的论述,感到有一些值得商榷之处,其中主要有如下几点供读者以及该文撰写人参考。 1.关于该文第94页4—6行中……实验采用电流脉冲前沿小于Ins的毫微秒高压脉冲电流经Blu-2|10|0更新时间：2025-12-08
- 摘要：A new method of phase feeding is suggested. The method of shifting and weighting is characterized by applying quantized phase margin of one element to the phase of the next element through shifting after weighting it in amplitude. Beam-pointing accuracy can be maintaind with one-time phase feeding. The devices required are simple. The new method can reduce cost, increase sweep speed and performance of antenna.2|93|5更新时间：2025-12-08
- 摘要：A new concept of auto-selection of colours by R. G. B. electron beams in a colour kinescope is described. By avoiding the customary shadow mask structure of ordinary kinescope, its weight is reduced approximately by 1/8, and its beam power reduced more than 80%.2|10|0更新时间：2025-12-08
- 摘要：The condition for implementing FIR filters with exact linear phase is derived once again in this paper. Results of the work are not contradictory with previous studies, but freque-. ncy samples can be a real sequence, so that it is advantageous to the implementation of FIR frequency sample filters.2|162|1更新时间：2025-12-08
- 摘要：Laser alloying on n-type GaAs by Q-switch ruby pulsed laser （6943A, 30ns） With energy desity 1.1-2.9J/cm2 is introduced The dependence of contact resistivity on laser energy density, carrier concentration, pulse number and alloy composition was investigated. The experimental results are given to show that satisfied contact resistivity can be obtained with four compositions which is similar or even better than that of the thermal alloying. The topography is more uniform and smooth after laser alloying with optimum energy density.2|27|1更新时间：2025-12-08
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