智能小区中的网络和布线设计解决方案——智能建筑学术讨论系列文章之七

当前小区信息网络建设中存在多种实施方案。笔者分析比较了常用的几种典型方案的优劣。讨论了目前建设中的一些解决方法，提出了兼顾现状，适度超前的设计实施原则。     

The effect of large strains on ageing of a filled elastomer

Strain endurance experiments on a filled elastomer were performed at several temperatures. It was found that superimposed prestraining accelerated the ageing process. This process was caused by microstructural changes in the elastomer. In order to evaluate the mechanical properties of a filled elastomer it is necessary to take into consideration not only the ageing effects but also the loading history.     

A new technique for on-line and off-line high speed computation

A novel technique for both online and offline computation is presented. With this technique, a reconstruction analysis in elementary particle physics, otherwise prohibitively long, has been accomplished. It will be used online in an upcoming Fermilab experiment to reconstruct more than 100000 events per second and to trigger on the basis of that information. The technique delivers 40 gigaoperations per second, has a bandwidth on the order of gigabytes per second, and has a modest cost. An overview of the program, details of the system, and performance measurements are presented     

Analysis of the Safety of the Burial Grounds of Decontamination Waste of Chernobyl Origin in the Territory of Belarus

Unsatisfactory conditions of storage of decontamination waste (DW) in the storages formed in the territory of Belarus after the Chernobyl accident require the evaluation of the level of protection of the environment and population. The potential hazard of the decontamination waste burial grounds (DWBGs) has been evaluated based on the use of a generalized multichamber model that was verified by comparing the calculation results and the results obtained by the American (GW SCREEN) model. The characteristics of the 24 largest and most hazardous DWBGs are given and the evaluations of their safety are presented. The zones of influence of these storages, whose size varies from 100 to 330 m, have been determined. The reliability of the prediction evaluation of a possible hazardous radioactive contamination of water near the storages has been verified using the Dudichi DWBG as an example.     

Solution of the Inverse Problems of Scattering of Electromagnetic Fields by Elongated Defects

We formulate the inverse problem of scattering of electromagnetic fields by thin defects and analyze numerical algorithms used for its solution. It is shown that, in the two-dimensional case, the shape of a thin defect is completely determined by the scattered field given on a certain curve for a fixed value of the wave number. For the solution of the inverse scattering problem, we propose to use the procedure of iterative regularization based on the gradient methods. We deduce expressions for the Fréchet derivative of the operator of direct scattering problem with Dirichlet conditions imposed on the surface of a scatterer.     

Ampacities of power cables wound on reels

This paper presents a mathematical model that is capable of calculating the ampacity of a wide variety of power cable designs consisting of an arbitrary number of layers on a cable reel. The model considers round cables with copper conductors. The validity and accuracy of the ampacity model were verified by comparing the predicted temperature distribution within the reel with measured temperatures collected during an extensive testing program conducted at the US Bureau of Mines (USBM). The mathematical model predicted a temperature distribution within the cable layers that was very close to the measured variation in temperature. The value of the program is illustrated by calculating ampacities for several copper conductor sizes     

Calculation and design of vibrational mills

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 1, pp. 14–15, January, 1992.     

Optimal Design of the High-Power Plate and Grid Modulated HF Amplifier by High Modulation Levels

The optimal design of the high power plate and grid modulated selective amplifier is examined in this paper. For the analysis purposes, the linear model of constant plate current characteristics for HF power triode is applied. The carrier wave state of the unmodulated amplifier is chosen so to enable the realization of the high levels of modulation. The results are obtained immediateZy, and the estimated error is acceptable. The estimated characteristic values of this high power and high efficiency HF amplifier are shown in the corresponding diagrams.