亚密湍流等离子体尾迹的雷达散射特性

对亚密湍流等离子体尾迹的雷达散射特性进行了分析、研究和计算。讨论了圆柱形等离子体尾迹径向厚度、雷达波入射频率和入射角等因素对雷达散射截面的影响。尾迹中散射场的计算采用矩阵法求解,用一阶畸变波Born近似完成亚密湍流等离子体尾迹雷达散射截面积（RCS）的计算。分析和计算结果表明,雷达波入射频率和入射角、尾迹的径向厚度对RCS值影响较大,并且计算所得的尾迹雷达散射截面方向图可为再入体的雷达识别和隐身提供帮助。     

Oscillatory Behavior of Ventilation in Resting Man

Section I discusses the results of analyses conducted on time records of ventilation, for periods up to five hours, for young adult male subjects in a conscious minimal power state. The results imply the following: 1) Temporal patterns of ventilation are characterized by the superposition of a denumerable set of almost periodic sustained oscillations with time dependent and stochastic variations. 2) Different subjects exhibit the same number of deterministic components within similar ranges of frequency. 3) A typical pattern contains cycles with nominal periods on the order of one minute, four, nine, twenty, forty minutes, and two and one-half hours with deviations in period and amplitude due to inherent non-stationarity and random fluctuations, especially at higher frequencies. 4) Resting state ventilation oscillates about the mean with an amplitude on the order of half the mean.     

上胶机粘度控制

本文论述了含浸工段胶液粘度控制的原理和方法。     

Oscillatory Behavior of Respiratory Gas Exchange in Resting Man

This study deals with the dynamics of respiratory gas carbon dioxide concentration are three, ten, twenty, and thirty to forty-five minutes and two hours; in oxygen concentration, three, ten, twenty, and thirty minutes and one and four hours; and in respiratory quotient, one, five, ten, and fifteen minutes and two to four hours. exchange in resting man. Spectral analyses are performed on time series representing four-hour continuous records of ventilation, carbon dioxide release, oxygen takeup, end tidal carbon dioxide concentration, end tidal oxygen concentration, and respiratory quotient. Results imply that the temporal behavior of each of these six variables can be characterized by a superposition of a finite set of self-sustained almost periodic oscillations with periods in the range from one minute to four hours and time dependent stochastic variation. In ventilation, carbon dioxide release, and oxygen takeup, individual components have amplitudes of between five and ten percent of mean values and nominal periods of one, four, ten, and twenty minutes and one and two to four hours. Components in oxygen concentration, carbon dioxide concentration, and respiratory quotient have amplitudes of between two and four percent of mean values.     

Comparison between Equivalent Charge Model and Equivalent Dipole Model on Realistic Head Model

Equivalent source layer(ESL) imaging is an important kind of high-resolution electroencephalogram(EEG) imaging.It consists of two categories:equivalent dipole layer(EDL) and equivalent charge layer(ECL).Both of them are assumed to be located on or near the cortical surface and have been proposed as high-resolution imaging modalities or as intermediate steps to estimate the epicortical potential.Here,EDL and ECL based on a realistic head model are presented,both simulations and real data experiment are done to compare these two models.The results show that ECL can provide higher spatial resolution about source location than EDL does.     

视频粘滞效应的产生及预防

本文根据2006年8月8日卢龙电视台在硬盘播出过程中出现的视频粘滞现象及其成因--视频粘滞效应进行了具体的分析,并提出了相应的预防措施和应急解决办法.     

Oscillatory characteristic temperature of InAs quantum-dot laser

An InAs quantum-dot laser showed continuous-wave lasing up to 323 K. A high T₀ of over 1000 K was measured below 130 K. The value of T₀ rapidly declined at higher temperatures, and showed an oscillatory behavior above 250 K. The oscillatory changes of T ₀ were accompanied by alternating change in the light output versus current curves above the threshold, suggesting possible participation of higher states in lasing     

Circuits with Oscillatory Hierarchical Farey Sequences and Fractal Properties

We present two dual oscillating circuits having a wide spectrum of dynamical properties but relatively simple topologies. Each circuit has five bifurcating parameters, one nonlinear element of cubic current–voltage characteristics, one controlled element, LCR components and a constant biasing source. The circuits can be considered as two coupled oscillators (linear and nonlinear) that form dual jerk circuits. Bifurcation diagrams of the circuits show a rather surprising result that the bifurcation patterns are of the Farey sequence structure and the circuits’ dynamics is of a fractal type. The circuits’ fractal dimensions of the box counting (capacity) algorithm, Kaplan–Yorke (Lyapunov) type and its modified (improved) version are all estimated to be between 2.26 and 2.52. Our analysis is based on numerical calculations which confirm a close relationship of the circuits’ bifurcation patterns with those of the Ford circles and Stern–Brocot trees.     

Equivalent linear and nonlinear discrete-time systems

Equivalence of certain classes of nonlinear and linear (higher-order) discrete-time systems is established through a transformation of variables. The nonlinearity assumed for the case of the 1st-order system is the discrete-time version of the well-known Riccatian nonlinearity.     

Nonreversibility and Equivalent Constructions of Multiple-Unicast Networks

We prove that for any finite directed acyclic network, there exists a corresponding multiple-unicast network, such that for every alphabet, each network is solvable if and only if the other is solvable, and, for every finite-field alphabet, each network is linearly solvable if and only if the other is linearly solvable. The proof is constructive and creates an extension of the original network by adding exactly s+5m(r-1) new nodes where, in the original network, m is the number of messages, r is the average number of receiver nodes demanding each source message, and s is the number of messages emitted by more than one source. The construction is then used to create a solvable multiple-unicast network which becomes unsolvable over every alphabet size if all of its edge directions are reversed and if the roles of source-receiver pairs are reversed     

等效变换的推广应用

提出了利用等效变换把受控源的受控支路等效为电路或电阻与电压源串联组合的方法来求解含受控源的线性电路,推广了等效变换在含受控源线性电路中的应用。     

无线局域网中的有线等价保密算法

介绍无线局域网协议802．11和802．11b用到的一种加密算——WEP(Wired Equivalent Privacy),即有线等价保密算法。     

Equivalent noise generators in JG FET

Van der Ziel has shown that at high frequencies the gate noise of a field effect transistor increases rapidly with increasing frequency. This effect is attributed to the thermal noise of the conducting channel and is caused by the capacitive coupling between the channel and the gate. Experimentally this effect can be shown to be negligible up to 3 MHz for n-type FET's 2 N 3966 where the cut off frequency is about 100 MHz. Experimental variation of the input noise current generator of the FET is then deduced.     

时域分析中的等效激励和状态跳变

在信号与系统的时域分析中,经典教材采用等效电路法或冲激匹配法来求解初始状态的跳变.对于从输入因果分量和0+状态计算系统响应的问题,经典教材采用待定系数法求解响应.不同于它们,本文使用与初始条件等效激励的概念,计算从0-到0+的状态跳变,并使用等效激励通过系统对应的规范化系统的等效激励法,由输入因果分量和0+状态计算系统响应.本文的方法具有计算过程简单规范、物理概念清楚的优点.     

等离子烧结与等离子活化烧结

等离子烧结具有烧结速率极快、烧成温度高以及能量利用效率高等优点而成为新一代很有潜力的烧结工艺。本文对等离子烧结的发展与现状及其工作机理进行了综述。等离子烧结用于陶瓷及其复合材料尚处于起步阶段，但它必定会成功地用于新材料的制备。     

Viscosity and optical measurement on fluoride glasses

Scattering loss and viscosity against temperature measurements have been carried out on fluoride glasses. The results indicate for the first time a ?-4 behaviour for scattering loss in the 0.45?0.75 ?m wavelength range. Activation energies for viscous flow were found to be similar for both ZrF4? and HfF4?based glasses.     

Equivalent mobility traffic in circular and linear cellular arrays

Traffic behaviour in circular and linear cellular arrays is investigated. A model for fixed velocity mobiles is introduced. It is shown that the cellular network traffic is independent of the number of cells in the circular array case and that, compared with non-mobility in both linear and circular arrays, mobility factors such as cell size, call holding time and velocity of mobiles have considerable impact on probabilities of call blocking. As a result, the notion of ‘equivalent mobility traffic’ is introduced and its behaviour is investigated. A fixed point method for the analysis of probability of blocking is presented. Results are compared with simulations. © 1998 John Wiley & Sons, Ltd.