共查询到20条相似文献,搜索用时 734 毫秒
1.
A. Rueda 《Space Science Reviews》1990,53(3-4):223-345
A rigorous detailed review of the concepts and calculations behind the acceleration of particles by the electromagnetic zero-point field is presented. The acceleration is enhanced in regions of great size and low particle density. Astrophysical scenarios are suggested and discussed and cosmological possibilities are briefly outlined. It is shown that the acceleration follows both from a semiclassical approach in the manner of Stochastic Electrodynamics and from quantum theory with a zero-point field that most naturally (but not necessarily) may be interpreted as time-symmetric in the manner of the Wheeler-Feynman form of Quantum Electrodynamics. It is shown that both approaches yield essentially identical results.Glossary of Abbreviations ABT
Absorber theory
- ALE
Abraham-Lorentz equation
- AM
Acceleration mechanism
- BME
Braffort-Marshall equation
- CE
Cosmic expansion
- CED
Classical electrodynamics
- CR
Cosmic rays
- EAS
Extensive air showers
- EHD
Einstein-Hopf drag
- EHM
Einstein-Hopf model
- EM
Electromagnetic electromagnetism
- FT
Field theory
- GZ
Greisen-Zatsepin
- GZE
Greisen-Zatsepin effect
- HO
Harmonic oscillator
- IC
Inverse-Compton
- ICRC
International cosmic-ray conference
- IGM
Intergalactic medium
- IGS
Intergalactic space
- ISS
Interstellar space
- LDE
Lorentz-Dirac equation
- LHS
Left-hand side
- LI
Lorentz-invariant
- MB
Maxwell-Boltzmann
- QED
Quantum electrodynamics
- QM
Quantum mechanics
- RHS
Right-hand side
- RJ
Rayleigh-Jeans
- SE
Schrödinger equation
- SED
Stochastic electrodynamics
- SM
Stochastic mechanics
- SNR
Supernova remnant
- SS
Solar system
- UHE
Ultrahigh energies
- ZBW
Zitterbewegung
- ZPE
Zero-point energy
- ZPF
Zero-point field
- XRB
X-ray background 相似文献
2.
Wei-Chun Wang Scholtz R.A. 《IEEE transactions on aerospace and electronic systems》1995,31(2):670-684
An infinite impulse response (IIR) inverse filter structure is presented, and compared with the performance of two finite impulse response (FIR) designs. The IIR design is shown to provide better performance and be able to improve further (e.g., -1.4 dB in sidelobe levels per unit delay increase for the length-13 Barker sequence) by increasing delay. The performance parameters of this IIR inverse filter suggest a design criterion for sequences on which the filter operates; that is related to the roots of the Z transform polynomial of the sequence. The sidelobe-optimal sequence derived according to this criterion is shown to provide sharper sidelobe reduction (-6 dB per unit delay increase for the sidelobe optimal length-13 sequence) 相似文献
3.
The acquisition problem for binary delay-lock loops is re-examined. Previous results obtained by Spilker and Gill on the maximum allowable search rate are shown to be in error. New results are given for the 2-? loop with video correlation and the 1-? loop with video and envelope correlation. 相似文献
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Space Science Reviews - The possibility of producing γ-rays in a close binary system is examined. First the case of systems containing a young pulsar is discussed. It is shown that high energy... 相似文献
5.
Three pulse-width modulation (PWM) control schemes for a single-phase power-factor-correction (PFC) AC/DC converter are presented to improve the power quality. A diode bridge with two power switches is employed as a PFC circuit to achieve a high power factor and low line current harmonic distortion. The control schemes are based on look-up tables with hysteresis current controller (HCC) to generate two-level or three-level PWM on the DC side of diode rectifier. Based on the proposed three control schemes, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage, and two capacitor voltages on the DC bus are controlled to be balanced. The simulation and experimental results of a 1 kW converter with load as well as line voltage variation and shown to verify the proposed control schemes. It is shown that unity PFC is achieved using a simple control circuit and the measured line current harmonics satisfy the IEC 1000-3-2 requirements 相似文献
6.
超声振动载荷下合金的疲劳寿命性能研究 总被引:3,自引:0,他引:3
应用超声共振试验技术研究了三种工程常用合金(Udimet500,174PH和Ti-6Al-4V)在超声振动载荷(f=20kHz,R=-1)下的疲劳寿命性能,并与常规疲劳载荷(f=20-50Hz,R=-1)下材料的有关性能做了对比分析。研究结果表明,材料的超声疲劳寿命性能与其动态振动特性、机械响应以及载荷体制有关。 相似文献
7.
The transient responses during the initialization phase of a first-order ?-? tracking filter and a second-order Kalman filter are evaluated as a function of radar measurement accuracy and the probability of receiving valid data at the prescribed intervals. Monte Carlo simulation results are complemented by analysis of the filtering processes and curves are presented which clearly define the deterioration in filter performance attributable to reduced probabilities of data acquisition. In addition, the responses of ?-? and Kalman filters are shown to be identical when the ?, ? gains are selected optimally. 相似文献
8.
L.R. Moyer D.S. Purdy 《IEEE transactions on aerospace and electronic systems》2002,38(1):300-301
For original paper see D.S.Purdy, ibid., vol.37, no.1, pp.285-7 (2001). It is shown that by selecting a different time variable, the approximations the author claims to be in error are indeed accurate. A reply by D.S.Purdy to these comments is included. 相似文献
9.
Moschopoulos G. Mei Qiu Pinheiro H. Jain P. 《IEEE transactions on aerospace and electronic systems》2003,39(2):660-674
A pulsewidth modulated (PWM) full-bridge converter that simultaneously performs input power factor correction (PFC) and DC-DC conversion is proposed. The converter is the same as the standard voltage-fed PWM full-bridge converter with a diode-bridge low-pass filter front end, but with a slight modification that results in an improvement in power factor that is sufficient to satisfy the EN61000-3-2 requirements for electrical equipment. The operation of the converter is explained and analyzed, and the results of the analysis are used to determine the converter's steady-state characteristics, which are discussed in detail. A design procedure for the selection of components is then derived and demonstrated with an example. The feasibility of the converter and its ability to satisfy EN61000-3-2 requirements on electrical equipment is shown with results obtained from an experimental prototype. 相似文献
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The radio observations of Venus are reviewed and compared with theoretical microwave spectra computed for a variety of models of the Venusian environment. The models considered are (a) a CO2-N2 atmosphere, (b) an atmosphere of dust (the aeolosphere model), and (c) a cloud model with various loss mechanisms in the cloud. The effect of polarization on the surface emissivity has been included in all the computations. It is shown how the radio observations place limits upon the acceptable models, for example, the density and size of dust particles required in the aeolosphere model. It is shown how some models place severe restrictions on radar observations at short centimeter wavelengths, thereby emphasizing the importance of such experiments. These same models show that the Mariner II observations can not be interpreted in terms of surface phenomena and provide a new interpretation for the microwave phase effect.This work was supported in part by the U.S. Army, Navy and Air Force under Contract DA36-039-AMC-03200(E); and in part by the National Aeronautics and Space Administration (Grants NsG-250-62 and NsG-419). 相似文献
12.
本文根据航天部标准《固体火箭发动机测量不确定度的评定》(QJ1275-87)方法,分析综合了“固体火箭发动机0.5%高精度测试系统”推力测量相对总不确定度,结论为0.3%,为全面贯彻该部标提供了应用实例. 相似文献
13.
热压烧结法制备Cf/SiC陶瓷基复合材料研究 总被引:2,自引:1,他引:2
以有机硅先驱体聚碳硅烷为粘结剂,采用热压烧结工艺,制得了Cf/SiC陶瓷基复合材料,并对其三点弯曲强度进行了测试和分析,结果表明:该工艺方法可方便的制得强度较高的陶瓷基复合材料单向板;其三点弯曲强度与试样的高跨比有很大关系,高跨比越大,弯曲强度越小;当高跨比为0.073时,材料弯曲强度为475.1MPa,断裂功为4.47kJ/m^2;材料的应力-应变曲线与普通陶瓷不同,表现塑性变形的非线性弹性特征 相似文献
14.
Gerlach K. Kretschmer F.F. Jr. 《IEEE transactions on aerospace and electronic systems》1991,27(1):83-91
For pt.I see ibid., vol.26, no.1, p.44-56, Jan. 1990. Theorems and relationships associated with the convergence rate of the Gram-Schmidt (GS) and sampled matrix inversion (SMI) algorithms are presented. Two forms of the GS canceler are discussed: concurrent block processing and sliding window processing. It is shown (as has been stated by other researchers) that the concurrent block processed GS canceler converges rapidly to its optimal signal-to-noise ratio. However, it is also shown that the result is deceptive in that the output residue samples may be highly correlated, which would significantly degrade postdetection processing. It is demonstrated that a specific form of a sliding window GS canceler has the same convergence properties as the concurrent block processed GS canceler 相似文献
15.
Effective use of military cellular automata such as military data array processor (MilDAP) and geometric arithmetic parallel processor (GAPP), in weak, subpixel target detection is shown to be possible by using new signal processing regimes based on binary ranking filter theory. By using binary ranking filters, the MilDAP can furnish 6 dB of processing gain against white Gaussian noise while monitoring from one to four million potential target tracks at 10-40 frames/s. GAPP is shown to be capable of monitoring 3.7 million tracks over 216×384 detectors at 14000 frames/s and, in a time sharing mode, 15 million tracks over 432×768 detectors at 24 frames/s. The special case of threatening targets is discussed, as well as alternate cellular architectures which use multidimensional binary ranking filters in multidimensional coordinate systems 相似文献
16.
某些零件,例如压气机工作叶片,预镀镍层被镉污染,影响装机使用.通过各种工艺试验和分析表明,镉污染是由于镀镍槽液中含镉,最终导致采用某些材料加工的零件镉脆断裂.而有些材料加工的零件在一定工艺条件下镉、镍形成金属间化合物,所以不会产生镉脆断裂. 相似文献
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An extended sample matrix inversion (SMI) algorithm can be used for minimizing the mse (mean-squared error) between the output of an N-element adaptive array and a desired reference signal. This algorithm is shown to yield mse within 3 dB of minimum (on the average) after (2N - 1) observations of the antenna element outputs. 相似文献