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981.
V. L. Levtov V. V. Romanov A. I. Ivanov S. B. Riaboukha V. V. Sazonov 《Cosmic Research》2001,39(2):137-149
The data of microacceleration measurements performed onboard the Mirstation are analyzed. The data were taken while testing the passive vibration-protective platform VZP-1K developed by the NPO Kompozit. We have processed the results of simultaneous microacceleration measurements on the vibration-protective platform and on the station body close to the platform. Two sets of the French equipment Microaccelerometer were used for these measurements. It was found that the platform reduces the vibrational component of microaccelerations in the band of frequencies above 3 Hz by more than a factor of 10. In this case, all harmonics with large amplitudes are damped by a factor of 50 and more, and some harmonics with small amplitude are damped only by a factor of 10. In the band 0.3–0.6 Hz (close to natural frequencies of the platform), the several-fold increase in amplitude of the vibrational component of microaccelerations is observed, but since the initial values of this amplitude in all performed experiments were small, the above indicated increase practically has not decreased the vibration-protective properties of the platform. The estimations of natural frequencies and damping coefficients of the platform found as a result of data processing of microacceleration measurements made during its free oscillations are obtained. The dependence of frequencies on the amplitude of oscillations is revealed for one mode, which testifies to appreciable nonlinear effects. 相似文献
982.
仿生物态模拟型硬件理论与关键技术研究 总被引:4,自引:1,他引:4
阐述了模拟型仿生硬件的概念、基本思想与技术瓶颈,分析了基于FPTA(Field programmable transistor array)的模拟型仿生硬件的结构与电子细胞电路工作原理。给出了模拟型仿生硬件的电路编码方案、个体电路测试评估方法和进化实现过程。提出了基于单染色体自适应变异进化机制的模拟型仿生硬件进化算法。以信号放大器、半波整流器、异或门数字电路作为典型应用实例,来验证模拟型仿生硬件的进化特性,并讨论了进化算法的参数选取、染色体适应度评估问题。仿真结果表明:所提出硬件进化算法的进化速度快、成功率高,所设计的FPTA细胞阵列可以实现模拟信号放大、信号处理和数字电路逻辑功能。 相似文献
983.
O. A. Troshichev E. E. Antonova Y. Kamide 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2002,30(12):2683-2687
Measurements of the magnetic field and low energy plasma by the GEOTAIL spacecraft have been used to study the relationship between variations of the plasma velocity and of the magnetic field in the distant (100–200 RE) and middle (40–80 RE) tail. The analysis was carried out separately for the tail lobes and the plasma sheet. It is shown that the absolute values of the magnetic field and plasma velocity, as well as their corresponding components (VX and BX, VY and BY, VZ and BZ), are linearly connected in the tail lobes. In the plasma sheet, however, the plasma velocity and the magnetic field do not seem to be related to one another. The distant plasma sheet seems to be in a regime of turbulence. The diffusion coefficients estimated from our data set of the velocity parameters in the plasma sheet are in good agreement with the theoretical predictions of Antonova and Ovchinnikov (1996, 1999). 相似文献
984.
美国国家标准和技术研究院(NIST)电磁部噪声规划提出了遥感应用例如卫星气象观测中的微波亮温度标准的研发。这个标准以现有波导系统电磁噪声基准为基础,与亮温度即辐射有关,借助一个特性很好的天线实现。热校准目标作为基准的补充,采用冗余测量的方式,用于检验或者减小不确定度。做过的26 GHz的初步测量表明所提出标准的可行性,同样太赫兹(THz)频率的研究也在进行中。对于THz噪声,用一个加热的目标作为噪声标准,虽然我们没有这么高频率的噪声基准。这个标准将与THz辐射计一起使用。辐射计基于一个接收机,该接收机采用了一个热电子测辐射热混频器,并被准光学适配器耦合到辐射中去。希望年底能够用这套系统进行THz噪声测量。 相似文献
985.
A. Galeev V. Moroz V. Linkin R. Kremnev G. Rogovsky K. Pichkhadze B. Martynov O. Papkov A. Eremenko E. Galimov Y. Surkov C. Elachi R. Bourke J. McNamee 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1996,17(12):15-20
Program MARS GLOB provides step-by-step deployment of an international network of Mars surface stations by association the MESUR NETWORK (USA), INTERMARS-NET (ESA) programs with the network of small stations and penetrators now under developing in Russia jointly with international cooperation in frameworks of the MARS-96 Project. It is offering also delivery on Mars surface two penetrators and Mars Rover. Now penetrators and Rover are developing by Russia with participation of other countries in frameworks of the MARS-98 (or MARS TOUR) Project. 相似文献
986.
O. B. Shchuko 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2004,33(12):2156-2160
The heat transfer in a regolith subsurface layer of thickness 20 m has been theoretically simulated for the areas near Mercury's north pole aiming at the clarification of the possible existence of subsurface ice formations of different form. The paper considers different models of the icy regolith structure and composition: pure uniform amorphous ice; a porous dispersive system with ice-filled pores and voids; permafrost. For comparison the heat transfer in dry iceless regolith has been considered as well. It has been shown that the line of maximum distribution of subsurface icy formations depends on the icy regolith model, but for any one in the “hot” regions it does not go below 70°. For the “cool” regions this line has been shown to go from 5° to 10° southward than that for the “hot” ones. The possible thickness of icy regolith near the pole has been estimated for different models assuming an interior heat flow of 15 mW m−2. It has been shown that the maximum thickness of this layer takes place at the pole and is equal to 10 km for any model. 相似文献
987.
A.O. Benz P. Saint-Hilaire 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,32(12):2415-2423
A popular scenario for electron acceleration in solar flares is transit-time damping of low-frequency MHD waves excited by reconnection and its outflows. The scenario requires several processes in sequence to yield energetic electrons of the observed large number. Until now there was very little evidence for this scenario, as it is even not clear where the flare energy is released. RHESSI measurements of bremsstrahlung by non-thermal flare electrons yield energy estimates as well as the position where the energy is deposited. Thus quantitative measurements can be put into the frame of the global magnetic field configuration as seen in coronal EUV line observations. We present RHESSI observations combined with TRACE data that suggest primary energy inputs mostly into electron acceleration and to a minor fraction into coronal heating and primary motion. The more sensitive and lower energy X-ray observations by RHESSI have found also small events (C class) at the time of the acceleration of electron beams exciting meter wave Type III bursts. However, not all RHESSI flares involve Type III radio emissions. The association of other decimeter radio emissions, such as narrowband spikes and pulsations, with X-rays is summarized in view of electron acceleration. 相似文献
988.
This paper presents the research results on studying the carbon dioxide concentration fields in a jet behind the swirl burners of various design. A technique of identifying the gaseous fuel and air mixture quality in the jet behind the swirl burners was developed. 相似文献
989.
Gillmann Cedric Way M. J. Avice Guillaume Breuer Doris Golabek Gregor J. Höning Dennis Krissansen-Totton Joshua Lammer Helmut O’Rourke Joseph G. Persson Moa Plesa Ana-Catalina Salvador Arnaud Scherf Manuel Zolotov Mikhail Y. 《Space Science Reviews》2022,218(7):1-21
Space Science Reviews - The BepiColombo Environment Radiation Monitor (BERM) on board the European Space Agency’s Mercury Planetary Orbiter (MPO), is designed to measure the radiation... 相似文献
990.
L. F. Chernogor 《Cosmic Research》2017,55(5):323-332
The paper describes quasi-periodic and aperiodic variations in the phase and amplitude of radio waves of LF and VLF ranges, which accompanied the flight and explosion of the Chelyabinsk meteoroid. Quasi-periodic variations in the phase have been explained by the generation of acoustic-gravity waves in the atmosphere, which modulate the electron density in the ionosphere and the phase of radio waves. Aperiodic variations in the phase and amplitude of radio waves are associated with an increase in the electron density in the lower ionosphere (at altitudes of 65–70 km). This increase was most likely caused by the interactions of subsystems in the Earth–atmosphere–ionosphere–magnetosphere system or, more correctly, by the precipitation of high-energy electrons from the magnetosphere into the lower ionosphere, which was stimulated by the flight and explosion of a cosmic body. According to the estimates, the density of the flux of electrons with energies of 100 KeV should be on the order of 106 m–2 s–1. 相似文献