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91.
D. J. Wu 《Space Science Reviews》2005,121(1-4):333-342
Nonthermal electrons play a major role during solar flares since not only they contain a large amount of the released energy
but also they provide important information of the flaring physics through their nonthermal radiation in radio and hard X-ray
bands. In a recent work Wu (Phys. Plasmas
10 (2003) 1364) proposed that dissipative solitary kinetic Alfvén wave (DSKAW) with a local shock-like structure could provide an efficient acceleration mechanism for energetic electrons in a
low-β plasma. In the present paper dynamical characteristics of the DSKAW acceleration mechanism in solar coronal plasmas
are studied and its application to the acceleration of flaring electrons is discussed. 相似文献
92.
93.
94.
95.
针对如何获取运动平台的实时加速度和在精确跟踪加速度的同时限制位移,建立了系统动力学模型以计算加速度,使用虚拟弹簧法限制位移。在Matlab环境下,搭建了整个伺服控制系统。仿真结果表明,控制系统在保证平台位移不脱离限制区域的基础上,实现了加速度的精确跟踪。 相似文献
96.
A. Dosch A. Shalchi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
We calculate the maximum energy that a particle can obtain at perpendicular interplanetary shock waves by the mechanism of diffusive shock acceleration. The influence of the energy range spectral index of the two-dimensional modes of the interplanetary turbulence is explored. We show that changes in this parameter lead to energies that differ in at least one order of magnitude. Therefore, the large scale structure of the turbulence is a key input if the maximum particle energy is calculated. 相似文献
97.
介绍了在冲击加速度校准中,为了抑制电、机械等干扰和噪声对冲击加速度测量结果的影响,采用二阶巴特沃斯型低通滤波器,通过时间序列翻转、二次滤波等方式,实现零相移的低通滤波效果。并比较不同截止频率下,低通滤波器对衰减程度不同的冲击加速度波形产生的峰值偏差,给出不同加速度波形下,低通滤波器截止频率选择应注意的问题。 相似文献
98.
An effect of the Coriolis forces on the process of gas expansion in the turbine stage is considered. Expressions for efficiency with regard for the radial flow passage are derived. The calculation results and statistical data on the geometric parameters of diagonal stages are presented. 相似文献
99.
Evgenia V. Troitskaia Irene V. Arkhangelskaja Leonty I. Miroshnichenko Andrey I. Arkhangelsky 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
By the data on intensity-time profiles of the neutron capture line of 2.223 MeV we have studied some characteristics of two solar flares, 28 October 2003 and 20 January 2005 (INTEGRAL and CORONAS-F observations, respectively). The SINP code was applied making allowance for the main processes of neutron interactions and deceleration in the solar plasma, character of neutron source, losses of neutrons and density model of the solar atmosphere. Comparison of the computed time profiles of 2.223 MeV line with observed ones for the flare of 28 October 2003 confirms the results obtained earlier for three other flares. Namely, the effect of density enhancement (EDE) in the sub-flare region, as well as the variations (hardening) of accelerated particle spectrum in the course of the event have been confirmed. The usual modeling procedure by the SINP code, however, seems to be inapplicable to the event of 20 January 2005. Possible causes of density enhancements during some flares and peculiarities of the 20 January 2005 flare are discussed. 相似文献
100.
Marco Bassetto Andrea Caruso Alessandro A. Quarta Giovanni Mengali 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(9):2855-2864
The interaction between electromagnetic waves and matter is the working principle of a photon-propelled spacecraft, which extracts momentum from the solar radiation to obtain a propulsive acceleration. An example is offered by solar sails, which use a thin membrane to reflect the impinging photons. The solar radiation momentum may actually be transferred to matter by means of various optical phenomena, such as absorption, emission, or refraction. This paper deals with the novel concept of a refractive sail, through which the Sun’s light is refracted by crossing a film made of polymeric micro-prisms. The main feature of a refractive sail is to give a large transverse component of thrust even when the sail nominal plane is orthogonal to the Sun-spacecraft line. Starting from the recent literature results, this paper proposes a semi-analytical thrust model that estimates the characteristics of the propulsive acceleration vector as a function of the sail attitude angles. Such a mathematical model is then used to analyze a simplified Earth-Mars and Earth-Venus interplanetary transfer within an optimal framework. 相似文献