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121.
In this paper we report pulsing hiss emissions observed at the low latitude station, Jammu (geomag. lat. 22°26′N, L = 1.17) in which intensity decreases with the increase in frequency. The entire dynamic spectra contain somewhat irregular structure. To explain these we propose that the hiss emissions are generated through Doppler-shifted cyclotron interactions near the equator and propagate to the earth in the whistler-mode. Further, ULF waves present in the generation region modulate the intensity of the emission resulting in the pulsing nature. The growth rates are computed and discussed in the light of recent works.  相似文献   
122.
The observation of the directional distribution of energetic and cosmic ray particles has been done with the Voyager spacecraft over a long period. Since 2002, when the first flux enhancements of charged particles associated with the approach of Voyager 1 to the solar wind termination shock were observed, these anisotropy measurements have become of special interest. They play an important role to understand the magnetic field and shock structure and the basics of the modulation of cosmic ray and anomalous particles at and beyond the termination shock. They also serve as motivation to study the spatial behavior of galactic and anomalous cosmic ray anisotropies with numerical modulation models in order to illustrate how the radial anisotropy, at different energies, change from upstream to downstream of the termination shock. Observations made by Voyager 1 indicate that the termination shock is a complicated region than previously thought, hence the effects of the latitude dependence of the termination shock’s compression ratio and injection efficiency on the radial anisotropies of galactic and anomalous protons will be illustrated. We find that the magnitude and direction of the radial anisotropy strongly depends on the position in the heliosphere and the energy of particles. The effect of the TS on the radial anisotropy is to abruptly increase its value in the heliosheath especially in the A > 0 cycle for galactic protons and in both polarity cycles for anomalous protons. Furthermore, the global effect of the latitude dependence of the shock’s compression ratio is to increase the radial anisotropy for galactic protons throughout the heliosphere, while when combined with the latitude dependence of the injection efficiency this increase depends on modulation factors for anomalous protons and can even alter the direction of the radial anisotropy.  相似文献   
123.
Density of discontinuities in the heliosphere   总被引:1,自引:0,他引:1  
The spatial distribution of MHD discontinuities in the solar wind has been studied, based on the long time observations by the magnetometer onboard Ulysses. We emphasize the critical importance of the method whereby events are selected; some previous work is critically reviewed in this respect. Our analysis supports earlier observations that the density of discontinuities decreases with increasing distance from the Sun. It is suggested, however, that the distribution of the discontinuity normals should be revised, retaining only those discontinuities for further study that have reliable normals. This study shows that the vast majority of well defined discontinuities has a small magnetic field component parallel to the discontinuity normal. Given the large number of discontinuities in the Ulysses data set there is a statistically sufficient number for further study. It is also shown in this paper that for the subset of well defined discontinuities the determination of the normal vector using Minimum Variance Analysis and the cross-product technique are equally valid.  相似文献   
124.
创新时代,物理教学也要创新。在高等教育教学中,通过物理教学培养学生科学的创新思维能力尤为重要。  相似文献   
125.
本文探讨了工科普通物理中有关原子物理的教学内容。提出对教学内容要强调三个方面:(1)要强调基本概念与重点内容,(2)要讲清实验与新思想、新概念间的关联,(3)要介绍有关高新技术的新进展及应用前景。  相似文献   
126.
本义讨论了爱因坦斯的物理学研究纲领与他对量子力学的基本观点之间的关系。  相似文献   
127.
本文从全国各高校普遍存在的大学生心理健康的不良状况入手 ,分析了高校班主任工作的特点 ,论证了高校班主任工作的新角色应该是大学生心理健康教育的指导教师  相似文献   
128.
SOHO: The Solar and Heliospheric Observatory   总被引:1,自引:0,他引:1  
The Solar and Heliospheric Observatory (SOHO), together with the Cluster mission, constitutes ESA's Solar Terrestrial Science Programme (STSP), the first Cornerstone of the Agency's long-term programme Space Science — Horizon 2000. STSP, which is being developed in a strong collaborative effort with NASA, will allow comprehensive studies to be made of the both the Sun's interior and its outer atmosphere, the acceleration and propagation of the solar wind and its interaction with the Earth. This paper gives a brief overview of one part of STSP, the SOHO mission.  相似文献   
129.
The dramatic changes seen in the X-ray spectral and timing properties of accreting black hole candidates (BHCs) provide important clues about the accretion and jet formation processes that occur in these systems. Dividing the different source behaviors into spectral states provides a framework for studying BHCs. To date, there have been three main classification schemes with Luminosity-based, Component-based, or Transition-based criteria. The canonical, Luminosity-based criteria and physical models that are based on this concept do not provide clear explanations for several phenomena, including hysteresis of spectral states and the presence of jets. I discuss the re-definitions of states, focusing on an application of the Component-based states to more than 400 RXTE observations of the recurrent BHC 4U 1630–47. We compare the X-ray properties for the recent 2002–2004 outburst to those of an earlier (1998) outburst, during which radio jets were observed. The results suggest a connection between hysteresis of states and major jet ejections, and it is possible that both of these are related to the evolution of the inner radius of the optically thick accretion disk.  相似文献   
130.
Advances of microgravity sciences in China are introduced. The research works include ground-based study and space experiments. In the recent years, the main means still are theoretical analysis, numerical simulation, ground-based experiment, and short-time microgravity experiments of drop tower. Besides, many space experiment projects are arranged. SJ-10 recoverable satellite will carry out 19 scientific experiment projects. Nine of them are for microgravity Sciences. The other ways for space microgravity experiment are with the help of Chinese Shenzhou spacecraft, Chinese Tiangong space laboratory, and Chinese space station in the near future. The Chinese space station will become main platform of Chinese microgravity sciences experiment in space.   相似文献   
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