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1.
Space Science Reviews - We discuss afresh the problem of the auroral electron acceleration based on the controversy reports of Bryant, D. A. et al.: 1992, Phys. Rev. Lett. 68, 37, and Borovsky, J.:... 相似文献
2.
The earth's foreshock is a region where particularly large amplitude MHD waves are commonly observed. They exhibit various
waveforms, suggesting that nonlinear interaction between the waves is in progress. In a previous paper (Hada et al., 2003) we have introduced a method to quantitatively evaluate the strength of phase coherence among the waves from a given
time series data. Here we further develop our method by applying wavelet filtering technique. From the analysis it was found
that, although the turbulence is consisted of waves with a wide range of plasma rest frame frequencies, only those frequencies
lower than the ion gyrofrequency are responsible for generating the phase coherence.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
4.
EFFECT OF THE RIBLETS SURFACE ON THE BOUNDARY LAYER DEVELOPMENT 总被引:3,自引:0,他引:3
EFFECT OF THE RIBLETS SURFACE ON THE BOUNDARY LAYER DEVELOPMENTWangJinjun;LanShilong;LianQixiang(InstituteofFluidMechanicsIBe... 相似文献
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6.
Large amplitude MHD waves are commonly found in the solar wind. Nonlinear interactions between the MHD waves are likely to
produce finite correlation among the wave phases. For discussions of various transport processes of energetic particles, it
is fundamentally important to determine whether the wave phases are randomly distributed (as assumed in quasi-linear theories)
or they have a finite coherence. Using a method based on a surrogate data technique and a fractal analysis, we analyzed Geotail
magnetic field data (provided by S. Kokubun and T. Nagai through DARTS at the Institute of Space and Astronautical Science)
to evaluate the phase coherence among the MHD waves in the earth's foreshock region. The correlation of wave phases does exist,
indicating that the nonlinear interactions between the waves is in progress.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
H. Lundstedt 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2005,36(12):2516-2523
The methods of today’s predictions of space weather and effects are so much more advanced and yesterday’s statistical methods are now replaced by integrated knowledge-based neuro-computing models and MHD methods. Within the ESA Space Weather Programme Study a real-time forecast service has been developed for space weather and effects. This prototype is now being implemented for specific users. Today’s applications are not only so many more but also so much more advanced and user-oriented. A scientist needs real-time predictions of a global index as input for an MHD model calculating the radiation dose for EVAs. A power company system operator needs a prediction of the local value of a geomagnetically induced current. A science tourist needs to know whether or not aurora will occur. Soon we might even be able to predict the tropospheric climate changes and weather caused by the space weather. 相似文献
8.
数据库开放对象的一般结构和操作 总被引:1,自引:0,他引:1
为了更精确地模拟客观世界,减少软件生成的复杂性,本文提出开放对象的数据模型,使其自身具有自组织、自我进化的能力,实质是面向对象+人工智能+数据库的一个模型。本文讨论了它的一般结构,开放对象的集合在子开放对象关系下构成有向图,并在对其加以适当限制做成偏序格的基础上,定义了一组开放对象的基本操作。 相似文献
9.
用激光多普勒技术测量了二维扩压器中不可压湍流边界层分离流动,得到了时均速度和雷诺剪应力分布。实验结果分析表明:以Coles速度律发展的Bardina速度分布可以描述瞬时间歇分离点以前和瞬时间歇再附点以后的时均速度分布,但无法描述分离区的边界层速度型。Cross速度分布可描述分离区的边界层速度分布。Cebeci&Smith涡粘性代数模型难以正确地描述分离边界层的雷诺剪应力。 相似文献
10.
通过研究柠檬酸钙酸解过程中溶液电导率的变化规律,建立了酸解体系的数学模型,提出了改革酸解工艺路线中的物料添加顺序,并用计算机自动控制物料添加量和添加速率,自动判定酸解终点的方法。 相似文献