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Effects of gravity waves on the distributions of O_3.and OH in the mesopause region

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chinese Science Bulletin 2001年第15期46卷 1265-1268页

作者： XU Jiyao & MA Ruipinglaboratory for Space Weather, Center for Space Science and Applied Research, chinese academy of sciences, beijing 100080, China {3., chinese academy of sciences, beijing 100080, China laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China laboratory of numeric study of heliospheric physics Chinese Academy of Sciences Beijing China

A dynamical-photochemical model of atmospheric gravity waves is used to study the influences of gravity waves on distributions of atmospheric minor species through transportation and photochemical reactions. We mainly study the effect of gravity waves on the distributions of atmospheric trace gases through the nonlinear photochemical reactions. O3.and OH are taken as examples in this note. The calculations indicate that the effect of gravity waves on the distributions of atmospheric trace gases is mainly through the nonlinear photochemical reactions in the mesopause region. The contribution of the nonlinear photochemical reaction caused by gravity waves can exceed the nonlinear transportation and the eddy diffusion.

关键词： gravity wave photochemical reaction coupling between photochemistry and dynamics.

A tentative study for the prediction of the CME related geomagnetic storm intensity and its transit time

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Science China(Technological sciences) 2005年第6期48卷 648-668页

作者： ZHAO Xinhua1,2 & FENG Xueshang1,3.1. SIGMA Weather Group, Key laboratory of Space Weather, Center for Space Science and Applied Re-search, chinese academy of sciences, beijing 100080, China 2. Graduate School of the chinese academy of sciences, beijing 10003., China 3. School of Geophysics and Geoinformation Systems, China University of Geosciences, beijing 100083. China 1. SIGMA Weather Group Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the chinese academy of sciences 100039 Beijing China 3. School of Geophysics and Geoinformation Systems China University of Geosciences 100083 Beijing China

Using 80 CME-ICME events during 1997.1―2002.9, based on the eruptive source locations of CMEs and solar magnetic field observation at the photosphere, a current sheet magnetic coordinate (CMC) system is established in order to study the propagation of CME and its geoeffectiveness. In context of this coordinate system, the effect of the eruptive source location and the form of heliospheric current sheet (HCS) at the eruptive time of CME on the geomagnetic storm intensity caused by CME and the CME’s transit time at the Earth is investigated in detail. Our preliminary conclusions are: 1) The geomagnetic disturbances caused by CMEs tend to have the so-called “same side-opposite side effect”, i.e. CMEs erupt from the same side of the HCS as the earth would be more likely to arrive at the earth and the geomagnetic disturbances associated with them tend to be of larger magnitude, while CMEs erupting from the opposite side would arrive at the earth with less probability and the corresponding geomagnetic disturbance magnitudes would be relatively weaker. 2) The angular separation between the earth and the HCS affect the corresponding disturbance intensity. That is, when our earth is located near the HCS, adverse space weather events occur most probably. 3. The erupting location of the CME and its nearby form of HCS will also affect its arrival time at the earth. According to these conclusions, in this context of CMC coordinate we arrive at new prediction method for estimating the geomagnetic storm intensity (Dstmin) caused by CMEs and their transit times. The application of the empirical model for 80 CME-ICME events shows that the relative error of Dst is within 3.% for 59% events with Dstmin≤?50 nT, while the averaged absolute error of transit time is lower than 10 h for all events.

关键词： coronal mass ejections, current sheet magnetic coordinate system, geomagnetic storm intensity, transit time, prediction method.

The Best Possible Metropolis Type Algorithm

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The Best Possible Metropolis Type Algorithm

流体力学与行星际物理学中激波动力学问题求解新论

第二十四届中国控制会议

作者： Peng Hu, Haitao Fang Key laboratory of Systems and Control, academy of Mathematics and Systems Science chinese academy of sciences,{3., 100080, P.R.China

For a Metropolis type algorithm with finite but large parameter choices, the least average number of steps to reach the optimal states could be regard as a optimal criterion for this algorithm. This paper introduce the Markov decision processes (MDP) to study the optimal parameter choice of the Metropolis algorithm. We show the optimal parameter of the algorithm can be obtained by solving a MDP problem. Some numeric examples are presented.

关键词： Metropolis type algorithm Markov decision processes least average step numbers to the optimal states.

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吉首大学学报 1999年第3期20卷 1-8页

作者：冯学尚魏奉思中科院日球物理数值开放研究实验室空间科学与应用研究中心北京100080

针对激波问题的求解 ,深入研究了流场及其导数跨跃激波面的跃变应满足的关系 ,其结果是得到联系激波前后流场与激波速度、方向的无穷维动力学系统 ,它实质上是反映激波全部信息的激波前后物理量空间导数与激波速度、方向的相容性关系 ,... 详细信息

针对激波问题的求解 ,深入研究了流场及其导数跨跃激波面的跃变应满足的关系 ,其结果是得到联系激波前后流场与激波速度、方向的无穷维动力学系统 ,它实质上是反映激波全部信息的激波前后物理量空间导数与激波速度、方向的相容性关系 ,可以称为广义Rankine -Hugoniot跃变条件 ,有望为流体力学。

关键词：激波动力学流体力学行星际物理 R-H跃变条件

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行星际闪烁(IPS)研究新进展

天文学进展 2000年第3期18卷 209-215页

作者：马振国张喜镇韩文焌中国科学院空间科学与应用研究中心北京100080 中国科学院国家天文观测中心北京100012

太阳风行星际闪烁（ｉｎｔｅｒｐｌａｎｅｔａｒｙｓｃｉｎｔｉｌｌａｔｉｏｎ，ＩＰＳ）研究在太阳物理、日地空间物理和空间天气学研究中具有重要科学意义。经过近３０年重点研究太阳风后，从９０年代初开始，ＩＰＳ研究在太阳风与... 详细信息

太阳风行星际闪烁（ｉｎｔｅｒｐｌａｎｅｔａｒｙｓｃｉｎｔｉｌｌａｔｉｏｎ，ＩＰＳ）研究在太阳物理、日地空间物理和空间天气学研究中具有重要科学意义。经过近３０年重点研究太阳风后，从９０年代初开始，ＩＰＳ研究在太阳风与日球观测的对比分析、行星际扰动与地磁活动预报、观测数据的层析分析三方面都取得了新的进展。

关键词：太阳太阳风行星际闪烁观测

Modulation of Galactic Cosmic Rays During the Recent UnusualSolar Minimum

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Modulation of Galactic Cosmic Rays During the Recent Unusual...

第十四届全国日地空间物理学术研讨会

作者： Lingling Zhao1 Gang Qin1 Ming Zhang2 (Center for Space Science and Applied Research, chinese academy of sciences, beijing, China1 Florida Institute of Technology, Melbourne, FL,United State2)

During the recent solar minimum the intensity of Galactic cosmic rays （GCRs） at Earth was measured at the highest ever recorded since the space age. It is known that both the interplanetary magnetic field （IMF） strength and the solar wind speed were very low, but the tilt angle of heliospheric current sheet （HCS） was not at the lowest level. This indicates that the modulation of cosmic ray is not dominated by the mechanism of particle drift through the current sheet during this A ＜ 0 cycle as we normally think. Possible reasons for the record level of cosmic ray flux might be the slower solar wind speed, weaker magnetic field, or closer termination shock radial distance due to smaller solar wind pressure. A slower solar wind speed will reduced the amount of adiabatic cooling while a weaker magnetic field will enhance particle drift and possibly diffusion. We use a GCR transport model in 3.D heliosphere with numerical simulation of Markov stochastic process to study these parameters. Finally, we will compare the numerical results with the observations to find the reasons.

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高速列车用铝合金材料的耐撞性数值分析

铁道机车车辆 2003年第A2期23卷 40-44页

作者：刘金朝王成国房加志铁道科学研究院研发中心北京100081 中国农业大学北京100083

利用有限元软件ABAQUS进行高速列车用铝合金材料的耐撞性数值分析。分析了钢和铝合金薄壁圆柱在轴向力作用下的动力学响应。所有的参数,如弹性模量,密度,屈服应力取自文献[6]中的试验数据,在相同的条件下,通过比较两者的数值结果验证了... 详细信息

利用有限元软件ABAQUS进行高速列车用铝合金材料的耐撞性数值分析。分析了钢和铝合金薄壁圆柱在轴向力作用下的动力学响应。所有的参数,如弹性模量,密度,屈服应力取自文献[6]中的试验数据,在相同的条件下,通过比较两者的数值结果验证了参数正确性和可靠性。碰撞能量一定,对应于不同的碰撞速度,比较了钢和铝合金薄壁圆柱受到的平均作用力,以及它们最后变形的塑性铰的个数。数值试验表明,在碰撞能几乎全部被吸收的情况下,对于不同的碰撞速度5、3.、65、80m/s钢材薄壁圆柱比铝合金薄壁圆柱所受到的平均作用力大,变形后塑性铰的个数少。

关键词：高速列车铝合金耐撞性数值分析有限元薄壁结构塑性铰