Theoretical Study on Ion Escape in Martian Atmosphere

Based on the observation that Martian magnetic moment is gradually reducing from the ancient to the present, we investigate the O^＋ ion flux distribution along magnetic field lines and the ion escaping flux in Martian tail with different assumed Martian magnetic moments. The results show that the O^＋ ion flux along magnetic field lines decreases with distance from Mars; the ion flux along the field line decreases more quickly if the magnetic moment is larger; the larger the magnetic moment, the smaller the ion escaping flux in the Martian tail. The ion escaping flux depends on Z-coordinate in the Martian tail. With decrease of the magnetic moment, the ion escaping flux in the Martian tail increases. The results are significant for studying the water loss from Mars S uFface.     

高压固相反应法合成具有理想Ruddlesden-Popper结构的Ca4Mn3O10层状化合物

 采用高压下的固相反应方法,成功地合成了具有空间群I4/mmm的理想三层结构化合物Ca₄Mn₃O₁₀。用电子显微学方法对此结构进行了研究,并提出了近似的结构模型。基于提出的模型,进行了电子衍射图和高分辨像的模拟,并与实验结果进行了比较。     

Transport property of polyaniline and its molecular weight dependence

Ｔｈｅｅｌｅｃｔｒｉｃａｌｃｏｎｄｕｃｔｉｖｉｔｙ(σ)ｏｆｐｏｌｙａｎｉｌｉｎｅ(ＰＡｎ)ｄｏｐｅｄｗｉｔｈｉｎｏｒｇａｎｉｃｐｒｏｔｏｎｉｃａｃｉｄｓｉｓａｂｏｕｔ10Ｓ/ｃｍａｎｄσ(Ｔ)∝ｅｘｐ[-(Ｔ0/Ｔ)1/2].Ｉｔｍｅａｎｓｔｈａｔσｉｎｃｒｅａｓｅｓｗｉｔｈｉｎｃｒｅａｓｉｎｇｔｅｍｐｅｒａｔｕｒｅａｎｄｔｈｅｔｒａｎｓｐｏｒｔｐｒｏｐｅｒｔｙｉｓｉｎａｃｃｏｒｄａｎｃｅｗｉｔｈｔｈｅｖａｒｉａｂｌｅｒａｎｇｅｈｏｐｐｉｎｇ(ＶＲＨ)ｍｏｄｅｌ[1].Ａｆｔｅｒｓｔｒｅｔｃｈｉｎｇ,ｔｈｅＨＣｌｄｏｐ…     

MgB_2超导体块材的高压合成

利用高压烧结的方法成功地合成出块状MgB2 超导体。所获得的样品具有良好的单相性。低温磁性测量实验和电阻测量实验均表明样品具有高于 39K的超导转变温度。实验结果表明 ,高压合成是制备和研究MgB2 新型金属间化合物超导体的一种非常有效的手段     

磺化SIS及其离聚物的稀溶液性质

嵌段共聚物;比浓粘度;特性粘液;磺化SIS及其离聚物的稀溶液性质     

等离子体反常输运性质的量纲分析

反常输运现象是实验室等离子体和空间等离子体中的重要过程．该文运用量纲分析方法研究了无碰撞磁化等离子体的反常输运性质,得出反常电导率、反常扩散系数、反常热导系数和背景物理量之间的明显关系式．结果表明,反常扩散系数具有玻姆扩散系数形式,反常热导系数具有Ｎ_αＴ_α／ｅＢ形式,电导率表达式也符合实验结果．     

聚乙烯接枝马来酸酐极稀和稀溶液性质的研究

该文研究了聚乙烯接枝马来酸酐 (PE g MAH)在极稀和稀浓度范围内的溶液行为 .两个区间内的粘浓关系都呈直线关系 ,但极稀区间的斜率比稀浓度的大得多 .两者的交点C 为临界接触浓度 .随着接枝率的增大 ,比浓粘度逐渐增大 .温度升高也使比浓粘度增大 .     

Bifurcated Current Sheet Structure in a Quiet Time by Cluster Spacecrafts

We analyse the vertical structure of the magnetotail current sheet for two time intervals during which the Cluster spacecrafts crossed the neutral sheet in a quiet time. In the intervals, the current sheet moved slowly, and the value of the AE index was relatively small, about 40-130 nT. We find two examples of current sheets, with the current density maximum at the magnetic equator （Bx = 0）, as well as an example of off-centre or bifurcated current sheets. In the quiet time, without any fast plasma flow and without significant flapping motion, we also directly observed the bifurcated current sheet. The bifurcated current sheet is probably associated with instabilities in the current sheet. These may be important for researching the mechanism of current sheet bifurcation.     

Analysis of the Interaction between Low-Frequency Waves and Ions in the High-Altitude Cusp Region Observed by Satellite Cluster

The energy transfer between ions （protons） and low frequency waves （LFWs） in the frequency range f1 from 0.3 to 10 Hz is observed by Cluster crossing the high-altitude polar cusp. The energy transfer between low frequency waves and ions has two means. One is that the energy is transferred from low frequency waves to ions and ions energy increases, The other is that the energy is transferred from ions to low frequency waves and the ion energy decreases. lon gyratory motion plays an important role in the energy transfer processes. The electromagnetic field of f1 LFWs can accelerate or decelerate protons along the direction of ambient magnetic field and warm or refrigerate protons in the parallel and perpendicular directions of ambient magnetic field, The peak values of proton number densities have the corresponding peak values of electromagnetic energy of low-frequency waves. This implies that the kinetic Alfven waves and solitary kinetic Alfven waves possibly exist in the high-altitude cusp region.     

块体金属玻璃Zr46.75Ti8.25Cu7.5Ni10Be27.5的超导与负电阻温度系数

测量了块体金属玻璃Zr_46.75Ti_8.25Cu_7.5Ni₁₀Be_27.5在退火前后其电阻值随温度的变化,测量的温度范围为1.5—300K.样品在退火前后都发现有超导现象.零磁场下其超导转变温度T_c分别为1.84和3.76K.在5—300K温度范围内,原始样品具有负的电阻温度系数.如果取Zr, Ti, Cu, Ni及Be分别贡献出1.5, 1.5, 0.5, 0.5及两个传导 关键词： 块体金属玻璃 超导 电阻温度系数