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71.
72.
W.Q. Gan T. Watanabe 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1997,20(12):2319-2322
Using the observational data of Bragg crystal spectromater on Yohkoh for the period from October, 1991 to the end of 1995, we have made a statistical study for the flares which show to be in a single loop or a single loop dominated in the SXT images. It is found that although the blue asymmetry is very common during the impulsive phase, the number of events with great total blueshift is very small. It is also found that the blueshift for most flares appears at the early impulsive phase and is temporally correlated with the broadening of the line. 相似文献
73.
飞机钣金零件弯边自动展开系统 总被引:1,自引:0,他引:1
由于飞机钣金件的复杂性,普通钣金展开软件不适合该类弯边零件的展开.本文分析了飞机钣金零件独有的特征,研究开发了基于CATIA环境下的飞机钣金零件的弯边自动展开系统,提出了一套特有的法向截面展开方法和下陷处理方法,并以实例说明零件的展开过程. 相似文献
74.
介绍了自动扫描磨粒形态分析仪运动系统的设计、关键技术的解决途径及制造过程中的关键工艺问题的研究成果. 相似文献
75.
简述人工智能,多媒体和灵境技术的由来和发展,重点介绍了仿真领域应用这三项技术的最新动态。探讨了应用过程中的关键技术或存在的问题。 相似文献
76.
本文运用二维约化摄动方程推导出彗尾剪彻磁流体的修正B-KdV方程,并定性讨论了其非线性性态。主要结论是:(1)推导出彗尾剪切磁流体修正的B-KdV方程,(2)给出彗尾宏观非线性波动与剪切背景的制约关系,(3)定性地解释了彗尾等离子体的一些复杂结构,(4)给出太阳风与彗尾等离子体相互作用的一种输运机制。 相似文献
77.
本文主要研究了应力场下锯切切削力的特点。试验证明在拉应力场下锯切工件比普通锯切工件的锯切力小,使切削更加有利、高效。 相似文献
78.
Nan Zhang He-sen Tang Jin Chang He-qi Zhang Wei-qun Gan Fu-yuan Gu Qi-zhong Shen Yin-lin Xu Ming-sheng Cai Yi-zhong Gong 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,32(12):2579-2583
Preliminary observing achievements by the Super Soft X-ray Detector and the γ-ray Detector in the fields of cosmic gamma-ray bursts, solar X-ray, bursts and cosmic X-ray/γ-ray background radiation are summarized. The detectors are aboard the spacecraft Shenzhou-2 that was launched on 2001 January 10. The scientific mission and general situation of the instruments are briefly described. 相似文献
79.
The recent discovery of high concentrations of hydrogen just below the surface of Mars' polar regions by Mars Odyssey has enlivened the debate about past or present life on Mars. The prevailing assumption prior to the discovery was that the liquid water essential for its existence is absent. That assumption was based largely on the calculation of heat and mass transfer coefficients or theoretical climate models. This research uses an experimental approach to determine the feasibility of liquid water under martian conditions, setting the stage for a more empirical approach to the question of life on Mars. Experiments were conducted in three parts: Liquid water's existence was confirmed by droplets observed under martian conditions in part 1; the evolution of frost melting on the surface of various rocks under martian conditions was observed in part 2; and the evaporation rate of water in Petri dishes under Mars-like conditions was determined and compared with the theoretical predictions of various investigators in part 3. The results led to the conclusion that liquid water can be stable for extended periods of time on the martian surface under present-day conditions. 相似文献
80.
W.Q. Gan Y.P. Li X.X. Yu L. Feng 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2003,32(12):2471-2476
The M4.0/SF flare on 17 March 2002 is a good example of the early observations with RHESSI. We presenthard X-ray images, light curves and energy spectra of individual hard X-ray sources, the spatial relationship between the hard X-ray sources and the H emission regions, and comparisons of light curves observed by RHESSI and GOES. We found that the picture exhibited by RHESSI is consistent with the general cartoon of a solar flare. In particular, we showed that the hard X-ray image spectra could be explained by a power-law electron beam with a lower energy cutoff Ec. The derived Ec could be as high as 40 keV, larger than the usually value of 20 keV. 相似文献