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中国工业化发展态势分析:1981~2001 总被引:4,自引:0,他引:4
本文利用时序全局主成分分析法对1981~2001年中国的工业化发展作了动态描绘,结果表明,1981~2001年中国的工业化发展处于整体攀升并伴有小幅波动态势。动态轨迹与客观实际能较好的吻合,可为中国工业化进一步健康发展提供参考依据。 相似文献
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无网格方法与有限元法或边界元法耦合是无网格方法处理边界条件的方法之一,在无网格方法中研究无网格方法与有限元法或边界元法耦合的研究显得非常重要.本文在无单元Galerkin法和边界元法的基础上,基于无单元Galerkin法子域和边界元法子域的界面上位移连续和面力平衡条件,提出了一种新的无单元Galerkin法和边界元法的直接耦合方法,对弹性力学问题详细推导了在整个求解域上的耦合公式.与以往的耦合法相比,这种方法简单直观,不需要增加新的耦合区域,也不需要建立新的逼近函数来保证界面位移的连续性.算例结果表明,该方法具有较好的计算精度. 相似文献
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Spectrum evolutions of spontaneous and pump-depleted stimulated Brillouin scatterings in liquid media 下载免费PDF全文
A theoretical model for calculating spontaneous and stimulated
Brillouin scattering(SBS) spectra is described. An empirical formula
for the Stokes output spectral linewidth, a function of spontaneous
Brillouin linewidth and the exponential gain coefficient, is
obtained by the calculated data fitting. The formula holds true for
two cases involving pump undepletion and depletion. The lineshape
change from spontaneous to highly pump-depleted SBS spectra is also
investigated. The result shows that for the pump power below the SBS
threshold, the Stokes output spectral lineshape evolves from
Lorentzian to approximately Gaussian as the pump power increases.
For the pump power near or beyond the threshold, the SBS spectrum is
in the form of a steady Gaussian profile, and the spectral linewidth
comes to a certain value about 7 times narrower than the spontaneous
one. The theoretical results are experimentally demonstrated by
using several common liquid media. 相似文献
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