The trouble with this statistic is that America has lots of sources of R&D spending: federal money accounted for only $86 billion of the $288 billion that it spent on R&D in 2004.
不过这个数据有问题，因为美国研发支出的资金来源很多，比如2004年，研发总支出为$2880亿，而财政支出不过$860亿。
The general elastic modulus of the dam is back analyzed by using the statistic model, hybrid model and the 3-D FEM analysis result.
应用统计模型、混合模型以及三维有限元的计算分析成果，反演了坝体的综合弹性模量；
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