Some engineering problems, especially those involving fluid free surface, are nonlinear in boundary conditions.

其中不少问题是非线性的，如带自由面的流动区域，边界条件即呈非线性。

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The free amino acids in the cystic fluid of Cysticercus cellulosae were studied.

研究了猪囊虫囊液中的游离氨基酸。

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Its purpose is to promote free trade and the fluid movement of goods, peoples, and currency.

CENTERFORSECURITYPOLICY: The uncertain future of Mercosur

Famous for his tactile and sensual fluid forms, he takes his inspiration from nature to create an organic minimalism that he calls "fat free" design.

CNN: Biography: Ross Lovegrove