Dr Perelman proved Poincaré's conjecture by taking an equation normally used to model heat dissipation in three-dimensional objects, known as Ricci flow.

佩雷尔曼博士利用广为人知的“瑞奇流（Ricci flow）”这样一个热方程来证明了庞加莱猜想。

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Based on experimental models, the paper sets up three-dimensional steady heat transfer and flow physical model and mathematical model on a three polluting heat sources after simplification.

本文在实验模型的基础上，经简化建立了有三个污染源的置换通风三维稳定传热、流动的物理模型和数学模型。

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A three-dimensional numerical analysis model of fluid flow and heat transfer in pulsed current TIG weld pool is developed.

对运动电弧作用下脉冲t IG焊接熔池流场与热场动态变化过程建立了三维数学模型。

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