目的：研究描述湍流对流中大尺度磁场演化的湍流输运系数。研究方法：我们使用的测试场方法与三维数值模拟的湍流对流与剪切和旋转计算湍流输运系数描述的大尺度磁场的演变在运动学制度的平均场论。一维平均场模型与推导出的湍流输运系数进行比较，直接模拟。结果：α效应随着旋转的增加而单调增加。湍流扩散系数eta_t与湍流垂直速度的平方成正比。而eta_t的减少近似成反比的场的波数，α效应和湍流泵浦表现出更复杂的行为。在存在剪切和无旋转的情况下，诱导了小的α效应，其似乎不显示作为剪切的函数的任何一致的趋势。如果剪切足够大，这个小的α能够激发平均场模型中的发电机。负责驱动剪切电流效应的系数显示了几个符号的变化作为深度的函数，但也能够有助于发电机行动的平均场模型。在这些情况下的增长率远低于直接模拟表明，一个不相干的α-剪切发电机也可能在他们的行动。如果旋转和剪切都存在，α效应更加明显。剪切流和Omega x J效应的组合也比仅剪切的情况下更强，但低于α-剪切发电机。直接模拟的结果是一致的平均场模型，其中所有这些影响都考虑到，而不需要调用非相干效应。
英文摘要：
(abridged) Aims: To study turbulent transport coefficients that describe the evolution of large-scale magnetic fields in turbulent convection. Methods: We use the test field method together with 3D numerical simulations of turbulent convection with shear and rotation to compute turbulent transport coefficients describing the evolution of large-scale magnetic fields in mean-field theory in the kinematic regime. 1D mean-field models are used with the derived turbulent transport coefficients to compare with direct simulations. Results: The alpha-effect increases monotonically as rotation increases. Turbulent diffusivity, eta_t, is proportional to the square of the turbulent vertical velocity. Whereas eta_t decreases approximately inversely proportional to the wavenumber of the field, the alpha-effect and turbulent pumping show a more complex behaviour. In the presence of shear and no rotation a small alpha-effect is induced which does not seem to show any consistent trend as a function of shear. If the shear is large enough, this small alpha is able to excite a dynamo in the mean-field model. The coefficient responsible for driving the shear-current effect shows several sign changes as a function of depth but is also able to contribute to dynamo action in the mean-field model. The growth rates in these cases are well below those in direct simulations suggesting that an incoherent alpha-shear dynamo may also act in them. If both rotation and shear are present, the alpha-effect is more pronounced. The combination of the shear-current and Omega x J-effects is also stronger than in the case of shear only, but subdominant to the alpha-shear dynamo. The results of direct simulations are consistent with mean-field models where all of these effects are taken into account without the need to invoke incoherent effects.
