爱因斯坦的这篇论文里面，在不可压缩流体中一点(x0,y0,z0),当单独考虑流体在三个相互垂直方向做膨胀运动的基本运动时，为什么会假设有u0=A(x-x0),v0=B(y-y0),w0=C(z-z0),且由液体连续不可压缩就有A+B+C=0?貌似这个式子和欧拉的连续不可压缩流体的微分方程很像，到底有何联系？
如果是对(x，y,z）处运用泰勒级数展开，且只考虑了一阶项，不应该是设成u=A(x-x0),v=B(y-y0),w=C(z-z0)吗？
We also assume that the velocity components of asurface element of the sphere coincide with the corresponding velocity components of the adjacent liquid particles, i.e.,that the contact layer (imagined to be continuous) also displays a coefficient of viscosity that is not infinitesimally small.这句看了半天没弄懂，黏度的定义不是速度梯度吗？为神马只要有相同组成的速度，黏度就是有限值？
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如果是对(x，y,z）处运用泰勒级数展开，且只考虑了一阶项，不应该是设成u=A(x-x0),v=B(y-y0),w=C(z-z0)吗？
We also assume that the velocity components of asurface element of the sphere coincide with the corresponding velocity components of the adjacent liquid particles, i.e.,that the contact layer (imagined to be continuous) also displays a coefficient of viscosity that is not infinitesimally small.这句看了半天没弄懂，黏度的定义不是速度梯度吗？为神马只要有相同组成的速度，黏度就是有限值？
I
