There iss strong vibration in the draft tube of a Francis turbine or axial flow fixed blade propeller hydraulic turbine when the turbine is running on part loading.

混流和轴流定浆式水轮机在部分负荷下运行时，尾水管中常出现较为强烈的振动。

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Under the plan, knives with blades that are 2.36 inches or shorter and less than a half-inch wide will be allowed in airline cabins so long as the blade is not fixed or does not lock into place.

CNN: U.S. to keep restriction on small knives on planes for now

Under the new rules, which go into effect April 25, knives with blades that are 2.36 inches (6 centimeters) or shorter and less than a half-inch wide will be allowed in airline cabins so long as the blade is not fixed or does not lock into place.

CNN: TSA chief faces critics, says new knife policy will stand

In their simplest form, a piece of wood is spun around a fixed axis, and pieces of the material are chipped off with a blade.

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