某两端铰支空心圆截面杆,长度为,外径,内径。杆件的弹性模量为,。计算临界应力的公式有:(a)欧拉公式,(b)直线公式。试计算该压杆的临界力。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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