【简答题】桥梁动载试验的激振方法中,自振法的特点是使桥梁产生有阻尼的自由衰减振动,记录到的振动图形是桥梁的衰减振动曲线。为使桥梁产生自由振动,一般常用突加载荷和突卸荷载两种方法。( )
【判断题】若图纸中单个梁标高有特殊标注应在设置梁构件中其它属性中修改量的起点标高和终点标高。
【单选题】A key assumption of new growth theory is that
A.
all technological change is the result of luck.
B.
higher incomes lead to a higher birth rate.
C.
a successful innovator has the opportunity to earn a temporary, above-average profit.
D.
the population growth rate is lower than the real interest rate.
【单选题】梁在集中力作用的截面处,它的内力图特点是 。
【单选题】梁在集中力作用的截面处, Fs 与 M 图有下述特点:( )
【单选题】New growth theory assumes that
A.
all inputs experience diminishing returns.
B.
only random technological advances produce growth.
C.
knowledge does not experience diminishing returns.
D.
None of the above answers is correct.
【单选题】为测定水中Ca 2+ 、Mg 2+ 的含量,以下消除少量Fe 3+ 、Al 3+ 干扰的方法中,( )是正确的。
C.
于酸性溶液中加入三乙醇胺,然后调至pH=10的氨性溶液
【简答题】What is Distribution Resources Planning (DRP)?