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问题 单项选择题

10层框架-剪力墙结构，抗震设防烈度为8度，Ⅱ类场地，设计地震分组：第一组。首层层高 6m,2层层高4.5m，3-10层层高3.6m，总高度39.3m。质量和刚度沿高度分布比较均匀，各楼层重力荷载代表值Gi如题图所示。各楼层框架的D值及剪力墙等效刚度如下表所列。采用侧移法协同工作计算在连续均布荷载作用下结构假想顶点位移μT=uqH4/100Elw，并已知当结构刚度特征值λ＝1.2时位移系数u=8.07。结构阻尼比ξ＝0.05。

假定结构自振周期为T1＝0.793s，结构底部由水平地震作用产生的总弯矩标准值M0（kN·m），与（）项数值最为接近。

A．137981

B．194018

C．154368

D．202112

答案

参考答案：A

解析：

T1=0.793s＞Tg

由《建筑抗震设计规范》(GBJ 50011—20011)5.2.1

FEK=a10.85Geq=a1×0.85Geq

=0.077×0.85×89 500

=5858kN

(2)根据《建筑抗震设计规范》5.2.1，

当Tg=0.35s及T1=0.793s＞1.4Tg=1.4×0.35=0.49s时，顶部附加水平地震作用系数由表3.3.7得：

δn=0.08T1+0.07=0.08×0.793+0.07=0.133

顶部附加水平地震作用标准值按公式5.2.1-3得：

△Fn=δnFEK=0.133×5858=781.7kN

(3)各楼层的水平地震作用标准值，按公式3.3.7-2计算：

其中FEK (1-δn)=5858×(1-0.133)=5079.0kN

各楼层的水平地震作用标准值计算列于下表

(4)结构底部由水平地震作用产生的弯矩标准值为：

Mo=∑FiHi=137 981kN·m

故选A

解答题

下图是兔和狼的牙齿分化示意图，请根据图回答：

（1）______是兔的牙齿，______是狼的牙齿．

（2）兔和狼的牙齿分化不完全相同，产生这种差异的主要原因是：兔是草食性动物，它的[______]______形状像凿子适于______；[______]有宽阔的咀嚼面适于______；狼是肉食性动物，它的牙齿还有锋利的[______]______，可用于______．
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阅读理解

Years ago while lying in my hammock（吊床）and drinking JD from the bottle, I noticed my dog dragging something under the fence. Upon inspection, to my disappointment, I realized it was the next door neighbor’s 10 – year – old daughter’s rabbit. For years I had watched her come home from school and head straight out to its cage, free it and play with it in the yard. I knew that day would be no different and fearing for our dog, I had to think fast.

The rabbit was quite dirty, as if it had put up quite a struggle, so I washed it, combed it with the dog brush and blew it dry with the leaf blower. Upon finishing its grooming I jumped the fence and replaced it back in its cage hoping its death would be written off as “natural caused”.

Back to the hammock and JD. Within the hour the neighbor’s Volvo pulled in as usual and out popped the little girl, and as usual she headed straight for the cage. Only this time she stopped about six feet away and screamed: “D—A—D—D—Y!!!”.

Her father, panic stricken, stood looking at the cage. Being the good neighbor that I am, I rushed to fence and asked if there was anything I could do.

Her father less than calmly shouted, “What kind of sick individual would dig up a little girl’s rabbit and put it back in its cage?”

小题1:The girl was shocked because           .

A．the rabbit was killed by someone

B．the rabbit was too clean

C．the dead rabbit was cleaned and put back into the cage

D．the rabbit was asleep in the cage小题2:That day the girl ran to the cage           .

A．because her rabbit was there

B．because she had a habit of going there to see her rabbit

C．because she wanted to see her rabbit again

D．because the rabbit was dead小题3:We can infer that the rabbit           

A．was alive before the writer saw his dog dragging it

B．was already dead before the writer saw his dog dragging it

C．was in the cage playing with the dog

D．was at the fence seeking out for food before it was killed by the dog小题4:According to the story, the writer           .

A．was helpful to his neighbor

B．did a smart thing

C．was honest

D．made a mistake
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