问题 单项选择题

关于预制构件吊环的以下3种说法,试问,针对这些说法正确性的判断,下列何项正确()。

Ⅰ.应采用HPB300或更高强度的钢筋制作。当采用HRB335级钢筋时,末端可不设弯钩;

Ⅱ,宜采用HPB300级钢筋制作。考虑到该规格材料用量可能很少,采购较难,也允许采用HRB335级钢筋制作,但其容许应力和锚固均应按HPB300级钢筋采用;

Ⅲ,应采用HPB300级钢筋。在过渡期内允许使用HPB235级钢筋,但应控制截面的应力不超过50N/mm2

A.Ⅰ、Ⅱ、Ⅲ均错误

B.Ⅰ正确,Ⅱ、Ⅲ错误

C.Ⅱ正确,Ⅰ、Ⅲ错误

D.Ⅲ正确,Ⅰ、Ⅱ错误

答案

参考答案:D

解析:

依据《混规》第9.7.6条,应采用HPB300钢筋。《混规》第9.7.6条的条文说明中允许过渡期内使用HPB235级钢筋。

【命题思路】本题主要考查考生对钢筋及其选用常识的了解情况。新规范取消了HPB235级钢筋,因此对吊环设计相应作了修改,希望借本题引起注意。

【解题分析】

1.吊环应尽量采用低强度、高延性的钢筋。因此,当新规范取消了HPB235级钢筋后,规定吊环应采用HPB300级钢筋制作。也即不允许使用更高强度的钢筋。所以A错。

2.似乎B有一定的道理,但其还是违反了《混凝土结构设计规范》GB50010-2010第9.7.6条。所以B也错。

3.过渡期内,市场上仍然可能采购到HPB235级钢筋,《混凝土结构设计规范》GB50010-2010条文说明中,对此进行了规定,允许过渡期使用HPB235级钢筋。

阅读理解

A team of researchers in California has developed a way to predict what kinds of objects people are looking at by scanning what’s happening in their brains.

When you look at something, your eyes send a signal about that object to your brain. Different regions of the brain process the information your eyes send. Cells in your brain called neurons(神经元) are responsible for this processing.

  The fMRI (functional Magnetic Resonance Imaging功能性磁共振造影) brain scans could generally match electrical activity in the brain to the basic shape of a picture that someone was looking at.

  Like cells anywhere else in your body, active neurons use oxygen. Blood brings oxygen to the neurons, and the more active a neuron is, the more oxygen it will consume. The more active a region of the brain, the more active its neurons, and in turn, the more blood will travel to that region. And by using fMRI, scientists can visualize which parts of the brain receive more oxygen- rich blood--and therefore, which parts are working to process information.

  An fMRI machine is a device that scans the brain and measures changes in blood flow to the brain. The technology shows researchers how brain activity changes when a person thinks, looks at something, or carries out an activity like speaking or reading. By highlighting the areas of the brain at work when a person looks at different images, fMRI may help scientists determine specific patterns of brain activity associated with different kinds of images.

  The California researchers tested brain activity by having two volunteers view hundreds of pictures of everyday objects, like people, animals, and fruits. The scientists used an fMRI machine to record the volunteers' brain activity with each photograph they looked at. Different objects caused different regions of the volunteers' brains to light up on the scan, indicating activity. The scientists used this information to build a model to predict how the brain might respond to any image the eyes see.

In a second test, the scientists asked the volunteers to look at 120 new pictures. Like before, their brains were scanned every time they looked at a new image. This time, the scientists used their model to match the fMRI scans to the image. For example, if a scan in the second test showed the same pattern of brain activity that was strongly, related to pictures of apples in the first test, their model would have predicted the volunteers were looking at apples.

   51. What is responsible for processing the information sent by your eyes?

  A A small region of the brain.

  B The central part of the brain.

  C Neurons in the brain.

  D Oxygen-rich blood.

  52. Which of the following statements is NOT meant by the writer?

  A Cells in your brain are called neurons.

  B The more oxygen a neuron consumes, the more blood it needs.

  C fMRI helps scientists to discover which parts of the brain process information.

  D fMRI helps scientists to discover how the brain develops intelligently.

53. "Highlighting the areas of the brain at work" means

  A "marking the parts of the brain that are processing information"

  B "giving light to the parts of the brain that are processing information"

  C "putting the parts of the brain to work"

  D "stopping the parts of the brain from working"

  54. What did the researchers experiment on?

  A Animals, objects, and fruits.

  B Two volunteers.

  C fMRI machines.

  D Thousands of pictures.

55.What is the best title for the passage?

A Mind-reading Machine

B A Technological Dream

C Device that can Help You Calculate

D The Recent Development in Science and Technology

判断题