阅读下面短文,回答下列问题。 要说清楚纳米科技的真正涵义不是一件易事。“纳米”只是

题型:单项选择题

问题:

阅读下面短文,回答下列问题。
要说清楚纳米科技的真正涵义不是一件易事。“纳米”只是一个长度单位,大约是10个氢原子排列起来的长度。纳米科技被广泛地定义为纳米尺度空间(如从一纳米至几百纳米)的科学技术。当科学家和工程技术人员力图在用纳米尺度来理解和控制物质的时候,就会发现许多新的现象,发明许多新的技术。用纳米颗粒粉体制成的纳米材料或具有纳米尺度晶粒的材料会显示出比一般材料更优异的性能。光刻技术的不断进步,已经使芯片的制造技术正在接近或达到100纳米,使计算机的速度越来越快,而体积越来越小。这些科技进步对工业技术发展和社会进步都具有重要意义。然而,这并不是科学家们正在探索研究的纳米科技的核心和本质,这一切不过都是传统显微加工技术的扩展和延伸而已。它们都是通过采用类似于车床、铣床、钻床等加工设备,通过“切削”材料加工成所需的产品。这种技术统称为“由上到下”或“由大到小”的加工技术。纳米科技的核心和本质在于人们创造物质的生产方式将完全不同于自石器时代以来人类用工具创造物质世界的方式,而绝不仅仅是一个长度单位所能涵盖的。纳米科技绝不意味着制造纳米尺度的产品,纳米产品可以小到分子尺度,大到汽车、飞机,只是制造的方式完全不同罢了。
要理解纳米技术的真正涵义还须从纳米技术思想的起源开始。纳米技术的灵感来自于已故美国物理学家查理·范曼的演讲,他在1959年向加州理工学院的同事们提出了一个新的想法。从石器时代开始,人类从磨尖箭头到光刻芯片的所有技术,都与一次性地削去或者融合数以亿计的原子以便把物质做成有用的形态有关。范曼质问道,为什么我们不可以从另外一个角度出发,从单个的分子甚至原子开始进行组装,以达到我们的要求呢实际上这一灵感来自于大自然从单个分子,甚至单个原子创造物质的启示。如果把人体分解成组成它的基本单元,我们获得的将是一小桶的氧、氢和氮,一小堆碳、钙和盐,微量的硫、磷、铁和镁,以及微不足道的20种或更多的其他化学元素。它们的总价值可以说是微不足道的。然而,大自然就是采用它们自己的、科学家们称之为纳米工程的方法,把这些廉价的、丰富的、无生命的单元转成具有自生成、自维持、自修复、自意识能力的生灵,可以行走、扭动、游泳,具有嗅觉和视觉,甚至可以思想和做梦,其价值无与伦比。因此,纳米技术就是向大自然学习,力图在纳米尺度精确操纵原子或分子来制造产品的技术,统称为“由底向上”或“由小到大”的加工技术。
科学家们已经或正在意识到纳米科技将给人类带来的社会变革。由于可能通过精确地控制原子或分子制造新产品,生产过程将变得非常清洁,将不产生副产品和废物。纳米技术将采用资源丰富的元素来制造完美的金刚石材料,不仅强度会比钢高几十倍,而且重量仅是钢的几十分之一。利用纳米技术,人类有可能在原子和分子尺度诊断和治愈疾病,甚至修补细胞。纳米技术将可以制造分子开关和导线,从而将导致一场计算机制造技术的革命。
(节选自张永刚《纳米科技的迷雾》)

对文中加点词语“纳米科技的核心和本质”的具体含义理解正确的一项是______。

A.传统显微加工技术的扩展和延伸

B.在纳米尺度精确地操纵原子或分子来制造产品的技术

C.制造纳米尺度的产品,可以小到分子尺度,大到汽车、飞机

D.与石器时代以来用工具创造物质世界完全不同的一种生产方式

考点:在职联考GCT(语文)工程硕士(GCT)语文95
题型:单项选择题

Directions: Read the following passage and choose the most suitable heading from A—F for each paragraph. There is one extra heading which you do not need.       

A.The results explained why time passes quickly when we are dealing with more tasks

B.Time flies when you are having fun and drags when you are bored.

C.Volunteers were told to finish three different tasks in the study.

D.There are areas of the brain having the function of estimating time.

E.Concentrating on time passing is probably a more accurate perception of reality

F.Focusing on' the duration or the color the of image makes trips speed.

小题1:

Scans have shown that patterns of activity in the brain change depending on how we focus on a task. Concentrating on time passing, as we do when bored, will trigger brain activity which will make it seem as though the clock is ticking more slowly.

小题2:

In the study, 12 volunteers watched an image while researchers monitored their brain activity using MRI scans.Volunteers were given a variety of tasks.In one they were told to concentrate simply on the duration of an image, in another they were asked to focus on the color, and in a third they were asked to concentrate on both duration and color.

小题3:

The results showed that a network of brain regions was activated when more subjects were paid attention to duration.It is thought that if the brain is busy focusing on many aspects of a task, then it has to spread its resources thinly, and pays less heed(注意) to time passing.Therefore, time passes without us really noticing it, and seems to go quickly.

小题4:

However, if the brain is not stimulated in this way, it concentrates its full energies on monitoring the passing of time.This may make time seem to drag, but in fact the researchers found that the more volunteers concentrated on the duration of the images, the more accurate were their estimates of its duration.

小题5:

Lead researcher Dr Jennifer Coull said many of the areas of the brain involved in estimating time were the same that played a key role in controlling movement, and preparing for action.She said this overlap suggests that the brain may make sense of time as intervals between movements, in much the same way as a musician marks time with his foot, or an athlete anticipates the sound of a starter's pistol(手枪).

题型:单项选择题

煮鸡蛋时不宜用以下哪种容器 [ ]

A.银制容器

B.不锈钢制容器

C.陶制容器

D.铝制容器

题型:单项选择题

毕奥呼吸常见于()

A.急性喉炎

B.呼吸中枢功能障碍

C.情绪激动

D.右心功能不全

E.左心功能不全

题型:单项选择题

要求通过while循环不断读入字符,当读入字母N时结束循环。若变量已正确定义,下列正确的程序段是( )

A) while((ch=getchar())!='N')printf("%c",ch);
B) while(ch=getchar()!='N') printf("%c",ch);
C) while(ch=getchar()=='N') printf("%c",ch);
D) while((ch=getchar()) =='N')printf('%c',ch);

题型:单项选择题

患者头痛发热,汗出恶风,鼻鸣干呕,苔白不渴,脉浮缓者。治宜选用

A.麻黄汤

B.麻杏甘石汤

C.三拗汤

D.桂枝汤

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