专项练习:2021年考研英语基础模拟题(四十二)
发布时间:2020-10-26
2021年考研初试备考还有最后的近两个月时间,相信大家也都在紧张的复习当中。在复习时,多做练习题可以让我们更加了解考试内容。下面,51题库考试学习网为大家带来考研初试的一些模拟试题,正在备考的小伙伴赶紧练起来吧。
Part C
Directions:
Read the following text carefully and then
translate the underlined segments into Chinese. Your translation should be
written clearly on ANSWER SHEET 2. (10 points)
Relativity theory has had a profound
influence on our picture of matter by forcing us to modify our concept of a
particle in an essential way. (47)In classical physics, the mass of an object
had always been associated with an indestructible material substance, with some “stuff” of which all things were thought to be
made. Relativity theory showed that mass has nothing to do with any substance,
but is a form energy. Energy, however, is a dynamic quantity associated with
activity, or with processes.(48)The fact that the mass of a particle is
equivalent to a certain of energy means that the particle can no longer be seen
as a static object, but has to be conceived as a dynamic pattern, a process
involving the energy which manifest itself as the particle’s mass.
(49)This new view of particles was
initiated by Dirac when he formulated a relativistic equation describing the
behavior of electrons. Dirac’s
theory was not only extremely successful in accounting for the fine details of
atomic structure, but also revealed a fundamental symmetry between matter and
anti-matter. It predicted the existence of an anti-matter with the same mass as
the electron but with an opposite charge. This positively charged particle, now
called the positron, was indeed discovered two years after Dirac had predicted
it. The symmetry between matter and anti-matter implies that for every particle
there exists an antiparticles with equal mass and opposite charge. Pairs of
particles and antiparticles can be created if enough energy is available and
can be made to turn into pure energy in the reverse process of
destruction.(50)These processes of particle creation and destruction had been
predicted from Dirac’s
theory before they were actually discovered in nature, and since then they have
been observed millions of times.
The creation of material particles from
pure energy is certainly the most spectacular effect of relativity theory, and
it can only be understood in terms of the view of particles outlined
above.(51)Before relativistic particle physics, the constituents of matter had
always been considered as being either elementary units which were
indestructible and unchangeable, or as composite objects which could be broken
up into their constituent parts; and the basic question was whether one could
divide matter again and again, or whether one would finally arrive at some
smallest indivisible units.
参考答案:
47.在古典物理中,某一物体的质量总是与一种不可毁灭的物质相关联。这是一种构成一切物质的“东西”。
48.某一粒子的质量相当于一定的能量,这一事实意味着该粒子不再被看作是一个静态的物体,而应该被看成是一种动态的形式,一种与能量表现为粒子质量相关的过程。
49.这一新的粒子观是由迪拉克首创的,他列出了描述电子运动行为的相对论方程。
50.粒子生成和毁灭的过程在真正被发现之前,迪拉克的理论已经对它们作出了预测,从那时起人们对此做过数百万次的观测。
51.在相对论粒子物理学诞生之前,人们一直以为物质的构成成分要么是不可毁灭和不可改变的基本单位,要么是可以分解为其构成部分的合成物。
以上就是51题库考试学习网为大家带来的全部内容,希望能给大家一些帮助。51题库考试学习网提醒:目前2021年考研大纲已经公布,小伙伴们在复习时要注意以大纲为准哦。另外,小伙伴们如果还有其他关于考研信息的疑问,也可以留言咨询哦。
下面小编为大家准备了 研究生入学 的相关考题,供大家学习参考。
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