No.5-2 /Section B/25-26题

风潇水涵UID: 3365443

No.5-2 /Section B/25-26题  三个层次粒子的那篇

25.  According to the author, gluons are not
(A) considered to be detectable
(B) produced in nuclear reactions
(C) encountered in subnuclear energy exchanges
(D) related to the strong force
(E) found to be conditionally elementary

26.        At a higher energy level than the subnuclear level described, if such a higher level exists, it can be expected on the basis of the information in the passage that there would probably be
(A) excited nucleons
(B) elementary mesons
(C) a kind of particle without detectable mass or charge
(D) exchanges of energy on the order of millions of electron volts
(E) another set of elementary particles


最后附全文，但下面的答案解释有原文定位句
解释

答案解析如上图。
虽然当时自己也是如答案那么想的，正确选项也可以选出来。但两题这样解释是否矛盾？
黄线标注的，如果说25题排除A选项的原因是 gluons是subnuclear的，连nuclear都不能探测，gluton更加不能探测
那么按照此逻辑，26题中比subneclear能级更高的，应该更不能被探测啊，因此26的 C选项应该也可以说的通.


以上矛盾的解释，是各个题目独立，且选出最佳答案？


We can distinguish three different realms of matter, three levels on the quantum ladder. The first is the atomic realm, which includes the world of atoms, their interactions, and the structures that are formed by them, such as molecules, liquids and solids, and gases and plasmas. This realm includes all the phenomena of atomic physics, chemistry, and, in a certain sense, biology. The energy exchanges taking place in this realm are of a relatively low order. If these exchanges are below one electron volt, such as in the collisions between molecules of the air in a room, then atoms and molecules can be regarded as elementary particles. That is, they have “conditional elementarity” because they keep their identity and do not change in any collisions or in other processes at these low energy exchanges. If one goes to higher energy exchanges, say 104 electron volts, then atoms and molecules will decompose into nuclei and electrons; at this level, the latter particles must be considered as elementary. We find examples of structures and processes of this first rung of the quantum ladder on Earth, on planets, and on the surfaces of stars.

The next rung is the nuclear realm. Here the energy exchanges are much higher, on the order of millions of electron volts. As long as we are dealing with phenomena in the atomic realm, such amounts of energy are unavailable, and most nuclei are inert: they do not change. However, if one applies energies of millions of electron volts, nuclear reactions, fission and fusion, and the processes of radioactivity occur; our elementary particles then are protons, neutrons, and electrons. In addition, nuclear processes produce neutrinos, particles that have no detectable mass or charge. In the universe, energies at this level are available in the centers of stars and in star explosions. Indeed, the energy radiated by the stars is produced by nuclear reactions. The natural radioactivity we find on Earth is the long-lived remnant of the time when now-earthly matter was expelled into space by a major stellar explosion.

The third rung of the quantum ladder is the subnuclear realm. Here we are dealing with energy exchanges of many billions of electron volts. We encounter excited nucleons, new types of particles such as mesons, heavy electrons, quarks, and gluons, and also antimatter in large quantities. The gluons are the quanta, or smallest units, of the force (the strong force) that keeps the quarks together. As long as we are dealing with the atomic or nuclear realm, these new types of particles do not occur and the nucleons remain inert. But at subnuclear energy levels, the nucleons and mesons appear to be composed of quarks, so that the quarks and gluons figure as elementary particles.

crazyrobinUID: 2368627

25题
这题我觉得A并不是直接排除的
CDE可以排除最后剩下A, B
我们来看原文，

The gluons are the quanta, or smallest units, of the force (the strong force) that keeps the quarks together. As long as we are dealing with the atomic or nuclear realm, these new types of particles do not occur and the nucleons remain inert.

所以我们可以推理出在 nuclear realm中并不会产生gluons.
A并没有文章明确指出是不是detectable的，在更高级的（更多能量交换的状态）glutons能不能被探测也不知道

26题中C选项的detectable是一个不能确定的因素，所以不正确。

风潇水涵UID: 3365443

crazyrobin 发表于 2013-1-23 20:30
25题
这题我觉得A并不是直接排除的
CDE可以排除最后剩下A, B

对，应该是仅从原文推断。更高能级的particle是否可探测是不知道的。25的A就是个 无中生有的选项，无论选项中是detectable or undetectable都要舍弃