Учебное пособие Издание второе, переработанное и дополненное Москва Астрель act 2005
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Part III. THE WORLD OF SUBATOMIC PARTICLES UNIT NINE GRAMMAR'. THE SUBJUNCTIVE MOOD 1 как если бы, как будто бы as though The object behaves as if it were Тело ведет себя так, как будто бы given some energy at the start. ему сообщили... для того чтобы 2. that so that in order that lest чтобы не Keep the temperature so that the Поддерживайте необходимую substance (should) not be cooled. температуру, чтобы вещество не остыло. 3. though J хотякакбыни although J Though he may (might) be busy he Как бы он ни был занят, он за-will complete the work on time. кончит работу вовремя. Sentences to be translated.
WORD AND PHRASE STUDY
• Form adverbs from the following adjectives and translate them into. Russian. pure, comparative, rapid, equal, ordinary, certain, accidental, radioactive, previous, rare, heavy, presumble READING (9A) • Read the passage attentively and be prepared to describe the phenomenon of natural radioactivity. THE DISCOVERY OF RADIOACTIVITY As is the case with so many other discoveries, the discovery ofthe phenomenon of radioactivity was purely accidental. It was discovered in 1896 by a French physicist, A.H. Becquerel (1852—1908), who was interested at that time in the phenomenon of fluorescence, i.e. the ability of certain substances to transform the ultraviolet radiation that falls on them into visible light. In one of the drawers of his desk Becquerel kept a collection of various minerals that he was going to use for his studies, but because of other pressing matters, the collection remained untouched fora considerable period of time. It happened that in the drawerthere were also several unopened boxes of photographic plates, and one day Becquerel took one of the boxes in order to photograph something or other. When he developed the plates he was disappointed to find that they were badly fogged, as if previously exposed to light. A check on other boxes showed that they were in the same poor condition, which was difficult to understand since all the boxes were sealed and the plates inside were wrapped in thick black paper. What could be the cause of this mishap? Could it have something to do with one ofthe minerals in the drawer? Being of an inquisitive mind, Becquerel investigated the situation and was able to trace the guilt to a piece of uranium ore labeled "Pitchblende from Bohemia". The reader must take into account, of course, that at that time the name "uranium" was not in vogue as it is today, and that, in fact, only very few people, even among scientists, had ever heard about that comparatively rare and not very useful chemical element. But the ability of a uranium compound to fog photographic plates through a thick cardboard box and a layer of black paper rapidly brought this obscure clement to a prominent position in physics. The existence of penetrating radiation that could pass through layers of ordinarily opaque materials as if they were made of clear glass was a recognized fact at the time of Becquerel's discovery. In fact, only a year earlier (1895) a German physicist, Wilhclm Roentgen (1845—1923), discovered what arc now known as X-rays, which can penetrate equally well through cardboard, black paper, or the human body. Although special high voltage equipment is required to produce X-rays, the radiation "discovered by Becqucrel was flowing quite steadily and without any external excitation from the piece of uranium ore resting in his desk. What could be the origin of this unusual radiation? Why was it specifically associated with the clement uranium and, as studies found, with two other heavy elements known as thorium and actinium? The early studies of the newly discovered phenomenon, which was called "radioactivity", showed that the emission of mysterious radiation was completely unaffected by physical or chemical conditions. We can stick a radioactive element into a very hot flame or drop it into liquid air without the slightest effect on the intensity ofthe mysterious radiation it emits. No matter whether we have pure metallic uranium, or its oxide which is contained in pitchblende, the radiation flows out at a rate proportional to the amount of uranium in the sample. These facts ruled out any possibility of ascribing the phenomenon of radioactivity to any kind of chemical properties of this element, and led the early investigators to the conclusion that the phenomenon of radioactivity is the intrinsic property of the atoms of these peculiar elements and that its cause must be deeply rooted in the atomic interior. • Find equivalents for the following Russian phrases. как это происходит со многими другими открытиями; чисто случайное; интересоваться; видимый свет; из-за других неотложныхдел; в течение значительного периода времени; проявить пластины; были в таком же плохом состоянии; причина этой неудачи; могло ли это быть связано с; быть популярным; проникающая радиация; светонепроницаемые материалы; на излучение совершенно не влияет; без малейшего влияния; эти факты исключали возможность; причина, должно быть, кроется; внутреннее строение атома. Re-read the passage and answer the following questions.
Be prepared to say a few words about.
Match each word in Column I with its synonym in Column II. to be the case, because of, since, to take into account, no matter, to affect, to cause, to be in vogue, to rule out II to exclude, regardless of, to influence, because, to happen, to be in fashion, on account of, to take into consideration, to bring about • Fill in the blanks with the proper word using the words in brackets. (purified, purely, purification) 1. The process of... is rather complicated. It is a ... theoretical problem. How is the material... in this case? The discovery ofthe phenomenon of radioactivity was... accidental. (excited, excitation) 2. The radiation discovered by Becquerel was flowing without any external ... from the piece of uranium ore. The highly ... atoms arc often called Rydbergatoms, aftcrthe Swedish spectroscopist Yohanncs Rydberg. Both the ion and target atom undergo electronic... during the collision. (exposed, exposure) 3. The technique is based on the use of long... to record an object's motion. The plates were badly fogged, as if previously ... to light. Several ofthe animals which were ... to radiation have died since. CLASSWORK READING (9B) • Skim the passage rapidly (2 min.) and answer the following questions.
In order to study the nature of the discovered radiation, Becquerel arranged the following very simple experiment. He placed a small amount of uranium in a deep hole made in a lead block so that only a thin beam of radiation emerged from the groove. He also placed a magnet over the block in such a way that the magnetic lines of force were running perpendicular to the direction of the emerging beam. Under these conditions one could expect three different results. If the radiation emitted by uranium were short electromagnetic waves similar to X-rays, no deflection should take place. If, on the otherhand, the radiation were fast-moving electric particles, like the cathode and anode rays in J J. Thomson's tube, the beam should be deflected to the left in the case of a negative charge and to the right in the ease of a positive one. In Becquerel's experiment all three things happened, and the original beam emerging from the hole split into three parts. The part that consisted of particles carrying a positive charge was named ос-rays and was later proved (by Rutherford) to be a stream of doubly ionized helium atoms, i.e. a stream of helium nuclei. The part consisting of negatively charged particles, which turned out to be ordinary electrons, was named fj-rays, whereas the undeflected beam formed by short-wave electromagnetic radiation similar to X-rays received the name of y-rays.
До открытия природной радиоактивности в конце XIX в. ядерные процессы оставались неизвестными. Испускание излучения ураном, открытое в 1896 г. А. Беккерелем, было первым явлением ядерного происхождения, наблюдаемым человеком. В то время были только что открыты В. Рентгеном Х-лучи, создаваемые катодными лучами втрубках, в которых наблюдаласьтакже сильная флуоресценция. А. Пуанкаре выдвинул гипотезу, что испускание X-лучей может быть связано с явлением флуоресценции. А. Беккерель, желая проверить это предположение, использовал в качестве флуоресцирующих веществ соли урана, применявшиеся в работах его отцом. Он обнаружил, что соли действительно испускают излучение, способное производить фотографическое действие через л исток бумаги и ионизировать воздух подобно рентгеновским лучам, однако испускание этого излучения наблюдается также хорошо и с нефлуоресцирующими соединениями урана. Мари Кюри предприняла изучение этого нового явления в декабре 1897: она произвела ионизационным методом точное измерение интенсивности излучения урана и показала, что аналогичное излучение испускается торием. HOMEWORK (to be done in writing) 1. Translate into Russian. 1. It is necessary that the intensity of radiation should be measured very accurately.
2. Translate into English.
UNIT TEN GRAMMAR: GERUND
 FUNCTIONS OF GERUND WORD AND PHRASE STUDY re- = again + re- + N = N re- + construction = reconstruction re- + V = V re- + model = remodel • Translate the following words into Russian: retake, retrace, reestablish, rearrange, reproduction, redirect, redistribution, recharge, recapture, redefine READING (10A) • Read the passage attentively and be prepared to say a few words about "induced" or "artificial" radioactivity. NUCLEAR FISSION Following the discovery of neutrons in 1932 due to the English physicist James Chadwick many new types of artificial nuclear transformations have been investigated. Neutrons are the ideal projectiles for nuclear bombardment because they have no electrical charge and thus suffer no repulsion in their approach to atomic nuclei. In some cases the impact of a neutron may result in the ejection of a proton or an a-particle, as in the reactions: 7NM + 0n1->6C,4 + 1H' 7Nl4 + 0n'->5B"+2H4 In some cases the incident neutron can eject another neutron without being captured itself: Cl4+ n'-^C" +2 n1 6 О О О whereas in other cases the incident neutron can be captured by the nucleus with the release of excess energy in the form ofay-quantum. The latter process, known as the radiative capture of neutrons, is of particular importance for heavy nuclear targets, since in this case the ejection of protons and a-particles is strongly hindered by the "outgoing" potential barrier surrounding the nucleus. I fit were not for the radiative capture ofthe neutron no heavier isotope of the bombarded clement would be formed. Sometimes these isotopes are stable so that no further nuclear transformation takes place: r|6+ п'-^я017 + у Hon1 whereas in some other cases the radiative capture of a neutron leads to a (i-emission: 47Ag'w + on'->47Ag"u + Y 47Ag4°->48Cd» + e- which is necessary to re-establish the proper neutron-to-proton ratio. In the year 1939, a German radio-chemist, Otto Hahn, with his coworker, Frits Strassman, studied the effect of the neutron bombardment of uranium atoms, expecting to observe the formation of uranium isotopes with atomic weights higher than that of ordinary uranium, i.e., 238. To his great surprise Hahn found that the sample of uranium bombarded by neutrons contained radioactive atoms of a much lighter clement, barium. The mystery of this discovery was soon cleared up by two German physicists, Lisc Meitner and Otto Frisch, who suggested that in Hahn and Strassman's experiments the nuclei of U218 were split by incident neutrons into two nearly equal parts: П238 +ni_4Ba144+, ftKr94 32 о 56 36 Since the barium and krypton atoms produced in this process possessed excess neutrons, as compared with ordinary stable atoms of the same atomic weight (60Nd144 and 40Zr94), these so-called fission products emitted negative electrons, makingthem strongly radioactive. Frishand Meitner's interpretation of Hahn and Strassman's experimental finding as the splitting ofthe uranium nucleus into two nearly equal parts opened new vistas in the field of nuclear physics. Instead ofjust "chipping off' small pieces ofthe bombarded nucleus, as was the case in all previous experiments, here was a real breakup ofthe central body of the atom, the fission of a large droplet of the nuclearfluid into two half-size droplets. Instead ofjust the few million electron-volts of energy observed in previous experiments on artificial nucleartransformations, uranium fission liberates 200 MeV per atom. The detailed theoretical studies ofthe process of nuclear fission were carried out by Niels Bohr and John Wheeler and published in the September 1939 issue of the Physical Review. This was the first and last comprehensive article on the theory of nuclear fission that appeared as "open literature" before the "security curtain" was drawn tight on that subject. According to Bohr and Wheeler, the fission of heavy nuclei resulting from the impact of a neutron is a resolution of a conflict between the opposing tendencies of nuclear (attractive) and Coulomb (repulsive) forces acting in the atomic nucleus. • Find English equivalents for the following Russian phrases. не испытывают никакой отталкивающей силы; на две почти равных части; вслед за открытием; загадка этого открытия была вскоре разрешена; как это происходило во всех предыдущих экспериментах; может привести к; идеальные частицы; радиационный захват; по сравнению с обычными устойчивыми атомами; испусканию протонов и альфа-частиц серьезно мешает; последний процесс особенно важен; эти так называемые продукты деления; никакого дальнейшего ядерного превращения не происходит; правильное отношение числа нейтронов к числу протонов; избыточные нейтроны; избыточная энергия; налетающий нейтрон • Read the passage again and answer the following questions.
• Be prepared to say a few words about:
• Choose the proper word to fill up the blanks in the sentences below. (capture, incident, collisions, fission, releases, results in)
• Translate into English making use of according to.
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