Рекомендуемая категория для самостоятельной подготовки:
Контрольная работа*
Код |
263835 |
Дата создания |
13 июня 2015 |
Страниц |
5
|
Мы сможем обработать ваш заказ (!) 25 ноября в 12:00 [мск] Файлы будут доступны для скачивания только после обработки заказа.
|
Описание
ИДЗ 1, английский язык, 3 семестр, 1 вариант. 2 курс
получен максимальный балл ...
Содержание
INDIVIDUAL TASK № 1
Variant 1
READING
Text 1
When the Russian scientist Dmitri Ivanovich Mendeleyev devised the Periodic Table in 1869, he was able to use it for much more impressive feats of deduction. He correctly predicted elements that had not yet been discovered: not just that they existed, but what they behaved like, their densities, and their melting points.
To understand how and why this information is encrypted «in the Periodic Table», we need – and not before time, to define what we mean by an element. We got a pretty good working definition from Lavoisier: if you cannot break a substance down into clearly distinct and still more fundamental constituents, it stands a good chance of qualifying as an element. Butthe problem with this definition is that it depends on how good a chemist you are, or ultimately on the capabilities of your contemporaneous chemical technology. For example, Lavoisier listed as elements «lime» and «magnesia». But neither of these qualifies: lime is calcium oxide, a compound of calcium and oxygen, and magnesia is magnesium oxide. Both calcium and magnesium were first isolated in more or less pure form by the English chemist Humphry Davy in 1808, using the technique of electrolysis – splitting compounds with electricity. The metals' avidity for oxygen is too great for them to be parted by the chemical reactions available to Lavoisier, but electricity will do the job. Davy also found the elements sodium and potassium this way in 1807. So how can we know that today's elements are not just extremely intimate compounds waiting to be split? And for that matter, if elements are meant to be fundamental and irreducible substances, how is it that gold was made from mercury in 1941, or that The Times of 12 September 1933 was able to announce a startling new discovery: Transformation of Elements'?
1. Answer the questions to the text.
1. What did the periodic Table of D. Mendeleev show and predict?
2. How did Lavoisier define an element?
3. What is the problem with this definition?
4. What methods were used to split an element?
5. What were their drawbacks?
6. What sensational news was announced in 1933?
Text 2
2. Before reading the text, say whether the statements are true or false. Check your ideas.
1. The elements in the modern table increase in atomic weight as one goes from right to left and from top to bottom.
2. The progression is defined by atomic weight not by atomic number.
3. The right way to order the elements in sequence is by atomic number, which progresses by one from each element to the next.
4. The atomic number tells us how many electrons the atoms of each element possess.
5. When atoms join together to form compounds, they do so by using their electrons as a kind of glue.
6. The sodium and chloride ions then stick together by atomic attraction.
The elements in the modern table increase in atomic weight as one goes from left to right and from top to bottom – but the weights do not advance in even steps. The progression is defined not so much by atomic weight as by atomic number. This is defined as the number of protons in the respective atomic nuclei. The atomic weight of an element – the quantity chemists could weigh with scales and balances – depends on the number of protons and neutrons, which have virtually equal masses. In light nuclei, there is a roughly equal number of each; heavier atoms have an increasing preponderance of neutrons. But the number of protons is the more fundamental quantity, since it determines the positive charge on the nucleus. Until Rutherford spread the idea that atoms contain positively charged protons, there was no concept of atomic number, let alone what it might imply.
So the right way to order the elements in sequence is by atomic number, which progresses by one from each element to the next. This number tells us how many electrons the atoms of each element possess: the number of electrons is equal to the number of protons, since the protons and electrons balance one another's charge, making the atom electrically neutral. An atom's electron count is crucial, because all chemical behaviour is determined by these particles. When atoms join together to form compounds, they do so by using their electrons as a kind of glue. There are two main ways of doing this. Some atoms like to share electrons: one of their electrons pairs up with one in another atom, making a kind of handshake. Other atoms will shed or gain electrons, becoming electrically charged ions. In the methane molecule, a carbon atom makes electronic handclasps with four hydrogen atoms. In table salt, sodium atoms donate one electron each to chlorine atoms, making the sodiums positively charged ions and the chlorines negatively charged ions (called chloride). The sodium and chloride ions then stick together by electrostatic attraction.
3. Fill in the blanks with the necessary form of the word.
According to Einstein's theory of _____1, objects gain mass when they travel at speeds close to the speed of light. In very heavy elements the electrons are ________2 into such tight orbits around the
________3 charged nuclei that they attain speeds big enough ______4 such 'relativistic' changes of mass. This shifts _____5 of electrons, and thus the element's ______6 properties, out of line with those of the elements above them in the table. The lack of strong relativistic effects in seaborgium implies that it is going to be hard ____7 and understand the way these new elements _____8.
1 RELATE
2 DRAW
3 HIGH
4 EXPERIMENT
5 ARRANGE
6 CHEMISTRY
7 PREDICTION
8 BEHAVIOUR
4. Translate the sentences from English into Russian.
1. Creating plutonium atom by atom in the Berkeley cyclotron was no way to gather a critical mass, however.
2. Enrico Fermi demonstrated a better means of synthesizing plutonium in 1942, when he and co-workers produced the first controlled nuclear chain reaction in a reactor at the University of Chicago.
3. This used natural uranium fuel, which was converted to plutonium by selfsustaining neutron emission and capture.
4. The chain reaction was held in check by rods of cadmium, which absorb neutrons, and the emitted neutrons were slowed down to fission-inducing speeds by 'moderator rods' of carbon (graphite).
5. Fermi's 'atomic pile' was just a prototype. For manufacturing bomb plutonium, a plant was built at the tiny village of Hanford in Washington State.
6. And so, drip by drip, the US war machine squeezed out its uranium-235 and plutonium, while the problem of how to build an atomic bomb was tackled by the physicists, chemists, and engineers at the Los Alamos complex in New Mexico.
7. Most major chemical companies hire chemical engineers to fill their technical positions in environmental engineering.
8. A degree in Chemical Engineering opens many doors for diverse, challenging and rewarding opportunities.
9. Chemical engineers develop processes and chemicals to make food products cheaper, safer, and with increased yields.
10. From these processes come products like orange juice, chocolate, corn sweeteners, citric acid, or vitamin E.
5. Translate the sentences from Russian into English.
1. Разрушительный эффект, который радиоактивность оказывает на ткани, не всегда плох.
2. Чтобы лечить раковые образования нужно убить нездоровые, отчаянно делящиеся клетки опухоли, но не здоровые клетки.
3. Если действие радиоизотопов ограничить пределами опухоли, то они выполнят свою разрушительную работу успешно.
4. Кобальт 60, созданный нейтронной бомбардировкой устойчивого кобальта 59, является радиоизотопом с периодом полураспада 5,3 лет, используется, чтобы лечить рак.
5. Ядро кобальта распадается до никеля 60, испуская бета частицу и два гамма-луча.
6. Гамма-лучи наносят большую часть ущерба; даже при том, что они проходят через человеческие ткани.
7. Химическое машиностроение – дисциплина, влияющая на многочисленные области технологии.
8. В общих чертах инженеры в области химической промышленности ответственны за концепцию и дизайн процессов с целью производства, преобразования и транспортировки материалов.
9. Эта деятельность начинается с экспериментов в лаборатории и сопровождается внедрением технологии в полномасштабное производство.
10. Большое количество отраслей промышленности, которые зависят от синтеза и обработки химикатов и материалов, обусловливают востребованность инженеров в области химической промышленности.
WRITING
6. Write an annotation to the text.
It is important to match mixing equipment capabilities with process requirements. While it is desirable to have an optimum design and operating conditions for every step in the process sequence, it is seldom practical to do so. For example, specialty and pharmaceutical processes require the use of multipurpose reactors. An important consideration is to understand how less than-ideal equipment will function in all stages of operation.
Documenting mixing performance data is vital to future troubleshooting. During the life of the equipment, modifications of both processes and equipment are common. For example, increased production requirements could lead to higher process concentrations and viscosity. Under such conditions, mixing may become inadequate, leading to regions of stagnation. Documented performance conditions for the original process are useful for diagnosing how the process responds to new conditions. A simple design or operational change can often meet the new challenge.
Mixing intensities vary greatly throughout a stirred vessel. While turbulent mixing can exist in the impeller region, transitional or laminar-flow conditions can exist elsewhere. Energy dissipation near the impeller is 40–50 times greater than in other regions (see Zhou and Kresta [2]). Commo n practice introduces feed to the surface of the liquid. While this avoids plugging problems and feedpipe stagnation, it places the feed in a weakly mixed region.
Computational fluid dynamics or CFD (also known as computational fluid mixing, CFM) was introduced to the chemical process industries in the late 1980s. CFD/CFM is a numerical technique for solving fluid relationships such as conservation, transport, and the Navier-Stokes equations.
Commercial CFD software enables one to predict the effects that geometry, feed location, physical properties, and operating conditions have on conditions in the vessel. Typical results predict velocity profiles, rates of energy dissipation, concentrations, and flow streamlines as they would occur in the vessel. This tool enables one to appreciate the good and bad features for each considered design.
CFD simulations are based on assumptions. Some are low risk, but some impose high risk.
Experimental validation is important particularly for nontrivial applications. Validation is advisable. Published velocity profile data can often help to validate results. At the time of this writing, CFD is weak in its ability to model large-scale turbulence and multiphase flow.
Введение
INDIVIDUAL TASK № 1
Variant 1
READING
Text 1
When the Russian scientist Dmitri Ivanovich Mendeleyev devised the Periodic Table in 1869, he was able to use it for much more impressive feats of deduction. He correctly predicted elements that had not yet been discovered: not just that they existed, but what they behaved like, their densities, and their melting points.
To understand how and why this information is encrypted «in the Periodic Table», we need – and not before time, to define what we mean by an element.
Фрагмент работы для ознакомления
3. This used natural uranium fuel, which was converted to plutonium by self-sustaining neutron emission and capture. 4. The chain reaction was held in check by rods of cadmium, which absorb neutrons, and the emitted neutrons were slowed down to fission-inducing speeds by 'moderator rods' of carbon (graphite). 5. Fermi's ‘atomic pile’ was just a prototype. For manufacturing bomb plutonium, a plant was built at the tiny village of Hanford in Washington State. 6. And so, drip by drip, the US war machine squeezed out its uranium-235 and plutonium, while the problem of how to build an atomic bomb was tackled by the physicists, chemists, and engineers at the Los Alamos complex in New Mexico. 7. Most major chemical companies hire chemical engineers to fill their technical positions in environmental engineering. 8. A degree in Chemical Engineering opens many doors for diverse, challenging and rewarding opportunities. 9. Chemical engineers develop processes and chemicals to make food products cheaper, safer, and with increased yields. 10. From these processes come products like orange juice, chocolate, corn sweeteners, citric acid, or vitamin E.Answers (translation):1. Создание атома плутония в циклотроне Беркли все же оказалось бесполезным для достижения критической массы.2. Энрико Ферми продемонстрировал лучший способ синтеза плутония в 1942 году, когда он со своими коллегами провел первую контролируемую ядерную цепную реакцию в реакторе Университета Чикаго.3. Для этого потребовалось природное урановое топливо, которое было преобразовано в плутоний путем самоподдерживающейся нейтронной эмиссии и захвата.4. Цепная реакция проводилась под контролем кадмиевых стержней, поглощающих нейтроны, а излученные нейтроны были замедлены до скоростей, вызывающих расщепление, замедляющими стержнями из углерода (графита).5. «Атомный реактор» Ферми являлся лишь прототипом. Для производства бомбового плутония был построен завод в небольшой деревне Хэнфорд в штате Вашингтон.6. – Так, капля за каплей, военная машина США вытесняла уран-235 и плутоний, в то время как физики, химики и инженеры комплекса Лос-Аламос в Нью-Мексико бились над решением проблемы создания атомной бомбы.7. Самые крупные химические компании нанимали химиков-технологов, чтобы они занимали технические должности в сфере инженерных методов и средств охраны окружающей среды.8. Степень химика-технолога открывает много дверей с разнообразными возможностями, трудными и оправдывающими себя.9. Химики-технологи работают над процессом и химическими веществами, чтобы сделать продукты питания более дешевыми и безопасными, а также повысить урожайность.10. Благодаря этим процессам появляются такие продукты, как апельсиновый сок, шоколад, сахаристое вещество из кукурузы, лимонная кислота или витамин Е.5. Translate the sentences from Russian into English. 1. Разрушительный эффект, который радиоактивность оказывает на ткани, не всегда плох. 2. Чтобы лечить раковые образования нужно убить нездоровые, отчаянно делящиеся клетки опухоли, но не здоровые клетки. 3. Если действие радиоизотопов ограничить пределами опухоли, то они выполнят свою разрушительную работу успешно. 4. Кобальт 60, созданный нейтронной бомбардировкой устойчивого кобальта 59, является радиоизотопом с периодом полураспада 5,3 лет, используется, чтобы лечить рак. 5. Ядро кобальта распадается до никеля 60, испуская бета частицу и два гамма-луча. 6. Гамма-лучи наносят большую часть ущерба; даже при том, что они проходят через человеческие ткани. 7. Химическое машиностроение – дисциплина, влияющая на многочисленные области технологии. 8. В общих чертах инженеры в области химической промышленности ответственны за концепцию и дизайн процессов с целью производства, преобразования и транспортировки материалов. 9. Эта деятельность начинается с экспериментов в лаборатории и сопровождается внедрением технологии в полномасштабное производство. 10.
Список литературы
уч. пособие, англ. яз, ТПУ
Пожалуйста, внимательно изучайте содержание и фрагменты работы. Деньги за приобретённые готовые работы по причине несоответствия данной работы вашим требованиям или её уникальности не возвращаются.
* Категория работы носит оценочный характер в соответствии с качественными и количественными параметрами предоставляемого материала. Данный материал ни целиком, ни любая из его частей не является готовым научным трудом, выпускной квалификационной работой, научным докладом или иной работой, предусмотренной государственной системой научной аттестации или необходимой для прохождения промежуточной или итоговой аттестации. Данный материал представляет собой субъективный результат обработки, структурирования и форматирования собранной его автором информации и предназначен, прежде всего, для использования в качестве источника для самостоятельной подготовки работы указанной тематики.
Другие контрольные работы
bmt: 0.00357