Математические действия

Addition. Сложение.	a + b = c	«a» plus «b» equals «c»; «a» plus «b» is «c»;
Subtraction. Вычитание.	a – b = c	«b» from «a» is «c»; «a» minus «b» is «c»; «a» minus «b» is equal to «c»;
Multiplication. Умножение.	a • b = c	«a» multiplied by «b» is «c»;
Division. Деление.	a : b = c	«a» divided by «b» is «c»;
Raisetopower. Возведение в степень.	a2 = b	«a» to the second power is «b»;
Evolution. Извлечение из корня.	√a =b	the square root of «a» is «b».

XXII. Прочитайте следующие формулы по английски:

F=ma;F_s=y²/2 + (q²)/gy;V= ¾πr³; Д = 113 √В.

XXIII. Напишите несколько формул, используя различные математические знаки и действия и прочитайте их по-английски.

Text a Metallurgy

Metallurgy is considered to be science and technology of metals, including the extraction of metals from ores, the preparation of metals for use, and the study of the relationship between structures and properties of metals. Metallurgical processes consist of two operations: concentration, separating a metal from the rock material; and refining, producing the metal in a pure or nearly pure state appropriate for use. Three types of processes are employed both for concentration and refining: mechanical, chemical, and electrical. In most cases metallurgists recommended that a combination of these methods was used.

One of the simplest methods of mechanical separation is gravity separation. This process is based on the difference in specific gravity between metallic minerals and rock materials with which they are mixed. When crushed ore is suspended either in water or an air blast, the heavier metallic mineral particles fall to the bottom of the processing chamber, and the lighter components are blown or washed away.

Flotation is known to be the most important present-day method of mechanical concentration. In its simplest form, flotation is a modified gravity process in which crushed ore is mixed, usually with a liquid. The metal or metallic mineral floats while the other compounds sink. In most modern flotation processes, the floating is supported by an oil or other surface-active agents. Use of the flotation process would have made possible the exploitation of many ore deposits of low concentration.

Everybody knows that such ores as magnetite have magnetic properties. They can be concentrated by means of electromagnets.

Electrostatic separation employs an electric field to separate minerals of different electrical properties by using the attraction between unlike charges and the repulsion between like charges.

Chemical separation methods are, in general, the most important from the economic point of view. In present-day practice we often observe chemical separation be used as a second stage after mechanical concentration. A greater tonnage of refined metal could be obtained by smelting than by any other process. In smelting, the ore is heated with a reducing agent and a flux to a high temperature. The reducing agent and the oxygen in a metallic oxide combine with each other, leaving pure metal; while the flux and gangue combine with each other to form a slag that is liquid at the smelting temperature and thus can be poured away from the metal. The production of pig iron in blast furnaces is an example of smelting, and the process is also used to extract copper, lead, nickel, and many other metals from their ores.

Задания к тексту A:

I. Прочитайте и переведите следующие выражения:

including the extraction of metals from ores; the study of the relationship between structures and properties of metals; the metal in a pure or nearly pure state; both for concentration and refining; the difference in specific gravity between metallic minerals and rock materials; either in water or an air blast; in its simplest form; such ores as magnetite; the attraction between unlike charges and the repulsion between like charges; the most important from the economic point of view.

II. Найдите в предыдущем упражнении английские эквиваленты следующих русских выражений:

такие руды, как магнитный железняк (магнетит); изучение отношения между структурой и свойствами металлов; либо в воде, либо в сильном потоке воздуха; самое важное с экономической точки зрения; различие в удельном весе между металлически минералами материалами горной породы; как для концентрации, так и для очистки; включая извлечение металла из руд; притяжение между разноименными зарядами и отталкивание между одинаковыми зарядами; металл в чистом или почти чистом состоянии; в своей наипростейшей форме;

III. Прочитайте предложения. Определите время и залог сказуемых. Поставьте предложения в прошедшее время:

1. In most cases metallurgists recommend that a combination of these methods was used. 2. Everybody knows that such ores as magnetite have magnetic properties. 3. In present-day practice we often observe that chemical separation is used as a second stage after mechanical concentration.

IV. Прочитайте предложения, найдите в них инфинитив, определите его функцию:

1. Electrostatic separation employs an electric field to separate minerals. 2. The flux combines with gangue to form a slag that is liquid at the smelting temperature. 3. One of the simplest methods of mechanical separation is to separate metallic minerals and rock materials by their specific gravity. 4. Flotation to be used in this process will make possible the exploitation of many ore deposits of low concentration. 5. To use the flotation process in this particular case is impossible.

V. Сделайте грамматический разбор предложения:

The reducing agent and the oxygen in a metallic oxide combine with each other, leaving pure metal; while the flux and gangue combine with each other to form a slag that is liquid at the smelting temperature and thus can be poured away from the metal.

VI. Ответьте письменно на следующие вопросы:

1. What is metallurgy?

2. What operations do metallurgical process consist of?

3. What processes are used for concentration and refining?

4. What is the simplest method of mechanical separation?

5. What is the process of gravity separation based on?

6. Is flotation the most important present-day method of mechanical concentration?

7. Use of the flotation process would have made possible the exploitation of many ore deposits of low concentration, wouldn’t it?

8. By what methods can magnetite concentrated?

9. What employs electrostatic separation?

10. What method of separation is the most important from the economic point of view?

11. What are the examples of chemical separation methods?

VII. Переведите текст А письменно.

Text B