Подберите русские эквиваленты к следующим словам и словосочетаниям
| A | B |
| 1. steam – engine 2. to consist of 3. hollow 4. to revolve 5. a pair of 6. at the ends 7. to supply 8. a serious difficulty 9. axis 10. machinery 11. inventor 12. piston 13. step forward 14. pressure 15. one of the reasons 16. to go down 17. many more use | a. гораздо больше применений; b. снабжать, обеспечивать c. ось d. вращаться e. состоять из f. изобретатель g. шаг вперед h. пара (чего-либо) i. механизмы j. опускать(ся) k. давление l. полый(пустой) m. на концах n. одна из причин o. паровой двигатель p. поршень q. серьезное затруднение |
3. Определите, какой частью речи является каждое слово из колонки A, и дайте его значение, взяв за основу значение слова с тем же корнем из колонки B:
| A | B | ||
| development | ??? | develop v. | развивать |
| use | ??? | use v. | использовать |
| inventor | ??? | invent v. | изобретать |
| production | ??? | produce v. | производить |
| social | ??? | society n. | общество |
| valuable | ??? | value n. | ценность |
| distant | ??? | distance n. | расстояние |
Подберите антонимы к данным словам.
| A | B |
| difficulty to lift strong to end first good active | to go down passive last to begin easiness weak bad |
Определите, какой частью речи являются следующие слова.
Переведите их:
Brilliant, continuous, merely, explosion, dominate, materialize, development, invention, inventor, improvement.
6. Переведите, обращая внимание на местоимения some, any, no, every и их производные:
1. Have you any interesting books on this problem?
2. Here are some letters for you.
3. Any student can make this simple experiment.
4. Somebody works in the laboratory every evening.
5. Nobody uses this instrument.
6. She never says anything about her Institute.
7. No laboratory assistant works in this laboratory in the evening.
8. Somebody gave me this book yesterday.
9. Is there anybody in this room?
10. Every student of our group can do this work without any effort.
11. No information was received from the article.
UNIT 5
Ultrasonic Welding
When bonding material through ultrasonic welding, the energy required comes in the form of mechanical vibrations. The welding tool (sonotrode) couples to the part to be welded and moves it in longitudinal direction. The part to be welded on remains static. Now the parts to be bonded are simultaneously pressed together. The simultaneous action of static and dynamic forces causes a fusion of the parts without having to use additional material. This procedure is used on an industrial scale for linking both plastics and metals (figure).
Figure: Differences in the process for welding plastics and metals with ultrasonics
1. Anvil
2. Parts to be welded
3. Sonotrode
4. Ultrasonic oscillation
Ultrasonic welding of plastics is a state-of-the-art technology that has been in use for many years. When welding thermoplastics, the thermal rise in the bonding area is produced by the absorption of mechanical vibrations, the reflection of the vibrations in the connecting area, and the friction of the surfaces of the parts. The vibrations are introduced vertically. In the contraction area, frictional heat is produced so that material plasticizes locally, forging an insoluble connection between both parts within a very short period of time.
The prerequisite is that both working pieces have a near equivalent melting point. The joint quality is very uniform because the energy transfer and the released internal heat remains constant and is limited to the joining area. In order to obtain an optimum result, the joining areas are prepared to make them suitable for ultrasonic bonding. Besides plastics welding, ultrasonics can also be used to rivet working parts or embed metal parts into plastic.
Whereas in plastic welding, high-frequency vertical vibrations (20 to 70kHz) are used to increase the temperature and plastify the material, the joining of metals is an entirely different process. Unlike in other processes, the parts to be welded are not heated to melting point, but are connected by applying pressure and high-frequency mechanical vibrations.
In contrast to plastics welding, the mechanical vibrations used during ultrasonic metal welding are introduced horizontally.