high-temperature microscope

 

высокотемпературный микроскоп
Специализированный световой микроскоп, позволяющий исследовать поведение микрообъектов при температуре, существенно превышающей температуру окружающей среды.
[ ГОСТ 28489-90]

Тематики

• микроскопы

Обобщающие термины

• виды световых микроскопов

EN

• high-temperature microscope

DE

• Hochtemperatur-mikroskop

FR

• microscope de haute temperature

21. Высокотемпературный микроскоп

D. Hochtemperatur-mikroskop

E. High-temperature microscope

F. Microscope de haute temperature

Специализированный световой микроскоп, позволяющий исследовать поведение микрообъектов при температуре, существенно превышающей температуру окружающей среды

Источник: ГОСТ 28489-90: Микроскопы световые. Термины и определения оригинал документа

- centering microscope

1 adj

MECH ENG elevado, máximo

2 n

GEOL área anticiclónica f

METEO alta f, área anticiclónica f

SUBJECT AREA: Metallurgy

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The son of a distinguished engineer, Le Chatelier entered the Ecole Polytechnique in 1869: after graduating in the Faculty of Mines, he was appointed Professor at the Ecole Supérieure des Mines in 1877. After assisting Deville with the purification of bauxite in unsuccessful attempts to obtain aluminium in useful quantities, Le Chatelier's work covered a wide range of topics and he gave much attention to the driving forces of chemical reactions. Between 1879 and 1882 he studied the mechanisms of explosions in mines, and his doctorate in 1882 was concerned with the chemistry and properties of hydraulic cements. The dehydration of such materials was studied by thermal analysis and dilatometry. Accurate temperature measurement was crucial and his work on the stability of thermocouples, begun in 1886, soon established the superiority of rhodium-platinum alloys for high-temperature measurement. The most stable combination, pure platinum coupled with a 10 per cent rhodium platinum positive limb, became known as Le Chatelier couple and was in general use throughout the industrial world until c. 1922. For applications where thermocouples could not be used, Le Chatelier also developed the first practical optical pyrometer. From hydraulic cements he moved on to refractory and other ceramic materials which were also studied by thermal analysis and dilatometry. By 1888 he was systematically applying such techniques to metals and alloys. Le Chatelier, together with Osmond, Worth, Genet and Charpy, was a leading member of that group of French investigators who established the new science of physical metallurgy between 1888 and 1900. Le Chatelier was determining the recalescence points in steels in 1888 and was among the first to study intermetallic compounds in a systematic manner. To facilitate such work he introduced the inverted microscope, upon which metallographers still depend for the routine examination of polished and etched metallurgical specimens under incident light. The principle of mobile equilibrium, developed independently by Le Chatelier in 1885 and F.Braun in 1886, stated that if one parameter in an equilibrium situation changed, the equilibrium point of the system would move in a direction which tended to reduce the effect of this change. This provided a useful qualitative working tool for the experimentalists, and was soon used with great effect by Haber in his work on the synthesis of ammonia.

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SUBJECT AREA: Chemical technology, Synthetic materials, Textiles

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The introduction of one type of artificial fibre encouraged chemists to look for more. J.T.Dickson and J.R. Whinfield discovered one such fibre in 1941 when they derived polyester from terephthalic acid and ethylene glycol. Dickson, a 21-year-old Edinburgh graduate, was working under Whinfield at the Calico Printers' Association research laboratory at Broad Oak Print Works in Accrington. He was put onto fibre research: probably in April, but certainly by 5 July 1941, a murky-looking resin had been synthesized, out of which Dickson successfully drew a filament, which was named "Terylene" by its discoverers. Owing to restrictions imposed in Britain during the Second World War, this fibre was developed initially by the DuPont Company in the USA, where it was marketed under the name "Dacron". When Imperial Chemical Industries (ICI) were able to manufacture it in Britain, it acquired the brand name "Terylene" and became very popular. Under the microscope, Terylene appears identical to nylon: longitudinally, it is completely devoid of any structure and the filaments appear as glass rods with a perfectly circular cross-section. The uses of Terylene are similar to those of nylon, but it has two advantages. First, it can be heat-set by exposing the fabric to a temperature about 30°C higher than is likely to be encountered in everyday use, and therefore can be the basis for "easy-care" clothing such as drip-dry shirts. It can be blended with other fibres such as wool, and when pressed at a high temperature the creases are remarkably durable. It is also remarkably resistant to chemicals, which makes it particularly suitable for industrial purposes under conditions where other textile materials would be degraded rapidly. Dickson later worked for ICI.

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