We demonstrate the possibility of extending the well-established metrological performance of optical frequency-comb synthesizers to the mid-IR region by phase locking the pump and signal lasers of a difference-frequency source to two near-IR teeth of an optical comb. An uncertainty of 800 Hz (1.1 x 10(-11)) in the absolute frequencies of CO2 transitions near 4.2 microm has been measured by cavi...

many textbooks include semantically related words and sometimes teachers add synonyms, antonyms, etc. to the words in order to present new vocabulary items without questioning the possible effects. this study sought to investigate the effect of teaching vocabulary through synonym, semantically unrelated, and hyponym sets based on higa’s (1963) proposed continuum. a total of 120 iranian intermed...

In learning a new word by a dictionary, we first need to know a set of “basic words” which are frequently appeared in word definitions. It often happens that you cannot understand the word you looked up because there are still some words you do not understand in its definitions or explanations provided by the dictionary. You can keep looking up these new words recursively till they all can be w...

In this study, the aim was to determine academic words in Turkish teaching sets, describe numerical and rational distribution of these make a comparison between vocabulary engineering-health sciences social sciences. Vocabulary units classified as sciences, were evaluated terms their percentages own categories, most frequently used word types conceptual features analysed differences usage scien...