Weather front areas of precipitation help determine the frontal type and location. There are two different meanings used within meteorology to describe weather around a frontal zone. The term "anafront" describes boundaries which show instability, meaning air rises rapidly along and over the boundary to cause significant weather changes. A "katafront" is weaker, bringing smaller changes in temperature and moisture, as well as limited rainfall. A cold front is located at the leading edge of the temperature drop off, which in an isotherm analysis shows up as the leading edge of the isotherm gradient, and it normally lies within a sharp surface
Four Treasures of the Study Four Treasures of the Study Four Treasures of the Study, Four Jewels of the Study or Four Friends of the Study is an expression used to denote the brush, ink, paper and ink stone used in Chinese and other East Asian calligraphic traditions. The name appears to originate in the time of the Southern and Northern Dynasties (420–589 AD). Chinese culture is very fond of four word couplets, and the Four Treasures is another example: "文房四寶: 筆、墨、紙、硯," (Pinyin: "wén fáng sì bǎo: bǐ, mò, zhǐ, yàn") ""The four jewels of the study: Brush, Ink, Paper, Inkstone."" In the couplet mentioned,