什麼是室內給排水設施
為輸送分配可飲用的潔淨水和排出污水而在房屋內部安裝的管道及裝置系統。與為建築羣或一個城市設計的供水及下水道系統相比,室內給排水設施通常有明顯的不同。室內給排水設施體系的改進非常緩慢,從使用輸水道系統的羅馬時代一直到19世紀都幾乎沒有任何進步。最終,獨立的地下供水與下水道系統的發展消滅了開放性溝渠。現在的水管通常由鋼、銅、黃酮、塑膠或其他無毒性材料製成。一棟建築的廢物處理系統有兩個組成部分:排水系統和通風系統。排水部分由一系列管道組成,這些管道將多個設備排水口與主排水管相連,主排水管則與下水道系統相通。通風系統則由一端為氣口(通常開口在屋檐上)的管道組成,管道另一端開口於排水系統內的多個孔洞。透過在系統內提供空氣的循環,通風系統可以保障室內衞生器具的水封處不致出現虹吸反應或倒灌的壓力。亦請參閲sewage system、water pollution、water-supply system。
plumbing
System of pipes and fixtures installed in a building for the distribution of potable water and the removal of waterborne wastes. Plumbing is usually distinguished from water and sewage systems, which serve a group of buildings or a city. Improvement in plumbing systems was very slow, with virtually no progress made from the time of the Roman system of aqueducts and lead pipes until the 19th century. Eventually the development of separate, underground water and sewage systems eliminated open sewage ditches. Present-day water pipes are usually made of steel, copper, brass, plastic, or other nontoxic material. A building's waste-disposal system has two parts: the drainage system and the venting system. The drainage portion comprises pipes leading from various fixture drains to the central main, which is connected to the sewage system. The venting system consists of pipes leading from an air inlet (usually on the roof) to various points within the drainage system; by providing the circulation of air within the system, it protects the trap seals of fixtures from siphonage and back pressure. See also sewage system, water pollution, water-supply system.
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什麼是電子計算機X射線斷層成像
一種醫學影像診斷技術。用X射線對人體投射,經檢測器測定透射後的放射量,通過電子計算機處理,重建出人體斷層圖像,並作出診斷。簡史1895年倫琴發現X射線後,X射線立即被應用於臨牀診斷。為了克服影像重疊的缺點,從1914年起,先後有人採用X射線管與膠片作同步反向運動的方...
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什麼是石膏
常用清熱瀉火藥。始載於《神農本草經》。別名細理石、寒水石、軟石膏。為硫酸鹽類礦物硬石膏族石膏。石膏有軟、硬石膏兩種,中醫中的石膏為軟石膏。產地和性狀石膏多產於海灣鹽湖和內陸湖泊形成的沉積巖中,常與石灰巖、黏土、巖鹽伴生。中國的主產地是湖北、安徽...
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什麼是皮內針
用於淺刺埋針的小型針具。因針僅刺入皮內,故名。按其形狀可分為顆粒式、環式、撳釘式三種:(1)顆粒式。形似毫針,長7毫米或9毫米,針尾為金屬顆粒,常用直徑為0.22毫米或0.26毫米的金、銀或不鏽鋼絲製成。(2)環式。針尾呈環狀,長7毫米或9毫米,常用直徑0.26毫米的不鏽鋼絲製成...
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什麼是熟地黃
常用補血藥。別名熟地。始載於《本草圖經》。為玄蔘科多年生草本植物地黃Rehmanniaglutinosa根經加黃酒拌蒸至內外色黑而油潤,或直接蒸至黑潤而成(圖1)。因其色黃,質量下沉,蒸熟曬乾入藥,故名。產地和性狀中國大部地區均有生產,主產於河南孟縣、温縣、武陟、博愛等...