什麼是威斯丁霍斯
Westinghouse, George
美國發明家和實業家,美國用交流電傳輸電力主要是他倡導的。他的第一個重要發明是空氣制動器(1869年獲得專利),後來規定所有美國火車都必須裝有空氣制動器。後來他開始研發鐵道訊號裝置,研製成一種完整的電氣和壓縮空氣訊號系統。後來還有許多與天然氣輸送管道有關的發明。他最重要的成就是改進美國交流電的電力傳輸。1880年代美國開始發展直流電,但歐洲已發展出交流電系統。威斯丁霍斯購買了臺斯拉的交流電動機專利並請臺斯拉來改進電動機以適用於他的電網。1886年他組成西屋電氣公司。在當時他受到擁護直流電的人們的誹謗,而1893年西屋公司為芝加哥的世界哥倫比亞展覽會提供了照明電。另外他獲得以交流發電機開發尼加拉大瀑布的權利。亦請參閱electric current。
1846~1914年
Westinghouse, George
U.S. inventor and industrialist. Born in Central Bridge, N.Y., he served in the American Civil War. His first major invention was an air brake (patented 1869), which was eventually made compulsory on all American trains. He developed a railway signaling system, and later introduced many innovations in piping natural gas. His major achievement was the adoption by the U.S. of alternating current for electric power transmission. The electrical system being developed in the U.S. in the 1880s used direct current (DC), though alternating-current (AC) systems were being developed in Europe. Westinghouse purchased the patents for Nikola Tesla's AC motor and hired Tesla to improve and modify the motor for use in his power system. In 1886 he incorporated the predecessor of Westinghouse Electric Corp. He eventually prevailed over powerful opposition from advocates of DC power, and in 1893 his company was hired to light the World's Columbian Exposition at Chicago. He also obtained the rights to develop the great falls of the Niagara River with AC generators. See also electric current.
-
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,蒸熟晒乾入藥,故名。產地和性狀中國大部地區均有生產,主產於河南孟縣、溫縣、武陟、博愛等...
-
什麼是合成抗菌藥
用化學合成方法制成的抗菌藥物。主要包括磺胺類(見磺胺類藥)、喹諾酮類、呋喃類等。喹諾酮類有別於磺胺和抗生素的一類抗菌藥物,其化學結構中均有4-吡啶酮-3羧酸(見圖)。這類藥物的特點是:抗菌活性強;細菌對這類藥物和其他類抗生素之間無交叉耐藥性;對質粒介導的耐藥...
-
什麼是手部損傷
手具有複雜、精細、靈巧的功能,人們用手從事勞動。手在勞動中與外界接觸頻繁,易受損傷。手部創傷佔工業創傷的1/3強。據中國的一些統計數字,手部創傷佔全部創傷1/4強,佔四肢創傷的1/3強。手部創傷的種類可按性質分為六類。刺傷由於針、釘、刀尖或木屑等刺入手部而...
-
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...