什麼是西洋棋;國際象棋
通常由兩人對弈,使用一個帶格子的棋盤和特別設計的棋子。每人按照對每一種棋子着法所規定的限制去走本方的十六枚棋子,設法迫使對方的主要棋子--王--處於一種無法避免被吃掉的境地--將死。源自西元6世紀左右的亞洲地區,然而在拜占庭時期傳入歐洲後就不斷演進,在16世紀時歐洲才訂定了現今普為人接受的比賽規則。西洋棋的棋盤有顏色深淺相間的六十四個方格,共排成八個直行和八個橫排。一行行同顏色的格子在棋盤上呈交叉狀,稱為斜線。第一排放置五種不同形狀的棋子︰王、後、城堡、主教和騎士。在它們前面一排的棋子是兵。王可以向任何方向走,每着走一格。後、城堡、主教為「遠程」棋子,只要無他子阻擋,可向任何方向走,格數不限。城堡順直行或橫排走,主教走斜線;後兼有城堡和主教的威力,只要無阻擋,直、橫、斜都可走。騎士的走法奇特,走L形路線,每着先直走或橫走一格,再斜走一格,可以越子。兵的走法是隻能進,如不是吃子,則必須走直行。任何一子在敵子闖入己方領域時,可開始吃它。在比賽中每一對局者在事先規定的時間內必須走若干着棋。西洋棋比賽是按照由國際西洋棋聯合會制訂的西洋棋法進行。國際錦標賽由各管理機構主辦,並由此產生世界冠軍。多年來,俄羅斯選手是常勝軍。錦標賽以年齡分級,現在透過網路或電子信件下棋也很普遍。
chess
Checkerboard game for two players, each of whom moves 16 pieces according to fixed rules across the board and tries to capture or immobilize (checkmate) the opponent's king. The game may have originated in Asia around the 6th century, though it continued to evolve as it spread into Europe in Byzantine times; its now-standard rules first became generally accepted in Europe in the 16th century. Each opponent, designated black or white, has in his first row a king, queen, bishop, knight, and rook; in the second row are positioned the pawns. The king moves in any direction, one square at a time. The queen, rook, and bishop are “long-range” pieces that can cover all the distance across the board in any direction if not obstructed. The queen is the most powerful piece, having the moves of all the other pieces except the knight. The knight has a peculiar L-shaped movement and may leap over other pieces. The pawn moves only forward. Any piece may capture an enemy piece by landing on its square. In tournament play each player must make a given number of moves in a given period of time. International championship matches are held under the auspices of governing bodies, and world champions are declared. For several decades Russia has produced most of the top players. Tournament play is held at all age levels, and matches by mail and through the Internet are popular.
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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...