什么是德克萨斯
美国中南部一州。面积691,030平方公里,就面积和人口来说都是美国的第二大州。首府奥斯汀。全州以平原和丘陵为主,依次为墨西哥湾畔肥沃的沿海平原,中部大平原的草场,一直到西北突出部干旱的高原。早在37,000年前,德克萨斯西部就有印第安人先驱的足迹。其中一些部落以後形成了卡多人的松散联盟。当西班牙人在1528年到来时,印第安人,包括阿帕契人居住於此。1685年法国人最早尝试在此定居,声称此地为路易斯安那的一部分。美国通过1803年的路易斯安那购地案从法国手中得到此地,但1819年又出让给了西班牙。1821年墨西哥独立使这里成为墨西哥的一部分。1836年德克萨斯人宣布从墨西哥独立,成立德克萨斯共和国。历经十年挣扎的共和国最终在1845年成为美国的第28个州。1848年的墨西哥战争後,其与墨西哥之间的边界才算正式画定。在美国南北战争中,它於1861年退出联邦,然後於1870年重新被接纳加入。南北战争後,铁路的建设以及海运的增加加快了经济成长,1901年石油的发现更是给该州带来了根本变化。至今德克萨斯的石油和天然气生产以及提炼石油的能力依然在美国全国领先,电子、航天以及其他高科技的制造业也越益占有重要地位。棉花生产、肉牛和绵羊的饲养量居全国首位。人口约19,439,000(1997)。
Texas
State (pop., 1997 est.: 19,439,000), southwestern U.S. Occupying 266,807 sq mi (691,030 sq km), it is the second-largest state in both area and population. Its capital is Austin. Plains and hills make up the terrain, which ranges from the fertile prairie of the Coastal Plains on the Gulf of Mexico through the central Great Plains grasslands to the arid High Plains of the Panhandle. The forerunners of West Texas Indians inhabited the area as much as 37,000 years ago. Some of the tribes later formed the Caddo confederacy. Indians, including Apaches, lived in the region when the Spanish arrived in 1528. The first settlement was attempted in 1685 by the French, who claimed the region as part of louisiana. In 1803 the U.S. acquired the French claim in the Louisiana Purchase, but relinquished it to Spain by treaty in 1819. It became part of Mexico at Mexican independence in 1821. In 1836 Texans declared independence from Mexico as the Republic of Texas (see Stephen Austin, Sam Houston). After a 10-year struggle to remain independent, Texas became the 28th U.S. state in 1845. Its boundary with Mexico was fixed after the Mexican War (1848). In the American Civil War, it seceded from the Union (1861) and was readmitted in 1870. After the war, railroad building and increased shipping helped expand the economy, and the discovery of oil in 1901 transformed it. While Texas still leads all other states in oil and natural-gas production and in petroleum-refining capacity, its manufacture of electronics, aerospace components, and other high-technology items is increasingly important. It is also the U.S.'s leading cotton, beef-cattle and sheep producer.
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什么是浸润
组织内侵入了异常的细胞或出现了正常情况下不应出现的机体细胞,以及某些病变组织向周围扩展的现象。在细胞内或间质中出现异常的物质、或原有的某些物质的堆积过多也称为浸润。有的变性或沉积也称为浸润。浸润大多为病理性的,但有时是为了治疗目的而人为的。它们...
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什么是细菌性感染
细菌引起的感染。包括医院外感染和医院内感染。引起医院外感染最常见的细菌为革兰氏阳性菌如金黄色葡萄球菌、肺炎链球菌、化脓性链球菌和革兰氏阴性的大肠杆菌、流感嗜血杆菌等;引起医院内感染的则多为有耐药性的金黄色葡萄球菌、表皮葡萄球菌、肠球菌、克雷伯...
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什么是肾性骨营养不良
由慢性肾功能衰竭导致的骨代谢病,表现为钙磷代谢障碍、酸碱平衡失调、骨骼畸形,并可引起继发性甲状旁腺功能亢进。肾性佝偻病常由慢性肾小球肾炎、慢性肾盂肾炎、肾结核、肾肿瘤、肾结石或先天性肾盂积水引起。由于肾小球遭到破坏,间质纤维化、肾小管萎缩、尿浓缩...
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什么是三叉神经痛
面部三叉神经感觉支分布区出现的短暂发作性疼痛。多发病于中年以上,40岁以上占70~80%,而70岁以上又逐渐减少。患者中女性多于男性,两者之比为3:2。多为一侧性,双侧受罹者在5%以下。以三叉神经第二支(上颌支)受侵犯者最常见,其次为第三支(下颌支),第二、三支同时患病者亦常见...