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1、,微博关注：黑马PPT,联系方式：,下载地址：http:/sunny_ 天空之城红猪,01,02,03,04,东汉元兴元年（105）蔡伦改进了造纸术。蔡伦 他用树皮、麻头及敝布、鱼网等原料，经过挫、捣、抄、烘等工艺制造的纸，是现代纸的渊源。这种纸，原料容易找到，又很便宜，质量也提高了，逐渐普遍使用。为纪念蔡伦的功绩，后人把这种纸叫做“蔡侯纸”,司南是最早的磁性指向器。“司南”之称，始于战国（公元前475年公元前221年），终止于唐代（公元618年公元907年）。因为司南古义不断演化，使它与一系列的古代发明结下了不解之缘,在中国的方位文化中经历了从天文学方法定位再以磁学方法制成司南，最后由司南演
2、变成指南针的三个阶段，随之而来的是测定方位技术的不断完善。,磁勺是一种天然磁石琢成的勺形指向器，当它被发现的时候，其状取法北斗七星，名称则沿用“司南”,磁针问世后，先后用于堪舆和航海。为了使用方便，读数容易，加上磁偏角的发现，对指南针的使用技巧提出了更高的要求，方家首先将磁针与分度盘相配合，创制了新一代指南针罗盘,text.,印刷术是中国古代劳动人民的四大发明之一。雕版印刷术发明于唐朝，并在唐朝中后期普遍使用。宋仁宗时毕昇发明了活字印刷术。宋朝虽然出现活字印刷术，但并未普遍使用，而仍然是普遍使用雕版印刷术。印刷术是人类近代文明的先导，为知识的广泛传播、交流创造了条件。印刷术先后传到朝鲜、日本、
3、中亚，西亚和欧洲地区。,印刷术发明之前，文化的传播主要靠手抄的书籍。手抄费时、费事，又容易抄错、抄漏，既阻碍了文化的发展，又给文化的传播带来不应有的损失,印章和石刻给印刷术提供了直接的经验性的启示，用纸在石碑上墨拓的方法，直接为雕版印刷指明了方向。中国的印刷术经过雕版印刷和活字印刷两个阶段的发展，给人类的发展献上了一份厚礼,再见,Please add the title here,Coverage ratio,this is a sample text. insert your desired text here. Again. this is a dummy text. enter your
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