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文献获取国学大讲堂 徐霞客游记导读
它生动,准确,详细地记录了祖国丰富的自然资源和地理景观,为历史地理学的研究提供了极其珍贵的重要资料,具有很高的科学价值和社会效益,开创了我国地理学史上实地考察并系统描述自然的先河.本书为"国学大讲堂"丛书之一,对《徐霞客游记》作了详细的解读...
贸易对食料供给的影响
唐宋元三朝,均属于中国历史上的"开放"时代,虽然受制于军力较弱和版图不广等原因,宋的"开放"程度不如唐,元,但宋人的经济贸易能力完全能与其比肩而立.\n得益于运河和...
俞为洁
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茶叶包装盒(楮河毛尖)
1.本外观设计产品的名称:茶叶包装盒(楮河毛尖);2.本外观设计产品的用途:茶叶产品的包装;3.本外观设计的设计要点:图案;4.最能表明设计要点的图片是套件2主视图;5.套...
Thrust transmission
PROBLEM TO BE SOLVED: To transmit a thrust when a pipe is laid by driving forward a pipe such as a vinyl chloride pipe and facilitate an arranging work for propulsion and a recovery work of wires after the propulsion.
Continual melting metal plated device, bearing for continual melting metal plated device, and roll null for continual melting metal ...
PROBLEM TO BE SOLVED: To reduce friction coefficient in a sliding part in a hot dip metal plating bath and to improve its slidability by composing at le...
Continual melting metal plated device, bearing for continual melting metal plated device, and roll null for continual melting metal ...
PROBLEM TO BE SOLVED: To reduce friction coefficient in a sliding part in a hot dip metal plating bath and to improve its slidability by composing at le...
