The authors show that the hyperboloid of one sheet and the hyperbolic paraboloid are ruled surfaces.作者证实:单叶双曲面和双曲抛物面是直线曲面.The mathematical model of the hyperboloid twist drill was introduced.介绍了以旋转单叶双曲面作麻花钻钻尖后刀面的数学模型.The...
欧洲的一种芬芳的象叶藜属植物,花呈黄色至绿色; 在北美归化.Eurasian aromatic oak - leaved goosefoot with many yellow - green flowers; naturalized North America.欧洲的一种藜属植物,叶具有强烈的气味; 被引入北美东部.European goosefoot with strong - scented foliage; adventive i...