东北杨(Populus girinensis Skv.)为落叶乔木,高12米,胸径约45厘米;树冠长卵形;树皮有沟裂;小枝圆棒状,微有短柔毛。花期4,果期5月。
张庆灵,杨冬梅,不确定广义系统的分析与综合(校庆专著),东北大学出版社,2003。
Qingling Zhang, Dongmei Yang, Analysis and Control for Uncertain Descriptor Systems, Northeastern University Press, Shenyang, 2003.
杨振成总经理1985年毕业于东北电力学院热能工程专业、高级工程师。
Yang Zhencheng, senior engineer, has been working on hydro - and thermal power technology since graduation from Northeast Dianli College majoring in thermal engineering in 1985.
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