In this paper, a conic subset Γ of R 2×R 2 is constructed, and by use of the Hilbert transform along a vector field, it is proved that the pseudo differential operator, whose symbol is the characteristic function of Γ, is unbounded on L 2(R 2).
本文构造了Ｒ２ ×Ｒ２ 中的一个锥子集Γ，以沿向量场的Ｈｉｌｂｅｒｔ 变换为工具，证明了以Γ的特征函数为象征的拟微分算子在Ｌ２（ Ｒ２） 中是无界的。
Lithodemic Creation and Emplacement Mechanism of the Zhuizishan Composite Pluton in Hebei;
河北锥子山复式深成杂岩体岩石谱系单位的建立及就位机制