Under the condition of controlling liquid production per unit thickness chemical sand control can satisfy the basic needs of conventional control casing in sand production reservoir of Pan 2 block .

在控制采液强度的情况下，化学 防 砂基本能够满足盘二 块出砂油藏常规套管防砂的需要。

The permanent magnet disk-type synchronous motors used for oil-pumping unit were introduced and Vector ( controlled ) system of Permanent Magnet Synchronous Motor ( PMSM ) was presented and its control strategy and design were also analyzed . At last hardware circuit and software block were given .

介绍了 抽油机用永磁盘式同步电机，并设计了基于DSP的抽油机矢量控制系统，分析了系统的 控制策略和设计方法，并给出系统设计的硬件电路和软件 框图。

Article 21 Any unit or individual shall not damage or arbitrarily use dismantle and stop using fire control facilities and devices and shall not bury and occupy hydrant occupy fire prevention space and block fire control passageway .

第二十一条任何 单位、个人不得损坏或者擅自挪用、拆除、停用 消防设施、器材，不得埋压、圈占消火栓，不得占用消防间距，不得 堵塞消防通道。