In Jingyuan region, the Quaternary system developed well, and zoned clearly, and there are complex genetical types.
靖远地区第四系发良良好，分带性明显，成因类型较为复杂。
The reducing in water production of tube well is a familiar problem, especially in the loose bed of the quaternary system.
管井出水量减少是常见的问题，特别是第四系松散层中的管井更为普遍。
The quaternary system piezoelectric ceramic with good properties and suitable for stationary wave ultrasonic motor is prepared.
制备了性能优良、适合于驻波超声马达的四元系压电陶瓷材料。
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