反坡富水岩溶隧道施工的主要难题是反坡抽排水，而快速有效地排除反坡施工地段的积水，对隧道的施工组织和现场管理影响重大。
Drainage in a reverse slope is the primary problem in the construction of a tunnel in a reverse-slope stratum with abundant water.
报道了超声辐射下合成顺、反2，6-二苯基1，4-二硒富烯的简便方法，讨论了其反应机理．。
A convenient and simple method for the synthesis of ets and trans-2,6-diphenyl-1,4-diSelenafUlvenes under ultrasound conditions is described. The reaction mechanism is brieny discussed.
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