Thursday, September 15, 2022
润滑油温度升高时,则其粘度将()。A、增大B、不变C、降低...
Monday, October 31, 2022
Friday, September 16, 2022
离心泵适用于()液体。A、流量大,扬程低B、流量小,扬程高C、流量小,扬程低...
Sunday, August 13, 2023
Sunday, December 25, 2022
Saturday, December 3, 2022
氨溶解于水中,其溶液呈()性。A、酸性B、中性C、碱性...
Friday, November 11, 2022
Saturday, December 3, 2022
在串级控制回路中,包括串级内环和串级外环,其中串级控制则由串级外环的()来控制的。...
Sunday, December 25, 2022
Friday, February 3, 2023
Sunday, May 21, 2023
Saturday, December 3, 2022
Wednesday, October 26, 2022
Friday, November 24, 2023
离心泵启动时,必须关闭泵出口阀,否则会因功率消耗过大而跳闸或烧坏电机。...
Tuesday, December 12, 2023
Wednesday, May 24, 2023
离心泵机械密封泄漏率要求重质油不超过()滴/分。A、30B、20C、10D、5...
Friday, July 28, 2023
Saturday, August 19, 2023
过滤式防毒面具可在空气中氧气含量高于18%的任何环境下使用。...
Friday, February 3, 2023
当输送非粘性介质时,泵所需的汽蚀余量()。A、增大B、减小C、不变...
Wednesday, June 7, 2023