【单选题】What was one of the things Pacific Gas and Electric did in the 1989 San Francisco eqrthquake?
A.
Restoring service to its 1.4 million customers within 48 hours.
B.
Writing personal letters of assurance to its 106000 shareholders.
C.
Setting up a hotline for the employees as well as customers.
D.
Running ads in daily newspapers and weekly magazines for as long as 60 days.
【多选题】下列关于活性炭吸附试验和设计描述正确的是:
A.
吸附容量试验中,单位重量的活性炭在平衡时所吸附的溶质量可表示为 ,式中:m为投入的活性炭质量;v为试验水样容积;c。为水样初始溶质 Ⅱl 浓度;C。为吸附平衡时溶质浓度;q。为吸附容量
C.
吸附动力学试验中,溶质浓度变化速率可表示为: ,式中:ka为吸附速率常数;t为时间;C为不同时间t的水样中的溶质浓度;Co为水样初始溶质浓度;C。为吸附平衡时溶质浓度
D.
活性炭吸附滤床设计中 关系成立,式中:V为吸附滤速;h为炭层厚度;R为炭床容积;Q为设计流量
【单选题】某研究探讨氧疗对缓解妇科腹腔镜术后患者肩部疼痛的影响。研究方法是将腹腔镜术后第1天肩痛的患者随机分为试验组、对照组;对照组接受术后常规护理,试验组除常规护理外,8:00和16:00分别给予2h的吸氧。患者疼痛情况定时评分,比较两组患者肩痛情况的缓解程度。此研究属于的设计类型是()。
【判断题】奇函数加上直流后,傅氏级数中仍含有正弦分量
【判断题】奇函数加上直流后,傅氏级数中仍含有正弦分量。
【判断题】奇函数加上直流后,傅氏级数中仍含有正弦分量。
【单选题】What was one of the things Pacific Gas and Electric did in the 1989 San Francisco earthquake?
A.
Restoring service to its 1.4 million customers within 48 hours.
B.
Writing personal letters of assurance to its 106,000 shareholders.
C.
Setting up a hotline for the employees as well as customers.
D.
Running ads in daily newspapers and weekly magazines for as long as 60 days.