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假设光速C=3*108m/s,物理层延迟tPHY=0.15*10-5s,电信号在电缆中的传播速度为0.7C,最小帧长Lmin
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)
用高效液相色谱法分离苯、甲苯和芴,采用ODS柱(C18固定相),试回答以下问题:
(1)假设采用70%甲醇-30%水为流动相,并且上述三种化合物能够实现良好分离,出峰顺序是什么?为什么?
(2)如果将流动相由70%甲醇-30%水换成70%乙腈-30%水,上述三种物质的保留时间会如何变化?(S甲醇=3.0,S乙腈=3.2)
(3)如果苯和甲苯的保留时间分别为12.2分钟和12.8分钟,理论塔板数为3600,这两种物质之间的分离度为多少?是否满足完全分离的要求?
(4)能否采用气相色谱来分离这三种物质?气相色谱的大致出峰规律是什么?
A.会对生命和健康会产生不可逆转的或延迟性的影响
B.H2S的危险临界浓度为100ppm
C.H2S的危险临界浓度为150ppm
D.为硫化氢检测的三级报警值
假设厂商成本为C(q)=16+4q2。
(1)求出平均成本、固定成本、可变成本、平均可变成本和平均固定成本。(提示:边际成本为MC =8q。)
(2)在图上画出成本、边际成本和平均可变成本曲线。
(3)求出最小化平均成本的产出水平。
(4)当价格在哪一区间时厂商产量为正?
(5)当价格在哪一区间时厂商利润为负?
(6)当价格在哪一区间时厂商利润为正?
Suppose the same firm's cost function is C(q)=16+4q.
a. Find variable cost, fixed cost, average cost average variable cost. and average fixed cost.(Hint: Marginal cast is given by MC =8q. )
b. Show the average cost, marginal cost, and average variable cost curves on a graph.
c. Find the output that minimizes average cost.
d. At what range of prices will the firm produce a positive output?
f.At what range of prices will the firm earn a positive profit.
A.56MB/S
B.560MB/S
C.5600MB/S
D.534MB/S
A.19.98 kbit/s
B.12.97kbit/s
C.6kbit/s
D.3kbit/s