问题 单项选择题

在重复性试验中,对峰面积测量值的RSD的要求是()

A.0.3~0.7

B.>1.5

C.≤2.0%

D.≤0.1%

E.0.95~1.05

答案

参考答案:C

解析:本组题考查高效液相色谱法系统适用性试验的指标要求。色谱柱的理论板数(n)应符合规定;定量分析时,对分离度(R)的要求应大于1.5;在童复性试验中,取各品种项下的对照品溶液,连犊进样5次,除另有规定外,其峰面积测量值的相对标准偏差(RSD)应不大于2.0%;用峰高法定量时,拖尾因子(T)应在0.95~1.05。该内容除以配伍选择题出现外,也常以多项选择题出现。建议考生熟悉色谱法(如薄层色谱法、气相色谱法和高效液相色谱法)系统适用性试验指标要求及含义。

解答题
单项选择题

Weak dollar or no, $ 46,000-the price for a single year of undergraduate instruction amid the red brick of Harvard Yard-is (1) But nowadays cost is (2) barrier to entry at many of America’s best universities. Formidable financial-assistance policies have (3) fees or slashed them deeply for needy students. And last month Harvard announced a new plan designed to (4) the sticker-shock for undergraduates from middle and even upper-income families too.

Since then, other rich American universities have unveiled (5) initiatives. Yale, Harvard’s bitterest (6) , revealed its plans on January 14th. Students whose families make (7) than $60,000 a year will pay nothing at all. Families earning up to $ 200,000 a year will have to pay an average of 10% of their incomes. The university will (8) its financial- assistance budget by 43%, to over $ 80m.

Harvard will have a similar arrangement for families making up to $180,000. That makes the price of going to Harvard or Yale (9) to attending a state-run university for middle-and upper-income students. The universities will also not require any student to take out (10) to pay for their (11) , a policy introduced by Princeton in 2001 and by the University of Pennsylvania just after Harvard’s (12) . No applicant who gains admission, officials say, should feel (13) to go elsewhere because he or she can’t afford the fees.

None of that is quite as altruistic as it sounds. Harvard and Yale are, after all, now likely to lure more students away from previously (14) options, particularly state-run universities, (15) their already impressive admissions figures and reputations.

The schemes also provide a (16) for structuring university fees in which high prices for rich students help offset modest prices for poorer ones and families are less (17) on federal grants and government-backed loans.

Less wealthy private colleges whose fees are high will not be able to (18) Harvard or Yale easily. But America’s state-run universities, which have traditionally kept their fees low and stable, might well try a differentiated (19) scheme as they raise cash to compete academically with their private (20) . Indeed, the University of California system has already started to implement a sliding-fee scale.

10()

A. part-time job

B. work

C. loans

D. savings