兰州大学物理科学与技术学院期末考试

光学试题

（满分100分，时间120分钟）

班级_________ 姓名__________ 学号__________

一、简答题（每小题10分，共40分）

1. 写成矩形函数，圆域函数、sinc函数、delta函数、高斯函数的定义，并说明它们对应光学当中的什么物理量。

2. 雨后彩虹、CD光盘、孔雀羽毛、蝴蝶翅膀当中的彩色各是运用什么光学原理形成的彩色？

3. 什么是数字全息？数字全息与光学全息有什么相同之处和不同之处？简述数字全息在工程方面的应用。

4. 你了解的现代光学的前沿进展是有哪些？举两个例子说明其在光学工程或者是现代物理学前沿方面的应用。

二、计算题（每小题20分，共60分）

1. 如图所示，虚物会聚于P点，现在图示位置加上一厚度均匀的透明玻璃片，玻璃片的折射率为n=1.5，此时光线会聚于P’点。求玻璃片的厚度t。

2. 一光栅每毫米有250条刻线，光栅的长度是4mm，已知光栅的透光部分是不透光部分的2倍。现有波长为560nm和560.6nm的两种单色光垂直入射到光栅上，衍射光通过一个透镜来会聚，透镜的焦距为1m，求

（1）中央峰内主极大的数目；

（2）第1级衍射光谱中两种波长的光分开的距离；

（3）能否在第二级光谱中分辨出两种波长的光？

3. 强度为I0的光照射到如图所示的衍射屏，求通过衍射屏的光是光这个角度一般是入射光矢量与光轴夹角，用来分解o光，e光的。不清楚你的问题是什么角。非相干照明条件下薄透镜成像系统的截止频率是相干照明条件下系统的2倍， 即非相干照明条件下能通过薄透镜到达像面的频率成分更高。试证明上述结论。

英语能力测试题（共40分）

科技文献翻译（满分40分）

Seeing inside the living cells

Texting has long been bemoaned (哀叹）as the downfall of the written word,””penmanship for illiter,”as one critic called it. To which the proper response is LOL.

Texting properly isn't writing at all. It's a “spoken” language that is getting richer and more complex by the year.

First,some historical perspective. Writing was only invented 5,500 years ago. whereas Ianguage probably traces back at least 80.000 years. Thus talking came first; writing is just a craft that came along later. As such, the first writing was based on the way people talk，with short sentences.

However, while talking is largely subconscious and rapid, writing is deliberate and slow, Over time,writers took advantage of this and started cratting long-winded sentences such as this one:The whole engagement lasted above 12 hours, till the gradual retreat of the Per trsians was changed into a disorderly flight, of which the shameful example was given by the principal leaders and??”

No one talks like that casually — or should. But it is natural to desire to do so for special occasions. In the old days, we didn’t much write like talking because there was no mechanism to reproduce the speed of conversation. But texting and instant messaging do — and a revolution has begun. It involves the crude mechanics of writing, but in its economy, spontaneity and even vulgaritv. texting is actually a new kind of talking, with its own kind of grammar and conventions.

Take LOL. It doesn’t actually mean “laughing out loud” in a literal sense anymore. LOL has evolved into something much subtler and sophisticated and is used even when nothing is remotely amusing. Jocelyn texts “Where have you been?” and Annabelle texts back ，LOL at the library studying for two hours.” LOL signals basic empath)’（同感)between tcxters. easing tension and creating a sense of equality. Instead of having a literal meaning, it docs something - conveying an attitude — just like the -cd ending conveys past tense rather than “meaning.，anything. LOL. of all things, is grammar.

Of course no one thinks about that consciously. But then most of communication operates without being noticed. Over time, the meaning of a word or an expression drifts meat used to mean any kind of food, silly used to mean, believe it or not，blessed.

Civilization, then，is fine 一 people banging away on their smartphones are fluently using a code separate from the one they use in actual writing, and there is no evidence that texting is ruining composition skills. Worldwide people speak differently from the way they write, and texting -quick, casual and only intended to be read once — is actually a way of talking with your fingers.

it's possible to admire oprah winfrey and still wish Harvard hadn't awarded her an honorary doctor of law degree and the commencement(毕业典礼)speaker spot at yesterday's graduation.There's no question Oprah's achievements place her in the temple of American success stories. Talent,charm,and an exceptional work ethic have rarely hurled anyone of world's most successful entertainment icons and the first African-American female billionaire.

Honorary degrees are often conferred on non-academic leaders in the arts,business,and politics.Harvard's list in recent years has included Kofi fi Annan,Bill Gates,Meryl Streep,and David Souter.But Oprah's list in recent years has included Kofi Annan,Bill Gates,Mery1 Streep,and david souter.But Oprah's particular brand of celebrity is not a good fit for the values of a university whose motto（座右铭）,Veritas,means truth.Oprah's passionate advocacy extends,unfortunately,to a hearty embrace of fake science.Most notoriously,Oprah's validation of jenny McCarthy's claim that vaccines cause autism(自闭症)has no doubt contributed to much harm through the foolish avoidance of vaccines.

Famous people arc entitled to a few failings, like the rest of us. and the choice of commencement speakers often reflects a balance of insututional pnonties and aspirations. Judging from our conversations with many students. Oprah was a widely popular choice.

But this vote of confidence in Oprah sends a troubling message at precisely the time when American univereities need to do more to advance the cause of reason. As former Dean of Harvard College. Harry Lewis, noted in a blog post about his objections. “It seems vcrv odd for Harvard to honor such a high profile popularizer of the irrational?? at a time when political and religious nonsense so jeopardize the rule of reason in this allegedly enlightened democracy and around the world.”

As America’s oldest and most visible university. Harvard has a spccial opportunity to convey its respcct for science not only through its research and teaching programs but also in its public affirmation of evidence-based inquiry.

Unfortunately，many American universities seem awfully busy protecting their brand name and not nearly busy enough protecting the pursuit of knowledge. A recent article in The Harvard Crimson noted the shocking growth of Harvard's public relations arm in the last five years and it questioned whether a focus on risk management and avoiding controversywas really the best outward-looking face of this great institution.

As American research universities begin to resemble profit centers and entertainment complexes, it’s easy to lose sight of their primary mission; to produce and spread knowledge.This mission depends on traditions of rational discourse and vigorous defense of the scientific method.Oprah Winfrey’s honoray doctorate was a step in the wrong direction.

兰州大学物理科学与技术学院期末考试

光学试题【答题卡】

（满分100分，时间120分钟）