高分子成型加工实验教学仪器的改进

在高分子成型加工实验过程中如何将仪器内部的反应物及整个加工过程逼真地展现在学生面前,是一个亟待解决的问题。为此,利用棱镜和透镜做出了几种不同的光学元件,使物镜在有效的工作距离之内仍可以清晰地观察到高温环境下的目标图像,同时解决了螺杆挤出机GYZ2型探测器安装孔中物镜必须远离高温观察对象的问题。采用光纤传光,其优势在于即使光线被改变了传播方向,最终仍以合适的角度照亮目标,大大地提高了实验教学的效果。     

一种处理透镜成像问题的好方法

透镜成像问题是几何光学中的一类重要问题,它对于掌握几何光学知识,了解光学仪器的基本原理都有着重要的作用。对透镜成像问题,学生熟悉了用公式:1f=1u 1v和m=vu进行的定量计算,当物体在透镜主轴上移动,要定性地判断成像规律时,学生不易掌握。在物理教学中,笔者探索出一种图像,     

对演示光学实驗的几点意見

为了将某些只能在暗室中进行小规模观察的光学现象搬到课堂上去给较大批的学生看,应该根据不同实验的特点考虑不同的演示途径: (一) 对于能利用较强光源或较大光束的那些实验,可考虑用投射法。投射法就是将光学现象投射到屏上去以便较多的人能同时见到。这种方法在很多的场合下可以利用透镜成象的原理而完成之。由于利用了透镜可能将景象放大,同时利用了透镜也能在一定的程度上保持与光源差不多的强度而将光源重现在屏上;而光源本身往往本来就是够亮的,因而重现在屏上以后就能被多数学生所见到。某些属于几何光学或是物理光学的实验例如象差,反射得偏振光,双折射等实验都     

光学“黑匣子”问题例析

光学“黑匣子”问题指的是一类给出了光线的传播方向,要求填出光学器件的题目.做此类习题时,首先要判断出是面镜还是透镜,常用的光学器件包括:平面镜、凸面镜、凹面镜、凸透镜和凹透镜共五种,前三种属于面镜,后两种属于透镜.若题目中光线没有穿过光学器件,则应填面镜;若光线穿过光学器件,则为透镜.然后再根据三种镜或两种透镜的光学性质结合题     

“黑匣子”里面是什么？

光学“黑匣子”问题指的是一类给出了光线的传播方向，要求填出光学器件的题目。在此类习题中，首先要判断出是面镜还是透镜，常用的光器件包括：平面镜、凸面镜、凹面镜、凸透镜和凹透镜共五种，前三种属于面镜，后两种属于透镜。若题目中光线没有穿过光学器件，则应填面镜；若光线穿过光学器件，则为透镜。     

在实验室中模拟引力透镜效应以及系外行星的搜寻

根据爱因斯坦广义相对论,当光线经过大质量天体附近时会发生偏转,类似于光线经过光学透镜时发生折射现象,这种天文现象称为引力透镜效应.本文利用一个满足特定函数曲面的光学透镜来模拟引力透镜,并使用3D打印机打印出对应的透镜,模拟了爱因斯坦圆环和光源的成像,同时模拟了利用引力透镜效应搜寻系外行星.利用3D打印的透镜较好地呈现了引力透镜的主要特征,学生可以在实验室中实际模拟出引力透镜现象,可以作为一个有趣的研究性项目供学生探究.     

目标跟踪与识别实验平台建设

根据探测制导与控制领域研究的实际需求,设计了基于光学瞄准系统的目标跟踪与识别实验平台。该平台通过光学相机获得场景图像,利用嵌入式系统完成目标的检测与识别,通过上位机控制光学瞄准系统实现对目标的自动跟踪。嵌入式系统设计采用了在线编程技术,可以利用上位机自主开发目标跟踪与识别程序,并通过仿真器下载到嵌入式系统的Flash存储器中。平台整合了目标探测、跟踪与识别过程中的各个技术环节,提供了一个综合性的实验环境,可以用于目标探测与识别技术领域的科学研究和教学实验。     

利用矩阵处理几何光学中的几个成像问题

本文总结了矩阵运算在几何光学传播、成像问题中的应用,并且举了相应实例,可供使用时参考.包括光的直线传播、光经球面反射和折射、薄透镜成像,以及透镜组成像.在处理此类问题时,矩阵方法简洁规范,运用十分方便.     

薄透镜成像的几何光学规律及其傅里叶解释

透镜成像的原理和应用是一项广泛而复杂的理论和实践的内容，本文首先从几何光学的角度对光传播过程中的费马克理，薄透镜成像的规律及理论进行一般性分析，进而从波动光学的角度，运用傅里叶分析的手段对薄透镜成像的原理与规律进行更深入的剖析与解释。     

中考典型光学试题例析

1、如图1所示,AO是入射光线,OB是其经某一光学元件后的出射光线,请你用学过的光学元件在图上用作图法确定它们的位置。说明:本题重在考查是否理解光的反射定律、折射规律和透镜的性质。解本题要有较高的分析推理能力。分析:本题属改变光路的问题,光在传播过程中遇到面镜发生反射,遇到透镜发生折射都能改变光路。可选光学元件及其位置有以下8种(如图2所示)。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.