现代光学数字化处理技术的原理

随着计算机技术的高速发展,数字化处理的进程日益迅速,特别是在光学中,这种技术已经普遍地应用于全息图的记录和再现、精密测量等领域.介绍了目前国际先进的Digitalholography和白光干涉精密测量的原理.     

利用扭曲向列型液晶光阀实现对数字全息再现像质的改善

提出一种提高全息图像的清晰度的新方法.即原始图像经过微分运算和计算全息的变换后,得到它的边缘全息图,然后对该边缘全息图的对比度进行调节,再通过液晶光阀的调制作用,得到这幅调整后的全息图的再现像.这样得到的全息图的再现像比原来边缘全息图更为清晰.文中推导了黑色和白色的灰度调节函数,同时借助实验数据利用Matlab推导了光强与灰度的近似公式,并利用这些公式对图形进行了改善,实现了更为清晰的全息再现演示.     

基于光强相减与灰度值变换改善全息图再现质量

通过对数字全息图光强信息的分析,介绍了光强相减法的原理,为了进一步改善再现像的质量,提出了将光强相减和灰度值变换相结合提高再现像质量的方法.实验对比了全息图的直接再现像、用光强相减法处理后的再现像、对全息图的灰度值进行变换后用光强相减法处理的再现像.实验表明,文中提出的方法有效地削弱了中央零级像的影响,提高了全息图的再现质量.     

分数傅里叶变换全息图

提出分数付里叶变换全息图，讨论了它的性质，拍摄了假彩色编码分数付里叶变换彩虹全息图，分析了其再现条件及再现的编码颜色与再现系统的分数阶有关的特性。     

有限大小光栅的衍射分析

用稳相积分法分析了点光源经光栅光阑的衍射,得知加光阑对光栅的衍射虚像点的位置没有影响。将全息图置于有限大小平面透射光栅的衍射区域,并且满足全息图成消色散再现像条件时,白光中所有波长的色光都参与再现,形成白光消色散再现像。在有限大小平面透射光栅的衍射面上白光区域以外的区域将形成色光区域分布,将全息图置于该区域时,全息图再现像将呈现彩色。     

一种简单的白光再现全息图摄制方法

针对目前工科院校中所开设的“全息照相”实验大多只能激光再现的现状，设计了一种简单的、记录白光再现反射体全息图的光路，这种光路用于实验物理教学中，可方便地提升“全息照相”实验教学内容的层次，并且极大地调动学生的实验兴趣。     

分数傅里叶变换全息图

提出分数付里叶变换全息图,讨论了它的性质.拍摄了假彩色编码分数付里叶变换彩虹全息图,分析了其再现条件及再现的编码颜色与再现系统的分数阶有关的特性.     

全息照相实验技巧探讨

该文在全面理解全息照相“干涉记录，衍射再现”原理的基础上，分析了影响激光全息照相实验的诸因素，并对这些因素进行了深入的探讨，对提高全息图质量，提出了具体的解决方法。     

一种去除数字全息零级像的新方法(英文)

为了去除数字全息零级像,提出了用离散全息图的微分强度替代全息图本身用于数字重建的新方法.该方法基于数字图像处理技术,通过对离轴数字全息图的空间频谱分析,首先理论上证明数字全息图的强度经过微分后再重建,可有效去除零级像;然后将实验采集到的全息图在程序中先微分再重建.理论分析和数字重建结果都表明,该方法可以有效地去除数字全息零级像在重建图像中心产生的大亮斑,从而显著提高重建图像的质量,使得重建像具有良好的对比度,且不需要其他辅助设备或多次全息记录,实验操作简单,方便快捷.     

分数傅里叶变换在图像加密中的应用

基于光全息的基本概念和原理,介绍了一种任意阶傅里叶变换在光学实现的透镜模式的分数傅里叶变换数值算法,并将此算法运用到计算全息图中,给出了制作分数傅里叶变换计算全息图的过程。同时在Matlab平台上,利用计算机模拟记录和重现了全息图,通过对模拟结果的分析,表明利用分数傅里叶变换计算全息图对数字图像进行加密是可行的。     

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,     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

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…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.