周期数对光量子阱透射谱的影响

用传输矩阵法理论,研究周期数对一维光子晶体量子阱透射谱的影响,结果表明:随着阱层或垒层周期数的增大,光子晶体量子阱的透射峰均变窄,且垒层周期数增大时透射峰变窄的速度快;垒层介质高低折射率比值越大,或垒层周期数增大,光子晶体量子阱的透射峰变窄速度越快。这些特性,对提高光子晶体光学滤波器件的品质有指导意义。     

光子晶体光纤中孤子脉冲的输入功率对脉冲演化的影响

基于耦合非线性薛定谔方程，通过数值模拟，研究了光子晶体光纤中孤子脉冲的输入功率对脉冲传输的影响。研究表明，随着孤子脉冲的输入功率的增大，孤子脉冲和信号脉冲的频移增大，群速度趋于匹配，满足一定条件时，可产生脉冲俘获现象。     

入射角对对称结构一维三元光子晶体透射谱的影响

用传输矩阵法研究对称结构一维三元光子晶体(ABC)n(CBA)n的透射谱,结果发现:随着n的增加,出现的单条透射峰越加锋锐;随着光入射角的增大,在TE偏振模情况下,窄透射峰向高频方向移动,在TM偏振模情况下向低频方向移动,而两种情况下的主禁带范围保持不变.这些传输特性为光子晶体设计和新型光学器件研制提供了有益参考.     

超短脉冲激光烧蚀SiO2材料的库仑爆炸模型理论分析

基于动理论Vlasov-Poisson方程,建立了超短脉冲激光引起的SiO2材料表面库仑爆炸烧蚀机理的理论模型,计算了在多光子吸收与雪崩2种电离机制下材料中自由电子的非平衡态分布,并在此基础上定量分析了自洽电场导致的材料表面库仑爆炸的机理及激光参数对材料表面烧蚀的影响.结果表明,在飞秒激光作用下自由电子弛豫时间不是常数...     

关于塞曼谱线的偏振性的解释

笔从原子跃迁的选择定则出发，根据角动量守恒定律推出光子的自旋角动量方向，分析了光子的自旋与偏振性的联系，较具体地解释了塞曼谱线的偏振性。     

不同介质形态对石墨结构光子晶体带隙的影响

利用平面波法研究了不同介质形态对二维石墨结构光子晶体的TE偏振模式带隙和TM偏振模式带隙的影响。研究发现,改变构成二维石墨结构光子晶体的介质柱的形态,分别选用圆柱、三角柱、矩柱、五角柱、六角柱等形态,在填充面积比相等时,石墨结构光子晶体的TE和TM两种偏振模式光子带隙都保持不变。     

椭圆偏振光在反射型磁光光子晶体中的传输

利用4×4传输矩阵法研究椭圆偏振光在反射型一维磁光光子晶体中的传输特性.设计一种反射型一维磁光光子晶体的结构模型,讨论反射光偏振态的磁场调控特性,分析外加磁场的强度和方向对反射光偏振态的影响.结果表明:改变外加磁场的强度和方向,磁光材料的介电常数发生改变;随着外加磁场强度的增大,磁光材料的相对介电常数ε_M中的ε_2的值在(0～0.009)变化,反射率逐渐增大,反射的椭圆偏振光的偏振态发生改变;随着外加磁场与光轴的夹角φ在(0°～90°)变化,反射率逐渐减小,反射的椭圆偏振光的偏振态发生改变;通过调节外加磁场的强度和方向,可以实现对反射椭圆偏振光偏振态的调控.     

光子晶体滤波器的滤波品质调制因素研究

利用传输矩阵法理论,通过数值计算模拟的方法,研究各种结构参数对光子晶体滤波器滤波品质的调制机制,结果表明:对于双正介质光子晶体,当光子晶体或光子晶体量子阱的排列周期数越大,或基元介质高折射率介质的折射率越大,光子晶体滤波器的滤波品质越高;对于单负介质光子晶体,当光子晶体介质层厚度越大,光子晶体滤波器滤波品质也越高;当双正介质光子晶体的介质换成双负介质时,光子晶体滤波器的滤波品质会降低,但随着双负介质折射率的负值增加,滤波品质会上升。光子晶体或光子晶体量子阱结构参数对滤波器品质的调制机制,为设计光子晶体滤波器以及形成其有效调制机制提供理论参考。     

二维光子晶体的电磁波理论及光子带结构

对二维光子晶体的电磁波理论及周期介质中的Bloch波解做了详细的推导；给出了光子晶体中禁带存在的理论依据；同时以三角格子晶格的二维光子晶体为例，验证了空气圆孔在电介质栅中的排列存在E偏振和H偏振的光子带隙重叠区绝对光子带隙．     

光纤电流互感器中的绕制光纤研究

为了更好的获取基于法拉第效应的光纤电流互感器中的微弱光信号提出了光纤电流互感器中的绕制光纤系统研究.系统将传感光纤绕制在直导线上,把激光通过起偏器之后耦合进入传感光纤,当在导线上加载电流时,通过功率计测量输出光信号的功率,运用法拉第效应中的微弱偏转量确定流过导线的电流大小,实现了利用旋光效应测量高压输电线电流的研究.实验中,通过比较单模光纤与多模光纤对线偏振光的消偏振影响得出,单模光纤更适合于作为本研究的传感材料;同时改变单模光纤绕制半径得出,光纤绕制半径越小线偏振光通过光纤以后消偏越严重,即双折射效应对测量精度影响越大;但受到导线直径大小及其周围磁场强度的影响,随着光纤绕制半径的增大,双折射效应对系统的影响先减小后增大,呈开口向上的抛物线形式.     

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.     

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.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

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.