基于群论的晶格扰动介质纳米孔阵列多重Fano共振机理及演变

基于全介质超构材料独特的电磁属性,提出了一种晶格扰动介质纳米孔阵列超构表面来激发近红外区域的多重Fano共振.结合群论深入探究了该超构表面在其原胞为方形晶格构型与方形晶格对称性被破坏两情况下多重Fano共振的形成机理及演变规律.研究表明,在方形晶格超构表面中,外部辐射连续体分别与由正入射平面波直接激发的双重简并模式共振干涉形成双重Fano共振,且该共振与原胞中是否含孔及孔的形状无关,在晶格扰动超构表面中,原本不耦合的非简并模式由正入射平面波激发出来并与外部辐射连续体干涉形成Q值更高的三重Fano共振.进一步探讨了正入射平面波的xy极化方向对上述五重Fano共振的影响,结果表明,双重简并模式Fano共振偏振无关,三重非简并模式Fano共振偏振依赖.本文将为利用方形晶格构型的超构表面实现多重Fano共振的激发及演变提供有效的理论参考.     

为什么要引入溶剂的渗透因子

阐明了引入溶剂渗透因子的必要性,较详细地介绍了两种渗透因子及它们间的关系。     

磁各向异性色散介质散射的Pad啨时域有限差分方法分析

根据矩阵Pad啨逼近理论,把磁化色散介质的相对磁导率张量表示成以jω为自变量的矩阵函数形式,用/t代替jω后过渡到时域,再引入离散时域移位算子代替时间微分算子.进而导出磁化色散介质中的磁感应强度B和磁场强度H在离散时域的色散关系,并将其具体应用于旋磁介质,得到了这种磁化色散介质的Pad啨时域有限差分方法的递推表达式.作为验证,用这种方法计算了磁化铁氧体球的后向雷达散射截面,所得结果与文献结果一致.理论推导及算例表明,该方法是正确和有效的.     

合肥光源高亮度模式Lattice设计

介绍了一组合肥光源新高亮度模式的Lattice. 新的设计维持了储存环上所有元件和光束线位置不变,也没有加入新的元件. 取得了较低发射度. 所有直线节处的垂直方向β函数值都很小，适合插入件的运行. 跟踪计算表明新Lattice具有足够大的动力学孔径用于注入和储存粒子.     

Au/SiO2纳米多层薄膜的制备及其性质表征

利用多靶磁控溅射技术制备了Au/SiO2纳米颗粒分散氧化物多层复合薄膜.研究了在保持Au单层颗粒膜沉积时间一定时薄膜厚度一定、变化SiO2的沉积时间及SiO2的沉积时间一定而改变薄膜厚度时,多层薄膜在薄膜厚度方向的微观结构对吸收光谱的影响.研究结果表明:具有纳米层状结构的Au/SiO2多层薄膜在560nm波长附近有明显的表面等离子共振吸收峰,吸收峰的强度随Au颗粒的浓度增加而增强,在Au颗粒浓度相同的情况下,复合薄膜光学吸收强度随薄膜厚度的增加而增强.但当金属颗粒的浓度增加到一定程度时,金属颗粒相互接触,没有观察到纳米层状结构,薄膜不显示共振吸收峰特征.用修正后的M-G(Maxwell-Garnett)理论对吸收光谱进行了模拟,得到了与实验一致的结果.     

A New Method for the Analysis of Relative Permeability in Porous Media

By combining three-dimensional digital microtomography techniques with the lattice Boltzmann method,a new methodology is used to analyse the relative permeability of multiphase flow in porous media.The results indicate that the two coupling coefficients K12 and K21 have the same magnitude,therefore the Onsager reciprocity still holds,the results also agree well with the results of pipe flow numerical experiments.     

低维材料的热导率

一根导热棒 ,如果在它的两端存在温差 ,便会有热量从高温端流向低温端 .这种能量在固体中的传输 ,不是沿着棒按照直线路径完成的 ;其间 ,导热声子将遭遇到频繁的碰撞 ,从而产生热阻 .表征材料导热性能的物理量是热导率κ[单位是W /(m·K) ],而传输的热流密度 jQ(W /m2 )与温度梯度成正比 ,即 jQ=-κdT/dX .如果声子在传输过程中不经历散射 ,则不论导热棒多长 ,jQ 将不依赖于温度梯度 ,而仅仅取决于两端的温差 .引入声子平均自由程l ,经典理论给出 ,κ =(1/3)Cvl,其中C是单位体积材料的热容 ,v是声子的平均速度 .在低温下 ,对于无杂质缺…     

The Analysis and Improving of the Microwave Exciter in the Lower Hybrid Wave System

When we carry out lower hybrid wave heating and current driving plasma experiment at tokamak, we need mega-watt order of microwave power. The microwave signal at frequency of 2450 MHz is generated by a microwave exciter. According to the experiment＇s demands, the microwave exciter must provide output power of 1.5～ 2. 5 W with stabilized frequency and amplitude tobe used as the klystron input. Being amplified by the klystron, the microwave signal is transmitted through the transmitting system to the antenna and is emitted into the HL-2A tokamak. So we can see that the microwave exciter＇s function is very important to the lower hybrid wave heating and current driving plasma experiment.     

Experimental Study of Effect of Medium Boundary on Light Distribution in Tissue Phantoms

An experimental method for investigating the effect of medium boundary on distributions of light in the biological tissue phantom intralipid is presented. Measurements of distributions of light in intralipid-10% suspensions at 633 nm are described, in which a narrow collimated beam is incident on the surface of the phantoms and into the different depths inside of the phantoms. The experimental results show that the effect of the boundary of the medium on the curves geometry of light distributions is trivial, but the effect on intensity of scattering light is obvious, the maximal relative change of the energy fluence reaches 53.8% and the position of the peak of the energy fluence curve has a shift of 1.1 mm in the reverse direction of incident light for the phantom with albedo a=0.998, and the effect of the boundary is decreased with the increase of the absorption coefficients of tissue phantoms. The experimental results were analysed by the diffusion theory. These studies will be helpful for further understandings of the relation between the boundary of biological tissue and the distribution of light in tissue.     

EPT／BIIR橡胶密封材料制备及其性能

为了探索具备低水蒸气透过系数、低透气系数、低压缩永久变形以及良好耐老化性能的新型橡胶密封材料，鉴于影响并用胶性能的主要因素是共混相容性以及硫化速度，从实现并用胶优势互补角度出发，优选综合性能较好的三元乙丙橡胶（EPT）和溴化丁基橡胶（BIIR），开展了EPT／BIIR共混共硫化技术研究，并开展了DBPMH／HVA-2过氧化物硫化体系在EPT／BIIR并用胶中的应用研究。