基于十字形结构的相位梯度超表面设计与雷达散射截面缩减验证

基于十字形结构设计了一种在雷达波低频段极化不敏感的相位梯度超表面, 并通过仿真和实验进行了验证. 不同金属十字周期结构单元复合, 在超表面上形成附加的平行波矢分量, 对反射波波前进行调控, 获得超表面后向雷达散射截面积(RCS)缩减. 在设计波段内, 超表面在法线方向的单站RCS缩减达18.19 dB, 偏离法线-30°–+30°范围的单站RCS 平均缩减达8 dB; 仿真与实验结果符合较好.     

A low-frequency wideband metamaterial absorber based on a cave-disk resonator and resistive film

A low-frequency wideband, polarization-insensitive and wide-angle metamaterial absorber (MA) is designed, simulated and analyzed. This MA consists of a periodic arrangement of a cave-disk resonator (CDR), square resistive film (RF), and metal ground plane (GP) (a 0.8 mm-thick FR-4 dielectric spacer is sandwiched in between the CDR and RF, and another 1.2-mm thick FR-4 dielectric spacer is inserted in between the RF and GP). The simulated results based on finite integration technology (FIT) indicate that the absorption of the MA is greater than 90% and almost perfectly impedance- matched to the free space in the whole frequency range of 1 GHz-7 GHz. The simulated absorptions under the conditions of different polarization and incident angles indicate that this composite structure absorber is polarization-insensitive and wide-angled. Furthermore, the distribution of the power loss density indicates that the wideband absorptivity is mainly from the composite electromagnetic loss of the CDR and RF. This design provides an effective and feasible way to construct a low-frequency wideband absorber.     

酞菁钴/铁纳米填充母粒的制备及其稳定性

采用有机／无机原位复合技术，将酞菁钴（ＣｏＰｃ）的ＤＭＦ溶液与Ｆｅ（ＣＯ）５混合、加热回流制备出稳定的、规则球形的、平均粒径为１．４μｍ的酞菁钴／铁纳米填充母料。其内部为１０￣１５ｎｍ的α－Ｆｅ填充，外部为厚５０￣１５０的酞菁钴层包覆。纳米填充母粒的填３实密度为３．６６４ｇ／ｃｍ＾３，比饱和磁化强度为７６．３Ａｍ＾２／ｋｇ，矫顽力为４．１５ｋＡ／ｍ，纳米填充母粒的热稳定性高于１５０℃，与甲基硅油组     

具有局部畸变的常规势阱中玻色-爱因斯坦凝聚孤子的演化特性

运用数值模拟方法解Gross—Pitaevskii方程,研究了具有局部畸变（impurity）的常规势阱中玻色-爱因斯坦凝聚（BEC）孤子的演化特性,发现势阱的局部畸变对BEC孤子随时间演化的特性有重要影响,并且其影响与畸变的强度、势阱的幅度和势阱的类型有关。     

基于超材料与电阻型频率选择表面的薄型宽频带吸波体的设计

设计了三种类型吸波体, 分别为基于正方形金属贴片(square metal patch, SMP) 结构超材料吸波体、 电阻型频率选择表面(Resistance Frequency Selective Surface, RFSS) 吸波体和SMP与RFSS的复合结构吸波体. 采用FDTD算法分别对这三种类型吸波体的电磁波吸收特性进行数值模拟分析. 模拟得到的结果表明: 在整个2-30 GHz频率范围内, SMP吸波体, 通过几何参数的设计可以实现多频窄带强吸收; RFSS吸波体, 通过方块电阻的设计可以实现高频宽带强吸收, 但强吸收的带宽有限; SMP与RFSS的复合结构吸波体, 在3-25 GHz之间吸收率大于90%以上, 且宽频范围内与自由空间具有较好的阻抗匹配特性.     

阵列光纤在牙色测量系统中的应用

提出一种在牙色测量系统中应用阵列光纤色度传感器的新方法。该方法能够解决牙色测量中的复杂问题。采用该方法，可实现快速、精确的牙色测量，同时也能补偿平面光栅多色仪的色散。     

酞菁钴/铁纳米填充母粒组成的磁流变液性能

采用有机／无机原位（ｉｎ ｓｉｔｕ）复合方法制备得出本菁钴／铁纳米填充母粒，与甲基硅油组成磁流变液（ＭＲＳ）。ＭＲＳ的附加动态剪切应力（△τ）与分散介质浓度、外加磁场强度呈正比例关系；剪切速率对△τ的影响表明磁致流变为链状结构特征；△τ的对温度不敏感；ＭＲＳ对外加磁场有可逆的开／关变化特征，无记忆效应，磁流变响应时间小于０．１ｓ。     

Motion of a Bose-Einstein Condensate Bright Soliton Incident on a Step-Like Potential

The motion characteristics of a Bose-Einstein condensate bright soliton incident on a local step-like potential barrier are investigated analytically by means of the variational approach. The dynamics of the soliton-potential interaction is studied as well. Then the results are verified by direct numerical simulations of the Gross-Pitaevskii equation. It is found that a moving bright soliton can be reflected from or pass over a step-like potentiaI in a controllable fashion, the critical velocity depends on the width of the soliton and the parameters of the step, and the motion trajectory of the soliton does not depend on its phase. The atom density envelope of the soliton is changed as the result of the interaction between the soliton and the step-like potential.     

酞菁钴/铁纳米填充母粒组成的磁流变液性能

采用有机/无机原位（insitu）复合方法制备得出酞菁钴/铁纳米填充母粒,与甲基硅油组成磁流变液（MRS）。MRS的附加动态剪切应力（Δτ)与分散介质浓度、外加磁场强度呈正比例关系;剪切速率对Δτ的影响表明磁致流变为链状结构特征;Δτ对温度不敏感;MRS对外加磁场有可逆的开/关变化特征,无记忆效应,磁流变响应时间小于0.1s。     

涂层的热红外发射率计算模型

根据Kubelka-Munk 模型和Mie散射理论,解出了涂覆在高发射率衬底上的红外涂层里的辐射传输方程（RTE）,建立了涂层在热红外（8～14 μm）波段的发射率的计算模型.在运用铝粉粒子作为颜料粒子的情况下,根据计算结果,得出了涂层发射率与粒子半径、涂层厚度的关系,以及最优的粒子半径范围.