The far-infrared absorption of a periodic 2DEG in the transition regime between weak and strong modulation

We study the optical absorption of arrays of quantum dots and antidots in a perpendicular homogeneous magnetic field. The electronic system is described quantum mechanically using a Hartree approximation for the mutual Coulomb interaction of the electrons. The evolution of the absorption is traced from the homogeneous to the strongly modulated case identifying the ensuing collective modes, the magnetoplasmons, and their correlations with inherent length scales of the system.     

Banach空间的型与B值随机元阵列完全收敛性的注记

该文在随机元阵列随机有界于某非负随机变量的条件下,进一步讨论了完全收敛性与Banach空间p型性质的等价性.     

一种用于LSPR传感器的准正方型银纳米颗粒阵列制备

首先控制聚苯乙烯纳米球(PS球)乳液在基片上的干燥温度,采用自组装方法,使用单一粒径的PS球制备出单层的PS球亚稳态正方排列结构模板。然后,在模板上通过磁控溅射法沉积一层银膜。利用纳米球光刻技术,去掉PS球模板得到二维正方点阵排列的准正方形银纳米颗粒阵列结构。     

Wet Purification of Aligned Carbon Nanotube Arrays and Its Impact on the Morphology of the Carbon Nanotube Arrays

A simple acid treatment method was applied to remove the catalyst impurities and other residues contaminated in the vertically aligned carbon nanotube arrays. We demonstrated that acid treatment was an efficient approach for aligned carbon nanotube purification. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the morphology of the aligned carbon nanotube arrays and to determine the efficiency of the purification. Using hydrochloric acid could efficiently eliminate catalyst impurities and retain the original structures of the aligned carbon nanotube arrays. The method provided a simple, economical, and effective way to purify the aligned carbon nanotubes, and it would promote the applications of vertically aligned carbon nanotube arrays in electronic field.     

基于变积分时间的红外焦平面非均匀性校正算法研究

针对两点温度定标算法在应用过程中曝露的问题,提出了基于变积分时间的红外焦平面非均匀性校正算法.该算法先对图像进行非线性压缩,转换为线性图像,再利用红外焦平面阵列探测元的响应特性与积分时间之间的关系,采用改变积分时间的方法拟合红外焦平面探测器的平均响应特性曲线,进行两点校正,然后对结果进行取指数操作,即得到原图非均匀校正后的图像.分别利用两点温度定标法和变积分法对航拍红外图像进行校正效果验证,同时进行了不同校正算法的非均匀性适应性评价实验.实验结果表明新算法计算量小,校正准确度高,反应速度快,并在一定程度上解决了大动态范围下响应非线性对校正性能的影响,具有很好的工程应用价值.     

Fabrication and performance of MMW and SMMW platelet horn arrays

Future spaceborne millimeter and sub-millimeter wave sensing systems will require the sensitivity and resolution only achievable with large focal plane array receiving systems. A technique has been developed for the low cost fabrication of large arrays of millimeter and sub-millimeter wave corrugated feed horns. These arrayed horns exhibit high efficiency and symmetrical receiving patterns and are compatible with integrated receivers. W-band test results of a 3×3 array are presented.     

A combinatorial approach to cartograms

A homeomorphism from ² to itself distorts metric quantities, such as distance and area. We describe an algorithm that constructs homeomorphisms with prescribed area distortion. Such homeomorphisms can be used to generate cartograms, which are geographic maps purposely distorted so their area distributions reflects a variable different from area, as for example population density. The algorithm generates the homeomorphism through a sequence of local piecewise linear homeomorphic changes. Sample results produced by the preliminary implementation of the method are included.