一种用于TD-LTE电调智能天线的宽频移相器

针对TD-LTE系统中对电调智能天线的性能受移相器制约的问题,提出一种用于TD-LTE电调智能天线的宽频移相器。该移相器通过介质滑动来改变相位,通过局部阻抗匹配保证介质滑动过程中各支路阻抗的小幅波动,实现稳定的功率分配。仿真和实测结果表明,该移相器可同时工作在F（1880 MHz-1920 MHz）, A（2010 MHz-2025 MHz）,D（2555 MHz-2635 MHz）3个频段,电压驻波比（voltage standing wave ratio, VSWR）小于1.2,传输系数波动不超过±1dB,在最大相移时,相位离散性小于10%。     

电寻址液晶光阀系统上的叠栅条纹的观察与测量

利用电寻址液晶光阀系统生成叠栅条纹,对教学实验室中较难实现的圆形光栅及其动态叠栅条纹进行了模拟,并且利用电寻址的动态叠栅条纹测量了圆形光栅转速.此外,提出了远场衍射观察光线偏折的方法.     

Electrically tunable photo-aligned two-dimensional liquid crystal polarisation grating

Two-dimensional liquid crystal polarisation grating based on twist liquid crystal has been demonstrated and fabricated by polarisation holography in this paper. The maximal diffraction efficiency of the second order is up to 90%. And the two-dimensional liquid crystal polarisation grating has the properties of electrically tenability and polarisation tenability. The two-dimensional polarisation grating diffracts light into a spot array. Different direction diffraction light is with different polarisation states. The intensity of the different orders diffraction light is optically controlled.     

Anchoring effects on the electrically controlled optical band gap in twisted photonic liquid crystals

We study a one-dimensional twisted photonic liquid crystal (TPLC), consisting of various nematic liquid crystal cells adopting a twisted configuration intercalated by isotropic dielectric layers, submitted to a dc electric field (E^dc ) aligned along the periodicity axis. We write the corresponding Euler–Lagrange equations describing the nematic layer configuration. By assuming arbitrary anchoring quasi-planar boundary conditions, we calculate the equilibrium textures for the nematic, parametrized by the two types of strength of its interaction (polar and azimuthal) with the plane walls. We write the electromagnetic equations in a 4?×?4 matrix representation and using the transfer matrix formalism, we obtain the transmittance and reflectance coefficients for normal incidence as functions of the external electric field and anchoring strengths. We have observed a remarkable dependence of the electric field on the transmission and reflection spectra in opening and closing band gaps.     

一种适用于高频地波雷达的电小双频发射天线

设计了一款适用于高频地波雷达的发射天线,通过顶部加载螺旋线圈的方式实现了天线电小化,且利用参差调谐原理,同时在顶部加载两个不同长度螺旋线圈,使天线实现双频谐振。该天线电尺寸仅为0. 085λ,且兼顾双频段和高效率的优点。利用CST电磁仿真软件进行仿真设计并制作缩比模型进行验证,仿真与实测结果吻合良好。     

基于部件组合法的电大尺寸长方体目标RCS计算

介绍了高频法的物理光学法和物理绕射理论。针对特殊的电大尺寸目标,使用部件组合法对长方体目标雷达散射截面计算进行了相关推导、仿真。仿真结果与相关文献提供的结果相吻合,说明该方法对解决此类问题的RCS计算方法可行。     

钴镍双金属氢氧化物/石墨烯电控分离膜排异性回收废水中低浓度磷酸盐

采用滴涂结合电化学沉积两步法制备了一种具有优良电活性的三维花状钴镍双金属氢氧化物/石墨烯(CoNi-LDH/G)杂化膜,用于电控离子交换过程(electrically switched ion exchange,ESIX)吸附水溶液中低浓度的磷酸根(PO₄^3-)离子。结合 X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等对CoNi-LDH/G杂化膜进行形貌、组成及结构表征。采用电化学方法考察了该杂化膜在不同吸附电压、不同初始浓度、共存离子及不同pH值条件下对PO₄^3-吸附性能的影响。实验结果表明：通过调节氧化还原电位,即使在低浓度下,杂化膜对 PO₄^3-也具有良好的吸附性能,且可以在较宽的pH 值(4~10)范围内使用,同时受共存离子及其浓度变化影响甚小。此外,G 对 PO₄^3-的吸附容量为 1.10 mg·g^-1,CoNi-LDH 对PO₄^3-的吸附容量为11.74 mg·g^-1,二者吸附容量之和小于CoNi-LDH/G对PO₄^3-的吸附容量(16.25 mg·g^-1)。同时,结合O1s的XPS数据分析发现,CoNi-LDH/G杂化膜对PO₄^3-的吸附过程除了层间阴离子交换、PO₄^3-与层板金属离子配位的配体交换外,还存在G与CoNi-LDH之间的协同效应。     

A correlation of conductivity medium and bioparticle viability on dielectrophoresis-based biomedical applications

Dielectrophoresis (DEP) bioparticle research has progressed from micro to nano levels. It has proven to be a promising and powerful cell manipulation method with an accurate, quick, inexpensive, and label-free technique for therapeutic purposes. DEP, an electrokinetic phenomenon, induces particle movement as a result of polarization effects in a nonuniform electrical field. This review focuses on current research in the biomedical field that demonstrates a practical approach to DEP in terms of cell separation, trapping, discrimination, and enrichment under the influence of the conductive medium in correlation with bioparticle viability. The current review aims to provide readers with an in-depth knowledge of the fundamental theory and principles of the DEP technique, which is influenced by conductive medium and to identify and demonstrate the biomedical application areas. The high conductivity of physiological fluids presents obstacles and opportunities, followed by bioparticle viability in an electric field elaborated in detail. Finally, the drawbacks of DEP-based systems and the outlook for the future are addressed. This article will aid in advancing technology by bridging the gap between bioscience and engineering. We hope the insights presented in this review will improve cell suspension medium and promote DEP-viable bioparticle manipulation for health-care diagnostics and therapeutics.