scholarly journals Kagome bands disguised in a coloring-triangle lattice

2019 ◽  
Vol 99 (10) ◽  
Author(s):  
Shunhong Zhang ◽  
Meng Kang ◽  
Huaqing Huang ◽  
Wei Jiang ◽  
Xiaojuan Ni ◽  
...  
Keyword(s):  
Triangle Lattice

Bi-Material Re-Entrant Triangle Cellular Structures Incorporating Tailorable Thermal Expansion and Tunable Poisson's Ratio1

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Xiaobing He ◽  
Jingjun Yu ◽  
Yan Xie
Keyword(s):  
Thermal Expansion ◽  
Cellular Structure ◽  
Material Selection ◽  
Coefficient Of Thermal Expansion ◽  
Planar Lattice ◽  
Lattice Cell ◽  
Thermoelasticity Equation ◽  
Triangle Lattice ◽  
Temperature Load ◽  
The Relationship

Abstract Based on the bi-material triangle lattice cell, a new cellular structure, bi-material re-entrant triangle (BRT) cellular structure, is devised to incorporate tailorable coefficient of thermal expansion (CTE) and tunable Poisson's ratio (PR) properties by replacing the straight base of a triangle with two hypotenuse members. A general thermoelasticity equation to systematically build the relationship among the external force, the temperature load, and the deformation for planar lattice structures with bounded joints is derived and then embedded into a theoretical model for the devised BRT structure. Using assembled thermoelasticity equation, effective PR, Young's modulus, as well as CTE are computed. In order to guide designers to construct initial concepts, the design domain for coupling negative CTE and negative PR properties is plotted. The material-property-combination region that can be achieved by this cellular structure is determined within an Ashby material selection chart of CTE versus PR. Nine available combinations of CTE and PR properties are extracted and demonstrated with abaqus simulation.

Mixed Triangle Lattice Reinforced Membrane Antenna Reflector: Design and Analysis

AIAA Journal ◽  
2020 ◽  
Vol 58 (4) ◽  
pp. 1897-1900
Author(s):  
Qiang Tao ◽  
Changguo Wang ◽  
Ke Wang ◽  
Huifeng Tan
Keyword(s):  
Triangle Lattice ◽  
Antenna Reflector

scholarly journals The Effect of Anisotropy on Light Extraction of Organic Light-Emitting Diodes with Photonic Crystal Structure

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Xu ◽  
Yang Li
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Light Emitting Diodes ◽  
Extraction Efficiency ◽  
Organic Light Emitting Diodes ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Light Emitting ◽  
Organic Light ◽  
Triangle Lattice

The light extraction efficiency of organic light-emitting diodes (OLED) is greatly limited due to the difference in refractive indexes between materials of OLED. We fabricated OLED with photonic crystal microstructures in the interface between the glass substrate and the ITO anode. The light extraction efficiency can be improved by utilizing photonic crystals; however, the anisotropy effect of light extraction was clearly observed in experiment. To optimize the device performance, the effect of photonic crystal on both light extraction and angular distribution was investigated using finite-difference time domain (FDTD) method. We simulated the photonic crystals with the structure of square lattice and triangle lattice. We analyzed the improvement of these structures in the light extraction efficiency of the OLED and the influence of arrangement, depth, period, and diameter on anisotropy. The optimized geometric parameters were provided, which will provide the theoretical support for designing the high performance OLED.

scholarly journals Fabrication of Pascal‐triangle Lattice of Proteins by Inducing Ligand Strategy

2020 ◽  
Vol 59 (24) ◽  
pp. 9617-9623 ◽  
Author(s):  
Rongying Liu ◽  
Zdravko Kochovski ◽  
Long Li ◽  
Yue‐wen Yin ◽  
Jing Yang ◽  
...  
Keyword(s):  
Pascal Triangle ◽  
Triangle Lattice

scholarly journals Light-Output Enhancement of GaN-Based Light-Emitting Diodes with Three-Dimensional Backside Reflectors Patterned by Microscale Cone Array

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Huamao Huang ◽  
Jinyong Hu ◽  
Hong Wang
Keyword(s):  
Light Emitting Diode ◽  
Three Dimensional ◽  
Light Output ◽  
Bragg Reflector ◽  
Light Extraction Efficiency ◽  
Distributed Bragg Reflector ◽  
Etching Technique ◽  
Light Emitting ◽  
Triangle Lattice ◽  
Wall Plug Efficiency

Three-dimensional (3D) backside reflector, compared with flat reflectors, can improve the probability of finding the escape cone for reflecting lights and thus enhance the light-extraction efficiency (LEE) for GaN-based light-emitting diode (LED) chips. A triangle-lattice of microscale SiO2cone array followed by a 16-pair Ti3O5/SiO2distributed Bragg reflector (16-DBR) was proposed to be attached on the backside of sapphire substrate, and the light-output enhancement was demonstrated by numerical simulation and experiments. The LED chips with flat reflectors or 3D reflectors were simulated using Monte Carlo ray tracing method. It is shown that the LEE increases as the reflectivity of backside reflector increases, and the light-output can be significantly improved by 3D reflectors compared to flat counterparts. It can also be observed that the LEE decreases as the refractive index of the cone material increases. The 3D 16-DBR patterned by microscale SiO2cone array benefits large enhancement of LEE. This microscale pattern was prepared by standard photolithography and wet-etching technique. Measurement results show that the 3D 16-DBR can provide 12.1% enhancement of wall-plug efficiency, which is consistent with the simulated value of 11.73% for the enhancement of LEE.

Fabrication and Characteristics of Elliptical-Holes and near Elliptical Core Hexangular Lattice Photonic Crystal Fibers Based on Polymer

2011 ◽  
Vol 279 ◽  
pp. 151-156 ◽  
Author(s):  
Fei Liu ◽  
Hong Yan Gao ◽  
Qiang Xu ◽  
Ya Ni Zhang
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fibers ◽  
Structural Parameters ◽  
Polarization Mode Dispersion ◽  
High Birefringence ◽  
Triangle Lattice ◽  
Elliptical Holes ◽  
Elliptical Core ◽  
Polarization Maintaining ◽  
Crystal Fibers

The polarization properties of a new structure of high birefringence polarization maintaining photonic crystal fibers were explored, which were consisted of elliptical-holes and near elliptical core triangle lattice of hexangular structure based on polymer. The optical birefringence and the first order polarization mode dispersion were studied based on a full-vector localized basis function method. The numerical results show that the polarization properties are strongly dependent on structural parameters of the PCF. Furthermore, the proposed fiber was fabricated based on MMA monomer polymerization method in situ. So the proposed PCFs may be useful in the field of high birefringence polarization-maintaining optical communication.

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