Polymer modulators based on Mach-Zehnder interferometers were designed, modelled, fabricated, and tested in this project. Built on a silicon-on-insulator wafer with 220 nm active silicon width, electron beam lithography, plasma etching, metal deposition and lift-off, and polymer deposition were used in the fabrication process. The simulated waveguide group index is 4.377 at 1.55 µm, the estimated r33 of the polymer modulator is 8.46 pm/V and the Vπ is 908 V. The measured group index is 4.541, indicating the fabricated feature size is smaller than the design.
Digital light processing (DLP) is a 3D printing technology that utilises a patterned light field to print 3D objects layer by layer, with fine features and reasonable scales. Due to the requirements in terms of functionalities, there are critical needs to print structures with finer features and broader materials options. This review focuses on the factors that are limiting these two perspectives. Techniques and recent progress to overcome challenges will be discussed as well. In the end, a brief outlook is given to motivate future research of DLP.
Two samples were characterised in this experiment using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectrometry (EDS). Based on the results, Sample A is identified as monoclinic WO3 powder with grain sizes from 10 to 60 microns and lattice parameters being compressed by 0.4%. Sample B is identified as WO3 film deposited on a substrate, the film has the majority of its nanostructures being nanorods, with a few nanobelts present. Both nanostructures have lengths less than 2 µm. The existence of any preferred orientation of growth with regard to the nanorods is discussed based on the results and the literature.
The sewerage system is held as an important part of city infrastructure, while the pipeline inspection technology based on closed-circuit television system (CCTV) is still offline and by human. This paper focus on the research topic of defect detection for intelligent sewer inspection with multi-label classification. We first use the image preprocessing methods to get the unified datasets, then deploy the framework of deep learning, and propose a multi-label classification method for defect detection. The experimental results show that our approach is a scalable and efficient method, and it will be used in the application systems.
Graphene/semiconductor nanocomposites were prepared by hydrothermal method, and the photocatalytic degradation performance of the composite was investigated. The mechanism of photocatalysis is proposed and analysed. It is believed that graphene can effectively improve the separation efficiency of photogenerated electron-hole pairs, improve the physical structure and light absorption performance of the catalyst, thereby improving the photocatalytic activity and degradation efficiency. Finally, the possible development trend of this kind of materials in the future was proposed.
In this paper, the history of superconducting materials and the superconducting phenomena are first briefly described, followed by a corresponding introduction to the characterization techniques that may be used in the study of superconducting materials. For example, scanning tunneling microscope is used to demonstrate the hole Fermi and electron Fermi surfaces in Fe-based superconducting materials. Fourier-transform infrared (FTIR) spectroscopy is used to study the symmetry of the superconducting band gap in Fe-based superconducting materials. Four-probe electrical transport measurements are used to measure the resistivity of superconducting materials. Angle-resolved photoemission spectroscopy (ARPES) is used to study the multi-orbital-to-electron structure of Fe-based superconducting materials, the symmetry of the superconducting band gap and its size, the various ordered states to electron. The use of ARPES to study the multi-orbital pair electron structure of Fe-based superconducting materials, the symmetry and size of the superconducting energy band gap, the structure of the various ordered states and the possible electronic coupling modes, etc. have made a great contribution to the exploration and study of superconducting materials.
The lane line is the most important traffic sign in road traffic and plays a significant function in restricting and guaranteeing the running of vehicles. Whether in the vehicle safety driving system or in the intelligent vehicle navigation based on machine vision, lane detection and recognition is a basic and necessary function module. This can enable future in-depth studies on intelligent transportation while also lowering the likelihood of traffic accidents.