A Method of Motion-Estimation-Based H.264 Video Coding Using Optimal Search-Range

Wireless Personal Communications - In multi-view video coding, inter-view and temporal redundancies decrease the coding efficiency and video quality, and they need to be eliminated. This paper...     

The effects of heat treatments on hardness and wear resistance in Ni-W alloy coatings

The relationship of processing parameters, microstructure, and mechanical responses of the electrodeposited nickel-tungsten alloys exposed to elevated temperatures in the range 700-1100 °C are investigated. Reverse pulse electrodeposition technique is employed to control the tungsten content and nanocrystalline grain size of the deposits. The application of heat treatment at 700 °C on the alloy with high tungsten content (22 at.%) and small grain size (3 nm) gives hardness enhancement and a small decrease in wear resistance. Prolonging annealing duration and increasing annealing temperature promote more grain growth and reductions of both hardness and wear resistance, despite the formations of secondary phases. For alloys with lower tungsten contents (6% and 13%) and larger grain sizes (13 and 56 nm), higher degrees of grain growth coupled with monotonic decline of hardness are observed. The study indicates that the electrodeposited nickel-tungsten alloys with a high tungsten content potentially serve as strong candidates for high temperature applications.     

Characterization of Colloidal Quantum Dot Ligand Exchange by X-ray Photoelectron Spectroscopy

Colloidal quantum dots (CQDs) are chemically synthesized semiconductor nanoparticles with size-dependent wavelength tunability. Chemical synthesis of CQDs involves the attachment of long organic surface ligands to prevent aggregation; however, these ligands also impede charge transport. Therefore, it is beneficial to exchange longer surface ligands for shorter ones for optoelectronic devices. Typical characterization techniques used to analyze surface ligand exchange include Fourier-transform infrared spectroscopy, x-ray diffraction, transmission electron microscopy, and nuclear magnetic resonance spectroscopy, yet these techniques do not provide a simultaneously direct, quantitative, and sensitive method for evaluating surface ligands on CQDs. In contrast, x-ray photoelectron spectroscopy (XPS) can provide nanoscale sensitivity for quantitative analysis of CQD surface ligand exchange. A unique aspect of this work is that a fingerprint is identified for shorter surface ligands by resolving the regional XPS spectrum corresponding to different types of carbon bonds. In addition, a deposition technique known as resonant infrared matrix-assisted pulsed laser evaporation is used to improve the CQD film uniformity such that stronger XPS signals are obtained, enabling more accurate analysis of the ligand exchange process.     

Fuzzy Adaptive Finite Time Command Filter Backstepping Control of Power System

International Journal of Control, Automation and Systems - In this article, an adaptive fuzzy finite time command filter control scheme is first proposed for a single machine infinite power system...     

具有高传输比的矩阵变换器结构研究

矩阵式交-交变频器具有无中间直流环节,可以任意调频,能量双向流动的诸多优点。但目前的矩阵变换器电压传输比多数只能达到0.866,限制了实用化进程。该文设计的泵式矩阵变换器结构,可以任意调节矩阵式变换器的传输比,从机理上解决了矩阵式变换器的传输比低的问题。     

H.264 Video Coding-Based Motion Estimation Architecture for Video Broadcasting from a Studio

Wireless Personal Communications - Motion estimation (ME) as a process in H.264 coding basically deals with huge number of image data and needs a lot of calculation so that it should be considered...     

一种自适应地域特征的乡村太阳能建筑设计方法 ——以2019"台达杯"获奖作品"阳光•风动"为引

以2019年"台达杯"获奖作品"阳光?风动"为引,阐述夏热冬冷地区适应地域特征的乡村太阳能建筑设计方法.从场地综合物理条件(日照、风场、地貌)出发,探讨建筑节能规划布局,以建筑体型、平面、立面、剖面、节点为设计基点,耦合地域典型乡土人文精神以及被动太阳能技术,形成将自然气候指导总体布局、传统地域人文精神控制建筑形式、被动式太阳能技术与地域精神耦合于一体的建筑设计思想,以期为乡村太阳能建筑提供一种设计方法.     

Sound velocities and elastic properties of PbTiO3 and PbZrO3 under pressure: First principles study

The elastic constants and sound velocities as a function of pressure for perovskite materials PbTiO₃ (PTO) and PbZrO₃ (PZO) were investigated by first principles calculations. Under ambient pressure, the calculated structural parameters were calculated and found to be in good agreement with known values. To study properties under pressure, PTO and PZO were calculated at several reduced volumes, each of which corresponds to the system under pressure. The C₁₁, C₁₂ and C₄₄ elastic constants are all found to increase with pressure for the pressure range studied. Because the sound velocities are directly derived from the elastic constants, the relationships between the sound velocities and pressure also follow similar trends. The longitudinal modes are all larger than those of the transverse modes.