广义次指数密度的两个新的等价条件

得到了广义次指数密度的两个新的等价条件,刻划了它们的卷积封闭性和卷积根封闭性.     

Nanobridged rhombic antennas supporting both dipolar and high-order plasmonic modes with spatially superimposed hotspots in the mid-infrared

Mid-infrared antennas (MIRAs) support highly-efficient optical resonance in the infrared, enabling multiple applications, such as surface-enhanced infrared abso...     

Extended Kalman Filter-based localization algorithm by edge computing in Wireless Sensor Networks

The Extended Kalman Filter (EKF) has received abundant attention with the growing demands for robotic localization. The EKF algorithm is more realistic in non-linear systems, which has an autonomous white noise in both the system and the estimation model. Also, in the field of engineering, most systems are non-linear. Therefore, the EKF attracts more attention than the Kalman Filter (KF). In this paper, we propose an EKF-based localization algorithm by edge computing, and a mobile robot is used to update its location concerning the landmark. This localization algorithm aims to achieve a high level of accuracy and wider coverage. The proposed algorithm is helpful for the research related to the use of EKF localization algorithms. Simulation results demonstrate that, under the situations presented in the paper, the proposed localization algorithm is more accurate compared with the current state-of-the-art localization algorithms.     

Molecular Forcefield Methods for Describing Energetic Molecular Crystals: A Review

Energetic molecular crystals are widely applied for military and civilian purposes, and molecular forcefields (FF) are indispensable for treating the microscopic issues therein. This article reviews the three types of molecular FFs that are applied widely for describing energetic crystals—classic FFs, consistent FFs, and reactive FFs (ReaxFF). The basic principle of each type of FF is briefed and compared, with the application introduced, predicting polymorph, morphology, thermodynamics, vibration spectra, thermal property, mechanics, and reactivity. Finally, the advantages and disadvantages of these FFs are summarized, and some directions of future development are suggested.     

支持热调节、输入过压保护功能的安全增强型线性锂离子电池充电器

从电量和容量两方面来讲,锂离子电池的能量密度都很大,因此广泛应用于便携式设备.由于高集成度线性电池充电器简单易用、成本低、体积小,因此广泛应用于为单体锂离子电池充电.     

基于P89LPC922的Mifare卡预付费智能水表的设计与实现

介绍了一种低功耗智能水表的设计方案。该水表以Philips公司的低功耗单片机P89LPC922为控制芯片,配有电源电路、阀门驱动电路、计量电路、Mifare卡的读写电路、液晶显示等部分。根据该方案设计的水表已投入市场。     

YAM机、T特性设备视放板回路的调整和对彩管色平衡的影响

本文主要讲述了视放回路的原理、调整及其对彩管会聚、色平衡的影响.为解决视放回路过长而引起的视频延迟现象,专门设计了一套视频放大板,其中包括了预视放回路、视频延迟回路、视频放大输出部分及EK恒压源回路等.     

An Efficient Trajectory Planning for Cellular-Connected UAV under the Connectivity Constraint

Unmanned Aerial Vehicles(UAVs)acting as aerial users to access the cellular network form a promising solution to guarantee its safe and efficient operations via the high-quality communication.Due to the flexible mobility of UAVs and the coverage range limits of ground base station(GBS),the signalto-noise ratio(SNR)of the communication link between UAVs and GBS will fluctuate.It is an important requirement to maintain the UAV’s cellular connection to meet a certain SNR requirement during the mission for UAV flying from take off to landing.In this paper,we study an efficient trajectory planning method that can minimize a cellular-connected UAV’s mission completion time under the connectivity requirement.The conventional method to tackle this problem adopts graph theory or a dynamic programming method to optimize the trajectory,which generally incurs high computational complexities.Moreover,there is a nonnegligible performance gap compared to the optimal solution.To this end,we propose an iterative trajectory optimizing algorithm based on geometric planning.Firstly,we apply graph theory to obtain all the possible UAV-GBS association sequences and select the candidate association sequences based on the topological relationship among UAV and GBSs.Next,adopting the triangle inequality property,an iterative handover location design is proposed to determine the shortest flight trajectory with fast convergence and low computation complexity.Then,the best flight trajectory can be obtained by comparing all the candidate trajectories.Lastly,we revealed the tradeoff between mission completion time and flight energy consumption.Numerical results validate that our proposed solution can obtain the effectiveness with set accuracy and outperform against the benchmark schemes with affordable computation time.     

Q-switched mode-locking femtosecond all-fiber laser based on Er3+/Yb3+ codoped phosphate fiber

A Q-switched mode-locking femtosecond all-fiber laser based on a 2 cm long homemade Er³⁺/Yb³⁺ codoped phosphate glass fiber has been reported. By using the nonlinear polarization evolution technique, a nearly 100% modulation depth of mode-locking pulse train is achieved. At a pump power of 410 mW, the energy of each Q-switched envelope, whose width is about 220 μs, is 10 μJ, while the duration of mode-locking pulse within the Q-switched envelope is 318-fs.