Results 21 to 30 of about 7,753 (213)
Study on A Novel Frequency Tunable Piezoelectric Vibration Energy Harvesting Device [PDF]
, 2015 随着传感器技术、嵌入式计算机技术、无线通信技术的快速发展，无线传感器网络（WSN）得到了广泛应用。传统电源已无法满足无线传感器网络应用的要求，因此俘获环境能量并将其转换为电能为无线传感器供电成为传统电源的一种替代方案。环境中的振动能凭借能量来源广泛、收集方便的特点而成为了很具吸引力的环境能量源。振动能量的回收方式主要有三种，即电磁式、静电式和压电式。其中压电俘能方式可以直接将施加的应变能转化成电能，适用于各种尺度，结构相对简单，无需额外的电源，而且易于集成 ...
李营泰
core
Handling Homographs in Neural Machine Translation
, 2018 Homographs, words with different meanings but the same surface form, have long caused difficulty for machine translation systems, as it is difficult to select the correct translation based on the context.
Liu, Frederick, Lu, Han, Neubig, Graham
core +1 more source
, 2018 利用线性调频(Chirp)信号在水下通信中具有良好的抗噪声和抗多径特性,提出基于Chirp-BOK(binary orthogonal keying,二进制正交键控调制)扩频的水声通信系统。系统采用二进制正交键控调制以及匹配滤波接收器,利用正向调频信号和反向调频信号,结合BOK调制技术,实现适合水声环境的扩频通信系统。噪声信道和多径信道下的仿真实验结果表明,该系统具有良好的抗噪声和抗多径性能,适用于水声系统的扩频通信。国家自然科学基金项目(61701422);;福建省自然科学基金项目 ...
伊锦旺 +4 more
core +1 more source
Experiment and Dynamic Characteristics Simulation of Primary Frequency Regulation of a 660 MW Nuclear Power Unit [PDF]
, 2023 The operation mode of nuclear power units is very different from that of thermal power units, and the specific data on the response of relevant nuclear power units to grid frequency changes are relatively lacking at present.
TANG Ping
core +1 more source
Rare Metals, EarlyView.ABSTRACT Regulating negative parameters of metacomposites is mainly limited by their unclear mechanisms, which affects their practical applications in new sensing, communication, electromagnetic (EM) protection and other fields. This work proposes a dual‐functional competitive design strategy based on the waste corncob‐derived carbon/polyaniline ...
Qiuyun Yang +4 more
wiley +1 more source
Study on Millimeter-Wave Collision Avoidance Radar Based On Digital Beamforming [PDF]
, 2016 近年来，随着交通情况的日益复杂及人们对安全性的要求越来越高，防撞雷达的研究也进入一个快速发展的时期，不断涌现出新的方法和理论。防撞雷达常见的探测方式有超声波、激光等方式。这些方式存在穿透能力较差、作用距离近等缺点，实际工作效果并不是很好。毫米波方式波长短、抗干扰能力强，在雨雪天气下工作良好，且硬件设备具有体积小、重量轻的特点。另外，由于线性调频连续波雷达具有距离分辨率高、结构简单、无距离盲区等优点，因此，基于线性调频连续波方式的毫米波雷达在防撞雷达中得到广泛采用。 目前 ...
庄景波
core
The influence of the electrical boundary condition on domain structures and electrocaloric effect of PbTiO3 nanostructures [PDF]
, 2016 本文在基于金兹堡—朗道—德文希尔唯象理论的相场法理论下，应用有限差分方法及四阶龙格—库塔法数值求解，研究不同电学边界条件对铁电纳米点畴结构演化和热电温度效应的影响。本文所用的中间电学边界条件，可以用来表示表面电极与纳米点之间的黏合情况及电极对表面电荷的补偿情况，进而说明退极化电场和退极化电能对系统自由能的影响，不同以往的对退极化能进行权重处理，具有实际的物理意义。 当电学参数λ0为0时，中间电学边界可以退化为开路电学边界条件；当λ0趋向无穷大时，对应于短路电学边界条件，即表面电荷可充分补偿。λ0的值越大，
陈志英
core +1 more source
Rare Metals, EarlyView.ABSTRACT MCrAlX coatings are widely used as bond coats in thermal barrier coating systems to protect turbine blades from high‐temperature oxidation. However, their oxidation resistance is often restricted by uncontrolled microstructures, surface roughness, and aggregation of reactive elements (REs). In this study, high‐repetition‐rate femtosecond laser
Wei Qian +7 more
wiley +1 more source
Study on Target Detection Method by Coherent Integration for Frequency Modulation Coded Radar Systems [PDF]
, 2016 在现代战场上，高速低可侦测性目标以及各种电子干扰手段的出现对雷达的目标探测性能提出了更高的要求。调频编码雷达作为一种新型的高距离分辨率雷达，具有数据利用率高、对雷达瞬时带宽要求不高以及抗干扰性能强的优点。为了增强调频编码雷达对微弱目标的检测能力，进一步研究调频编码雷达的相干积累检测方法具有重要意义。因此，本文主要开展了如下创新工作： (1)针对调频编码雷达，提出了一种基于运动补偿的相干积累检测方法。首先对调频编码雷达的回波信号进行建模，利用最大似然估计 ...
王智灵
core
Research on Energy Storage Planning Method Considering the Dual Constraints of Peak Shaving and Frequency Modulation [PDF]
, 2023 [Introduction] In the process of building a new power system, renewable energy will maintain a high-speed development trend. Along with large-scale grid connection of renewable energy sources such as wind energy and photovoltaic energy, the randomness ...
Lei CHEN, Ting WEN
core +1 more source