Results 11 to 20 of about 16,108 (208)
Rare Metals, EarlyView.ABSTRACT The similar physicochemical properties of alkali metal elements make the co‐enrichment and precise separation of Cs+ and Rb+ in complex brine systems highly challenging. Here, an all‐inorganic strategy is proposed, which achieves efficient enrichment and precise separation of Cs+ and Rb+ in high‐salt systems by constructing Sr2+/Ba2+‐based ...
Kang Li, Ruixin Ma, Shina Li
wiley +1 more source
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract The nested subset pattern (nestedness) has been widely used to explain species distributions in island and fragmented systems. Mountain sky islands serve as critical natural laboratories for understanding the evolutionary consequences of geographic isolation and climate
Caiwen Zhang +5 more
wiley +1 more source
Research of Brain-Computer Interface Based on Motor Imagery Feature Extraction and Pattern Classification [PDF]
, 2015 近些年来，随着神经科学、信号处理、计算机科学等领域的不断地深入发展，作为这些学科的交叉学科——脑机接口，目前已成为了当前国际上科学研究的热门领域。脑机接口是一种不同于人脑神经与肢体肌肉组织的正常通道，而是通过解析人脑神经活动信息来与外界设备交流的通讯控制系统。由于脑电信号具有幅值微弱、非平稳、噪声干扰强等特点，导致该类信号特征提取与模式分类的复杂性以及构建在线脑机接口系统的困难。经过充分调研与研究，本文采用了对二分类与四分类脑机接口更加有效的特征提取方法，并构建一套基于运动想象的在线足球射门脑机接口系统。
蔡燕福
core
Dianci bileiqi, 2022 大部分的电压致热型设备由于温升不明显，故障判断难度较大，并且红外图像受到背景复杂，尺寸多的影响，导致红外图像特征提取困难，另外，大多数现有的检测工作依靠人工判别，且存在判断分歧。目前，代替人工判别的研究中，许多只利用单一的特征来表征热图像中的故障特征。针对此类问题，笔者提出一种基于多特征融合的电压致热型设备故障提取方法。此方法将红外图像多故障目标检测算法和多特征融合算法相结合，建立动态决策准则。首先提取红外图像的三种典型特征，包括颜色、纹理和轮廓特征，继而通过融合算法(串行融合、并行融合和DCA ...
doaj
Research on Sand Dumping Detection of Harbor Dredging Based on Signal Enhancement and Feature Extraction [PDF]
, 2016 随着海洋经济发展，各国对港区建设和航道维护愈加重视。但是，在利益驱使下，疏浚驳船常常在非指定区倾倒泥沙，导致航道内泥沙淤积甚至断航，航道维护成本增加和生态坏境破坏。目前，国内普遍采用安装摄像头、吃水线检测等监控方法，但易受人为破坏和环境因素的影响无法获得好的效果。国外采用更改倾倒区和自然处理的手段并不适用于我国流域众多的国情。因此，航道管理部门急需一种非接触式、稳定可靠的监控手段，以保证疏浚工程作业的质量。 本文根据混浊海水声吸收的原理，周期性地发送和接收Chirp探测信号 ...
钟张婷
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International Journal of Applied Linguistics, EarlyView.ABSTRACT This computational linguistic study analyzes 8743 Rednote posts to examine how sentiment, emotion, and content domain collectively shape social comparison dynamics on social media. We identify four key findings: (1) an emotional gradient, where upward comparison content exhibits the highest sentiment scores and downward comparison the lowest; (
Michelle Mingyue Gu +7 more
wiley +1 more source
Dolphins whistle contour automatic extraction and recovery [PDF]
, 2015 海豚是一种高智商的水生哺乳动物，它们使用自己独特的“语言”——哨声来进行互相交流。要想理解海豚的语言，就必须要对海豚哨声进行分析研究。当前对海豚哨声的分析研究大多是基于哨声语谱图进行的，但语谱图中哨声轮廓与背景噪声混合在一起，不仅导致目前对哨声的分割、提取等预处理都是用人工方式进行，同时也给后续的实验造增加了难度。如果对语谱图中的哨声轮廓进行去噪、特征提取和修复等自动化预处理，就能实时进行海豚哨声与背景噪声的分离，获得一个完整的海豚哨声轮廓。这不仅节约了人工提取花费的时间，也有利于海豚哨声的个体识别 ...
吴道曦
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Synthesizing Empirical Research on Learner Metacognition in Second Language Writing
International Journal of Applied Linguistics, EarlyView.ABSTRACT Despite considerable research interest in learner metacognition in second language (L2) writing, there is not yet a review that synthesizes the existing empirical findings and discusses their implications. To fill the void, this systematic review synthesized 39 empirical studies on learner metacognition in L2 writing and examined their salient
Chen Li, Icy Lee, Zhicheng Mao
wiley +1 more source
Design and Implementation of Face Recognition System Based on OpenCV and JavaCV [PDF]
, 2016 随着计算机和互联网的不断发展，在人工智能领域思想理论取得了一系列的发展，作为人工智能领域中发展较为突出的人脸识别技术取得了较为快速的发展。随着国家经济急速的发展，在社会各个领域对人脸识别技术的要求不断增加。人脸识别技术应用领域广泛，可以毫不夸张的说几乎可以覆盖整个社会的各个方面。上至国家信息安全，下到民生建设都有广泛的应用领域。现如今的生活中主要使用输入密码、插卡、获取口令等方式来保护个人信息和财产安全，这些传统的方法具有安全性低、易忘、易丢等缺点。随着技术的发展这些传统验证方式受到新技术的挑战 ...
江桥
core
Partisans' evaluations of unconstitutional legislative activity
Policy Studies Journal, EarlyView.Abstract In this research note, we examine whether public evaluations of a policy depend on the constitutionality of the process by which that policy was passed. We observe whether people's views depend on accusations that a policy was passed in violation of a state constitution's single subject rule, and whether the effect of that accusation depends ...
Kevin K. Banda +2 more
wiley +1 more source