Results 31 to 40 of about 928,217 (165)
Ultrasound in Obstetrics &Gynecology, Volume 67, Issue 5, Page 613-622, May 2026.ABSTRACT Objectives To evaluate the effect of aspirin on gestational age at delivery due to preterm pre‐eclampsia (PE) in women with chronic hypertension (CH), to assess the predictive performance of the Fetal Medicine Foundation (FMF) first‐trimester competing‐risks model for preterm PE in this high‐risk group and to evaluate how parity, previous PE ...
D. L. Rolnik +23 more
wiley +1 more source
智能科学与技术学报, 2020 边缘智能计算是指将用户节点产生的计算密集型任务卸载到计算能力更强的边缘服务器上进行处理，而基于无人机的边缘智能计算是指在此基础上结合智能无人机平台，利用该平台机动性强、易于部署的优点，更加快速灵活地为地面用户设备提供边缘计算服务。此外，无人机也可作为用户节点，将其计算密集型任务卸载到地面边缘服务器上来执行。针对无人机作为用户节点和边缘服务器两种不同场景，根据最小化能耗、最小化时延和最大化效用等不同的优化目标对当前基于无人机的边缘智能计算研究进行了分类和总结，并对下一步的研究方向进行了思考与展望。
董超, 沈赟, 屈毓锛
doaj
Food and Energy Security, Volume 15, Issue 2, March/April 2026.ABSTRACT Net photosynthetic rate (Pn) serves as a key indicator for evaluating plant growth and yield. In order to explore an effective method for monitoring winter rapeseed Pn using unmanned aerial vehicle (UAV) multispectral technology, the winter rapeseed was taken as the research object and the multispectral images were obtained through UAVs in ...
ChengYang Ni +7 more
wiley +1 more source
Integrative Conservation, Volume 5, Issue 1, Page 33-45, March 2026.The Asian Songbird Crises negatively affects so‐called master birds, species that are used to increase the song complexity of competitive songbirds. We assessed the trade in a master bird, the crested jayshrike, in Indonesia before and after its legal protection.
Vincent Nijman +11 more
wiley +1 more source
Gaoya dianqi, 2013 无人机数据链系统是无人机系统的核心组成部分,为了验证其在超宽带电磁脉冲（UWB）场环境下的安全性及可靠性,在开阔场搭建了UWB电磁脉冲辐射系统。利用UWB电磁脉冲辐射系统对无人机数据链系统进行辐照效应实验。实验结果表明:单次触发的UWB辐射场不会对无人机数据链系统产生干扰;在连续触发条件下,无人机数据链系统会出现失锁现象,此效应与触发频率和辐照场强有关,且辐照场强与触发频率成反比关系。通过分析得知,无人机数据链路系统受UWB电磁脉冲辐射场干扰的能量耦合通道为"后门"耦合。
张涛, 陈亚洲, 田庆民, 程二威
doaj
, 2017 本发明属于无人海洋机器人领域，具体地说是一种无人海洋机器人操舵装置，包括舵承组件、舵叶及分别位于机器人载体内部的液压缸支座、后转轴、液压缸、前转轴、舵柄，液压缸支座安装在机器人载体内部，液压缸通过后转轴与液压缸支座连接；舵承组件穿过机器人载体上开设的舵承孔，并安装在机器人载体上；舵柄的一端通过前转轴与液压缸的活塞杆连接，另一端与舵承组件中的舵轴位于机器人载体内部的一端相连，舵叶安装在舵轴位于机器人载体外部的另一端连接。本发明应用平面二级杆组运动原理设计，结构设计紧凑简单、可靠性高，可承受双向轴向载荷 ...
郑荣 +4 more
core
How New Issues Become Polarized: Partisan Triggers and Subsystem Shopping in Early AI Policymaking
Policy &Internet, Volume 18, Issue 1, March 2026.ABSTRACT Early AI policymaking in the United States appeared bipartisan, but subsequent developments raise the question of whether AI policy will become more polarized over time. To examine how partisanship takes root around novel policy issues, we perform a mixed‐methods study, analyzing survey data from 129 state legislators in 44 states and ...
Robin Jacobson +2 more
wiley +1 more source
, 2018 本实用新型属于无人直升机技术领域，具体地说是一种无人直升机降落辅助装置。包括通断控制电路及连接在通断控制电路中的电磁铁模块，其中电磁铁模块设置于无人直升机的起落架上，通断控制电路设置于无人直升机的机舱内，并且与无人直升机的飞行控制系统连接。所述通断控制电路包括导线、锂电池及继电器开关，锂电池和继电器开关通过导线连接，形成闭合控制回路，电磁铁模块连接在闭合控制回路中。本实用新型实现无人直升机在具有六自由度运动的船甲板上降落并锁定 ...
余鑫鑫 +6 more
core
Laser‐Driven Halide Exchange and High‐Resolution Multicolor Patterning of Perovskite Films
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Translating the excellent properties of metal halide perovskites (MHPs) into practical flexible optoelectronic devices requires high‐resolution multicolor patterning techniques that are compatible with post‐fabrication processing. However, such a capability has remained elusive.
Shu Yang +6 more
wiley +1 more source
Dianxin kexue针对传统的可重构智能表面（reconfigurable intelligent surface，RIS，也称智能超表面）在无人机辅助安全通信中存在的灵活性不足和系统安全保障能力不强的问题，以及当前无人机半双工通信系统普遍面临的频谱利用率低和通信效率低的挑战，提出了一种空中可重构智能表面（aerial reconfigurable intelligent surface，ARIS）与全双工无人机的双机协同解决方案，旨在提升面对地面窃听者时的通信安全性和效率。联合优化用户通信调度、传输功率 ...
罗俊松1, 黄平1, 罗欣悦1, 赖欢1, 多滨1, 袁晓军2
doaj +1 more source