Results 51 to 60 of about 10,576 (166)
Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 5, Page 624-632, May 2025.ABSTRACT Objectives Placental insufficiency contributes to many obstetric pathologies, but there is no bedside clinical tool to evaluate placental perfusion. We have developed a method to acquire multiple three‐dimensional (3D) power Doppler (PD) ultrasound (US) volumes of placental vasculature, with infrared camera tracking of the precise spatial ...
A. Xue +5 more
wiley +1 more source
Guangtongxin yanjiu, 2007 文章以Matlab为编程、分析工具,运用上、下行链路分离正序法对60 GHz射频光纤（RoF）系统进行功率设计、计算及分配,其中包括对RoF系统中光器件光功率的设计、无线传输部分电功率的估计以及对上行链路重要接收点的信噪比分析。通过系统的功率分配设计,对RoF系统的可实现性、合理性和稳定性做出必要的分析。最后,依据设计方案和功率计算结果,建立实际、可行的60 GHz RoF系统。
张奇, 林如俭, 修明磊
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Hydraulic traits are coordinated but decoupled from carbon traits in herbaceous species
Functional Ecology, Volume 39, Issue 5, Page 1302-1317, May 2025.Read the free Plain Language Summary for this article on the Journal blog. Abstract Plant hydraulic traits primarily define the water regulation strategy, thus enabling a better understanding of vegetation structure, function and dynamics under varying hydro‐environments.
Ruike Huang +9 more
wiley +1 more source
Joint energy efficiency and spectral efficiency optimization algorithm for UDN under the restriction of interference threshold and backhaul capacity [PDF]
, 2019 Aiming at the scenarios which consider the constraint of backhaul capacity restriction and interference threshold in ultra-dense networks (UDN),an integer linear programming (ILP) and Lagrangian dual decomposition (LDD) based joint optimization algorithm
Xu CHEN, Xuanli WU
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Resource allocation strategy of low earth orbit satellite oriented to user transmission difference [PDF]
, 2023 In the low earth orbit (LEO) uplink communication scenario, aiming at the different needs of different users for high capacity transmission (HCT) and high reliability transmission (HRT), the spectrum of two users with different needs was shared, a ...
Fatang CHEN, Miao HUANG, Yufeng JIN
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Large seeds as a defensive strategy against partial granivory in the Fagaceae
Journal of Ecology, Volume 113, Issue 3, Page 598-607, March 2025.Large seeds dispersed by scatter‐hoarding granivores, such as Fagaceae acorns, tolerate partial damage to achieve higher dispersal efficiency. By demonstrating that seed size itself acts as a defensive trait, the findings provide new insights into seed size diversity and evolution, highlighting how large seeds counterbalance reserve losses to evade ...
Si‐Chong Chen +5 more
wiley +1 more source
Gaoya dianqi, 2007 主要研究和探讨了变压器的功率损耗、两台变压器并联运行时的自然功率分配及最佳功率分配、两台变压器电阻的比值及功率分配与变压器电阻的关系、两台变压器负荷S与其内阻RB的关系,并且分析了变压器的最佳运行区、临界负荷和两台并联运行变压器的最佳运行,比较了各种型号的两台变压器组合后在运行一定时期的总费用,确定出费用的最低值。结果表明,当为SFL1-10000/35×2的组合时,总投资为220.8万元,变压器运行在最佳区。
陆地
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Functional Ecology, Volume 39, Issue 2, Page 621-634, February 2025.Read the free Plain Language Summary for this article on the Journal blog. Abstract Tropical forests are generally characterized by high species diversity and low soil phosphorus (P) availability. Although tropical plants have evolved adaptations to low soil P availability, we know relatively little about the strategies of different groups of species ...
Yingxu Fan +11 more
wiley +1 more source
Guangtongxin yanjiu, 2017 超表面材料在与光场相互作用时表现出独特的光学特性和许多有趣的物理现象,基于此材料制作的光电子功能器件对光场的调控能力有望被提升至新高。文章以光纤通信系统中的光功率分配应用为实例,提出了一种基于硅基超表面材料的新型光功率分配方案。首先,通过优化设计硅基超表面的单元结构,使其在1 4581 593nm波长范围内的相位偏振转化效率超过90%,而无偏振转化的效率则控制在1.2%以下;其次,研究了相邻硅纳米砖之间的光场耦合效应,将其对相位精度的影响降至最低;最后,利用优化设计的硅纳米砖结构 ...
王宇 +10 more
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H-CRAN中IRS辅助的D2D系统资源分配与RCG波束成形优化
Dianxin kexue以异构云无线电接入网（heterogeneous cloud radio access network，H-CRAN）中智能反射面（intelligent reflecting surface，IRS）辅助的端到端（device-to-device，D2D）通信系统为背景，研究了该系统中以和速率最大化为目标的资源分配与黎曼共轭梯度（Riemannian conjugate gradient，RCG）波束成形优化方法。以最大化系统和速率为优化目标，构造子信道复用系数 ...
许晓荣, 薛纪守, 吴俊, 包建荣
doaj +1 more source