Results 51 to 60 of about 1,240,523 (178)

Cross‐stage single‐cell and spatial metabolome analyses reveal periderm specialization and tanshinone biosynthesis in Salvia miltiorrhiza roots

open access: yesNew Phytologist, Volume 251, Issue 3, Page 1267-1282, August 2026.
Biosynthesis and accumulation of tanshinones in the periderm of Salvia miltiorrhiza during secondary root growth. Summary Perennial herbs develop long‐lived roots that undergo repeated cycles of secondary growth, during which the periderm functions as a protective barrier and a major site of specialized metabolite accumulation.
Licheng Liu   +19 more
wiley   +1 more source

基于双目重建不确定性的动态特征滤除

open access: yes, 2009
提出了一种基于双目视觉三维重建不确定性的环境动态特征滤除方法。针对利用立体视觉系统对机器人进行运动估计时,环境中的动态目标和环境静态背景与机器人的空间相对运动具有不一致性,将严重影响系统的精度的问题。根据动态目标与环境背景的空间运动不一致性,分析立体视觉三维重建的不确定性,利用重建的不确定性估计机器人与环境间的相对运动,通过随机一致性方法(RANSAC)滤除图像中的环境动态特征 ...
杜英魁, 韩建达, 唐延东
core  

避雷器热等价性及复合外套避雷器稳态热特性初探

open access: yesDianci bileiqi, 2013
金属氧化物避雷器的热特性决定着避雷器长期带电运行的稳定性。通过对避雷器最新标准中关于热特性相关内容的解析,指出了避雷器的热特性实质包括了稳态热特性和瞬态热特性,验证比例单元与避雷器具有稳态热等价性是进行动作负载等试验的前提,给出了试验项目与评价热特性的关系,同时指出了现有标准中在试品选取方面的某些不妥。通过试验研究了复合外套避雷器的稳态热特性,给出了几点常见的热特性规律。
桑建平
doaj  

Basic income trials and the politics of scale: A research agenda

open access: yesPolicy Studies Journal, Volume 54, Issue 3, August 2026.
Abstract The growing popularity of basic income has led to extensive trials of the policy in numerous settings across the world. However, analysis of the politics of basic income, and in particular the political dynamics preceding and resulting from trial programs, lags. In response, we propose a research agenda that uses political scale to investigate
Jurgen De Wispelaere   +2 more
wiley   +1 more source

关于土在重复载荷下动态特性的综述

open access: yes, 1988
本文对土在重复载荷下的动态特性,包括模量、阻尼、变形、强度、疲劳、本构关系、液化以及试验方法作了较全面的综述 ...
曾春华
core  

一种印制板罗氏线圈的结构参数和电磁参数影响研究

open access: yesGaoya dianqi, 2007
设计了一种具有单面线圈结构的印制板罗氏线圈,对其结构参数和电磁参数之间的相互影响以及它们对线圈动态特性的影响进行了研究,并归纳了影响其电磁参数和动态特性的重要因素。获得了所设计的具有单面线圈结构的印制板罗氏线圈的幅频特性和相频特性的试验曲线,利用它测量了脉冲功率源中的脉冲大电流。实验表明,所得出的有关分析和优选印制板罗氏线圈的结构参数和电磁参数的分析方法,对于快速设计具有合理结构、最优电磁参数和良好动态特性的印制板罗氏线圈,具有指导价值。
李维波   +4 more
doaj  

Spatiotemporally Adaptive Bilayer Silk Fibroin–Polyvinyl Alcohol–Metformin Composite Coating on Biodegradable Zinc for Orthopedic Applications

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Biodegradable zinc (Zn)‐based materials are considered promising candidates for orthopedic applications because of their favorable mechanical properties, controllable biodegradability, and good biosafety profiles. However, their clinical translation is limited by early‐stage corrosion‐induced cytotoxicity and inflammation, as well as ...
Jinlong Mao   +9 more
wiley   +1 more source

有关压力传感器动态校准和动态性能评价的几个问题

open access: yes, 1981
在本文中,作者根据简单的线性系统分析和实践中的体会,对压力传感器的动态校准和动态性能的评价提出下列几点看法:(1)阶跃压力是较理想的动态校准压力源;激波管可以作为标准动态压力标准装置(微压传感器除外)。(2)压力传感器的主要动态性能指标为:上升时间、超调量、振荡频率或谐振频率、冲击加速度灵敏度。(3)压力传感器的校准可采用静态校准和动态校准相结合的方法,没有必要在整个量程范围内进行动态校准。用“动态灵敏度 ...
张挺
core  

Chloride Coordination‐Engineered Fe–NC Catalyst for Directed Singlet Oxygen Generation Through Peroxymonosulfate Activation

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Heteroatom coordination regulation is an effective strategy to enhance Fenton‐like catalysis of single atom catalysts, yet its impact on the local microenvironment of active sites still requires in‐depth investigation. Herein, Cl2–Fe–NC catalysts with axial Cl coordination are prepared.
Jing‐Hao Yan   +6 more
wiley   +1 more source

乘波体荷兰滚模态特性研究

open access: yes, 2017
乘波体非轴对称、扁平、大长细比的几何外形特点决定了其存在严重的横航向耦合动稳定性问题。目前对乘波体横航向稳定性的研究还相对较少,且一般只针对单一外形,对飞行器设计未能获得有指导意义的定性、定量结论。以幂次乘波体为研究对象,首先引入设计参数kw和φ描述其外形特点,然后结合CFD数值模拟和Kriging代理模型,获得了整个设计参数空间内乘波体的静/动导数,进而通过求解飞行动力学耦合方程特征根获得乘波体的横航向耦合动稳定荷兰滚模态特性。定义了荷兰滚动稳定性导数的概念,推导了荷兰滚阻尼近似表达式 ...
刘文, 张陈安, 王发民
core  

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