Results 11 to 20 of about 180,808 (235)
Zhejiang Daxue xuebao. Lixue ban, 2022 建立了考虑潜伏期时滞和临时免疫期时滞的具有混合隔离策略的非线性计算机病毒传播模型，旨在帮助理解计算机病毒在网络中的传播规律。通过计算模型基本再生数，以不同时滞组合为分岔参数，研究了模型的局部渐近稳定性；利用中心流形定理和规范型理论分析了Hopf分岔的方向和周期解的稳定性，并通过数值模拟验证了理论分析的正确性。研究结果可为计算机病毒治理提供理论依据。
YANGFangfang(杨芳芳) +1 more
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Family Process, Volume 62, Issue 2, Page 671-686, June 2023., 2023 Abstract Investigations on the bidirectional relationships between parenting stress and child behavior problems are important to inform intervention strategies; however, prior research has provided inconsistent findings. Using a national sample of multi‐stressed single‐mother families from the Fragile Families and Child Wellbeing study, the present ...
Qingyu Jiang +3 more
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Shuitu Baochi Xuebao, 2021 以亚热带地区常绿阔叶树种樟树（Cinnamomum camphora）为研究对象，利用Grainer热扩散式探针技术，于2019年6月至2020年10月测定了樟树小时尺度的蒸腾速率，并同步监测了气象因子和土壤含水量，分析了樟树蒸腾在日间不同时段与主要气象因子的关系、时滞的变化特征以及时滞校正对蒸腾预测模型的影响。结果表明：蒸腾在生长季（6—10月）与太阳辐射的时滞回环呈逆时针，与饱和水汽压差和气温的时滞回环呈顺时针。利用Gauss方程拟合发现，2019年与2020年生长季蒸腾平均滞后于太阳辐射0.94 ...
夏银华 +4 more
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Zhejiang Daxue xuebao. Lixue ban, 2013 研究了一类区间时变时滞非线性广义系统的稳定性问题.基于Lyapunov稳定性理论，应用线性矩阵不等式和自由权矩阵方法，给出了使得系统正则、无脉冲且一致渐近稳定的时滞相关型稳定性新准则.结果表明，所给准则可有效判定区间时变时滞非线性广义系统的稳定性，它比已有的一些结果具有更小的保守性，并且通过数值实例进行了验证.
JIAOJian-min(焦建民)
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Optimizing biodiversity offsetting for habitat succession and colonization dynamics
Conservation Biology, EarlyView.Abstract Biodiversity offsetting aims to compensate for ecological losses from development through conservation and restoration. However, its long‐term outcomes under repeated impact–offset cycles remain uncertain. Using a conceptual forest succession model, we evaluated how offset outcomes are affected by interactions among compensation scale ...
Konstans Wells +4 more
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Zhongguo shiyan zhenduanxue, 2021 外周神经阻滞(NB)具有操作较简单,在术中患者血流动力学波动较小,术后患者能及早进食,能有效减少尿潴留等并发症的优点[1]。超声引导(UG)下神经阻滞克服了传统神经阻滞通过体表解剖标志定位,成功率低的劣势[2],可在超声图像中直接观察到需要阻滞的神经、神经周围的重要解剖结构以及局麻药在注射时的扩散情况,能够显著提高神经阻滞的成功率,同时也有效降低了并发症的发生率[3]。
宋峰, 于瑞萍, 高磊, 李凯
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The Problem With Problem Load: Reconceptualizing Load in the Multiple Streams Framework
Review of Policy Research, Volume 43, Issue 6, November 2026.ABSTRACT What happens when policymaking systems buckle under pressure, disrupting consensus and stalling decision‐making? Drawing on the Multiple Streams Framework, we show that the existing concept capturing this stress, Problem Load, has been both misinterpreted and overstretched.
Dana A. Dolan, Nikolaos Zahariadis
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Rare Metals, Volume 45, Issue 10, October 2026.ABSTRACT To achieve high‐value utilization of spent catalysts, we recovered copper (Cu) from Cu‐bearing spent catalysts via acid‐base leaching to fabricate CuO and systematically studied how calcination temperature affects their microstructure and humidity‐sensing performance. Characterizations show that CuO‐500 (calcined at 500°C) has a large specific
Cong Liang +9 more
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stability and robust stabilization of switched systems with time-delay [PDF]
, 2007 时滞切换系统是一类同时存在切换和时滞的系统，它的动态特性极为复杂。根据是否依赖于系统中的时滞，时滞切换系统的稳定性可分为时滞独立稳定和时滞依赖稳定。本文利用共同李亚普诺夫函数方法、多李亚普诺夫函数方法、平均驻留时间方法、线性矩阵不等式方法及完备性条件等，研究了时滞切换系统时滞独立稳定、时滞依赖稳定及状态反馈鲁棒镇定三个方面问题。全文概述如下：首先研究线性时滞切换系统的时滞独立稳定性问题。利用多李亚普诺夫函数方法，给出时滞切换系统时滞独立稳定的两个充分条件与两种切换律的设计方法 ...
罗正选
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Zhongguo shiyan zhenduanxue, 2020 目的探讨右美托咪定联合罗哌卡因行坐骨神经阻滞用于骨科创伤清创探查术的镇痛效果。方法 2018年9月-2019年6月60例因骨科创伤清创探查术行坐骨神经阻滞的患者随机分为R组、RD组及RL组各20例。坐骨神经阻滞R组给予0.3%罗哌卡因30ml、RD组给予0.3%罗哌卡因+右美托咪定0.75μg/kg共30ml、RL组给予0.3%罗哌卡因+右美托咪定0.5μg/kg共30ml。比较三组感觉和运动神经阻滞起效时间和阻滞维持时间。结果三组一般资料差异均无统计学意义(P>0.05)。与R组比较 ...
张静, 盛崴宣, 王劭恒, 关雷
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