Results 51 to 60 of about 20,406 (216)

桩–土动力相互作用问题中桩身刚度的影响效应研究 [PDF]

open access: yes, 2011
通过开展2类刚度差异较大的桩基础的离心机动力模型试验,系统地讨论柔性桩和刚性桩的地震反应差异,以及周围土体对桩体的不同作用效应。对于柔性桩,周围土体的作用主要体现在对桩的约束效应上;然而对于刚性桩,土体更大程度上对桩体施加附加惯性力的作用,以致桩筏基础的周期明显高于无土时的周期;针对柔性桩和刚性桩显著的地震反应差异,巧妙地提出用桩筏结构自振频率wp r界定两者的行为 ...
裴建良, 马亢
core  

Oxygen Vacancy Engineering of Ultrafine ZnAl2O4 Nanoparticles as a Robust Protective Layer for Dendrite‐Free and Long‐Lifespan Aqueous Zn Metal Anodes

open access: yesRare Metals, EarlyView.
ABSTRACT Aqueous zinc‐ion batteries (AZIBs) hold great promise for safe and sustainable energy storage, but their commercialization is impeded by severe Zn dendrite growth and interfacial instability. To address these challenges, we propose a defect engineering strategy employing ultrafine ZnAl2O4 (ZAO) nanoparticles (∼5 nm) with oxygen vacancy defects
Yilun Ren   +9 more
wiley   +1 more source

毛细管区带电泳法测定低卡路里食品中甜菊苷 [PDF]

open access: yes, 2002
厦门大学固体表面物理化学国家重点实验室基金资助项
沈明山   +3 more
core  

Electrolyte With Functionalized Boron Nitride Nanosheets for Dendrite‐Free Lithium Metal Anodes

open access: yesRare Metals, EarlyView.
ABSTRACT Lithium metal batteries (LMBs) are regarded as promising candidates for the next‐generation high‐energy‐density storage systems due to their unparalleled theoretical energy density and low redox potential. However, the commercialization of LMBs is tremendously plagued by the barbaric growth of lithium dendrite and the intricate decomposition ...
Ji Zhou   +5 more
wiley   +1 more source

基于节点调度策略的能量有效覆盖算法

open access: yesGuangtongxin yanjiu, 2012
对监测区域进行有效地覆盖以及最大限度延长网络生存周期是无线传感器网络研究的重点课题之一。为此,提出了一种基于节点调度策略的能量有效覆盖算法,该算法通过泊松分布模型构造节点概率密度公式,依照节点密度公式对所关注的目标进行有效覆盖;另一方面,通过节点自身状态调度机制更新以及对邻居节点进行匹配调度的动态转换,使得传感器节点剩余能量与节点消耗能量趋于平衡,从而达到延长网络生存周期。仿真实验结果表明,该算法可实现对监测区域的有效覆盖,同时优化了网络资源的配置,延长了网络生存周期。
孙泽宇, 赵国增
doaj  

管状胃加幽门成形术在52例食管癌切除术中的应用 [PDF]

open access: yes, 2005
目的评估管状胃+幽门成形术在食管癌切除术中的应用价值。方法对52例常规经右胸食管癌切除术中行管状胃加幽门成形术,术后观察胃肠减压量及患者胸胃症状。结果术后胃肠减压量较少。全组吻合口瘘1例(为颈部吻合),胸胃-右支气管瘘并死亡1例;术后明显胸胃无力症状1例,其余病例均无明显胸胃返流及压迫症状;术后短期腹泻6例;术后发生吻合口狭窄4例。其余病例恢复良好。结论经右胸食管癌切除术中行管状胃+幽门成形术,可减轻胸胃潴留所致压迫症状及减少返流,其操作较安全 ...
付成国   +3 more
core  

Dual Synergistic Effects in a Ce‐Modified MnO2/MnO Heterostructure Enabling Outstanding Acidic Oxygen Evolution

open access: yesRare Metals, EarlyView.
ABSTRACT The development of highly efficient and stable nonprecious metal electrocatalysts for the acidic oxygen evolution reaction (OER) is crucial to advance proton exchange membrane (PEM) water electrolysis. In this work, a dual synergistic strategy was proposed by constructing a Ce‐modified MnO2/MnO heterostructure.
Chuanbin Li   +7 more
wiley   +1 more source

A Molten Salt Strategy to Convert Bulk Nb2O5 Into 2D Nonlayered Niobium Nitride Nanosheets for Superior Pseudocapacitive Storage

open access: yesRare Metals, EarlyView.
ABSTRACT Two‐dimensional (2D) nonlayered niobium nitrides have attracted considerable interest for electrochemical energy storage. However, the synthesis of these materials is hampered by their nonlayered crystal structures, which are characterized by strong three‐dimensional chemical bonding.
Rui Huo   +7 more
wiley   +1 more source

Methodologic Study of HPCE Fingerprints of Radix paeoniae Alba and Radix paeoniae Rubra [PDF]

open access: yes, 2008
目的确定赤芍和白芍的高效毛细管电泳分析方法,建立赤芍和白芍的高效毛细管电泳法(HPCE)指纹图谱。方法HPCE工作条件:采用未涂层熔融石英毛细管(内径75μm,有效长度50 cm),分离电压为25 kV,柱温25℃,二极管阵列检测器(DAD)检测波长为220 nm,缓冲液为30 mmol/L硼砂(pH=9.0)溶液。按此条件对来自不同产地的7种赤芍样品和8种白芍样品进行了分析。结果建立了赤芍和白芍HPCE指纹图谱,采用中药指纹图谱相似度计算软件 ...
杨东方   +5 more
core  

Optimizing the Surface Coordination of Pd‐Cu Nanoalloy Through Chemical Ordering to Enhance Hydrogenation Selectivity

open access: yesRare Metals, EarlyView.
ABSTRACT Precise control of chemical ordering in bimetallic nanocatalysts offers a route to decouple activity and selectivity in acetylene hydrogenation, but direct atomic‐scale evidence linking surface order to catalytic performance is scarce. Here, we tune Pd‐Cu nanoalloys from chemically disordered to highly ordered states by composition control and
Fan Xue   +5 more
wiley   +1 more source

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