Results 21 to 30 of about 1,260,379 (169)
Dianci bileiqi, 2022 作为重要的过电压防护元件,ZnO压敏电阻片的性能也需要不断提高。对ZnO压敏电阻片制备工艺中聚乙烯醇(PVA)的影响进行了研究。通过对比不同PVA种类及含量对造粒的影响后发现,选用的PVA聚合度越高,烧结陶瓷的晶粒尺寸就越小;PVA的添加量越多,晶粒尺寸也越小;其次PVA的聚合度会影响到压敏陶瓷的晶界电阻和击穿场强,它们之间成正相关的趋势,但是过量添加PVA会导致其晶界电阻活化能减小,压敏特性降低,导致泄漏电流密度增大;采用低聚合度的PVA会改善电气性能,即提升其压敏特性并降低泄漏电流密度;造粒过程中 ...
张兆华 +9 more
doaj
Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT Electromagnetic wave absorption materials require high dielectric loss and excellent impedance matching performance. However, current conventional biomass‐derived electromagnetic wave absorption materials are still limited by low electrical conductivity and a single structure.
Yue Zhang +9 more
wiley +1 more source
Gongye shui chuli, 2008 不同聚合度的聚乙二醇单甲醚丙烯酸酯分别与丙烯酸(AA)在水溶液中聚合,得到两种聚醚型共聚物阻垢剂T-400和T-1000。考察了阻垢剂用量、钙离子浓度、溶液pH,以及温度、时间对其阻磷酸钙垢率的影响,并与其他阻垢剂进行了比较。结果表明,聚醚型阻垢剂具有优异的阻磷酸钙垢的性能,对钙离子容忍度较高,受温度影响较小,可用于高pH的水系统中,并长时间有效;聚醚侧基的聚合度大小对其阻磷酸钙垢性能影响不大。
孙绪兵, 罗玉梅, 梁兵
doaj
Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT Dielectric polymers commonly suffer from severe performance degradation above 150°C, hindering advanced power systems. Herein, we demonstrate a polyetherimide (PEI) nanocomposite that overcomes this by mimicking the gradient architecture of nacre and bamboo, incorporating a continuous vertical gradient of fluorinated boron nitride nanosheets ...
Jian Wang +8 more
wiley +1 more source
Gaoya dianqi, 2020 对油中纸绝缘材料在不同温度条件下进行加速热老化试验,以绝缘纸聚合度作为诊断纸绝缘老化程度的标准,采用蒽酮比色法测量了老化油样中的总糖含量,探究油中总糖、糠醛与聚合度的相关性关系。研究表明:聚合度在1 000～600范围内对应的油样中的总糖含量均随着聚合度降低而逐渐增大且总糖含量比糠醛含量变化更显著,故在老化前中期阶段,油中总糖可作为新的特征量来表征油纸绝缘老化程度;聚合度在600～200范围内对应的油样中总糖含量未呈现出统一的变化规律,故在老化中后期阶段,总糖无法用来表征油纸绝缘老化程度 ...
付强 +4 more
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Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT The poor soft tissue integration around titanium implants creates a microgap that serves as a pathway for pathogen invasion, resulting in infection, inflammation, and the progression of peri‐implantitis. As the implant’s transmucosal component, the abutment determines the degree of peri‐implant soft tissue attachment.
Xuan Li +7 more
wiley +1 more source
Gongye shui chuli, 2019 以铝箔酸洗废液为原料，通过酸溶-碱化-水解熟化工序制备聚合硫酸铁铝（PAFS）。用XRD、SEM对产品结构进行表征，并进行净水实验。实验结果表明，在酸浓度为9 mol/L、n（Fe3+）：n（Al3+）为4：1、反应温度为110℃、反应时间为4.5 h、碱化度0.6、水解温度为70℃、水解时间4 h、熟化温度为50℃、熟化时间8 h的条件下，制备的聚合硫酸铁铝液体产品呈无定型、多晶体矿混合聚合物结构。污水净化结果表明，除浊率与现有聚合硫酸铁（PFS）的效果相当 ...
张骁 +7 more
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Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT Through grain boundary segregation engineering, a crack‐free high‐strength CoCrNi medium‐entropy alloy (MEA) can be successfully fabricated via laser powder bed fusion (PBF‐LB). The influence of micron‐sized TiC particles on microstructural evolution, grain boundary segregation behavior, and mechanical properties was systematically ...
Cunliang Pan +9 more
wiley +1 more source
Gongye shui chuli, 2012 以马来酸酐(MA)与氨水为原料热缩聚法合成聚天冬氨酸阻垢剂,分别考察了原料配比、热缩聚温度和热缩聚时间对产物的阻垢性能的影响,得到最佳合成条件:n(MA)∶n(NH3)为1∶2.0,热缩聚温度240℃,热缩聚时间3h。当实验水中Ca2+质量浓度为240mg/L时,聚天冬氨酸阻垢剂的阻垢率达到72%,适用于低矿化度的工业循环冷却水和油田回注水。同时使用L-天冬氨酸对聚合物开环改性,其阻垢率可达到87%。
张尔赤 +5 more
doaj
Rare Metals, Volume 45, Issue 6, June 2026.ABSTRACT The urgent environmental crisis caused by polyethylene terephthalate (PET) waste necessitates efficient upcycling strategies. Herein, we establish a novel pathway to transform waste PET plastic into a high‐performance catalytic material for mediating the oxygen evolution reaction (OER). Through a one‐step hydrothermal process, waste PET serves
Xin Wang +5 more
wiley +1 more source