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亲水性两性离子交联聚合物微球的制备及性能 被引量:2
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作者 杜文浩 宋兆辉 +4 位作者 吴鹏伟 陶丹阳 蔡利山 杨召杰 张熙 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2020年第11期1-6,共6页
水分散聚合是制备亲水性交联聚合物微球的新方法。为揭示水分散聚合体系中各组分及反应条件对产物结构与性能的影响规律,分别以硫酸铵水溶液和聚乙二醇水溶液为分散介质,丙烯酰胺、丙烯酸、甲基丙烯酰氧乙基三甲基氯化铵为共聚单体,过... 水分散聚合是制备亲水性交联聚合物微球的新方法。为揭示水分散聚合体系中各组分及反应条件对产物结构与性能的影响规律,分别以硫酸铵水溶液和聚乙二醇水溶液为分散介质,丙烯酰胺、丙烯酸、甲基丙烯酰氧乙基三甲基氯化铵为共聚单体,过硫酸铵/亚硫酸氢钠为引发剂,N,N’-亚甲基双丙烯酰胺复配物为交联剂制备了亲水性两性离子交联聚合物微球,并对产物结构及在钻井液中的性能进行了研究。结果表明,聚合分散介质和反应组分对产物性能影响显著,分散介质为硫酸铵溶液时产物在钻井液中具有强增黏作用和降滤失作用,而以醇水溶液为分散介质制备的聚合物微球在钻井液中无明显增黏效应;随着聚合体系中丙烯酰胺和交联剂加量增加,微球粒径减小,对钻井液的增黏作用增强;增加引发剂加量会导致产物粒径减小,对钻井液的增黏作用下降。在适当条件下制得的聚合物微球可在升温条件下膨胀,对钻井液黏度影响小,热稳定性好,具有明显的封堵强化作用,可用于不稳定地层钻井施工。 展开更多
关键词 聚合物微球 水分散聚合 钻井液 流变性 封堵性能
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UAV-Assisted FSO Communication System with Amplify-and-Forward Protocol under AOA Fluctuations:A Performance Analysis
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作者 Maozhe Xu Guanjun Xu +3 位作者 Youran Dong Weizhi Wang Qinyu Zhang zhaohui song 《China Communications》 SCIE CSCD 2023年第11期111-130,共20页
Free space optical(FSO)communication has recently aroused great interest in academia due to its unique features,such as large transmission band,high data rates,and strong anti-electromagnetic interference.With the aim... Free space optical(FSO)communication has recently aroused great interest in academia due to its unique features,such as large transmission band,high data rates,and strong anti-electromagnetic interference.With the aim of evaluating the performance of an FSO communication system and extending the line-of-sight transmission distance,we propose an unmanned aerial vehicle(UAV)-assisted dual-hop FSO communication system equipped with amplifyand-forward protocol at the relay node.Specifically,we consider impairments of atmospheric absorption,pointing errors,atmospheric turbulence,and link interruptions due to angle-of-arrival fluctuations in the relay system.The Gamma-Gamma and Malaga distributions are used to model the influence of atmospheric turbulence on the source-to-UAV and UAVto-destination links,respectively.We derive closedform expressions of the probability density function(PDF)and cumulative distribution function(CDF)for the proposed communication system,in terms of the Meijer-G function.Based on the precise PDF and CDF,analytical expressions for the outage probability,average bit error rate,and ergodic capacity are proposed with the aid of the extended generalized bivariate Fox’s H function.Finally,we show that there is a match between the analytical results and numerical results,and we analyze the influence of the system and channel parameters on the performance. 展开更多
关键词 amplify-and-forward protocol angle-ofarrival fluctuations FSO communication Malaga distribution UAV relay
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