一种用于汽车防撞雷达的高隔离度阵列天线

本文设计了一种应用于汽车防撞雷达的高隔离度阵列天线。文章首先设计了一款串馈微带阵列天线,包括一个发射天线阵,两个接收天线阵;然后利用EBG的带阻特性,在发射阵列与接收阵列间加载EBG单元,实现了收-发天线阵、收-收天线阵间的高隔离度,进而可以减小天线整体尺寸。

Cu^(2+)对UV-nTiO_(2)光催化降解抗生素的影响研究

Cu^(2+)是环境中常见二价金属离子,但其对光催化降解抗生素废水的影响有待探明。为此,构建UV-nTiO2体系并探究Cu^(2+)共存下三类抗生素(磺胺类抗生素、氯霉素类抗生素及四环素类抗生素)的光催化降解特性。结果表明,Cu^(2+)可显著影响抗生素光催化降解且呈“低浓度促进,高浓度抑制”效应。当Cu^(2+)浓度介于0.001~0.03 mol/L时,抗生素降解半衰期(T_(0.5))可降低15%~90%;当浓度介于0.01~0.1 mol/L时,T_(0.5)可增大1.5~4倍。结果也表明,Cu^(2+)浓度和T_(0.5)之间的关系可通过正弦函数进行表征(R2>0.905),且Cu^(2+)对抗生素光催化降解效率的影响和抗生素的结构特征显著相关(P<0.05)。

Corrosion behavior of B10 copper-nickel alloy beneath a deposit caused by sulfate-reducing bacteria with carbon source starvation in marine environments

Copper-nickel alloys can suffer severe localized corrosion in marine environments containing sulfate-reducing bacteria(SRB),but the effect of SRB on the under-deposit corrosion of copper-nickel alloys is unknown.In this work,the corrosion behavior of B10 copper-nickel alloy beneath a deposit caused by SRB with carbon source starvation in artificial seawater was studied based on electrochemical measurements and surface analysis.Results demonstrate that SRB with an organic carbon starvation can survive in artificial water but most SRB cells have died.The survived SRB cells can attach to the bare and deposit-covered B10 copper-nickel alloy,leading to the corrosion acceleration.Due to the limitation of organic carbon source,the pitting corrosion of B10 copper-nickel alloy caused by SRB is not serious.However,serious pitting corrosion of the deposit-covered B10 copper-nickel alloy can be found both in abiotic and biotic conditions,and the pitting corrosion and uniform corrosion are further accelerated by SRB.There is a galvanic effect between the bare and deposit-covered specimens in the presence of SRB in the early stage but the galvanic effect after 5 d of testing can be neglected due to the low OCP difference values.