摘要：通过研究可调谐滤波器的基本原理,提出了一种奇、偶模频率分别可控的双模谐振器,采用砷化镓变容二极管作为调谐元器件,实现了高温超导带通滤波器的连续可调谐。基于全波电磁仿真分析方法,在YBCO/MgO基片上成功设计、制作了四节高温超导可调滤波器。测试结果表明,该滤波器的可调频率范围为1.296~1.526 GHz(16.3%),验证了该设计方法的有效性。

摘要：研究了具有陷波特性的超宽带超导滤波器设计方法,采用两级多模谐振器实现了具有超宽带通带的超导滤波器,具有带内插损低、带边陡峭度高、结构紧凑的优点。为了抑制通带内不需要的干扰信号,采用开路短截线的方法成功引入一个中心频率为5GHz的阻带。未经调谐的测试结果和仿真结果吻合得很好,3-dB带宽从3.28GHz到10.56GHz,相对带宽为105.2%。超宽带通带内引入的阻带具有高的选择性(3-dB带宽小于5%)和高的抑制度(高于60dB)。此外,通带反射系数高于14.2dB。

摘要：该文提出一种基于非线性仿射的风电场电压实时计算和优化方法。首先,以网损和并网电压波动综合最小为目标,建立风电场多时段动态无功优化模型,利用半不变量法分析风电功率不确定性对机端电压的影响,采用改进内点法实现模型的高效求解;其次,提出一种非线性仿射方法,快速准确地获得计及风电功率波动后的系统电压状态,并通过计算风机无功调节量来实现系统电压实时优化;再次,设计考虑风电功率对机端电压和并网电压综合影响的事件触发算法,降低风电功率波动平缓时风机的无功控制频率;最后,在我国某实际风电场的仿真试验表明,非线性仿射法能够快速获得系统实时电压状态,电压实时优化方法能够有效地防止机端电压越限并减小并网电压波动。

摘要：The driving force for using powder metallurgy(PM)mostly relies on its near net-shape ability and cost-performance *** automotive application is a main market of PM industry,requiring parts with competitive mechanical or functional performance in a mass production *** the automobile technology transforms from traditional internal combustion engine vehicles to new energy vehicles,PM technology is undergoing significant changes in manufacturing and materials *** review outlines the challenges and opportunities generated by the changes in the automotive technology for ***-cost,high-performance and light-weight are critical aspects for future PM materials ***,the studies on PM lean-alloyed steel,aluminum alloys,and titanium alloy materials were *** addition,PM soft magnetic composite applied to new energy vehicles was *** new opportunities for advanced processing,such as metal injection molding(MIM)and additive manufacturing(AM),in automotive industry were *** general,the change in automotive industry raises sufficient development space for ***,emerging technologies require more preeminent PM ***-based parts are still the main PM products due to their mechanical performance and low *** will occupy the growing market of highly flexible and complex *** opens a door for fast prototyping,great flexibility and customizing at low cost,driving weight and assembling reduction.

摘要：构建矿区开采沉陷盆地对研究地表变形特征和破坏机理具有重要意义。目前采用机载激光雷达(light detection and ranging,LiDAR)点云构建沉陷盆地的方法尚处于探索阶段。针对山区沉陷盆地受植被和地形影响大的特点,通过分析坡度变率因子和点云植被密度对沉陷盆地精度的影响,提出基于滑动窗口的粗差点滤波方法,后采用小波方法进行高频误差的滤除,并通过样本统计的方法确定沉陷盆地的边界,最终构建高精度的沉陷盆地。结果表明:通过组合滤波方法,沉陷盆地中误差从0.195 m降至0.072 m,最大误差从1.342 m降至0.245 m,为山区沉陷盆地的构建提供了新方法。