电激励连续波HF/DF激光器放电参数的优化

放电管作为电激励连续波HF/DF激光器的F原子发生器,在整个激光器系统中占有重要地位。目前流行采用的是高压直流电源加镇流电阻的放电模式,典型电参数为接近10kV高电压、百毫安量级的低电流。传统理论和实验结果均认为:放电管F原子产率与放电管注入功率成正比,从而激光器输出功率也应与之成正比。引入不同阻值的镇流电阻,发现对于相同的注入功率,低电压、大电流模式比高电压、小电流模式更容易获得高的功率输出。     

Ionic Modulation of Interfacial Magnetism in Light Metal/Ferromagnetic Insulator Layered Nanostructures

Ferromagnetic insulator thin film nanostructures are becoming the key component of the state‐of‐the‐art spintronic devices, for instance, yttrium iron garnet (YIG) with low damping, high Curie temperature, and high resistivity is explored into many spin–orbit interactions related spintronic devices. Voltage modulation of YIG, with great practical/theoretical significance, thus can be widely applied in various YIG‐based spintronics effects. Nevertheless, to manipulate ferromagnetism of YIG through electric field (E‐field), instead of current, in an energy efficient manner is essentially challenging. Here, a YIG/Cu/Pt layered nanostructure with a weak spin–orbit coupling interaction is fabricated, and then the interfacial magnetism of the Cu and YIG is modified via ionic liquid gating method significantly. A record‐high E‐field‐induced ferromagnetic resonance field shift of 1400 Oe is achieved in YIG (17 nm)/Cu (5 nm)/Pt (3 nm)/ionic liquid/Au capacitor layered nanostructures with a small voltage bias of 4.5 V. The giant magnetoelectric tunability comes from voltage‐induced extra ferromagnetic ordering in Cu layer, confirmed by the first‐principle calculation. This E‐field modulation of interfacial magnetism between light metal and magnetic isolator may open a door toward compact, high‐performance, and energy‐efficient spintronic devices.     

色散缓变光纤中Raman孤子自频移效应的研究

利用绝热扰动法研究了色散缓变光纤中Ｒａｍａｎ孤子自频移效应，得到了色散缓变光纤中Ｒａｍａｎ孤子自频移的表达式。结果表明：光纤色散变化率存在一个可以有效抑制孤子自频移的阈值，当光纤色散变化率大于这个阈值时，色散缓变光纤可以抑制孤子自频移，而当光纤色散变化率小于这个阈值时，色散缓变光纤不仅不能抑制孤子自频移，反而加剧孤子自频移。     

Rolling Friction Enhanced Free‐Standing Triboelectric Nanogenerators and their Applications in Self‐Powered Electrochemical Recovery Systems

Heavy metals contained in wastewater are one of the most serious pollutions in natural resources. A self‐powered electrochemical recovery system for collecting Cu ions in wastewater by incorporating a rolling friction enhanced freestanding triboelectric nanogenerator (RF‐TENG) is developed here. The RF‐TENG utilizes integrated cylindrical surfaces using the conjunction of rolling electrification and freestanding electrostatic induction, which shows outstanding output performance and ultrarobust stability. By using the kinetic energy of flowing water, a collection efficiency of up to 80% for Cu²⁺ ions in wastewater has been achieved. Self‐powered electrochemical systems are one of the most promising applications of TENGs for independent and sustainable driving of electrochemical reactions without the need for any additional power supply. This research is a substantial advancement towards the practical applications of triboelectric nanogenerators and self‐powered electrochemical systems.     

基于DeepLabV3+与注意力机制相结合的图像语义分割

基于DeepLabV3+进行图像分割时,在特征提取阶段忽略了不同级别的特征图中存在的特征重要程度不同,丢失了大量的细节信息,致使分割效果不佳.针对该问题,提出了一种基于DeepLabV3+与注意力机制相结合的图像语义分割算法.在骨干网络Xception模型中提取两条低级特征作为解码器的输入特征,提高特征提取的准确性;采...     

变电运行动态培训仿真系统的研制

本文重要介绍用于电气运行人员培训的动态仿真专家系统的设计思想、实现方法及其应用效果。     

气相生长氮化铝单晶的新方法

通过在钨坩埚盖开小孔的方法改变氮化铝结晶衬底上的温度场分布,在开孔处形成局部低温区;由于孔的几何尺寸的限制和氮化铝晶体生长的各向异性,开孔处的氮化铝晶体单晶化;随后,开孔处的单晶起籽晶的作用,逐渐长成较大尺寸、较高质量的氮化铝单晶.目前用该方法已经制备出直径大于2mm的氮化铝单晶体.     

高速局域网技术的发展

对近年来出现的几种高速局域网技术，如快速以太网、千兆以太网、交换式以太网等作了详细的介绍。     

基于弯曲板波的延迟线振荡器的ANSYS仿真

针对复合板结构中弯曲板波谐振频率计算相对复杂的问题,建立并分析了基于弯曲板波延迟线振荡器的理论模型,计算得到A0(0阶反对称)模式板波的谐振频率为41 MHz;为了验证理论分析的结果,利用有限元软件ANSYS建立了基于弯曲板波的延迟线振荡器的3D有限元模型,并对其进行了谐响应分析以及瞬态动力学分析。谐响应分析得到A0模式的谐振频率为37.2 MHz,与理论计算结果的相对误差为9.3%;瞬态动力学分析得到A0模式的谐振频率为39.1 MHz,与理论计算结果的相对误差为4.6%。计算和仿真为基于弯曲板波的延迟线振荡器的结构设计提供了重要的依据。     

通信光纤偏振模色散的在线测试-干涉法及其应用

重点讨论了干涉法测试单模光纤偏振模色散 ( PMD)的原理、方法 ,并对长飞光纤光缆有限公司生产的 G.65 2、G.65 5单模光纤进行了在线测试 ,根据测试数据 ,分别计算出了这两种光纤 PMD的链路值 .结果表明 ,长飞光纤光缆有限公司生产的这两种光纤的 PMD值均在标准范围之内