极间距对车用MAO层组织结构及耐蚀性的影响

在硅酸盐电解液体系中用不同极间距制备汽车用镁合金表面微弧氧化(MAO)层.对比不同极间距(40、120、200、280、360 mm)的涂层微观结构,设计电化学试验,分析极间距对涂层耐蚀性的影响.结果表明:将极间距增至200 mm,涂层表面平整,微孔较小,且均匀分布,缺陷数量低,致密度更高.MAO层由内部致密层与外部疏松层构成,致密层和基体结合层厚度较小.以不同极间距制备的涂层元素与物相成分基本一致.增大极间距后,涂层厚度降低,正面涂层厚度比反面大,在距离达到200 mm前,正反面涂层厚度相近.当距离达到200 mm时,腐蚀电流密度最小,涂层耐蚀性最优,涂层耐蚀能力可通过设定极间距调节.     

氮含量对HPD-1双相不锈钢组织及力学性能的影响

通过显微组织观察与力学性能测试研究了氮含量(0.08%~0.22％,质量分数)对HPD-1双相不锈钢硬度、拉伸性能、低温冲击性能及疲劳性能的影响。结果表明,氮含量变化可显著影响试验钢γ/α相比例,当氮含量由0.08％升高到0.22％,γ相含量由38.1％提高至56.5％。α相的硬度由273 HV10提高到343 HV10,γ相的硬度由238 HV10提高到299 HV10,试验钢强度明显提升。氮元素对两相比例和奥氏体相韧性的双重影响导致试验钢低温冲击性能呈先上升后下降的趋势;更高的氮含量抑制疲劳裂纹萌生与拓展,是影响HPD-1双相不锈钢室温疲劳性能的主要因素。撕裂棱是疲劳断口的显著特征。     

基于光流法的固体内部声传播方向测量

目前采用光弹设备测量超声传播方向多为人眼主观观测,其误差较大,难以实现精确的定量测量。将Farneback光流法应用于光弹图像的处理,并根据帧与帧之间的光流图来计算光弹图像中的超声传播方向,可以捕捉图像中的动态声场。在实验中对不同传播方向的超声进行了测量,其绝对偏差度数最大值为2.85°,测量结果较为准确。因此,Farneback光流法可用于光弹图像中声波传播方向的判断,且具有快速、准确和直观等特点。     

基于混合蚁群算法的异质车队低碳VRP研究

针对货运车辆在配送调度过程中产生大量碳排放的问题，建立模型将多种影响碳排放量的因素协同优化。模型中考虑了不同载重量的异质车队，两个节点之间有多条道路的柔性路径，以及车辆重量随卸货而减少的动态负载等因素，以碳排放量、行驶时间和行驶路程为优化目标，并加入了节点需求时间窗、根据速度变化划分路段、交接和卸货时间的约束。提出了一种混合蚁群算法，利用蚁群算法信息素强度更新方式保持群体记忆性，利用粒子群算法的快速收敛特性增加计算效率。通过随机数值算例的仿真优化与对比分析，验证了算法和模型的有效性。     

An efficient method of generating vortex electromagnetic wave based on double‐layer transmissive metasurface

A broadband double‐layer transmissive metasurface (TMS) for effective generate vortex electromagnetic wave is presented in this paper. The proposed TMS consists of two types of elements. The first element is composed of a multi‐resonant dipole and four metal vias. The metal vias increase the coupling strength between the upper and lower layers to improve transmission efficiency. On the basis of the first element, the second element adds stubs to ensure sufficient phase shift. The far‐field cross polarisation is eliminated by special element arrangement. Then, a centre‐fed linear polarisation TMS is designed to generate orbital angular momentum beams with mode l = ? 1. The proposed TMS is designed, manufactured and measured to verify the proposed design. The measured results indicate that a maximum gain of 20.8 dBi and narrow divergence angle of ±5° are achieved at 18 GHz. Furthermore, mode purity is higher than 86.1% within the 17 to 19 GHz band. The proposed double‐layer TMS saved costs, reduced weight and without assembly error is a good candidate for OAM generator.     

基于广义深度学习的含DG配网故障诊断方法

针对传统故障定位方法难以满足含分布式电源配电网的问题，提出一种基于广义深度学习的故障定位方法。利用广义深度学习在逼近能力和容错性方面的优势，挖掘响应数据与故障位置之间的映射关系，建立含分布式电源配电网故障定位的模型。IEEE34节点仿真结果表明，该方法可有效实现含分布式电源配电网的故障定位，准确率高，速度快，且在信息畸变或缺失时容错性好。     

Hollow mesoporous silica nanoparticles as nanocarriers employed in cancer therapy: A review

Hollow mesoporous silica nanoparticles (HMSNs) have become an attractive drug carrier because of their unique characteristics including stable physicochemical properties, large specific surface area and facile functionalization, especially made into intelligent drug delivery systems (DDSs) for cancer therapy. HMSNs are employed to transport traditional anti-tumor drugs, which can solve the problems of drugs with instability, poor solubility and lack of recognition, etc., while significantly improving the anti-tumor effect. And an unexpected good result will be obtained by combining functional molecules and metal species with HMSNs for cancer diagnosis and treatment. Actually, HMSNs-based DDSs have developed relatively mature in recent years. This review briefly describes how to successfully prepare an ordinary HMSNs-based DDS, as well as its degradation, different stimuli-responses, targets and combination therapy. These versatile intelligent nanoparticles show great potential in clinical aspects.     

表面润湿性对梯形除雾器分离性能的影响

为解决实际工业中除雾器在高气速时分离效率明显降低的问题，利用除雾器分离实验装置，以水为实验介质，采用电火花线切割技术在叶片表面构建仿生微结构实现表面疏水化，考察了表面润湿性对除雾器分离效率和压降的影响。结果表明，仿生微结构的疏水功能和减阻效应良好，表面液膜的排液速率明显加快。当气速超过5 m/s时，其液膜厚度相对较薄，可有效抑制液滴的二次夹带，提升分离效率。同时，疏水型梯形除雾器内的流场分布较平缓，流动阻力小，总压降约为带钩型梯形除雾器的一半。因此，疏水型梯形除雾器兼具高效率和低阻力特性，综合分离性能最佳。