17-4PH不锈钢纳米析出物的磁小角中子散射研究

本文充分发挥中子对磁灵敏、穿透力强等技术优势,利用加载磁场小角中子散射实验技术研究核电站实际服役14年的阀杆17 4PH不锈钢样品。结果表明,与不加磁场时相比,加载磁场条件下二维散射图谱呈明显各向异性,在散射矢量垂直于磁场方向上散射强度显著增强。利用多分散球模型对数据进行拟合,结合原子探针实验结果分析得出,衬度的增加降低了Cu析出物周围元素分布不均匀对散射的相对贡献,从而有助于更加准确地获得Cu纳米析出物的尺寸。     

Mastering Surface Reconstruction of Metastable Spinel Oxides for Better Water Oxidation

Developing highly active electrocatalysts for oxygen evolution reaction (OER) is critical for the effectiveness of water splitting. Low‐cost spinel oxides have attracted increasing interest as alternatives to noble metal–based OER catalysts. A rational design of spinel catalysts can be guided by studying the structural/elemental properties that determine the reaction mechanism and activity. Here, using density functional theory (DFT) calculations, it is found that the relative position of O p‐band and M_Oh (Co and Ni in octahedron) d‐band center in ZnCo_2?xNi_xO₄ (x = 0–2) correlates with its stability as well as the possibility for lattice oxygen to participate in OER. Therefore, it is testified by synthesizing ZnCo_2?xNi_xO₄ spinel oxides, investigating their OER performance and surface evolution. Stable ZnCo_2?xNi_xO₄ (x = 0–0.4) follows adsorbate evolving mechanism under OER conditions. Lattice oxygen participates in the OER of metastable ZnCo_2?xNi_xO₄ (x = 0.6, 0.8) which gives rise to continuously formed oxyhydroxide as surface‐active species and consequently enhances activity. ZnCo_1.2Ni_0.8O₄ exhibits performance superior to the benchmarked IrO₂. This work illuminates the design of highly active metastable spinel electrocatalysts through the prediction of the reaction mechanism and OER activity by determining the relative positions of the O p‐band and the M_Oh d‐band center.     

雷达图分析法在烤烟品种试验中的应用

应用"雷达图"分析法,综合考虑多个性状值及协调性,根据7个区域试验品种(系)在诸城试验点的叶数、单叶重、产量、均价、上等烟比例、烟碱、还原糖、钾含量等多个指标对参试品种进行综合评价。结果表明,参试品种中,CF212、CF202表现最好,9803、LJ935、Y8303、Y017次之,NC89表现最差。评价结果与品种实际表现吻合,用"雷达图"分析法对试验品种进行综合评价是可行的。     

基于UDP的被动式可靠报文传输协议研究

针对卫星网环境下报文传输要求可靠高效的实际需求,设计一种新型协议PUDP(Passive UDP)。该协议通过在传统TCP/IP协议的UPD层和应用层中间加入一层可靠UDP模块,保证数据的可靠传输,实现了基于UDP报文传输的可靠传输。同时该协议还将应用层的一部分数据包传输控制机制糅合到流量控制当中,由报文接收端也就是客户端控制整个报文传输过程,实现了报文被动式传输,减轻了服务器端的工作负担。通过测试证明,该协议较好地解决了卫星网环境下报文传输可靠高效的问题。     

金属注射成形粘结剂的研究进展

本文阐述了金属注射成形粘结剂体系的设计，粘结剂脱除技术的发展过程和它们对烧结后产品力学性能的影响。改善粘结剂体系和研究合理的脱脂技术是金属注射成形技术成功的关键。     

长壁综采工作面采煤机定位定姿技术研究

分析了现有的采煤机支架传感定位技术、轨道里程计定位技术、自主定位技术的研究现状及其存在的问题;提出了以采区绝对坐标为参考坐标,采煤机在开采煤层内绝对定位的研究内容;探讨了采煤机定位技术在长壁综采工作面自动化中的作用。     

一种计及光伏发电功率不确定性的实时调度方法

大规模光伏发电注入电力系统,其功率的不确定性给实时调度带来了挑战,进而对光伏发电功率和负荷预测的精度提出了更高的要求。针对此问题,文章提出一种计及光伏发电功率不确定性的实时调度方法。首先,基于实时调度的有效稳态安全区域法和线性潮流模型,提出一种计及电压幅值的实时调度模型;其次,通过鲁棒优化等方式将原问题转化为确定性的线性规划问题求解;然后,根据所提方法,分析光伏发电功率和负荷预测精度对于电力系统实时调度安全性和经济性的影响;最后,通过改进IEEE 9节点系统和IEEE 118节点系统进行算例分析,说明所提方法的有效性和高效性。     

Poly(Butylene Terephthalate) Filled with Sb2O3 Nanoparticles: Effects of Particle Surface Treatment,Particle Size,Particle Morphology and Particle Loading on Mechanical Properties of Composites

Abstract

Poor dispersion of nanoparticles in polymer matrix would limit the development and application of particulate-filled polymer composites. Therefore, the Sb₂O₃ nanoparticles were functionalized by a combination of cetyltrimethyl ammonium bromide (CTAB) and silane coupling agent KH-560 via water bath modification method so as to improve the dispersion of Sb₂O₃ nanoparticles in poly(butylene terephthalate) (PBT) matrix and enhance the interfacial adhesion between nanoparticles and polymer matrix. Besides, the coating efficiency of compound modifiers on the surface of Sb₂O₃ nanoparticles was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA). The Sb₂O₃ nanoparticles with different morphologies were systemically measured using transmission electron microscopy and dynamic light scattering measurement. The effects of particle surface treatment, particle size, particle morphology and particle loading on mechanical properties of composites were studied by the X-ray diffraction (XRD), tensile test machine and impact strength machine. The tensile strength of nanocomposites gradually increases with decreasing the particle size at the same amount of Sb₂O₃ nanoparticle fillers, which is attributed to improvement of interfacial contact area and stronger interfacial adhesion between Sb₂O₃ nanoparticles and PBT matrix. And the compound modified Sb₂O₃ nanoparticles are homogeneously dispersed in PBT matrix and play an important role in the properties enhancement. Moreover, taking consideration of the tensile and impact strengths, the optimal loading is 3?wt%.     

基于ZigBee网络的室内甲醛浓度远程实时监测系统设计

针对现有家用甲醛检测手段中存在的测量点单一,无法远程监测的问题,设计了一种基于无线传感器网络ZigBee的室内甲醛浓度远程实时监测系统,给出了整体系统的构建方案,构建了甲醛浓度检测的无线传感网络,通过ZigBee网络实现对家庭空间中多个测量点的实时采集,经过网络远传后通过LabVIEW监测程序实现数据的远程实时显示。经过测试,完成了对家庭环境中多个测量点的室内甲醛浓度的远程实时监测,验证了系统的可行性与可靠性。     

船舶轨迹异常检测方法研究进展

近年来,异常检测技术在分析和利用船舶轨迹数据中扮演着越来越重要的角色,已经成为航海领域的一个热点研究方向。船舶轨迹的异常检测旨在利用相关的异常检测算法,研究船舶个体或群体的行为特征,发现隐藏在其中的船舶异常行为模式或船位。主要从船舶位置和行为方面分析了船舶异常行为的概念和分类,综述了船舶轨迹异常检测的方法,评述了各方法在船舶轨迹异常检测中应用的优点和不足,讨论了船舶轨迹异常检测存在的问题和面临的挑战。