软锰矿的微波干燥特性研究

微波加热技术作为一种新型的干燥技术,在矿物干燥领域具有广泛的应用。本论文以广西大新县软锰矿作为微波干燥的研究对象,以微波加热作为干燥热源,分别在不同的软锰矿初始含水率、软锰矿质量、微波功率条件下进行了软锰矿的微波干燥实验,研究实验因素对软锰矿微波干燥速率等的影响规律,并以此研发出微波干燥软锰矿新工艺,并为微波干燥软锰矿的工业应用提供理论基础和实验数据。     

Synthesis,structure and luminescence of a high-purity and thermal-stable Sr9LiMg(PO4)7: Eu3+ red phosphor

Eu³⁺-activated Sr₉LiMg(PO₄)₇ phosphors, which presented bright red emissions mainly from the ⁵D₀→⁷F₂ transition of Eu³⁺ ions upon the near-ultraviolet excitation, were successfully synthesized in ambient atmosphere. The crystal structure, phase constitution, photoluminescent behaviors, decay time, internal quantum efficiency and thermal stability of the resultant phosphors were investigated in detail. Eu³⁺ ions are found to tend to occupy multiple Sr²⁺ sites, which are 7, 8 and 10-coordinated. The optimal doping concentration is 7 mol% and the electrical multipolar interaction contributed to the non-radiative energy transfer between Eu³⁺ ions in Sr₉LiMg(PO₄)₇ host lattices. Temperature-dependent PL spectra indicated Sr₉LiMg(PO₄)₇: Eu³⁺ possess excellent emission and color stability at elevated temperature. Fabricated single-chromatic LED prototype emit bright red light under 20 mA bias current, which demonstrates that Sr₉LiMg(PO₄)₇: Eu³⁺ phosphor is of great potential as converted phosphor in NUV LED application.     

计及可靠性成本的风光储微电网储能容量协同优化

对比常规能源,新能源具备可再生、污染低、资源丰富的优势,其中风光发电被大规模引入到微电网系统,但由于其发电量具有较强的不确定性,这使得如何提高新能源消纳水平、提升电力系统运行稳定性以及降低微电网配置成本成为了充满挑战性的重要问题。针对上述问题,文章提出一种计及可靠性成本,同时考虑风、光资源多时间尺度不确定性的风光储互补微电网系统储能容量协同优化的方法。该方法采用自回归滑动平均模型和Homer软件仿真离散的风速、光辐照度序列,构建出风机、光伏发电机的出力模型;采取电量不足期望值为评估指标建立可靠性成本函数,构建出微电网配置成本模型;使用改进二阶振荡粒子群算法求解系统最优配置成本。算例结果表明了该方法的可行性及经济性,可为实际风光储互补微电网系统配置规划提供参考。     

一种改进的工业微波炉加热控制PID技术

讨论了一种基于共轭梯度算法的改进的BP神经网络的PID控制技术,利用神经网络的自学习能力,实现对工业微波加热炉中温度的智能控制,用于解决微波加热系统的时变性,不确定性和非线性方面的问题。仿真结果表明这种建立在神经网络模型上的PID控制技术能够满足工业微波加热中的温度控制要求。     

Micromechanical properties and microstructure evolution of magnesia partially stabilized zirconia prepared by spark plasma sintering

Magnesia partially stabilized zirconia (Mg-PSZ) is a widely used engineering ceramic owing to its high hardness and exceptional toughness. It is usually processed by conventional firing followed by subeutectoid aging. In this work, Mg-PSZ was prepared by spark plasma sintering (SPS) followed by sequential subeutectoid aging to fine-tune its mechanical properties. Mg-PSZ prepared by SPS with the rapid heating capability presents much smaller grains than conventionally prepared counterparts. After aging, a significant fraction of the matrix cubic phase transforms into tetragonal, orthorhombic, and monoclinic zirconia. Microindentation and in-situ microcompression tests reveal that aging Mg-PSZ for 4 h leads to maximum fracture toughness and fracture strain due to the tetragonal-to-monoclinic transformation toughening. Post compression TEM analyses show dominant monoclinic ZrO₂ decorated by a high density of twin boundaries and stacking faults formed to accommodate the shear deformation. Preparation of Mg-PSZ by SPS offers rapid and effective approaches in finetuning the phases and mechanical properties.     

外场强化技术在锰矿资源处理过程中的研究进展

摘要：锰矿作为一种重要的战略性资源矿产,广泛应用于钢铁、电池、农业、冶金及国防工业等领域,发挥着至关重要的战略作用。近年来,随着锰矿产业的迅速发展,中国已经成为全球第一大锰矿资源消费国,锰矿资源需求量逐年增加。基于当前锰矿仍为我国短缺矿产、需求量大,传统加工工艺在产率、可持续发展和自动化等方面出现了明显短板的实际情况,为了保障国家锰矿资源战略安全,促进我国锰矿行业的可持续发展,因此探索一种能高效、清洁、经济处理锰矿的加工方法成为国内外研究热点。研究表明,微波、超声波、流场、压力场等外场手段能高效清洁的处理矿物,并提高产品质量。因此,对微波、超声波、电场、压力场及流场等外场强化技术在锰矿处理过程中的应用研究做出了总结和思考,这对外场强化技术处理矿产资源的后续研究具有指导意义。     

响应曲面法优化硫酸浸出钒钛磁铁矿电炉渣试验研究

攀枝花地区一半左右的钛以钒钛磁铁矿形式存在,在选矿时进入到铁精矿中,通过高炉炼铁成为电炉渣,其中的钛难以回收利用,造成了钛资源的浪费和环境污染。为提取电炉渣中的钛,基于响应曲面法系统研究了浸出温度、酸矿比、硫酸浓度3个工艺参数及其交互作用对电炉渣的钛浸出率的影响,并建立了钛浸出率与工艺参数间的数学模型。通过对模型的分析,各工艺参数对钛浸出率影响大小为：酸矿比（B）＞温度（A）＞硫酸浓度（C）,在浸出温度为245.58℃,酸矿比为2.15,硫酸浓度为90.94%条件下,电炉渣中钛的浸出率为96.14%。     

基于HDP的主题词向量构造——以柬语为例

针对单一词向量中存在的一词多义和一义多词的问题，以柬语为例提出了一种基于HDP主题模型的主题词向量的构造方法。在单一词向量基础上融入了主题信息，首先通过HDP主题模型得到单词主题标签，然后将其视为伪单词与单词一起输入Skip-Gram模型，同时训练出主题向量和词向量，最后将文本主题信息的主题向量与单词训练后得到的词向量进行级联，获得文本中每个词的主题词向量。与未融入主题信息的词向量模型相比，该方法在单词相似度和文本分类方面均取得了更好的效果，获取的主题词向量具有更多的语义信息。     

New Stochastic Stability Criteria for Nonlinear Neutral Markovian Jump Systems

International Journal of Control, Automation and Systems - This paper address the stochastic stability of neutral markovian jumping systems with nonlinear perturbations. By constructing novel...