烧结工艺对硼泥玻璃陶瓷显微结构和性能的影响

以硼泥为主要原料对制备玻璃陶瓷工艺进行研究,实验中发现烧结温度和烧结时间对析晶相的成分影响较小,但玻璃陶瓷的表面形貌影响较大;当烧结温度高于析晶温度时,对晶体尺寸影响更大;根据不同烧结温度和烧结时间对玻璃陶瓷结构影响,找出适合的最佳烧结温度和烧结时间,其值为781℃,时间为4h。     

单幅图像刚体目标姿态估计方法综述

刚体目标姿态作为计算机视觉技术的重点研究方向之一,旨在确定场景中3维目标的位置平移和方位旋转等多个自由度,越来越多地应用在工业机械臂操控、空间在轨服务、自动驾驶和现实增强等领域。本文对基于单幅图像的刚体目标姿态过程、方法分类及其现存问题进行了整体综述。通过利用单幅刚体目标图像实现多自由度姿态估计的各类方法进行总结、分类及比较,重点论述了姿态估计的一般过程、估计方法的演进和划分、常用数据集及评估准则、研究现状与展望。目前,多自由度刚体目标姿态估计方法主要针对单一特定应用场景具有较好的效果,还没有通用于复合场景的方法,且现有方法在面对多种光照条件、杂乱遮挡场景、旋转对称和类间相似性目标时,估计精度和效率下降显著。结合现存问题及当前深度学习技术的助推影响,从场景级多目标推理、自监督学习方法、前端检测网络、轻量高效的网络设计、多信息融合姿态估计框架和图像数据表征空间等6个方面对该领域的发展趋势进行预测和展望。     

Al2O3对CaO-Al2O3-SiO2-Na2O系微晶玻璃结构与性能的影响

利用烧结法工艺制备CaO—Al2O3-SiO2-Na2O系微晶玻璃，通过DTA、XRD、IR和SEM等分析手段，系统研究Al2O3对CaO-Al2O3-SiO2-Na2O系微晶玻璃的结晶温度、晶体结构以及性能的影响。研究表明：随着Al2O3质量分数升高，初始析晶温度升高，晶体尺寸增大、析晶率升高，微晶玻璃的表观体积密度、显微硬度和抗折强度呈先增加后降低的趋势。在本实验条件下，最佳的Al2O3质量分数为11．77％。     

溶剂热结晶法制备纳米氧化铁的工艺研究

采用溶剂热结晶法制备工艺，以硫酸亚铁（FeSO4）为原料，聚乙二醇为溶剂，NH3H2O为沉淀剂，制备纳米氧化铁。然后利用XRD和SEM等分析手段，对样品进行表征，研究结果如下：当pH由6升高到10时，反应时间由90min可以缩短到30min，氧化铁的晶体形态从粒状逐渐向片状晶过渡，颜色加深：当反应温度由140℃升高到170℃时，反应时间由90min缩短到45min，晶体的平均粒度由50nm增加到800nm，均匀性降低，晶体形态由球晶向针状晶过渡，颜色逐渐变红。在本实验条件下，最佳的pH=7，最佳的水热温度为160℃，最佳的水热时间为60min。     

树叶状Co和Co3O4的水热合成与磁性研究

以氯化钴（CoCl2·6H2O）和氢氧化钠作为反应前驱物,采用水热法合成微米级树叶状钴单质,在500℃退火条件下得到形貌相似的Co3O4粒子,并运用XRD、SEM和VSM对所得粒子的结构、形貌和磁性能进行了初步研究。结果表明,树叶状钴单质表现出室温铁磁行为,具有较高的磁参数,其中饱和磁化强度为139．3emu／g、矫顽力为29．5kA／m。同时发现,在500℃×1h退火后的CosOa还出现极弱的铁磁性行为,可能是未完全氧化的Co单质所产生。     

Effects of Rare Earth Oxide on Viscosity of Mold Fluxes for Continuous Casting

The effects of RE (rare earth) oxide on viscosity of mold fluxes were investigated with a rotary viscometer. The results show that : (1) The viscositv of mold fluxes is remarkably inereased by RE oxide addition, especially when the mass fraction of RE oxide is more than 10%. (2) By addition of RE oxide, precipitation of the insohlble particles with high melting point from the molten slag with the decreasing of the temperature leads to the inerease of viscosity. Viscosity curve shows that RE oxide is soluble in some extent in mold fluxes. When RE oxide is in a state of supersaturation, the existence of insoluble particles also makes the viscosity of mold fluxes increase. (3) Not only the viscositv of nlold fluxes can be reduced, but also the capacity to dissolve and absorb RE oxide can be increased by Li2O, B2O3 and BaO. However, the contents of Li2O, B2O3, and BaO should be controlled to suitable levels. (4) The solidification temperature of mold fluxes can be increased by the addition of RE oxide, which is unfavorable to heat transfer and luhrication of mold fluxes between steel shell and mold.     

Effect of pickling process on removal of oxide layer on the surface of ferritic stainless steel

Oxide layer formed on stainless steel surface can result in a decrease in surface quality. Thus, it must be removed. In this paper, we investigated the effect of different pickling processes on removal of the oxide layer. Ferritic stainless steel was used as raw material. After it received annealing treatment, the components and structure of the oxide layer formed on its surface were studied. Then, the annealed stainless steel was pickled in hydrochloric acid solution system and mixed acid solution system, respectively. Results are as follows. The oxide layer on stainless steel surface has a thickness of 15–35?μm. With increase in hydrochloric acid concentration in hydrochloric acid pickling solution, the weight loss rate of stainless steel increases and is always greater than that in mixed acid pickling system. In addition, the surface of the stainless steel pickled in hydrochloric acid is smoother than that pickled in mixed acid. Furthermore, compared with channels in the oxide layer created during mixed acid pickling, those created during hydrochloric acid pickling are more, leading to shorter removal time. These results are important for increasing the pickling efficiency and improving the surface quality of stainless steel.     

基于TS-NGA的多作战智能体制导-攻击匹配优化

空中制导-攻击匹配(GAM)旨在确定武器单元、制导单元以及目标三者之间的最优匹配关系,以使多作战智能体任务联盟整体作战效能最大。分析了基于混合通信方式的多作战智能体制导-攻击匹配过程,建立制导攻击匹配约束优化问题模型,设计了一种禁忌策略的嵌套遗传算法(TS-NGA)对模型进行求解,算法的外层循环寻求武器单元和制导单元的最优配对,内层循环寻求武器单元和目标的最优配对。针对GAM问题特点,制定了编码与解码策略、交叉、变异规则以及选择、禁忌策略。仿真实验结果表明所设计求解算法能较好地解决三维变量的GAM问题模型。     

西方绅士化研究进展

从绅士化概念的提出与发展入手,回顾了西方绅士化现象的阶段特征与趋势、西方绅士化研究的四个重要阶段,从绅士化的类型衍化、绅士化概念工具的再发展、绅士化效应与抵抗、新自由城市主义与绅士化、尺度转向与星球绅士化等方面分析当代西方绅士化研究的新特点.在展望西方绅士化实证研究、理论建构、后效应对与研究方法的基础上,认为中国绅士化的研究应当重点关注本体论与认识论、前置条件、结构动力与制度条件的独特性.     

传感器网络节点定位精度的几何稀释分析

通过分析时间到达(Time of Arrival,TOA)算法的定位原理,利用定位精度的几何稀释(Geometrical Dilution ofPrecision,GDOP),描述定位误差与锚节点群几何布局关系,并给出基于测距的算法中GDOP的计算方法。采用蒙特卡罗仿真方法,仿真次数100,设定锚节点的测距误差相同,取锚节点数为3、5,对基于锚节点群内点、外点的未知节点定位误差的归一化GDOP值和GDOP均值求解,结合质心算法原理,验证了自身节点定位精度与确定该节点位置的锚节点的几何关系密切相关,得到锚节点群内点定位精度高的结论。