Solvent extraction kinetics of Sm(Ⅲ),Eu(Ⅲ) and Gd(Ⅲ) with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester

Solvent extraction kinetics of Sm(Ⅲ), Eu(Ⅲ) and Gd(Ⅲ) from hydrochloric acid have been focused on using2-ethylhexyl phosphoric acid-2-ethylhexyl ester(P507) with Anordning for Kontinuerlig Undersokning av Fordelningsfaktore vid Vatske Extraction(AKUFVE). Compared with the conventional set-up, some advantages emerge obviously, for example, fast phase separation, easy operation and convenience of kinetic data acquisition.First of all, the extraction mechanism was discussed based on the dimeric model of P507. Secondly, the effects of stirring speed were investigated and 420 r·min~(-1) was determined of the following experiments. The effects of pH, concentration of rare earth elements(REEs) and P507 on the extraction rate were analyzed. The results indicated that the extraction mechanism changed with the increasing concentration of P507. Then, the experiments with different temperature were carried out. It turned out that the values of apparent activation energy(E_a) for Sm(Ⅲ), Eu(Ⅲ) and Gd(Ⅲ) extracted by P507 were 26.80 kJ·mol~(-1), 13.40 kJ·mol~(-1) and11.10 kJ·mol~(-1) respectively, the resistance of the entire process was limited by diffusion or both of diffusion and reaction. Finally, the correlation equations were obtained, and the theoretical results fit with the experimental data well, most relative error was within ±30%.     

面向工程图档的信息识别与提取技术的研究和发展

在分析制造业中工程图档信息识别与提取技术的应用需求和研究意义的基础上,介绍了工程图档信息的分类,并分别阐述了针对纸介质数据与电子数据、几何与非几何信息进行识别与提取技术的研究现状.最后,探讨了此项技术在制造业向集成化、信息化、数字化的发展趋势下的研究前景.     

高粘度磁性液体在抽油泵滑动密封中的应用研究

将磁性液体和密封技术应用于油田专用管式抽油泵（柱塞泵）的间隙密封。结果表明，磁性液体密封抽油泵比普通泵泵效提高25％以上，并延长了检泵周期。     

Extraction and separation of yttrium from other rare earths in chloride medium by phosphorylcarboxylic acids

Two phosphorylcarboxylic acids, 3-((bis(2-ethylhexyloxy))phosphoryl)propanoic acid (PPA) and 3-((bis(2-ethylhexyloxy))phosphoryl)-3-phenylpropanoic acid (PPPA), were synthesized for separating yttrium from other rare earths in the chloride feed of ion-adsorption type rare earth concentrate. The effect of the factors such as pH_1/2, temperature, saponification degree and phase modifiers was investigated. The separation efficiencies of PPA and PPPA are obviously better than the typical extractants such as sec-octylphenoxy acetic acid (CA-12) and naphthenic acid (NA). The extraction process of rare earths by PPA and PPPA is a cation exchanging reaction, which is similar to those of CA-12 and NA. The loaded rare earths in both PPA and PPPA systems can be effectively back-extracted by 0.5 mol/L HCl or higher concentration. A cascade extraction process for separating yttrium from other rare earths was developed using PPPA as the extractant. The yttrium product with the purity of 97.20 wt% was obtained by 35 stages of extraction and 12 stages of scrubbing.     

矫正淬火在大型传动齿轮箱内齿圈渗碳淬火变形控制中的应用

零件热处理变形是一个永恒的课题,变形控制在热处理界一直都是热处理技术人员研究的难点.本文从工艺技术的角度,简要分析了大型、超薄内齿圈常温渗碳淬火工艺对变形的影响,以及淬火过程采用模具矫正对齿圈热处理变形控制的作用.     

萃取—火焰原子吸收光谱法测定水中的铬

本文研究了以DPC/MIBK为萃取体系,用火焰原子吸收分光光度法测定水中微量铬的方法.其灵敏度(ng·ml~(-1)/1%)为1.42.根据溶液酸度、萃取剂用量、萃取时间、相比等对吸光度的影响,选择确定较佳的萃取条件.其回收率在95～109%之间,相对标准偏差为4.65%(n=10).     

Novel calibration method for camera array in spherical arrangement

A camera array placed in a spherical arrangement facilitates a new paradigm for future interactive visual applications, and the calibration of the cameras is a crucial task for such implementation. It is difficult to apply previous calibration methods to this special camera system because opposite features can commonly be found among the opposing cameras used in this system. In this case, a part-by-part calibration may fail in terms of error accumulation. In this paper, we propose an opposite feature based camera calibration method for a camera array in a spherical arrangement. An adaptive scheme is designed on a cube with opposite colour patterns and optimisations in handling the above problem of opposite features being invisible to cameras at opposite positions, based upon which, with our method, a common visible feature point is not required in advance. By applying a practical camera array in a spherical arrangement, and using 3D modelling, the superiority of the proposed method was verified through computer simulations. The results demonstrate that the proposed calibration method can contribute to the imaging system and future visual applications.     

基于邻居网络的科学文献关键词提取

从单个文档中直接提取关键词不能满足关键词提取的精度要求,而现有基于邻居信息的关键词提取相关研究又耗时较长.因此,文中提出利用科学文献中共同作者关系以构建邻居网络,并联合使用这些邻居网络信息及文档本身内容提取关键词的方法.在此基础上,进一步提出利用领域知识中高频度共现词对以提取关键词,获得更高质量的关键词的方法.实验表明,文中方法性能较优.     

AsP/InSe Van der Waals Tunneling Heterojunctions with Ultrahigh Reverse Rectification Ratio and High Photosensitivity

Van der Waals heterojunctions made of 2D materials offer competitive opportunities in designing and achieving multifunctional and high‐performance electronic and optoelectronic devices. However, due to the significant reverse tunneling current in such thin p–n junctions, a low rectification ratio along with a large reverse current is often inevitable for the heterojunctions. Here, a vertically stacked van der Waals heterojunction (vdWH) tunneling device is reported consisting of black arsenic phosphorus (AsP) and indium selenide (InSe), which shows a record high reverse rectification ratio exceeding 10⁷ along with an unusual ultralow forward current below picoampere and a high current on/off ratio over 10⁸ simultaneously at room temperature under the proper band alignment design of both the Schottky junction and the heterojunction. Therefore, the vdWH tunneling device can function as an ultrasensitive photodetector with an ultrahigh light on/off ratio of 1 × 10⁷, a comparable responsivity of around 1 A W^?1, and a high detectivity over 1 × 10¹² Jones in the visible wavelength range. Furthermore, the device exhibits a clear photovoltaic effect and shows a spectral detection capability up to 1550 nm. The work sheds light on developing future electronic and optoelectronic multifunctional devices based on the van der Waals integration of 2D materials with designed band alignment.     

基于卷积神经网络的钣金件表面缺陷分类识别方法

针对国防军工、电子信息等领域对多批次、小批量钣金零件快速、智能制造的需求,提出了一种基于卷积神经网络的少样本钣金件表面缺陷分类识别方法。首先基于卷积神经网络的网络架构,搭建出了经典的分类模型,并在实验中进行了参数修改,以达到实际生产中的表面缺陷检测要求;其次利用缺陷分割提取的方法获得卷积网络训练模型的样本集,并进行数据增强。实验结果表明,该模型的准确度可达97.02%;最后利用窗口滑移检测方法使待检测零件与模型进行对比,实现了对缺陷的分类和缺陷位置的标记。经实验验证,该方法的准确性和实时性均可满足实际工业生产要求。