添加WC对镍基合金激光熔敷层硬度及腐蚀磨损行为的影响

探讨了添加ＷＣ的镍基合金Ｇ１１２激光熔敷层的性能，结果表明，添加２０％ＷＣ的激光熔敷层的硬度ＨＶ０．２比末添加的提高近一倍，在酸性介质中的耐蚀性有所降低，但腐蚀磨损性能却得到大改善，其腐蚀磨损机制在低冲击速度下，由犁削磨损，坑穴腐蚀及应力腐蚀变为犁削磨损为主，在高冲击速度下，两者的腐蚀磨损机制趋于一致，均为犁削磨损为主，伴以抗穴腐蚀及应力腐蚀。     

液压夹具夹持力对金属材料室温拉伸曲线的影响及处理

针对日常检测中金属材料室温拉伸曲线出现的异常现象,分析材料试验机液压夹具夹持力大小对金属材料室温拉伸曲线的影响情况。结果表明:液压夹具夹持力对拉伸曲线的影响不可忽视,应注意观察试样最大拉力并适时调整夹具夹持力;在判明曲线异常为液压夹具夹持力所致时,应人为处理曲线得出正确测试结果。     

函数相关论初探

本文剖析了事物发展过程的相似性与接近性,给出了函数相关度定义,讨论了函数相关度的基本性质;同时阐明了函数相关分析的一般过程     

灰色补偿神经网络及其应用研究

本文给出了灰色系统与神经网络的一种新的结合方式—灰色补偿神经网络。该网络利用神经网络建立残差与数据间的映射关系,并采用其预测结果补偿灰色系统模型的预测值。仿真结果表明本方法优于其它灰色神经网络。     

不同海拔高度下γ射线空气衰减系数的计算

在航空γ剂量率测量过程中由于海拔高度跨度大,γ射线空气衰减系数会受到海拔高度、温度、气压与空气密度的影响,故需要进行相应修正。利用蒙特卡罗（MCNP）法模拟γ射线在不同空气密度下的线衰减系数。利用经验公式计算不同海拔高度下的空气密度,利用MCNP法建立γ谱仪模型,计算不同海拔高度、不同密度条件下的γ光子注量,根据指数衰减原理计算不同空气密度下的线衰减系数。结果表明,由经验公式求出的空气密度模拟得出的空气质量衰减系数与美国NIST推荐值最大相对误差为-17.3%;在γ射线参考辐射场中用衰减板进行实验验证,⁶⁰Co源的最大相对误差为6.0%,¹³⁷Cs源的最大相对误差为5.3%。本工作为后续低空近地辐射剂量的研究工作奠定了基础。     

Zinc ferrite based gas sensors: A review

Flammable, explosive and toxic gases, such as hydrogen, hydrogen sulfide and volatile organic compounds vapor, are major threats to the ecological environment safety and human health. Among the available technologies, gas sensing is a vital component, and has been widely studied in literature for early detection and warning. As a metal oxide semiconductor, zinc ferrite (ZnFe₂O₄) represents a kind of promising gas sensing material with a spinel structure, which also shows a fine gas sensing performance to reducing gases. Due to its great potentials and widespread applications, this article is intended to provide a review on the latest development in zinc ferrite based gas sensors. We first discuss the general gas sensing mechanism of ZnFe₂O₄ sensor. This is followed by a review of the recent progress about zinc ferrite based gas sensors from several aspects: different micro-morphology, element doping and heterostructure materials. In the end, we propose that combining ZnFe₂O₄ which provides unique microstructure (such as the multi-layer porous shells hollow structure), with the semiconductors such as graphene, which provide excellent physical properties. It is expected that the mentioned composites contribute to improving selectivity, long-term stability, and other sensing performance of sensors at room or low temperature.     

Team O2AS' approach for the task-board task of the World Robot Challenge 2018

ABSTRACT

In this paper, we describe the approach of Team O2AS to complete the task-board task of the World Robot Challenge 2018, held in Tokyo. We use a custom gripper and graspable tools with in-built compliance to work with various kinds of parts, increase robustness against uncertainties, and to avoid complicated control strategies. The robots are able to finish all the sub-tasks without the need to exchange grippers. The main idea is to use mechanical compliance and self-centering mechanisms to deal with uncertainty. This is achieved by aligning the objects using either the gripper and tools, or by the design of the robot motions.     

Team O2AS at the world robot summit 2018: an approach to robotic kitting and assembly tasks using general purpose grippers and tools

ABSTRACT

In this article, we propose a versatile robotic system for kitting and assembly tasks which uses no jigs or commercial tool changers. Instead of specialized end effectors, it uses its two-finger grippers to grasp and hold tools to perform subtasks such as screwing and suctioning. A third gripper is used as a precision picking and centering tool, and uses in-built passive compliance to compensate for small position errors and uncertainty. A novel grasp point detection for bin picking is described for the kitting task, using a single depth map. Using the proposed system we competed in the Assembly Challenge of the Industrial Robotics Category of the World Robot Challenge at the World Robot Summit 2018, obtaining 4th place and the SICE award for lean design and versatile tool use. We show the effectiveness of our approach through experiments performed during the competition.     

离子液体中采用AGET ATRP法制备MCC-g-PGMA

在氯化1-烯丙基-3-甲基咪唑([AMIM]Cl)离子液体中, 采用AGET ATRP技术, 以VC为还原剂、CuBr₂/乙二胺为催化体系, 成功制备了微晶纤维素接枝聚甲基丙烯酸缩水甘油酯(MCC-g-PGMA)分子。研究表明:[AMIM]Cl对微晶纤维素有较好的溶解性, 最佳反应条件为GMA/乙二胺/CuBr₂/VC摩尔比为100:4:1:1, 反应温度25℃, 反应时间4 h, 接枝效率可达54.56%, 分子量分布较窄为1.48。通过FT-IR、TEM和SEM测试表明:成功合成了MCC-g-PGMA接枝共聚物分子, PGMA接枝微晶纤维素后表面形态变得粗糙, 接枝共聚物在丙酮溶液中可自组装成150～200 nm的球形结构, 在药物载体领域具有良好的应用潜能。