The capacitated multi-AGV scheduling problem with conflicting products: Model and a decentralized multi-agent approach

Automated guided vehicles (AGVs) are a key technology to facilitate flexible production systems in the context of Industry 4.0. This paper investigates an optimization model and a solution using a decentralized multi-agent approach for a new capacitated multi-AGV scheduling problem with conflicting products (CMASPCP) to take full advantage of AGVs. The novelty of the problem and our model lies in the introduction of AGV capacity constraints and constraints arising from conflicting products, i.e. products that cannot be transported together. As the new I4.0 paradigm tends towards decentralized control, we also present a decentralized multi-agent approach in which AGVs autonomously coordinate to solve the task. The performance of the proposed decentralized approach is compared to a mixed-integer linear programming model on a set of 110 problem instances with different sizes and degrees of complexity. The obtained results show that the proposed decentralized multi-agent approach is effective and competitive in terms of the solution quality and computational time.     

Comparing the pozzolanic behavior of sugar cane bagasse ash to amorphous and crystalline SiO2

The present paper aims to clarify the pozzolanic behavior of sugar cane bagasse ash-SCBA by comparing it to amorphous and crystalline silica. It is shown that calcium silicate hydrate is formed in lime solution with SCBA but the reaction is slow and does not consume all the material. Comparing its results with the obtained in tests with silica fume and with crushed quartz show a better agreement with the latter. Characterization of cement pastes shows 20% of cement replacement by sugar cane bagasse ash leads to only a minor reduction in the amount of calcium hydroxide formed. This behavior is also closer to the observed in quartz than in silica fume. The results suggest SCBA should be used as a replacement for inert constituents in cement composites rather than pozzolanic addition. Analysis of the microstructure of the cement pastes revealed the presence of calcium hydroxide in samples prepared with partial replacement by silica fume, quartz and sugar cane bagasse ash. The presence of this phase in the sample prepared with silica fume was attributed to agglomeration of the particles that affected the reactivity of this material.     

“互联网+”与传统家电产品的创新之路

目的以"互联网+"理念的出现为启示,论述了"互联网+"理念的特点及其对传统家电行业的影响。方法分析了"互联网+"对传统家电产品设计的启发和创新,进而阐明了"互联网+"理念在家电产品设计中的创新运用,为其开辟了一条新的道路。比如"互联网+"对传统家电产品的影响,以及"互联网+"怎样与传统家电产品相结合。结论在此基础上,提出了家电产品设计必须善于利用互联网这个工具,用互联网给设计带来更多的创新点,才能给家电产品行业带来更广阔的市场。     

不同气氛对TATB基含铝炸药爆热的影响

为了测定三氨基三硝基苯(TATB)基含铝炸药在不同气氛中的爆热,使用绝热式量热弹对其压装药在真空、0.1 MPa氮气、0.1 MPa空气、0.1 MPa氧气和1.5 MPa氧气条件下的爆热进行了测量,研究了其能量释放规律,并使用X射线衍射(XRD)对固相产物成分进行了分析。结果表明:TATB基含铝炸药在真空、0.1 MPa氮气、0.1 MPa空气、0.1 MPa氧气和1.5 MPa氧气条件下的爆热依次增加;环境中压力的增加会导致爆热值增大,在0.1MPa氮气中,TATB基含铝炸药的爆热值比真空中增加了15.7%。环境中氧气量的增加也使爆热值增大:0.1 MPa空气中的爆热值比0.1 MPa氮气中增加了7.8%,0.1 MPa氧气中的爆热值比0.1 MPa氮气中高出49.7%,1.5MPa氧气中的爆热值比0.1 MPa氮气中高出146.1%。在富氧气氛下测试TATB基含铝炸药的爆热时,所测爆热接近于炸药的燃烧热,且爆炸产物的XRD结果也表明Al粉已基本氧化完全。同时,在0.1 MPa氮气气氛下没有检测到氮化物Al N的存在。该方法可对不同气氛下含铝炸药的爆热进行测量,并对爆炸产物中Al的存在形式进行分析。     

多糖类可吸收材料降解产物分析方法研究进展

多糖类可吸收材料因来源丰富、生物相容性好、在人体内易被降解吸收而引起了人们的广泛关注,但国内外缺乏相关评价标准,其安全性评价存在较大难度,因而对多糖类可吸收材料降解产物的分析是不可或缺的。对多糖类可吸收材料及其降解产物进行了介绍,重点综述了多糖材料降解产物的体内外分析方法,并对当前存在的问题进行了展望,旨在为多糖类可吸收材料降解产物的分析提供一定的思路。     

我国木质品质量问题发生的特征分析——基于877家木质品企业抽检不合格产品

本文在877家木业企业产品质量抽检公告资料基础上,从时空趋势、产品类别和品牌、质量问题原因三个维度分析了木质品质量问题发生的特征.结果显示:近年来,我国木质品行业产品抽检不合格率呈现明显下降趋势;抽检不合格木质品频次具有地区分布不平衡特征,广东、山东、江苏、河北、四川发生频次偏高;木质品出现质量问题的产品以人造板和木制家具为主;品牌对木质品质量的保障作用并不明显,品牌企业产品中不合格者占比偏高;木质品质量问题的三大表现是甲醛超标、力学性能不合格、吸水厚度膨胀率.     

High‐rise concrete and clay block masonry building in Brazil

Brazilian structural concrete and clay block masonry construction shares many common features with construction all over the world: blocks of a similar shape are bedded in mortar, vertical and horizontal reinforcement is placed in grouted cells, engineering analysis and design follows universal principles and local design codes mimic those adopted elsewhere. However, loadbearing masonry construction in Brazil has become one of the most preferred high‐rise building systems due to its cost‐effectiveness and ease of construction compared to normal reinforced concrete solutions. This paper provides an overview of loadbearing masonry building in Brazil, including case studies on notable high‐rise masonry structures, with an overview of how Brazilian materials, codes and practices differ from the rest of the world. Finally, the paper explains how the use of high‐strength units assists the growing demand for taller and taller buildings and provides insight into why owners and general contractors often prefer to use structural masonry.     

微酸性电解水在水产品保鲜加工中的应用研究进展

目的 对微酸性电解水在水产品保鲜加工中的应用研究进展进行总结,为后续研究提供理论参考。方法 在介绍微酸性电解水制备原理与作用机制的基础上,围绕该技术在水产品保鲜加工中的应用研究进展予以阐述,提出存在问题与解决办法。结果 水产品经微酸性电解水处理后,可明显抑制水产品中的微生物生长,延缓pH值升高,改善保水性能,保持产品色泽,提升质构特性。然而,随着消费者对水产品品质要求的不断提高,仅使用微酸性电解水处理并非理想的方式,可结合其他理化与生物保鲜技术,以提升微酸性电解水的综合作用效果。结论 微酸性电解水在水产品保鲜加工中占有一定优势,且能结合其他处理方式提升其在水产品杀菌保鲜与品质保持等方面的加工效率。     

生鲜水产品保鲜膜和保鲜衬垫的应用及研究进展

目的 阐明提高生鲜水产品贮藏保鲜性能的适用方法,指出现有水产品保鲜技术和保鲜材料存在的问题及不足,对未来生鲜水产品保鲜材料的发展作出展望性分析。方法 介绍生鲜水产品保鲜常用的物理、化学和生物保鲜技术的优势和不足。从分类、应用范围及抗菌、抗氧化等性能多角度出发分析保鲜膜、保鲜衬垫的研究现状。结果 传统的保鲜技术虽对生鲜水产品有一定的保鲜作用,但其保鲜性能有限,保鲜膜、保鲜衬垫辅以抗菌、抗氧化等性能的生物保鲜剂,可延长生鲜水产品的货架期。结论 保鲜膜、保鲜衬垫同生物保鲜剂联合使用,以获得具有高效、长效保鲜性能的新型保鲜材料,提高了生鲜水产品的鲜度品质。新型保鲜材料具有广阔的发展前景。