随机工时下柔性加工车间的鲁棒优化调度方法

为了提高柔性加工车间调度方案的可行性、保障生产过程的稳定性,提出一种鲁棒优化调度方法。引入两个不确定参数来描述随机工时的波动程度和约束条件的允许违背程度,提出随机变量服从概率分布时一般线性规划问题的鲁棒优化方法。采用该方法将含随机工时而难以求解的随机型柔性加工车间调度模型转化为确定型鲁棒对等模型。基于该模型,将随机工时融入适应度函数中,结合遗传进化的全局优化和邻域搜索的空间拓展能力研制出鲁棒调度算法,同步实现工件排序和机器分配的双重决策。案例测试表明,所提方法可以在较短计算时间内、以较小性能损失、将近95%的置信度获得当前最优解。     

考虑运输时间柔性作业车间调度问题的快速寻优方法

为了快速获得考虑运输时间的柔性生产调度问题的近优解,进行了快速寻优方法研究。采用运输时间矩阵对析取图模型进行改进,建立了设备选择的多阶段决策方法。建立了考虑运输时间的关键链优化方法,通过邻域搜索快速获得近优解。开发了调度实验系统对上述工作进行验证。实验结果表明,该方法可较稳定地获得近优调度解,并具有较好的计算效率。     

石墨烯在含能材料中的应用研究进展

从石墨烯及其复合物催化剂、石墨烯添加剂和石墨烯及其复合含能材料等3个方面,介绍了近年来石墨烯在含能材料应用方面的最新研究进展。认为石墨烯及其复合催化剂对推进剂含能组分具有明显的催化作用;添加石墨烯后,推进剂燃烧及力学性能得到改善;氧化石墨烯及石墨烯构成的钝感剂可降低含能材料的机械感度;石墨烯及其复合物含能材料具有优异的性能,更大的能量释放率。提出了石墨烯在含能材料领域的发展方向和应用前景。附参考文献42篇。     

Recent Progress of Innovative Perovskite Hybrid Solar Cells

Recently, innovative perovskite hybrid solar cells have attracted great interest in solar cell research fields, such as dye-sensitized solar cells, organic photovoltaics, thin-film solar cells, and silicon solar cells, because their device efficiencies are gradually approaching those of crystalline Si solar cells, and they can be fabricated by cheap low-temperature solution processes. Here, we review the recent progress of innovative perovskite hybrid solar cells. The introduction includes the general concerns about solar cells and why we need innovative solar cells. The second part explains the structure and the material properties of hybrid perovskite materials. We focus on why the hybrid perovskite materials can exhibit excellent solar cell properties, such as high open-circuit voltage. The third part introduces recent progress in innovative perovskite hybrid solar cells, in terms of device architecture and deposition methods for dense perovskite thin films with full surface coverage. The device architecture is important in attaining high power conversion efficiency; the device operating mechanism is dependent on the device structure; and the pinhole-free dense perovskite thin films with full surface coverage are crucial for achieving high efficiency. Finally, we summarize the recent progress in perovskite hybrid solar cells, and the issues to be solved, in the summary and outlook section.     

Recent Advances in Counter Electrodes for Thiolate-mediated Dye-sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) based on disulfide/thiolate (T₂/T⁻) redox couples have attracted remarkable attention due to their high efficiency and low cost. As an indispensible part of DSSCs, counter electrode (CE) design plays a crucial role in high efficiency DSSCs. This mini-review paper selectively reviews the recent advances in T-mediated DSSCs using novel CE (namely cathode) materials, mainly including noble metal platinum (Pt), carbon materials, transition metal compounds (TMCs), polymers, and hybrids, thus highlighting the merits and demerits of alternative Pt catalysts, and the prospects and challenges of Pt-free CEs for the development of high-performance and low-cost DSSCs.     

车间底漆在船厂生产线应用对比

在船厂生产线上将水性无机锌底漆和无机硅酸锌车间底漆进行对比试验研究,重点探讨了水性无机锌车间底漆在生产线的适用性,实验显示,水性无机锌车间底漆可以在预处理流水线上使用,其干燥时间、附着力、焊接与切割、耐候性等方面能达到船厂生产线的要求。     

美国生态主题科幻电影的启示

美国作为世界上科技最发达的国家,制作了数量巨大,主题多样,影响深远的科幻电影。通过抽取美国电影史上极具代表性的生态主题科幻电影作为样本,分析这些科幻影片所反映的人与自然的关系,以及科技发展与科幻电影的关系,对生态主题科幻电影进行哲学反思,希望有助于推动科技理性发展,同时维护科学技术与自然生态环境间和谐发展的关系。     

Coupling human mobility and social ties

Studies using massive, passively collected data from communication technologies have revealed many ubiquitous aspects of social networks, helping us understand and model social media, information diffusion and organizational dynamics. More recently, these data have come tagged with geographical information, enabling studies of human mobility patterns and the science of cities. We combine these two pursuits and uncover reproducible mobility patterns among social contacts. First, we introduce measures of mobility similarity and predictability and measure them for populations of users in three large urban areas. We find individuals'' visitations patterns are far more similar to and predictable by social contacts than strangers and that these measures are positively correlated with tie strength. Unsupervised clustering of hourly variations in mobility similarity identifies three categories of social ties and suggests geography is an important feature to contextualize social relationships. We find that the composition of a user''s ego network in terms of the type of contacts they keep is correlated with mobility behaviour. Finally, we extend a popular mobility model to include movement choices based on social contacts and compare its ability to reproduce empirical measurements with two additional models of mobility.     

推进绿色矿山建设工作与实践

建设绿色矿山是保证矿业可持续健康发展的必由之路,是实现科学发展观、社会和谐的必然选择。介绍了绿色矿山的定义和绿色矿山建设的重要性。从科创新、资源节约与综合利用、节能减排、地质灾害治理和环境保护、土地复垦、社区和谐以及企业文化方面总结了三鑫公司推进绿色矿山建设工作与实践。     

高校给排水科学与工程专业实习实效性探索

专业实习是给排水科学与工程专业重要的教学环节,对学生的能力培养起到了至关重要的作用。本文针对目前给排水科学与工程专业实习教学的现在和存在问题,特别是在卓越工程师教育培养的目标下,探讨为达到培养卓越工程师高级用于型人才的目的,提出了建立稳定的实习基地、多元化的考核方式,加强教师工程实践能力培养与合理利用实习经费等措施。