摘要：We developed a scheme based on wood surface novel wood recognition spectral features that aimed to solve three problems. First was elimination of noise in some bands of wood spectral reflection curves. Second was improvement of wood feature selection based on analysis of wood spectral data. The wood spectral band is 350-2500 nm, a 2150D vector with a spectral sampling interval of 1 nm. We developed a feature selection proce- dure and a filtering procedure by solving the eigenvalues of the dispersion matrix. Third, we optimized the design for the indoor radian＇s mounting height. We used a genetic algorithm to solve the optimal radian＇s height so that the spectral reflection curves had the best classification infor- mation for wood species. Experiments on fivecommon wood species in northeast China showed overall recogni- tion accuracy 〉95 % at optimal recognition velocity.

摘要：A well-designed redox-active organic linker,pyrazine-2,3,5,6-tetracarboxylate(H_4pztc)with brimming active sites for lithium ions storage was utilized to construct coordination polymers(CPs)via a facile hydrothermal *** two isostructural two-dimensional(2D)CPs,namely[M_2(pztc)(H_2O)_6]_n(M=Co for 1 and Ni for 2),delivered excellent reversible capacities and stable cycling performance as anodes in lithium ion *** demonstrated in electrochemical studies,1 and 2 can achieve highly reversible capacities of 815 and 536 mA h g^(-1)at 200 mA g^(-1)for 150 cycles,respectively,best performed for the reported2D-CP-based anode *** electrochemical mechanism studies showed that the remarkable performances can be ascribed to the synergistic Li-storage redox reactions of metal centers and organic *** work highlights the opportunities of using a well-designed organic ligand to construct low-dimensional CPs as new type of electrode materials for advanced lithium ion batteries.

摘要：A native organ has heterogeneous structures, sirength, and cell components. It is a big challenge to fabricate organ prototypes with controllable shapes, strength, and cells. Herein, a hybrid method is developed to fabricate organ prototypes with controlled cell deposition by integrating extrusion-based 3D printing, electrospinning, and 3D bioprinting. Multi-scale sheets were first fabricated by 3D printing and electrospinning;then, all the sheets were assembled into organ prototypes by sol-gel react io n duri ng bioprinting. With this method, macroscale structures fabricated by 3D printing ensure the customized structures and provide mechanical support, nanoscale structures fabricated by electrospinning offer a favorable environment for cell growth, and different types of cells with controllable densities are deposited in accurate locations by bioprinting. The results show that L929 mouse fibroblasts encapsulated in the structures exhibited over 90% survival within 10 days and maintai ned a high proliferation rate. Furthermore, the cells grew in spherical shapes first and then migrated to the nano scale fibers showing stretched morphology. Additionally, a branched vascular structure was successfully fabricated using the presented method. Compared with other methods, this strategy offers an easy way to simultancously realize the shape control, nanolibrous structures, and cell accurate deposition, which will have potemidi applications in tissue cngineering.

摘要：Filtering media is anything placed in a filter that changes the quality of water flowing through *** the variety of media available,proper selection of filter media is of great importance for filter *** glass is evaluated as an alternative to silica sand in media filters and is an effective medium with the advantages of lower cost than silica sand,more environmental friendliness as it is a recycled product,and ease to pulverize into different sizes for specific design ***,the filtration efficiency of regenerated recycled glass is limited by the formation of biofilms on its surfaces due to the large number of microorganisms such as bacteria and algae existing in the *** this study,hydrofluoric(HF)acid etched glass spheres(GSs)modified with polydopamine(PDA)and silver nanoparticles(PDA-AgHF/GSs)were fabricated on the surface of soda-lime GSs by HF etching,crystal in situ growth,and PDA *** etching and the modification of PDA coating imparted good hydrophilicity to PDA-Ag-HF/*** modification of the silver coating also rendered PDA-Ag-HF/GSs excellent antibacterial properties and reduced Chlorella adhesion,and inhibited microorganism growth ability by releasing Ag^+.The catechol functional group on the PDA coating could regulate the Ag^+release by *** antibacterial properties,anti-algae adhesion,and controlled release of Ag^+indicate that PDA-Ag-HF/GS coating can effectively inhibit the formation of biofilm on the surface of the material,providing a new strategy for the formation of anti-biofilm.

摘要：基于Variable-cycle engine(VCE)模式切换的功能需求,提出一种传动切换机构(driving and switching mechanism,DSM)的通用设计方法。先利用双排行星轮系(double row planetary gear train,DRPGT)架构设计出一种具备相位和传动比同时可变特征的通用传动机构方案,再通过构型设计拓扑出功能结构相似的系列化机构方案,并采用粗糙集理论结合聚类分析法开展其类型综合与分类研究。最后分析得到一类前排为单行星轮系,后排为双行星轮系的串联传动机构方案,此类方案满足VCE模式切换工作需求,且具备紧急情况下中断动力传递的功能。研究证明:设计分析方法应用于机构类型综合与分类研究高效可靠。

摘要：以电动制式低真空磁悬浮系统的运输能力影响因素及能力范围为研究目的,从电动制式低真空磁悬浮系统速度高、阻力小、运行环境封闭的技术特点出发,分析对系统运输能力存在影响的限制因素,重点通过对车站分布需求、列车性能、道岔系统、列控系统、通过能力等明显影响运输能力的5个因素展开研究,采用理论分析法、软件仿真分析法、数值计算法等方法分析磁悬浮系统运输能力计算影响效果,得出电动制式低真空磁悬浮系统的运输能力范围结论。研究假设低真空超高速磁浮系统列车2~8辆编组形式,模拟列车区间追踪运行、车站折返等不同工况,分析系统追踪间隔及列车折返能力,科学、客观地提出高峰小时运输能力,并预测系统运输能力范围。

摘要：薯蓣皂素是一种天然甾体皂苷元,可作为数百种类固醇药物的前体,具有重要药用价值。目前工业生产薯蓣皂素主要依赖化学提取法,因此该法依赖植物材料和耕地且对环境有害。随着代谢工程和合成生物学的发展,生物合成法受到广泛关注。文中综述了生物合成薯蓣皂素的代谢途径和关键酶,并在酿酒酵母Saccharomyces cerevisiae中设计其异源合成途径,提出改造策略,以期为全生物合成薯蓣皂素提供有价值的参考。

摘要：装备制造业是为国民经济和国防建设提供生产技术装备的基础性产业,其产品的制造周期长,资源消耗大,在制造过程中往往需要针对不同的生产阶段采取多批次的资源采购策略。为降低库存成本,在保证生产进度的前提下制定合理的采购策略,从产品的生产计划中提取工序的关键信息,建立了基于采购时间序列的库存成本优化模型,并在保证生产进度的前提下,运用改进灰狼优化算法对该模型进行求解,得到了最优采购策略。以某建材装备制造企业的生产资源采购策略优化问题为例,设计了对比实验,验证了优化方法的合理性和有效性。

摘要：现代社会经济的快速发展和城市人口数量的急剧增长给交通运输行业带来了巨大的运营难度,由此产生的车站、车厢过度拥挤及交通网络延迟等问题已成为我国建设“智慧交通”面临的重要问题之一。针对城市轨道交通高峰时段大客流组织而导致的站台候车乘客出行安全问题,以单条城市轨道交通线路为研究对象,提出考虑预警机制和开行方案的多车站客流控制方法,为高峰时段的客流控制问题提供理论依据。考虑列车开行方案、车站客流控制及乘客上下车过程等约束,构建以乘客平均延误时间和车站最大平均限流时间最小化为目标的数学模型。其中决策变量为进站乘客数量和车站平均限流时间,并采用线性加权法将原目标模型转化为单目标模型;在此基础上,针对问题特性,设计混合禁忌搜索算法进行求解。数值实验对问题特性进行分析,并通过多组算例与实际案例验证模型的正确性及算法的有效性。研究结果表明:考虑车站平均限流时间可以提高乘客乘车公平性,缓解全线车站客流拥挤;合理设置站台客流预警等级可以提高乘客出行满意度;采用大小交路和小交路列车不同编组的混合策略可提高运输效率,并在一定程度上降低企业成本;针对大规模问题,混合禁忌搜索算法可以在短时间内求解并获得更高质量的解。

摘要：分析现有供应链数据交换系统在商务实时性方面的不足,提出采用RFID数据采集简化供应链流程的思想,设计了基于RFID的供应链数据交换系统模型,给出了RFID与RosettaNet报文交换系统的设计方案,以及系统实现的实例流程.