多部件设备维修问题研究及遗传算法求解

合理组织设备维修，缩短设备维修时间是生产运营管理的一个重要环节。本文探讨了多部件设备维修的有效组织问题。考虑到维修工人对拆分后设备的不同部分具有不同的维修效率，提出了一种基于维修时间优化的决策方法，将其与经典指派方法进行了比较；进一步地，对这一NP-hard问题设计了遗传算法，通过数值例子讨论了其求解有效性。     

多组分间歇精馏工艺计算探讨

介绍用“微元时段”计算多组分间歇精馏的方法。     

INTROGRESSING PHEROMONE QTL BETWEEN SPECIES: TOWARDS AN EVOLUTIONARY UNDERSTANDING OF DIFFERENTIATION IN SEXUAL COMMUNICATION

As a first step toward understanding how noctuid moths evolve species-specific pheromone communication systems, we hybridized and backcrossed two closely related moth species, Heliothis virescens (Hv) and H. subflexa (Hs), which differ qualitatively and quantitatively in their multi-component sex pheromone blends. We used amplified fragment length polymorphism (AFLP) marker-based mapping of backcross families to determine which of the 30 autosomes in these moths contained quantitative trait loci (QTL) controlling the percentages of specific chemical components in the pheromone blends. In two previous backcrosses to Hs, we found a strong depressive effect of Hv-chromosome 22 on the percentage of three acetate components in the pheromone gland. These acetates are present in Hs and absent in Hv. Here, we describe how we introgressed Hv-chromosome 22 into the genomic background of Hs. Selection for Hv-chromosome 22 started from backcross 3 (BC₃) females. All females that had Hv-chromosome 22 and a low percentage of acetates (< 3% of the total amount of pheromone components present) were backcrossed to Hs males. In BC₅ to BC₈, we determined whether Hv-chromosome 22 was present by a) running only the primer pairs that would yield the markers for that chromosome, and/or b) determining the relative percentages of acetates in the pheromone glands. Either or both genotype and phenotype were used as a criterion to continue to backcross these females to Hs males. In BC₉, we confirmed the isolation of Hv-chromosome 22 in the Hs genomic background, and backcrossed the males to Hs females to eliminate the Hv-sex chromosome as well as mitochondrial DNA. The pheromone composition was determined in BC₃, BC₅, and BC₁₁ females with and without Hv-chromosome 22. All backcross females with Hv-chromosome 22 contained significantly less acetates than females without this chromosome. In addition, BC₃ females with Hv-chromosome 22 contained significantly more Z11-16:OH than BC₃ females without Hv-chromosome 22. However, in BC₅ and BC₁₁ females, the correlation between Z11-16:OH and Hv-chromosome 22 was lost, suggesting that there are separate QTL for the acetates and for Z11-16:OH, and that the relative amount of the alcohol component is only affected in epistasis with other (minor) QTL. Now that we have succeeded in isolating the chromosome that has a major effect on acetate production, we can test in behavioral experiments whether the presence of acetates may have been a driving force for a shift in pheromone composition. Such tests are necessary to move towards an evolutionary understanding of the differentiation in sexual communication in Heliothis spp. moths.     

往复式瓦斯压缩机节能研究概述

主要介绍往复式瓦斯压缩机性能参数,包括排气量、排气压力和功率效率等,并分析了影响往复式压缩机性能参数的因素.重点介绍往复式压缩机流量调节和节能控制的原理与方法,以及进气压力变化和混合气体组分变化对往复式瓦斯压缩机效能的影响.     

无机盐复合体系脱除SO42-的工艺研究

研究了多组分无机盐溶液的性质,以石灰石及浓盐酸等原料反应生成的液体CaCl2作为添加剂,考察和比较了液体CaCl2用量、反应温度、反应时间等因素对SO42-去除率影响。在此基础上,对比其处理成本,得最佳工艺条件:添加剂的钙离子和原盐溶液中硫酸根离子的摩尔比为0.760,反应温度为30℃,反应时间为4 h,搅拌速度为60 rmp时可得到SO42-<5 g/L的满意效果,达到了企业的要求标准,具有一定的应用价值和商业价值。     

关于有效解决多组分沉积物问题的研究

纸厂中的沉积物通常含有多种组分,其主要来源于机械浆、回用纤维、涂布损纸以及过程添加剂等多种原料.通常这些沉积物中某一组分可作为沉积作用的主要引发剂,同时也可作为其他原料之间的粘合剂,因此对这种引发剂进行鉴定和处理对减少胶粘物的沉积具有重要意义.另一方面,在胶粘物沉积现象严重的过程中,其还可以帮助有效地鉴别二次胶粘物.然而,要准确鉴别这种引发剂还有一定的难度.作者对纸厂胶粘物的沉积、浆料、沉积机理以及沉积物本身的组成等进行了研究,以期建立一种可靠的方法,有效地鉴别目前以及将来引发沉积物沉积的引发剂.     

基于拆卸序列的多部件设备机会维护策略研究

针对多部件设备进行维护时未考虑需要拆卸的问题,建立了一种基于拆卸序列的多部件设备机会维护策略模型.首先,以拆卸混合图表示部件间的拆卸序列,进而得出各部件的拆卸时间和拆卸成本;然后针对各部件的衰退过程,结合役龄递减因子和故障率递增因子的混合故障率来描述各部件的衰退特性;其次,在此基础上,以设备的机会维护时间窗为决策变量,在设备满足一定可用度的情况下,以设备在有限运行时间内的最低维护成本为优化目标,求解设备的最优预防维护计划;最后,通过数值仿真分析,验证所提出的多部件设备机会维护策略的有效性.     

二次硬化合金钢中多组元强化相M2C碳化物的粗化动力学研究

高Co—Ni超高强度合金钢在482℃等温回火处理，首先析出渗碳体，回火30min后，针状合金碳化物M2C以共格方式从基体α—Fe中析出．回火时间延长到10h以上，M2C仍与基体间保持良好的共格关系，该共格关系会随过时效而失去．高分辨电镜观察表明，M2C的尺寸r和回火时间t接近r^2αt关系，明显偏离扩散控制的三次方关系的经典LSW粗化理论，对相近的合金钢材料有关M2C析出动力学实验数据进行分析得到相似的结论．这不仅和第二相碳化物的形态有关，还与多组元扩散的体系相关，表明经典理论不完全适合多组分的碳化物粗化行为从经典扩散理论出发，考虑针状沉淀相多元扩散问题，得到的针状相粒子粗化方程与实验结果吻合.     

Intelligent prediction model of matte grade in copper flash smelting process

Due to the importance of detecting the matte grade in the copper flash smelting process, the mechanism model was established according to the multi-phase and multi-component mathematic model. Meanwhile this procedure was a complicated production process with characteristics of large time delay, nonlinearity and so on. A fuzzy neural network model was set up through a great deal of production data. Besides a novel constrained gradient descent algorithm used to update the parameters was put forward to improve the parameters learning efficiency. Ultimately the self-adaptive combination technology was adopted to paralleled integrate two models in order to obtain the prediction model of the matte grade. Industrial data validation shows that the intelligently integrated model is more precise than a single model. It can not only predict the matte grade exactly but also provide optimal control of the copper flash smelting process with potent guidance.     

Structure and properties of cathodic vacuum arc deposited NbN and NbN-based multi-component and multi-layer coatings

Binary Nb-N coatings, ternary Ti-Nb-N and Zr-Nb-N, and multi-layer TiN/NbN coatings consisting of up to 100 alternating TiN and NbN layers, were deposited onto WC-Co substrates, using two different vacuum arc deposition (VAD) systems: with and without magnetic guiding of the metal plasma flow. Binary Nb-N coatings were fabricated by deposition of metal plasma produced by a Nb cathode in a background of reactive nitrogen gas at different pressures, P. Ternary coatings were fabricated at co-deposition of plasmas originating from two different cathode materials. Multilayer coatings were fabricated by alternatively depositing plasmas of Ti and Nb in reactive nitrogen gas. The crystalline coating structure, phase composition, hardness and critical load for coating failure were studied.For binary Nb-N coatings fabricated using both deposition systems, the phase composition, the Vickers hardness, HV, and the critical load strongly depended on the deposition pressure. Using VAD with magnetic plasma guiding, the highest HV of ∼ 42 GPa was measured for coatings deposited at low nitrogen pressure. These coatings contained a hexagonal β-Nb₂N phase and had a relatively low critical load. The highest critical load and HV ∼ 38 GPa were obtained for coatings consisted of a single phase NaCl-type cubic δ-NbN structure, deposited at a higher nitrogen pressure. The structure and properties of Nb-N coatings deposited using VAD without magnetic plasma guiding had a similar correlation with the deposition pressure, however, their hardness values were lower.Ternary Ti-Nb-N and Zr-Nb-N coatings fabricated by both deposition processes had a single phase cubic NaCl-type structure and the hardness higher than that of the binary nitrides TiN, ZrN and NbN. The hardest coatings, HV ∼ 51.5 Pa, deposited with magnetic plasma guiding had a single-phase cubic δ-(Ti,Nb)N structure and a Ti:Nb ratio of ∼ 50:50 (at.%).Multilayer coatings TiN/NbN consisting of 20-40 alternating TiN and NbN layers with total thickness of 4-5 μm increased the life time of cemented carbide cutting inserts at turning tough Ni-base alloys by 2-7 times relative to uncoated cutting tools, while conventional vacuum arc deposited TiN coatings were not effective in machining of these alloys.