固定式刚性联轴器不对中弯扭耦合振动特性

以水轮发电机组固定式刚性联轴器平行不对中故障为研究对象,从动力学角度推导不对中机理,建立平行不对中弯扭耦合振动微分方程.基于该微分方程,理论上分析了弯振、扭振之间的相互影响;从转速、质量偏心、不对中量和阻尼系数等几方面进行弯扭耦合振动数值仿真.仿真计算表明:弯振与扭振通过固结于转子的偏心质量相互耦合;弯振主要包含工频成分,不对中越严重,工频所占比例越大.扭振包括极大的直流分量和少量倍频成分,过大的直流分量对机组安全不利.     

Growth of decagonal quasicrystal phase in laser resolidified Al72Ni12Co16

An ultra-high temperature gradient directional solidification process produced by a widened laser beam was adopted to achieve the directionally solidified microstructure of the stable decagonal quasicrystal phase in Al72Ni12Co16 alloy. X-ray, SEM, TEM and optical microscopy techniques were used to investigate the microstructures and identify the phase. The directionally solidified decagonal quasicrystal showed the facet morphology and grew in lateral growth mode. The unusual periodic and quasiperiodic atomic structures of the decagonal quasicrystal and the epitaxial growth in the melt pool were considered to be the key factors influencing the growth morphology. The experimental results were consistent with the Toner's theoretical atomistic growth model.     

流变铸造仪高真空密封技术研究

本文从流变冶金浆料器上高真空密封设计出发,研究设计了轴既转动又移动且在高温情况下的高真空密封装置以及轴转动且在高温情况下的高真空密封装置,探讨了所设计装置的一些流变学问题以及一些关键参数的选取,可供设计时参考。     

变幅杆横向振动的频率修正

在变幅杆有径向动能的情况下,运用能量法,给出考虑横向效应后变幅杆谐振频率的计算公式,计算结果与实验值吻合较好。     

旋转体侧面积计算的一般公式

本文给出闭区间上光滑曲线绕任一直线旋转所产生的旋转体的侧面积的一个方便实用的计算公式．     

料浆离心泵油封结构的改进及应用

针对天脊集团公司复肥厂SL—G300×250型离心式料浆泵原轴承箱压盖和转轴之间的密封结构在生产实际中存在的问题,提出了用甩水环与螺旋密封的组合密封结构替代原迷宫密封结构的改进方案,经过生产运行,达到了轴头处无任何泄漏的要求。     

The pattern of the mechanosensory lateral line on the caudal fin of the two deep‐water gobiid fishes Deltentosteus collonianus and Deltentosteus quadrimaculatus (Teleostei: Gobiidae)

The most common pattern of the lateral line system on the caudal fin of Gobiidae is characterized by three longitudinal rows of free neuromasts. Deltentosteus collonianus and Deltentosteus quadrimaculatus are two benthic Atlantic–Mediterranean gobiid fishes with additional rows on the caudal fin. In these species the caudal fin is more densely covered by the lateral line system compared to the usual status in Gobiidae. An increase of longitudinal neuromast rows occurs rarely in gobiid fishes and is only known in a few species of Gobiidae with a pelagic lifestyle. Both Deltentosteus species show numbers of neuromast rows on the caudal fin between the plesiomorphic three and the advanced eight rows of pelagic gobies. This intermediate position allows discussion of the existence and the characteristics of an underlying pattern in the increase of the number of longitudinal neuromast rows and adaptation to habitat conditions in Gobiidae.     

弹体侧向喷流流动干扰数值模拟与分析

通过求解三维N-S可压缩方程,对弹-翼组合体的侧向喷流流场进行数值模拟.研究了不同喷口位置,不同喷流压力下的干扰流场.分析了流场结构,研究了流场干扰与气动力干扰的关系.结果表明,在超音速流场中,喷口位置的不同,会带来喷流放大因子的变化.喷口位置相对于翼偏转,即喷口与翼面的夹角增大,喷流放大因子相应增加,侧向喷流的控制效果更好.     

延长油田牛平7井钻井液技术

牛平7井所在区块地层结构复杂,钻井液技术难度大。为确保该井顺利施工,针对不同井段地层岩性,使用了低固相聚合物封堵防塌钻井液体系和低固相润滑防塌钻井液体系,辅以相应的钻井液维护处理工艺和固控设备,解决了上部地层易发生漏失、安定组和直罗组易坍塌掉块、煤层段紧邻目的层易垮塌等难题,达到了优快钻井的目的,为该区块以后的钻井液施工提供了经验。     

考虑不同地区零售商间转载协作的库存模型

研究由中央仓库和分布于不同地区零售店组成的多点库存系统,同一地区库存点间允许双向转载,不同地区库存点间仅存在单向转载;库存点面临独立泊松分布需求,采用连续检查的(S-1,S)策略.基于M/G/S/S队列理论、生灭过程模型和近似计算思想,分别建立损失销售情况和延期交货情况下的库存模型.设计了该库存系统的离散事件仿真过程以获取比较标杆.设计了系统参数变化组合实验,对比分析近似模型、仿真模型、策略仿真、单向转载模型和无转载模型的计算结果,发现所提近似混合转载模型的期望总成本最小.