PM/PMC模式与常用项目管理模式的对比

将PM/PMC模式与常用的项目管理模式从六个方面进行了对比,并在我国的法律制度下将PM/PMC模式与监理制度进行对比,有利于选择适用的项目管理模式。     

使用PMC轴功能实现对加工中心刀库的控制

本文主要分析了PMC轴的控制原理，并从实践的角度分析在加工中心刀库控制中，利用PMC轴控制的思路和控制方案。     

海外管道工程PMC项目管理理念与实践

目前,中国石油天然气集团公司已在国外投资建成多条油气长输管道,在非洲和中亚地区还有在建管道工程。这些管道工程在建设过程中很多采用了PMC管理模式。结合海外管道工程PMC管理的实际,论述了PMC的核心价值和作用,并从PMC团队的职能定位、PMC管理成功的基石、实现PMC管理价值的法宝和PMC项目管理的首要任务等方面,探讨了PMC项目管理的理念。指出了我国目前PMC管理中存在的问题,并提出了规范PMC管理,促进PMC持续、健康发展的建议。     

基于数控铣床加装刀库的技术研究

早期的数控铣床由于不能自动换刀,一把刀加工完成后,需要人参与,把主轴上的刀卸下来,再将下把需要加工用的刀装上去,再去对刀,再调用相关程序继续加工……这样,不仅提高了人的工作强度,加大了出错的几率,而且更严重影响了加工效率。给数控铣床加装自动换刀装置,换刀动作自动完成,效率高,稳定性好,在许多企业得到了应用。从一台数控铣床着手,从硬件准备、机械安装、电路设计、NC和PMC程序编制等方面完整说明一台数控铣床加装刀库的过程。     

硅丙乳液对水泥砂浆性能的影响

在普通水泥砂浆中加入硅丙乳液配制成聚合物改性水泥砂浆(PMC)，并对其性能和微观结构进行了研究．结果表明，选择适当的聚灰比，可使PMC的综合性能得到明显改善．     

Scattering by a perfect electromagnetic conductor (PEMC) plate embedded in lossy medium

In this article, we develop an analytic theory for a perfect electromagnetic conductor (PEMC) plate embedded in lossy medium. The duality transformation introduced by Lindell and Sihvola is applied to study the electromagnetic wave scattering by a PEMC plate. Perfect electric conductor and perfect magnetic conductor are the limiting cases of PEMC media. Here, we study monoscattering by PEMC plate embedded in four different soil models. Numerical results are discussed and compared with the available literature.     

高炉使用含PMC矿炉料的配矿结构研究

通过实验室模拟高炉内矿石的熔滴过程,对含PMC矿粉的烧结矿、球团矿与南非块矿搭配的炉料结构进行了研究.研究发现,烧结矿+球团矿的炉料结构模式的熔滴性能优于烧结矿+球团矿+块矿的炉料结构模式.其中,在6#方案65%烧结矿+35%球团矿的配比下,△Tds(熔融区间)值为132℃,△Pmax(最大压差)为4.990kPa,S(总特性值)为296kPa·℃,是6个方案中熔滴性能最优的方案.炉料中的碱金属是造成炉料透气性变差的主要原因,表现为S值随着碱金属负荷的增加而升高.增加炉料中以PMC为主的球团矿可以降低炉料的碱金属负荷,从而改善炉料的熔滴特性.     

聚合物基复合材料加速老化方法研究进展

概述了聚合物基复合材料加速老化研究方法的进展,从试验方法、老化机理等方面着重介绍了湿热老化、腐蚀侵蚀和人工气候老化,总结了高置信度、高可靠度评估复合材料工作寿命的方法,并展望了复合材料加速老化研究方法.     

FANUC系统数控机床调试方法的改进与应用

以刀库加工中心为平台介绍了PMC程序的设计与调试过程,并从切换轴急停信号、卸刀手状态指示器调试及旋转轴位置检测调试3方面,对斗笠式牛刀FANUS系统的操作方法和调试过程进行了论述,指出了PMC对于数控机床调试具有的机床运行稳定、调试方便作用,并提高了工作效率。     

Multi-scale numerical simulations of thermal expansion properties of CNT-reinforced nanocomposites

In this work, the thermal expansion properties of carbon nanotube (CNT)-reinforced nanocomposites with CNT content ranging from 1 to 15 wt% were evaluated using a multi-scale numerical approach, in which the effects of two parameters, i.e., temperature and CNT content, were investigated extensively. For all CNT contents, the obtained results clearly revealed that within a wide low-temperature range (30°C ~ 62°C), thermal contraction is observed, while thermal expansion occurs in a high-temperature range (62°C ~ 120°C). It was found that at any specified CNT content, the thermal expansion properties vary with temperature - as temperature increases, the thermal expansion rate increases linearly. However, at a specified temperature, the absolute value of the thermal expansion rate decreases nonlinearly as the CNT content increases. Moreover, the results provided by the present multi-scale numerical model were in good agreement with those obtained from the corresponding theoretical analyses and experimental measurements in this work, which indicates that this multi-scale numerical approach provides a powerful tool to evaluate the thermal expansion properties of any type of CNT/polymer nanocomposites and therefore promotes the understanding on the thermal behaviors of CNT/polymer nanocomposites for their applications in temperature sensors, nanoelectronics devices, etc.