轴流风机不平衡故障诊断与平衡技术应用研究

探讨了轴流风机不平衡故障诊断与平衡技术的应用研究,通过对现场3#机轴系振动的治理,揭示了导致3#机组振动的主要原因是汽轮机转子存在较大的两阶不平衡分量,通过对汽轮机转子施加反对称分量将轴流风机轴系振动处理达到振动优良等级.     

非稳态工况下组合式空调机组性能的数值模拟

目前对组合式空调机组性能的研究多为稳态运行工况下机组性能的实验研究,研究具有单一性;另一方面,目前对机组在非稳态运行工况下性能的研究比较少.本文采用数值模拟的方法,较为详细的分析了从开机运行到最终稳定过程中机组的性能参数变化情况,得到一些可用来指导空调机组运行调节的参考数据和研究方法.     

Effect of heat-treatment on LaNiO3 film electrode of PZT thin films derived by a sol–gel method

Lanthanum nickel oxide (LaNiO₃ or LNO) conducting thin films that could be used as electrodes for improving fatigue and aging properties of ferroelectric thin films were investigated. In this paper, LNO films were directly spin-coated onto SiO₂/Si(1 0 0) substrates followed by thermal treatment in air and in oxygen. It was found that crack-free dense and uniform films with good crystallinity and medium grains were obtained, preferentially (1 0 0)-oriented LNO thin films could be formed at a lower annealing temperature of 550 °C and that with the increase in thermal annealing temperature the LNO thin film possessed better electrical properties especially at 750 °C. However, the LNO film displayed a structure transformation above 850 °C. A phenomenon was found that the first heat-treatment temperature and time played a key role to determine the crystallite size of LNO films. A subsequent deposition of a sol–gel derived Pb(Zr_0.53Ti_0.47)O₃ (PZT53/47) thin film on the LNO-coated SiO₂/Si(1 0 0) substrates was also found to have a (1 0 0)-oriented texture. Moreover, the Au/PZT/LNO capacitor was found to significantly improve the fatigue and the effects of the LNO electrodes to the fatigue were discussed.     

干熄焦旋转焦罐车设计中的几个问题

对干熄焦旋转焦罐车的开门机构、传动机构、定位机构、材料等设计问题进行了分析 ,探讨了解决的方法 ,提出了设计思路     

Si衬底上SrMnO3缓冲层对La0.8Sr0.2MnO3薄膜择优取向生长的影响

利用磁控溅射方法在(100)Si衬底上首先生长SrMnO3(SMO)作为缓冲层，再沉积得到了(110)择优取向生长的La08Sr02Mn03(LsMO)薄膜。利用X射线衍射仪分析了SMO缓冲层的结构特征对LSMO薄膜择优取向生长的影响。结果表明：当沉积温度为600℃时，增加缓冲层SMO的厚度，LSMO薄膜的取向性变好；当缓冲层SMO厚度为45nm时，LSMO薄膜基本具有(110)取向生长的特征。进一步的工作证实：提高沉积温度，能够显著增加SMO缓冲层的晶粒大小，并减少LSMO薄膜择优取向生长所需的缓冲层厚度；当沉积温度为800℃时，由于类退火作用的存在，厚度为10nm的SMO缓冲层就可以实现LSMO薄膜择优取向的生长。     

Electrical properties of Pb(Mg1/3Nb2/3)O3-PbTiO3 ceramics modified with WO3

Ferroelectrics 0.67Pb (Mg_1/3Nb_2/3)O₃-0.33PbTiO₃ (PMN-PT) + x mol% WO₃ (x=0.1, 0.5, 1, 2) were prepared by columbite precursor method. Electrical properties of WO₃-modified ferroelectrics were investigated. X-ray diffraction (XRD) was used to identify crystal structure, and pyrochlore phase were observed in 0.67Pb (Mg_1/3Nb_2/3)O₃-0.33PbTiO₃+2 mol% WO₃. Dielectric peak temperature decreased with WO₃ doping, indicating that W⁶⁺ incorporated into PMN-PT lattice. Lattice constant, pyrochlore phase and grain size contribute to the variation of K_max. Both piezoelectric constant (d₃₃) and electromechanical coupling factors (k_p) were enhanced by doping 0.1 mol% WO₃, which results from the introduction of “soft” characteristics into PMN-PT, while further WO₃ addition was detrimental. We consider that the two factors, introduction of “soft” characteristics and the formation of pyrochlore phase, appear to act together to cause the variation of piezoelectric properties of 0.67PMN-0.33PT ceramics doping with WO₃.     

电弧炉用替代废钢的金属炉料的进展

直接还原铁、铁水、冷生铁、脱碳粒铁、碳化铁、复合金属料等替代部分废钢作为电弧炉金属炉料，不仅可解决目前废钢供应短缺，也有利于稀释废钢中有害残余元素，提高钢的质量，是电弧炉冶炼优质钢的必要条件。文中介绍了电弧炉用各种金属炉料的特点和使用效果。     

Basic rules for rheologic forging process of semisolid alloy

Semisolid mold forging is a major type of semisolid processing, which is different from neither traditional mold forging nor traditional permanent casting. However, processing defects are often seen in work pieces because of lacking available rules for the process design and control. Some basic rules for the process design and control, simply named the shortest flowing length, pressure filling and the minimum uplifting mold pressure, are advanced in the paper based on amount of researches and experiments. The equations to determine the major process parameters are given out such as the filling pressure, forming pressure and locking mold pressure for the process design and control. The rules and equations are experimentally proved available and applicable by several actual work pieces produced by the semisolid forging process.     

战略成本管理的利器--业务外包

本文从分析业务外包的内涵开始入手 ,阐述了其对战略成本管理的意义 ,以及实施业务外包降低成本以获取竞争优势的主要途径     

现代工程建设项目信息化管理高效性研究

充分利用信息技术来提高工程项目管理水平，是现代工程建设项目发展的必然趋势，据此，通过论述现代工程建设项目信息化管理的特点和要求，初步阐述了建立工程项目信息化管理模式的方法以及这一模式所具有的功能，进一步分析了如何有效利用信息技术使其在项目管理中体现高效性。