基于局部均值分解与形态谱的旋转机械故障诊断方法

针对旋转机械不同类型故障会使振动信号具有不同形态特征及振动信号信噪比低等特点,提出基于局部均值分解（Local Mean Decomposition,LMD）与形态谱的旋转机械故障诊断方法。其中的LMD能对旋转机械原始振动信号进行降噪处理,而形态谱则能反映振动信号的形态特征,从而能判断旋转机械的工作状态。将该方法用于转子系统故障诊断,分析结果表明,该方法能有效提取旋转机械故障振动信号的故障特征,能准确识别旋转机械的故障状态。     

蓖麻油多元醇在聚氨酯阻燃硬泡中的应用研究

通过蓖麻油与甘油进行酯交换反应制备蓖麻油多元醇,并应用于聚氨酯阻燃硬泡的制备,研究了阻燃剂类型、添加量及蓖麻油多元醇的添加量对聚氨酯硬质泡沫（RPUF）综合性能的影响。结果表明,蓖麻油多元醇的添加量对阻燃RPUF氧指数影响不大,只是添加量大于50％时会导致泡沫收缩：添加不同阻燃剂后发现甲基磷酸二甲酯（DMMP）的阻燃效果好,DMMP合适用量为多元醇组分的20％～30％。     

基于RBF网络模型气辅成型工艺参数的优化

针对气辅成型过程中多个工艺参数的优化配置问题,提出了气辅成型工艺参数径向基函数(RBF)网络预测模型。该模型基于均匀设计思想,以RBF网络为基础,用正交最小二乘训练法对基函数的中心、方差和RBF网络权值进行优化,提高了网络预测模型对气辅成型制品质量指标的预测可靠性。以挂式空调前面板为例,对其进行CAE仿真分析,结果表明,该优化模型可实现对制品质量指标的快速预测,为工艺参数进一步优化奠定了基础。     

拉挤型FRP管轴向压缩承载性能研究

针对单向纤维增强树脂基复合材料(FRP)压缩强度远低于其拉伸强度的问题,对影响拉挤FRP管轴向压缩承载力的一些因素进行研究,探讨提高拉挤FRP管轴向压缩强度的途径。结果表明,无端部约束情况下增加包裹对提高FRP管承载力效果不明显;端部约束可改变FRP管破坏形式,对提高其承载力效果显著;在端部约束情况下增加包裹也可有效提高FRP管承载力。     

Surface chemistry and adsorption mechanism of cadmium ion on activated carbon derived from Garcinia mangostana shell

A detailed surface characterizations and adsorption mechanism of Cd²⁺ on chemical activated carbon (CAC) prepared from Garnicia mangostana shell were investigated. The activation is accomplished in self-generating atmosphere using phosphoric acid as activating agent. The characterizations performed are elemental analysis, functional group identification, N₂ adsorption isotherm and surface charges. Adsorption mechanism of metal ion was tested using Cd²⁺ as model ion. CAC achieved BET surface area of 1,498 m²/g with a mixture of micro and mesopores. The point of zero charge is observed to be at pH 2.8 and the optimum pH for Cd²⁺ adsorption on CAC is 12. The adsorption isotherm followed the Freundlich model, and the adsorption kinetics was explained by pseudo-second order kinetic model. From thermodynamic studies, the adsorption was found to be physical adsorption. X-ray photoelectron spectroscopy (XPS) confirmed the adsorption of Cd²⁺ onto CAC as +2 oxidation state.     

从某化工公司现状初探化工企业人才流失控制管理

以上海天原集团胜德塑料有限公司(SD)为研究对象,根据详实的资料分析和数据信息,结合现代企业人力资源管理理念,对公司存在的人才流失原因进行分析和研究,进而提出改进建议和方案。目的在于帮助企业实施必要的控制措施和管理制度,改善人力资源管理中的不足,提高竞争能力,确保企业持续快速发展。     

抗紫外线硅丙乳液的合成及其在外墙仿砖涂料中的应用

添加2-羟基-4-丙烯氧基二苯甲酮到硅丙乳液,制得抗紫外线硅丙乳液。考察了乳液的防晒指数(SPF值)和2-羟基-4-丙烯氧基二苯甲酮用量的关系。通过耐水性考察,确定了2-羟基-4-丙烯氧基二苯甲酮的最佳用量。实验结果表明:硅丙乳液的抗紫外线能力随着2-羟基-4-丙烯氧基二苯甲酮用量的增加而增强,2-羟基-4-丙烯氧基二苯甲酮的最佳用量为3%。用制备的抗紫外线硅丙乳液配制外墙仿砖涂料,根据JG/T 24—2000《合成树脂乳液砂壁状建筑涂料》标准检测所配制外墙仿砖涂料的相关性能,检测结果表明:制得的外墙仿砖涂料性能优良。     

Electrochemical properties of poly(4,4′-diaminodiphenyl sulfone) as a cathode material of lithium secondary batteries

Doped poly(4,4′-diaminodiphenyl sulfone) (pDDS) is prepared for use as a cathode-active material of lithium secondary batteries by chemical oxidation method using ammonium persulfate initiator. The synthesized pDDS and doped pDDS are characterized by chemical structure analysis using Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Cyclic voltammetry shows that the doped pDDS has a typical pair of redox peaks at 3.75/3.15 V vs. Li/Li⁺, corresponding to charging/discharging of the lithium ion. The discharge capacity at low current rate (0.05 C-rate) achieves 31.5 and 24.3 mA h g^?1 in the initial and 50th cycles, respectively. The doped pDDS also shows good cycle performance and high-rate capability, making it appropriate as a cathode material of lithium secondary batteries.     

Preparation and electrical properties of metal sulfides–amidoximated PAN composite film

To improve the electrical conductivity of polyacrylonitrile (PAN) film, metallic sulfides and PAN composite film were prepared by the chelating method. Dense PAN film and porous PAN film were prepared by dry process and wet process, respectively. These PAN films were treated to NH₂OH solution to introduce the amidoxime group coordinated with metallic ion. Cu⁺² and Cd⁺² ions were adsorbed to amidoximated PAN films, the sulfur ion was treated with metal-adsorbed PAN films, and thus CuS—and CdS–PAN composite films were prepared. The adsorptive capacity of amidoximated PAN film for the Cu⁺² ion was independent of the morphology of the PAN film, but the adsorptive capacity of the Cd⁺² ion on amidoximated PAN film was dependent on porosity of the polymer. Adsorptive capacity of amidoximated porous PAN film for Cd⁺² was improved about four times than that of amidoximated dense PAN film. The electrical conductivities of CuS–dense and porous PAN composite film were both 10^?1 S/cm in optimum condition, but because of the difference in adsorptive capacity, the electrical conductivities of CdS–dense and CdS–porous PAN composite films were 10^?9 S/cm and 10^?4 S/cm, respectively. Additionally, because CdS was known as a photoconductive material, the photoconductive properties of CdS–porous PAN composite film were investigated.     

汽车动力性能检测方法研究

汽车动力性能检测通常采用检测底盘输出功率然后凭经验考虑传动系损耗的检测方法。本文设计了一种改进的汽车动力性能检测方法，包括了对传动系损耗的检测。通过大量检测实践证明这是一种准确、可靠、先进的检测方法。