Accelerated wear testing with a microfabricated surface to evaluate the lubrication ability of biomolecules on polyethylene

Wear of ultrahigh‐molecular‐weight polyethylene (UHMWPE) and wear‐particle‐induced osteolysis and bone resorption are the major factors causing the failure of total joint replacements. It is feasible to improve the lubrication and reduce the wear of artificial joints. We need further understanding of the lubrication mechanism of the synovial fluid. The objective of this study is to evaluate the lubricating ability of three major components in the synovial fluid: albumin, globulin, and phospholipids. An accelerated wear testing procedure in which UHMWPE is rubbed against a microfabricated surface with controlled asperities has been developed to evaluate the lubrication behavior. An analysis of the wear particle dimensions and wear amount of the tests has provided insights for comparing their lubrication performance. It is concluded that the presence of biomolecules at the articulating interface may reduce friction. A higher concentration of a biological lubricant leads to a decrease in the wear particle width. In addition, in combination with the wear results and mechanical analysis, the roles of individual biomolecules contributing to friction and wear at the articulating interface are discussed. These results can help us to identify the role of the biomolecules in the boundary lubrication of artificial joints, and further development of lubricating additives for artificial joints may be feasible. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

橡胶Mooney—Rivlin模型材料系数对轴向刚度影响分析

在橡胶小变形范围内，采用理论推断的方法，得到在相同硬度下橡胶Mooney—Rivlin模型材料系数由C2／C1决定的关系式。并采用ABAQUS有限元软件分析的方法，结合橡胶轴向刚度常规解，分析了C2／C1不同值对橡胶轴向刚度的影响进行，结果显示其影响呈现一定规律性。     

Formation of Self-Assembled Sidewall Nanowires on Shallow Patterned GaAs (100)

The formation of "sidewall nanowires" on shallow patterned mesa strips with a modulation depth of only 35 nm on GaAs (100) was demonstrated using molecular beam epitaxy. While self-assembled GaAs sidewall nanowire formation is observed near mesa strips running along [011], relatively thinner AlAs/GaAs layers are formed on identical mesa strips running along [01-1]. Cross-sectional atomic force microscopy (XAFM) on (011) and (01-1) and AFM on (100) are used to understand the formation of the different morphology of the nanostructures, depending on the direction of the mesas. The data indicates that anisotropic surface diffusion of adatoms, resulting from the characteristic (2times4) GaAs (100) surface reconstruction, is responsible for the sidewall nanowire formation and for the different morphology observed along different directions     

ESW激波吹灰器在余热锅炉的应用

介绍了ESW激波吹灰器的工作原理及其在茂名分公司Ⅲ套催化裂化装置余热锅炉的应用情况。应用结果表明，使用ESW激波吹灰器吹灰效果明显，吹灰后余热锅炉排烟温度可下降29℃，过热蒸汽产量增加7t/h，锅炉自产饱和蒸汽产量增加2t/h，有效提高了余热锅炉的传热效率和过热能力，节能效果显著。对应用中出现的一些问题提出了改进建议。     

除沫器自动冲洗装置的设计及应用

本文针对Ⅰ效二次蒸汽折流板式除沫器需定时冲洗的实际情况，设计了一套冲洗间隔灵活可调的自动冲洗装置，该装置结构简单、工作可靠，易于实现，有一定的实用价值。     

LY-8602系列催化剂的失活原因及对策

通过催化剂的评价及表征，对LY-8602系列催化剂在低硫裂解汽油加氢时的失活原因进行了研究，结果表明，其活性下降主要是催化剂的活性中心相Co-Mo-s遭到破坏，使催化剂表面的具有加氢活性的Mo^4 峰减小所致。采用新研制的高活性加氢催化剂LY-9702与LY-8602构成复合床催化剂，可以使加氢产品合格。     

Km高温抗蚀耐磨涂料在省煤器中的应用

锅炉省煤器磨损一直是困绕锅炉稳定运行的主要因素之一。本介绍了Km高温抗蚀耐磨涂料的性能、特点，以及在实际生产中的使用情况，通过实践充分肯定了Km高温抗蚀耐磨涂料的可行性、可靠性和经济性。     

Stability analysis of regional and national voting schemes by a continuous model

The previous discrete-model-based stability analysis of regional and national voting has been extended to a continuous-model-based analysis in the simultaneous presence of white and concentrated components of noise, reconfirming the previous conclusion that regional voting with smaller sized regions always demonstrates an improved stability over those with larger sized regions, including the national voting in its limiting case in particular. The conclusion remains valid as long as the weak distribution assumption is valid.     

Stability of Mixtoxantrone Hydrochloride in Solution

A stability-indicating reversed-phase high performance liquid chromatographic method was developed for the detection of mitoxantrone HC1 and its degradation products under accelerated degradation conditions. The degradation kinetics of mitoxantrone HC1 in aqueous solution over a pH range of 1.18 to 7.20 and its stability in propylene glycol-or polyethylene glycol 400-based solutions were investigated. The observed rate constants were shown to follow apparent first-order kinetics in all cases. The pH-rate profile shows that maximum stability of mitoxantrone HC1 was obtained at pH 4.01. No general acid or base catalysis from acetate or phosphate buffer species was observed. The catalysis rate constants on the protonated mitoxantrone imposed by hydrogen ion water and hydroxy ion were determined to be 3.72 × 10 min^-1 5.64 × 10-min^-1 and 1.108 × 10^-2min^-1, respectively. The degradation rate constants of mitoxantrone affected by different ionic strength systems. Irradiation with 254 nm UV light at 25±0.5°C was found when canpared with the light-protected controls. Incorporation of nonaqueous propylene glycol or polyethylene glycol in the pH 4.01 mitoxantrone solution shows an increase in its stability at 502±0.5°C.