Employing fractals and FEM for detailed variation analysis of non-rigid assemblies

Many studies on non-rigid assemblies, or assemblies of non-rigid components, suggest that the component variation affects the assembly dimensional quality. However, little is known about how the variation of surface micro-geometry of assembly components influences the assembly dimensional quality. In this paper, a new method based on the fractal geometry and finite element method (FEM) is proposed to study such an influence. In the new method, a special fractal function, named the Weierstrass–Mandelbrot (W–M) function, is used to extract and represent the characteristics of surface micro-geometry of assembly components. FEM is applied to analyze the deformation of non-rigid assemblies by integrating the variation of component micro-geometry. The sensitivity matrix between the component variation and assembly variation is obtained by using the existing influence coefficients method. It is found that contributions of the surface micro-geometry of assembly components to the final variation of non-rigid assemblies could be substantial under certain conditions. The proposed method is illustrated through a case study on an assembly of two flat sheet metal components under different fixture-releasing conditions.     

液相还原法制备纳米银粉的研究

在液相联氨还原法工艺基础上，对液相还原法制备纳米银粉的还原反应条件（体系温度、分散剂、反应物浓度）进行了研究，得到了优化的反应条件；反应体系温度70℃，反应物浓度[Ag[NH3]2^ ]=0.02mol/l和特定的分散剂2^#。且冬季同平均粒径约为50nm、大小均匀、灰白色的球状银粉。     

山梨酸正丁酯的合成研究

以山梨酸与正丁醇为原料,对甲苯磺酸为催化剂合成了山梨酸正丁酯,用乙酸丁酯作带水剂,4A分子筛作除水剂,酯化收率可达97.5%.     

Preparation of fluoroacrylate nanocopolymer by miniemulsion polymerization used in textile finishing

Latex based on fluoroacrylate (TAN) and other comonomers was prepared via miniemulsion polymerization in the presence of stearyl trimethyl ammonium chloride (STAC) and 2, 2′‐azobis (2‐amidinopropane) dihydrochloride (ABAP) as a water soluble initiator. Light transmittance studies demonstrated that the light transmittance of prepared emulsions increases with the amount of TAN, STAC, cosolvent DPM, and hydrophobe DM. Given suitable reaction temperature and quantities of TAN, STAC, DPM, and DM, a copolymer emulsion of fluoroacylate with a particle size of 50 nm was produced. The water repellency tested on polyester fabrics displayed greater effectiveness than that of commercial products with higher fluorine content. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1466–1472, 2004     

高性能环氧树脂涂料的研制

以甲基丙烯酸、丙烯酸丁酯及苯乙烯的聚合为接枝体，在过氧化苯甲酰作用下对E-51环氧树脂进行接枝改性，同时对三乙烯四胺进行曼尼希改性，制得多种改性固化剂，并用其与改性的环氧树脂配制成涂料，实验结果表明，当苯酚、甲醛和三乙烯四胺的物质的量比为3：3：1时固化剂的固化性能最好。     

改进马蹄焰玻璃窑炉加料口设计的体会

我厂总结加料实际运行情况,分析加料口对配合料熔化作业的影响,在仍采用一台(嘴宽为800mm)毯式推料加料机情况下,对24m~2的马蹄焰熔炉加料口结构进行了改进,取得了较好的效果。     

从煤炭、天然气制取石油石化产品工艺技术

在阐述煤炭、天然气通过吹氧气化制取CO +H2 合成气联产石油石化产品的基础上 ,详细介绍了甲醇、二甲醚、乙烯生产工艺技术的应用与开发 ,对各种工艺路线进行了论证和技术经济评估     

活性炭制作研究进展

活性炭的研究非常活跃。原料的广泛性，工艺的先进性，产品性能的特殊性都受到活性炭使用者的广泛关注，特综述了近年来活性炭研制进展概况并对活性炭的研制作展望。     

钢渣、碱矿渣水泥强度影响因素的研究

本文从宏观和微观两方面,讨论了诸如钢渣（D渣）掺量、碱组分及养护条件等因素对钢渣-碱矿渣水泥强度发展的影响机理,为更好利用钢渣以作为碱矿渣水泥的复合组分,进行了理论和实践方面的探索.