Since the fouling-releasing ability of silicone elastomers increased as their modulus decreases, we designed and prepared composites with embedded tiny NaC1 crytals that were soluble after their immersion in water, re...Since the fouling-releasing ability of silicone elastomers increased as their modulus decreases, we designed and prepared composites with embedded tiny NaC1 crytals that were soluble after their immersion in water, resulting in water-filled porous elastomers. The scanning electron microscope images confirmed such a designed water-filling porous structure. The existence of many micro-drops of water in these specially designed elastomers decreased the shear storage modulus and increased the loss factors. The decrease of shear modulus plays a leading role here and is directly related to a lower critical peeling-off stress of a pseudo-barnacle on them. Therefore, such a novel preparation with cheap salts instead of an expensive silicone provides a better way to make fouling-release paints with a lower modulus, a lower critical peeling-off stress and a better fouling-release property without a significant decrease of the cross-linking density.展开更多
Structure of a rotor and other design parameters are all viewed as constant using finite element software to analyze reliability of the rotor. In this case,reliability analysis of the rotor can't be realized for d...Structure of a rotor and other design parameters are all viewed as constant using finite element software to analyze reliability of the rotor. In this case,reliability analysis of the rotor can't be realized for design parameters as random. Based on theory of elastic mechanics,starting with the micro element of the rotor,stress formulas on arbitrary point of turbine disc with equal and variable thickness are deducted under the influence of centrifugal force and temperature field on rotor system simultaneously. Considering the random of structural size of the turbine rotor,temperature stress,rotating speed,external loads and material strength,the reliability of a rotor is studied with stress-strength interference model,integral stochastic finite element method(ISFEM) and Gram-Charlier series method,and random structural reliability of the rotor is computed with higher accuracy.展开更多
文摘Since the fouling-releasing ability of silicone elastomers increased as their modulus decreases, we designed and prepared composites with embedded tiny NaC1 crytals that were soluble after their immersion in water, resulting in water-filled porous elastomers. The scanning electron microscope images confirmed such a designed water-filling porous structure. The existence of many micro-drops of water in these specially designed elastomers decreased the shear storage modulus and increased the loss factors. The decrease of shear modulus plays a leading role here and is directly related to a lower critical peeling-off stress of a pseudo-barnacle on them. Therefore, such a novel preparation with cheap salts instead of an expensive silicone provides a better way to make fouling-release paints with a lower modulus, a lower critical peeling-off stress and a better fouling-release property without a significant decrease of the cross-linking density.
基金Chinese National High-tech Research Proceeding Plan(2007AA04Z442)The Major Project of Chinese National Natural Science Foundation (No. 50875039)
文摘Structure of a rotor and other design parameters are all viewed as constant using finite element software to analyze reliability of the rotor. In this case,reliability analysis of the rotor can't be realized for design parameters as random. Based on theory of elastic mechanics,starting with the micro element of the rotor,stress formulas on arbitrary point of turbine disc with equal and variable thickness are deducted under the influence of centrifugal force and temperature field on rotor system simultaneously. Considering the random of structural size of the turbine rotor,temperature stress,rotating speed,external loads and material strength,the reliability of a rotor is studied with stress-strength interference model,integral stochastic finite element method(ISFEM) and Gram-Charlier series method,and random structural reliability of the rotor is computed with higher accuracy.
