Elastic moduli of a liquid crystalline polymer and its in-situ composites

The elastic moduli of a liquid crystalline polyesteramide (LCP) and polycarbonate/LCP in-situ composites with 10 to 80 wt% of LCP have been measured as functions of draw ratio λ from 1 to 15 by an ultrasonic method. For the LCP, the sharp rise of the axial Young's modulus E₃ and the slight decreases of the transverse Young's modulus E₁ and the axial (C₄₄) and transverse (C₆₆) shear modulus with increasing λ result from the alignment of chains along the draw direction. E₁, C₄₄, and C₆₆ follow the lower bounds calculated using the series coupling scheme of the aggregate model. Although E₃ lies close to the lower bound at low λ, it follows the upper bound calculated according to the parallel coupling scheme at λ > 3. The elastic moduli of the composites have similar draw ratio dependences as those of the LCP. The strong increase in E₃ with increasing λ arises from the higher aspect ratio of the LCP domains in the composites and the improved molecular orientation within the domains. The reinforcement effect on the other moduli is much weaker, with E₁ and C₄₄ of the composites only 5 to 30% higher than those of polycarbonate at λ = 15. Since C₆₆ of the LCP decreases to a value below that of polycarbonate at λ > 2, there is a positive reinforcement effect at low λ but a negative effect at high λ.     

火电厂Multiagent控制系统中的优化任务分解Agents

提出了一个火电厂多代理控制系统（MACS）,并洋细介绍了其中优化任务分解代理子系统（OTDAS）的目标、决策和运行,OTDAS通过一个优化代理和一个分解代理对火电厂多代理控制系统的任务进行了优化分解。优化代理的决策采用了遗传算法（GA）,OTDAS的运行结果表明GA是Agent决策的有效工具。     

Elastic constants and thermal expansivity of gel-spun polyethylene fiber and its composites

The five independent stiffness constants, C₁₁, C₃₃, C₄₄, C₆₆, and C₁₃, and the axial and transverse thermal expansivity of unidirectional gel-spun polyethylene fiber reinforced composites have been measured as functions of fiber volume fraction V_f. The axial extensional modulus C₃₃ and axial Poisson's ratio v₁₃ follow the rule of mixtures, while the axial shear modulus C₄₄, transverse shear modulus C₆₆, and transverse plane-strain bulk modulus C_t ( = C₁₁ − C₆₆) obey the Halpin-Tsai equation. Extrapolation to V_f = 1 gives the five stiffness constants of gel-spun polyethylene fiber. The tensile property of the fiber is highly anisotropic, with the axial Young's modulus about 40 times higher than the transverse Young's modulus. In contrast, the axial shear modulus exceeds the transverse shear modulus by only 5%. A similar treatment of the thermal expansivity data in terms of the Schapery equations gives an axial thermal expansivity of −1.25 × 10⁻⁵ K⁻¹ and a transverse thermal expansivity of 11.7 × 10⁻⁵ K⁻¹ for the fiber.     

Crystallization of Bismuth Borosilicate-Based Dielectric Thick Films on a LiZn Ferrite Substrate

The compatibility and crystallization of dielectric thick films, consisting of a bismuth borosilicate glass and crystalline cordierite, on a LiZn ferrite substrate were investigated by focusing on phase development and microstructural changes. Significant diffusion of Li and Fe from the substrate to the dielectric was confirmed as unexpected crystalline phases such as Li₂Al₂Si₃O₁₀ and Fe₂O₃ were found in the thick films fired at 850°C. The crystallization was believed to be initiated from the film interface and developed further toward the film surface as evidenced from cross-sectional microstructures of the films with additional firings. The degree of crystallization and the relative contents of the observed phases were dependent on the ratio between the glass and cordierite and the number of refirings.     

High thermal conductivity of spark plasma sintered silicon carbide ceramics with yttria and scandia

A fully dense SiC ceramic with a room‐temperature thermal conductivity of 262 W·(m·K)^?1 was obtained via spark plasma sintering β‐SiC powder containing 0.79 vol% Y₂O₃‐Sc₂O₃. High‐resolution transmission electron microscopy revealed two different SiC‐SiC boundaries, that is, amorphous and clean boundaries, in addition to a fully crystallized junction phase. A high thermal conductivity was attributed to a low lattice oxygen content and the presence of clean SiC‐SiC boundaries.     

Interface characterization of Al/Cu 2-ply composites under various loading conditions

The effects of reduction ratio during roll bonding on the microstructural evolution at interface and subsequent mechanical properties of roll-bonded Al/Cu 2-ply sheets were investigated. The interface microstructures for several Al/Cu 2-ply sheets fabricated under different reduction ratios between 30% and 65% were verified by transmission electron microscopy (TEM). Taking the difference of interface microstructure into consideration, 3-point bending and peel tests were performed for obtaining flexural and bonding strengths for Al/Cu 2-ply sheets. The effect of the quantified areas of metallurgical bonding at interfaces on the bonding strength was also discussed. The results show that both the bonding and flexural strengths for Al/Cu 2-ply sheets are reduced by decreasing the reduction ratio during the roll bonding process, which is strongly correlated with the interface microstructure. This was especially verified by observing the interface delamination from the 3-point bent samples.     

Zr－Nb系合金耐蚀性能研究

结合核动力堆用燃料包壳对锆合金耐蚀性能的要求，大范围考察了Ｎｂ含量为０．５％，１．０％，２．６％（ｗｔ％）的Ｚｒ—Ｎｂ二元合金及含Ｃｒ、Ｍｏ、Ｓｎ、Ｂｉ、Ｆｅ、Ｃｅ和Ｓｉ的Ｚｒ－１Ｎｂ及多元合金，共１７种成分的Ｚｒ－Ｎｂ系合金在４００℃，１０．３ＭＰａ水蒸汽中的长期腐蚀规律（达１８２天）。在腐蚀转折前，Ｚｒ－Ｎｂ系合金的腐蚀动力学曲线均近似于抛物线规律，而在转折之后存在与线性规律偏离现象。长期腐蚀增重的分析说明：通过合理的多元合金化，即增加或降低Ｎｂ含量，并主加Ｆｅ、Ｂｉ、Ｓｎ和Ｎｉ而辅加少量的Ｃｒ、Ｍｏ、Ｔｅ和Ｓｉ，Ｚｒ－１Ｎｂ合金的耐蚀性大有潜力可挖。     

Cytotoxic Triosmium Carbonyl Clusters: A Structure–Activity Relationship Study

A structure–activity relationship (SAR) study of the triosmium carbonyl cluster Os₃(CO)₁₀(NCCH₃)₂ was carried out with a series of clusters of the general formula Os₃(CO)_12?nL_n, cationic osmium clusters and a hemi‐labile maltolato‐Os cluster. The SAR results showed that good solubility in DMSO and at least one vacant site are required for cytotoxicity. In vitro evaluation of these new compounds showed that some are selectively active against estrogen receptor (ER)‐independent MDA‐MB‐231 breast cancer cell lines relative to ER‐dependent MCF‐7 breast cancer cells, suggesting that the compounds have a different biological target specific to MDA‐MB‐231 cells. In particular, the maltolato cluster exhibits strong antiproliferative activity, with an IC₅₀ value of 3 μM after only 24 h incubation. Additionally, biochemical assays conducted with the cationic cluster show that it induces apoptosis, although a biological target has not yet been identified. Further research to establish the molecular targets of these compounds and to develop improved organometallic clusters as potential breast cancer therapeutics is underway.     

Thermal properties and adhesion strength of amorphous poly(α‐olefins)/styrene–ethylene–butylene copolymer/terpene hot‐melt adhesive

The thermal stability and adhesion properties, such as lap‐shear strength of hot‐melt adhesives were obtained from amorphous poly(α‐olefins) and thermoplastic rubber [styrene–ethylene–butylene copolymer (SEBS)] blends. The addition of SEBS increased the toughness and viscosity and decreased the lap‐shear strength of the hot‐melt adhesive. Terpene tackifier resin offered enhanced lap‐shear strength; this was more effective when combined tackifier resin was added on the hot‐melt adhesive. Only a small amount of wax and antioxidant affected the thermal stability and lap‐shear strength of the hot‐melt adhesive. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Consumer Awareness and Interest Toward Sodium Reduction Trends in Korea

Reduction of dietary sodium intake by lowering amount of sodium in foods is a global industry target. Quantitative information on current consumer knowledge of sodium reduction trends in Korea is unknown. The objective of this study was to quantify the consumer knowledge and awareness of sodium and salt reduction in foods and to characterize consumer interest in health labeling on the food package. Additionally, comparison of consumer knowledge status between Korea and United States was followed. Consumers (n = 289) participated in an internet survey designed to gauge consumer knowledge and attitudes toward dietary sodium, the sodium content in representative food products (n = 27), and their interest toward specific health claims, including sodium labeling. Questions regarding demographics as well as consumption characteristics were asked. Sodium knowledge index and saltiness belief index were calculated based on the number of correct responses regarding the salt level and sodium content in given food products. Kano analysis was conducted to determine the role of nutrition labels in consumer satisfaction with products. Current consumer knowledge on the sodium content in food products was high, and consumers were adept at matching the sodium content with the salty taste intensity of food products. Consumers’ knowledge of the relationship between diets high in sodium and an increased risk of developing previously reported sodium‐related diseases, such as hypertension, coronary heart disease, kidney disease, and stomach cancer, were also high. Information on the nutrition panel that influences the consumer satisfaction (trans‐fat, sodium, ingredient list, and country of origin) as well as adjective‐nutrition claim pairs that appeal positively to purchase intent of the product were identified.