F_ε-I类凸半无限规划的最优性

基于I类凸函数和F凸函数,首次引入了Fε-I类凸、拟Fε-I类凸、伪Fε-I类等新广义凸性概念,研究涉及这类函数的一类半无限规划的最优性,得到一些最优性的充分条件,这些结果推广了现有某些结果,为解决某些实际问题提供了依据,也为理论上研究半无限规划提供了参考.     

Synthesis and characterization of polyimide/polyhedral oligomeric silsesquioxane nanocomposites containing quinolyl moiety

A series of functional polyhedral oligomeric silsesquioxane (POSS)/polyimide (PI) nanocomposites were prepared using a two‐step approach. First, octa(aminophenyl)silsesquioxane (OAPS) was mixed with poly(amic acid) (PAA) prepared by reacting bis(4‐amino‐3,5‐dimethylphenyl)‐3‐quinolylmethane and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride. Second, the resulting solution was subjected to thermal imidization. The well‐defined ‘hard particles’ (POSS) and the strong covalent bonds in the amide linkage between the carbon atom of the carboxyl side group in PAA and the nitrogen atom of the amino group in POSS lead to a significant improvement in the thermal and mechanical properties. Homogeneous dispersion of POSS cages in the PI is evident from scanning electron microscopy, which further confirms that the POSS molecule becomes an integral part of the organic‐inorganic inter‐crosslinked network system. Differential scanning calorimetry and dynamic mechanical analysis show that the glass transition temperatures of the POSS‐containing nanocomposites are higher than that of the corresponding neat PI system, owing to the significant increase of the crosslinking density in the PI/POSS nanocomposites. Increasing the concentration of OAPS in the PI networks decreases the dielectric constant. Pure PI and PI/POSS systems have good antimicrobial activity. Copyright © 2011 Society of Chemical Industry     

Synthesis and gas permeability of ABA‐type triblock copolymers derived from fluorine‐containing polyimide with polyhedral oligomeric silsesquioxane

ABA‐type triblock copolymers derived from 4,4'‐(hexafluoroisopropylidene)diphthalicanhydride‐2,3,5,6‐tetramethyl‐1,4‐phenylenediamine (6FDA‐TeMPD) and methacryl phenyl polyhedral oligomeric silsesquioxane (MPPOSS) were synthesized by atom transfer radical polymerization. The chemical structure of the synthesized ABA‐type triblock copolymer was confirmed by ¹H NMR, ¹³C NMR, ²⁹Si NMR and Fourier transform infrared analyses. The ratios of 6FDA‐TeMPD and MPPOSS determined by TGA were 94/6, 85/15, 77/23, 68/32, 57/43 and 31/69. The film density of the ABA‐type triblock copolymer films did not conform to the mixing rule because of polyimide (PI) chain aggregation. Based on contact angle and water uptake analyses, the hydrophobicity of the ABA‐type triblock copolymer film was determined to be higher than the theoretical value because of POSS cage effects and PI chain aggregation. The gas permeability coefficient of the ABA‐type triblock copolymer decreased compared with that of PI because of aggregation of PI chains and inhibition of solubility decreases by substitutes with high affinity. ABA‐type triblock copolymer CO₂/H₂ separation performance increased compared with that of PI. The ABA‐type triblock copolymer derived from PI and MPPOSS can be described as a polymer material with higher hydrophobicity and higher CO₂/H₂ selectivity than PI. © 2015 Society of Chemical Industry     

POSS/PA66纳米复合纤维的制备及性能研究

以间氯过氧苯甲酸与八乙烯基笼形倍半硅氧烷（POSS）反应制得的八乙烯基POSS环氧化产物为原料,采用熔融纺丝工艺制备POSS/PA66纳米复合纤维,借助FTIR、TG、FE-SEM和DSC测试方法对八乙烯基POSS环氧化产物和POSS/PA66纳米复合纤维进行表征。结果表明：将间氯过氧苯甲酸与八乙烯基POSS进行反应,可以使部分乙烯基团发生环氧化反应,生成的八乙烯基POSS环氧化产物具有良好的耐热性能。采用熔融纺丝工艺制备的POSS/PA66纳米复合纤维,POSS均匀分散在复合纤维中,纤维的热性能如熔融温度和起始分解温度都有所提高,同时纤维的力学性能也得到改善。     

广义凸向量最优化问题的对偶理论

本文利用 Hanson-Mond 的一般广义凸性条件,在任意维实赋范线性空间建立了向量最优化问题的对偶理论。     

Liquid polyoctahedral silsesquioxanes as an effective and facile reinforcement for liquid silicone rubber

Acrylo polyoctahedral silsesquioxanes (POSS), a liquid POSS derivative with reactive C=C double bond, is used to modify addition-cured liquid silicone rubber (LSR) as an effective nanofiller for the first time. Significant enhancements on mechanical properties are obtained. With addition of only 1.5 parts per hundred rubbers (phr) of acrylo POSS to fumed silica-strengthened silicones, the Young's modulus and ultimate tensile strength are increased by 432% and 66%, respectively, and the hardness of resulting LSR composites is improved as well. Proton nuclear magnetic resonance and Fourier transform infrared spectroscopies prove the efficient hydrosilylation between Acrylo POSS and hydrosiloxane directly. The thermal stability and morphology investigations also confirm that POSS is covalently incorporated into the network of silicone rubber. The increment of crosslink density is proved by extraction and swelling experiment and dynamic mechanical analysis. It can be envisioned that this simple and effective method could help produce high performance silicone rubber composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46996.     

聚多巴胺/海藻酸钠在昆虫病毒制剂上的应用

为提高甜菜夜蛾核型多角体病毒(SeNPV)抗紫外线和耐高温活性,采用雾化凝固法制备了包埋甜菜夜蛾核型多角体病毒的海藻酸钠(SA)微胶珠,通过聚多巴胺(PDA)覆膜对其进行功能化改性,制得包埋病毒的聚多巴胺/海藻酸钠微胶珠(PDA/SA-NPV)。采用FTIR、DSC、TGA、SEM、激光粒度分析仪对复合微胶珠进行表征。结果表明:制备的PDA/SA-NPV(P/S-N)微胶珠粒径(D₅₀)为132μm,其能够减缓300℃以上高温条件下的分解速度;经紫外照射处理后复合微胶珠的杀虫活性高于病毒悬浮液,表明在海藻酸钠和聚多巴胺双重保护下,病毒的抗紫外线性能增强。     

Surface-initiated RAFT polymerization of p (MA POSS-co-DMAEMA+) brushes on PDMS for improving antiadhesive and antibacterial properties

Poly (dimethylsiloxane) (PDMS) silicones, as a common intraocular lenses material, often lead to the happen of posterior capsule opacification due to the adhesion and reproduction of residual human lens epithelial cells (HLECs) on the posterior capsule after surgery. Bacterial infection is a potentially catastrophic complication of cataract surgery, which occurs within several days after implantation of the lens. A novel poly (methacrylisobutyl polyhedral oligomeric silsesquioxane-co-2-(dimethylamino)-ethyl methacrylate) (p (MA POSS-co-DMAEMA)) brush was synthesized by reversible addition–fragmentation chain-transfer (RAFT) polymerization. After being quaternized treatment by 1-bromo-heptane, p (MA POSS-co-DMAEMA⁺) brushes with bactericidal function were obtained. The optical transmission of the brushes functionalized PDMS was better than p (DMAEMA⁺) coating modified PDMS, which may be due to the similar chemical composition of MA POSS and PDMS. Measurements of water contact angle, spectroscopic ellipsometry, and atomic force microscope were used to characterize hydrophilicity, thickness, and morphology of the brushes. Results revealed that brushes rendered PDMS surface more hydrophilicity and higher roughness. Adherences of bovine serum albumin and HLECs on the p (MA POSS-co-DMAEMA⁺) brushes were significantly reduced due to the hydrophilic property and cytotoxicity of the brushes. Bactericidal activity of the brushes, measured by shake-flask culture and LIVE/DEAD bacterial viability kit staining methods, was remarkably effective against S. aureus owing to the component of p (DMAEMA⁺).     

简单多边形凸凹性自识别算法

提出一种基于极值顶点构造凸多边形和矢量叉乘的自动识别简单多边形方向性，凸凹性的算法，该算法在稳定性方面采取了有效的措施，避免因极值顶点的奇异性而导致多边形方向性，凸凹性的错误识别，具有良好的可靠性和稳定性，算法原理直观简单，效率高，时间复杂度为O（n).     

一类非线性大系统递阶优化的神经网络方法*

本文给出了一种求解一类非线性大系统递阶优化问题的神经网络模型，克服了非线性大系统优化中的对偶间隙与不可分性问题，并且该神经网络具有全集成化的特点，易于硬件实现，其协调网络和局部优化网络同步工作，具有很高的求解效率，适宜于系统实时优化应用。