结构形式对椭圆扁管管内传热与流阻性能影响

利用数值模拟方法结合场协同理论,对直椭圆扁管、单向螺旋椭圆扁管和变向螺旋椭圆扁管管内传热与流动情况进行了数值模拟计算和理论分析,比较研究了不同的Re、Pr下,3种椭圆扁管的管内传热与流阻特性。结果表明,单向螺旋椭圆扁管和变向螺旋椭圆扁管与直椭圆扁管相比有很好的强化传热性能,而变向螺旋椭圆扁管要比单向螺旋椭圆扁管的强化传热性能更好。在管内流体具有高Pr及低Re的条件下,2种螺旋椭圆扁管的强化传热效果显著,可作为很好的强化传热元件应用于工程实际中。     

Potential of Silver Nanoparticles in Overcoming the Intrinsic Resistance of Pseudomonas aeruginosa to Secondary Metabolites from Carnivorous Plants

Carnivorous plants are exemplary natural sources of secondary metabolites with biological activity. However, the therapeutic antimicrobial potential of these compounds is limited due to intrinsic resistance of selected bacterial pathogens, among which Pseudomonas aeruginosa represents an extreme example. The objective of the study was to overcome the intrinsic resistance of P. aeruginosa by combining silver nanoparticles (AgNPs) with secondary metabolites from selected carnivorous plant species. We employed the broth microdilution method, the checkerboard titration technique and comprehensive phytochemical analyses to define interactions between nanoparticles and active compounds from carnivorous plants. It has been confirmed that P. aeruginosa is resistant to a broad range of secondary metabolites from carnivorous plants, i.e., naphthoquinones, flavonoids, phenolic acids (MBC = 512 µg mL⁻¹) and only weakly sensitive to their mixtures, i.e., extracts and extracts’ fractions. However, it was shown that the antimicrobial activity of extracts and fractions with a significant level of naphthoquinone (plumbagin) was significantly enhanced by AgNPs. Our studies clearly demonstrated a crucial role of naphthoquinones in AgNPs and extract interaction, as well as depicted the potential of AgNPs to restore the bactericidal activity of naphthoquinones towards P. aeruginosa. Our findings indicate the significant potential of nanoparticles to modulate the activity of selected secondary metabolites and revisit their antimicrobial potential towards human pathogenic bacteria.     

Alumina-, niobia-, and niobia/alumina-supported NiMoS catalysts: Surface properties and activities in the hydrodesulfurization of thiophene and hydrodenitrogenation of 2,6-dimethylaniline

The activity of NiMoS catalysts supported on niobia, alumina, and niobia/alumina was compared for the thiophene hydrodesulfurization (HDS) and 2,6-dimethylaniline (2,6-DMA) hydrodenitrogenation (HDN) reactions. To evaluate the acidity of the supports and identify the nature of the sulfide sites, adsorption of 2,6-dimethylpyridine, pyridine, and CO was performed and followed by IR spectroscopy. This study has shown that with niobia as a support, the activity of NiMoS catalysts in thiophene HDS and in HDN of 2,6-DMA was no longer promoted by the synergy between Ni and Mo. The absence of synergy between molybdenum and nickel on niobia can be explained by the strong interaction of each metal with niobia at the expense of interaction with each other. Moreover, it has been shown that on a niobia/alumina support, the formation of the NiMoS phase can be directly linked to the presence of alumina not covered by niobia. However, niobia is an interesting support for the HDN of 2,6-DMA, because it favors the formation of xylene through direct ammonia elimination involving low H₂ consumption. The activity for xylene formation on niobia is linked to the electron-deficient nature of the Mo sulfide site, as demonstrated by CO adsorption followed by IR.     

聚乙烯复合阻燃体系的研究及应用进展

综述了近年来国内外阻燃聚乙烯（PE）用有协同作用的复合阻燃体系：（1）卤-锑体系；（2）磷-氮体系；（3）金属氧化物体系；（4）膨胀型体系；（5）其他类等5类复合阻燃体系的研究和应用情况。     

Electrical resistance behavior of vinylester composites filled with glass-carbon hybrid fibers

Vinylester (bismethacryloxy derivative of a bisphenol-A type EP resin, VE) composites with glass-carbon hybrid fibers (CF-GF) weight fraction of 50%, were prepared by the compress molding method. The distribution of carbon fiber in the hybrids was observed by stereomicroscope. The electrical resistance behavior of the composites filled with different carbon fiber (CF) weight contents (0.5% to 20%) was studied. The experimental results show that the electrical resistance behaviors of CF-GF/VE composites are different with those of CF/VE composites because carbon fibers’ conducting networks are broken by the glass fibers in the CF-GF/VE composites. The carbon fibers distribute uniformly in the networks of glass fibers (GF) like single silk and form the semi-continuous conducting networks. Composite filled with GF-CF hybrid has a higher percolation threshold than that filled with pure CF. At that time, the resistivity of CF-GF/VE composites varies little with the temperature increasing. The temperature coefficient of resistivity in GF-CF/VE composite is less than 317 ppm and the variation of the resistivity after ten thermal cycles from 20 °C to 240 °C is less than 1.96%. Funded by the Natural Science Foundation of Hubei Province (No. 2007ABA028)     

基于BIM技术的装配式建筑设计阶段协同度评估

为评估BIM技术对装配式建筑设计阶段协同能力的影响程度,基于协同论序参量原理,把软件协同、专业协同作为协同度测度模型的一级指标,在一级指标下选取22个序参量分量指标构建协同度模型。结合具体案例,以装配式建筑设计阶段为研究对象,运用专家打分法将测量指标进行更明确的量化,并借助功效函数对构建的指标体系的协同能力进行评估计算。结果表明：由于BIM软件之间数据共享与转换格式的不统一,仍出现了信息丢失、传递效率低的现象;专业协同与理想状态有一定的差距,BIM技术有待完善。     

重庆保税港区港口物流与区域经济协同发展研究

以系统协同理论为基础,以2008—2013年重庆保税港区港口物流和区域经济的相关数据为依托,构建协同度模型研究了两系统协同发展的情况。研究表明：重庆保税港区港口物流与区域经济是协同发展的,但协同发展程度整体偏低,重庆保税港区对区域经济的带动作用不强。据此,重庆保税港区应采取相关措施进一步拓展港口物流功能,促进两系统协同发展。     

基于供应链视域下的生产运营计划制订和管控研究

文章分析了当前企业生产运营计划与控制的状况,指出其在交货期控制、信息集成等方面存在的诸多问题,提出了构建基于供应链环境下的生产运营计划系统和信息平台模型。通过统一上下游资源、优化供应链流程,快速应对市场的变化;通过生产同步化,提高生产运营计划系统的柔性和灵敏性,有效降低过程运营成本,使供应链效能最大化。     

加强大学生社会主义核心价值观培育的思考——以古代中国“化民成俗”生活教化实践为视角

古代中国"化民成俗"是通过改变物质生活方式从而达到构建满足封建统治阶级意愿的社会精神秩序的生活教化实践。其体现出来生活化、渐进性、综合性的教化特征不仅是我国传统教育的要义,也是现代教育的应有之义。社会主义核心价值观作为符合中国具体国情的主流价值需要社会的接受和认同,对"化民成俗"的研究为新的社会精神秩序的构建特别是对大学生对主流价值的接受和认同提供了新的视角。在遵循大学生认知发展规律的基础上,通过与大学生生活的全面对接,实现社会主义核心价值观的协同培育。古代中国"化民成俗"生活教化实践为大学生社会主义核心价值观培育点明了思路。