VN微合金化超细晶高强钢的组织性能研究

基于电炉薄板坯连铸连轧流程氮高的特点,采用VN微合金化的成分设计,通过炼钢、连铸、均热、轧制和冷却各工艺过程的控制研究,开发了VN微合金超细晶高强钢板。钢板屈服强度达到了550MPa级,铁素体晶粒尺寸达到了3．0～4．0μm,具有良好的韧性、冷成形性能和焊接性能,满足汽车、工程机械制造等行业的要求。     

三峡水库综合利用调度关键技术研究与实践

为全面提升三峡工程的综合利用效益,三峡水库蓄水以来对规划设计的水库调度方式进行了优化研究与实践。文章对其关键技术进行分析总结,主要有协调防洪、发电、航运、供水和生态等多目标需求的技术、调度风险控制技术、调度决策优化技术、编制调度规程以规范调度工作等。通过分析以寻求不断完善三峡水库综合利用调度方式的路径,力求实现三峡工程效益最优,成为环境友好且对社会公益性贡献突出的跨世纪宏伟工程。     

美拉德反应及系列香料的合成

本文详细阐明美拉德反应的化学过程。并在此理论基础上,用多种氨基酸分别与葡萄糖在不同温度、不同时间、不同pH值及添加剂有无等条件下进行反应。由此合成了9个新的香料。这将对香料化学家提出一个重要问题——如何利用美拉德反应,在食品、烟草领域进一步开发香料新品种。     

In planta Mechanism of Action of Leptospermone: Impact of Its Physico-Chemical Properties on Uptake, Translocation, and Metabolism

Leptospermone is a natural β-triketone that specifically inhibits the enzyme p-hydrophyphenylpyruvate dioxygenase, the same molecular target site as that of the commercial herbicide mesotrione. The β-triketone-rich essential oil of Leptospermum scoparium has both preemergence and postemergence herbicidal activity, resulting in bleaching of treated plants and dramatic growth reduction. Radiolabeled leptospermone was synthesized to investigate the in planta mechanism of action of this natural herbicide. Approximately 50 % of the absorbed leptospermone was translocated to the foliage suggesting rapid acropetal movement of the molecule. On the other hand, very little leptospermone was translocated away from the point of application on the foliage, indicating poor phloem mobility. These observations are consistent with the physico-chemical properties of leptospermone, such as its experimentally measured logP and pK _a values, and molecular mass, number of hydrogen donors and acceptors, and number of rotatable bonds. Consequently, leptospermone is taken up readily by roots and translocated to reach its molecular target site. This provides additional evidence that the anecdotal observation of allelopathic suppression of plant growth under β-triketone-producing species may be due to the release of these phytotoxins in soils.     

低温煤焦油超声萃取物的组成分析

对榆林地区低温煤焦油通过超声萃取进行分离,并利用GC-MS对萃取物中的有机质进行了分析.结果表明,榆林地区低温煤焦油中芳烃总体含量最高,且芳烃组分呈现的特点是种类多,各组分含量不高;烷烃含量次之,其中多为正构烷烃,支链烷烃较少.此外还有一定量的烯烃、酚、其他含氧化合物、含氮化合物等,但这些化合物相对含量较少.     

CRITICAL FLUX DETERMINATION IN ULTRAFILTRATION OF WASTEWATER FROM A FOOD INDUSTRY BY OPTIMIZATION METHOD

Two ultrafiltration membranes with different geometries (spiral polymeric and tubular ceramic) but similar cutoffs were used to treat wastewater from a food industry. Hydrodynamic conditions were optimized by statistical methods as a strategy to get more accurate values of the critical parameters and then to produce higher water flux and minimization of membrane fouling. The validation of the optimization method was obtained by experimental critical flux determination at critical parameters. Membrane fluxes revealed significant differences during filtration. The polymeric membrane showed an optimal flux of 45.60 Lh^?1 m^?2 at 3.21 bar while operating at a stable time of 11.61 h, whereas optimal flux of the ceramic membrane was 32.43 Lh^?1 m^?2 at 3.98 bar for 16.03 h. Experimental critical flux values were only slightly lower than optimal fluxes for both membranes, showing the validity of the statistics models applied. Negligible osmotic pressure was found on the two membranes at critical flux parameters, indicating irreversible fouling for both cases. The polymeric membrane revealed strong fouling behavior and the ceramic membrane showed a weak form; the flux decline occurred first in the polymeric membrane, whereas the ceramic membrane exhibited high stability during the filtration operations. A high degree of purification of wastewater was obtained by this membrane at critical flux conditions.     

面向多级调度管理的云搜索体系架构研究

提出了一种面向大电网多级调度管理一体化的云计算搜索引擎体系架构设计方法.该方法引入云计算理念,在大电网多级调度管理一体化IT基础设施资源充分整合的基础上,通过调度数据网络将分布于各调度中心的业务数据资源进行有效组织、布局和管理,按照“需则可用”的总体思路,为调度管理等业务应用提供高效的数据共享、交互、检索等各类服务,实现“随需共享”目标,并支持数据的定制化访问和可视化展现.文中着重分析了大电网多级调度管理一体化云搜索引擎的体系架构、技术体系和应用整体设计,为基于成熟、稳定、可靠的开源搜索引擎平台研发系统原型提供理论依据.     

Characterisation of Progressive Skeletal Muscle Fibrosis in the Mdx Mouse Model of Duchenne Muscular Dystrophy: An In Vivo and In Vitro Study

Duchenne muscular dystrophy (DMD) is a rare genetic disease leading to progressive muscle wasting, respiratory failure, and cardiomyopathy. Although muscle fibrosis represents a DMD hallmark, the organisation of the extracellular matrix and the molecular changes in its turnover are still not fully understood. To define the architectural changes over time in muscle fibrosis, we used an mdx mouse model of DMD and analysed collagen and glycosaminoglycans/proteoglycans content in skeletal muscle sections at different time points during disease progression and in comparison with age-matched controls. Collagen significantly increased particularly in the diaphragm, quadriceps, and gastrocnemius in adult mdx, with fibrosis significantly correlating with muscle degeneration. We also analysed collagen turnover pathways underlying fibrosis development in cultured primary quadriceps-derived fibroblasts. Collagen secretion and matrix metalloproteinases (MMPs) remained unaffected in both young and adult mdx compared to wt fibroblasts, whereas collagen cross-linking and tissue inhibitors of MMP (TIMP) expression significantly increased. We conclude that, in the DMD model we used, fibrosis mostly affects diaphragm and quadriceps with a higher collagen cross-linking and inhibition of MMPs that contribute differently to progressive collagen accumulation during fibrotic remodelling. This study offers a comprehensive histological and molecular characterisation of DMD-associated muscle fibrosis; it may thus provide new targets for tailored therapeutic interventions.     

Biobased polyester obtained from bifunctional monomers through metathesis of fatty acids as precursor to synthesis of polyurethanes

Biobased unsaturated aliphatic polyesters and polyurethanes were obtained from fatty acid monomers with double functionality synthesized through cross-metathesis of oleic acid and oleic alcohol. The chemical structure and thermal behavior of the monomers and polymers were analyzed by several physicochemical tests, and oscillatory rheometry and optical microscopy were used to determine their rheological properties and to observe the crystal formation of the obtained polyesters, respectively. It has been found that the polyesterification reaction depends on reaction temperature and to a lesser degree on both the reaction time and catalyst addition. The melt temperature and enthalpy of the obtained biobased polymers show that the monomer chain length has an effect on both the crystallinity and thermal transitions of the polymers, as can be explained by a group contribution analysis showing excellent correlation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47095.