HPLC法测定人工合成益母草碱有关物质

建立一种用高效液相色谱法测定合成益母草碱有关物质的方法。C18色谱柱,流动相:0.025 mol/L磷酸溶液(用三乙胺调节pH值至6.5)-甲醇(15∶85);流速0.87 mL/min;检测波长277 nm。研究显示用该HPLC方法对合成益母草碱有关物质检测具有良好的专属性,且对合成益母草碱稳定性具有良好的指示能力。     

我国核事故应急演习工作研究与建议

对2009年以来的2次国家级核应急联合演习和13次省级核事故应急联合演习的主要经验和暴露的问题进行了总结。给出了增强演习的实战性、加强技术研判和决策分析的演练、重视海上核应急演练、重视针对涉核舆情与群体恐慌的专项演练与研究的建议。     

武汉上太子溪渠道工程设计

简要介绍了武汉新区上太子溪渠道工程项目概况,详细阐述了该渠道工程的总体设计、景观设计及结构设计等相关内容,指出设计时应注意渠道的功能性、景观性和稳定性,以使工程建成后达到＂湖通景至＂的效果。     

The simulation and experimental study of glossiness formation in belt sanding and polishing processes

Glossiness is an optical index representing the capacity of a surface to reflect light, which is vital criteria for components in need of esthetic appearance. To achieve the stringent glossiness requirement, sanding and polishing for smooth surface generation become the necessary material removal method. However, the intrinsic correlation of surface roughness and glossiness is still not clear. Small roughness value does not always guarantee perfect glossiness, and high surface glossiness does not always require extreme surface roughness perfection. In this paper, the surface topography features and glossiness conditions are analyzed for sanded and polished surfaces. And the surface glossiness is modeled and simulated for surfaces generated with non-Gaussian topography features manufactured by sanding and polishing. Finally, the critical surface topography parameters are identified to establish the correlation with the surface glossiness.     

A graph coloring constructive hyper-heuristic for examination timetabling problems

In this work we investigate a new graph coloring constructive hyper-heuristic for solving examination timetabling problems. We utilize the hierarchical hybridizations of four low level graph coloring heuristics, these being largest degree, saturation degree, largest colored degree and largest enrollment. These are hybridized to produce four ordered lists. For each list, the difficulty index of scheduling the first exam is calculated by considering its order in all lists to obtain a combined evaluation of its difficulty. The most difficult exam to be scheduled is scheduled first (i.e. the one with the minimum difficulty index). To improve the effectiveness of timeslot selection, a?roulette wheel selection mechanism is included in the algorithm to probabilistically select an appropriate timeslot for the chosen exam. We test our proposed approach on the most widely used un-capacitated Carter benchmarks and also on the recently introduced examination timetable dataset from the 2007 International Timetabling Competition. Compared against other methodologies, our results demonstrate that the graph coloring constructive hyper-heuristic produces good results and outperforms other approaches on some of the benchmark instances.     

青霉菌柚苷酶的分离纯化及酶学性质

对来源于Penicillium sp.1523的柚苷酶分离纯化工艺进行了系统分析,依次采用超滤、硫酸铵盐析和Sephadex G-200凝胶过滤层析操作对柚苷酶进行逐级纯化,通过SDS-PAGE电泳对各步骤的纯化结果进行分析鉴定,并考察了温度、pH及不同金属离子对酶活性的影响。结果显示纯化后的柚苷酶比活力达到4478.76U/mg,纯化倍数为11.99倍,活力回收率为38.10%。纯化后的柚苷酶经SDS-PAGE凝胶电泳鉴定显示两条清晰的条带,说明该酶由两个亚基组成,其分子量分别为89ku和72ku;同时酶学性质研究发现最适温度为50℃,热稳定性不理想,最适pH为4.0,Ca2+、Mg2+、Mn2+、Zn2+、EDTA、Cu2+对该酶酶活有促进作用,而Fe2+、SDS在低浓度时便对柚苷酶酶活表现出抑制作用。本研究为青霉菌柚苷酶的大规模生物转化及分子改性提供了实验基础。     

Research on cooling effectiveness in stepped slot film cooling vane

As one of the most important developments in air cooling technology for hot parts of the aero-engine,film cooling technology has been widely used.Film cooling hole structure exists mainly in areas that have high temperature,uneven cooling effectiveness issues when in actual use.The first stage turbine vanes of the aero-engine consume the largest portion of cooling air,thereby the research on reducing the amount of cooling air has the greatest potential.A new stepped slot film cooling vane with a high cooling effectiveness and a high cooling uniformity was researched initially.Through numerical methods,the affecting factors of the cooling effectiveness of a vane with the stepped slot film cooling structure were researched.This paper focuses on the cooling effectiveness and the pressure loss in different blowing ratio conditions,then the most reasonable and scientific structure parameter can be obtained by analyzing the results.The results show that 1.0 mm is the optimum slot width and 10.0 is the most reasonable blowing ratio.Under this condition,the vane achieved the best cooling result and the highest cooling effectiveness,and also retained a low pressure loss.     

以实施为导向的街区更新设计策略——以呼和浩特市乌兰察布街综合整治规划为例

街区的更新设计只有以实施为导向,形成具有实时性和长效性的技术文件,才能实现街区环境品质的真正改善和有效管理维护。呼和浩特市乌兰察布街综合整治规划探讨了面向实施的街区更新设计策略,包括分析城市街区问题及更新要素,构建适度而严谨的引导图则,建立多元行为主体的管理机制。