红枣及红景天色素的提取及稳定性的比较研究

对红景天及红枣色素的提取方法和色素的基本性质进行了研究比较。结果表明,红景天色素以95%(pH=3)的乙醇水溶液提取时效果最佳,色素的最大吸收峰在314nm处;红枣色素以50%(pH=3)的乙醇水溶液提取时效果最好,色素的最大吸收峰在320nm处;日光、温度和大多数金属离子Ca2 、Mg2 、Mn2 、Zn2 等对这2种色素的稳定性都无太大的影响,但是Na 、Fe2 、K 对红景天色素有增色的趋势,Fe2 对红枣色素有增色的趋势。这2种色素的耐糖性和耐光性都很好。红景天色素在酸性条件下pH稳定性好,但在碱性环境下pH稳定性较差,而红枣色素的pH稳定性在无论在酸性或在碱性条件下都稳定。     

两种石耳中多糖的提取与分离纯化及其单糖组成分析

目的:对网脊石耳(Umbilicaria decussate(Vill.)Zahlbr.)和淡肤根石耳(Umbilicaria virginis Schaer.)多糖中的单糖组成进行研究。方法:两种石耳经水提、醇沉、冷冻干燥得水溶性多糖,经DEAE-52离子交换层析柱和SephadexG-150凝胶柱进行分离纯化得纯化多糖。气相色谱分析所得多糖的单糖组成。结果:淡肤根石耳精制多糖的单糖组为甘露糖、葡萄糖、半乳糖,其含量之比为16.00:50.96:6.17、淡肤根石耳纯化多糖的单糖组成为甘露糖、葡萄糖、半乳糖,其含量之比为2.97:17.70:1.52;网脊石耳精制多糖的单糖组成为甘露糖、葡萄糖、半乳糖,其含量之比为3.90:38.086:2.00、网脊石耳纯化多糖只含葡萄糖,含量为5.37%。结论:网脊石耳和淡肤根石耳都含有葡萄糖,含有少量的甘露糖和半乳糖。     

Using Forward Reachability Analysis for Verification of Lossy Channel Systems

We consider symbolic on-the-fly verification methods for systems of finite-state machines that communicate by exchanging messages via unbounded and lossy FIFO queues. We propose a novel representation formalism, called simple regular expressions (SREs), for representing sets of states of protocols with lossy FIFO channels. We show that the class of languages representable by SREs is exactly the class of downward closed languages that arise in the analysis of such protocols. We give methods for computing (i) inclusion between SREs, (ii) an SRE representing the set of states reachable by executing a single transition in a system, and (iii) an SRE representing the set of states reachable by an arbitrary number of executions of a control loop. All these operations are rather simple and can be carried out in polynomial time.With these techniques, one can straightforwardly construct an algorithm which explores the set of reachable states of a protocol, in order to check various safety properties. We also show how one can perform model-checking of LTL properties, using a standard automata-theoretic construction. It should be noted that all these methods are by necessity incomplete, even for the class of protocols with lossy channels.To illustrate the applicability of our methods, we have developed a tool prototype and used the tool for automatic verification of (a parameterized version of) the Bounded Retransmission Protocol.     

Systematic linearisation of a microfluidic gradient network with unequal solution inlet viscosities demonstrated using glycerol

This paper presents a mathematical and experimental study of the effect of inlet concentration (and therefore viscosity) of glycerol solutions on the performance of a microfluidic network. This was achieved with analytical modelling, implemented in MATLAB, and optical measurement of the entire concentration distribution of the network. A mathematical proposal to improve the linearity of the outlet profile is also implemented and successfully verified experimentally. The concentration gradients of a two inlet–six outlet (2–6) microfluidic network device were obtained with inlet solutions of 10–40 wt% glycerol and flow rates of up to 5 μl/s per inlet. The mathematical model developed gave a good agreement with the experimental results obtained. ‘S’ shaped outlet profiles were obtained for the four glycerol cases studied and the closest results to the model were achieved at an optimised flow rate of 1μl/s for 10 wt% glycerol, 5 μl/s for both 20 and 30 wt% glycerol and 1.5 μl/s for 40 wt% glycerol. The linearity of the outlet profiles for the 20, 30 and 40 wt% inlet glycerol experiments were improved from R ² of 0.977, 0.946 and 0.966, respectively (before linearisation) to their new values of 0.997, 0.995 and 0.974, respectively (after the linearisation). This was performed by application of the mathematical model, at controlled inlet flow rate ratios of 0.77, 0.63 and 0.52 with respect to the viscous inlet, for 20, 30 and 40 wt% glycerol experiments, again with very good agreement of the outlet performance between the experimental and the mathematical results.     

Exploration of the multiparameter space of nanosecond-laser damage growth in fused silica optics

Historically, the rate at which laser-induced damage sites grow on the exit surface of SiO2 optics under subsequent illumination with nanosecond-laser pulses of any wavelength was believed to depend solely on laser fluence. We demonstrate here that much of the scatter in previous growth observations was due to additional parameters that were not previously known to affect growth rate, namely the temporal pulse shape and the size of a site. Furthermore, the remaining variability observed in the rate at which sites grow is well described in terms of Weibull statistics. The effects of site size and laser fluence may both be expressed orthogonally in terms of Weibull coefficients. In addition, we employ a clustering algorithm to explore the multiparameter growth space and expose average growth trends. Conversely, this analysis approach also identifies sites likely to exhibit growth rates outside the norm. The ability to identify which sites are likely to grow abnormally fast in advance of the manifestation of such behavior will significantly enhance the accuracy of predictive models over those based on average growth behaviors.     

Synthese multifunktioneller polycylischer chiraler Furanoide durch Pyranoseanellierungen

Synthesis of Chiral Multifunctional Polycyclic Furanoids via Annulation of Pyranosides A new strategy to chiral polyfunctionalized furanoids from 2 , 3 , 4 , 7 , 8 , 9 , 11 , 12 , 14 , 15 , 17 and 18 from cis-orientated epoxypyranosetriflates 1 and 6 and dianions of β-dicarbonyl compounds 10 , 13 and 16 is described. The control of the substituents in the satellite ring through acid catalysis is discussed.     

亚花松萝多糖的提取与分离工艺的优化

本文研究亚花松萝多糖的提取与分离工艺的优化。亚花松萝多糖提取工艺各因素的最佳水平为热水体积200ml（每4g松萝）、70～80℃提取三次，每次2h。其中对亚花松萝多糖含量影响最显著的因素是提取次数，然而提取温度在一定范围内无显著影响。乙醇沉淀多糖的最佳浓度为80％一倍，Sevage试剂除游离蛋白时的体积比为3：1，反复脱蛋白五次，每次振荡30min。多糖的最佳得率为6．86％，总糖含量为76％。     

A classification of the expressive power of well-structured transition systems

We compare the expressive power of a class of well-structured transition systems that includes relational automata (extensions of), Petri nets, lossy channel systems, constrained multiset rewriting systems, and data nets. For each one of these models we study the class of languages generated by labeled transition systems describing their semantics. We consider here two types of accepting conditions: coverability and reachability of a fixed a priori configuration. In both cases we obtain a strict hierarchy in which constrained multiset rewriting systems is the most expressive model.     

小檗饮料的研制

介绍了小檗饮料的生产工艺过程。通过正交试验,对影响饮料品质的几个因素进行了研究和讨论,确定了最佳配方,得到了风味、色泽均佳的一种新型饮料。