车前子中多糖含量的测定

采用蒽酮-硫酸法比色测定，用精制车前子多糖测得车前子多糖对葡萄糖的换算因子，对我国同属不同品种的车前子不同采集时间及炮制前后其多糖含量进行了比较研究。结果表明：此测定方法简便可行。供试液在8h内显色稳定，重现性较好，平均回收率为97．8％，RSD=1．41％(n=5)。江西吉安产大粒车前子生品多糖含量在9．15％～9．83％之间，炮制后其多糖含量在6．29％～6.81％之间；南昌新祺周车前GAP标准基地的大粒车前子生品多糖含量为7.85％～8．38％，炮制后其多糖含量为6．01％～6．64％；东北产的小粒车前子生品多糖含量为6．61％，炮制后其多糖含量为6．45％。     

Time Series Prediction Based on Chaotic Attractor

A new prediction technique is proposed for chaotic time series. The usefulness of the technique is thatit can kick off some false neighbor points which are not suitable for the local estimation of the dynamics systems. Atime-delayed embedding is used to reconstruct the underlying attractor, and the prediction model is based on the timeevolution of the topological neighboring in the phase space. We use a feedforward neural network to approximate thelocal dominant Lyapunov exponent, and choose the spatial neighbors by the Lyapunov exponent. The model is testedfor the Mackey-Glass equation and the convection amplitude of lorenz systems. The results indicate that this predictiontechnique can improve the prediction of chaotic time series.     

ON THE ACOUSTIC ABSORPTION OF MULTI-LAYER ABSORBERS WITH DIFFERENT INNER STRUCTURES

A rigorous finite element analysis procedure is developed to study the effect of the inner structures on the acoustic absorption of multi-layer absorbers. To do this, four types of basic inner structure compartments adopted in the multi-layer absorbers are selected for analysis. These compartments are composed of porous materials inlaid with perforated plates of various shapes, say, triangle, semicircle, convex rectangle and plate shapes. As it is different from the conventional finite element analysis for the acoustic system in the literature, the perforated plates are simulated by appropriate equivalent boundary conditions, depending on their thickness, hole radius, hole pitch and porosity and the air contained in the holes. A large number of total degrees of freedom generated from meshing the air in the holes of perforated plates are thus avoided. The results reveal that the inner structures of the multi-layer absorbers will influence the acoustic absorption at some frequency bands significantly. Based on those features, the multi-layer absorber with a novel inner structure is then designed and manufactured. Both the finite element and experimental results show that its acoustic absorption would be distinctly promoted.     

介孔网络电路

用二次阳极氧化法制备纳米多孔氧化铝板,然后用磁控溅射方式在纳米多孔氧化铝板表面镀金得到介孔网络电路,对该介孔网络电路进行输运测量,发现其具有非线性电阻.     

CFD在燃煤细粒子凝聚过程中的应用

燃煤产生的细粒子富集了大量的有毒痕量元素,对大气环境和人类健康造成严重危害。本文针对燃煤细粒子的形成过程,在计算流体力学(CFD)的基础上,结合气溶胶动力学理论,模拟了烟气中细粒子在圆柱形流场中由于碰撞而凝聚的过程,并通过计算结果分析细粒子颗粒特征参量(速度、质量、直径和颗粒数目)随流场的变化趋势,为深入研究燃煤细粒子的形成演化机理提供理论基础。     

声诱饵仿真试验系统

文章介绍了声诱饵仿真试验系统中的有关问题，包括：系统的组成、工作原理、对接装置结构等。建立了对接装置声耦合状态下的数学模型，对近场声压分布进行了仿真计算，得出了匹配材料厚度、发射和接收换能器的选取原则。     

乌桕类可可脂结晶过程中表现体积变化

为了解乌桕类可可脂(CTCBE)缓冷结晶横向胀罐爆裂原因，研究CTCBE结晶过程中的膨胀特性，采用流体静力法测试了不同等温结晶条件下CTCBE结晶形成的表观密度和表观体积及其横纵向膨胀状况。结果表明，CTCBE缓冷结晶后形成外部和中部两个晶区。在5-25℃的各等温结晶范围内，当结晶温度增加时，外部结晶区域减小、表观密度变化不大；中部结晶区域增大、表观密度明显减小，CTCBE的表观体积、横向、纵向膨胀率均增大，膨胀横向大于纵向。进一步表明CTCBE在自然缓冷固化的表观体积根本上由其结晶温度决定。为有效防止横向胀罐，自然缓冷固化温度应低于10℃。     

如何发现问题

在现代的各种教学思想中，都强调如何让学生在特定的教学资源中独立发现问题．因为发现问题是学习的起点，是对已有状态进行更深入的反思，没有问题的学习，从教的角度说叫“填”．从学的角度说叫“机械记忆”．发现问题的具体方法有如下几种．     

热致型胆甾酯液晶的相变研究

使用偏光显微镜观察胆甾烯壬酸酯液晶的相变，发现在不同的温度变化条件下液晶相变过程是不同的．本文讨论了其变化规律．     

GM(1,1)的周期修正模型及其在泉水流量预测中的应用

本文阐述了 GM( 1 ,1 )的残差周期修正模型 ,并将它应用于山西神头泉的流量预测中 ,建立了神头泉流量的 GM( 1 ,1 )周期修正模型 ,对其流量进行了预测 ,为神头泉域岩溶水资源开发利用和保护提供了科学依据