爱尔朗排队系统的瞬态分析

对于一般分布的排队系统的瞬态解是一个相当复杂的问题，本文利用把福克－普朗克方程降阶去奇异性，转人继有外力作用的状态方程，利用Ｒｕｎｇｅ－Ｋｕｔｔａ法，求得系统的瞬态及稳态解，并给出不同参数时的曲线族。     

蕨状满江红(Azolla filiculoides)孢子果和幼孢子体的SEM系统观察

通过对Azolla filiculoides孢子果和幼孢子体的SEM系统观察,进一步了解其个体发育过程中的形态特点,这有助于对A.filiculoides的鉴别和了解其适应于有性生殖的形态特点,气孔是由一个细胞所组成,与前人所推测不同.     

Regularities of formation and lattice distortion of perovskite-type compounds

Based on 489 known perovskite-type complex oxides and a number of other type complex oxides, the pattern recognition-atomic parameter method is adopted to find regularities of the formation and the lattice distortion of the perovskite structure. It has been found that the restriction on Goldschmidt's t factor constitutes only a necessary but not a sufficient condition to form perovskite-type compounds. A more effective mathematical model, which can precisely sum up the regularities of the formation, the lattice distortion,and the cell constants of known perovskite-type compounds and reliably make corresponding predictions on unknown compounds, can be set up by integrating multiple atomic parameters such as ionic radii, ionic valency, and Basanov's electronegativity of constituent elements. Based on it, an intelligent database has been implemented. Its prediction accuracy is tested by eight newly discovered perovskite-type compounds such as Eu(Mn0.5 Ni0.5)O3, etc. (they are not included in the database during the test). The prediction resuits are in agreement with experimental facts.     

柱前衍生反相高效液相色谱法同时测定植物络合素(PCn)等巯基化合物

介绍一种荧光试剂monobromobimane柱前衍生，反相高效液相色谱一荧光检测测定标准样品和植物组织中植物络合素(PCn)等巯基化合物的方法．结果表明，采用乙腈和0．1％三氟乙酸组成的二元梯度洗脱程序，标准混合液中PCn等5种巯基化合物15min内得到很好的分离．以谷胱甘肽为代表考察方法的精密度，在1．25～160ng/μL浓度范围内与峰高有较好的线性关系，相关系数r^2=0．9999．谷胱甘肽的回收率平均为97．64％，40d内的变异系数平均为2．21％．方法具有快速、灵敏、稳定性好、易于实施、同时测定PCn等多种巯基化合物等优点．通过该方法的应用，首次揭示Cd超积累植物东南景天对CA的超量积累和解毒与PCn无关．     

Mlgebraic Attack on Filter-Combiner Model Keystream Generators

Algebraic attack was applied to attack Filter-Combiner model keystream generators. We proposed thetechnique of function composition to improve the model, and the improved model can resist the algebraic attack. A new criterion for designing Filter-Combiner model was also proposed: the total length L of Linear Finite State Machines used in the model should be large enough and the degree d of Filter-Combiner function should be approximate [L/2].     

Field Emission Characterization of 1D-Nanostructural ZnO Grown at Low Temperature

Ondeu-ctdio rmse nhsaivoen aaltt rwaicdteed b aan gdr-egaatp d neaaln oosft uartctteunrtialon se bmeiccaounse-of their remarkable physical and chemical properties[1 ,2].Amongthose properties ,the highaspect ratio of these materi-als makes them genuine can…     

稳定土厂拌站监控系统的设计与实现

针对稳定土厂拌站采用的电子计量微机控制的方式,研究了基于“组态王”工控组态软件的监控系统的设计和实现,分析了稳定土厂拌站配料系统的特点,进而确定了系统的硬件架构;接着介绍了用“组态王”设计监控软件各主要功能模块的基本思想及涉及到的几个技术难点;最后研究了系统实现稳定配比控制的算法,该算法主要采用增量式控制和输出限幅的思想.现场测试实验证明,本系统真实再现了稳定土厂拌站的生产工艺流程,实现了配方/生产报表管理、故障报警等功能,并能对配料过程进行实时控制,保证产品达到一定的配比要求.     

天然气与焦炉煤气比较

文章分别介绍了天然气和焦炉煤气作为城市民用燃气的特点 ,并就太原市即将开始的天然气转换工作从压力级制选择、输配管网改造、计量器具更换等方面进行了探讨。     

基于ASP技术的Web数据库安全机制分析

WWW的迅速发展,使得Web技术与数据库枝术紧密结合,因此研究基于Web的数据库安全机制对于信息系统的安全保护有着很重要的实际意义。分析了目前常见的几种Web数据库的连接技术,详细阐述了利用ASP相关技术实现基于Web数据库安全机制的一种方法。