具有偶型位势的二阶系统周期解的存在性定理

用极小作用原理得到了具有偶型位势的非自治二阶系统周期解的一存在性定理。     

半无限长柱体出水数值模拟

自由面流动在工程问题中经常遇到。为研究半无限长柱体出水过程中 ,不同的 We和 Fr对自由面的影响 ,基于VOF(volume of fluid)的基本思想 ,使用改进的 Youngs算法实现体积分数的近似和推进 ,对问题进行了数值研究 ,分别得到了该问题的 We和 Fr临界值 :当 We大于临界值时 ,可以忽略表面张力的作用 ;当 Fr大于临界值时 ,可以忽略重力的影响     

Dieterici实际气体热力学性质的计算与分析

本对Dieterici实际气体的热力学性质做了比较细致的分析，首先计算Dieterici实际气体的两个主要热力学函数，内能和熵，导出了Cp-Cv和[зU/зV]T的数学表示式，再依据对应态原理得到了Dieterici实际气体的临界压缩因数Zc，综个所述和vdW物态方程，RK物态方程所得结果一起与气体的实验测量值进行了比较和分析，说明了Dieterici物态方程不仅比vdW物态方程更贴近实际气体的行为和热力学性质，而且对于碳氢化合物类物质来说甚至超过了目前在生产实践中应用较多的RK物态方程。     

亚临界锅炉减温水量过大问题的技术改造

某亚临界锅炉在电厂运行中出现了严重的减温水量过大的问题 ,本文借鉴前人的经验 ,通过研究提出技术改造方案 ,并将各方案进行分析和比较 ,同时考察其工程实际应用效果 ,对同类问题具有很大的参考价值     

一个半线性椭圆型方程非平凡解的存在性

摘要：研究一个半线性椭圆型偏微分方程，在失去某种紧性条件的情况下，运用没有(PS)条件的山路引理，汪明了此方程的非平凡解的存在性．     

弗莱雷的"被压迫者教育学"

《被压迫者教育学》堪称巴西教育家弗莱雷长达六年的真实体验和实践的结晶,在许多发展中国家甚至发达国家都产生了深远的影响。他所提出的解放教育就是要使被压迫者形成批判性意识。因此,进步主义教育家应从解决教师与这生这对矛盾入手,采用提问式教育、对话行动理论等方式帮助学生实现意识化。     

一类星染色的临界图

研究了图的星染色的临界图的性质，得到了x^*临界图的一些必要条件和充分条件，并给出一类星染色的临界图，它在星染色中的作用如同正常染色中的完全图。     

Effect of Nano－SiC and Nano－Si Doping on Critical Current Density of MgB2

The discovery of superconductivity in magnesium diboride (MgB2) has opened up a new field in materials science research. It offers a possibility of a new class of high performance superconducting materials for practical applications because of the relatively low cost of fabrication, high critical current densities (Jc)and fields, large coherence length, absence of Weak links, higher Tc (Tc = 39 K) compared with Nb3Sn and Nb-Ti alloys (two or four times that of Nb3Sn and Nb-Ti alloys). However, the weak flux pinning in the magnetic field remains a major challenge. This paper reports the most interesting results on nenomaterial (SiC and Si) doping in magnesium diboride. The high density of nano-scele defects introduced by doping is responsible for the enhanced pinning. The fabrication method, critical current density, microstructures, flux pinning and cost for magnesium diboride bulks, wires and tapes are also discussed. It is believed that high performance SiC doped MgB2 will have a great potential for many practical applications at 5K to 25K up to 5T.     

Self-aggregation of vapor-liquid phase transition

The concept of the molecular free path is introduced to derive a criterion distinguishing active molecules from inactive molecules in liquid phase. Based on molecular self-aggregation theory a concept of the critical aggregation concentration (CAC) of active molecules is proposed to describe the physical configuration before the formation of the nuclei in the process of vapor-liquid phase transition. All active molecules exist in the form of the monomer when the concentration of active molecules is lower than CAC, while the active molecules will generate aggregation once the concentration of the active molecules reaches CAC. However, these aggregates with the aggregation number N smaller than 5 can steadily exist in bulk phase. The other excess active molecules can only produce infinite aggregation and form a critical nucleus of vapor-liquid phase transition. Without outer perturbation the state point of CAC corresponds to the critical superheated or supercooled state in the process of vapor-liquid phase transition. With the aggregate property, the interfacial tension between the bulk phase and the tiny new phase is predicted and a correction is made for the classical nucleation rate in a quite good agreement with experimental results.     

二维简谐势阱中理想气体玻色-爱因斯坦凝聚的转变温度

用直接数值求和的方法研究了低温、低密度理想量子气体的玻色一爱因斯坦凝聚问题．对于二维简谐势阱体系，计算了体系粒子数给定时玻色一爱因斯坦凝聚的转变温度，并分析了积分方法与数值求和方法存在差别的原因．结果表明在低温、低密度条件下采用数值方法可更精确的反映系统的特性，积分方法的结果应作修正．