Effect of actuating frequency on plasma assisted detonation initiation

Aiming at studying the influence of actuating frequency on plasma assisted detonation initiation by alternating current dielectric barrier discharge, a loosely coupled method is used to simulate the detonation initiation process of a hydrogenoxygen mixture in a detonation tube at different actuating frequencies. Both the discharge products and the detonation forming process which is assisted by the plasma are analyzed. It is found that the patterns of the temporal and spatial distributions of discharge products in one cycle are not changed by the actuating frequency. However, the concentration of every species decreases as the actuating frequency rises, and atom O is the most sensitive to this variation, which is related to the decrease of discharge power. With respect to the reaction flow of the detonation tube, the deflagration-todetonation transition(DDT) time and distance both increase as the actuating frequency rises, but the degree of effect on DDT development during flow field evolution is erratic. Generally, the actuating frequency affects none of the amplitude value of the pressure, temperature, species concentration of the flow field, and the combustion degree within the reaction zone.     

深挖隐含条件 速寻解题入口——以“圆锥曲线”问题为例

合理利用已知条件是问题顺利求解的关键,但某些命题中条件的给出并不是直接的,而是需要解题者深入挖掘才能得到的.那么,如何才能正确挖掘出这些隐含的条件,决定着问题能否顺利解决.本文笔者以圆锥曲线问题为例,就其隐含条件的探究提几点建议,供广大读者参考.一、挖掘解析几何的平面几何性     

关于圆周率的一些常识

对于圆周率π，从小学阶段开始，我们就经常碰到它．对于这样一个十分熟悉的符号，你对它了解多少呢？本文简单谈一谈关于丌的一点常识．     

均匀球体转动惯量的多种求法

用不同的方法计算了均匀球体的转动惯量,以开拓学生的思路,提高学生的学习兴趣.     

生物表面活性剂修复重金属污染土壤的研究进展

重金属污染土壤的治理与修复是当前社会关注和国内外研究的热点.在众多重金属污染治理方法中,基于表面活性剂的化学淋洗技术由于具有原位、高效、治理成本低、可同时去除多种重金属和非水溶性有机污染物等特性成为研究的重点.相对于化学表面活性剂,生物表面活性剂因其优良的耐极端温度、耐盐碱、可生物降解、不产生二次污染的绿色安全特性成为目前国内外研究的热点.经过近年的发展,生物表面活性剂在重金属污染土壤修复方面的应用已取得诸多成果,本文从去除土壤重金属的机理方面总结了国内外生物表面活性剂研究的发展历程和最新进展,并对应用生物表面活性剂修复重金属污染土壤的未来发展进行了展望.     

Common Features in Electronic Structure of the Oxypnictide Superconductors from Photoemission Spectroscopy

High resolution photoemission measurements are carried out on non-superconducting LaFeAsO parent com- pound and various superconducting RFeAs（O1-ZFx） （R=La, Ce and Pr） compounds. It is found that the parent LaFeAsO compound shows a metallic character. By extensive measurements, several common features are identified in the electronic structure of these Fe-based compounds： （1） 0.2 eV feature in the valence band, （2） a universal 13-16 meV feature, （3） near EF spectral weight suppression with decreasing temperature. These uni- versal features can provide important information about band structure, superconducting gap and pseudogap in these Fe-based materials.     

酞菁配合物对锂-亚硫酰氯电池正极的催化作用

合成过渡金属酞菁配合物MPc(M=Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ),N i(Ⅱ),Cu(Ⅱ)),研究MPc及其中心离子对L i/SOC l2电池正极的催化作用,并提出相关催化机理.     

功能高分子型活性材料结构对钆离子选择电极性能的影响

本文采用接枝共聚方法合成功能高分子型钆化合物活性材料,研究了它们的结构和某些性能,结果表明这些活性材料的结构和性能对钆离子选择电极性能有较大的影响。