大口径光束波前采样器(孔栅)的研制

应用平面波角谱理论，分析了采样器对光波场采样和分光的基本原理以及对空间采样频率的选择规则，描述了实际研制的大口径采样器的结构设计，并通过数值方法和高能激光大气传输实验研究了高能激光经采样器前／后的远场光斑分布关系。结果表明：利用光束波前采样器能高保真地实现对高能激光束的分光。     

CNx纳米管的制备、结构观察及低场致电子发射性能研究

采用高温热解法，以乙二胺为前驱液，在沉积有铁催化剂的p型硅（111）基底上制备出了定向生长的CNx纳米管.利用扫描电子显微镜、高分辨率透射电子显微镜和拉曼光谱对CNx纳米管进行了形貌观察和表征.CNx纳米管的高度在20?μm左右，直径在50—100nm之间，具有明显的“竹节状”结构，结晶有序度较差.对CNx纳米管薄膜进行低场致发射性能测试：外加电场为1.4V/μm，观察到20?μA /cm2发射电流，外电场升至2.54V/μm时发射电流达到1.280mA/cm2，在较高外电场下，没有发现电流“饱和”.这比 关键词： CNx纳米管 高温热解 “竹节状”结构 场致发射     

On topological properties of the Hartman-Mycielski functor

We investigate some topological properties of a normal functorH introduced earlier by Radul which is some functorial compactification of the Hartman-Mycielski construction HM. We prove that the pair (H X, HMY) is homeomorphic to the pair (Q, σ) for each nondegenerated metrizable compactumX and each denseσ-compact subsetY.     

Planar Chromatography of Some 1-Arylpiperazines Behaving as Dopaminergic Ligands

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of fourteen 1-arylpiperazine derivatives has been studied by thin-layer chromatography on both silica...     

Synthesis and characterization of polyaniline/graphite conducting nanocomposites

A new method for the synthesis of exfoliated graphite and polyaniline (PANI)/graphite nanocomposites was developed. Exfoliated graphite nanosheets were prepared through the microwave irradiation and sonication of synthesized expandable graphite. The nanocomposites were fabricated via the in situ polymerization of the monomer at the presence of graphite nanosheets. The as-synthesized graphite nanosheets and PANI/graphite nanocomposite materials were characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis (TGA). The conductivity of the PANI/graphite nanocomposites was dramatically increased over that of pure PANI. TGA indicated that the incorporation of graphite greatly improved the thermal stability of PANI. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1972–1978, 2004     

裂缝性地层黏弹性地震多波波动方程

裂缝检测是目前国内外石油勘探界研究的一个热点问题，如何确定裂缝方位等参数是石油公司面临的难题，而解决该难题就要确定裂缝方位等参数与地震波场传播之间的定量关系.但是目前所采用的裂缝性地层介质模型不能完全定量地反映裂缝的方位特征和衰减特征.针对该问题，建立了具有任意裂缝方位的裂缝性地层介质模型；并构造了时间增量的方法，将非线性的卷积积分采用近似的方法实现，建立了以位移场表示的具有任意方位角的黏弹性方位各向异性介质的波动方程.该波动方程定量地给出了黏弹性波场特征与裂缝走向的关系，描述了黏弹性地震波在这种介质中的 关键词： 裂缝 各向异性 黏弹性 波动方程     

掺杂偶氮苯聚合物光致异构Z扫描测量及其理论解释

用He_Ne激光对掺有偶氮苯聚合物DR 13的PMMA薄膜样品进行Z扫描研究 ,发现其折射率改变量与光强的关系存在着饱和效应 ,且线偏振光引起的折射率改变明显大于圆偏振光引起的折射率改变 .对于这些现象 ,用光致异构的角烧孔机理进行解释     

A Note on Topological Entropy of Maps

For a given collection of subsets of a compact metric space X which cover X,the entropies,hm(f)and hi(f),are introduced for a continuous map f of X to itseif. Also the concept of shadowing property with same end point (SPSEP for short) is introduced. The main results are,(1)H(f)≤hi(f)+hm(f)and,(2)h(f)=hm(f)whenever f has SPSEP,where h(f) is the topological entropy of f. Moreover,several corollaries are obtained.     

Melnikov向量与退化情形下的横截异宿轨道

利用指数二分性和泛函分析方法,我们研究了当未扰动系统不具有异宿流形的退化异宿分支.我们利用Melnikov型向量给出了系统在退化情形下的横截异宿轨道存在的充分条件.