磷酸硅锌铝分子筛（ZnAPSO—5）的合成,结构及性能研究

以二乙氨基乙醇为导向剂,用水热晶化法合成了磷酸硅锌铝分子筛纯相,测定其组成为Zn_(1.12)Si_0.38Al_(10.88)P_(11.62)O_(48),并对其结构和性能进行了研究.实验结果表明,ZnAPSO-5具有AlPO_4-5型分子筛结构,由于锌和硅进入骨架同晶取代了部分铝和磷,致使ZnAPSO-5分子筛有了B酸酸性,而热稳定性也较磷酸锌铝分子筛(ZAPO-5)有所提高.     

RE-ESTABLISHMENT OF SYMBIOSIS TO Anabaena-FREE Azolla

Symbiosis to Anabaena-free Azolla has been re-established by placing indusium containing Anabaena onto the Anabaena-free megasporocarps. Anabaena-free megasporocarps were obtained by removing the indusium and the apical membrane of the megaspore apparatus of normal Azolla. The recovery of symbiosis in artificially reconstituted Azolla-Anabaena association was confirmed using the scanning electron microscope, monoclonal antibody test (McAb-C_(16)), and nitrogen fixation capacity (ARA).Laboratory-grown Anabaena azollae cells inoculated subsequently to the decapitated megaspore apparatus were observed to have entered the leaf cavities of sporophyte, although some portions of Anabaena filaments were found outside the leaf cavity. Plants invaded by artificially inoculated Anabaena did not have sufficient N_2-fixing activity to allow the growth in the N-free medium.     

Self-Dual Chern-Simons Vortices in Higgs Field

By decomposing the Bogomol＇nyi self-dual equation in the Abelian Chern-Simons Higgs model, we find a selldual topological term that was ignored all the time in the Bogomol＇nyi self-duality equation due to the improper decomposition of the complex Higgs field. We also present a new self-dual equation that includes the topological term. It is shown that the self-dual vortex just arises from the symmetric phase of the Higgs field φ =0. Using our p-mapping theory, the inner topological structure of the vortex and double vortex is given.     

Enhancement of Critical Current Density and Flux Pinning in Acetone and La2O3 Codoped MgB2 Tapes

MgB2 tape samples with simultaneous additions of acetone and La2O3 were prepared by an in？situ processed powder-in-tube method. Compared to the pure and single doped tapes, both transport Jc and fluxing pinning are greatly improved by acetone and La2O3 codoping. Acetone supplies carbon into the MgB2 crystal lattice and increases the upper critical field, while the La2O3 reacts with B to form LaB6 nanoparticles as effective flux pining centers. The improvement of the superconducting properties in codoped tapes can be attributed to the combined effects of improvement in Hc2 and flux pinning.     

Analysis of Second-Harmonic Generation from CuttbPc LB Film／Metal Interface

Second-harmonic generation signals from a CuttbPc LB film deposited on metal (Al or Au)-glass substrates were investigated. It was observed that there were two second-harmonic peaks at the wavelength of 1060 and 1250nm in the CuttbPc/Al film, but only one peak at 1050nm in the CuttbPc/Au film. Meanwhile the surface electric potentials (SEP) at the interfaces of LB film/metals were also measured using a Kelvin probe. The SEP in the CuttbPc/Al decreases and eventually approaches a saturated value of -1.0V as the film thickness increases, while the SEP in the CuttbPc/Au is nearly zero. Based on the experimental results and theoretical analysis, it was considered that the space-charge-induced electric field makes a main contribution to the second-harmonic generation at 1250nm in the CuttbPc/Al film.     

高温高压下非晶Co80B20合金的相稳定性

本文研究常压至770kbar压力范围内,非晶Co₈₀B₂₀合金所形成的结晶相的结构,并与Fc-B非晶合金进行比较。 关键词：     

点接触方式纳米锌润滑添加剂自修复规律的研究

本文采用四球试验法,以含纳米锌自修复剂的基础油为润滑介质,运用均匀设计试验方法对磨损的钢球进行在线自修复试验,建立并验证回归模型,对影响自修复效果的因素量化排序.选择不同修复效果的试验条件,分别加入抗氧抗腐剂T202和空白试验研究点接触方式下自修复过程特点.用带能谱仪的扫描电镜对修复后钢球磨斑表面进行表征.结果表明:试验验证结果与预测值符合较好,说明回归模型可行、可信.纳米锌自修复剂能对磨损的钢球表面进行修复,向表层基体元素扩散并牢固结合,使磨斑直径减小,具有自修复特点.     

对合的分解

利用流形的双连通和概念可以定义两个n维流形上的对合(T_1,M_1)和(T_2,M_2)的双连通和,记作(T_1,M_1)§(T_2,M_2),它是定义在M_1与M_2的双连通和M_1§M_2上的一个对合T_1§T_2。一个对合称为可约化的,若它可以表为两个连通流形上的对合之双连通和。     

血清中硫脂质的提纯及其结构分析

应用离子交换及硅胶柱色谱法分离提纯血清中酸性脂质,并采用薄层色谱法(TLC)、TLC免疫染色法、质谱法及溶化分解等方法分析血清中硫脂质的种类及结构。实验确定了样品的提纯体系,证实胆固醇硫酸及脑硫脂是血清中的主要硫脂质。     

Second harmonic generation at the interface of copper tetra-tert-butyl phthalocyanine Langmuir-Blodgett film/metal

As one of the most primitive nonlinear optical phenomena, optical second harmonic genera-tion (SHG) has been investigated for half a century and it has become a very useful spectroscopic tool in the study of surface and interface[1—3]. It was theoretically shown that the SH signal cannot be generated in a centrosymmetric system. However, the generation of SH signal from the centro-symmetric molecules such as fullerene (C60) and CuPc has been detected[4—7]. In our recent ex-periments, an …