Self-assembly of Polyaniline: Mechanism Study

在水热环境下合成出\掺杂电荷诱导自组装纳米纤维阵列结构的聚苯胺平板,并通过一系列设计实验研究了这种自组装微观结构的形成机理,例如在反应溶液中引入不参与反应、对电荷组装起干扰作用的电解质,以及用计算模拟体系静电能与纳米纤维阵列夹角的相互关系等实验．实验结果发现,由掺杂离子引起的静电相互作用在形成聚苯胺自组装结构的过程中起了重要的作用．     

轴向隐失波激励的回音壁模式光纤激光器

采用轴向隐失波激励增益的方式,使激光增益区域局限在光纤回音壁模式的模场区域内,显著地降低了回音壁模式光纤激光辐射的抽运阈值,由此形成一种低阈值的回音壁模式光纤激光器.在微焦耳量级的低抽运能量条件下,用回音壁模式光纤激光器研究了激光染料的浓度效应.实验结果表明,随着激光染料浓度的增加,回音壁模式激光辐射的波长向长波方向移动,激光波长范围变宽.用回音壁模式染料激光的四能级模型得到激光上能级和所有能级上的分子数比值γ(λ)曲线后,很好地解释了实验结果.低抽运阈值的回音壁模式光纤激光器,为研究液体激光现象提供了极为便利的手段.     

Singularities and spectral changes of Gaussian beams focused by a lens with spherical aberration

We address the effect of the truncation parameter and spherical aberration (SA) on the singularity transformation and spectral behavior of the polychromatic Gaussian beams focused by an aperture lens with SA in detail. The numerical simulation results, based on the derived equations of the intensity and the spectral density, are given. It is found that the axial singularities vanished with the change of the truncated parameter. The intensity and drastic spectral change fade away with an annihilation process of the phase singularities, and the drastic spectral change does not disappear immediately at the moment the phase singularity annihilates. The singularities in the focal region will redistribute with the increment of SA coefficient, some singularities will vanish, some will spilt into two new singularities, and other off-axial singularities will appear and split into two new singularities as well. When SA coefficient changed, we can find that the axial singularities disappear as well with the decreasing value of truncation parameter. These new splitted singularities due to the change of SA coefficient will converge into one singularity again and disappear gradually.     

Mott relation for anomalous Hall and Nernst effects in Ga1-xMnxAs ferromagnetic semiconductors

The Mott relation between the electrical and thermoelectric transport coefficients normally holds for phenomena involving scattering. However, the anomalous Hall effect (AHE) in ferromagnets may arise from intrinsic spin-orbit interaction. In this work, we have simultaneously measured AHE and the anomalous Nernst effect (ANE) in Ga1-xMnxAs ferromagnetic semiconductor films, and observed an exceptionally large ANE at zero magnetic field. We further show that AHE and ANE share a common origin and demonstrate the validity of the Mott relation for the anomalous transport phenomena.     

Tuning the band gap of self-assembled superparamagnetic photonic crystals in colloidal magnetic fluids using external magnetic fields

The model of tunable superparamagnetic photonic crystals self-assembled in colloidal magnetic fluids under externally applied magnetic fields is established. The mechanisms, which are in charge of the tunability of the band gaps with magnetic fields are clarified. The band structures of the triangularly-arrayed two-dimensional photonic crystals with limited heights of magnetic columns are calculated with the experimental data of structures and refractive indices in the literatures. The field-dependent properties of the first band gaps are gained for the z-odd and z-even modes, respectively. Simulation results indicate that the mid frequencies of the first band gaps of the z-odd modes can be easily tuned by the external magnetic fields, while those of the z-even modes bear relatively weak dependence on the external magnetic fields. Simultaneously, the first band gaps of both kinds of modes become wide along with the increase of the magnetic fields. The results presented in this work give a guideline for realizing the tunable photonic crystals with magnetically colloidal materials and magnetic stimuli.     

Complex quantum gases: spinor Bose–Einstein condensates of trapped atomic vapors

We discuss the energy eigenstates, ground and spin mixing dynamics of a spin-1 spinor Bose–Einstein condensate for a dilute atomic vapor confined in an optical trap. Our results go beyond the mean field picture and are developed within a fully quantized framework.     

纺织复合材料能量吸收性能的研究进展

纺织复合材料的能量吸收性能是近年来一个十分引人注目的研究课题．本文综述了近年来对纺织复合材料能量吸收性能研究的最新进展,包括纤维纺织结构、纺织复合材料的制造及加工、材料的能量吸收机理及失效模式、能量吸收性能的测试方法等．     

1‐Dodecene Hydroformylation Catalyzed by Water Soluble Rhodium Phosphine Complex in Two‐Phase System

1‐Dodecene hydroformylation catalyzed by water soluble rhodium complex [RhCl(CO) (TPPTS)₂] was studied in the presence of TTPTS [P(m‐C₂H₄SO₃Na)₃] and CTAB (cetyltrimethyl ammonium). The influence of reaction parameters was discussed in detail based on micelle effect in biphasic system. The modification for the microcircumstance of micelle interface was conducted by the introduction of a catalyst promoter TPPDS [PhP(m‐C₂H₄SO₃Na)₂] into the reaction solution. A synergistic effect between TPPDS and TPPTS on the regioselectivity of 1‐dodecene hydroformylation was observed. The selectivity of linear aldehyde in the products was so high as 95.7% at the molar ratio of [TPPDS]/[TPPTS] = 0.5.     

Crystal Structure and Characterization of Pd(II) Bis(diiso‐propyldithiocarbamate) Complex

The crystal and molecular structure of [Pd(iPr₂dtc)₂] (dtc = dithiocarbamate) have been determined by X‐ray crystallography. The unit cell of the crystal structure consists of two discrete monomelic molecules of [Pd(iPr₂dtc)₂]. The Pd(II) ion has an square‐planar geometry. The electronic and IR spectral data are in agreement with the X‐ray structure. The TG data indicate slight degradation of a few percent.     

聚-γ-N(β-丁硫基)乙基胺丙基硅氧烷钯的合成及其在硅氢加成反应中的催化活性

报道了聚 -γ -N(β-丁硫基 )乙基胺丙基硅氧烷钯多齿配位络合物的合成及其在硅氢加成反应中的催化活性 ,该络合物在 110℃下硅氢加成中对 1-十二烯、癸烯、烯丙基苯基醚、苯丙烯表现出良好的催化活性 .使用 2 3 .2mg络合物 (含 4.9× 10 -6molPt)为催化剂、分别使用 1.9× 10 -3 mol1-十二烯、癸烯、烯丙基苯基醚、苯丙烯进行硅氢加成反应 ,在 0 .75h内产率超过 75 % .该催化剂存在半年以上活性无明显改变 ,催化活性随反应温度的升高而升高 ,该催化剂具有良好的回收再利用性能