Laser-induced convenient fabrication of CdS nanocages with super-adsorption capability for methyl blue solution

We report on the successful synthesis of cadmium sulfide(CdS) nanocages by laser ablation of bulk Cd target in thioacetamide(TAA) solution. The CdS nanocages exhibit obvious interior hollow spaces and distinctive porous-shell structures. After laser ablation of Cd target in liquid condition, the unique structure should be attributed to the initial formation of Cd micro-gas bubble via a model of micro-explosive boiling model. Surprisingly, the obtained CdS nanocages can provide a super-adsorption of methyl blue(MB) solution. The maximum adsorption capacity reaches up to 11813.3 mg/g,which is much higher than that reported in many previous researches. Without using any complicated stabilizers or soft directing agents, the pure CdS nanocages fabricated by laser ablation will serve as advanced absorbents in further research.     

纳米氢氧化镁的合成及其形貌控制

用乙醇和水的混合溶剂热法合成氢氧化镁纳米材料,并用透射电镜(TEM)和X射线衍射(XRD)表征其形貌和结构,同时考察了镁源、温度、反应时间、反应物浓度和溶剂热体系对氢氧化镁纳米材料形貌的影响,探索其生长机理。镁源通过改变氢氧化镁纳米粒子的结晶习性从而影响形貌,温度和反应时间受热力学和动力学的控制使氢氧化镁纳米材料的生长从六个等价面的取向生长向各向同性生长转变,从而导致形貌由六边形片状结构向圆形变化,反应物浓度和溶剂热体系影响成核快慢,从而影响氢氧化镁纳米材料的晶型。     

Syntheses,Crystal Structures and DNA-binding Properties of Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) Complexes Containing Imidazolium Derivatives

Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) complexes(1~4) based on 2-(2-pyridyl)benzimidazole(pbm) and 4,4'-oxybisbenzoic acid(H2odc) were synthesized. The formulas of these complexes are [Cd(pbm)(odc)2](1), [Co(pbm)(odc)2](2), [Cu(pbm)(odc)2](3) and [Zn(pbm)(odc)2](4) confirmed by single-crystal X-ray diffraction analysis, which shows that complexes 1, 2 and 4 belong to monoclinic system with space group P21/n, while complex 3 belongs to monoclinic system with space group P21/c. The binding properties of complexes 1~4 with CT-DNA are evaluated by ultraviolet spectrum, fluorescence spectra and viscosity measurements. The results indicate that complexes 1~4 have strong interaction with CT-DNA binding. These complexes exhibit an electrostatic or groove mode in respect of binding with DNA, which can effectively destroy DNA. And this binding mode may be applied to the interaction between the complexes and cancer cell DNA. Therefore, we hope to provide a theoretical and scientific basis for the research of anti-cancer drugs.     

具有弹性对称面复合材料的Ⅲ型剪切缺陷或裂纹群应力强度因子的计算

本文应用lsida提出的复势罗朗展开法分析了具有弹性对称面复合材料的Ⅲ型剪切缺陷、裂纹群问题。在缺陷或裂纹平行分布情况下以级数形式给出了应力强度因子的计算公式。文中指出,对一般各向异性材料中的平行裂纹群问题,或正交各向异性复合材料中的平行缺陷或裂纹群问题,其解可简单地通过比拟由各向同性问题的解获得。     

Laser-induced fabrication of highly branched CuS nanocrystals with excellent near-infrared absorption properties

We report on the successful fabrication of highly branched Cu S nanocrystals by laser-induced photochemical reaction.Surprisingly, the single-crystalline nature with preferential alignment of the(107) orientation can be well improved during the moderate growth process. The branch length drastically increases from about 5 nm to 6 μm with an increase of photochemical reaction time(0-40 min). The absorption spectra of as-prepared Cu S nanodendrites show that localized surface plasmon resonance(LSPR) peaks can be modulated from about 1037 nm to 1700 nm with an increase of branch length. Our results have a promising potential for photodynamic therapy and biological imaging application.     

有限空心圆柱体的三维非轴对称变形分析

本文应用Pickett双重级数展开法的思想研究了有限空心圆柱体的非轴对称三维变形问题。文中先将位移势函数展为Fourier级数和Fourier-Bessel级数之和,在一定边界条件下,两级数中的系数可以互相表示,这样,我们可获得一组联立代数方程组。求解此方程组,最后可求得问题的解。文中给出了一个计算实例,表明这样构造的解是收敛的。