Synthesis and Characterization of Vanadium Substituted Dawson-Type Heteropoly Acid （Mo, As）

SubstitutedDawson typepolyoxometalateshave beencalledinorganicmetalloprophyrinbecauseof analogousstructureofmetalloprophyrinandstronger antioxidantthanmetalloprophyrin.Theywerealso usedaseffectivenovelcatalystsofalkeneepoxyring reactions[1].Becausevanadiu…     

新型轻质碳基泡沫材料研制

采用中间相沥青和原煤为碳源和发泡材料,硅粉为硅源,通过发泡、炭化和石墨化分别制备了高导热沥青基炭泡沫体、煤基炭泡沫体和碳化硅泡沫.采用扫描电子显微镜(SEM)和X射线衍射(XRD)分析了样品的微观结构,测定了样品的部分力学和热学性能.分析结果表明所制备样品性能达到了国外商业化产品的水平.     

基于FEPG有限元分析系统的树脂充模过程模拟

为优化复杂预成型体结构的液体成型工艺,基于有限元法/生死节点法模拟了复合材料液体模塑成型过程树脂流动,并针对典型矩形平板、圆板结构、I型加筋壁板充模过程进行了仿真与验证。结果表明:典型矩形平板和圆板结构的充模过程模拟结果与理论解一致性较好,验证了生死节点法跟踪树脂流动前锋的有效性。含有方腔的变厚度圆柱体和正方体三维实体结构的充模过程模拟验证了有限元方法对三维结构的适用性。基于有限元法/生死节点法的液体充模过程模拟方法对于复杂求解区域具有更好适应性,可用于复杂实体结构的液体模塑成型工艺过程树脂流动规律预测、指导模具设计及工艺优化。      

Synthesis and Properties of a One-Dimensional Mixed-Ligand Cd(Ⅱ) Complex with Helical Structure

The title complex,[[Cd(Him)(OH-BDC)(H2O)2]·3H2O]n(1) (Him is imidazole,OH-H2BDC is 5-hydroxyisophthalic acid),was synthesized by liquid/liquid diffusion method at room temperature.The complex crystallizes in orthorhombie,space group P212121,with a = 0.671 6(7),b = 1.380 6(2),c =1.7421(2) nm,V = 1.615 2 (3) nm3,C11 H18 CdN2O10,Mr = 450.67,Dc = 1.853 g/cm3,μ =1.407 mm-1,F(000) = 904,Z = 4,the final R1 = 0.020 9 and wR 2 = 0.045 3 for 3 211 observed reflections (Ⅰ＞ 2σ (Ⅰ)).In the structure of 1,the OH-BDC ligands exhibiting bis-bidentate coordimtion mode bridge the adjacent Cd centers to form a one-dimensional helical chain and the second ligand Him acting as terminal ligands are attached to the helical chain.It is notable that a series of complicated hydrogen bonds (e.g.,N-H ...O,O-H...O) exist in the structure,which link neighboring helices into a three-dimensional supramolecular architecture.An observed intense blue luminescence with an emission band peaking at 390 nm for 1 may be resulted from ligand-to-metal charge transfer (LMCT).     

细编穿刺织物的数学建模理论与实例

针对细编穿刺织物,采用具有参数连续性的样条线作为纤维丝束的轨迹特性函数,建立了三维立体织物结构的数学抽象与三维建模方法。基于MicroCT方法实际测量的细编穿刺织物结构特征参数,采用四种丝束轨迹特性函数和两种丝束截面建立了八种穿刺织物结构的三维数字模型,通过丝束结构与孔隙率的对比,三维数字模型与织物真实结构符合较好。该织物结构数学抽象与三维建模方法,可用于小尺度的亚单胞模型与大尺度的宏观模型分析,具有较高的适应性。