Synthesis, Structure and Characterization of Two 1D Chain-like Cadmium Terephthalate Complexes: [Cd(tp)(H2O)3]?·?4H2O and [Ph4P][Cd(tp)0.5Cl2]?·?H2O

Abstract  Two new compounds, [Cd(tp)(H₂O)₃] · 4H₂O (1) and [Ph₄P][Cd (tp)_0.5Cl₂] · H₂O (2) (tp = terephthalate, [Ph₄P] = tetraphenylphosphonium), are metal-polycarboxylate coordination polymers prepared by similar hydrothermal synthesis techniques. Both compounds crystallize in the 1D chain-like architectures. 1 (C₈H₁₈CdO₁₁) is orthorhombic Pcca, Z = 4 (a = 7.3018(1) ?, b = 9.9975(3) ?, c = 19.9695(5) ?, V = 1457.77(6) ?³). 2 (C₂₈H₂₄CdCl₂O₃P) is triclinic P−1, Z = 2 (a = 9.5028(4) ?, b = 12.3130(5) ?, c = 12.7343(6) ?, α = 68.380(1)°, β = 73.723(1)°, γ = 89.624(1)°, V = 1321.8(1) ?³). Transition metal cadmium centers bridged by rigid linear tp ligands give rise to a 1D infinite zigzag chain polymer for 1 and a simple 1D infinite stepped chain polymer for 2. 1 presents an interesting plywood-like packing network while 2 shows a simple parallel rod-like stacking network. An intense fluorescent emission at 412 nm (λ_exc = 338 nm) for 1 in the solid state at room temperature is observed. Index Abstract  Polymeric compounds [Cd(tp)(H₂O)₃] · 4H₂O (1) and [Ph₄P][Cd (tp)_0.5Cl₂] · H₂O (2) crystallize in two remarkable 1D chain-like architectures prepared by similar hydrothermal synthesis techniques, showing an interesting plywood-like packing network in 1 and a simple parallel rod-like stacking network in 2, respectively. An intense fluorescent emission at 412 nm (λ_exc = 338 nm) for 1 in the solid state at room temperature is observed.      

基于芳香酰腙配体的锰配合物的合成、晶体结构与性质

本文合成了2-羰基丙酸-2-甲氧基苯甲酰腙锰配合物,并借助X-射线单晶衍射测定了配合物的晶体结构。该晶体属于单斜晶系P-1空间群,晶胞参数为,a=0.7925(2)nm,b=1.0529(3)nm,c=1.1069(4)nm,α=68.142(6)°,β=69.053(4)°,γ=71.292(4)°,V=0.7816(4)nm~3,Z=1。在一个不对称单元中,Mn离子是七配位,且被镶嵌在一个有微弱形变的五角双锥结构内,配合物整体呈现双核的零维结构。利用红外光谱、紫外光谱、荧光光谱研究了其光谱性质。     

多复变Bergman空间上坐标乘子组的联合酉等价性

本文讨论多复变Ｂｅｒｇｍａｎ空间上坐标乘子组联合酉等价的条件以及与多复变Ｈａｒｄｙ空间上Ｔｏｅｐｌｉｔｚ算子组的关系     

The emergence of multiplicative thinking in children's solutions to paper folding tasks

Although children partition by repeatedly halving easily and spontaneously as early as the age of 4, multiplicative thinking is difficult and develops over a long period in school. Given the apparently multiplicative character of repeated halving and doubling, it is natural to ask what role they might play in the development of multiplicative thinking. We investigated this question by examining children's solutions to folding tasks, which involved predicting the number of equal parts created by a succession of given folds and determining a sequence of folds to create a given number of equal parts. Analyzing a combination of cross-sectional data and case studies from standardized clinical interviews, we found that children were most successful at coordinating folding sequences with multiplicative thinking when they used a conceptualization of doubling based upon recursion. This conceptualization tended to generate more sophisticated solutions.     

罗丹明B同步荧光猝灭法测微量磷的条件研究

本文研究了罗庆明Ｂ－磷钼杂多酸离子缔合物体系的荧光特性及测定方法，对实验条件进行了优化选择，并引入非离子表面活性剂ＯＰ对体系增敏，增稳。本法用于黑色食品中磷的测定，结果满意。     

Multiplication operators on spaces of integrable functions with respect to a vector measure

We study continuity and other properties related to some kind of compactness of multiplication operators between different spaces of pth power integrable scalar functions with respect to a vector measure.     

Why is paper-and-pencil multiplication difficult for many people?

In school, at least in the US, we were taught to multiply by hand according to a standard algorithm. Most people find that algorithm difficult to use, and many children fail to learn it. We propose a new way to make sense of this difficulty: to treat explicit computation as perceptually supported physical and mental action. Based on recent work in neuroscience, we trace the flow of arithmetic information to emphasize demands on visual working memory and attention. We predict that algorithms that make moderate demands on memory and attention will work better than others that make stronger demands. We suggest that the judicious use of spatial schemas can reduce such cognitive demands. Experimental evidence from children in an inner-city school supports this claim. Our work suggests new ways to think about instruction. The goal should be to minimize demands that present obstacles and maximize instead what human eyes, bodies, and brains do well.     

Rudin orthogonality problem on the Bergman space

In this paper, we study the Rudin orthogonality problem on the Bergman space, which is to characterize those functions bounded analytic on the unit disk whose powers form an orthogonal set in the Bergman space of the unit disk. We completely solve the problem if those functions are univalent in the unit disk or analytic in a neighborhood of the closed unit disk. As a consequence, it is shown that an analytic multiplication operator on the Bergman space is unitarily equivalent to a weighted unilateral shift of finite multiplicity n if and only if its symbol is a constant multiple of the n-th power of a Möbius transform, which was obtained via the Hardy space theory of the bidisk in Sun et al. (2008) [10].     

芳香亚胺与N-(4-甲基苯甲酰)-L-缬氨酸双阴离子合钯(Ⅱ)配合物的合成、晶体结构及体外抗肿瘤活性

本文首次报道了2个钯(Ⅱ)的配合物[Pd(bipy)(4-CH3Bzval-N,O)](1)和[Pd(phen)(4-CH3Bzval-N,O)](2)(bipy=2,2′-联吡啶,phen=1,10-菲咯啉,4-CH3Bzval-N,O=N-(4-甲基苯甲酰)-L-缬氨酸双阴离子)的合成及晶体结构,利用MTT法和SRB法研究了配合物的体外抗肿瘤活性。配合物2属单斜晶系P21/n空间群,其中a=1.162 92(8)nm,b=1.074 03(7)nm,c=1.821 14(12)nm,V=2.232 8(3)nm3,Z=4。结果显示:2个配合物对HL-60,BGC-823,Bel-7402和KB 4种人的肿瘤细胞表现出一定的活性和选择性,但其活性均小于顺铂。