Cobalt(II) coordination polymers built on isomeric dipyridyl triazole ligands with pyromellitic acid: Synthesis, characterization and their effects on the thermal decomposition of ammonium perchlorate

Three new cobalt(Ⅱ) coordination compounds,[Co(3,3’-Hbpt)2(H2pm)(H2O)2]·2H2O(1),[Co(4,4’-Hbpt)(pm)0.5(H2O)]·3H2O (2) and [Co(3,4’-Hbpt)(pm) 0.5 (H2O)3]·2H2O(3)(3,3’-Hbpt=3,5-bis(3-pyridyl)-1H-1,2,4-triazole;4,4’-bpt=3,5-bis(4-pyridyl)1H-1,2,4-triazole,3,4’-Hbpt=3-(3-pyridyl)-5-(4’-pyridyl)-1H-1,2,4-triazole and H4pm=pyromellitic acid) have been synthesized by hydrothermal reactions.Single-crystal X-ray diffraction reveals that compound 1 has a one-dimensional (1D) chain network,2 exhibits a four-connected three-dimensional (3D) structure with 1D open channels encapsulated by water molecules,while 3 displays a regular two-dimensional (2D) architecture connected through 1D metal helical chains.In addition,the efficacy of compounds 1-3 as additives to promote the thermal decomposition of ammonium perchlorate (AP) is explored by differential scanning calorimetry (DSC).     

2(n1+n2)-(k1+k2)42混合水平裂区设计包含纯净效应的条件

混水平部分因析裂区设计在各类试验中有广泛应用. 在三因子及更高阶交互作用可以忽略这一很弱的假设下, 试验者可以得到纯净主效应或者纯净两因子交互作用成分的无偏估计. 本文给出了含有两个四水平因子和若干二水平因子的混水平裂区设计包含各类纯净主效应或者纯净两因子交互作用成分的条件以及构造相应设计的方法.     

Families of hyperelliptic curves with maximal slopes

For each integer g≥2, we construct a family of hyperelliptic curves of genus g whose slope reaches the upper bound obtained by Xiao.     

Coupling-matrix approach to the Chern number calculation in disordered systems

The Chern number is often used to distinguish different topological phases of matter in two-dimensional electron systems. A fast and efficient coupling-matrix method is designed to calculate the Chern number in finite crystalline and disordered systems. To show its effectiveness, we apply the approach to the Haldane model and the lattice Hofstadter model, and obtain the correct quantized Chern numbers. The disorder-induced topological phase transition is well reproduced, when the disorder strength is increased beyond the critical value. We expect the method to be widely applicable to the study of topological quantum numbers.     

Influence of donor–acceptor conjugation between thiophene‐phthalazinone structures containing Sp3 CN bond on the frontier orbital levels and optic–electronic properties

Herein, an electron‐deficient phthalazinone unit containing a unique Sp³ hybrid nitrogen atom as an acceptor to cut off the ether bond was presented and three Donor–Acceptor (D–A) conjugated fluoropolymers via Classical Aromatic Nucleophilic Displacement Polymerization (CANDP) method were successfully synthesized. These polymers exhibit excellent thermostability. The 5% weight loss temperature of PDT2TF under nitrogen atmosphere is high, up to 470 °C. This is due to that the D–A conjugation between thiophene‐phthalazinone units affects its resonance energy and stabilizes the thiophene‐phthalazinone structures. These three fluoropolymers show strong absorptions and fluorescence in visible light region both in solution and thin film states. The band gaps (E_g) of these polymers are narrower than that of their corresponding di‐NH capped monomers, owing to the good electronic communication properties of the Sp³ nitrogen atom in the phthalazinone unit. The E_g value of PDT3TF is decreased to 2.03 eV. These results indicate that phthalazinone unit is an efficient acceptor and could exhibit strong D–A effect with thiophene unit. Also, the Sp³ nitrogen atom in the phthalazinone shows good electronic wave function and charge transport properties. This facile CANDP synthetic method combined with Sp³ C? N bond linked electron‐deficient phthalazinone unit affords polymers with controllable photoelectric properties. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3470–3483     

Synthesis, photophysical properties and TD-DFT calculation of four two-photon absorbing triphenylamine derivatives

In this study,linear absorption,single-photon excited fluorescence,fluorescence quantum yields,fluorescence lifetime and two-photon excited fluorescence of a series of triphenylamine derivatives (L1,L2,L3 and L4) have been measured.L1 and L3 are D--A type dyes,while L2 and L4 are D--D--A type dyes (D=donor,A=acceptor).The investigated compounds consist of triphenylamine-bearing donor-substituted and/or systematically extended-conjugated length,which are designed to gain insight into the effect of the ethoxyl unit and-linkage length on the linear and nonlinear optical properties.The influence of solvent polarity on the photophysical properties was investigated.Employing time-dependent density functional theory (TD-DFT) calculations,the structure-property relationships are discussed.     

气体水合物膜生长动力学研究进展

由于大多数水合物客体不溶于水,水相与客体相界面首先形成一层气体水合物膜,气体水合物膜生长是水合物生长的主要形式,研究水合物膜生长规律对于理解水合物生长动力学及进一步开发促进和抑制水合物生长的应用技术具有重要意义.本文综述了近年来气体水合物膜生长形态、横向生长和增厚生长的理论和实验研究进展.首先介绍了不同客体-水体系(包括气/液界面、液/液界面和气-液-液体系)形成的水合物膜生长形态随实验条件的变化规律,然后分别从横向生长和增厚生长两方面总结了水合物膜生长的实验和模型方面的研究工作,阐述了常见的膜生长速率和膜厚度的测量方法,分析了水合物膜生长的传热和传质机理.同时展望了未来水合物膜生长研究的发展方向.     

燃料电池中氢电极催化剂的研究

燃料电池是借助于电池内的燃烧反应，将化学能直接转为电能的装置，是一种新型的高效化学电源，是除火力、水力、核能之外的第四种发电方式。对燃料电池，性能良好的催化剂至关重要，它决定着大电流密度放电时的电池性能、运行寿命和成本。燃料电池的催化剂应该满足以下条...     

Quantum statistical entropy corresponding to cosmic horizon in five-dimensional spacetime

The generalized uncertainty relation is introduced to calculate the quantum statistical entropy corresponding to cosmic horizon. By using the new equation of state density motivated by the generalized uncertainty relation, we discuss entropies of Bose field and Fermi field on the background of five-dimensional spacetime. In our calculation, we need not introduce cutoff. There is no divergent logarithmic term in the original brick-wall method. And it is obtained that the quantum statistical entropy corresponding to cosmic horizon is proportional to the area of the horizon. Further it is shown that the entropy corresponding to cosmic horizon is the entropy of quantum state on the surface of horizon. The black hole’s entropy is the intrinsic property of the black hole. The entropy is a quantum effect. In our calculation, by using the quantum statistical method, we obtain the partition function of Bose field and Fermi field on the background of five-dimensional spacetime. We provide a way to study the quantum statistical entropy corresponding to cosmic horizon in the higher-dimensional spacetime. Supported by the National Natural Science Foundation of China (Grant No. 10374075) and the Natural Science Foundation of Shanxi Province, China (Grant No. 2006011012)     

5-硝基间苯二甲酸钬配合物的合成、结构及标准摩尔生成焓

以5-硝基间苯二甲酸与硝酸钬在水溶液中反应制备了配合物Ho2(5-nip)2-(5-Hnip)2(H2O)8·4H2O(5-H2nip为5-硝基间苯二甲酸),并对其进行了元素分析、红外、热重和X-射线单晶衍射表征.结构分析表明,配合物中5-Hnip?以?2-?1:?1双齿桥连模式将两个相邻Ho3+离子连接成二聚体形式,分子间的O–H···O氢键和三种不同的?-?堆积作用使相邻的二聚体单元与游离水分子形成三维超分子结构.运用RD496-2000型微热量计在298.15 K下测定了该化合物在水溶液中生成反应的焓变.设计合理的热化学循环,辅助文献的热化学数据,以Hess定律计算得到了该化合物在298.15 K下的标准摩尔生成焓θf m?H为?(3371.5±16.9)kJ/mol.