乙醛与氢氧化铜反应需强碱性条件的主因

针对教学中乙醛溶液与Cu（OH）2反应为什么需要强碱性溶液,可否直接采用硫酸铜溶液进行实验等困惑,通过计算比较乙醛在CuSO4溶液和强碱性Cu（OH）2悬浊液2种环境下可能发生的氧化还原反应的平衡常数,并结合乙醛被Cu（OH）2氧化的实证研究和动力学机理的解读,对该反应需控制强碱性的原因提出了新看法,认为碱性环境能显著提高乙醛的还原性、加快该反应的反应速率等才是主因,溶液中OH-或Cu（OH）42-浓度的大小是该反应的控制性因子。     

New alternating D–A1–D–A2 copolymer containing two electron‐deficient moieties based on benzothiadiazole and 9‐(2‐Octyldodecyl)‐8H‐pyrrolo[3,4‐b]bisthieno[2,3‐f:3',2'‐h]quinoxaline‐8,10(9H)‐dione for efficient polymer solar cells

A novel D–A₁–D–A₂ copolymer denoted as P1 containing two electron withdrawing units based on benzothiadiazole (BT) and 9‐(2‐octyldodecyl)?8H‐pyrrolo[3,4‐b] bisthieno[2,3‐f:3′,2′‐h]quinoxaline‐8,10(9H)–dione (PTQD) units was synthesized and characterized. The resulting copolymer exhibits a broad‐absorption spectrum, relatively deep lying HOMO energy level (?5.44 eV) and narrow optical bandgap (1.50 eV). Bulk heterojunction (BHJ) polymer solar cells (PSCs) based on P1 as donor and PC₇₁BM as acceptor with optimized donor to acceptor weight ratio of 1:2 and processed with DIO/CB solvent showed good photovoltaic performance with power conversion efficiency of 6.21% which is higher than that of the device processed without solvent additive (4.40%). The absorption and morphology investigations of the active layers indicated that structural and morphological changes were induced by the solvent additive. This higher power conversion efficiency could be mainly attributed to the absorption enhancement and improved charge transported in the active layer induced by the better nanoscale morphology of the active layer. This study demonstrated that a copolymer with two different acceptor moieties in the backbone may be promising candidate as donor copolymer for solution processed BHJ PSCs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 155–168     

Strong copper(II) species in estuarine and sea waters investigated by a method with high detection window

The distribution of copper(II) in species of different stability in some estuarine and sea water samples (Adriatic Sea) was investigated by a method based on the sorption of the metal ion on a strongly sorbing resin, Chelex 100, whose sorbing properties have been previously characterized. From them, it is possible to predict very high values of detection windows at the considered conditions, for example side reaction coefficient as high as 10¹⁰ at pH 7.5.Strong copper(II) species in equilibrium with Chelex 100 were detected, at concentration 2-20 nM, with a reaction coefficient approximately 10^10.6 at pH 7.45 in sea water, strictly depending on the acidity. They represent 50-70% of the total metal ion and are the strongest copper(II) complexes found in sea water. Weak complexes too were detected in all the samples, with reaction coefficient lower than ca. 10⁹ at the same pH.The method applied, named resin titration (RT), was described in a previous investigation, and is here modified in order to be carried out on oceanographic boat during a cruise in the Adriatic Sea.     

Synthesis, Crystal Structure and Luminescent Properties of TbCu（TeO3）2Cl

TbCu(TeO3)2Cl was obtained in high yield from high temperature solid-state reac-ion of Tb4O7,CuO,CuCl2 and TeO2 in a 1:2:2:8 molar ratio at 710 ℃ in an evacuated quartz tube. Its structure was established by single-crystal X-ray diffraction. The title compound crystal-lizes in monoclinic,space group P21/c,with a=5.409(2),b=14.994(6),c=9.183(4),β= 98.884(5)°,V=735.8(5) ?3 and Z=4. TbCu(TeO3)2Cl is isostructural with LnCu(TeO3)2X (Ln= Dy,X= Cl; Ln=Er,X=Cl,Br). Its structure features a three-dimensional (3D) network built from Tb(Ⅲ) and Cu(II) ions interconnected by tellurite and chloride anions; the chloride anion and the lone-pair electrons of the tellurium(IV) ions are oriented toward the cavities of the tunnels in the network. Solid-state luminescent spectrum of TbCu(TeO3)2Cl shows a strong emission band at 545 nm with a luminescent life time of 291 μs.     

积分中值定理的逆

从积分中值定理的几何意义出发 ,探讨出有关积分中值定理的逆 ,并进一步推出微分中值定理的逆     

非线性一致逼近中域上的局部强单一性常数

在局部Haar条件和其他一般条件下，把Bartelt和Henry的关于逼近域的线性一致逼近强单一性常数的连续性定理推广到非线性局部一致逼近．同时，Bartelt的关于逼近函数的强单一性常数的连续性定理也得到了推广．     

强余循环与辫子monoidal范畴

设 H为双代数 .σ∈ (H× H ) *是强余循环 ,本文证明在 m onoidal范畴μH中存在一个辫子 m onoidal子范畴μ( H ,σ) 。同时给出μ( H ,σ) =μH 的几个等价条件 ,从这些等价条件中得到 ,一个交换的双代数是辫子双代数     

关于高层建筑结构设计中的某些问题

结合工程设计中对钢筋砼高层建筑设计中一些问题进行探讨，提出在柱轴压比计算中应考虑钢筋的作用以及应按实际情况对高层建筑剪力墙暗柱面积合理取值，并指出结构抗震概念设计的重要性，从而掌握结构受力的规律和真实情况。     

从29届北京奥运会看中国男篮与世界强队间的差距

本文主要运用了文献资料法、数理统计法、录像观察法对29届北京奥运会上中国男篮与对手比赛技术统计数据进行对比分析,较深入地探讨了中国男篮与美国、西班牙、立陶宛等世界强队之间的差距,指出了中国男篮在进攻和防守等方面的不足,提出了相应的对策,以实现我国男篮队伍的和谐发展,促进我国男篮竞技水平的提高。     

二参数随机微分-积分方程解的存在性唯一性

在不假定边界过程矩存在的条件下,证明了一类相当一般的二参数随机微分——积分方程解的存在性唯一性,文中的结果减弱了随机微分方程解的存在唯一性定理的条件。