Synthesis of triphenylamine-cored dendritic two-photon absorbing chromophores

[structure: see text]. A new series of dendritic two-photon absorbing chromophores containing triphenylamine moiety as a core or branching points have been synthesized through a convergent synthetic strategy. One-photon and two-photon optical properties of these molecules were characterized. In the nanosecond time domain, these molecules exhibited large two-photon absorption (TPA) cross sections up to 7.56-12.2 x 10(-44) s cm(4) at 800 nm, indicating that these molecular structures were viable candidates for various two-photon related applications.     

反应条件对Mo2C/Al2O3催化的POM制合成气的影响

考察了反应温度、气体空速和进料中CH4：O2比值对Mo2C／Al2O3催化的POM反应制合成气的影响．结果发现较高的温度具有较高的甲烷转化率、CO和H2的选择性；而在较低的温度下，对CO的选择性比对H2的影响更大．反应气体的空速较小时对于甲烷的转化率、CO和H2的选择性是有利的；而在较高的气体空速下，氢气的选择性则更低．进料中CH4：O2比值稍高于2：1时有利于获得高的甲烷转化率、CO和H2的选择性．并且还可以增加催化剂的稳定性．当CH4：O2比值低于2：1时．甲烷转化率、CO和H2选择性随反应的进行急剧下降．而当此比值调整到高于2：1时．转化率和选择件都可以得到恢复。     

氯化钠对锂离子电池石墨负极的修饰改性

Numerous carbonaceous materials have been studied as anodes of lithium ion batteries during the past several years[1￣4].Graphite was favored for battery applications because it exhibits a high specific capac- ity, low working potential close to that of l…     

Theoretical Study on the Reaction Mechanism of Ketene CH2CO with Isocyanate NCO Radical

The bimolecular single collision reaction potential energy surface of an isocyanate NCO radical with a ketene CH2CO molecule was investigated by means of B3LYP and QCISD（T） methods. The computed results indicate that two possible reaction channels exist on the surface. One is an addition-elimination reaction process, in which the CH2CO molecule is attacked by the nitrogen atom at its methylene carbon atom to lead to the formation of the intermediate OCNCH2CO followed by a C-C rupture channel to the products CH2NCO＋CO. The other is a direct hydrogen abstraction channel from CHzCO by the NCO radical to afford the products HCCO＋HNCO. Because of a higher barrier in the hydrogen abstraction reaction than in the addition-elimination reaction, the direct hydrogen abstraction pathway can only be considered as a secondary reaction channel in the reaction kinetics of NCO＋ CH2CO. The predicted results are in good agreement with previous experimental and theoretical investigations.     

Dienone—phenol Rearrangement of C—9 Oxygenated Decalinic Dienone and Analogs through B—Ring Cleavage

Dehydrogenation of 9-hydroxy decalinic enones and analogs with DDQ resulted in a formal dienone-phenol type rearrangement via B-ring cleavage, while the corresponding dienone acetates underwent base-catalyzed formal dienone-phenol type rearrangement analogously.     

The first silver-catalyzed three-component coupling of aldehyde, alkyne, and amine

[reaction: see text] Silver iodide catalyzed the three-component coupling of aldehyde, alkyne, and amines to generate propargylic amines with high efficiency in water. The silver-catalyzed reaction is especially effective for reactions involving aliphatic aldehyde. No additional cocatalyst or activator is required.     

Lattice locations determination of trace amount carbon in gallium arsenide by theoretical calculation of CPAA with channeling

Combining the Charged Particle Activation Analysis (CPAA) and the Channeling Technique, the partial concentrations of the impurity carbon atoms in different crystal lattice locations of GaAs were claculated. The calculated results show that at lower total concentrations (0.3 ppm), carbon atoms occupy principally the octahedral and displaced octahedral interstitial positions, but at higher total concentrations (2 ppm), the substitutional carbon plays a principal role.     

Waugh-型镍钼杂多酸的量子化学计算

采用半经验INDO法，完成了Waugh-型镍钼杂多酸（NH44）6〔NIMO9O32〕·6H2O的量子化学计算，得到146个成键轨道和78个反键轨道，轨道能级，电荷和键序等数据。通过对这些数据的分析，表明杂多酸分子中端氧和Ni都可能为化学活性中心，各原子轨道在分子轨道中都占有一定比例，其HOMO和LUMO能级皆为负值，其体系具有进一步接受电子的能力。这些结论与实验事实一致。     

乙烯砜型染料与丙烯腈的水相沉淀聚合

he copolymerization of vinyl sulphone dyes with acrylonitrile were carried outin HIO media. The effects of the increase in dye concentration on the conversionof copolymerization molecular weight of copolymer, and the content of dyechromophores combined in the copolymer were studied. The eghaneemellt on thetermination of macromolecular radicals by added dyes was discussed.     

Biosorption of copper(II) and zinc(II) from aqueous solution by Pseudomonas putida CZ1

To study Pseudomonas putida CZ1, having high tolerance to copper and zinc on the removal of toxic metals from aqueous solutions, the biosorption of Cu(II) and Zn(II) by living and nonliving P. putida CZ1 were studied as functions of reaction time, initial pH of the solution and metal concentration. It was found that the optimum pH for Zn(II) removal by living and nonliving cells was 5.0, while it was 5.0 and 4.5, respectively, for Cu(II) removal. At the optimal conditions, metal ion biosorption was increased as the initial metal concentration increased. The adsorption data with respect to both metals provide an excellent fit to the Langmuir isotherm. The binding capacity of living cells is significantly higher than that of nonliving cells at tested conditions. It demonstrated that about 40-50% of the metals were actively taken up by P. putida CZ1, with the remainder being passively bound to the bacterium. Moreover, desorption efficiency of Cu(II) and Zn(II) by living cells was 72.5 and 45.6% under 0.1M HCl and it was 95.3 and 83.8% by nonliving cells, respectively. It may be due to Cu(II) and Zn(II) uptake by the living cells enhanced by intracellular accumulation.