英语翻译Specific Microsolvation Triggers Dissociation-Mediated A

英语翻译
Specific Microsolvation Triggers Dissociation-Mediated Anomalous Red-Shifted Fluorescence in the Gas Phase
Abstract
Ion-depletion IR spectroscopy has revealed that at least two water molecules are required in complexes with 4-(dimethylamino)benzoic acid methyl ester (DMABME) for anomalous red-shifted fluorescence to occur in the gas phase.Through the use of high-level quantum-chemical calculations,two experimentally observed isoenergetic isomers are assigned to complexes in which a water dimer is hydrogen-bonded either to the carbonyl oxygen of the ester function or to the amino nitrogen.Surprisingly,computed IR spectra reveal that the N-bonded isomer is responsible for the observed red-shifted fluorescence.For an explanation,the mechanism of twisted intramolecular charge-transfer (TICT) formation and energy dissipation is investigated in detail.In general,for red-shifted fluorescence to occur,the N-bonded complexes must be able to dissipate energy,which in the gas phase can only happen nonradiatively via fragmentation.Arguments are given that only the N-bonded isomer photodissociates rapidly enough into free DMABME and a water dimer as a result of the immediate repulsion between the amino nitrogen and the water dimer in the TICT state.The O-bonded isomer,on the other hand,stays intact because the hydrogen bond is strengthened by additional electrostatic attraction in the ICT state.Furthermore,an experiment to further corroborate that mechanism is suggested.
Article
Investigation of the Internal Heterostructure of Highly Luminescent Quantum Dot−Quantum Well Nanocrystals
Abstract
In this paper,we report on the growth and characterization of quantum dot−quantum well nanostructures with photoluminescence (PL) that is tunable over the visible range.The material exhibits a PL efficiency as high as 60% and is prepared by reacting ZnS nanocrystals in turn with precursors for CdSe and ZnS in an attempt to form a simple “ZnS/CdSe/ZnS quantum-well structure”.Through the use of synchrotron radiation-based photoelectron spectroscopy in conjunction with detailed overall compositional analysis and correlation with the size of the final composite nanostructure,the internal structure of the composite nanocrystals is shown to consist of a graded alloy core whose composition gradually changes from ZnS at the very center to CdSe at the onset of a CdSe layer.The outer shell is ZnS with a sharp interface,probably reflecting the relative thermodynamic stabilities of the parent binary phases.These contrasting aspects of the internal structure are discussed in terms of the various reactivities and are shown to be crucial for understanding the optical properties of such complex heterostructured nanomaterials.
1楼，如果在用线翻译的话，我也会。

Specific Microsolvation Triggers Dissociation-Mediated Anomalous Red-Shifted Fluorescence in the Gas Phase
特殊的微溶剂化作用触发气相中的解离介导异常红移荧光
Abstract
Ion-depletion IR spectroscopy has revealed that at least two water molecules are required in complexes with 4-(dimethylamino)benzoic acid methyl ester (DMABME) for anomalous red-shifted fluorescence to occur in the gas phase.离子耗损红外光谱法业已揭示,对异常红移荧光在气相中的发生来说,在与4－（二甲烷基）苯甲酸甲酯（DMABME）的络合物中至少需要两个水分子.Through the use of high-level quantum-chemical calculations,two experimentally observed isoenergetic isomers are assigned to complexes in which a water dimer is hydrogen-bonded either to the carbonyl oxygen of the ester function or to the amino nitrogen.通过采用高水平的量子化学计算,从实验上观察到的两个等能异构体被分配于那些络合物,在这些络合物中,双水分子与酯官能的羰基氧或与氨基氮氢结合.Surprisingly,computed IR spectra reveal that the N-bonded isomer is responsible for the observed red-shifted fluorescence.令人惊异的是,计算的红外光谱揭示,N结合的异构体主导了观察到的红移荧光.For an explanation,the mechanism of twisted intramolecular charge-transfer (TICT) formation and energy dissipation is investigated in detail.作为一种解释,对分子内扭转电荷转移（TICT）的形成和能量耗散的机理详细进行了研究.In general,for red-shifted fluorescence to occur,the N-bonded complexes must be able to dissipate energy,which in the gas phase can only happen nonradiatively via fragmentation.总的来说,对于红移荧光的发生来说,N结合的络合物必须能耗散能量,这在气相中只能通过裂解非辐射地发生.Arguments are given that only the N-bonded isomer photodissociates rapidly enough into free DMABME and a water dimer as a result of the immediate repulsion between the amino nitrogen and the water dimer in the TICT state.提供的论据是只有N结合异构体足够快地光游离（分裂）成自由的DMABME和双水分子,其原因是氨基氮与双水分子之间在TICT状态下直接排斥的结果.The O-bonded isomer,on the other hand,stays intact because the hydrogen bond is strengthened by additional electrostatic attraction in the ICT state.Furthermore,an experiment to further corroborate that mechanism is suggested.另一方面,O结合的异构体则停留着原封不动,因为氢键由于在TICT状态下额外的静电吸引而增强了.而且,使人想起了一项进一步证实该机理的实验.
Article
Investigation of the Internal Heterostructure of Highly Luminescent Quantum Dot−Quantum Well Nanocrystals
高发光量子点－量子阱纳米晶的内部异质结研究
Abstract
摘要
In this paper,we report on the growth and characterization of quantum dot−quantum well nanostructures with photoluminescence (PL) that is tunable over the visible range.在本文中,我们报道了具有在可见光范围内可调的光激发荧光（PL）的量子点－量子阱纳米结构.The material exhibits a PL efficiency as high as 60% and is prepared by reacting ZnS nanocrystals in turn with precursors for CdSe and ZnS in an attempt to form a simple “ZnS/CdSe/ZnS quantum-well structure”.这种材料呈现出高达60％的PL效率,并且通过ZnS纳米晶依次与CdSe和ZnS用的前驱体反应来制备,从而形成一种简单的“ZnS/CdSe/ZnS 量子阱结构”Through the use of synchrotron radiation-based photoelectron spectroscopy in conjunction with detailed overall compositional analysis and correlation with the size of the final composite nanostructure,the internal structure of the composite nanocrystals is shown to consist of a graded alloy core whose composition gradually changes from ZnS at the very center to CdSe at the onset of a CdSe layer.通过采用基于同步辐射的光电子光谱方法,结合详细的整体组分分析和与最终复合物纳米结构尺寸的相互关系,该复合物纳米晶的内部结构证明是由渐变的合金芯构成的,其组分在很中心为ZnS,逐渐变化为CdSe层开始处的CdSe.The outer shell is ZnS with a sharp interface,probably reflecting the relative thermodynamic stabilities of the parent binary phases.外壳是带有陡削界面的ZnS,或许反映了原始二元相的相对热动力稳定性.These contrasting aspects of the internal structure are discussed in terms of the various reactivities and are shown to be crucial for understanding the optical properties of such complex heterostructured nanomaterials.内部结构的这些产生反差的方面用各种不同的反应性进行了讨论,并证明对于了解这些络合物异质结的纳米材料来说是非常关键的.