分子激发态寿命及其应用研究

寿命测量现在使用的有位相偏移法和脉冲法。本工作是利用脉冲法进行的。本论文做了三方面的工作：1.分子激发态寿命在分析化学中的应用。荧光寿命是荧光物质的特征参数，可利用来进行定性，定量分析工作。从荧光强度与荧光寿命的基本公式I＝A_ie~(-t/τi)出发，可以得到c_1/c_2=(a_1τ_1ε_2φ_2)/(α_2τ_2ε_1φ_1)其中C_1，C_2是同一体系中两种不同物质的浓度，τ是荧光寿命，ε为激发波长下的消光系数，φ为量子产率，A是幅度常数。ε与φ可预先测量或查表得到。τ，A可根据荧光衰减曲线与标准衰减函数相拟合，解卷积后同时得到。因此可用上式进行定量分析。本论文利用上式分析了卟吩类化合物，其中包括四苯基卟吩；四－邻氯苯基卟吩；锌－四苯基卟吩络合物在不同浓度下的组合，分析误差绝大多数在10％以内。从（1）式出发得到另一个基本公式A＝KCT其中T为时间相关单光子计数时间，K是一常数。根据（3）式进行了多环芳香碳氢化合物分析。稀土发光材料的荧光寿命研究。本工作者首先使用不同的激发光源，不同分光装置和不同的讯号探没器及讯号处理方式，建立了测量范围较宽的荧光寿命测量装置。测量了Eu~(3+), Eu~(2+), Ce~(3+), Dy~(3+), Nd~(3+), Tb~(3+)在不同基质中的荧光寿命。其数值从10~(-8)秒到10~(-3)秒，探测波长包括可见和近红外，并进行了要必的讨论。直接测定单线态氧在溶液中寿命的研究。本工作装置了一套近红外弱信号探测系统测定了O_2(~1△_g)在液相中的磷光寿命。

微型机在X射线荧光谱法分析稀土试样数据处理上的应用

用Basic 语言、按I=I_i-I_(bi)-∑A_(ij)I_j 计算模式自编数据处理程序。程序适用于元素含量0.1～99%混合稀土氧化物。所得结果与萃取色谱法、ICP 法一致。本程序特点是:1)增加或删去某些程序段,不影响本程序完整性;2)一次输入所有分析样品中全部元素的测量强度,计算结果由打印机全部打印出来;3)每个样品所需时间不超过两分钟。X 射线荧光谱法分析稀土试样时,由于稀土元素谱线间相互重迭现象较严重,给测试数据处理带来许多困难。本文将测试数据按自编计算程序输入微型机,按照计算公式,采用迭代法,归一化处理,自动计算并打印(或显示)出分析结果。几年来,处理了数万个测试数据,报出的数万个结果完全能满足流程及扩试生产对数据的要求。

A couple of embroiled sheets of Miguel Barnades Manaider and Esteban de Prado in the Herbaria of Real Colegio Alfonso XII of San Lorenzo de El Escorial (Madrid)

In this paper we present a couple of sheets of Umbelliferae that are preserved in the RCAXII herbaria. One of them, Selinum carvifolia, where collected in the Gredos Mountains by Miguel Barnades Mainader and was identified by his son Miguel Barnades Clarís. The other, Tragium flabellifolium, was collected in Mieres (Asturias) by Esteban de Prado and identified by Mariano La Gasca.

Europa : paisagem e pensamento : um excurso sobre Teixeira de Pascoaes, Friedrich Hölderlin, José Marinho e Martin Heidegger

Tese de doutoramento, Filosofia (Filosofia em Portugal), Universidade de Lisboa, Faculdade de Letras, 2014

L'empereur Charles d'Autriche, [son épouse Zita] et ses enfants [Félix, Robert, Otto et Adélaïde, reproduction d'une photographie] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 58305

Activitat 5. J.-H. Fragonard

Material didàctic del grup d'investigació Observatori sobre la Didàctica de les Arts (ODAS)

Honoris causa

El 18 de novembre de 2008 la Universitat de Girona va investir Eric J. Hobsbawm i Miquel Roca doctors honoris causa en un acte solemne que va aplegar gairebé tres-centes persones. La rectora, Anna M. Geli, va definir aquesta manifestació acadèmica com el “compromís d’acceptar, de manera crítica i constructiva, la transmissió de saber i de coneixement del llegat dels doctors Hobsbawm i Roca Junyent”. Així mateix, va manifestar que ambdós doctors “són part del segle XX” perquè “l’han viscut i l’han explicat” i han contribuït a fer “un món més habitable i a mostrar-nosen les deficiències”

Serveis Tècnics de Recerca. Unitat d'Assessorament Estadístic

La Unitat d’Assessorament Estadístic es va crear el passat mes de març i es va incorporar als Serveis Tècnics de Recerca. La seva creació respon a la necessitat cada vegada més gran que hi ha a la Universitat de Girona d’una gestió i interpretació eficaç dels resultats que proporcionen les bases de dades. També era una necessitat per a institucions i empreses del territori, perquè a Girona no hi havia cap servei d’aquestes característiques

Didàctica del moviment en educació musical

L’estudi que s’ha dut a terme vol descriure com s’integra i desenvolupa el treball del moviment i la dansa a les sessions d’educació musical de 19 escoles d’educació infantil i primària a partir de les observacions i intervencions d’estudiants de tercer curs en pràctiques dels estudis de Mestre/a en Educació Musical de la Universitat de Girona. D’una altra banda, l’estudi pretén també contribuir a que l’estudiantat desenvolupi una capacitat d’observació de l’activitat docent més estructurada, reflexiva i crítica i a que millori la relació i integració dels coneixements teoricopràctics i professionals

Basis set superposition error-counterpoise corrected potential energy surfaces : application to hydrogen peroxide ... X (X=F-, Cl-, Br-, Li+, Na+) complexes

Møller-Plesset (MP2) and Becke-3-Lee-Yang-Parr (B3LYP) calculations have been used to compare the geometrical parameters, hydrogen-bonding properties, vibrational frequencies and relative energies for several X- and X+ hydrogen peroxide complexes. The geometries and interaction energies were corrected for the basis set superposition error (BSSE) in all the complexes (1-5), using the full counterpoise method, yielding small BSSE values for the 6-311 + G(3df,2p) basis set used. The interaction energies calculated ranged from medium to strong hydrogen-bonding systems (1-3) and strong electrostatic interactions (4 and 5). The molecular interactions have been characterized using the atoms in molecules theory (AIM), and by the analysis of the vibrational frequencies. The minima on the BSSE-counterpoise corrected potential-energy surface (PES) have been determined as described by S. Simón, M. Duran, and J. J. Dannenberg, and the results were compared with the uncorrected PES

The effect of counterpoise correction and relaxation energy term to the internal rotation barriers: application to the BF3 ...NH3 and C2H4 ...SO2 dimers

The relevance of the fragment relaxation energy term and the effect of the basis set superposition error on the geometry of the BF3⋯NH3 and C2H4⋯SO2 van der Waals dimers have been analyzed. Second-order Møller-Plesset perturbation theory calculations with the d95(d,p) basis set have been used to calculate the counterpoise-corrected barrier height for the internal rotations. These barriers have been obtained by relocating the stationary points on the counterpoise-corrected potential energy surface of the processes involved. The fragment relaxation energy can have a large influence on both the intermolecular parameters and barrier height. The counterpoise correction has proved to be important for these systems

A chemical Hamiltonian approach study of the basis set superposition error changes on electron densities and one- and two-center energy components

A comparision of the local effects of the basis set superposition error (BSSE) on the electron densities and energy components of three representative H-bonded complexes was carried out. The electron densities were obtained with Hartee-Fock and density functional theory versions of the chemical Hamiltonian approach (CHA) methodology. It was shown that the effects of the BSSE were common for all complexes studied. The electron density difference maps and the chemical energy component analysis (CECA) analysis confirmed that the local effects of the BSSE were different when diffuse functions were present in the calculations

Effect of basis set superposition error on the electron density of molecular complexes

The effect of basis set superposition error (BSSE) on molecular complexes is analyzed. The BSSE causes artificial delocalizations which modify the first order electron density. The mechanism of this effect is assessed for the hydrogen fluoride dimer with several basis sets. The BSSE-corrected first-order electron density is obtained using the chemical Hamiltonian approach versions of the Roothaan and Kohn-Sham equations. The corrected densities are compared to uncorrected densities based on the charge density critical points. Contour difference maps between BSSE-corrected and uncorrected densities on the molecular plane are also plotted to gain insight into the effects of BSSE correction on the electron density

One- and two-center energy components in the atoms in molecules theory

The energy decomposition scheme proposed in a recent paper has been realized by performing numerical integrations. The sample calculations carried out for some simple molecules show excellent agreement with the chemical picture of molecules, indicating that such an energy decomposition analysis can be useful from the point of view of connecting quantum mechanics with the genuine chemical concepts

C-H···O H-bonded complexes: how does basis set superposition error change their potential-energy surfaces?

Geometries, vibrational frequencies, and interaction energies of the CNH⋯O3 and HCCH⋯O3 complexes are calculated in a counterpoise-corrected (CP-corrected) potential-energy surface (PES) that corrects for the basis set superposition error (BSSE). Ab initio calculations are performed at the Hartree-Fock (HF) and second-order Møller-Plesset (MP2) levels, using the 6-31G(d,p) and D95++(d,p) basis sets. Interaction energies are presented including corrections for zero-point vibrational energy (ZPVE) and thermal correction to enthalpy at 298 K. The CP-corrected and conventional PES are compared; the unconnected PES obtained using the larger basis set including diffuse functions exhibits a double well shape, whereas use of the 6-31G(d,p) basis set leads to a flat single-well profile. The CP-corrected PES has always a multiple-well shape. In particular, it is shown that the CP-corrected PES using the smaller basis set is qualitatively analogous to that obtained with the larger basis sets, so the CP method becomes useful to correctly describe large systems, where the use of small basis sets may be necessary