吩噻嗪卤代衍生物的荧光研究

本文主要研究了3-溴-N-乙基吩噻嗪(Br-P)在各种酸度、增敏溶剂、感光效应等条件下的荧光变换现象，并确定了最佳的发光体系。方法简单、准确可靠，其线性范围为1×10     

Mode-coupling approach to the dynamics of simple liquids

Summary A new derivation of the mode-coupling theory of liquid dynamics is presented which is applicable to both quantum and classical systems. A clear distinction between the basic underlying hyphotheses and the more technical approximations has been attempted. Asymptotic corrections to the dynamics of modes due to mode-coupling effects and selfconsistent mode-coupling theories emerge from the original idea as two markedly different branches of application. Paper presented at the workshop ?Highlights on Simple Liquids?, held in Turin at ISI on 1–3 May, 1989.     

A kinetic formulation for a model coupling free surface and pressurised flows in closed pipes

The aim of this paper is to present a kinetic formulation of a model for the coupling of transient free surface and pressurised flows. Firstly, we revisit the system of Saint-Venant equations for free surface flow: we state some properties of Saint-Venant equations, we propose a kinetic formulation and we verify that this kinetic formulation leads to a Gibbs equilibrium that minimises (in some general case) an energy and preserves the still water steady state. Secondly, we propose a model for pressurised flows in a Saint-Venant-like conservative formulation. We then propose a kinetic formulation and we verify that this kinetic formulation leads to a Gibbs equilibrium that minimises in any case an energy and preserves the still water steady state. Finally, we propose a dual model that couples these two types of flow.     

Hamiltonian and Brownian systems with long-range interactions: IV. General kinetic equations from the quasilinear theory

We develop the kinetic theory of Hamiltonian systems with weak long-range interactions. Starting from the Klimontovich equation and using a quasilinear theory, we obtain a general kinetic equation that can be applied to spatially inhomogeneous systems and that takes into account memory effects. This equation is valid at order 1/N in a proper thermodynamic limit and it coincides with the kinetic equation obtained from the BBGKY hierarchy. For N→+∞, it reduces to the Vlasov equation governing collisionless systems. We describe the process of phase mixing and violent relaxation leading to the formation of a quasistationary state (QSS) on the coarse-grained scale. We interpret the physical nature of the QSS in relation to Lynden-Bell’s statistical theory and discuss the problem of incomplete relaxation. In the second part of the paper, we consider the relaxation of a test particle in a thermal bath. We derive a Fokker-Planck equation by directly calculating the diffusion tensor and the friction force from the Klimontovich equation. We give general expressions of these quantities that are valid for possibly spatially inhomogeneous systems with long correlation time. We show that the diffusion and friction terms have a very similar structure given by a sort of generalized Kubo formula. We also obtain non-Markovian kinetic equations that can be relevant when the auto-correlation function of the force decreases slowly with time. An interesting factor in our approach is the development of a formalism that remains in physical space (instead of Fourier space) and that can deal with spatially inhomogeneous systems.     

Photocatalytic degradation of dimethyl phthalate in aqueous TiO2 suspension: a modified Langmuir–Hinshelwood model

A modified Langmuir–Hinshelwood model based on intrinsic reactions was proposed. Similar to the Langmuir–Hinshelwood model, the modified model predicts that both the reciprocal of reaction rate constant 1/k _r and the adsorption rate constant K _s are linearly proportional to the reciprocal of the square root of light intensity 1/I ^1/2 . The validity of the modified kinetic model was verified with the experimental data of dimethyl phthalate (DMP) degradation.     

Towards Realization of a Micro- and Mesoporous Composite Silicate Catalyst

A composite silicate material, which possesses the characteristics of both microporous zeolite and mesoporous silica materials, is developed by top–down and bottom–up synthesis techniques. In order to realize a micro- and mesoporous composite material, several essential points must be clarified, since each porous material is synthesized under very different metastable conditions: zeolite is a silicate crystal, while the wall of mesoporous material is composed of amorphous silicate. Here, some aspects of the realization of a micro- and mesocomposite porous material are described, as are our experimental results regarding the successful production of composite catalyst.     

Kinetics of hydrolysis of some new heterocyclic azomethines

Kinetics of base hydrolysis of new heterocyclic azomethines derived from active methyl quaternary salts and aromatic nitroso compounds were investigated in the presence of 70% (wt/wt) water-methanol. The base hydrolysis of these compounds is strictly first-order with respect to OH^– and azomethine. The rate determining step is suggested to be the attack of the hydroxide ion on the free base. Effects of water content and nature of organic hydroxylic solvent have been studied. It is concluded that specific solute-solvent interactions through dispersion forces play a major role in the base hydrolysis rate of the azomethines investigated. The effect of pH (2.98 – 12.24) on hydrolysis rates of compounds having a diethylamino substituent in the presence of 30% methanol has been studied. In acidic media, the rate determining step is probably the water attack on the protonated substrate.     

Kinetic interface roughening and magneto resistance of sputter-deposited Fe/Ni75B25 multilayers

The roughening of interfaces as a function of layer thickness and magneto transport properties have been investigated on sputter-deposited Fe/Ni₇₅B₂₅ multilayer films. X-ray reflectivity data were recorded for Ni₇₅B₂₅(72 nm) film and for [Fe(2 nm)/Ni₇₅B₂₅(2 nm)]₁₆ and [Fe(4 nm)/Ni₇₅B₂₅(4 nm)]₈ multilayer films. A power law dependence of the interfacial width of growing Fe/Ni₇₅B₂₅ interfaces was observed. The resulting growth exponents β were found to be in the range of 0.55–0.58 in the initial growth stage of the multilayer with lower Fe/Ni₇₅B₂₅ repetition thickness and at approximately 0.34 for multilayer with higher repetition thickness. The growth exponents were compared with theoretical calculations. High resolution electron microscopy revealed the columnar growth of the Fe/Ni₇₅B₂₅ multilayer. Additionally, an increase of magnetoresistance was observed by the multilayering of Ni₇₅B₂₅ films with Fe interlayers.     

新催化动力学光度法测定微量铁的研究--棓花青-O2指示反应体系

在 p H 7.0的磷酸盐缓冲体系中 ,微量铁 ( )能显著催化溶解氧氧化木立口 花青褪色。研究了该指示反应的催化动力学行为 ,建立了测定微量铁的新催化动力学分析法 ,方法线性测定范围 0 .0 5～ 0 .6μg· m L- 1 ,检出限为 0 .0 1 μg· m L- 1 。本法选择性和重现性好 ,反应体系简单易于控制。用其测定了自来水、人发及面粉等样品中的铁 ,结果满意。     

Reaction pathways to dimer in polystyrene pyrolysis: A mechanistic modeling study

A detailed mechanistic model for polystyrene pyrolysis was created that built on a modeling framework developed in our previous work and was used to probe three competing pathways to dimer formation: benzyl radical addition, 1,3-hydrogen shift, and 7,3-hydrogen shift, based on recent literature reports. To incorporate the chemistry involved in the 7,3-hydrogen shift pathway, the 1,7- and 7,3-hydrogen shift reaction families were added to the model. The updated version of the model tracks 75 species and over 3500 reactions. Rate parameters for all families were specified based on our previous work, more recent literature reports, and regression against limited experimental data. The model was able to accurately predict the experimental results for polystyrene pyrolysis for different reactor configurations for a temperature range of 100 °C and two orders of magnitude of initial molecular weight for experimental data collected in our own lab and from Bouster and coworkers and Bockhorn and coworkers. The results from our model were studied using net rate analysis to gain insight into the competitiveness of the various reaction pathways to dimer formation. The net rate analysis demonstrated that 7,3-hydrogen shift is the dominant reaction pathway to dimer formation at the temperatures studied. Benzyl radical addition becomes a more competitive reaction pathway as the temperature increases, which is caused predominantly by an increase in the benzyl radical concentration with increasing temperature. Overall, it is quantitatively shown that both 7,3-hydrogen shift and benzyl radical addition are important pathways for dimer formation, with their relative competitiveness influenced by temperature.