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991.
This work reported the investigation of the structural distortions and charge-transfer processes that occurred in the complex of cuprous(I) bis-2,9-dimethyl-1,10-phenanthroline upon oxidation to copper(II), , through a excited state of by density functional theory. The intramolecular electronic transfer from central metal-to-ligand (MLCT) upon the irradiation of light energy is confirmed. Due to this MLCT excitation, the structure of the excited state of is distorted and reorganized to adapt with the change of charge in central metal. As a result, the excited state of is formed, which has the similar electronic and structural properties with . The bulky substituents in 2- and 9-positions of the phenanthroline ligands can restrain the structural distort and decrease nonradiative decay rate. Thus, the electronic and steric effects of the ligands in the cuprous photo-sensitive complexes have important consequences in the behavior of their excited state.  相似文献   
992.
This paper employs the theory of planar dynamical systems and undetermined coefficient method to study travelling wave solutions of the dissipative (2 + 1)-dimensional AKNS equation. By qualitative analysis, global phase portraits of the dynamic system corresponding to the equation are obtained under different parameter conditions. Furthermore, the relations between the properties of travelling wave solutions and the dissipation coefficient r of the equation are investigated. In addition, the possible bell profile solitary wave solution, kink profile solitary wave solutions and approximate damped oscillatory solutions of the equation are obtained by using undetermined coefficient method. Error estimates indicate that the approximate solutions are meaningful. Based on above studies, a main contribution in this paper is to reveal the dissipation effect on travelling wave solutions of the dissipative (2 + 1)-dimensional AKNS equation.  相似文献   
993.
In this paper, the main topic is to investigate the intermittent property of the one-dimensional stochastic heat equation driven by an inhomogeneous Brownian sheet, which is a noise deduced from the study of the catalytic super-Brownian motion. Under some proper conditions on the catalytic measure of the inhomogeneous Brownian sheet, we show that the solution is weakly full intermittent based on the estimates of moments of the solution. In particular, it is proved that the second moment of the solution grows at the exponential rate. The novelty is that the catalytic measure relative to the inhomogeneous noise is not required to be absolutely continuous with respect to the Lebesgue measure on R.  相似文献   
994.
The mechanical excitation of solid bodies by a vibrating plate is not only an interesting fundamental problem, but also has relevance in many mechanical systems, for example, in the preparation of granular gases in microgravity. Herein, the energy input by an oscillating plate is numerically investigated as a function of the excitation parameters for selected Platonic solids and their behavior compared to that of a jumping sphere. The most important additional features, not relevant for spheres, are the excitation of body rotations and a permanent energy exchange between the rotational and translational degrees of freedom during the collisions with the plate. The distribution of kinetic energies is analyzed by a numerical simulation of the dynamics, using structures which emulate the mechanical behavior of regular polyhedra.  相似文献   
995.
The performance of glow discharge time‐of‐flight mass spectrometry in isotopic differentiation is revealed using the distribution of oxygen isotopes 16O and 18O in barrier‐type anodic alumina films as a focus. Anodic alumina films comprising 18O‐rich layers of controlled thickness were formed by the appropriate combination of anodising of superpure aluminium in electrolytes enriched with 18O isotopes and of natural abundance of 18O isotopes. Analysis of the elemental depth profiles of selected ionic species, i.e. 16O18O, allowed determination of the locations of the 18O‐rich layers and the 18O/16O interface. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
996.
YVO_4:Eu~(3+)纳米晶的水热合成与发光特性   总被引:1,自引:0,他引:1  
采用水热法在不同温度下制备了系列YVO4:Eu3+纳米晶。利用X射线衍射、电镜和荧光光谱对前驱体和系列样品的结构、形貌和发光性能进行了研究。XRD研究结果表明:合成的样品均为四方相YVO4,纳米晶的一次性粒径分布在13~44 nm。发射光谱和激发光谱的研究表明:特征发射峰来自于5D0-7FJ跃迁,激发带主要来自于Eu-O和V-O的电荷迁移带,发射强度和激发强度随样品结晶度的提高而增强。对样品5D0-7F2跃迁中来自于不同态的发射峰的相对强度进行了比较和讨论。  相似文献   
997.
长波敏化发光铕配合物纳米粒子的制备与表征   总被引:2,自引:0,他引:2  
以牛血清白蛋白(BSA)为保护剂, 利用沉淀法制备了平均粒径为35 nm的Eu(tta)3dpbt (dpbt = 2-(N,N-二乙基苯胺-4-基)-4,6-二(3,5-二甲基吡唑-1-基)-1,3,5-三嗪, tta = 噻吩甲酰三氟丙酮负离子)荧光纳米粒子. BSA保护Eu(tta)3dpbt纳米粒子在水中分散稳定性高, 光稳定性好, 长波敏化发光性能优良. 其在可见光区激发峰位于415 nm, 激发峰尾部延展至470 nm, 发光量子产率为0.20 (λex=415 nm, 25 ℃). 在近红外双光子激发下可发出纯正的红光, Eu(tta)3dpbt纳米粒子最大双光子激发作用截面为2.4×105 GM (λex=830 nm, 1 GM=10-50 cm4·s·photo-1·particle-1).  相似文献   
998.
We investigate the asymptotic profile to the Cauchy problem for a non‐linear dissipative evolution system with conservational form (1) provided that the initial data are small, where constants α, ν are positive satisfying ν2<4α(1 ? α), α<1. In (J. Phys. A 2005; 38 :10955–10969), the global existence and optimal decay rates of the solution to this problem have been obtained. The aim of this paper is to apply the heat kernel to examine more precise behaviour of the solution by finding out the asymptotic profile. Precisely speaking, we show that, when time t → ∞ the solution and solution in the Lp sense, where G(t, x) denotes the heat kernel and is determined by the initial data and the solution to a reformulated problem obtained in Section 3, β is related to ?+ and ?? which are determined by (41) in Section 4. The numerical simulation is presented in the end. The motivation of this work thanks to Nishihara (Asymptotic profile of solutions to nonlinear dissipative evolution system with ellipticity. Z. Angew Math Phys 2006; 57 : 604–614). Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
999.
We investigated the transition to spatio-temporal chaos in spatially extended nonlinear dynamical systems possessing an invariant subspace with a low-dimensional attractor. When the latter is chaotic and the subspace is transversely stable we have a spatially homogeneous state only. The onset of spatio-temporal chaos, i.e. the excitation of spatially inhomogeneous modes, occur through the loss of transversal stability of some unstable periodic orbit embedded in the chaotic attractor lying in the invariant subspace. This is a bubbling transition, since there is a switching between spatially homogeneous and nonhomogeneous states with statistical properties of on-off intermittency. Hence the onset of spatio-temporal chaos depends critically both on the existence of a chaotic attractor in the invariant subspace and its being transversely stable or unstable.  相似文献   
1000.
To monitor the beam profile at the end of the linac non-destructively,a wire scanner as a new diagnostic instrument was designed,manufactured and installed in 2007.Since then,several measurements have been carried out using this device.This paper describes the whole system of the wire scanner and the testing results.  相似文献   
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