Radiative and non-radiative decay of a single molecule close to a metallic nanoparticle

We study the spontaneous emission of a single emitter close to a metallic nanoparticle, with the aim to clarify the distance dependence of the radiative and non-radiative decay rates. We derive analytical formulas based on a dipole-dipole model, and show that the non-radiative decay rate follows a R⁻⁶ dependence at short distance, where R is the distance between the emitter and the center of the nanoparticle, as in Förster’s energy transfer. The distance dependence of the radiative decay rate is more subtle. It is chiefly dominated by a R⁻³ dependence, a R⁻⁶ dependence being visible at plasmon resonance. The latter is a consequence of radiative damping in the effective dipole polarizability of the nanoparticle. The different distance behavior of the radiative and non-radiative decay rates implies that the apparent quantum yield always vanishes at short distance. Moreover, non-radiative decay is strongly enhanced when the emitter radiates at the plasmon-resonance frequency of the nanoparticle.     

一类种内竞争模型的稳定性

一类种内竞争模型的稳定性曹贤通（郑州纺织工学院，郑州４５０００７）在本文中，我们研究一种按生殖能力不同而分类的种内竞争模型￣［１］这里，Ｊ（ｔ）和Ａ＿ｉ（ｔ）分别表示幼虫和第ｉ成虫群体的数量；ｎ＞０为固有净增长率￣［２］；０＜π≤１为幼虫到成虫的成活...     

求全局最优解的新算法

利用局部极大值点与动力系统的稳定奇点的对应性，计算代数方程的根、无约束极大值点、有约束极大值点、非线性规划解、及最小二乘解．我们采用了常微分方程数值解的Euler算法及网格初始点的循序迭代算法，并以具体的例子和程序说明创立的方法具有通用性，同时考虑了一些存在的问题以便在理论和算法上作进一步的改进。     

基于面向对象Petri网的业务流程建模方法研究

在信息系统开发过程中，信息系统建模的方法和模型的表示问题十分重要。本通过对面向对象Petri网的讨论，阐述了利用面向对象Petri网建立业务流程模型的基本问题，并给出了模型的计算机表示和存储方法。     

Extrapolation of isothermal retention data in gas chromatography for chiral recognition studies

Summary The calculation of capacity factors, k, from net retention times, t_R, and the corresponding dead times, t_M, at different temperatures suffers from the limited accuracy of the t_M values. If the temperature coefficient racy of the t_M values. If the temperature coefficient d ln k/d (1/T) only is required, it is sufficient to determine net retention times (t_R)_p at constant inlet pressure p_i for different temperatures, since the temperature dependence of (t_M)_p can be assumed as (t_M)_p=A·e^B/T, with B being approximately independent of the column inlet pressure and of the nature of the carrier gas. The extrapolation and interpolation of (t_R)_p may be either performed by linear regression or graphically with a nomogram for ln (t_R)_p versus 1/T. The resolution factor, , of two components, e.g. enantiomers which are resolved on a chiral stationary phase, can be treated in a similar way. Examples are given for the resolution of enantiomers of two non-proteinogenic amino acids on the new polysiloxane phase L-Chirasil-CPG.     

The design of a controller in Fuzzy Petri net

This paper designs a class of Fuzzy Petri net controller based on the character of place invariant in Petri net. This controller is simple in operation and is easy to put into practice. It has satisfying effects and can provide methods to do research in designing and optimizing the performance of system in solving the dead lock phenomenon in concurrent system.     

<Emphasis Type="Italic">ω</Emphasis>-Convergence theory of filters in <Emphasis Type="Italic">Lω</Emphasis> -spaces

In this paper, an ω-convergence theory of filters in an Lω-space is established. By means of the ω-convergence theory, some important characterizations with respective to the ω-closed sets, ω T ₂ separation and (ω ₁, ω ₂)-continuous mappings are obtained. Moreover, the mutual relationships among ω-convergence of molecular nets, ω-convergence of ideals and ω-convergence of filters are given.     

Enabling reduced-order data-driven nonlinear identification and modeling through naïve elastic net regularization

This work discusses an improved method of reduced-order modeling for existing data-driven nonlinear identification techniques through the incorporation of naïve elastic net regularization. The data-driven methods considered for this study operate using basis functions to represent the observed nonlinearity. Elastic net regularization is used to minimize the number of non-zero coefficients, thus modifying the basis functions and providing a compact representation. The ability of the naïve elastic net to provide reduced-order nonlinear models that can both accurately fit various data sets and computationally simulate new responses is illustrated through studies considering both synthetic data and experimental data. In both cases, the results obtained with the naïve elastic net are shown to match or outperform those from other traditional methods.     

Monotonicity preservation on triangles

It is well known that Bernstein polynomials on triangles preserve monotonicity. In this paper we define and study three kinds of monotonicity preservation of systems of bivariate functions on a triangle. We characterize and compare several of these systems and derive some geometric applications.